Common Information Model for Power System Dynamics Standard Dynamic Model Reference Document DRAFT October 28, 2008 Introduction ............................................................................................................................................................................. 4 Standard Interconnections ................................................................................................................................................... 5 Synchronous Generator Unit............................................................................................................................................................................. 5 Asynchronous (Induction) Generator Unit ................................................................................................................................................... 7 Large Synchronous Motor Unit ........................................................................................................................................................................ 8 Large Asynchronous (Induction) Motor Unit............................................................................................................................................... 9 Aggregate Load.....................................................................................................................................................................................................10 Synchronous Generator Models......................................................................................................................................... 11 genSync - Synchronous Generator Model ..............................................................................................................................................13 genSync - RoundRotor Type....................................................................................................................................................................17 genSync - Salient Pole Type......................................................................................................................................................................19 genSync - Transient Type .........................................................................................................................................................................20 genSync - TypeF.............................................................................................................................................................................................20 genSync - TypeJ .............................................................................................................................................................................................21 genSync - CrossCompound Type...........................................................................................................................................................22 genEquiv - Equivalent (Classical ) Generator Model..............................................................................................................................24 Asynchronous Generator Models ...................................................................................................................................... 26 genAsync - Asynchronous Generator Model...........................................................................................................................................28 Large Synchronous Motor Models ..................................................................................................................................... 31 motorSync - Synchronous Motor Model....................................................................................................................................................33 motorSync - RoundRotor Type...............................................................................................................................................................38 motorSync - Salient Pole Type.................................................................................................................................................................40 Large Asynchronous Motor Models................................................................................................................................... 41 motorAsync - Asynchronous Motor Model...............................................................................................................................................42 Voltage Compensation Models .......................................................................................................................................... 45 vcompIEEE - IEEE Voltage Compensation Model....................................................................................................................................47 vcompCross – Cross-Compound Voltage Compensation Model.....................................................................................................48 Excitation System Models.................................................................................................................................................... 49 excAC1A - IEEE AC1A Model ............................................................................................................................................................................51 excAC2A - IEEE AC2A Model ............................................................................................................................................................................53 excAC3A - IEEE AC3A Model ............................................................................................................................................................................55 excAC4A - IEEE AC4A Model ............................................................................................................................................................................57 excAC5A - IEEE AC5A Model ............................................................................................................................................................................59 excAC6A - IEEE AC6A Model ............................................................................................................................................................................61 excAC7B - IEEE AC7B Model ............................................................................................................................................................................63 Page 2 excAC8B - IEEE AC8B Model ............................................................................................................................................................................65 excDC1A - IEEE DC1A Model............................................................................................................................................................................67 excDC2A - IEEE DC2A Model............................................................................................................................................................................69 excDC3A - IEEE DC3A Model............................................................................................................................................................................71 excDC4B - IEEE DC4B Model............................................................................................................................................................................73 excST1A - IEEE ST1A Model..............................................................................................................................................................................75 excST2A - IEEE ST2A Model..............................................................................................................................................................................77 excST3A - IEEE ST3A Model..............................................................................................................................................................................79 excST4B - IEEE ST4B Model..............................................................................................................................................................................81 excST5B - IEEE ST5B Model..............................................................................................................................................................................83 excST6B - IEEE ST6B Model..............................................................................................................................................................................85 excST7B - IEEE ST7B Model..............................................................................................................................................................................87 Other Excitation System Models To Be Added.........................................................................................................................................89 Power System Stabilizer (PSS) Models ............................................................................................................................... 90 pssIEEE2B - IEEE PSS2B Power System Stabilizer Model .................................................................................................................92 Other PSS Models To Be Added......................................................................................................................................................................94 Turbine-Governor Models ................................................................................................................................................... 95 govHydro – Hydro Turbine-Governor Model ............................................................................................................................................97 Other Turbine-Governor Models To Be Added.........................................................................................................................................99 Aggregate Load Models..................................................................................................................................................... 100 loadStatic - Static Load Model...................................................................................................................................................................102 loadMotor - Aggregate Induction Motor Load ...................................................................................................................................104 Mechanical Load Models ................................................................................................................................................... 107 mechload1 - Mechanical Load Model 1 ................................................................................................................................................108 Page 3 Introduction The CIM standard dynamic models include most models for power system equipment that are commonly used for analysis of power system dynamic simulations in the transient and oscillatory stability time scale as defined by IEEE / CIGRE Standard Terms and Definitions for Power System Stability Analysis [ref]. Each of the models is described in this document, grouped by type of model. Page 4 Standard Interconnections This section describes the standard interconnection of models for various types of equipment. These interconnections are understood by the application programs and therefore do not need to be communicated with the CIM data. In the interconnection diagrams, a dashed box means that a model does not have to be present. Synchronous Generator Unit A synchronous generator and its related equipment models are associated with a generator in the static (power flow) data and have the standard interconnections shown in the following figure. Etr, Eti Voltage Compensator Vcomp PSS inputs Vref Vs PSS Itr, Iti Network Algebraic Equations Itr2, Iti2 Efd Excitation System Ifd Synchronous Generator generator terminal bus speed Pref Pmech Turbine-Governor Pmech2 Generator #2 Notes: 1. The interface between the generator model and the network algebraic equations is application dependent. The variables used for this interface do not need to be identified since they are internal to the application program and will not be used by other models. 2. If no Excitation System model is present for a unit, the field voltage (Efd) is held constant at the initial value. 3. If no Turbine-Governor model is present for a unit, the generator mechanical power (Pmech) is held constant at the initial value. 4. If no PSS model is present for a unit, the Vs signal is zero. The PSS model may have any of several variables as inputs. The identification of the type of variable and its source is part of the data for the PSS model. Page 5 5. If no Voltage Compensator is present for at unit, Vcomp is set equal to the magnitude of the terminal voltage. 6. Generator #2 is the second unit of a cross-compound pair of generators and is usually connected to the same terminal bus. A single Turbine-Governor model determines the mechanical power for both units. A Voltage Compensator model that uses the currents from both units may be used. Therefore, the Turbine-Governor and Voltage Compensator models must have provision for being associated with two generating units. 7. The Vref and Pref variables are shown because they are standard inputs to the Excitation System and Turbine-Governor, respectively. These variables may be the output of nonstandard models, e.g. for secondary voltage and frequency controls. Page 6 Asynchronous (Induction) Generator Unit An asynchronous generator and its related equipment models are associated with a generator in the static (power flow) data and have the standard interconnections shown in the following figure. This is for a “squirrel-cage” induction machine or a wound-rotor induction machine with shortcircuited field windings. Other models and interconnections are required for a wound-rotor machine with external connections to the field windings. Network Algebraic Equations speed Pref Turbine -Governor Pmech Asynchronous Generator generator terminal bus Notes: 1. The interface between the generator model and the network algebraic equations is application dependent. The variables used for this interface do not need to be identified since they are internal to the application program and will not be used by other models. 2. If no Turbine-Governor model is present for a unit, the generator mechanical power (Pmech) is held constant at the initial value. Page 7 Large Synchronous Motor Unit A synchronous motor and its related equipment models are associated with a generator (with negative Pgen) in the static (power flow) data and have the standard interconnections shown in the following figure. Etr, Eti PSS inputs Voltage Compensator Vcomp Vref PSS Vs Itr, Iti Network Algebraic Equations Efd Excitation System Ifd Synchronous Motor generator terminal bus speed Mechanical Load Pmech Notes: 1. The interface between the motor model and the network algebraic equations is application dependent. The variables used for this interface do not need to be identified since they are internal to the application program and will not be used by other models. 2. If no Excitation System model is present for a unit, the field voltage (Efd) is held constant at the initial value. 3. If no Mechanical Load model is present for a unit, the motor mechanical power (Pmech) is held constant at the initial value. 4. If no PSS model is present for a unit, the Vs signal is zero. The PSS model may have any of several variables as input. The identification of the type of variable and its source is part of the data for the PSS model. 5. If no Voltage Compensator is present for at unit, Vcomp is set equal to the magnitude of the terminal voltage. Page 8 Large Asynchronous (Induction) Motor Unit An asynchronous motor and its related equipment models are associated with a generator (with negative Pgen) in the static (power flow) data and have the standard interconnections shown in the following figure. This is for a “squirrel-cage” induction machine or a wound-rotor induction machine with short-circuited field windings. Other models and interconnections are required for a wound-rotor machine with external connections to the field windings. Network Algebraic Equations speed Mechanical Load Pmech Asynchronous Motor generator terminal bus Notes: 1. The interface between the motor model and the network algebraic equations is application dependent. The variables used for this interface do not need to be identified since they are internal to the application program and will not be used by other models. 2. If no Mechanical Load model is present for a unit, the motor mechanical power (Pmech) is held constant at the initial value. Page 9 Aggregate Load An aggregate load is associated with a load in the static (power flow) data and has the standard interconnection shown in the following figure. Vbus, fbus Network Algebraic Equations Load Model Pload Qload load terminal bus Load Model Standard Interconnections Notes: 1. The interface between the model and the network algebraic equations is application dependent. The variables used for this interface do not need to be identified since they are internal to the application program and will not be used by other model. a. For static (non-dynamic) load models, the P and Q consumption of the load is determined as a function of the magnitude and frequency of the voltage at the terminal bus. b. For dynamic load models, the interface is similar to that of a generator model. Page 10 Synchronous Generator Models For conventional power generating units (e.g., thermal, hydro, combustion turbine), a synchronous machine model represents the electrical characteristics of the generator and the mechanical characteristics of the turbine-generator rotational inertia. The standard interconnection variables between a synchronous generator model and other models are shown in the following figure and table: Efd Excitation System E”d, E”q* Ifd Synchronous Generator speed Turbine Governor angle Network Equations Id, Iq* Pmech * Network interface variables may differ among application programs Synchronous Generator Interconnection Variables The interconnection with the electrical network equations may differ among application programs. The program only needs to know the terminal bus and generator ID to establish the correct interconnection. Synchronous Generator Interconnection Variables Model Type Inputs: Name Synchronous Generator Units Description Source Efd Pmech p.u. p.u. Field voltage on base of Ifag * Rfd (field resistance) Mechanical shaft power to the generator Outputs: Name Speed Angle Units p.u. radians Eppd Eppq Ifd p.u. p.u. p.u. Description Generator (electrical) speed Generator rotor angle relative to synchronously-rotating reference frame Direct-axis subtransient voltage Quadrature-axis subtransient voltage Field current on Ifag base Page 11 Exciter Turbine The following variables may be calculated in the generator model or in the network solution depending on the particular application program: Pgen p.u. Electrical power Qgen p.u. Reactive power Eterm p.u. Terminal voltage Iterm p.u. Terminal current magnitude Initialization Inputs: Name Units Eterm busAngle Pgen Qgen p.u. radians MW MVAr Description Terminal voltage magnitude Terminal voltage angle relative to system reference Electrical power Reactive power Source Power Flow Power Flow Power Flow Power Flow Initialization Outputs: Name Units Description Speed p.u. Generator (electrical) speed (= 1.0 initially) Angle radians Generator rotor angle relative to synchronously-rotating reference frame Efd p.u. Field voltage on base of Ifag * Rfd (field resistance) Ifd p.u. Field current on Ifag base (= Efd initially) Pmech p.u. Mechanical shaft power to the generator Notes: 1. Input/output variable units (except for angle) should be kept in per unit. Attempts to convert to engineering units would be confusing. Since these variable are not directly attributes of CIM classes, this should not conflict with CIM standards. 2. The interface between the generator model and the network algebraic equations is application dependent. The variables used for this interface do not need to be specified since they are internal to the application program and will not be used by other models, e.g. user-written models. 3. If no Excitation model is present for a unit, the field voltage (Efd) should be held constant at the initial value. 4. If no Turbine-Governor model is present for a unit, the generator mechanical power (Pmech) should be held constant at the initial value. References Most of the standard synchronous machine models are based on modeling practices described in IEEE Standard 1110-1991, “IEEE Guide for Synchronous Generator Modeling Practices in Stability Analysis.” Page 12 genSync - Synchronous Generator Model A single standard synchronous model is defined for the CIM, with several variations indicated by the “model type” attribute. This model can be used for all types of synchronous machines (salient pole, solid iron rotor). A simplified model (genEquiv) is also defined below for representation of groups of generators that are not modeled in detail. All types of the genSync model use a subset of the same data parameters and input/output variables The input parameters are shown in the following table: Model Name genSync Description Synchronous generator model with several variations Parameters: Parameter Name Bus number Unit ID Model Type MVAbase kVbase Ra Xl Xd Xpdv Usual Units CIM Units?? Typical Value None MVA kV p.u. p.u. p.u. p.u. Xppdv p.u. 0.2 Xq Xpq Xppq Tpdo Tppdo Tpqo Tppqo H (note 2) D (note 3) S1 (note4) S12 (note 4) p.u. p.u. p.u. sec. sec. sec. sec. sec. none none none none none none 1.6 0.3 0.2 5.0 0.03 0.5 0.03 3.0 0.0 0.02 0.12 Ks Pfrac none none none none 0.0 1.0 None MVA kV 0.005 0.15 1.8 0.5 sec. sec. sec. sec. Description Terminal bus number in power flow case Generator ID in power flow case See table below MVA base for p.u. values kV base for p.u. values Stator resistance (>= 0.) Stator leakage reactance (> 0.) D-axis synchronous reactance (>= Xpdv) D-axis transient reactance (unsaturated) (> =X”dv) D-axis sub-transient reactance (unsaturated) (> Xl) Q-axis synchronous reactance (> =Xpq) Q-axis transient reactance (> =Xppq) Q-axis sub-transient reactance (> Xl) D-axis transient rotor time constant (> Tppdo) D-axis sub-transient rotor time constant (> 0.) Q-axis transient rotor time constant (> Tppqo) Q-axis sub-transient rotor time constant (> 0.) Inertia constant of turbine-generator (> 0.) Damping factor Saturation factor at rated term. voltage (>= 0.) Saturation factor at 120% of rated term. voltage (>=S1) Saturation loading correction factor (>= 0.) Fraction of power flow generator P (>= 0.) 1. Generator parameters such as Xl, Xd, etc. are actually used as inductances (L) in the models, but are commonly referred to as reactances since, at nominal frequency, the per unit values are the same. However, some references (e.g. PSLF User Manual) use the Page 13 symbol L instead of X. Also, the “p” in the parameter names is a substitution for a “prime” in the usual notation, e.g. Xppd refers to X”d. 2. H is the stored energy in the rotating mass of the generator plus all other elements (turbine, exciter) on the same shaft and has units of MW-sec. Conventional units are per unit on the generator MVA base, usually expressed as MW-sec./MVA or just sec. (since MW and MVA are equivalent units). 3. D has units of power/speed but is regarded as a dimensionless factor resulting from linearization of an exponential relationship between speed and power: P = Po (ω)D . This value is often zero when the source of damping torques (generator damper windings, load damping effects, etc.) are modeling in detail. [ref] 4. Saturation factors (S1, S12) are defined by S(E1) and S(E2) in Figure genSync1 OPEN CIRCUIT VOLTAGE AIR GAP LINE OPEN CIRCUIT MAGNETIZATION CURVE E2 OBi - OAi S(E) = --------------OAi E1 For generators E1 = 1.0 E2 = 1.2 For Exciters E1, E2 are parameters 0 A1 B1 A2 B2 MAGNETIZING CURRENT Figure genSync1 -- Synchronous Generator Saturation Parameters Note: The quantity OA1 in amperes is normally called Ifag -- Field current at rated voltage, open circuit on the air gap (no saturation) line. Page 14 Model Equations: The mechanical equations for all variatons of the genSync model are the same and can be represented by the following block diagram: 1. Te Pmech d n Σ n/d Tm + _ Σ _ + ω Σ + ∆ω 1 2Hs speed ωo s angle D Figure genSync2 -- Synchronous Generator Mechanical Equation Block Diagram All variables are per unit on generator MVA base except angle, which is in radians. ωo is the system synchronous frequency in radians per second, e.g. 377. for 60Hz. systems. The electrical equations for all variations of the genSync model are based on the following equivalent circuit diagram for the direct and quadrature axes: Ra Xl Rfd Xfd Rkd efd Xad d axis + Xkd Ra Xl R1q X1q R2q q axis Xaq X2q Figure genSync3 -- Synchronous Generator Equivalent Circuit Page 15 In each axis, the branches represent the stator leakage reactance (Xl) and resistance (Ra), the magnetizing reactance (Xad, Xaq), the physical field winding (Rfd, Xfd, efd) on the rotor, and equivalent windings for eddy current flow in the rotor iron. This equivalent circuit makes the assumption of equal mutual inductance among all of the windings (rotor to stator, rotor d to rotor q). Models based on unequal mutual inductance are not normally used for stability analysis. The definition of d and q axis variables is based on the following phasor diagram (counterclockwise rotation), for the case of an overexcited generator (generating Q): q axis j It ( Xq-X”) E” rotor angle Et bus angle It It (Ra + jX”) Network Reference d axis Figure genSync4 -- Synchronous Generator Phasor Diagram The relationships between the equivalent circuit parameters and the standard model parameters are as follows: Xd = Xad + Xl X’d = Xl + Xad * Xfd / (Xad + Xfd) X”d = Xl + Xad * Xfd* Xkd / (Xad * Xfd + Xad * Xkd + Xfd * Xkd) T’do = (Xad + Xfd) / (wo * Rfd) T”do = (Xad * Xfd + Xad * Xkd + Xfd * Xkd) / (wo * Rkd * (Xad + Xfd) Xq = Xaq + Xl X’q = Xl + Xaq * X1q / (Xaq+ X1q) X”q = Xl + Xaq * X1q* X2q / (Xaq * X1q + Xaq * X2q + X1q * X2q) T’qo = (Xaq + X1q) / (wo * R1q) T”qo = (Xaq * X1q + Xaq * X2q + X1q * X2q)/ (wo * R2q * (Xaq + X1q) The several variations of the genSync model described on the following pages differ in the following ways: • The number of equivalent windings that are included • The way in which saturation is incorporated into the model. Page 16 • • Whether or not “subtransient saliency” (Xppq ≠ Xppdv) is represented. Whether or not multiple units (e.g. cross-compound set) are represented individually in the static (power flow) data. Variations of the genSync model are identified by the “model type” attribute as shown in the table below, together with the corresponding model names in each application program. Each model type is described in detail on the following pages. CIM Model Type RoundRotor SalientPole Transient TypeF TypeJ CrossCompound PSLF Model genrou gensal (genrou) gentpf gentpj gencc PSS/E Model GENROU GENSAL GENTRA DigSilent Model ElmSym ElmSym ElmSym Eurostag Model GENROU? Note: It is not necessary for each program to have separate models for each of the model types. The same model can often be used for several types by alternative logic within the model. Also, differences in saturation representation may not result in significant model performance differences so model substitutions are often acceptable. genSync - RoundRotor Type The complete equivalent circuit is used with two rotor windings in each axis. Notes: • • • Xppq is assumed to be equal to Xppd (no subtransient saliency) Saturation is modeled in both the d and q axes as shown in the block diagram The following input parameters are not used: Xppq, Ks, Pfrac Block Diagram: Page 17 iq Efd Σ 1 sT' do 1 sT' ' do Σ ψkd X' d − X' ' d ( X' d − Xl) * *2 Σ Ifd ω X' ' d − Xl X' d − Xl ψfd X' d − X' ' d X' d − Xl Σ X'd-Xl ψ"d Ra Eq Π Σ X''d d-AXIS id Σ Xd-X'd ψ" = sqrt(ψ"d2+ψ"d2) ψ" d Se ψ"q Xq − Xl Xd − Xl Xq-X'q Σ Σ X' q − X' ' q ( X' q − Xl) * *2 ψ1q Σ 1 sT' qo Σ 1 sT' ' qo iq q-AXIS X'q-Xl ψ2q X' q − X' q X' q − Xl X' ' q − Xl X' q − Xl X''q ψ"q Σ Π Σ Ed ω Ra id Figure genSync5 -- genSync – RoundRotor Type Model Block Diagram Page 18 genSync - Salient Pole Type The d-axis equivalent circuit is the same as for the RoundRotor type. The q-axis has only one equivalent rotor winding, which may be labeled as transient (Xpq) or subtransient (Xppq) – Xpq is used for the CIM description. Notes: • • • Xppq (=Xpq) is assumed to be equal to Xppdv (no subtransient saliency) Saturation is modeled in the d axis only as shown in the block diagram The following input parameters are not used: Xpq, Xppq, Tppqo, Ks, Pfrac Block Diagram: iq Efd Σ 1 sT' do ω X' ' d − Xl X' d − Xl ψfd 1 sT' ' do Σ ψkd X' d − X' ' d X' d − Xl X' d − X' ' d ( X' d − Xl) * *2 Σ X'd-Xl ψ"d Ra Eq Π Σ X''d d-AXIS Se ψfd Ifd Σ Xd-X'd id Σ iq Xq-X'q X''q q-AXIS Σ 1 sT' qo ψ1q ψ" q Π Σ Ed ω Ra id Figure genSync6 -- genSync – SalientPole Type Model Block Diagram Page 19 genSync - Transient Type The d-axis equivalent circuit has only the field winding. The q-axis has only one equivalent rotor winding, which may be labeled as transient (Xpq) or subtransient (Xppq) – Xpq is used for the CIM description. Notes: • • • ??? Xppq (=Xpq) is assumed to be equal to Xppdv (=Xpd) (no subtransient saliency) Saturation is modeled in the d axis only as shown in the block diagram The following input parameters are not used: Xppd, Xpq, Xppq, Tpdo, Tppqo, Ks, Pfrac Block Diagram: Add figure later Figure genSync7 -- genSync – Transient Type Model Block Diagram genSync - TypeF This model has a similar level of detail to the RoundRotor type but permits subtransient saliency (Xppq ≠ Xppdv) and models saturation differently. The RoundRotor type can usually be substituted without significant loss of accuracy. Notes: • • Saturation is modeled in both the d and q axes as shown in the block diagram The following input parameters are not used: Ks, Pfrac Block Diagram: Page 20 Ld − L' d L' d − L ' ' d ∑ Efd 1 sT' do Se E’q Se ∑ Ld − L" d L' d − L' ' d 1 sT' ' do L’d - L”d ϕ" d E”q id Se = 1. + fsat( ϕag) Q − Axis similar except : Se = 1. + Lq ( ϕag) Ld Figure genSync9 -- genSync – TypeF Model Block Diagram genSync - TypeJ This model is the same as TypeF but includes the effect of generator loading on saturation. Notes: • • Saturation is modeled in both the d and q axes as shown in the block diagram The following input parameters are not used: Pfrac Block Diagram: Page 21 Ld − L' d L' d − L' ' d ∑ Efd 1 sT' do Se E’q Se ∑ Ld − L" d L' d − L' ' d 1 sT' ' do L’d - L”d ϕ" d E”q id Se = 1. + fsat(ϕag + Kis ∗ It ∗ sign(id)) Q − Axis similar except : Se = 1. + Lq ∗ fsat (ϕag + Kis ∗ It ∗ sign(id)) Ld Figure genSync10 -- genSync – TypeJ Model Block Diagram genSync - CrossCompound Type This model is the same as RoundRotor Type but permits more than one genSync model to split the generator power from the power flow synchrounous machine model. This is most often used for representing the two untis of a cross-compound set which always operate together from the same steam supply. Notes: • • • • The parameter Pfrac is the fraction of the power flow Pgen and Qgen supplied by this unit. Xppq is assumed to be equal to Xppd (no subtransient saliency) Saturation is modeled in both the d and q axes as shown in the block diagram The following input parameters are not used: Xppq, Ks Block Diagram: Page 22 iq Efd Σ 1 sT' do 1 sT' ' do Σ ψkd X' d − X' ' d ( X' d − Xl) * *2 Σ Ifd ω X' ' d − Xl X' d − Xl ψfd X' d − X' ' d X' d − Xl Σ X'd-Xl ψ"d Ra Eq Π Σ X''d d-AXIS id Σ Xd-X'd ψ" = sqrt(ψ"d2+ψ"d2) ψ" d Se ψ"q Xq − Xl Xd − Xl Xq-X'q Σ Σ X' q − X' ' q ( X' q − Xl) * *2 ψ1q Σ 1 sT' qo Σ 1 sT' ' qo iq q-AXIS X'q-Xl ψ2q X' q − X' q X' q − Xl X' ' q − Xl X' q − Xl X''q ψ"q Σ Π Σ Ed ω Ra id Figure genSync11 -- genSync – CrossCompound Type Model Block Diagram Page 23 genEquiv - Equivalent (Classical ) Generator Model This model represents a synchronous generator as a constant internal voltage behind an impedance (Ra +jXpdv) as shown in the following equivalent circuit: Notes: • • • • Since internal voltage is held constant, there is no genEfd input and any excitation system model will be ignored. There is also no genIfd output. This model should never be used for representing a real generator except, perhaps, small generators whose response is insignificant. The model is often used for gross equivalents of parts of a system that are not represented in detail. In this case. the MVA rating would be the combined rating of all generators in the equivalenced area. Ra + jXpdv would be the short circuit equivalent impedance at the location of the equivalent generator on the generator MVA rating base. H and D would be typical or average values for the generators in the equivalenced area. The internal reactance may be labeled in different ways (Xp, Xpp, Xpd, Xppd) by different programs. The Xpdv value from the genSync input data is selected for use by the CIM model. Block Diagram: The mechanical equations for the genEquiv model are the same as for genSync as shown in Figure genSync2. Add figure later Figure genEquiv1 -- Equivalent (Classical) Model Block Diagram CIM Model Name genEquiv PSLF Model gencls PSS/E Model GENCLS DigSilent Model ElmSym Eurostag Model Parameters: Parameter Name Bus number Unit ID Model Type MVAbase kVbase Ra Xpdv Page 24 Usual Units None MVA kV p.u. p.u. CIM Units?? None MVA kV ohms ohms Typical Value 0.005 0.5 Description Terminal bus number in power flow case Generator ID in power flow case See table below MVA base for p.u. values kV base for p.u. values Stator resistance (>= 0.) D-axis transient reactance (unsaturated) (> 0.) H D sec.* none** MW-sec. none 3.0 0.0 Inertia constant of turbine-generator (> 0.) Damping factor 1. Parameter Xpd is actually used as an inductance (L) in the model, but is commonly referred to as a reactance since, at nominal frequency, the per unit values are the same. However, some references (e.g. PSLF User Manual) use the symbol L instead of X. Also, the “p” in the parameter name is a substitution for a “prime” in the usual notation, e.g. Xpd refers to X’d. 2. H is the stored energy in the rotating mass of the generator plus all other elements (turbine, exciter) on the same shaft and has units of MW-sec. Conventional units are per unit on the generator MVA base, usually expressed as MW-sec./MVA or just sec. (since MW and MVA are equivalent units). 3. D has units of power/speed but is regarded as a dimensionless factor resulting from linearization of an exponential relationship between speed and power: P = Po (ω)D . This value is often zero when the source of damping torques (generator damper windings, load damping effects, etc.) are modeling in detail. [ref] Page 25 Asynchronous Generator Models The standard interconnection variables between an asynchronous generator model and other models are shown in the following figure and table: E”d, E”q* speed Turbine Governor Network Equations Asynchronous Generator Id, Iq* Pmech * Network interface variables may differ among application programs Asynchronous Generator Interconnection Variables The interconnection with the electrical network equations may differ among application programs. The program only needs to know the terminal bus and generator ID to establish the correct interconnection. Asynchronous Generator Interconnection Variables Model Type Inputs: Name Asynchronous Generator Units Pmech p.u. Outputs: Name Speed Eppd Eppq Units p.u. p.u. p.u. Description Mechanical shaft power to the generator Source Turbine Description Generator (electrical) speed Direct-axis subtransient voltage Quadrature-axis subtransient voltage The following variables may be calculated in the generator model or in the network solution depending on the particular application program: Pgen p.u. Electrical power Qgen p.u. Reactive power Eterm p.u. Terminal voltage Iterm p.u. Terminal current magnitude Page 26 Initialization Inputs: Name Units Eterm busAngle Pgen Qgen p.u. radians MW MVAr Description Terminal voltage magnitude Terminal voltage angle relative to system reference Electrical power Reactive power Source Power Flow Power Flow Power Flow Power Flow Initialization Outputs: Name Units Description Speed p.u. Generator (electrical) speed (= 1.0 initially) Pmech p.u. Mechanical shaft power to the generator Notes: 1. Input/output variable units should be kept in per unit. Attempts to convert to engineering units would be confusing. Since these variable are not directly attributes of CIM classes, this should not conflict with CIM standards. 2. The interface between the generator model and the network algebraic equations is application dependent. The variables used for this interface do not need to be specified since they are internal to the application program and will not be used by other models, e.g. user-written models. 3. If no Turbine-Governor model is present for a unit, the generator mechanical power (Pmech) should be held constant at the initial value. Page 27 genAsync - Asynchronous Generator Model The genAsynch model represents an asynchrounous (induction) generator with no external connection to the rotor windings, e.g squirel-cage induction machine. Model Name genAsync Description Asynchronous generator model Parameters: Parameter Name Bus number Unit ID MVAbase kVbase Rs Xls Xs Xp Xpp Tpo Tppo H (note 2) Usual Units MVA kV p.u. p.u. p.u. p.u. p.u. sec. sec. sec. D (note 3) S1 (note4) S12 (note 4) none none none CIM Units?? Typical Value MVA kV sec. sec. none none none 0.005 0.15 1.8 0.5 0.2 5.0 0.03 3.0 0.0 0.02 0.12 Description Terminal bus number in power flow case Motor (generator) ID in power flow case MVA base for p.u. values kV base for p.u. values Stator resistance (>= 0.) Stator leakage reactance (> 0.) Synchronous reactance (>= Xp) Transient reactance (unsaturated) (> =Xpp) Sub-transient reactance (unsaturated) (> Xl) Transient rotor time constant (> Tppo) Sub-transient rotor time constant (> 0.) Inertia constant of motor and mechanical load (> 0.) Damping factor Saturation factor at rated term. voltage (>= 0.) Saturation factor at 120% of rated term. voltage (>=S1) 1. Generator parameters such as Xls, Xs, etc. are actually used as inductances (L) in the model, but are commonly referred to as reactances since, at nominal frequency, the per unit values are the same. However, some references (e.g. PSLF User Manual) use the symbol L instead of X. Also, the “p” in the parameter names is a substitution for a “prime” in the usual notation, e.g. Xpp refers to X”. 2. H is the stored energy in the rotating mass of the generator plus all other elements (turbine, exciter) on the same shaft and has units of MW-sec. Conventional units are per unit on the generator MVA base, usually expressed as MW-sec./MVA or just sec. (since MW and MVA are equivalent units). 3. D has units of power/speed but is regarded as a dimensionless factor resulting from linearization of an exponential relationship between speed and power: P = Po (ω)D . This value is often zero when the source of damping torques (damper windings, load damping effects, etc.) are modeling in detail. [ref] 4. Saturation factors (S1, S12) are defined by S(E1) and S(E2) in Figure genSync1 above. Page 28 Model Equations: The mechanical equations for the motorAsync model can be represented by the following block diagram: d Pmech + n Σ n/d 1. Te _ Tm + 1 2Hs Σ + Σ + ∆ω ω speed slip _ D Figure genAsync1 Asynchronous Generator Mechanical Equation Block Diagram All variables are per unit on motor MVA base except angle, which is in radians. ωo is the system synchronous frequency in radians per second, e.g. 377. for 60Hz. systems. The electrical equations of the genAsync model are based on the following equivalent circuit diagram for the direct and quadrature axes, with two equivalent rotor windings in each axis: Rs d axis Xls Rr1 Rr2 Xlr1 Xlr2 Xm q axis – same as d -axis Figure genAsync2 Asynchronous Generator Equivalent Circuit In each axis, the branches represent the stator leakage reactance (Xls) and resistance (Rs), the magnetizing reactance (Xm), and the resistance and leakage reactance of equivalent windings (Rr1, Xlr1, etc.) on the rotor. The relationships between the equivalent circuit parameters and the standard model parameters are as follows: Page 29 Xd = Xm + Xls Xp = Xls + Xm * Xlr1 / (Xm + Xlr1) Xpp = Xls + Xm * Xlr1* Xlr2 / (Xm * Xlr1 + Xm * Xlr2 + Xlr1 * Xlr2) Tpo = (Xm + Xlr1) / (wo * Rr1) Tppo = (Xm * Xlr1 + Xm * Xlr2 + Xlr1 * Xlr2) / (wo * Rr2 * (Xm + Xlr1) If Xpp = Xp, a single cage (one equivalent rotor winding per axis) is modeled. CIM Model Type genAsync PSLF Model genind or motor1 PSS/E Model CIMTR1 CIMTR3 DigSilent Model ElmAsm Eurostag Model A specific block diagram for an asynchronous generator model is not shown. There will be variations in modeling among the application programs which should not materially affect the results in the stability analysis time scale. (ref Krause book/papers) Page 30 Large Synchronous Motor Models Large industrial motors or groups of similar motors may be represented by individual motor models (synchronous or asynchronous) which are represented as generators with negative Pgen in the static (power flow) data. Model Interconnections Standard interconnection of synchronous motor models with other models are shown in Figure 7-1 and listed in Table 7-1. Eterm Efd Excitation System E”d, E”q* Ifd Synchronous Motor speed Mechanical Load angle Network Equations Id, Iq* Pmech * Network interface variables may differ among application programs Synchronous Motor Interconnection Variables The interconnection with the electrical network equations may differ among application programs. The program only needs to know the terminal bus and generator ID to establish the correct interconnection. Synchronous Motor Interconnection Variables Model Type Inputs: Name Efd (note 1) Pmech Page 31 Motor Units p.u. p.u. Description Field voltage on base of Ifag * Rfd (field resistance) Mechanical shaft power drawn by mechanical load Source Exciter Mech. Load Outputs: Name Speed Angle Eppd Eppq Ifd (note 1) Units p.u. radians p.u. p.u. p.u. Description Motor (electrical) speed Motor rotor angle relative to synchronously-rotating reference frame Direct-axis subtransient voltage Quadrature-axis subtransient voltage Field current on Ifag base The following variables may be calculated in the motor model or in the network solution depending on the particular application program: Pgen p.u. Electrical power Qgen p.u. Reactive power Eterm p.u. Terminal voltage Iterm p.u. Terminal current magnitude Initialization Inputs: Name Units Eterm busAngle Pgen Qgen p.u. radians MW MVAr Initialization Outputs: Name Units Speed p.u. Angle radians Efd (note 1) p.u. Ifd (note 1) p.u. Pmech p.u. Description Terminal voltage magnitude Terminal voltage angle relative to system reference Electrical power Reactive power Source Power Flow Power Flow Power Flow Power Flow Description Motor (electrical) speed Motor rotor angle relative to synchronously-rotating reference frame Field voltage on base of Ifag * Rfd (field resistance) Field current on Ifag base (= Efd initially) Mechanical shaft power drawn by mechanical load Notes: 1. The interface between the motor model and the network algebraic equations is application dependent. The variables used for this interface do not need to be specified since they are internal to the application program and will not be used by other models, e.g. user-written models. 2. If no exciter model is present for a unit, the field voltage (Efd) should be held constant at the initial value. 3. If no mechanical load model is present for a unit, the motor mechanical power (Pmech) should be held constant at the initial value. Page 32 motorSync - Synchronous Motor Model A single standard synchronous motor model is defined for the CIM, with several variations indicated by the “model type” attribute. This model can be used for all types of synchronous machines (salient pole, solid iron rotor). All types of the motorSync model use a subset of the same data parameters and input/output variables The input parameters are shown in the following table: Model Name motorSync Description Synchronous motor model with several variations Parameters: Parameter Name Bus number Unit ID Model Type MVAbase kVbase Ra Xl Xd Xpdv Usual Units CIM Units?? Typical Value None MVA kV p.u. p.u. p.u. p.u. Xppdv p.u. 0.2 Xq Xpq Xppq Tpdo Tppdo Tpqo Tppqo H (note 2) p.u. p.u. p.u. sec. sec. sec. sec. sec. 1.6 0.3 0.2 5.0 0.03 0.5 0.03 3.0 D (note 3) S1 (note4) S12 (note 4) none none none None MVA kV 0.005 0.15 1.8 0.5 sec. sec. sec. sec. none none none 0.0 0.02 0.12 Description Terminal bus number in power flow case Motor (generator) ID in power flow case See table below MVA base for p.u. values kV base for p.u. values Stator resistance (>= 0.) Stator leakage reactance (> 0.) D-axis synchronous reactance (>= Xpdv) D-axis transient reactance (unsaturated) (> =X”dv) D-axis sub-transient reactance (unsaturated) (> Xl) Q-axis synchronous reactance (> =Xpq) Q-axis transient reactance (> =Xppq) Q-axis sub-transient reactance (> Xl) D-axis transient rotor time constant (> Tppdo) D-axis sub-transient rotor time constant (> 0.) Q-axis transient rotor time constant (> Tppqo) Q-axis sub-transient rotor time constant (> 0.) Inertia constant of motor and mechanical load (> 0.) Damping factor Saturation factor at rated term. voltage (>= 0.) Saturation factor at 120% of rated term. voltage (>=S1) 1. Motor parameters such as Xl, Xd, etc. are actually used as inductances (L) in the models, but are commonly referred to as reactances since, at nominal frequency, the per unit values are the same. However, some references (e.g. PSLF User Manual) use the symbol L instead of X. Also, the “p” in the parameter names is a substitution for a “prime” in the usual notation, e.g. Xppd refers to X”d. Page 33 2. H is the stored energy in the rotating mass of the motor plus its mechanical load and has units of MW-sec. Conventional units are per unit on the motor MVA base, usually expressed as MW-sec./MVA or just sec. (since MW and MVA are equivalent units). 3. D has units of power/speed but is regarded as a dimensionless factor resulting from linearization of an exponential relationship between speed and power: P = Po (ω)D . This value is often zero when the source of damping torques (damper windings, load damping effects, etc.) are modeling in detail. [ref] 4. Saturation factors (S1, S12) are defined by S(E1) and S(E2) in Figure 7-2 OPEN CIRCUIT VOLTAGE AIR GAP LINE OPEN CIRCUIT MAGNETIZATION CURVE E2 OBi - OAi S(E) = --------------OAi E1 For generators E1 = 1.0 E2 = 1.2 For Exciters E1, E2 are parameters 0 A1 B1 A2 B2 MAGNETIZING CURRENT Figure 7-2 Synchronous Motor Saturation Parameters Note: The quantity OA1 in amperes is normally called Ifag -- Field current at rated voltage, open circuit on the air gap (no saturation) line. Page 34 Model Equations: The mechanical equations for all variatons of the motorSync model are the same and can be represented by the following block diagram: 1. Te Pmech d n Σ n/d + Tm _ Σ 1 2Hs + + ∆ω Σ ω speed ωo s angle + D Figure 7-2 Synchronous Motor Mechanical Equation Block Diagram All variables are per unit on motor MVA base except angle, which is in radians. ωo is the system synchronous frequency in radians per second, e.g. 377. for 60Hz. systems. The electrical equations for all variations of the motorSync model are based on the following equivalent circuit diagram for the direct and quadrature axes: Page 35 Ra Xl Rfd Xfd Rkd efd Xad d axis + Xkd Ra Xl R1q X1q R2q q axis Xaq X2q Figure 7-3 Synchronous Motor Equivalent Circuit In each axis, the branches represent the stator leakage reactance (Xl) and resistance (Ra), the magnetizing reactance (Xad, Xaq), the physical field winding (Rfd, Xfd, efd) on the rotor, and equivalent windings for eddy current flow in the rotor iron. This equivalent circuit makes the assumption of equal mutual inductance among all of the windings (rotor to stator, rotor d to rotor q). Models based on unequal mutual inductance are not normally used for stability analysis. The definition of d and q axis variables is based on the following phasor diagram (counterclockwise rotation), for the case of a motor consuming P and overexcited (generating Q): Page 36 bus angle Et It (Ra + jX”) Network Reference E” It rotor angle j It ( Xq-X”) q axis d axis Figure 7-4 Synchronous Motor Phasor Diagram The relationships between the equivalent circuit parameters and the standard model parameters are as follows: Xd = Xad + Xl X’d = Xl + Xad * Xfd / (Xad + Xfd) X”d = Xl + Xad * Xfd* Xkd / (Xad * Xfd + Xad * Xkd + Xfd * Xkd) T’do = (Xad + Xfd) / (wo * Rfd) T”do = (Xad * Xfd + Xad * Xkd + Xfd * Xkd) / (wo * Rkd * (Xad + Xfd) Xq = Xaq + Xl X’q = Xl + Xaq * X1q / (Xaq+ X1q) X”q = Xl + Xaq * X1q* X2q / (Xaq * X1q + Xaq * X2q + X1q * X2q) T’qo = (Xaq + X1q) / (wo * R1q) T”qo = (Xaq * X1q + Xaq * X2q + X1q * X2q)/ (wo * R2q * (Xaq + X1q) The several variations of the motorSync model described on the following pages differ in the following ways: • The number of equivalent windings that are included • The way in which saturation is incorporated into the model. • Whether or not “subtransient saliency” (Xppq ≠ Xppdv) is represented. Variations of the motorSync model are identified by the “model type” attribute as shown in the table below, together with the corresponding model names in each application program. Each model type is described in detail on the following pages. CIM Page 37 PSLF PSS/E DigSilent Eurostag Model Type RoundRotor SalientPole Model genrou gensal Model GENROU GENSAL Model ElmSym ElmSym Model Note: It is not necessary for each program to have separate models for each of the model types. The same model can often be used for several types by alternative logic within the model. Also, differences in saturation representation may not result in significant model performance differences so model substitutions are often acceptable. motorSync - RoundRotor Type The complete equivalent circuit is used with two rotor windings in each axis. Notes: • • • Xppq is assumed to be equal to Xppd (no subtransient saliency) Saturation is modeled in both the d and q axes as shown in the block diagram The following input parameters are not used: Xppq Block Diagram: Page 38 iq Efd Σ 1 sT' do 1 sT' ' do Σ ψkd X' d − X' ' d ( X' d − Xl) * *2 Σ Ifd ω X' ' d − Xl X' d − Xl ψfd X' d − X' ' d X' d − Xl Σ X'd-Xl ψ"d Ra Eq Π Σ X''d d-AXIS id Σ Xd-X'd ψ" = sqrt(ψ"d2+ψ"d2) ψ" d Se ψ"q Xq − Xl Xd − Xl Xq-X'q Σ Σ X' q − X' ' q ( X' q − Xl) * *2 ψ1q Σ 1 sT' qo Σ 1 sT' ' qo iq q-AXIS X'q-Xl ψ2q X' q − X' q X' q − Xl X' ' q − Xl X' q − Xl X''q ψ"q Σ Π Σ Ed ω Ra id Figure 7-5 motorSync – RoundRotor Type Model Block Diagram Page 39 motorSync - Salient Pole Type The d-axis equivalent circuit is the same as for the RoundRotor type. The q-axis has only one equivalent rotor winding, which may be labeled as transient (Xpq) or subtransient (Xppq) – Xpq is used for the CIM description. Notes: • • • Xppq (=Xpq) is assumed to be equal to Xppdv (no subtransient saliency) Saturation is modeled in the d axis only as shown in the block diagram The following input parameters are not used: Xpq, Xppq, Tppqo Block Diagram: L"d - Ll L'd - Ll Efd 1 sT' do Pfd 1 sT' ' do Pkd P"d L'd - L"d L'd - Ll d-AXIS L'd - L"d L'd - Ll (L'd - Ll) **2 SePfd Ld - L'd id Lad ifd 1 sT' ' qo P"q Pkq q-AXIS Lq - Lq” iq Figure 7-6 motorSync – SalientPole Type Model Block Diagram Page 40 Large Asynchronous Motor Models The standard interconnection variables between an asynchronous motor model and other models are shown in the following figure and table: E”d, E”q* speed Mechanical Load Network Equations Asynchronous Motor Id, Iq* Pmech * Network interface variables may differ among application programs Asynchronous Motor Interconnection Variables The interconnection with the electrical network equations may differ among application programs. The program only needs to know the terminal bus and generator ID to establish the correct interconnection. Asynchronous Motor Interconnection Variables Model Type Inputs: Name Asynchronous Motor Units Pmech p.u. Outputs: Name Speed Eppd Eppq Units p.u. p.u. p.u. Description Mechanical shaft power of motor load Source Mech. Load Description Motor (electrical) speed Direct-axis subtransient voltage Quadrature-axis subtransient voltage The following variables may be calculated in the motor model or in the network solution depending on the particular application program: Pe p.u. Electrical power Qe p.u. Reactive power Eterm p.u. Terminal voltage Iterm p.u. Terminal current magnitude Page 41 Initialization Inputs: Name Units Eterm busAngle Pgen Qgen p.u. radians MW MVAr Description Terminal voltage magnitude Terminal voltage angle relative to system reference Electrical power Reactive power Source Power Flow Power Flow Power Flow Power Flow Initialization Outputs: Name Units Description Speed p.u. Motor (electrical) speed (= 1.0 initially) Pmech p.u. Mechanical shaft power to the generator Notes: 1. Input/output variable units should be kept in per unit. Attempts to convert to engineering units would be confusing. Since these variable are not directly attributes of CIM classes, this should not conflict with CIM standards. 2. The interface between the motor model and the network algebraic equations is application dependent. The variables used for this interface do not need to be specified since they are internal to the application program and will not be used by other models, e.g. user-written models. 3. If no Mechanical Load model is present for a unit, the motor mechanical power (Pmech) should be held constant at the initial value. motorAsync - Asynchronous Motor Model The motorAsynch model represents an asynchrounous (induction) motor with no external connection to the rotor windings, e.g squirel-cage induction motor. Model Name motorAsync Description Asynchronous motor model Parameters: Parameter Name Bus number Unit ID MVAbase kVbase Rs Xls Xs Xp Page 42 Usual Units MVA kV p.u. p.u. p.u. p.u. CIM Units?? Typical Value MVA kV 0.005 0.15 1.8 0.5 Description Terminal bus number in power flow case Motor (generator) ID in power flow case MVA base for p.u. values kV base for p.u. values Stator resistance (>= 0.) Stator leakage reactance (> 0.) Synchronous reactance (>= Xp) Transient reactance (unsaturated) (> =Xpp) Xpp Tpo Tppo H (note 2) p.u. sec. sec. sec. sec. sec. 0.2 5.0 0.03 3.0 D (note 3) S1 (note4) S12 (note 4) none none none none none none 0.0 0.02 0.12 Sub-transient reactance (unsaturated) (> Xl) Transient rotor time constant (> Tppo) Sub-transient rotor time constant (> 0.) Inertia constant of motor and mechanical load (> 0.) Damping factor Saturation factor at rated term. voltage (>= 0.) Saturation factor at 120% of rated term. voltage (>=S1) 1. Motor parameters such as Xl, Xs, etc. are actually used as inductances (L) in the model, but are commonly referred to as reactances since, at nominal frequency, the per unit values are the same. However, some references (e.g. PSLF User Manual) use the symbol L instead of X. Also, the “p” in the parameter names is a substitution for a “prime” in the usual notation, e.g. Xpp refers to X”. 2. H is the stored energy in the rotating mass of the motor plus its mechanical load and has units of MW-sec. Conventional units are per unit on the motor MVA base, usually expressed as MW-sec./MVA or just sec. (since MW and MVA are equivalent units). 3. D has units of power/speed but is regarded as a dimensionless factor resulting from linearization of an exponential relationship between speed and power: P = Po (ω)D . This value is often zero when the source of damping torques (damper windings, load damping effects, etc.) are modeling in detail. [ref] 4. Saturation factors (S1, S12) are defined by S(E1) and S(E2) in Figure genSync1 above. Model Equations: The mechanical equations for the motorAsync model can be represented by the following block diagram: 1. Te Pmech d n Σ n/d + Tm _ Σ 1 2Hs + + ∆ω Σ ω speed slip + D Figure motorAsync1 Asynchronous Motor Mechanical Equation Block Diagram All variables are per unit on motor MVA base except angle, which is in radians. ωo is the system synchronous frequency in radians per second, e.g. 377. for 60Hz. systems. Page 43 The electrical equations of the motorAsync model are based on the following equivalent circuit diagram for the direct and quadrature axes, with two equivalent rotor windings in each axis: Xls Rs Rr1 Rr2 Xlr1 Xlr2 Xm d axis q axis – same as d -axis Figure motorAsync2 Asynchronous Motor Equivalent Circuit In each axis, the branches represent the stator leakage reactance (Xls) and resistance (Rs), the magnetizing reactance (Xm), and the equivalent windings (Rr1, Xlr1, etc.) on the rotor. The relationships between the equivalent circuit parameters and the standard model parameters are as follows: Xd = Xm + Xls Xp = Xls + Xm * Xlr1 / (Xm + Xlr1) Xpp = Xls + Xm * Xlr1* Xlr2 / (Xm * Xlr1 + Xm * Xlr2 + Xlr1 * Xlr2) Tpo = (Xm + Xlr1) / (wo * Rr1) Tppo = (Xm * Xlr1 + Xm * Xlr2 + Xlr1 * Xlr2) / (wo * Rr2 * (Xm + Xlr1) If Xpp = Xp, a single cage (one equivalent rotor winding per axis) is modeled. CIM Model Type motorAsync PSLF Model motor1 PSS/E Model CIMTR2 DigSilent Model ElmAsym Eurostag Model A specific block diagram for a motor model is not shown. There will be variations in modeling among the application programs which should not materially affect the results in the stability analysis time scale. Page 44 Voltage Compensation Models The voltage compensation model adjusts the terminal voltage feedback to the excitation system by adding a quantity that is proportional to the terminal current of the generator. It is linked to a specific generator by the Bus number and Unit ID Model Interconnections Standard interconnection of voltage compensation models with other models are shown in Figure B-1 and listed in Table B-1. Etr, Eti Network Itr, Iti Vc Voltage Compensation Excitation System Itr2, Iti2 Figure B-1 Voltage Compensation Model Standard Interconnections Table B-1 Voltage Compensation Model Standard Interconnections Inputs: Name Etr Eti Itr Iti Itr2 Iti2 Outputs: Name Vc Units p.u. p.u. p.u. p.u. p.u. p.u. Description Terminal voltage – real component Terminal voltage – imaginary component Terminal current – real component Terminal current – imaginary component Terminal current – real component – unit 2 Tterminal current – imaginary component – unit 2 Units p.u. Description Compensated terminal voltage Initialization Inputs: Name Units Etr p.u. Eti p.u. Itr p.u. Iti p.u. Itr2 p.u. Iti2 p.u. Initialization Outputs: Name Units Page 45 Description Terminal voltage – real component Terminal voltage – imaginary component Terminal current – real component Terminal current – imaginary component Terminal current – real component – unit 2 Tterminal current – imaginary component – unit 2 Description Source see note 1 see note 1 see note 1 see note 1 see note 2 see note 2 Source see note 1 see note 1 see note 1 see note 1 see note 2 see note 2 Vc p.u. Compensated terminal voltage Notes: 1. Source of the generator complex voltage components is application dependent. It may come from the generator or from the network equations. 2. Unit 2 is a second generator connected to the same terminal bus, usually the other unit of a cross-compound pair. These inputs are not used by all voltage compensation models. Page 46 vcompIEEE - IEEE Voltage Compensation Model Model Name vcompIEEE Description IEEE Voltage Compensation Model Inputs Etr, Eti, Itr, Iti Outputs: Vc Parameters: Parameter Name Bus number Unit ID Rcomp Xcomp Units Typical Value p.u. (gen. base) p.u. (gen. base) 0. -0.1 Description Terminal bus number in power flow case Generator ID in power flow case Compensating (compounding) resistance Compensating (compounding) reactance. Notes: . Equation: Vcomp = (Etr + jEti ) + (Rcomp + jXcomp ) * (Itr + jIti) CIM Model Type vcompIEEE PSLF Model Rcomp, Xcomp PSS/E Model IEEEVC COMP DigSilent Model drp_COMP Eurostag Model Notes: 1. PSLF does not have a separate Voltage Compensator model but permits the specification of Rcomp and Xcomp (with opposite sign convention) for each generator as part of its generator model data. Page 47 vcompCross – Cross-Compound Voltage Compensation Model Model Name vcompCross Description Voltage Compensation Model for Cross-Compound Generating Unit Inputs Etr, Eti, Itr, Iti, Itr2, Iti2 Outputs: Vc Parameters: Parameter Name Bus number Unit ID Rcomp Xcomp Rcomp2 Xcomp2 Units Typical Value p.u. (gen. base) p.u. (gen. base) p.u. (gen. base) p.u. (gen. base) 0. -0.1 0. -0.1 Description Terminal bus number in power flow case Generator ID in power flow case Self-Compensating (compounding) resistance Self-Compensating (compounding) reactance. Cross-Compensating (compounding) resistance Cross-Compensating (compounding) reactance. Notes: . Equation: Vcomp = (Etr + jEti ) + (Rcomp + jXcomp) * (Itr + jIti) + (Rcomp 2 + jXcomp2) * (Itr 2 + jIti2) CIM Model Type vcompCROSS PSLF Model none PSS/E Model COMPCC COMCC1 DigSilent Model Eurostag Model Notes: 1. Equation is based on convention in IEEE Std 421.5-2005. PSS/E model uses a different convention which can be translated to/from CIM equation coefficients. 2. PSLF does not currently have a standard model for cross compensation. Page 48 Excitation System Models The excitation system model provides the field voltage (Efd) for a synchronous machine model. It is linked to a specific generator by the Bus number and Unit ID. The data parameters are different for each excitation system model; the same parameter name may have different meaning in different models. Model Interconnections Standard interconnection of excitation system models with other models are shown in Figure C-1 and listed in Table C-1. VUE L OEL VOE L UEL Vs PSS Vref Efd Excitation System Voltage Compensator Vc Generator LadIfd Figure C-1 Excitation System Model Standard Interconnections Table C-1 Excitation System Model Standard Interconnections Inputs: Name Vc Vref Ifd Vs Voel Vuel Page 49 Units p.u. p.u. p.u. p.u. p.u. p.u. Description Compensated generator terminal voltage Voltage reference Generator field current Power system stabilizer (PSS) output Overexcitation limiter output Underexcitation limiter output Source see note 1 see note 2 Generator PSS OEL UEL Outputs: Name Efd Units p.u. Initialization Inputs: Name Units Efd p.u. Ifd p.u. Vc p.u. Initialization Outputs: Name Units Vref p.u. Vs p.u. Voel p.u. Vuel p.u. Description Generator field voltage Description Genator field voltage Generator field current Compensated generator terminal voltage Source Generator Generator Compensator Description Voltage Reference Power system stabilizer (PSS) output – initilialized to zero Overexcitation limiter output – initialized to large negative value Underexcitation limiter output – initialized to large positive value Notes: 1. If a voltage compensation model is present, it is the source of Vc. If not, Vc = Eterm from the generator model. (Note: PSS/E and PSLF handle compensation differently. In PSS/E, the compensator is a separate model, which may or may not be present. In PSLF, the compensating (compounding) impedance values (Rcomp, Xcomp) are included in the generator data. For CIM, separate compensating model is recommended.) 2. Vref may be modified by a user-written model. References Most of the standard excitation system models are based on the 2005 version of the IEEE standard 421.5 “IEEE Recommended Practice for Excitation System Modeling for Power System Stability Studies”. Earlier versions of this standard in 1992, 1980, and 1968 are also referenced. Nearly all of the models described in these earlier versions can be adequately represented by models in the 2005 standard. Therefore, separate CIM standard models are not included for those earlier versions of the models. Legacy models in PSLF and PSS/E based on the earlier versions are still used in many databases but can translated into the new versions without loss of accuracy. Page 50 excAC1A - IEEE AC1A Model Model Name excAC1A Description IEEE (1992/2005) AC1A Model Parameters: Parameter Name Bus number Unit ID Tr Tb Tc Ka Ta Vamax Vamin Te Kf Tf Kc Kd Ke E1 S(E1) E2 S(E2) Vrmax Vrmin Units sec. sec. sec. p.u. sec. p.u. p.u. sec. p.u. sec. p.u. p.u. p.u. p.u. none p.u. none p.u. p.u. Typical Value 0.0 0.0 0.0 400.0 0.02 14.5 -14.5 0.8 0.03 1.0 0.20 0.38 1.0 4.18 0.10 3.14 0.03 6.03 -5.43 Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant (>= 0.) TGR lag time constant (>= 0.) TGR lead time constant AVR gain (> 0.) AVR time constant (> 0.) Maximum AVR output (> 0.) Minimum AVR output (< 0.) Exciter time constant (> 0.) Rate feedback gain (>= 0.) Rate feedback time constant (> 0.) Rectifier regulation factor (>= 0.) Exciter internal reactance (>= 0.) Exciter field resistance constant Field voltage value 1 (note d) (> 0.) Saturation factor at E1 (note d) (>= 0.) Field voltage value 2. (note d) (> 0.) Saturation factor at E2 (note d) (>= 0.) Maximum exciter control signal (> 0.) Minimum exciter control signal (< 0.) Notes: a) For modeling alternator-rectifier excitation system with non-controlled rectifiers and feedback from exciter field current, e.g. Westinghouse Brushless system. b) Ka, Ta, Te, Tf must be non-zero. If Tr or Tb are zero, the respective blocks are bypassed. c) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate feedback, set Kf = 0. d) Saturation parameters are consistent with the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower. Page 51 Block Diagram: Vre f Vc 1 + sTr - Σ - Vrm a x Vam ax + + 1 V OEL V U EL Vs 1 + sTc Ka 1 + sTb 1+ sTa Va HV Gate LV Gate Vr + sTe - Π Efd Fex V r m in V a m in Ve 1 Σ 0 F( I n ) Vf In K e + Se ( Ve ) Vfe sKf 1+ sTf Kc Ifd / Ve + Σ + Kd Ifd Model Compatibility: CIM Model excAC1A PSLF Model esac1a exac1* PSS/E Model ESAC1A EXAC1* IEEX2A* IEET1A* DigSilent Model vco_ESAC1A Eurostag Model vco_IEET1A* * These models can be represented by excAC1A by setting specific parameters to zero or large values. Page 52 excAC2A - IEEE AC2A Model Model Name excAC2A Description IEEE (1992/2005) AC2A Model (ref) Parameters: Parameter Name Bus number Unit ID Tr Tb Tc Ka Ta Vamax Vamin Kb Vrmax Vrmin Te Vfemax Kh Kf Tf Kc Kd Ke E1 S(E1) E2 S(E2) Units sec. sec. sec. p.u. sec. p.u. p.u. p.u. p.u. p.u. sec. p.u. p.u. p.u. sec. p.u. p.u. p.u. p.u. none p.u. none Typical Value 0.0 0.0 0.0 400.0 0.01 8.0 -8.0 25.0 105.0 -95.0 0.6 4.4 1.0 0.03 1.0 0.28 0.35 1.0 4.4 0.037 3.3 0.012 Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant (>= 0.) TGR lag time constant (>= 0.) TGR lead time constant AVR gain (> 0.) AVR time constant (> 0.) Maximum AVR output (> 0.) Minimum AVR output (< 0.) Exciter field current controller gain (> 0.) Maximum exciter control signal (> 0.) Minimum exciter control signal (< 0.) Exciter time constant (> 0.) Exciter field current limit parameter (>= 0.) Exciter field current feedback gain (>= 0.) Rate feedback gain (>= 0.) Rate feedback time constant (> 0.) Rectifier regulation factor (>= 0.) Exciter internal reactance (>= 0.) Exciter field resistance constant Field voltage value 1 (note d) (> 0.) Saturation factor at E1 (note d) (>= 0.) Field voltage value 2. (note d) (> 0.) Saturation factor at E2 (note d) (>= 0.) Notes: a) For modeling high initial-response alternator-rectifier excitation system with non-controlled rectifiers and feedback from exciter field current, e.g. Westinghouse HIR Brushless system. b) Ka, Kb, Ta, Te, Tf must be non-zero. If Tr or Tb are zero, the respective blocks are bypassed. c) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate feedback, set Kf = 0. Page 53 d) Saturation parameters are consistent with the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower. . e) The upper limit on Ve represents the effect of the field current limiter. If Vfemax is zero, this limit will not be enforced. The real system, the limiter is implemented by a low value gate just before Kb. The input to this LV gate is Kl * (Vlr – Vfe). If the values of Kl and Vlr are known, Vfemax can be calculated as Vlr*Kl*Kb / (1 + Kl*Kb). Block Diagram: Vref Vc Vs + + 1 1 + sTr - Ka Va 1+ sTa + 1 + sTc Σ 1 + sTb - Va m in Kb Σ Vf e m a x - Kd I f d K e + Se ( Ve ) VOEL V U EL] Va m a x Vr m a x HV Gate LV Gate + Vh Vr 1 Σ - Π Ef d Fex 0 Vr m in Vf Ve sTe F( I n ) Kh In Ke +Se (Ve) Vf e sKf 1+ sTf Kc Ifd / Ve + Σ + Kd Ifd Model Compatibility: CIM Model excAC2A PSLF Model esac2a exac2* PSS/E Model ESAC2A EXAC2* DigSilent Model vco_ESAC2A vco_EXAC2 Eurostag Model * exac2a/EXAC2A are based on the 1981 IEEE standard. They can be converted to excAC2A by computing Vfemax parameter from Vlr, Kl as described in note e above. Page 54 excAC3A - IEEE AC3A Model Model Name excAC3A Description IEEE (1992/2005) AC3A Model (ref) Parameters: Parameter Name Bus number Unit ID Tr Tb Tc Ka Ta Vamax Vamin Te Vemin Kr Kf Tf Kn Efdn Kc Kd Ke Vfemax E1 S(E1) E2 S(E2) Units sec. sec. sec. p.u. sec. p.u. p.u. p.u. p.u. p.u. sec. p.u. p.u. p.u. sec. p.u. p.u. p.u. p.u. none p.u. none Typical Value 0.0 0.0 0.0 45.62 0.013 1.0 -0.95 1.17 0.84 3.77 0.143 1.0 0.05 2.36 0.104 0.499 1.0 16 6.24 1.143 4.68 0.1 Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant (>= 0.) TGR lag time constant (>= 0.) TGR lead time constant AVR gain (> 0.) AVR time constant (> 0.) Maximum AVR output (> 0.) Minimum AVR output (< 0.) Exciter time constant (> 0.) Minimum field voltage limit (<= 0.) Field self-excitation feedback gain (> 0.) Low level rate feedback gain (>= 0.) Rate feedback time constant (> 0.) High level rate feedback gain (>= 0.) Rate feedback gain break level (> 0.) Rectifier regulation factor (>= 0.) Exciter internal reactance (>= 0.) Exciter field resistance constant Exciter field current limit parameter (>= 0.) Field voltage value 1 (note d) (> 0.) Saturation factor at E1 (note d) (>= 0.) Field voltage value 2. (note d) (> 0.) Saturation factor at E2 (note d) (>= 0.) Notes: a) For modeling field-controlled alternator-rectifier excitation system with non-controlled, e.g. GE Alterrex systems with static voltage regulators. b) Ka, Kr, Ta, Te, Tf must be non-zero. If Tr or Tb are zero, the respective blocks are bypassed. c) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate feedback, set Kf = Kn = 0. Page 55 d) Saturation parameters are consistent with the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower. e) The upper limit on Ve is an approximate represention of the effect of the maximum field current limiter. If Vfemax is zero, this limit will not be enforced. The lower limit (Vemin) on Ve is an approximate representation of the minimum field voltage limiter. If these limiters are specified in terms of their basic parameters (Kl1, Kfa, Vlv), the exac3a model should be used. Block Diagram: Kr Vr e f Vc Vfem ax - Kd Ifd Ke + Se ( V e ) Vam ax V U EL + 1 1 + sTr - 1 + sTc Σ 1 + sTb HV G a te Ka Σ + - + Vf Vs 1+ sTa X Va Vr + 1 Σ sTe - Ve Π Efd Fex Va m in V e m in F( I n ) Vfe In s 1+ sTf Ke+Se (Ve) Kc I f d / Ve + Σ + Kd Vn Ifd Kn Vn Kf Efdn Efd Model Compatibility: CIM Model excAC3A PSLF Model esac3a exac3* exac3a* PSS/E Model ESAC3A EXAC3* DigSilent Model vco_ESAC3A Eurostag Model vco_EXAC3A * exac3/EXAC3 are based on the 1981 IEEE standard and represent the exciter limit differently. Exac3a represents the exciter limit differently from either exac3 or esac3a. They may be convertible to excAC3A by computing Vfemax parameter from other model parameters. Page 56 excAC4A - IEEE AC4A Model Model Name excAC4A Description IEEE (1992/2005) AC4A Model (ref) Parameters: Parameter Name Bus number Unit ID Tr Vimax Vimin Tc Tb Ka Ta Vrmax Vrmin Kc Units sec. p.u. p.u. sec. sec. p.u. sec. p.u. p.u. p.u. Typical Value 0.0 10.0 -10.0 1.0 10.0 100.0 0.02 5.64 -4.53 0.0 Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant (>= 0.) Maximum error signal ( > 0.) Minimum error signal (< 0.) Lead time constant Lag time constant (>= 0.) Gain (> 0.) Time constant (> 0.) Maximum controller output (> 0.) Minimum controller output (< 0.) Excitation system regulation (>= 0.) Notes: a) This model can be used to represent controlled rectifier systems in which the excitation power is provided by a voltage-controlled source such as a shaft driven alternator with its own voltage regulator. The voltage droop of the a.c. excitation power source, if any, and the regulation of the rectifier are approximated by the parameter, Kc. Do not use this model to represent "busfed" excitation systems. b) Ka and Ta must be non-zero. If Tr or Tb is zero, the respective block is bypassed. Block Diagram: Vr e f Vc + 1 1 + sT r S0 - 1 + sT b + Model Compatibility: Page 57 1 + sT c Σ Vs Vuel V im a x V im in Vr m a x - Kc Ifd HV gate Ka Efd 1 + sT a V r m in - K c I f d CIM Model excAC4A Page 58 PSLF Model esac4a exac4 PSS/E Model ESAC4A EXAC4 DigSilent Model vco_ESAC4A Eurostag Model excAC5A - IEEE AC5A Model Model Name excAC5A Description IEEE (1992/2005) AC5A Model (ref) Parameters: Parameter Name Bus number Unit ID Tr Ka Ta Vrmax Vrmin Ke Te Kf Tf1 Tf2 Tf3 E1 Se(E1) E2 Se(E2) Units sec. p.u. sec. sec. sec. p.u. sec. p.u. sec. sec. sec. p.u. none p.u. none Typical Value 0.0 400.0 0.02 7.3 -7.3 1.0 0.8 0.03 1.0 0.8 0.0 5.6 0.86 4.2 0.5 Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant (>= 0.) Gain (> 0.) Time constant (> 0.) Maximum controller output (> 0.) Minimum controller output (< 0.) Exciter field resistance line slope Exciter time constant, sec. (> 0.) Rate feedback gain (>= 0.) Rate feedback lag time constant (> 0.) Rate feedback lag time constant (>= 0.) Rate feedback lead time constant Field voltage value 1 (note c) (> 0.) Saturation factor at E1 (note c) (>= 0.) Field voltage value 2. (note c) (> 0.) Saturation factor at E2 (note c) (>= 0.) Notes: a) Simplified model of a brushless, rotating rectifier excitation system. b) Ka, Ta, Te, Tf1 must be greater than zero. Tr, Tf1, Tf2 may be zero. If Tr is zero, the block is bypassed. c) Saturation parameters are given by the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower . Block Diagram: Page 59 Vref + Vc 1 1 + sTr − Vs + Σ − Vrmax Vr Ka 1 + sTa + Σ − 1 1 + sTe Efd Vrmin Se(Ve) + Ke sKf (1 + sTf 3) (1 + sTf1) (1 + sTf 2) Model Compatibility: CIM Model excAC5A PSLF Model esac5a exdc2* PSS/E Model ESAC5A IEEET2 IEEEX2* DigSilent Model vco_ESAC5A Eurostag Model * exdc2 and IEEEX2 have an extra (1+sTc) / (1+sTb) block before the Ka / (1+sTa) block. They can be converted to excAC5A if Tb = Tc or Tb = 0. Page 60 excAC6A - IEEE AC6A Model Model Name excAC6A Description IEEE (1992/2005) AC6A Model (ref) Parameters: Parameter Name Bus number Unit ID Tr Ka Ta Tk Tb Tc Vamax Vamin Vrmax Vrmin Te Kh Tj Th Vfelim Vhmax Kc Kd Ke E1 S(E1) E2 S(E2) Units sec. p.u. sec. sec. sec. sec. p.u. p.u. p.u. p.u. sec. p.u. sec. sec. p.u. p.u. p.u. p.u. p.u. p.u. none p.u. none Typical Value 0.02 536 0.086 0.18 9.0 3.0 75.0 -75.0 44.0 -36.0 1.0 92.0 0.02 0.08 19.0 75.0 0.173 1.91 1.6 5.55 0.044 7.4 0.214 Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant Gain (> 0.) Time constant (>= 0.) Lag time constant (>= 0.) Time constant (>= 0.) Lead time constant Maximum controller element output (> 0.) Minimum controller element output (< 0.) Maximum exciter control signal (> 0.) Minimum exciter control signal (< 0.) Exciter time constant (> 0.) Exciter field current limiter gain (>= 0.) Field current limiter time constant (>= 0.) Field current limiter time constant (> 0.) Exciter field current limit reference (> 0.) Maximum field current limiter signal (> 0.) Rectifier regulation factor (>= 0.) Exciter internal reactance (>= 0.) Exciter field resistance constant (note c) Field voltage value 1 (note c) (> 0.) Saturation factor at E1 (note c) (>= 0.) Field voltage value 2. (note c) (> 0.) Saturation factor at E2 (note c) (>= 0.) Notes: a) Ka, Te, Th must be non-zero. If Tr, Ta, Tb or Tc is zero, the respective block is bypassed. b) To disable the forward path gain reduction, set Tb = Tc = 0. This will also disable the nonwindup limits Vamax and Vamin. c) If Ke = 0., it is set during initialization to make Vr = 0. Page 61 d) Saturation parameters is given by the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower. Block Diagram: Vuel Vs Vc 1 + sTr + + 1 − Vt Vrmax Va m a x Ka (1 + sTk) Σ 1 + sTa + 1 + sTc Va 1 + sTb + Vr Σ + − Va m i n sTe − F(In) 0 Vhmax Se In Vil 1 + sTj Vh 1 + sTh + Σ Kh − 0 + Σ + + Σ + Ke Model Compatibility: Page 62 PSLF Model esac6a exac6a PSS/E Model ESAC6A Kc Ifd / Ve Vfe Vfelim Kd CIM Model excAC6A Efd Π Fex Vt Vrmin Vref Ve 1 Σ DigSilent Model vco_ESAC6A Eurostag Model Ifd excAC7B - IEEE AC7B Model Model Name excAC7B Description IEEE (2005) AC7B Model (ref) Parameters: Parameter Name Bus number Unit ID Tr Kpr Kir Kdr Tdr Vrmax Vrmin Kpa Kia Vamax Vamin Kp Kl Te Vfemax Vemin Ke Kc Kd Kf1 Kf2 Kf3 Tf E1 S(E1) E2 S(E2) Units sec. p.u. p.u. p.u. sec. p.u. p.u. p.u. p.u. p.u. p.u. p.u. p.u. sec. p.u. p.u. p.u. p.u. p.u. p.u. p.u. p.u. sec. p.u. none p.u. none Typical Value 0.0 3.89 3.89 0.0 0.0 6.74 -6.74 117.7 26.8 1.0 -0.95 12.08 10.0 3.0 15.2 0.0 1.0 0.13 1.14 0.194 0.0 0.0 1.0 6.67 1.951 5.0 0.156 Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant (>= 0.) Regulator proportional gain (> 0. if Kir = 0.) Regulator integral gain (>= 0.) Regulator derivative gain (>= 0.) Derivative gain washout time constant (>= 0.) Maximum regulator output (> 0.) Minimum regulator output (< 0.) Amplifier proportional gain (> 0. if Kia = 0.) Amplifier integral gain (>= 0.) Maximum amplifier output (> 0.) Minimum amplifier output (< 0.) Exciter field voltage source gain (> 0.) Exciter field voltage lower limit parameter Exciter time constant, sec. (> 0.) Exciter field current limit parameter (note e) Minimum exciter ouput voltage (<= 0.) Exciter field resistance constant Rectifier regulation factor (>= 0.) Exciter internal reactance (>= 0.) Field voltage feedback gain (>= 0.) Exciter field current feedback gain (>= 0.) Rate feedback gain (>= 0.) Rate feedback time constant (> 0.) Field voltage value 1 (note d) (> 0.) Saturation factor at E1 (note d) (>= 0.) Field voltage value 2. (note d) (> 0.) Saturation factor at E2 (note d) (>= 0.) Notes: a) For modeling alternator-rectifier excitation system with either stationary or rotating rectifiers with PID voltage regulator. Page 63 b) Te and Tf must be non-zero. If Tr or Tdr are zero, the respective blocks are bypassed. Kpa and Kpi must not be zero if their corresponding integral gains are zero. c) To disable the rate feedback, set Kf3 = 0. d) Saturation parameters are consistent with the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower. e) The upper limit on Ve represents the effect of the field current limiter. If Vfemax is zero, this limit will not be enforced. f) In the IEEE Std 421.5 – 2005 document, the 1. / sTe block in the block diagram below is shown as 1. / (1 + sTE), which is incorrect Block Diagram: Kp V t + Vc 1 1 + sTr Vs Vr e f Vu e l - + + Σ Kpr + - Kir s + s Kdr 1+ sTdr Vf e m a x - K d I f d K e + S e ( Ve ) Va m a x Vr m a x + Kpa + Σ - Kia s Va Vr Π + sTe - Σ F( I n ) Kf 2 In + Ke+Se(Ve ) Vfe s Kf 3 1+ sTf Σ + Kf 1 Model Compatibility: Page 64 PSLF Model esac7b Kc I f d / Ve + Kd CIM Model excAC7B Ef d V e m in Va m in + Π Fex - Kl V f e V r m in Vf Ve 1 Σ PSS/E Model ESAC7B DigSilent Model Eurostag Model Ifd excAC8B - IEEE AC8B Model Model Name excAC8B Description IEEE (2005) AC8B Model (ref) Parameters: Parameter Name Bus number Unit ID Tr Kpr sec. p.u. 0.0 80.0 Kir Kdr Tdr p.u. p.u. sec. 5.0 10.0 0.1 Vrmax Vrmin Ka Ta Te Vfemax Vemin Ke Kc Kd E1 S(E1) E2 S(E2) vtmult p.u. p.u. p.u. sec. sec. p.u. p.u. p.u. p.u. p.u. p.u. none p.u. none none 35.0 0.0 1. 0.0 1.2 6.0 0.0 1.0 0.55 1.1 6.5 0.3 9.0 3.0 0. Units Typical Value Description Terminal bus number in power flow case Generator ID in power flow case Voltage transducer time constant (>= 0.) Voltage Regulator Proportional Gain (> 0. if Kir = 0.) Voltage Regulator Integral Gain (>= 0.) Voltage Regulator Derivative Gain (>= 0.) Voltage Regulator Derivative Time Constant (> 0. if Kdr > 0.) Maximum controller output (> 0.) Minimum controller output (<= 0.) Amplifier gain (> 0.) Amplifier time constant (>= 0.) Exciter field time constant (> 0.) Exciter field current limit parameter (note d) Minimum exciter ouput voltage (<= 0.) Exciter field proportional constant Rectifier regulation factor (>= 0.) Exciter regulation factor (>= 0.) Field voltage value 1 (note c) (> 0.) Saturation factor at E1 (note c) (>= 0.) Field voltage value 2. (note c) (> 0.) Saturation factor at E2 (note c) (>= 0.) if not 0, multiply Vrmax and Vrmin by terminal voltage (note e) Notes: a) This model represents a PID voltage regulator with either a brushless exciter or dc exciter. For a dc exciter, Kc and Kd are set to zero. b) Te must be non-zero. If Tr is zero, the block is bypassed. If Ta is zero, the block is reduced to multiplication by Ka. If Tdr is zero, the output of the derivative block is set to zero. Kpr must not be zero if Kir is zero. Page 65 c) Saturation parameters are consistent with the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower. d) The upper limit on Ve represents the effect of the field current limiter. If Vfemax is zero, this limit will not be enforced. e) If vtmult is non-zero, the limits Vrmax and Vrmin are multiplied by the generator’s terminal voltage to represent a thyristor power stage fed from the generator terminals. This parameter is not in the IEEE standard model. Block Diagram: Vre f Kp r + Vc 1 1 + sTr + Kir Σ - s Σ + + + sKdr 1 + sTdr Vs Vfe m a x - Kd Ifd K e + S e ( Ve ) Vr m a x Ka 1 + sTa V r m in Vr + 1 sTe Σ - V emi n Ife Ve Π Efd Fex F (In) In Σ Ke + Se + + Kc Ifd Ve Ifd Kd Model Compatibility: CIM Model excAC8B PSLF Model esac8b PSS/E Model ESAC8B* DigSilent Model vco_ESAC8B Eurostag Model * As of rev. 30, ESAC8B in PSS/E did not have the parameters Kc, Kd, Vfemax, Vemin of the IEEE model. Therefore, it can represent a dc exciter but not an ac/rectifier exciter. Page 66 excDC1A - IEEE DC1A Model Model Name excDC1A Description IEEE (1992/2005) DC1A Model (ref) Parameters: Parameter Name Bus number Unit ID Tr Ka Ta Tb Tc Vrmax Vrmin Ke Te Kf Tf E1 S(E1) E2 S(E2) uelin sec. p.u. sec. sec. sec. p.u. p.u. p.u. sec. p.u. sec. p.u. none p.u. none none 0.0 40.0 0.1 0.0 0.0 1.0 -1.0 0.1 0.5 0.05 0.7 2.8 0.08 3.7 0.33 0 exclim none 0 Units Typical Value Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant (>= 0.) Gain (> 0.) Time constant (> 0.) Lag time constant (>= 0.) Lead time constant Maximum controller output (note d) Minimum controller output (< 0.) Exciter field resistance line slope (note c) Exciter time constant (> 0.) Rate feedback gain (>= 0.) Rate feedback time constant, sec. (> 0.) Field voltage value 1 (note e) (> 0.) Saturation factor at E1 (note e) (>= 0.) Field voltage value 2. (note e) (> 0.) Saturation factor at E2 (note e) (>= 0.) UEL input: if < 2, HV gate; if = 2, add to error signal If not 0, apply lower limit of 0. to exciter output (note f) Notes: a) Ka, Ta, and Te, must be greater than zero. If Tr, Tb or Tf are zero, the respective blocks are bypassed. b) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate feedback, set Kf = 0. c) If Ke is entered as zero, the model calculates an effective value of Ke such that the initial condition value of Vr is zero. The zero value of Ke is not changed. If Ke is entered as nonzero, its value is used directly, without change. Page 67 d) If Vrmax <= 0., an effective maximum control value of Vrmax is determined, such that the control signal, Vr, has the value Vrmax when the exciter output is equal to E2. e) Saturation parameters is given by the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower value if the input value of Vrmax > 0; else E2 must > E1. f) IEEE standard is ambiguous about lower limit on exciter output. If exclim is set non-zero, a lower limit of zero is applied to integrator output. Block Diagram: Vref Vc uel i n = 2 + Vs 1 + sTc 1 + sTb Σ − uel i n < 2 Vrm a x + + 1 1 + sTr V U EL HV G a te Ka 1 + sTa − Vr + Σ − V r m in Vf 1 sTe Efd (no te f) Se + Ke sKf 1 + sTf Model Compatibility: CIM Model excDC1A PSLF Model esdc1a exdc1* ieeet1* PSS/E Model ESDC1A IEEEX1* IEEET1* DigSilent Model vco_ESDC1A vco_IEEEX1 vco_IEEET1 Eurostag Model * These models are based on early versions of the IEEE standard and can be converted to the excDC1A model without loss of data. Page 68 excDC2A - IEEE DC2A Model Model Name excDC2A Description IEEE (1992/2005) DC2A Model (ref) Parameters: Parameter Name Bus number Unit ID Tr Ka Ta Tb Tc Vrmax Vrmin Ke Te Kf Tf E1 S(E1) E2 S(E2) uelin sec. p.u. sec. sec. sec. p.u. p.u. p.u. sec. p.u. sec. p.u. none p.u. none none 0.0 300.0 0.01 0.0 0.0 4.95 -4.9 1.0 1.33 0.1 0.675 3.05 0.279 2.29 0.117 0 exclim none 0 Units Typical Value Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant (>= 0.) Gain (> 0.) Time constant (> 0.) Lag time constant (>= 0.) Lead time constant Maximum controller output (note d) Minimum controller output (< 0.) Exciter field resistance line slope (note c) Exciter time constant (> 0.) Rate feedback gain (>= 0.) Rate feedback time constant, sec. (> 0.) Field voltage value 1 (note e) (> 0.) Saturation factor at E1 (note e) (>= 0.) Field voltage value 2. (note e) (> 0.) Saturation factor at E2 (note e) (>= 0.) UEL input: if < 2, HV gate; if = 2, add to error signal If not 0, apply lower limit of 0. to exciter output (note f) Notes: a) Ka, Ta, and Te, must be greater than zero. If Tr or Tb is zero, the respective block is bypassed. If Tf is zero, the rate feedback block is not used. b) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate feedback, set Kf = 0 or Tf = 0. c) If Ke is entered as zero, the model calculates an effective value of Ke such that the initial condition value of Vr is zero. The zero value of Ke is not changed. If Ke is entered as nonzero, its value is used directly, without change. Page 69 d) If Vrmax <= 0., an effective maximum control value of Vrmax is determined, such that the control signal, Vr, has the value Vrmax when the exciter output is equal to E2. e) Saturation parameters are given by the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower value if the input value of Vrmax > 0; else E2 must > E1. f) IEEE standard is ambiguous about lower limit on exciter output. If exclim is set non-zero, a lower limit of zero will be applied to integrator output. Block Diagram: Vref Vc uel i n = 2 + Vs 1 + sTc 1 + sTb Σ − uel i n < 2 Vt * Vrm a x + + 1 1 + sTr V U EL HV G a te Ka 1 + sTa Vr + − V t * V r m in Vf Σ − 1 sTe Efd (no te f) Se + Ke sKf 1 + sTf Model Compatibility: CIM Model excDC2A PSLF Model esdc2a exdc2a* PSS/E Model EXDC2A EXDC2* DigSilent Model Eurostag Model * These models are based on early versions of the IEEE standard and can be converted to the excDC2A model without loss of data. Page 70 excDC3A - IEEE DC3A Model Model Name excDC3A Description IEEE (1992/2005) DC3A Model (ref) Parameters: Parameter Name Bus number Unit ID Tr Trh Kv sec. sec. p.u. 0.0 20.0 0.05 Vrmax Vrmin Te Ke E1 S(E1) E2 S(E2) exclim p.u. p.u. sec. p.u. p.u. none p.u. none none 5.0 0.0 1.83 1.0 2.6 0.1 3.45 0.35 0 Units Typical Value Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant (>= 0.) Rheostat full range travel time (> 0.) Voltage error threshold min/max control action (> 0.) Maximum control element output (> 0.) Minimum control element output (<= 0.) Exciter field time constant (> 0.) Exciter field resistance line slope (note b) Field voltage value 1 (note c) (> 0.) Saturation factor at E1 (note c) (>= 0.) Field voltage value 2. (note c) (> 0.) Saturation factor at E2 (note c) (>= 0.) If not 0, apply lower limit of 0. to exciter output (note d) Notes: a) Kv, Trh and Te must be greater than zero. b) If Ke is entered as zero, the model calculates an effective value of Ke such that the initial condition value of Vr is zero. The zero value of Ke is not changed. If Ke is entered as nonzero, its value is used directly, without change. c) Saturation parameters are given by the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower. d) IEEE standard is ambiguous about lower limit on exciter output. If exclim is set non-zero, a lower limit of zero will be applied to integrator output. Block Diagram: Page 71 Vre f Vrmax Vc Kv + 1 1 + sTr − Σ Verr Vrmax −Vrmin s Kv Trh −Kv Vrmin If V err ≥ K v , Vr = Vr max If V err ≤ −K v , Vr = Vr min else Vr = Vrh Vx = Efd Se(Efd) Vx Vrh Vr − + Σ 1 Ke + STe (note d) Model Compatibility: CIM Model excDC3A PSLF Model esdc3a exdc4* PSS/E Model IEEEX4 DigSilent Model * exdc4 with it’s parameter Kr = 0 is the same as excDC3A Page 72 Eurostag Model Efd excDC4B - IEEE DC4B Model Model Name excDC4B Description IEEE (2005) DC4B Model Parameters: Parameter Name Bus number Unit ID Tr Ka Ta Kp Ki Kd Td Vrmax Vrmin Ke Te Kf Tf E1 S(E1) E2 S(E2) Vemin OELin sec. p.u. sec. p.u. p.u. p.u. sec. p.u. p.u. p.u. sec. p.u. sec. p.u. none p.u. none p.u. none 0.0 1.0 0.2 80 20 20 0.01 6.0 -2.7 1.0 0.8 0.0 0.0 1.75 0.08 2.33 0.27 0. 0 UELin none 0 Units Typical Value Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant (>= 0.) Gain (> 0.) Time constant (> 0.) Proportional gain (>= 0.) Integral gain (>= 0.) Derivative gain (>= 0.) Derivative time constant (> 0. If Kd > 0.) Maximum controller output (note d) Minimum controller output (<= 0.) Exciter field resistance line slope (note c) Exciter time constant (> 0.) Rate feedback gain (>= 0.) Rate feedback time constant (>= 0.) Field voltage value 1 (note e) (> 0.) Saturation factor at E1 (note e) (>= 0.) Field voltage value 2. (note e) (> 0.) Saturation factor at E2 (note e) (>= 0.) Exciter minimum output (<= 0.) OEL input: if < 2, LV gate; if = 2, subtract from error signal UEL input: if < 2, HV gate; if = 2, add to error signal Notes: a) Ka, Ta, and Te, must be greater than zero. If Tr is zero, the block is bypassed. If Td or Tf are zero, the respective blocks are not used. b) To disable the derivative path, set Kd = 0 or set Td = 0.. To disable the rate feedback, set Kf = 0. Page 73 c) If Ke is entered as zero, the model calculates an effective value of Ke such that the initial condition value of Vc is zero. The zero value of Ke is not changed. If Ke is entered as nonzero, its value is used directly, without change. d) If Vrmax <= 0., an effective maximum control value of Vrmax is determined, such that the control signal, Vc, has the value Vrmax when the exciter output is equal to E2. e) Saturation parameters are given by the IEEE saturation factor definition using the open circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value and the other the lower value if the input value of Vrmax > 0; else E2 must > E1. Block Diagram: oel i n = 2 uel i n = 2 Vref Vc 1 1 + sTr − + Vs [vsig] + Σ oel i n < 2 uel i n < 2 Vt Vrm a x / Ka − + V U EL V OEL Kpr + Kir s + s Kdr 1+ sTdr Vt Vrm a x HV G a te LV G a te Π Ka 1 + sTa − Vf Vr + Σ − V t V r m in V r m in / K a 1 sTe (note g) Se + Ke sKf 1 +S4sTf Model Compatibility: CIM Model excDC4B PSLF Model esdc4b ** Not in PSS/E as of rev. 30 Page 74 PSS/E Model ** DigSilent Model Eurostag Model Efd excST1A - IEEE ST1A Model Model Name excST1A Description IEEE (1992/2005) ST1A Model Parameters: Parameter Name Bus number Unit ID Tr Vimax Vimin Tc Tb Ka Ta Vrmax Vrmin Kc Kf Tf Tc1 Tb1 Vamax Vamin Ilr Klr UELin sec. p.u. p.u. sec. sec. p.u. sec. p.u. p.u. p.u. p.u. sec. sec. sec. p.u. p.u. p.u. p.u. none 0.0 999. -999. 1.0 10.0 190.0 .02 7.8 -6.7 0.05 0.0 1.0 0.0 0.0 999. -999. 0.0 0.0 0 PSSin none 0 Units Typical Value Description Terminal bus number in power flow case Generator ID in power flow case Voltage transducer time constant (>= 0.) Maximum error (> 0.) Minimum error (< 0.) Lead time constant Lag time constant (>= 0.) Gain (> 0.) Time constant (>= 0.) Excitation voltage upper limit (> 0.) Excitation voltage lower limit (< 0.) Excitation system regulation factor (>= 0.) Rate feedback gain (>= 0.) Rate feedback time constant (>= 0.) Lead time constant Lag time constant (>= 0.) Maximum control element output (> 0.) Minimum control element output (< 0.) Maximum field current (note b) Gain on field current limit (note b) = 2 – UEL input added to error signal = 1 – UEL input HV gate with error signal = -1 – UEL input HV gate with volt. reg. output = 0 – ignore UEL signal = 0 – PSS input (Vs) added to error signal ≠ 0 – PSS input (Vs) added to voltage regulator output Notes: a) This model can be used to represent a controlled-rectifier excitation system whose a.c. power source is a power transformer fed from the generator terminals. The voltage regulation of the excitation transformer and rectifier are approximated by the parameter Kc. Page 75 b) The field current limiter (Klr, Ilr) is optional. If Klr = 0., the limiter is not used. c) Ka and Ta must not be zero. If Ta, Tr, Tb, or Tb1 are zero, the corresponding block is bypassed. If Tf is zero, the output of the rate feedback block is zero. Block Diagram: V U EL Vs ps s i n = 0 Vc 1 1 + sTr − Vs Σ + V U EL ps sin ≠ 0 uel i n = 1 Vimax + + VU EL uel i n = 2 uel i n = - 1 Vt Vrm ax - Kc Ifd Vam a x HV Gate 1 + sTc 1 + sTb 1 + sTc1 1 + sTb1 Ka Va 1 + sTa − + + HV Gate Σ LV Gate V a m in Ef d Vt V r m in Vref Voel sKf + sTf Klr Σ + • − 0 I lr Model Compatibility: PSLF Model esst1a exst1* PSS/E Model ESST1A EXST1* DigSilent Model vco_ESST1A vco_EXST1 Eurostag Model * Based on earlier (1981) IEEE standard. Can be converted to excST1A. Page 76 • − Vimin CIM Model excST1A Ve lf d excST2A - IEEE ST2A Model Model Name excST2A Description IEEE (1992/2005) ST2A Model Parameters: Parameter Name Bus number Unit ID Tr Ka Ta Vrmax Vrmin Ke Te Kf Tf Kp Ki Kc Efdmax UELin Tb Tc Units sec. p.u. sec. p.u. p.u. p.u. sec. p.u. sec. p.u. p.u. p.u. p.u. none sec. sec. Typical Value 0.0 120.0 0.15 1.0 -1.0 1.0 0.5 0.05 0.7 4.88 8.0 1.82 99.0 0 0.0 0.0 Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant (>= 0.) Gain (> 0.) Time constant (> 0.) Maximum controller output (> 0.) Minimum controller output (< 0.) Time constant feedback Transformer saturation control time constant (> 0.) Rate feedback gain (>= 0.) Rate feedback time constant (>= 0.) Potential source gain (>= 0.) Current source gain (>= 0.) Rectifier loading factor (>= 0.) Maximum field voltage (>=0.) UEL input: if = 1, HV gate; if = 2, add to error signal Time constant (>=0.) (note b) Time constant (note b) Notes: a) Ka, Ta, Te must be greater than zero. If Tr or Tb are zero, the respective blocks are bypassed. If Tf is zero, the rate feedback is disabled. b) The lead/lag block (Tc, Tb), which is not in the IEEE ST2A model, is included to match the WECC FM exciter model. The block can be bypassed by omitting these parameters or by setting Tb to zero. Block Diagram: Page 77 Vs V U EL uel i n = 1 uel i n = 2 + Vc 1 1 + sTr − + Σ + 1 + sTc 1 + sTb − Vrmax HV Gate Ka 1 + sTa Efdmax Vr Vb Vrmin Vref + Π 1 sTe Σ − Efd 0 Ke skf 1 + sTf • Ifd Vt Ve = K p Vt + jK i It It Ve • Π Fex(In) In Kc Ifd / Ve Model Compatibility: CIM Model excST2A PSLF Model esst2a exst2* exst2a* PSS/E Model ESST2A EXST2* EXST2A* IEEEX3* IEEET3* DigSilent Model vco_ESST2A Eurostag Model vco_EXST2A * Based on earlier IEEE standards. Can be converted to excST2A. Page 78 excST3A - IEEE ST3A Model Model Name excST3A Description IEEE (1992/2005) ST3A Model Parameters: Parameter Name Bus number Unit ID Tr Vimax Vimin Ka Ta Tb Tc Vrmax Vrmin Km Tm Vmmax Vmmin Kg Kp angp Ki Kc Xl Vbmax Vgmax Units sec. p.u. p.u. p.u. sec. sec. sec. p.u. p.u. p.u. sec. p.u. p.u. p.u. p.u. deg.. p.u. p.u. p.u. p.u. p.u. Typical Value 0.0 0.2 -0.2 200. 0.0 6.67 1.0 10.0 -10.0 7.04 1.0 1.0 0.0 1.0 4.37 20.0 4.83 1.1 0.09 8.63 6.53 Description Terminal bus number in power flow case Generator ID in power flow case Voltage transducer time constant (>= 0.) Maximum error (> 0.) Minimum error (< 0.) AVR gain (> 0.) AVR time constant (>= 0.) AVR lag time constant (>= 0.) AVR lead time constant Maximum AVR output (> 0.) Minimum AVR output (< 0.) Inner loop forward gain (> 0.) Inner loop time constant (> 0.) Maximum inner loop output (> 0.) Minimum inner loop output (<= 0.) Inner loop feedback gain (>= 0.) Potential source gain (> 0.) Phase angle (θp) of potential source Current source gain (>= 0.) Exciter regulation factor (>= 0.) P-bar reactance (>= 0.) Maximum excitation voltage (> 0.) Maximum inner loop feedback voltage (>= 0.) Notes: c) Ka, Km and Tm must be greater than zero. If Tr, Ta or Tb is zero, the corresponding block are bypassed Block Diagram: Page 79 Vgmax Kg Vuel Vref Vimax Vc 1 1 + sTr + − Vi Σ Vmmax Vrmax HV Gate Vr Ka 1 + sTa + 1 + sTc 1 + sTb − Vm Km 1 + sTm Σ • Π Efd + Vimin Vrmin Vbmax Vmmin Vb Vs Vt Kp Vt + j(K i + Kp Xl ) It It Ve • Π Fex (In) In Ifd Kc Ifd / Ve jθ Kp = K p e p Model Compatibility: CIM Model excST3A PSLF Model esst3a exst3* exst3a* PSS/E Model ESST3A DigSilent Model vco_ESST3A EXST3A* * Based on earlier IEEE standard. Can be converted to excST3A. Page 80 Eurostag Model excST4B - IEEE ST4B Model Model Name excST4B Description IEEE (2005) ST4B Model Parameters: Parameter Name Bus number Unit ID Tr Kpr Kir Ta Vrmax Vrmin Kpm Kim Vmmax Vmmin Kg Kp Angp Ki Kc Xl Vbmax Vgmax Units sec. p.u. p.u. sec. p.u. p.u. p.u. p.u. p.u. p.u. p.u. p.u. deg.. p.u. p.u. p.u. p.u. p.u. Typical Value 0.0 10.75 10.75 0.02 1.0 -0.87 1.0 0.0 99. -99. 0.0 9.3 0.0 0.0 0.113 0.124 11.63 999. Description Terminal bus number in power flow case Generator ID in power flow case Voltage transducer time constant (>= 0.) AVR proportional gain (note b) AVR Integral gain (note b) AVR time constant (>= 0.) Maximum AVR output (> 0.) Minimum AVR output (< 0.) Prop. gain of inner loop regulator (note a) Integral gain of inner loop regulator (note a) Maximum inner loop regulator output Minimum inner loop regulator output Inner loop feedback gain (>= 0.) Potential source gain (> 0.) Phase angle (θp) of potential source Current source gain (>= 0.) Exciter regulation factor (>= 0.) P-bar leakage reactance (>= 0.) Maximum excitation voltage (> 0.) Maximum inner loop feedback gain (>= 0.) Notes: a) The inner loop field voltage regulator parameters (Kpm, Kim and Kg) are used for modeling of a compound power source static exciter. Any of these values can be zero, but either Kpm or Kim must be non-zero. To bypass the inner loop field voltage regulator, set Kpm = 1.0, and Kim and Kg to zero. b) Either of the automatic voltage regulator AVR parameters (Kpr, Kir) may be zero but at least one must be non-zero. c) Setting Ta or Tr to zero will bypass the corresponding block. If Ta is zero, a one time step delay is included for this block. Page 81 Block Diagram: Vgmax Kg Vref Vuel Vc 1 1 + sTr Vrmax + + − Voel [voel] Kpr + Σ Kir s + Vr 1 1 + sTa Vmmax − + Σ Vrmin Kpm + Kim s Vm Vmmin LV Gate • Π Efd Vb Vbmax Vs Vt Kp Vt + j(K i + Kp Xl ) It It Ve • Π In Fex (In) Ifd Kc Ifd / Ve jθ Kp = K p e p Model Compatibility: CIM Model excST4B PSLF Model esst4b exst4b* *. Can be converted to excST4B. Page 82 PSS/E Model ESST4B DigSilent Model vco_ESST4B Eurostag Model excST5B - IEEE ST5B Model Model Name excST5B Description IEEE (2005) ST5B Model Parameters: Parameter Name Bus number Unit ID Tr Kr T1 Kc Vrmax Vrmin Tc1 Tb1 Tc2 Tb2 Toc1 Tob1 Toc2 Tob2 Tuc1 Tub1 Tuc2 Tub2 Units sec. p.u. p.u. p.u. p.u. p.u. sec. sec. sec. sec. sec. sec. sec. sec. sec. sec. sec. sec. Typical Value 0.0 200 0.004 0.004 5.0 -4.0 0.8 6.0 0.08 0.01 0.1 2.0 0.08 0.08 2.0 10.0 0.1 0.05 Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant (>= 0.) Regulator gain (> 0.) Firing circuit time constant (>= 0.) Rectifier regulation factor (>= 0.) Maximum regulator output (> 0.) Minimum regulator output (< 0.) Regulator lead time constant Regulator lag time constant (>= 0.) Regulator lead time constant. Regulator lag time constant (>= 0.) OEL lead time constant OEL lag time constant (>= 0.) OEL lead time constant OEL lag time constant (>= 0.) UEL lead time constant. UEL lag time constant (>= 0.) UEL lead time constant UEL lag time constant (>= 0.) Notes: a) For modeling static systems such as ABB UNITROL D, P, F, or 5000 or Brush DCP. Similar to IEEE Type ST1A but with alternative OEL and UEL inputs and transfer functions. b) Kr must not be zero. Any of the time constants may be zero. If any denominator time constant is zero, the respective block is bypassed. c) If T1 is less than 4 times the integration time step, it’s block is replaced by a one time step delay. Block Diagram: Page 83 Vrmax/Kr 1+sToc1 1+sTob1 Vrmin/Kr Vrmax /Kr 1+sToc2 1+sTob2 if (Voel < Verr, jlim = +1 if (Vuel > Verr, jlim = -1 else jlim = 0 Vrmin/Kr Vref Voel Vc 1 1 + sTr S0 + − Σ Vuel Ver r Vrmax/Kr LV Gate HV Gate + Σ • + Vs 1+sTc1 1+sTc2 1+sTb1 Vrmin/Kr 1+sTub1 Vrmin/Kr 0 1+sTb2 Vrmin/Kr Vrmax/Kr 1+sTuc1 Vrmax Vrmax/Kr +1 • jlim Kr −1 Vrmin Vr + − Vt Vrmax 1 Σ Vt Vrmin Kc Vrmax/Kr 1+sTuc2 1+sTub2 Vrmin/Kr Model Compatibility: CIM Model excST5B PSLF Model esst5b **. As of rev. 30, not in PSS/E. Page 84 PSS/E Model ** DigSilent Model Efd 1 + sT1 Eurostag Model Ifd excST6B - IEEE ST6B Model Model Name excST6B Description IEEE (2005) ST6B Model Parameters: Parameter Name Bus number Unit ID Tr Kpa Kia Vamax Vamin Kff Km Kg Tg Vrmax Vrmin Vmult OELin sec. p.u. p.u. p.u. p.u. p.u. p.u. p.u. sec. p.u. p.u. none none 0.012 18. 45. 4.81 -3.85 1.0 1.0 1.0 0.02 4.81 -3.85 1.0 0.0 Ilr Kcl Klr Ts p.u. p.u. p.u. sec. 4.164 1.0577 17.33 0.0 Units Typical Value Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant (>= 0.) Regulator proportional gain (> 0.) Regulator integral gain (> 0.) PI maximum output. (> 0.) PI minimum output (< 0.) Feedforward gain (note b) Main gain (note b) Feedback gain (>= 0.) Feedback time constant (>= 0.) Maximum regulator output (> 0.) Minimum regulator output (< 0.) If non-zero, multiply regulator output by terminal voltage OEL input selector: 1 – before UEL, 2 – after UEL, 0 – no OEL input Field current limiter setpoint (> 0.) Field current limiter conversion factor (> 0.) Field current limiter gain (> 0.) Rectifier firing time constant (not in IEEE model) (>= 0.) Notes: a) For modeling static systems such as Siemens THYRIPOL or ECS2100. b) Kpa and Kia must not be zero. (Kff + Km) must not be zero. Any of the time constants may be zero. If any time constant is zero, the respective block is bypassed. c) If Ts is less than 4 times the integration time step, its block is replaced by a one time step delay. Block Diagram: Page 85 Ilr Kcl + Σ − Ifd Vt Klr VOEL OELin=2 OELin=1 1 1 + sTr − Vrmin Kff − − Vc Vamax Σ + Vref + HV Gate Σ Kpa + + Kia s Va • + Σ Km + − Vrmax Σ LV Gate Vrmin Vamin Vuel + 1 Kg 1 + sTg Vs Model Compatibility: CIM Model excST6B PSLF Model esst6b **. As of rev. 30, not in PSS/E. Page 86 PSS/E Model ** DigSilent Model Eurostag Model Vr 0 1 vmult Vb Π • 1 1 + sTs Efd excST7B - IEEE ST7B Model Model Name excST7B Description IEEE (2005) ST7B Model Parameters: Parameter Name Bus number Unit ID Tr Kpa Kia Tia Tb Tc Tf Tg Kl Kh Vrmax Vrmin Vmax Vmin UELin sec. p.u. p.u. sec. sec. sec. sec. sec. p.u. p.u. p.u. p.u. p.u. p.u. none 0.0 40. 1. 3.0 1.0 1.0 1.0 1.0 1.0 1.0 5.0 -4.5 1.1 0.9 0.0 OELin none 0.0 Ts sec. 0.0 Units Typical Value Description Terminal bus number in power flow case Generator ID in power flow case Filter time constant Regulator proportional gain (> 0.) Feedback gain (>= 0.) Feedback time constant (>= 0.) Lead-lag denominator time constant (>= 0.) Lead-lag numerator time constant (>= 0.) Input lead-lag denominator time constant (>= 0.) Input lead-lag numerator time constant (>= 0.) Low-value gate feedback gain (>= 0.) High-value gate feedback gain (>= 0.) Maximum field voltage output (> 0.) Minimum field voltage output (< 0.) Maximum voltage reference signal (> 0.) Minimum voltage reference signal (> 0.) UEL input selector: 1 – add to Vref, 2 – input HV gate, 3 – output HV gate, 0 – no UEL input OEL input selector: 1 – add to Vref, 2 – input LV gate, 2 – output LV gate, 0 – no OEL input Rectifier firing time constant (>= 0.) (not in IEEE model) Notes: a) For modeling static systems such as Alstom Eurorec, Microrec K4.1 and ALSPA P320. b) Kpa must not be zero. Any of the time constants may be zero. If any time constant is zero, the respective block is bypassed. c) If Ts is zero, its block is replaced by a one time step delay. Block Diagram: Page 87 Voel 1 Vref + 2 Vm a x + LV Gate Σ + 1 HV Gate V m in Σ + Vs + Vuel 2 Voel2 Vuel 3 Vc 1 1 + sTr 1 + sTg 1 + sTf + Σ − HV Gate Kpa Vt * V r m in + LV Gate Σ − Σ − 1 + sTc 1 + sTb + Σ + Vr LV Gate V t * Vr m a x HV Gate • Vt * Vr m in V t * Vr m a x + Kl • Kia 1 + sTia Kh Model Compatibility: CIM Model excST7B PSLF Model esst7b **. As of rev. 30, not in PSS/E. Page 88 PSS/E Model ** DigSilent Model Eurostag Model Ef d 1 1 + sTs Other Excitation System Models To Be Added CIM Model PSLF Model exac1a exdc4 exbbc exeli exeli2 expic1 rexs scrx sexs Page 89 PSS/E Model EXAC1A IEEET4 IEEEX4 IEET5A BBSEX1 EXELI CELIN EXPIC1 REXSYS SCRX SEXS DigSilent Model vco_EXAC1A vco_IEEET4 vco_IEEEX4 vco_IEET5A vco_BBSEX1 vco_EXELI vco_CELIN vco_EXPIC1 vco_REXSYS vco_SCRX vco_SEXS Eurostag Model Power System Stabilizer (PSS) Models The PSS model provides an input (Vs) to the excitation system model to improve damping of system oscillations. A variety of input signals may be used depending on the particular design. Model Interconnections Standard interconnection of PSS models with other models are shown in Figure D-1 and listed in Table D-1. Network frequency speed Pelec Generator Power System Stabilizer (PSS) Vs Excitation System Pmech Eterm Figure D-1 PSS Model Standard Interconnections Table D-1 PSS Model Standard Interconnections Inputs: Name speed frequency Pelec Pmech Eterm Units p.u. p.u. p.u. p.u. p.u. Description Generator speed Terminal voltage frequency (note b) Generator electrical power Generator mechanical power Generator terminal voltage Outputs: Name Vs Units p.u. Description PSS signal to excitation system Initialization Inputs: Name Units speed p.u. frequency p.u. Pelec p.u. Pmech p.u. Eterm p.u. Page 90 Description Generator speed Terminal voltage frequency Generator electrical power Generator mechanical power Generator terminal voltage Source Generator Network Generator Generator Generator Source Generator Network Generator Generator Generator Vs p.u. PSS signal to excitation system (note a) Exc. System Notes: a) Vs is always initialized to zero by the excitation system model. b) If bus voltage frequency is not available from network, the model can calculate it as derivative of the bus voltage angle. Page 91 pssIEEE2B - IEEE PSS2B Power System Stabilizer Model Model Name pssIEEE2B Description IEEE (2005) PSS2B Model Parameters: Parameter Name Bus number Unit ID J1 K1 J2 K2 Vsi1max Vsi1min Tw1 Tw2 Vsi2max Vsi2min Tw3 Tw4 T1 T2 T3 T4 T6 T7 T8 T9 T10 T11 Ks1 Ks2 Ks3 n m Vstmax Vstmin a Ta Tb Notes: Page 92 Units none none none none p.u. p.u. sec. sec. p.u. p.u. sec. sec. sec. sec. sec. sec. sec. sec. sec. sec. sec. sec. p.u. p.u. p.u. none none p.u. p.u. none sec. sec. Typical Value Description Terminal bus number in power flow case Generator ID in power flow case Input signal #1 code Input signal #1 remote bus number Input signal #2 code Input signal #2 remote bus number Stabilizer output max limit Stabilizer output min limit First washout on signal #1 Second washout on signal #1. Stabilizer output max limit Stabilizer output min limit. First washout on signal #2. Second washout on signal #2. Lead/lag time constant Lead/lag time constant Lead/lag time constant Lead/lag time constant Time constant on signal #1 Time constant on signal #2. Lead of ramp tracking filter Lag of ramp tracking filter Lead/lag time constant Lead/lag time constant. Stabilizer gain Gain on signal #2 Gain on signal #2 input before ramp-tracking filter Order of ramp tracking filter Denominator order of ramp tracking filter Stabilizer output max limit Stabilizer output min limit Numerator constant Lead constant Lag time constant a) TW1 and TW3 must be greater than zero. b) Setting TW2 or TW4 to zero will bypass the corresponding washout function. c) T1, T2, T3, T4, T6, T7, T8, and T9 may be zero. d) Set T9 = 0 or n = 0 to get a null effect from the ramp tracking filter. e) The product of n*m cannot be greater than 10. f) The input signal code, J, and the remote bus number, K, specify the input signal used by the stabilizer. If K is zero, the signal is taken from the shaft or terminals of the generator on which the stabilizer is located. If K is non-zero, the signal is taken from bus number K ( for J = 1, 2, 3, 4, or 5 ). g) The values of the input signal code, J, are as follows: 1 2 3 4 5 6 shaft speed frequency of bus voltage generator electrical power generator accelerating power amplitude of bus voltage derivative of bus voltage amplitude . Block Diagram: Vsi1max Input 1 sT w1 1+sTw1 sTw2 1+sTw2 1 1+sT 6 Vsi1min Σ Ks3 1+ sT 8 m (1+ sT 9 ) n Σ Ks1 1+sT1 1+sT2 Ks4 Vstmax Vsi2max Input 2 sT w3 1+sTw3 sTw4 1+sTw4 1+sT3 1+sT4 1 1+sT 7 1+sT10 1+sT11 Vstmin Vsi2min Model Compatibility: CIM Model pssIEEE2B Page 93 Vs a+sTa 1+sTb PSLF Model pss2b pss2a PSS/E Model DigSilent Model PSS2A pss_PSS2A Eurostag Model Other PSS Models To Be Added CIM Model PSLF Model pss1a pss3b pss4b wsccst psssb psssh expic1 ieeest Page 94 PSS/E Model PSS1A PSS3B PSS4B ST2CUT DigSilent Model pss_PSS1A pss_ST2CUT EXPIC1 PTIST1 PTIST3 IEEEST vco_PTIST1 vco_PTIST3 vco_IEEEST Eurostag Model Turbine-Governor Models The turbine-governor model determines the mechanical power (Pm) to the generator model. Model Interconnections Standard interconnection of turbine-governor models with other models are shown in Figure 5-1 and listed in Table 5-1. speed Pref AGC Pmech Turbine-Governor Generator Figure 5-1 Turbine-Goveror Model Standard Interconnections Table 5-1 Turbine-Governor Model Standard Interconnections Inputs: Name speed Pref Units p.u. p.u. Outputs: Name Pmech Units p.u. Description Generator speed Load reference Source Generator See note a Description Generator mechanical power Initialization Inputs: Name Units speed p.u. Pmech p.u. Description Generator speed (= 1.) Generator mechanical power Source Generator Generator Initialization Outputs: Name Units Pref p.u. Description Load reference Source See note a Page 95 Notes: a) Pref is usually held constant for stability analysis, but may be deteremined by a user-written model or, for long-term dynamics, an area-wide automatic generation control (AGC) model. Page 96 govHydro – Hydro Turbine-Governor Model Model Name govHydro Description Simple hydro turbine-governor model Parameters: Parameter Name Bus number Unit ID MWcap Rperm rtemp Tr Tf Tg Velm Gmax Gmin Tw At Dturb qnl Units Typical Value MW p.u. p.u. sec. sec. p.u. p.u./sec. p.u. p.u. sec. p.u. p.u. p.u. Description Terminal bus number in power flow case Generator ID in power flow case Turbine MW capability (> 0.) Permanent droop (R) (> 0.) Temporary droop (r) (> R) Washout time constant (> 0.) Filter time constant (> 0.) Gate servo time constant. (> 0.) Maximum gate velocity. (> 0.) Maximum gate opening (> 0.) Minimum gate opening (>= 0.) Water inertia time constant (> 0.) Turbine gain. (> 0.) Turbine damping factor (>= 0.) No-load flow at nominal head (>= 0.) Notes: a) Per unit parameters are on base of turbine MW capability. "MWcap", the generator MVA base is used. If no value is given for b) The gates travel over a range of 1.0 per unit from fully closed to fully opened. The gate position is normally greater than zero at zero power and normally less than 1.0 when power is 1.0 p.u. Gmax and Gmin are operating limits. c) Tr, Tf, Tg, Tw must be greater than zero. d) Dturb has the dimensions ∆P(pu of mwcap) /∆speed(pu). Block Diagram: Model Compatibility: CIM Model Page 97 PSLF Model PSS/E Model DigSilent Model Eurostag Model govHydro hygov HYGOV Block Diagram: Pref 1. Gmax ω ∆ω Σ 1 1 + sTf Σ (speed) 1 + sTr • rsTr 1 1+ sTg • Gmin gv ∆ω rate limit = Velm R • Π Dturb gv (gate position) d H n/d • Π • Σ q • Σ n hdam Page 98 1 s Tw qnl Π At Σ Pm Other Turbine-Governor Models To Be Added CIM Model PSLF Model ggov1 ggov2 ieeeg1 ieeeg3 hyg3 hygov4 hygovr g2wscc gast gpwscc lfb1 pidgov tgov1 tgov3 crcmgv Page 99 PSS/E Model GGOV1 GGOV2 WSIEG1 IEEEG2 IEEEG3 WSHYGP WSHYDD GAST GASTWD MELGAS WSHYGP LCFB1 PIDGOV TGOV1 TGOV2 TGOV3 CRCMGV IEESGO WPIDHY WEHGOV RAVGOV DUMGOV RAVGOV DigSilent Model GGOV1 WSIEG1 IEEEG3 WSHYGP WSHYDD GAST WSHYGP PIDGOV TGOV1 TGOV2 TGOV3 CRCMGV IEESGO WPIDHY Eurostag Model Aggregate Load Models The load models in this section are used to represent all or part of the real and reactive load from a load in the static (power flow) data. This load is usually the aggregation of many individual load devices. The load models are approximate representation of the aggregate response of the load devices to system disturbances. Models of loads for dynamic analysis may themselves be either static or dynamic. A static load model represents the sensitivity of the real and reactive power consumed by the load to the amplitude and frequency of the bus voltage. A dynamic load model can used to represent the aggregate response of the motor components of the load. Several standard models for agregate load are discussed in this section. Large industrial motors or groups of similar motors may be represented by individual motor models (synchronous or asynchronous) which are usually represented as generators with negative Pgen in the static (power flow) data. These models are discussed in earlier sections Model Interconnections Standard interconnection of load models with other models are shown in the following figure and table: Vbus, fbus Pload Load Model Network Qload Load Model Standard Interconnections Load Model Standard Interconnections Inputs: Name Vbus fbus Units p.u. p.u. Outputs: Name Pload Units p.u. Page 100 Description Terminal bus voltage magnitude Terminal voltage frequency Description Load real power Source Network Network Qload p.u. Initialization Inputs: Name Units Pload p.u. Qload p.u. Vbus p.u. Load reactive power Description Load real power Load reactive power Terminal bus voltage magnitude Source Network Notes: 1. The application program converts the P and Q of the load into a current injection at the bus. Page 101 loadStatic - Static Load Model Model Name loadStatic Description General Static Load Model Parameters: Parameter Name Model Type Scope Type Scope Value Load ID Kp1 Kp2 Kp3 Kp4 Ep1 Ep2 Ep3 Kpf Kq1 Kq2 Kq3 Kq4 Eq1 Eq2 Eq3 Kqf Units Typical Value Description Exponential, ZIP1, ZIP2 Bus, owner, zone, area, system Bus number, area number, zone number Load ID for individual bus load Notes: Equations: Several variations of the static load model are used in various programs. The model type is used to specify these variations. Model type –Exponential Page 102 Ep1 Ep2 Ep3 V V V 1. + K pf ∆f P = P0 K p1 + K p2 + K p3 V0 V0 V0 Eq 1 Eq 2 Eq 3 V V V 1. + K qf ∆f Q = P0 K q1 + K q2 + K q3 V V V 0 0 0 ( ) ( ) Model type – ZIP1 2 1 V V V P = P0 K p1 + K p2 V + K p3 V 1. + K pf ∆f V 0 0 0 2 1 V V V + K q2 + K q3 1. + K qf ∆f Q = P0 K q1 V V V 0 0 0 ( ) ( ) Model type – ZIP2 2 1 V V V P = P0 K p1 + K p2 V + K p3 V + K p 4 1. + K pf ∆f V 0 0 0 2 1 V V V + K q2 + K q3 + K q4 1. + K qf ∆f Q = P0 K q1 V V V 0 0 0 ( ) ( ) Model Compatibility: CIM Model Type General Exponential PSLF Model NONE ZIP1 blwscc ZIP2 zlwscc alwscc wlwscc blwscc zlwscc alwscc wlwscc Page 103 PSS/E Model IEELBL IEELOW IEELZN IEELAR IEELAL IEELBL IEELOW IEELZN IEELAR IEELAL LDFRBL LDFROW LDFRZN LDFRAR LDFRAL DigSilent Model Eurostag Model loadMotor - Aggregate Induction Motor Load Model Name loadMotor Description Aggregate Induction Motor Load Parameters: Parameter Name Bus number Unit ID Pfrac none 0.3 Lfac Ls Lp Lpp Ra Tpo Tppo H D Vt Tv Tbkr none p.u. p.u. p.u. p.u. sec. sec. Sec. p.u. p.u. sec. sec. 0.8 3.2 0.15 0.15 0.0 1.0 0.02 0.4 2.0 0.7 0.1 0.08 Units Typical Value Description Terminal bus number in power flow case Generator ID in power flow case Fraction of constant-power load to be represented by this motor model (between 1.0 and 0.0) Loading factor – ratio of initial P to motor MVA base Synchronous reactance Transient reactance Sub-transient reactance, p.u. Stator resistance, p.u. Transient rotor time constant Sub-transient rotor time constant, sec. Inertia constant, sec. Damping factor, p.u. Voltage threshold for tripping (default = 0), p.u. Voltage trip pickup time (default = 999), sec. Circuit breaker operating time (default = 999), sec. Notes: a) This model is used to represent a fraction of an ordinary load as "induction motor load". It allows load that is treated as ordinary constant power in power flow analysis to be represented by an induction motor in dynamic simulation. Either a “one-cage” or “two-cage” model of the induction machine can be modeled. If Lpp = 0. or Lpp = Lp, or Tppo = 0., only one cage is represented. Magnetic saturation is not modeled. This model is intended for representation of aggregations of many motors dispersed through a load represented at a high voltage bus but where there is no information on the characteristics of individual motors. b) This model treats a fraction of the constant power part of a load as a motor. During initialization, the initial power drawn by the motor is set equal to Pfrac times the constant P part of the static load. The remainder of the load is left as static load. The reactive power demand of the motor is calculated during initialization as a function of voltage at the load bus. This reactive power demand may be less than or greater than the constant Q component of the load. If the motor's reactive demand is greater than the constant Q component of the load, the model inserts a shunt capacitor at the terminal of the motor to bring its reactive demand down to equal the constant Q reactive load. Page 104 . c) If a motor model and a static load model are both present for a load, the motor Pfrac is assumed to be subtracted from the power flow constant P load before the static load model is applied. The remainder of the load, if any, is then represented by the static load model. d) The rotor time constant Tpo and inertia time constant H must be non-zero. e) Ls, Lp, Lpp must all be specified. f) D has the dimensions delta P/ delta speed. The initial value of Pmech or the value coming from an separate mechanical load model, if used, is multiplied by speed raised to the power D to determine the effective mechanical load seen by the motor. g) The parameters Vt and Tv define under-voltage tripping logic. A timer is started if the terminal voltage falls below Vt per unit and continues to run until voltage rises above Vt. If voltage has not risen above Vt when the timer reaches Tv the motor is tripped immediately. h) Per unit parameters are on the motor MVA base. The MVA base is calculated during initialization as the initial motor P in MW divided by the loading factor (Lfac) parameter Block Diagram: Page 105 1. + Te Pmech Σ d n n/d _ Tm + _ Σ ω + ∆ω 1 2Hs Σ speed slip D Σ 1 1 Tpo s E'q Σ Σ 1 Tppo ωo SLIP Tpo Σ 1 s E"q d-AXIS ωo SLIP Lp - Lpp id Σ Ls - Lp ωo SLIP ωo SLIP Tpo Σ 1 1 Tpo s E'd Σ Σ 1 Tppo Σ 1 s E"d q-AXIS Lp - Lpp Σ iq Ls - Lp Model Compatibility: CIM Model loadMotor PSLF Model motorw PSS/E Model CIM5xx, CIMWxx DigSilent Model ElmAsm Eurostag Model Notes: 1. PSS/E has several versions (xx) of the models for application to load at an individual bus (BL), all loads with same owner (OW), all loads in a zone (ZN), all loads in an area (AR), or all loads in the system (AL). The CIMWxx models include a polynomial mechanical load model [Tl = To(Aw^2 + Bw + Co + Dw^E)] which should be represented by a separate mechanical load Page 106 Mechanical Load Models A mechanical load model is used to represent the variation in a motor’s shaft torque or power as a function of shaft speed. Model Interconnections Standard interconnection of mechanical load models with other models are shown in the following figure and table: speed Pmech Mechanical Load Synchronous or Asynchronous Motor Mechanical Load Model Standard Interconnections Mechanical Load Model Standard Interconnections Inputs: Name speed Units p.u. Motor speed Outputs: Name Pmech Units p.u. Description Motor shaft mechanical power Initialization Inputs: Name Units Pmech p.u. speed p.u. Page 107 Description Description Motor shaft mechanical power Motor speed Source Motor Source Motor Motor mechload1 - Mechanical Load Model 1 Model Name mechload1 Description Mechanical Load Model 1 Parameters: Parameter Name Bus Number ID a b d e Units Typical Value Description Motor terminal bus number Generator or Load ID Speed squared coefficient Speed coefficient Speed to the exponent coefficient Exponent Notes: Equations: ( Tmech = T0 aω2 + b ω + c + dωe Pmech = ) Tmech ωDM−1 where : c = 1.0 − a − b − d ωoDM−1 To = initial torque = Tmech(ωo ) ωo = initial motor speed Model Compatibility: CIM Model Type mechload1 Page 108 PSLF Model apfl spfl PSS/E Model DigSilent Model mdm1 mdm3 mdm5 Eurostag Model
