Input Power Line Total Harmonic Distortion (THD) with SS2k 1 Initials Current 500 250 Amps Power Line Input Current , SS2k 6 pulses without DC link inductor 0 -250 -500 Amps Current 200 150 100 50 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Harmonic # 2 Initials Voltage 400 200 Volts Power Input Voltage ,SS2k 6 Pulses VSD without DC Link Inductor 0 -200 -400 Voltage Volts 300 200 100 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Harmonic # 3 Initials DC Link Inductor 4 Initials Power Input Current, 6 Pulse SS2k with DC link Inductor +500 0 -500 0° 5 Initials 90° 180° 240° 360° 6 Pulse SS2k with DC link inductor Input Current 6 Initials Current Harmonics Percentage as function of ZPU with 6 Pulses SS2kVSDs 1 Diminishing returns after .06 for adding Z. Per Unit Current Harmonics 0.8 THD IFL 0.6 5th 0.4 ZPU = ----ISC 7th 0.2 0 0 0.02 0.04 0.06 Pow er System Per Unit Z 7 Initials 0.08 0.1 0.12 12 Pulse SS2k VSD Block Diagram A Phase Inverter Rectifier Input Transformer 480V 3 Phase Filter B Phase Inverter 480V 3 Phase Phase Shift by 30 deg. Rectifier Inverter VSD 8 Initials C Phase 12 Pulses SS2k Electrical Diagram 9 Initials 12 Pulse SS2k VSD Input Power Current +500 0 -500 0° 10 Initials 90° 180° 240° 360° 12 Pulse SS2k VSD Input Power Current 11 Initials Comparative Test of 200 KVA SS2k with link reactor Vs. 12 Pulse SS2k, both loaded with motor in test well 12 Initials current harmonic Speedstar 6 pulse Speedstar 12 pulse 1 5 7 11 13 17 19 23 25 100.0% 26.0% 9.5% 6.7% 4.3% 2.9% 2.3% 1.25% 1.24% 100.0% 3.2% 2.0% 6.2% 3.4% 0.8% 0.6% 0.9% 0.7% CURRENT HARMONICS ELIMINATED BY 12 PULSE SS2k (72.0%) eliminated harmonics from 6 Pulse system (28.0%) remaining harmonics from 6 Pulse system 13 Initials Current 500 250 Amps 6 Pulses SS2k Input Power Current with Mirus Lineator 0 -250 -500 Amps Current 200 150 100 50 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Harmonic # 14 Initials Voltage 400 200 Volts SS2k 6 pulses Input Power Voltage with Mirus Lineator 0 -200 -400 Voltage Volts 300 200 100 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Harmonic # 15 Initials Field Installation Electrical Diagram of 6 pulses SS2k Six pulse VSDs 16 Initials Quasi 12 Pulse Field Installation Electrical Diagram 17 Initials 12 Pulse SS2k Installation Electrical Diagram (note separate input transformers) 18 Initials Single line - 12 Pulse VSD IEEE 519 Requirement 19 Initials Single line - 6 Pulse IEEE 519 Requirement 20 Initials Commutation on a SCR Bridge CURRENT SCR “A” ON SCR “B” ON OVERLAP REGION 0 SCR “B” OFF SCR “A” OFF SWITCHING POINT 21 Initials Three Phases 6 Pulses SCR Bridge Waveform 22 Initials Example of Line Voltage distortion caused by SCR commutation 23 Initials 24 Initials 25 Initials