Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 1 Power Converter Systems Graduate Course EE8407 Ryerson Campus Bin Wu PhD, PEng Professor ELCE Department Ryerson University Contact Info Office:ENG328 Tel: (416) ext:
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 2 Multi-pulse SCR Rectifiers
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 3 Lecture Topics Six-pulse SCR Rectifier (Building Block) 12-, 18- and 24-pulse SCR Rectifiers THD and PF Multi-pulse SCR Rectifiers
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 4 Why Use Multi-pulse SCR Rectifiers? To reduce line THD To improve input power factor To avoid semiconductor devices in series. Multi-pulse SCR Rectifiers
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 5 Converter Configuration Assumption: 1) Ideal SCRs - no power loss 2) dc current ripple free Use constant current source I d as a load Six-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 6 Waveforms Average dc voltage Six-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 7 Fourier Analysis RMS current THD Six-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 8 Power Factor (PF) Displacement Power Factor Overall Power Factor Six-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 9 Waveforms at Various Firing Angles Six-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 10 Effect of Line Inductance L s Six-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 11 Waveform During SCR Commutation Six-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 12 DC Voltage Reduction (caused by commutation) S 1 and S 5 on (during commutation) from which Since i a + i c = I d, and i d is constant from which Six-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 13 DC Voltage Reduction Since Shaded Area A γ Average dc voltage loss Average dc output voltage Six-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 14 Commutation Interval A γ can be rearranged as where Substitute from which Six-pulse SCR Rectifier into the above equation
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 15 Line Current Waveforms L s = 0.05pu Six-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 16 Line Current THD Six-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 17 Power Factor Six-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 18 Topology Main Benefits - Low line current THD - No SCRs in series 12-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 19 Application Example Used for current source inverter (CSI) fed drive 12-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 20 Waveforms of Idealized Rectifier (L s = L lk = 0) 12-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 21 Fourier Analysis Secondary currents 12-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 22 Fourier Analysis (continued) Secondary currents referred to the primary side Primary line current 12-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 23 Line Current THD Secondary side Primary side 12-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 24 Line Current Waveform (L s 0 ) 12-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 25 THD and PF 12-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 26 Rectifier Configuration 18-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 27 Waveforms 18-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 28 Line Current THD 18-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 29 Rectifier Configuration 24-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 30 Line Current THD 24-pulse SCR Rectifier
Textbook: Bin Wu, ‘High-Power Converters and AC Drives’, Wiley - IEEE Press, 2006 EE8407 Topic 4 31