Summary of some important points in analysis 4 When analyzing a thyristor circuit, start from a diode circuit with the same topology. The behavior of the diode circuit is exactly the same as the thyristor circuit when firing angle is o 4 a power electronic circuit can be considered as different linear circuits when the power semiconductor devices are in different states. The time-domain behavior of the power electronic circuit is actually the combination of consecutive transients of the different linear circuits 4 Take different principle when dealing with different load For resistive load: current waveform of a resistor is the same as the voltage waveform For inductive load with a large inductor: the inductor current can be considered constant 16
Power Electron cs i 16 Summary of some important Summary of some important points in analysis points in analysis When analyzing a When analyzing a thy ris t o r circuit, start from a diode circuit with circuit, start from a diode circuit with the same topology. The behav the same topology. The behavior of the diode circuit is exactly the diode circuit is exactly the same as the the same as the thyristor thyristor circuit when firing angle is circuit when firing angle is 0. A power electronic circuit can A power electronic circuit can be considered as different linea be considered as different linear circuits when the power semico circuits when the power semiconductor devices are in different nductor devices are in different states. The time states. The time -domain behav domain behavior of the power electronic ior of the power electronic circuit is actually the combinat circuit is actually the combination of consecutive transients of ion of consecutive transients of the different linear circuits. the different linear circuits. Take different principle when dealing with different load Take different principle when dealing with different load – For resistive load: current waveform of a resistor is the same For resistive load: current waveform of a resistor is the same as the voltage waveform – For inductive load with a large inductor: the inductor current For inductive load with a large inductor: the inductor current can be considered constant be considered constant
PeRec 2.2 Three-phase controlled (controllable)rectifier 2.2.1 Three-phase half-wave controlled rectifier (the basic circuit among three-phase rectifiers 2.2.2 Three-phase bridge fully-controlled rectifier (the most widely used circuit among three-phase rectifiers)
Power Electron cs i 17 2.2 Three -phase controlled phase controlled (controllable) rectifier (controllable) rectifier 2.2.1 Three -phase half phase half-wave controlled rectifier wave controlled rectifier (the basic circuit among three (the basic circuit among three -phase rectifiers) phase rectifiers) 2.2.2 Three 2.2.2 Three -phase bridge fully phase bridge fully -controlled rectifier controlled rectifier (the most widely used circuit among three (the most widely used circuit among three -phase rectifiers) rectifiers)
F 2.2.1 Three-phase half-wave controlled rectifier Resistive load,a=0° Olar 4 OYY mhVT2 R +p Common -cathode connection 中 Natural commutation point 18
Power Electron cs i 18 2.2.1 Three -phase half phase half-wave controlled rectifier controlled rectifier Resistive load, Resistive load, α = 0 º u2 ua ub uc O ωt 1 ωt 2 ωt 3 uG O ud O O uab u ac O iVT1 uVT1 ωt ωt ωt ωt ωt T R u d i d VT 2 VT1 VT3 Common -cathode connection cathode connection Natural commutation point Natural commutation point
PEREC Resistive load,a=30° ua " VT d R ot
Power Electron cs i 19 Resistive load, Resistive load, α = 30 º u2 ua ub uc O ωt O ωt O ωt O ωt O ωt u G ud uab u ac ωt 1 iVT1 uVT1 uac T R u d i d VT 2 VT1 VT3
PEREC Resistive load,a=60° XXXXY ⅥT24 R
Power Electron cs i 20 Resistive load, Resistive load, α = 60 º T R u d i d VT 2 VT1 VT3 ωt ωt ωt ωt u2 ua ub uc O O O O uG ud iVT1