PEREC Electro-motive force(EMF)load With resistor E R ot E g Discontinuous current id
Power Electron cs i 11 Electro Electro -motive -force (EMF) load force (EMF) load With resistor With resistor a) b) R E i d u d i d O E u d ωt Id O ωt α θ δ Discontinuous current i Discontinuous current i d
PEREC Electro-motive force(EMF)load With resistor and inductor 4 When L is large enough, the output voltage and current waveforms are the same as ordinary inductive load t When L is at a critical value ab=π E L=2v22=287×10-3V2(2 dmin 12
Power Electron cs i 12 Electro Electro -motive -force (EMF) load force (EMF) load With resistor and inductor With resistor and inductor When L is large enough, the output voltage and When L is large enough, the output voltage and current waveforms are the same as ordinary current waveforms are the same as ordinary inductive load. inductive load. When L is at a critical value When L is at a critical value O u d 0 E i d ωt ωt π δ α θ = π dmin 3 2 dmin 2 2.87 10 2 2 I U I U L − = = × πω (2-17)
F 2.1.3 Single-phase full-wave controlled rectifier Cu u,IVt, uAllIR b) 4 Transformer with center tap e Comparison with single-phase bridge fully-controlled rectifier
Power Electron cs i 13 2.1.3 Single -phase full phase full -wave controlled rectifier controlled rectifier a) b) u1 T R u 2 u 2 i 1 VT1 VT 2 u d u d i 1 O O α ωt ωt Transformer with center tap Transformer with center tap Comparison with single Comparison with single -phase bridge fully phase bridge fully -controlled rectifier controlled rectifier
F 2.1.4 Single-phase bridge half-controlled rectifier 个个 9本9 T-a 事Haf- control 4 Comparison with fully-controlled rectifier 4 Additional freewheeling diode
Power Electron cs i 14 2.1.4 Single -phase bridge phase bridge half -controlled rectifier controlled rectifier Half-control control Comparison with fully Comparison with fully -controlled rectifier controlled rectifier Additional fre Additional fre ewheeling diode wheeling diode O b) u2 O ud i d I d O O O O O i 2 Id Id I d Id I d α ωt ωt ωt ωt ωt ωt ωt α π− α π− α iVT i 1 VD4 iVT i 2 VD3 iVD R a b R L u 2 i 2 u d i VT d 1 VT2 VD3 VD4 VDR T
Another single-phase bridge half-controlled rectifier load 本本9 4 Comparison with previous circuit No need for additional freewheeling diode Isolation is necessary between the drive circuits of the two thyristors 15
Power Electron cs i 15 Another single Another single -phase bridge phase bridge half -controlled rectifier controlled rectifier T u 2 VD3 VD4 VT1 VT2 load Comparison with previous Comparison with previous circuit: circuit: – No need for additional freewheeling diode No need for additional freewheeling diode – Isolation is necessary between the drive circuits of the two Isolation is necessary between the drive circuits of the two thyristors thyristors