Topic 17Main contentsThree-phase Thyristors Rectifier
Main contents • Three-phase Thyristors Rectifier Topic 17
6-4 Three-Phase Full-BridgeConvertersNa大。大(b)(a)·Common-cathode group and common-anode group ofthyristors·Numbering of the 6 thyristors indicates the trigger12345612sequence:
6-4 Three-Phase Full- Bridge Converters •Common-cathode group and common-anode group of thyristors •Numbering of the 6 thyristors indicates the trigger sequence: 1→2→3→4→5→6→1→2→
6-4-1 ldealized Circuit with Ls=0 and ia(t)=ld3TT达T5DaT天T6ATNN22(a)(b)Figure 6-19 Three-phase thyristor converter with L, = O and a constant dc current
6-4-1 Idealized Circuit with Ls=0 and id (t)=Id
1 anlysisthe instant of natural conduction.the crossover pointof phase (or line) voltage (wty,wt2,wt3,wt4,wts,wt)UdUPnVeaUbnTVanUen3iaVdoot(a)0Vdwt=0ia66Thewaveformsofα=O°ia = iT1-iT43/2V.sinotdot=1.35VLL(6 -36)doTE-mail:xihuang@bitu.edBu.cn
1 anlysis • the instant of natural conduction.——the crossover point of phase (or line) voltage (ωt1 ,ωt2 ,ωt3 ,ωt4 ,ωt5 ,ωt6 ) π 1 3 2π E-mail: xjhuang@bjtu.ed3u.c3n d0 ia = iT 1 −iT 4 V = (6 −36) π 2VLL LL sintdt =1.35V The waveforms of = 0º vd
UenUbnVanUpn-t(b)0wt=0αVenUNnia+ot0(c)iaia-.-UcbUcaUbaUbeUacVabUebUdOcnUbnDanVenuda@(d)0ot=oaWaveforms in the converter of Fig. 6-19.Figure6-202瓜+α13/2Vusin otdot= 1.35Vucosα = Vao cosα(6- 40)1元da元+α373
31π 3 3π V = (6 − 40) 2π + + d 2VLLsin t d t = 1.35 VLL cos = Vd0 cos