Power Electronics and Motor Drive Systems

5.5. Twelve-Pulse Fully Controlled Thyristor Rectifier

Fig. 5.26 shows the power circuit of the 12-pulse full-controlled rectifier. This topology exhibits the same advantages as that of the 12-pulse diode rectifier and additionally provides output voltage control. Fig. 5.27 shows the voltage and current waveforms for resistive–inductive load. As shown in Fig. 5.27, the gating pulses of the top six-pulse rectifier have a phase difference of 30° in comparison to the corresponding bottom one. When the load is resistive–inductive with ωL ≫ R, the current waveforms of this rectifier are the same as that of 12-pulse diode rectifier which are shown in Figs. 4.15, 4.16, and 4.18. Therefore, when the output current is pure dc of I¯o value, the current ...