Drive circuitry for mains supplied AC converter - operates turn off capacitor via GTO thyristor with coupled inductance and diode

摘要

The converter (WR) consists of a bridge circuit of thyristors (V1-V6) coupled to the mains voltage and with phase connections to coupling diodes (V11,V31,V51). The diodes connect to a common turn off capacitor (LKo) and a GTO thyristor (V21). These connect to a saturation inductance coil (LDr) and a coupling diode (V22) to the d.c. intermediate circuit (EEL) with an inductance (LDr). Outputs extend to the three phase loads (U1, U2, U3) via a commutation inductance (Lk) and resistors. ADVANTAGE - Reduced size and voltage of turn off capacitor.