Circuitry for electronic branch pairs in a reverse-parallel circuit

摘要

For self-commutated multi-quadrant converters, which are used, inter alia, in speed-controlled three-phase drives, circuitry is specified, which reduces the switching-on and switching-off losses of the semiconductor switches and diodes. It is particularly suitable for GTO thyristors (thyristors which can be turned off) and MOS field-effect transistors. Because the switching losses and the voltage surges on the semiconductor switches are kept very small, high efficiencies and good power-utilisation of the semiconductor switches result. Apart from the reactive elements - switching-on relief inductor and switching-off relief capacitor - which are required in principle, only one further capacitor is required for intermediate storage of the circuitry energy. The switching-on relief inductor may be formed partially or completely by the stray inductance of the supplying or supplied DC voltage source.