High power converter or inverter using semiconductor elements in parallel - operates each bridge path of three thyristors by single pulse generator and counter circuit

摘要

A power switching solid state device for use in a parallel mode provides the basis of an a.c. inverter. An a.c. bridge circuit has three parallel thyristors in each bridge to form a 50 Hz system. The three parallel thyristors are operated by a firing pulse transmitter that has on the secondary side a triggered electronic counter that provides the phased signals for operating the three devices. This allows the number of pulse generators to be reduced to 6 from 18 for the full bridge. ADVANTAGE - Drives power semiconductor components sequentially in short time periods related to heat-time constants instead of simultaneously so that current distribution between the semiconductor components is independent of their individual technical data and circuit construction, avoiding the usual parallel switching factor reducing permissible loading.