Load commutated inverter gating control system and motor drive with such control system

摘要

A synchronous motor drive includes an inverter gating control system using three counters wherein two counters respond to 180 DEG apart zero crossings for providing units of time in terms of clock units, and the third counter is at a computed time interval preset with a count to be counted down to derive the remaining time which is to elapse until a predetermined firing angle is reached, at which time firing of the thyristor of the inverter is triggered.