Pulse by pulse current limiting technique for SPWM inverters

摘要

Impactive current overshoot is usually observed in SPWM inverterwhen impulsive loads are loaded. So far, several methods have beenproposed to solve this problem, such as mean current feedback control ortemporarily pulling down the voltage reference. Nevertheless, they bothhave shortcomings. This paper introduces a pulse by pulse currentlimiting (i.e. instantaneous drive pulse locking) technique which cansubstantially lessen the impact on SPWM inverter during all kinds ofimpulsive loading (even the short-circuit of the load). This techniquehas been used successfully in a 3.5 kW, 400 Hz single-phase full-bridgeSPWM inverter. By the pulse by pulse current limiting technique, thesuccessful loading of impulsive loads is ensured, and the loadingprocess has little influence on the normal supply to other importantloads which are powered by the inverter at the same time