2 MANAGEMENT STRATEGIES TO DEAL WITH PWM INVERTERS CONTROL VARIABLE SATURATION

Conventional PM (permanent magnets) synchronous drives are supplied by PWM (pulse-width modulation) inverters. Limitation of the inverter's control variables has two important consequences: a reduction of the average torque, and important current and voltage ripples. In this paper, two strategies are proposed to deal with this problem for a two-current loop structure. The first one allows the use of the maximum available voltage without current distortions in case of successive limitations. The second one is an attempt to maintain a set of balanced voltages at the machine terminals to reduce the torque ripples in case of double limitations.