Distributed Control for AC Motor Drive Inverters in Parallel Operation

A distributed control for pulsewidth modulation inverters in parallel operation to feed an asynchronous motor is proposed. The phase angle of the sinusoidal reference for each inverter is represented as a square signal and shared among the inverters and is pre-synchronized cycle-by-cycle with each other. And then the current sharing is regulated by introducing the circulating current into the mild adjustment of the sinusoidal references. All the sense and control for parallel operation are embedded in inverters distributed and a redundant power system is achieved. A prototype is built with experimental results given to verify the control proposed.