Control method for parallel-connected power converters

摘要

A control method for the parallel-connected power converters includes a control circuit comprising a voltage feedback circuit and a current feed-forward circuit. The voltage feedback circuit, consisting of a voltage regulated control circuit and a waveform control circuit, is used to control the power converter's output voltage with constant amplitude and low total harmonic distortion. By adjusting the gain of waveform control circuit, it can regulate the current distribution among the parallel-connected power converters. The current feed-forward circuit separates the power converter's output current into the fundamental component and the harmonic component, and amplifies them by different gain. The amplified fundamental component acts as a fundamental resistor to suppress the circulating current among the parallel-connected power converters, and the amplified harmonic component acts as a harmonic damper for preventing from high frequency oscillation generated by the L-C filter.