Optimizing the performance of a 3-phase diode rectifier using 3-level harmonic correction circuits with low switching frequencies

The performance of a three-phase diode rectifier is analyzed when using three-level harmonic correction networks with a low switching frequency. The networks considered have low per-unit current ratings and use an inductor to lower the size of the rectifier AC supply inductors required to obtain harmonic current distortion levels less than 5%. Performance curves are presented, including device current ratings, to enable the inductor size and device switching patterns to be chosen to minimize the rectifier input current harmonic distortion and to maintain a unity fundamental power factor. The operation and performance of the circuits are illustrated