A NEW SINGLE-PHASE TO 3-PHASE CONVERTER WITH ACTIVE INPUT CURRENT SHAPING FOR LOW-COST AC MOTOR-DRIVES

In this paper, a new single-phase to three-phase converter for low-cost ac motor drive is proposed. The proposed converter employs only six switches and incorporates an active input current shaping feature that results in sinusoidal input current at close to unity power factor. The front-end rectifier in the proposed converter permits bidirectional power flow and therefore provides for excellent regulation against fluctuations in source voltage. This feature also facilitates regenerative braking of the ac motor drive. An easy to implement control strategy to maintain near unity power factor over the full operating range is detailed. Suitable design guides for the selection of filter components is presented. Finally, simulation and experimental results are given to verify the developed theoretical models.