Modulation Method for a Multiple Drive System Based on a Two-Stage Direct Power Conversion Topology With Reduced Input Current Ripple

A new two-stage multi-drive direct power conversion (DPC) topology suited for multi-drive application is proposed, having an input port for a three-phase power supply and several output ports to connect three-phase loads, which are independently controlled and allow for sine wave in-sine wave out operation. This is a cost effective topology compared to a standard matrix converter because the multiple three-phase loads share the cost of the controlled rectification stage. A new method to reduce the high frequency ripple from the input current is also proposed based on interleaving the switching patterns of the inversion stages, which have to form two groups, allowing for size reduction of the input current filter. This is validated by experiments on a realistic laboratory prototype, while its limitations are determined by simulations.