Invariant modulation strategy for Two-stage Direct Power Converter

The modulation strategy with the current invariance to input voltage disturbances and novel modulation algorithms for two-stage direct power converter are presented. Based on theoretical approach, the conditions for getting the current invariance are obtained. The novel modulation algorithms with minimum input current distortions are developed according to the proposed strategy. The switching sequence of the converter with power losses optimization procedure is specified. The performance efficiency of the proposed strategy and modulation algorithms in comparison with a conventional one are shown by simulation of the conversion procedure under balanced and unbalanced mains.