Unity input displacement factor correction principle for direct AC to AC matrix converters based on modulation strategy

摘要

Modulation strategies for a matrix structured direct AC to AC converter are developed. In principle, for a given set of input three-phase voltages, any desired set of output voltages can be synthesized by suitable toggling matrix switches. Mathematical proof that the direct AC to AC matrix converter can operate with unity displacement factor is provided by analyses based on the switching matrix approach. A symmetric and antisymmetric switching strategy is developed for synthesizing an output voltage vector from the appropriate combination of input voltage vectors. Unity displacement factor operation is achieved by using the combined symmetric and antisymmetric modulation strategy. This combined algorithm enables unity displacement factor operation without current sensing and current control.