Phase-shifted controlled forward mode AC/AC converters with high frequency AC links

A circuit topology family of the forward mode AC/AC converters with high frequency ac link are proposed. The kind of circuit topologies are constituted of input cycloconverter, high frequency transformer, and output cycloconverter. The phase-shifted control strategy and steady principles are deeply investigated. The output characteristics of the converters are given. By using commutation overlap of the output cycloconverter and the polarity selection of the input voltage and the output filtering inductance current, the leakage inductance energy and the output filtering inductance current are naturally commutated, and the surge voltage and the surge current of the cycloconverters are overcome. The converters have the advantages such as simple topology, two-stage power conversions(LFAC/HFAC/LFAC), bi-directional power flow, high frequency electrical isolation, good line current waveform and output voltage waveform, and strong load adapting function. The converters lay key technical foundation on new-type regulated sinusoidal ac power supplies and electronic transformers. The correction and advancement of the converters are well verified by simulation and principle test.