Novel current mode AC/AC converters with high frequency AC link

The research on AC/AC converters are mainly limited to the thyristor phase-controlled cycloconverters and matrix converters without electrical isolation. In this paper the voltage mode AC/AC converter with high frequency electrical isolation based on forward converter was proposed. A family of the current mode AC/AC converters with high frequency electrical isolation based on flyback converters, which can transfer one unregulated sinusoidal voltage with high THD into another regulated constant frequency sinusoidal voltage with low THD, are proposed and deeply investigated in this paper. The operational mode, steady principles and transient voltage feedback control strategy of the converter are investigated. The output characteristic curve, its relation to internal resistance, the design criterions for the key circuit parameters, the simulation and test results are given. The converters lay key technical foundation on new-type regulated sinusoidal ac power supplies and electronic transformers.