A novel transformerless AC-AC static power converter for residential applications

A new type of transformer less ac-ac converter based on the switched-capacitor (SC) has been proposed in this paper, intended to replace transformers. The merits of the proposed ac-ac converter can be understood with the fact that the use of magnetic elements are eliminated i.e. without inductors and transformers, ability to be bidirectional, high efficiency, and voltage stress of the active switches can be reduced to half the supply voltage by carefully choosing the capacitor values. Reduction in switching losses i.e. by reducing the capacitor, Light weight, small size and high power density are the result of using only switches and capacitors in the power stage of these converters. These SC converters are applicable in commercial and residential needs for example: PMSM and Induction motor fed drive applications. The nominal efficiency obtained 97.25% respectively.