Development of Switched-Capacitor bi-directional DC-AC converter for inductive and capacitive loads

This paper presents a research for switched-capacitor (SC) bi-directional DC-AC converter for inductive and capacitive loads. The proposed converter keeps high efficiency even if the phase of the load is changed widely, since the output energy returns to the input. The validity of the proposed converter is confirmed by SPICE simulations. The SPICE simulations showed that (1) the output voltage is kept a sinusoidal for the capacitive load and/or the inductive load, (2) the power conversion efficiency eta is 93% or more regardless the phase thetas of the load (-72< thetas < 72) without output regulation, and (3) the efficiency eta_reg is 80% or more (-54< thetas < 54) with regulation.