A novel single-phase six-switch AC/AC converter for UPS applications

A new reduced-switch-count converter topology is introduced and proposed for UPS applications in this paper. The modulation scheme of this novel converter is developed and a method is devised for calculating the optimal operating point of the converter based on the design specifications in order to maximize dc bus voltage utilization while minimizing the output voltage THD and switching loss. Moreover, a strategy is suggested for battery charging period which increases converter input power and hence accelerates battery charging process. The proposed converter possesses desirable characteristics of an ideal AC/AC converter such as low THD of input current and output voltage and unity power factor. The validity of theoretical issues is confirmed by simulation results.