Design and Implementation of Novel Noninverting Buck–Boost AC–AC Converter for DVR Applications

This article proposes the new noninverting buck–boost ac–ac converter, which can minimize the reverse recovery loss by disabling the body diodes of switches and using the external fast recovery diodes for its current freewheeling. In particular, the proposed ac–ac converter takes advantages of metal-oxide semiconductor field effect transistors and external fast recovery diodes to achieve the high efficiency. Also, it has the high reliability without the shoot-through and dead-time considerations in the circuit. Moreover, it can be simply implemented without employing the conventional commutation control. This results in decreasing the control complexity. As its proper application, a new type of dynamic voltage restorer (DVR) based on the proposed noninverting buck–boost converter is described. It enables to solve the voltage sag and swell problems by utilizing both positive and negative gains of converter. Then, the hardware prototype of proposed ac–ac converter and DVR are implemented to verify their practical effectiveness.