An Improved Single-Phase Direct PWM Inverting Buck-Boost AC-AC Converter

A single-phase inverting buck-boost ac-ac converter is proposed in this paper. The proposed converter has no shoot-through and dead-time problems and, like conventional dc-dc converters, it can be operated with simple pulse width modulation (PWM) control. It offers high frequency and high efficiency operation because high speed mosfet can be used as switching device without the reverse recovery issues and losses of its body diode. The proposed converter features quasi-continuous input and output currents, high input power factor, low total harmonic distortion of input and output currents, and high efficiency. A 460 W laboratory prototype was constructed and tested with interleaved and complementary PWM controls using a resistive and inductive load. Detailed experimental results are provided to show the novelty of the proposed converter. Experimental results confirmed that the proposed converter can obtain 93.8% efficiency at 60 kHz switching frequency.