Formulation and Distortion Compensation of Half-Bridge AC-AC Converters Under Asymmetrical Control

This paper considers a half-bridge AC-AC converter that uses bidirectional switches and adopts asymmetrical control as the output voltage control scheme. To yield a pure sinusoidal output voltage waveform, it is generally needed to compensate possible distortion due to nonlinear loading. For a new approach to the compensation, we focus on the convex voltage-gain-to-duty-ratio characteristic of the converter. We propose a simple scheme for distortion compensation employing only analog circuit components. The proposed system is experimentally evaluated and low-distortion output voltage is achieved for a nonlinear load.