Single-Stage Buck–Boost Bipolar Three Terminals Output AC/DC Power Converter

This article introduces a novel bipolar ac/dc converter designed for dc applications. The proposed converter transforms an input ac voltage into two independent dc output voltages while maintaining a unity power factor. The output dc voltages can be higher or lower than the input ac voltage, allowing the converter to operate across a wide range of input or output voltages. The converter utilizes four active switches; however, only one operates at high frequency at a time, while two others operate at line frequency. The proposed converter features simple operation and shares a common ground between the input ac and output dc, enhancing the reliability of the power conversion system. A detailed analysis of the converter is provided, along with the development of control strategies. Simulation results, followed by experimental findings from a 550-W hardware prototype, are presented to verify the functionality and effectiveness of the proposed converter for dc applications.