Reconfigurable Rectifier-Based Resonant Converter for Wide Output Voltage Applications

Newer electric vehicle (EV) architectures require different charging voltages compared to the old systems, and to improve compatibility between chargers, a wide output voltage is desirable. While resonant converters offer high efficiency, the efficiency is typically closely tied to fixed operating conditions, making it difficult to maintain high efficiency across a wide output voltage range. This paper proposes a secondary rectifier architecture that enables wide-range output voltages with minimal complexity. With two switches, the rectifier can generate four discrete output voltages to achieve a wide voltage range without changing the switching frequency. Voltage expressions are derived from the analysis of equivalent circuit models for the four operation modes. To validate the operation of the proposed topology, simulation results are described and discussed for a 1 kW output power converter, with an input voltage of 150 V, and rectifier conversion gains of 1, 1.33, 2, and 4.