Comprehensive analysis of a three‐phase DC–DC resonant converter with an open delta‐wye transformer using variable frequency

Abstract A three‐phase soft‐switched DC–DC resonant converter with variable frequency to perform the output voltage control is proposed. The open delta‐wye connection provides a double output voltage reducing the primary current stress, turns ratio, weight and volume of high‐frequency transformer. To achieve high efficiency, an LLC resonant tank is designed so that all switches can perform zero‐voltage switching for the entire power range. In order to verify the operating principle of the converter, a design example is described, with the following converter specifications: input voltage 96 V, output voltage 380 V and a switching frequency up to 120 kHz. The feasibility and practicality of the proposed converter are confirmed by experimental results with a 1.5 kW prototype.