A Fault-Tolerant Series-Resonant DC-DC Converter

The series-resonant DC-DC converter (SRC) is widely used as power supply for telecommunications, wireless power transfer for electrical vehicle, and high-voltage power supplies. Recently, it became very popular in solid-state transformer application, where fault tolerance is a highly desired feature and it is obtained through redundancy. This letter proposes a reconfiguration scheme for the SRC for the case of failure in one semiconductor, which could drastically reduce the need of redundancy. Using the proposed scheme, the full-bridge based SRC can be reconfigured in a half-bridge topology, in order to keep the converter operational even with the failure [open circuit (OC) or short circuit (SC)] of one switch. As a drawback of this technique, the output voltage drops to half of its original value. Therefore, a novel reconfigurable rectifier based on the voltage-doubler topology is proposed as a solution to keep the output voltage constant after the fault. To verify the feasibility of the proposed scheme, the converter is tested experimentally in a 700-600 V prototype with 10 kW of output power. An insulated gate bipolar transistor (IGBT) SC fault is tested and the results confirm the effectiveness of the proposed approach.