A Cost-Reliability Trade-Off Fault-Tolerant Series-Resonant Converter Combining Redundancy and Reconstruction

Adding redundant converters or switches are two common strategies to achieve fault-tolerant operation of converters. The former one is straightforward but costly, while the latter one is cost-effective but with sacrifice on the reliability as it only works for switches’ failure. Aiming to achieve a good trade-off between cost and reliability, a novel fault-tolerant full-bridge series-resonant converter (FB-SRC) which only needs a redundant half-bridge SRC (HB-SRC) to gain fault tolerance for all fault-prone components is proposed in this article. The proposed converter can keep working normally when short-circuit fault or open-circuit fault happens on switches, diodes, or the output filter capacitor. After fault occurs, the redundant HB-SRC converter will combine the remaining healthy part of original FB-SRC to reconstruct an input-parallel and output-series dual HB-SRC, which can maintain the rated output power with reduced cost. In the article, component's reliability of SRC is first analyzed. Then, operation and performance analysis of the proposed fault-tolerant converter is introduced in detail. As the voltage/current stresses of components are almost the same during the prefault and postfault operation, the converter design is simple. Finally, experimental results of a 500 W prototype are also given to verify the effectiveness.