Fault Reconfiguration of Series-Connected Dual-Transformer Active Bridge Converter for Reliable Shipboard DC System

This article proposes a dynamic fault reconfiguration method based on a multi-port converter named dual-transformer series-connected active bridge converter (DT-SCAB converter) which interconnects DC bus and integrated energy storage devices and is applied in ship board system. The proposed converter enables to clear short-circuit fault at the output port connected with DC bus and effectively improves reliability of shipboard power system under complicated conditions. In condition of short-circuit fault occurrence at one of the output terminals, the proposed fault reconfiguration method isolates the faulty terminal and maintains constant transmission power between energy storage device and healthy output terminal. Based on normal mode and fault mode, power transmission model and zero-voltage-switch (ZVS) operation boundaries of all switches are analyzed for circuit parameters design. Meanwhile the control strategies under two kinds of working modes are analyzed respectfully based on the dynamic characteristics. Finally, performance of the proposed fault reconfiguration method has been tested with the laboratory prototype to demonstrate reliability and flexibility of the converter system.