Five-Level T-type Converter Based Fault-Tolerant Isolated Dc-Dc Topology Using WBG Devices

In this paper, a bidirectional isolated dc-dc converter is proposed for MVDC applications. In this topology, a modified T-type converter producing a 5-level voltage waveform is used on both sides of a high frequency transformer. The operations of the proposed converter and switching strategies in normal and faulty conditions are investigated in detail. A cost function is used to minimize the overall losses of the converter. The proposed converter has advantages of better fault-tolerance and higher efficiency compared to common dual active bridge dc-dc converters. The operation of the proposed structure is verified by experimental results.