Fault-Tolerant Multiport Single Diode Bridge for Distributed PV Power Collection and Voltage Step-up

In this paper, a fault-tolerant Multiport Single Diode Bridge (MSDB) converter is proposed for distributed photovoltaic collection and DC voltage step-up. During normal operation, with consideration of the varying PV output power, the converter achieves regulation under different input powers with inner bridge phase-shift modulation. The power transfer capacity and soft-switching operation region under the normal operation mode are analyzed. When a short-circuit fault occurs at certain DC PV port, the fault port isolation and non-fault port reconfiguration are realized through the modulation strategy. The proposed topology is compared with the traditional parallel and series topology in terms of cost, volume, and power loss. Both normal operation and fault reconfiguration are tested through simulation and experimental results, in verification of the proposed topology and modulation methods.