Novel Circuit to Compensate the Effect of Source Open Circuit Fault in Distributed Generation System

Abstract

In this paper a novel compensating circuit, composed ofcapacitors, one IGBT switch, and a diode bridge isdesigned and employed within a SOFC distributedgeneration system connected to a micro-grid. The DGsystem consists of the FC stack, a Cuk converter, a threephase inverter, the proposed compensating circuit, andType 2 Fuzzy logic controller to adjust the output voltageto its reference value, to manage the charging of thecompensating circuit capacitors during normaloperation, and to manage the discharge of thecompensating circuit during fault to ensure thecontinuous power supply to the load during the opencircuit fault of the SOFC. A detailed description of themanaging controllers and switching sequences is alsogiven. Results proved the validity of the compensatingcircuit in supplying the load during the absence of themain source, hence preventing serious consequences ofshutting down important loads.