Self-reliant feature in DC-DC converters for open circuit faults

Abstract

With vast applications of dc-dc converters in grids and micro grids, the need of a vigorous converter with fault tolerant capability becomes very important. Dual active bridge (DAB) and series resonant converters (SRC) are extensively used in smart transformers. Hence the fault tolerant feature is a must in such converters in order to maintain a continuous operation with voltage and power regulation. This paper proposes the analysis of single or two switch open circuit fault on primary and secondary side of DAB and SRC. The self-reliant nature of converter in achieving fault tolerance with the help of phase shift between its input and output side is also discussed. The proposed analysis is tested on 1kW, 250V DAB and SRC prototype. The proposed correction for open circuit fault on SRC is simulated in PLECS software.