New Circuit Topology for Fault Tolerant H-Bridge DC-DC Converter

This paper describes a new design for a fault tolerant H-bridge dc-dc converter. Fault tolerance is achieved using a multilevel converter topology in combination with a pulsewidth modulation control strategy allowing a large set of converter switching states to produce bidirectional power flows at any required output voltage. For a given converter open-circuit or short-circuit fault, all potential switch combinations are compared in terms of converter losses and output voltage harmonics to identify the most suitable switching combinations to achieve the prefault output voltage level. The fault tolerant ability of the proposed converter to recover the required output voltage is verified by both computer simulations and experimentally using a 1 kW laboratory set.