Switch Short-Circuit Fault Detection Algorithm based on Drain-to-Source Voltage Monitoring for a Fault Tolerant DC/DC Converter

Switch Short-Circuit Fault (SSCF) is one of the most harmful failure mode in a DC-DC Converter. As a consequence, the earliest identification should be ensured in order to avoid the shutdown of the whole system. In this paper, a fast and simple method is introduced for detecting and identifying the faulty leg caused by a SSCF in a six-phase Interleaved Boost Converter (IBC) for Fuel Cell Vehicle application. The proposed detection technique is based on a comparison between the power MOSFET Drain-to-Source Voltage VDS in ON state with an adjustable threshold voltage VDS-ON-TH by using only control pulses and driver information. After the fault detection, and its isolation, remedial actions by control reconfiguration methodology are applied to allow the DC-DC converter to operate in pre-fault conditions. To confirm the effectiveness of the suggested approach, simulation tests are reported using Matlab/Simulink (c) and ANSYS/Simplorer (c). Also, comparative study between the developed voltage-based method and current-based method is provided by numerical simulations. The results obtained by the proposed method indicate that the SSCF can be detected not only in switch ON state but also in OFF state by adding some modifications to the proposed algorithm. In switch OFF state, the results prove similar behavior detection time for both the methods which detects fault occurrence in less than one switching period. By contrast, for the ON state, the proposed method detects the failure for a 100 kHz frequency using the voltage information provided by the driver. The advantage of this method is that the detections are valid in both states (ON and OFF), the suggested algorithm is simple, and easily configurable.