An Open-Circuit Switch Fault Detection Strategy for a Three-Stage Cascaded Boost Converter

This paper proposes a fault detection technique for a three-stage cascaded boost converter with open-circuit switch fault occurrence. The proposed fault detection algorithm is based on the behavior investigation of the three-stage cascaded boost converter under normal and fault operating conditions. The PI controller with one outer voltage loop and two inner current loops is employed to control the operation of the converter under both healthy and faulty modes. The slopes of two inductor currents and two controlled signals generated by the current loops of the PI controller are applied to the proposed fault detection strategy in order to identify the faulted switch. There is no additional sensor needed for fault detection. The simulation results are shown to validate the effectiveness of the proposed fault detection technique under different open-circuit switch fault operating conditions.