A Residual-Based Open-Circuit Fault Diagnosis Approach for Voltage Source Power Converters

This work presents a residual-based open-circuit switch fault diagnosis algorithm for a two-level power converter. We analysis the impact of open-circuit faults on output voltage. The voltage residual is obtained through comparing the actual value and the predicted value of the output voltage. Thereafter, the voltage residual is transferred to current residual based on the system model. Utilizing the current residual, the proposed algorithm achieves fast diagnosis and location within several control periods. This algorithm only requires the measured and predicted values of output current, which can be obtained from the existing control system, dispensing with extra voltage sensors. Experiment results validate the effectiveness and reliability of the proposed diagnosis algorithm.