Fault location and type identification method for current and voltage sensors in traction rectifiers

The reliability of rectifiers is regarded as one of the most important factors in traction systems. Unexpected faults occurring in sensors can degrade the performance and lead to secondary faults. Accordingly, a sensor fault diagnosis method is proposed in this paper. It can locate faults and identify fault types. Three high-incidence fault types in current and voltage sensors have been taken into consideration. Only the current residual is needed in the process of fault diagnosis. No additional sensors are required in this method. First, a traction rectifier model is developed. Then, a grid current estimator is constructed, the residual is acquired and applied to fault detection. Next, the residual is analyzed under different kinds of sensor faults. Fault diagnosis functions are constructed and the faults can be diagnosed. Finally, an experiment test is processed to demonstrate the effectiveness of the proposed method.