Multi fault diagnosis of traction motor current sensor based on state observer

Current sensor is the important information acquisition device of CRH2 EMU, when the current sensor appear performance degeneration, fault or failure, it will affect the performance of the system control and monitor. For this purpose, a new method of multi fault diagnosis of traction motor current sensor based on state observer for CRH2 EMU traction motor is proposed. Based on the mathematical model of traction motor, a state observer is constructed to estimate the stator side current of the motor and generate the residual error. Compare the residual and the setting threshold value to judge whether there is a fault; if there is a fault, According to the definition of residual error and construct the fault feature, By setting the integral result flag, fault analysis and fault type flag, Obtain current sensor fault location and the diagnosis of offset, shock, gain, drift and other types of fault. The simulation results verify that the proposed method has good ability of fault detection and fault diagnosis for 4 kinds of current sensors of CRH2 type EMU traction motor.