Research On Fault Diagnosis And Fault Tolerant Control Of Electric Motor Drive System In Hev

As one critical component of HEV, the electric motor drive system has a close relation with the whole vehicle performance. As high as possible reliability of electric motor drive system in HEV is required. Therefore the diagnosis and elimination of faults must be also accuracy, reliable and quick. For HEV in the elementary development stage, since the power train faults appear more frequently, the fault-tolerant control becomes more and more important.This paper takes the electric motor drive in HEV as research object, and focus on the diagnosis of motor and motor controller and fault tolerance of the electric motor drive in HEV.For the motor and the controller in HEV, the fault modes and fault mechanisms of the motor and the controller are analyzed. Then the fault tree of electric motor drive system is built and analyzed.Based on Finite-element model of permanent magnet synchronous motor, partial demagnetization fault and short circuit fault of the stator interturn are investigated, and the methods of the fault diagnosis are summarized by analyzing the fault characteristic.The power switch drive open circuit faults are analyzed, and fault model in Matlab/simulink is built. According to the analysis of fault current, fault diagnosis evidence is summed up. Based on the particularity of the electric motor drive system, detection and protection circuit is designed. Moreover the suitable fault-tolerant strategies to the possible faults of electric motor drive system in HEV.The fault current in the bench test is analyzed, fault feature and the method of diagnosis is achieved.