PROTECTION OF MOTOR DRIVE SYSTEMS FROM CURRENT SENSOR FAULTS

摘要

Methods and apparatus are provided for detecting a phase current sensor fault in a multi-phase electrical motor. The method comprises, receiving an input torque command T* and measuring a set of feedback signals of the motor including a phase current Ix for each of the phases of the motor, generating direct and quadrature command phase currents Id*, Iq* for the motor corresponding to a value of the input torque command T*, determining a total command current Is=[(Iq*)2+(Id*)2]½, generating a negative sequence current Ineg, where for three phases Ineg=(⅓)[Ia+(α2)Ib+(α)Ic], where α=ej2π/3, combining Ineg and Is to provide a normalized negative sequence current Inn=Ineg/Is, comparing the normalized negative sequence current Inn to a predetermined threshold value INN* to determine the presence of a phase current sensor fault, and executing a control action when InnINN*.