High frequency model of interior permanent magnet motor for EMI analysis

The interior permanent magnet (IPM) motors are widely used in electric vehicles for high torque and power density and reliable structure. As a key component in the drive system, IPM has become one of the most critical elements in the electromagnetic interference (EMI) propagation path. Different from the induction motor, the impedance curves of the IPM motor vary with the rotor position, due to the permanent magnet and the saliency effect. The paper expounds the mechanism which makes the difference between the IPM and induction motor, and analyzes the impedance characteristic of IPM motor, finally suggests a high frequency model. The abstraction of the value of the parameters has also been involved.