Analytic Model of Copper AC Loss of Permanent Magnet Synchronous Motor with Considering Conductor Gap

For the permanent magnet synchronous motor (PMSM) with complex slot structure, the copper AC loss caused by high-frequency excitation can not be ignored, but it takes a lot of time to establish accurate model using the finite element method. In this paper, an analytic model of copper AC loss of PMSM with considering conductor gap is proposed. This model can quickly calculate the loss when the winding or slot structure size changes, and is applicable to different windings and slot types. First, according to the conductor layer, the area in slot is divided into conductor part and air part. Then, the magnetic field diffusion equations and boundary conditions are established according to the slot structure to solve the conductor current density and to calculate the loss. The current density distribution and the AC loss results obtained by using the analytic model are highly consistent with the finite element results. Therefore, the analytic model is of great significance for calculating of copper AC loss, and can provide reference value for motor design.