Design of power-assisted motor for vehicle air-conditioning systems

This paper proposes an optimal design process for a 1.26 kW power-assisted permanent magnet synchronous motor (PMSM) for a vehicle air-conditioning (A/C) system. The PMSM specifications are based on traditional vehicle compressor products. The preliminary design stage involved determination of the motor type, winding type and number of slots and poles. The energy method was then used to construct a 2D magnetic circuit model of the power-assisted motor. Sensitivity analysis was used to determine the most important design variables, which were selected to optimize the objective functions, including output torque, torque ripple, weight and efficiency. The optimal design was determined by combining the Multifunctional Optimization System Tool (MOST) with the 2-D magnetic circuit model. In addition, direct- and quadrature-axis inductances were calculated to prove that the saliency of the half-inset magnet rotor configuration is greater than unity.