Loss Functions and Efficiency Model of Permanent Magnet Assisted Synchronous Reluctance Machine

This paper proposes a method to create the efficiency map of the Permanent Magnet (PM) assisted Synchronous Reluctance Machine (PMa-synRM). Rather than improve the classic loss models, it is proposed primarily to provide a tool to investigate the mechanism between design parameters and efficiency characteristics. Firstly, an analytic model is built to predict the flux density in airgap and electromagnetic torque. Then the loss distribution is analyzed and the parameters that have a significant impact on the losses are selected to derive loss functions. The output results with corresponding control strategies can be obtained, including the torque, speed and loss. A program to create efficiency map has been established based on the proposed method. The influence of design parameters on the loss and efficiency characteristics is studied using the loss coefficients which obtained by the proposed loss functions. Several criteria are concluded to guide the initial design toward expected efficiency characteristics. The results obtained using the proposed method are compared with Finite Elements Analysis (FEA) results, and experiment platform is also constructed to validate the proposed method.