Efficiency Optimization Control of the Axial Field Flux-Switching Permanent Magnet Motor Based on a Loss Model

Axial Field Flux-Switching Permanent Magnet Motor (AFFSPMM) is favored for new energy vehicles because of large torque at low speeds and saving space. However, the significant harmonic contents in AFFSPMM inevitably lead to the losses increase while improving the output torque, so the efficiency optimization control methods are investigated to enhance the efficiency for satisfying the requirement of energy conservation. In order to reduce losses and enhance the efficiency of AFFSPMM, the optimization control strategy based on loss model is developed and investigated for AFFSPMM. Firstly, the loss model of the copper losses, iron losses, and permanent magnet eddy current losses are developed and built for the AFFSPMM by the analytical and experimental method. Then, these parameters of inductance, resistance, and magnetic flux during the motor’s operation are identified and estimated through the recursive least squares method with updated forgetting factors to improve the accuracy of the loss model. Finally, based on loss models, the d-axis and q-axis currents are calculated and redistributed in order to minimize the loss of AFFSPMM, so that improving the operational efficiency of the motor. In addition, the experiments are done to verify the proposed control method and it is compared with the control method of id =0, Maximum Torque Per Ampere (MTPA) and Loss Minimization Control (LMC). The results indicate the proposed control method has better dynamic performance, and can achieve the highest efficiency compared with the three control methods.