DC-Biased Hybrid Excitation Vernier Motor MTPA Control Based on Double Signal Injection Considering Voltage Source Inverter Nonlinearity

This article proposes a dc-biased hybrid excitation vernier motor maximum torque per ampere (MTPA) control strategy based on double signal injection considering voltage source inverter (VSI) nonlinearity. First, the mathematical model of the motor considering VSI nonlinearity is derived in the rotating coordinate system. Then, the effect of neglecting higher-order derivatives of MTPA criterion is reduced by using double virtual square wave signal injection. Also, the effect of VSI nonlinearity is considered in the MTPA control of this strategy. Therefore, the proposed control strategy obtains more accurate MTPA points than that of the traditional virtual square wave signal injection. Furthermore, an iterative algorithm is used to preprocess the current vector angle to improve the dynamic response. Finally, the superiority of the control strategy is verified by simulation and experiments.