A Novel MTPA Control Strategy for IPMSM Drives by Space Vector Signal Injection

This paper presents an online maximum torque per ampere (MTPA) control strategy for interior permanent magnet synchronous motor (IPMSM) drives based on a space vector signal injection (SVSI) method. The key of the proposed method is that the high-frequency signal is injected into the space vector directly. Then, the MTPA operational point is analyzed by the variation in the stator flux linkage amplitude and stator current magnitude. Since the high-frequency signal is injected into the voltage space vector, there is no need to consider the bandwidth of the speed loop and current loop for the frequency selection of the injection signal. In addition, the SVSI method is easy to realize because the injected signal does not need to be modulated. This method can track the MTPA points accurately and it is parameters-independent. The effectiveness of the proposed method is verified by simulation and experimental results under various operation conditions.