An MTPA Control Strategy for IPMSM Based on Virtual Signal Injection Considering the Inverter Nonlinearity

To achieve more accurate and fast maximum torque per ampere control (MTPA) of permanent magnet synchronous motors (PMSM), a virtual signal injection MTPA control strategy (VSIC-MTPA) based on an accurate torque model is proposed. Considering the influence of the nonlinear voltage drop of the inverter, the torque model adopted by VSIC-MTPA is theoretically derived and analyzed, and the error term of the model is analyzed. Then, the accuracy of the torque model is improved by extracting the nonlinear voltage of the inverter and observing the motor parameters in the error term, thus further improve the control accuracy of MTPA. Experimental results show that the method is effective and stable under various operating conditions.