A Maximum Torque Per Loss Control Strategy for IPMSM Drive System Based on Torque Closed-Loop

For efficiency optimization of an interior permanent magnet synchronous motor (IPMSM) drive system, an adaptive maximum torque per loss control strategy based on historical data-assisted online extremum seeking is proposed. First, a comprehensive loss model of the system is established, and the nonlinear relationship between system efficiency and current angle under constant torque conditions is analyzed. Then, an estimation method for iron loss and system efficiency based on search coils is proposed, which effectively reduces dependence on motor models and parameters. Subsequently, an extremum-seeking framework based on a proportional-integral-resonant controller is developed to achieve optimal system efficiency under torque closed-loop control. Furthermore, a historical data-assisted hybrid optimization strategy is proposed to shorten search time. This method achieves adaptive system efficiency optimization and significantly improves response performance under dynamic operating conditions. Finally, the effectiveness of the proposed method is validated on a 21-kW IPMSM drive system.