A Robust Unified Strategy for Maximum Torque Per Ampere and Field Weakening in Permanent Magnet Synchronous Motor

The intricate control structure and demanding preparations undeniably make the high precision and performance realization of maximum torque per ampere (MTPA) and field weakening (FW) strategies challenging in the permanent magnet synchronous motor (PMSM). This paper proposes a straightforward yet potent strategy to surmount this challenge. By redefining the whole control process as a convex optimization and employing the indicator function to approximate constraints, the MTPA-FW control is seamlessly realized through the calculation of a single equation online, obviating the requirement for any supplementary operation. Meanwhile, a model correction method based on the moving horizon estimator is designed to mitigate the impact of parameter variation and enhance the calculation accuracy. The experimental results have proved the superiority of the proposed strategy.