Generalized Predictive Current Control for Dual-Three-Phase PMSM to Achieve Torque Enhancement Through Harmonic Injection

The output torque capability of a dual-three-phase permanent magnet synchronous machine (DTP-PMSM) can be increased by intentionally injecting proper harmonic currents, which can be beneficial in some applications that require high torque density. To achieve this, current references containing multiple harmonic components with time-varying frequencies must be accurately tracked by the current controllers, which can hardly be achieved by conventional control methods. Fortunately, to track these complex but predetermined current references, generalized predictive control (GPC) shows unique advantages for its characteristics of multistep prediction and receding horizon optimization. In this article, a current control strategy based on GPC is proposed for the DTP-PMSM, which enhances the output torque capability by tracking the harmonic current references with high accuracy in both phase and magnitude. Parameter tuning and model mismatch issues of the proposed GPC are discussed. The effectiveness and merits of the proposed control strategy are validated by a comparison study based on simulation and experiments.