Robust Deadbeat Predictive Current Control for PMSM Harmonic Torque Suppression Based on Multiloop Quasi-Resonant Observer

Although permanent magnet synchronous motors (PMSMs) offer high efficiency and power density, their performance is often compromised by inherent harmonic currents and torque pulsations, limiting applicability in high-precision motion control. While conventional deadbeat predictive current control (DPCC) improves dynamic response and control performance, it fails to mitigate harmonic-induced vibration due to their limited observation capability for high-frequency disturbances. To address these challenges, this paper proposes a harmonic-suppression DPCC (HS-DPCC) with a decoupled compensation structure. First, a parameter‑robust extended state observer (PR‑ESO) is designed to actively estimate and compensate for low‑frequency disturbances caused by parameter variations. Second, parallel multi‑loop quasi‑resonant controllers (QRCs) are embedded in both the current and speed loops to provide high gain at targeted harmonic frequencies, enabling precise cancellation of periodic torque harmonics. Electromechanical simulations and experiments validate the proposed approach, demonstrating significant harmonic suppression and robust performance. The results confirm its potential for high-precision, low-vibration motion control applications.