Research on position-compensation-based control strategy for permanent magnet synchronous motors

Purpose Permanent magnet synchronous motors (PMSMs) require precise rotor position for optimal vector control. However, initial position errors arise from non-ideal factors like friction and cogging torque, creating a discrepancy between the actual and measured positions. This paper aims to analyze these errors and proposes a compensation strategy to improve performance. Design/methodology/approach To address this challenge, the authors first rigorously analyze the generation mechanism of initial position errors through theoretical modeling. And the authors investigate the influence of rotor position error on motor speed and motor losses. Furthermore, the authors analyze the magnitude of the error limit and its influencing factors. Subsequently, the authors develop a novel position-compensation-based control strategy. This method enable precise alignment of the rotor position before motor startup. The proposed position compensation method is validated through both high-fidelity simulations and experimental tests, comparing performance metrics against conventional compensation method. Findings The results demonstrate that the PMSM control system using the proposed rotor position compensation strategy has improved the motor speed response, significantly reduced the stator current amplitude at the same time, thereby achieving a substantial decrease in copper loss. Compared with conventional methods, it achieves a 10% increase in rotational speed and a reduction of more than 15% in current amplitude. Originality/value This study systematically clarifies the generation mechanism of initial position errors and their impact on system performance. Based on this, the proposed position compensation method effectively resolves the position error issues caused by non-ideal factors, achieving a coordinated optimization of control performance and energy efficiency and holds significant engineering application value.