Three-vector Model Predictive Current Control for Electric Excitation Synchronous Motor

Introduction: Traditional model predictive control (MPC) strategies for electric excitation synchronous motor (EESM) are constrained by fixed vector control directions and limited vector magnitude ranges, while only achieving deadbeat control for the quadrature axis current, leading to poor steady- and dynamic-state characteristics. These challenges necessitate a more robust approach to enhance system performance. Method: By constructing expected voltage vectors using three basic voltage vectors in each sector and employing the six synthesized expected voltage vectors from all six sectors as candidate vectors, the proposed method ensures comprehensive coverage of both direction and amplitude, thereby significantly improving system performance. The vector action time is calculated using the direct- axis current without beat method, and the quadrature-axis current is simultaneously controlled without beat, effectively reducing current ripple and improving the steady-state performance of the system. Result: The experimental results show that compared with traditional model predictive control (MPC), the control strategy proposed in this paper significantly reduces current and torque ripple. Additionally, it presents a smoother speed curve and smaller overshoot in terms of motor speed, thereby improving the dynamic response performance and control capability of the motor. Discussion: The experimental results demonstrate superior performance compared to traditional MPC, highlighting the significance of this research in advancing EESM control technologies. However, the study is limited to specific operational conditions and assumes simplified motor models, suggesting that future work should validate these findings under broader applications and more complex scenarios. Conclusion: This paper presents an innovative Three-Vector Model Predictive Current Control (TV-MPCC) strategy that overcomes the limitations of traditional methods by employing an equivalent synthesis approach for expected voltage vectors and implementing effective beat-free control of direct- and quadrature-axis currents. The proposed method enhances both system stability and performance, offering a valuable reference for future algorithmic developments in model predictive control (MPC).