A Comprehensive Review of Fractional-Order Control Strategies for Permanent Magnet Synchronous Motors

Permanent Magnet Synchronous Motors (PMSMs) are widely used in high-performance applications due to their superior efficiency, high power density, and precise control capabilities. However, the complex nonlinear dynamics and parameter sensitivities of PMSMs present significant challenges for traditional control strategies. In recent years, fractional-order control (FOC) methods have emerged as powerful alternatives, offering enhanced flexibility and robustness by extending classical integer-order calculus to non-integer (fractional) domains. This paper presents a comprehensive review of fractional-order control strategies applied to PMSM systems. The review encompasses a detailed analysis of various FOC techniques, including Fractional-Order Proportional-Integral-Derivative (FOPID) controllers, sliding mode controllers, and adaptive fractional controllers. Key performance metrics such as torque ripple reduction, speed regulation, disturbance rejection, and energy efficiency are discussed in the context of fractional-order implementations. Furthermore, the paper explores recent trends in hybrid and intelligent control approaches that integrate fractional-order modeling with artificial intelligence and optimization algorithms. Challenges in real-time implementation, tuning complexity, and computational cost are also addressed. This review aims to provide researchers and practitioners with critical insights into the current state and future potential of fractional-order control for PMSM drives.