Hybrid MPC–Third‐Order Sliding Mode Control With MRAS for Fault‐Tolerant Speed Regulation of PMSMs Under Sensor Failures

This study proposes an advanced hybrid fault-tolerant control (FTC) architecture for permanent magnet synchronous motors (PMSMs) operating under speed sensor faults (SSFs), integrating model predictive control (MPC), third-order sliding mode control (TOR-SMC), and a model reference adaptive system (MRAS). The key innovation lies in the synergistic combination of MPC’s predictive optimization with the robustness of TOR-SMC and the real-time adaptive estimation capability of MRAS, enabling reliable operation in the presence of sensor degradation or failure. A residual-based fault detection mechanism is embedded to monitor discrepancies between actual and estimated rotor speeds, enabling rapid fault identification and seamless transition to observer-based control. The proposed hybrid control system is designed within a hierarchical architecture, wherein MPC optimizes inverter switching actions, TOR-SMC ensures robust disturbance rejection and chattering suppression, and MRAS delivers high-fidelity speed estimation. Simulation studies under various operating scenarios—encompassing step changes in speed, variable torque loads, and fault scenarios—demonstrate that the system achieves a maximum speed estimation error of 1.8%, speed tracking accuracy of 97.6%, and a fault detection time of less than 2.5 ms, which is 41.3% faster than extended Kalman filter (EKF)–based schemes. Quantitatively, the proposed method reduces torque ripples by 32.5%, current overshoot by 35.7%, and transient response time by 27%, while improving overall fault tolerance by 63% compared to conventional FTC approaches. The TOR-SMC module contributes to a 78% reduction in chattering and ensures stable electromagnetic torque behavior even under dynamic torque disturbances. In parallel, MRAS offers faster convergence (2.5 ms) and smoother transitions compared to SMO and EKF observers, maintaining control integrity despite sensor anomalies. This comprehensive and modular FTC approach addresses a critical vulnerability in PMSM drive systems and is particularly well-suited for deployment in electric vehicles, aerospace systems, and renewable energy platforms, where high reliability, real-time responsiveness, and robustness to sensor degradation are paramount. The results confirm the proposed hybrid MPC–TOR-SMC–MRAS framework as a scalable and high-performance solution for next-generation motor control systems under fault-prone​ environments.