MRAS and LADRC Based Sensorless Control of PMSM with High Speed and Low Carrier Ratio

The widespread application of Permanent Magnet Synchronous Motors (PMSM) in Unmanned Aerial Vehicle (UAV) systems for power supply to the onboard equipment creates a critical need for stable operation under high-speed and low-carrier-ratio scenarios. This situation has a bad impact on system sensitivity and fast response, and the methods under low speeds perform poorly at high speeds. Currently, the conventional PI control method is commonly used. Meanwhile, considering the extreme working environment and complex and harsh working conditions of UAVs, it is necessary to apply sensorless control strategies to PMSMs and explore other methods that can replace conventional PI control. This paper proposed a novel sensorless control framework for PMSMs operating under high-speed, low-carrier-ratio conditions. The proposed method synergistically integrates Linear Active Disturbance Rejection Control (LADRC), for its superior disturbance rejection capabilities, with a Model Reference Adaptive System (MRAS) for accurate rotor position and speed estimation. The key parameters of the LADRC are systematically determined through theoretical derivation and the principle of self-adaption in MRAS is designed. The efficacy of this integrated strategy is rigorously validated through numerical simulations. The results confirm that the proposed solution provides effective and robust control, presenting a superior power supply strategy for advanced aviation systems.