An active disturbance rejection sensorless control strategy based on sliding mode observer for marine current turbine

Marine current energy attracts much attention as a source of inexhaustible green energy. However, marine current turbines operate in a very harsh underwater environment, making it difficult to operate and maintain mechanical sensors. Therefore, the application of a sensorless control strategy is fully justified to improve the reliability of system electrical energy production. In this paper, an active disturbance rejection sensorless control strategy based on compensation sliding mode observer is proposed for the marine current turbine system. The proposed control method consists of two parts. The first part is to design an active disturbance rejection controller for the marine current turbine that will improve the system's anti-interference abilities. The second part proposes a time-delay compensation sliding mode observer based on the Smith predictor to conduct real-time delay compensation of the system. The entire system is ensured to be globally stable through the Lyapunov approach analysis. The proposed control strategy is verified by simulation, which can not only effectively suppress the lumped disturbance and eliminate the system time-delay, but also improve the power extraction capability of the system.