A Robust Mechanical Sensorless Control Strategy for Active Rectification of Small Wind Turbines

This article proposes a mechanical sensorless control strategy for the synchronous rectification of small wind turbines (SWTs) equipped with a surface-mounted permanent magnet synchronous generator (PMSG). By means of Lyapunov theory, the global asymptotic Stability of the closed-loop system is proven. It allows the use of a classical sliding mode observer (SMO) to remove the mechanical sensor in the control loop despite uncertainties on the resistance and inductance parameters. The analysis of the equilibrium points has made it possible to propose an analytic model of the angular misalignment between the true and the observer rotating frames, responsible for current tracking errors. Experimental tests on a wind turbine emulator (WTE) show that despite up to 100% of error on the resistance and inductance parameters, the impact on the energy production is negligible, proving that the strategy’s performance is robust to high uncertainties.