Super-Twisting Second-Order Sliding Mode Control of a Wind Turbine Coupled to a Permanent Magnet Synchronous Generator

Abstract

This paper presents a modelling study and focuses on an advanced higher order slip mode control strategy (Super Twisting Algorithm) for a variable speed wind turbine based on a permanent magnet synchronous generator to capture the maximum possible wind power from the turbine while simultaneously reducing the effect of mechanical stress, powered by a voltage inverter and controlled by vector PWM technique. This paper presents first and second order sliding mode control schemes. On the other hand, a challenging matter of pure SMC of order one can be summed up in the produced chattering phenomenon. In this work, this issue has been mitigated by implementing a new control. The proposed control, characterized by a precision in the case of a continuation of a significant reduction of the interference phenomenon, successfully addresses the problems of essential non-linearity of wind turbine systems. This type of control strategy presents more advanced performances such as behaviour without chattering (no additional mechanical stress), excellent convergence time, robustness in relation to external disturbances (faults in the network) and to non-modelled dynamics (generator and turbine) which have been widely used in power system applications by first order sliding mode control. In particular, second-order sliding regime control algorithms will be applied to the PMSG to ensure excellent dynamic performance. The suggested control is compared to the proportional-integral controller and sliding mode control of order one. The results of simulations under turbulent wind speed and parameter variations show the efficiency, robustness and significantly improved performance of the proposed control approach to distinguish and track quickly (about 10ms depending on the shading pattern) and at the same time saving the main priorities of the sliding mode of order one by reducing the existing chatter. The systems performances were tested and compared using Matlab/Simulink Software.