Design and experimental validation of enhanced adaptive second-order SMC for PMSG-based wind energy conversion system

This paper presents Adaptive Second-Order Sliding Mode Control (SOSMC) for power control of Permanent Magnet Synchronous Generator (PMSG). The control objective is to force the PMSG to generate the desired power through regulating the winding current. Specifically, Super Twisting (ST) algorithm SOSMC is adopted in this paper to derive a robust and fast current control for PMSG-based Wind Energy Conversion System (WECS). ST algorithm is renowned for its robustness against parametric uncertainty and external disturbance, but it suffers from the chattering problem. The existing Adaptive Super Twisting (AST) algorithm can reduce the chattering effect, but often at the expense of degraded transient response. In this work, an alternative way is proposed to implement AST algorithm in order to achieve fast transient response, while at the same time attenuate the chattering problem. The controller performance is validated through an experimental setup consisting of a wind turbine emulator and a PMSG which is connected to the grid via back-to-back converter. The experimental results show better performance of the closed-loop system in terms of response time, steady-state error, and chattering despite the presence of parametric uncertainty.