High-order sliding-mode control using integral terminal sliding manifold for a wind turbine under grid faults

Abstract

This paper deals with the design of a Novel Modified Super-Twisting sliding mode control (NMST-SMC) with an integral terminal sliding surface. The NMST-SMC algorithm was applied for a wind energy conversion system based on an induction generator. Firstly, integral terminal sliding surfaces are designed for rotor flux, voltage and current subsystems. Secondly, reaching control laws are added in the equivalent control law to enhance the tracking performance of the rotor flux, stator current, DC bus voltage and gridside current loops. To increase the system performance, a modified super-twisting controller is added. This suggested control scheme is aimed to reduce the total harmonic distortion (THD), strong robustness and stability to voltage faults, and fast dynamic response to power step change. The stability of the proposed controller is proved using the Lyapunov theory. The numerical simulation results of the proposed control strategy are compared to others to prove its effectiveness.

Keywords:

• SCIG wind turbine
• modified super-twisting sliding-mode control
• LCL filter
• grid fault voltage
• stability analysis
• Lyapunov theory