Adaptive Super-Twisting Sliding Mode Control of Microgrid Based on Fixed-Time Sliding Mode Observer

Abstract

Describing the networked inverter in an AC microgrid as a multi-intelligent system and considering the voltage restoration problem as a tracking problem, a finite-time quadratic control strategy for microgrid voltages considering cyber-attacks is proposed. Aiming at the false data injection attacks occurring in the microgrid actuators, a fixed-time sliding mode observer is designed, which can quickly and accurately estimate the attack signals without considering the initial conditions of the system. Then the super-twisting sliding mode is improved, and an adaptive super-twisting sliding mode is proposed. It is used to design secondary controller to solve the bias problem arising from the droop control, and realises the finite-time control. Furthermore, through the adaptive adjust of gains, the chattering problem is suppressed in the sliding mode control. The estimation value of the attack signal is introduced into the designed controller, which achieves the fast compensation of the unknown attack signal. Strict stability proofs of the observer and controller are given in this paper. Simulation experiments verify the effectiveness of the proposed scheme.