Nonlinear Integral Sliding Mode Secondary Control of DC Microgrid Considering Network Attack

Aiming at the problem that the secondary control of DC microgrid is vulnerable to external false data injection attacks, which affects the stability of the system, a composite control scheme combining extended sliding mode observer and nonlinear integral sliding mode controller is proposed. The novelty: A new extended sliding mode attack observer is designed to detect attacks in real time. A new secondary controller is designed which can not only compensate the attack using the estimated attack signals by the new observer, but also realize the consistent control based on multi-agent method. The new secondary controller uses nonlinear sliding surface method to solve the contradiction between the chattering of system and the approaching time of sliding surface, further improving the anti-attack ability and control quality of the controller. The steady-state error of voltage caused by FDI attack is eliminated, and the secondary recovery of bus voltage and proportional distribution of load are realized. The proof of stability and the analysis of finite-time convergence are given. The simulation results show that the proposed controller can achieve the established goals of voltage stability and load proportional distribution under the conditions of false data attack, load change, communication interruption, etc., and has strong robustness and good dynamic performance .