Adaptive robust-sliding mode control strategy for improving stability of interconnected power system with virtual inertia of wind farm

Under the background of large-scale integration of renewable energy represented by wind power into the traditional power system, the coupling effect of non-synchronous generator source and synchronous generator source and the uncertainty of wind power output make the stability control of interconnected power system face complex operation scenarios. Aiming at this problem, an equivalent rotor motion model of synchronous generator considering the effect of virtual inertia of wind turbine is built based on the principle of power balance, and the system parameter coordination and fault factors are expressed as equivalent inertia parameter perturbation and bounded uncertain disturbance. Using sliding mode variable structure method, combined with the variability and controllability of equivalent inertia and equivalent damping, an AR-SMC (Adaptive Robust-Sliding Mode Control) strategy is proposed to improve the dynamic stability of interconnected power system. The theoretical analysis and simulative results show that, compared with the traditional virtual inertia control method, the proposed control strategy can better suppress frequency oscillation and reduce the rate of change of frequency and relative power angle oscillation amplitude. © 2020, Electric Power Automation Equipment Press. All right reserved.