Cyber-physical robust control framework for enhancing transient stability of smart grids

Abstract

Transient stability of power systems has become even more critical due to increasing complexity created by large penetration of renewable energy sources and massive deployment of information and communication technology. Fortunately, the two-way real-time data exchange capacity of smart grids allows designing advanced digital control schemes to better address the power system stability. In this study, a non-linear model-free-based robust controller in conjunction with a state estimation architecture is designed to enhance transient stability margins. The designed controller addresses uncertainties arising from communication and control input delay, sensor errors, varying plant parameters, and unmodelled dynamics effects. A novel time-delay compensation technique is presented in the control development to mitigate the effect of delay and the robustness of the proposed controller is proven by conducting a Lyapunov stability analysis with respect to additive disturbance and time delay. Furthermore, the proposed control framework is validated on the IEEE 39 bus test system through MATLAB simulation. The results show that the proposed framework is capable of stabilising the power system after a fault, also showing robustness to noise, latency in communication, delay in control input, and malicious data injection.

Keywords

• cyber-physical systems
• robust control
• power system stability
• smart power grids
• nonlinear control systems
• state estimation
• compensation
• delays
• Lyapunov methods
• power system control
• cyber-physical robust control framework
• smart grids
• nonlinear model-free-based control
• state estimation architecture
• transient stability margins
• time-delay compensation technique
• Lyapunov stability analysis
• additive disturbance
• IEEE 39 bus test system