Application of Robust Sliding Mode Control to Uncertain Power System Stability

Consider load frequency control of a power system with the communication delay and apply the sliding mode controller to this uncertain power system. The delay from the communication network is assumed to be constant time-delay type. The delay in two areas is assumed to be same. The modern power systems with industrial and commercial loads need to operate at constant frequency with reliable power. The goals of the LFC problem are to maintain constant frequency in a multi area interconnected power system. The time delay dependent stability analysis presented here, to ensure robust stability of uncertain time delay system is used to determine the upper bound of time delay for which the power system is robustly stable. Then the sliding surface is designed and the reaching mode control law is applied. The uncertain power system model with communication delay is controlled with two control strategies, namely 1) Equivalent Control Law and 2) State Feedback Control Law. Once the trajectories reach the surface, the control is switched to second control action.