Decentralized PID-Based Sliding Mode Load Frequency Control Scheme in Power Systems

In this paper, a decentralized PID-sliding mode controller is designe for load frequency control (LFC) of multi-area power system with both matched as well as unmatched uncertainties. In the design of the sliding mode control approach, a PID sliding surface is considered, and based on the reaching law, a robust controller is designed to ensure that the frequency and tie-line power deviations converge to zero after different load perturbations are given in each area. The required stability condition is established using Lyapunov's stability theorem and verifies the implied controller's reliability. To validate the proposed controller design, Matlab environment is used for carrying out simulations under various conditions. The obtained results convey that the decentralized PID-sliding mode control ensures stable operation of the three area power system and can achieve the desired goal with less overshoot in finite time.