On design of a robust decentralized controller for an interconnected multi-area power system with FACTS devices

Abstract

In this article, a robust active disturbance rejection control (ADRC) is proposed for load frequency control (LFC) of an interconnected multi-area power system. Two widely employed test systems, namely, two-areas and four-areas hydro-thermal power utilities are concerned to validate the efficacy of the suggested method. To enhance the performance of the system, series flexible ac transmission system (FACTS) like thyristor controlled series compensator (TCSC) and thyristor controlled phase shifter (TCPS) are considered. The simulation results indicated that the system performance is improved with the inclusion of FACTS devices. The adjustable parameters of the proposed FACTS controllers are optimized using particle swarm optimization (PSO) algorithm employing an Integral of Time multiplied Absolute Error (ITAE) criterion. The investigations showed  that the proposed controller provides better dynamic performance than others from the point of view of settling time, peak over/undershoot. Finally, the sensitivity analysis of the system is inspected by varying the system parameters and operating load conditions from their pre-specified values. It is observed that the suggested controller based optimization algorithm is robust and performs satisfactorily with the variations in operating load conditions, system parameters and load patterns.