Load frequency controller for multisource interconnected nonlinear power system incorporating FACTs devices

Abstract

The load frequency control for two area multisource interconnected power system model incorporating flexible AC transmission system (FACTs) devices is presented in this paper. The slow response of governor, the power swings and frequency oscillations tend to take longer time to settle to normal condition post disturbances. To overcome this condition, application of FACTs devices for frequency stabilisation under a small perturbation is studied and investigations are carried out on two area multisource interconnected power system model. The controller gains are tuned using genetic algorithm and the effect of FACTs devices for damping of power swings and frequency oscillations in an interconnected power system is studied and compared by the detailed analysis of power system dynamics. The power system model consists of thermal, hydro and doubly fed induction generator (DFIG)-based wind plant in each area. Governor deadband (GDB) and generation rate constraint (GRC) is also considered to study the effect of nonlinearity on the power system dynamics. It has been observed that FACTs enabled power system is very effective in damping out the power swings and local frequency oscillations caused due to disturbance in load. An improvement in the transient response and tie-line power oscillations is also quite appreciable.