AGC of a multi-area hydrothermal system using thyristor controlled series capacitor

This paper presents automatic generation control (AGC) of two and three unequal area hydrothermal systems. The thermal areas of the systems are equipped with single reheat turbine and hydro area is with electric governor. Appropriate Generation Rate Constraint (GRC) has been considered in each area. System dynamics has been obtained by considering 1% step load perturbation (SLP) in area1. Performances of several classical controllers such as Integral (I), Proportional-Integral (PI), Integral-Derivative (ID), Proportional-Integral-Derivative (PID) and Integral-Double Derivative (IDD) has been evaluated and compared in systems. Firefly algorithm (FA) has been used for optimization of different parameters. Investigations reveal that IDD controller provides better dynamic than the others in both systems. In the three area system, thyristor controlled series capacitor (TCSC) have been used in tie-line. Investigations expose that using TCSC, the oscillations and peak deviations in the responses can be reduced. Simultaneous optimization of governor speed regulation parameter (R_i) and IDD controller gains with or without TCSC provides higher values of R_i, thereby leading to economic and convenient realization of Governors.