Load Frequency Control of Two Area Hydro-Thermal System considering GRCs and GDB Non Linearity’s with Intelligent Controller

Abstract

This paper focuses on design and development of intelligent based optimal secondary controller which could sustain with system dynamic conditions to maintain frequency and tie-line power exchange with in specified limits. For analysis purpose, a two area interconnected system comprising of thermal and hydro units in each area with system non linearity’s like generation rate constraints (GRC) and governor dead band theory (GDB) are considered to get more practical approach. System frequency and tie-line variations are observed in MATLAB/ SIMULINK platform for 1% step load perturbation (SLP) in area-1. Proportional- integral (PI), proportional-integral-derivative (PID) and Fuzzy-PID controllers are employed as secondary controllers one at a time, whose gains are optimized with Grey wolf optimization (GWO) algorithm. Later, the system dynamic responses are investigated by incorporating superconducting magnetic energy storage devices (SMES) in both areas and static synchronous series compensator (SSSC) placed in series with the tie-line. Investigation reveals the superiority of fuzzy controller with coordinated performance of SMES and SSSC in mitigating frequency deviations and tie-line power variations. Finally, sensitivity analysis is carried out to test robustness of proposed coordinated control scheme.