Fractional Calculus Based Hybrid Controller Design for LFC Analysis

Abstract

newlineIn the modern-day power system, Load Frequency Control (LFC) has got a significant newlinerole to play. It plays a vital part in retaining the system frequencies and the interline power newlinedeviations within their planned values. In an interconnected power system, LFC mainly newlinefocuses on the regulation of system frequency and interline power between different areas. To newlineensure the proper execution of the above responsibilities it is utmost required that the net newlinepower generation and the load demands are at balance with each other. If the load demand newlinedeviates from the generation, the frequency deviation rises in the system along with a newlinevariation in the nominal power flow in the tie-line. The primary role of AGC is to keep the newlinepower flow within the scheduled value by minimizing a quantity known as the ACE (Area newlineControl Error) which in turn reduces the deviations in frequency and interline power. newlineThis research work mainly focuses on improvement of frequency stability of newlineinterconnected electrical power system by employing Artificial Intelligence (AI) techniques newlineand various controller structures. The mismatch between generation and demand leads to newlinedeviation in nominal system frequency and scheduled tie-line power flows. Load Frequency newlineControl is designed and implemented in power systems which automatically balances the load newlinedemand and generated power in each control area. The initial adjustment of frequency is newlineachieved by primary speed control loop and then fine adjustment is done by supplementary newlinecontroller which resets the frequency error to zero through the combined action of Integral (I) newline/ Proportional-Integral (PI) / Proportional-Integral-Derivative (PID) controller. Therefore newlineperformance of LFC mainly depends on suitable gains of I/PI/PID controller. newlineInitially an attempt has been made for the optimal design of PID, Fractional order PID newline(FOPID), Fuzzy-PID (FPID) and Fractional order Fuzzy-PID (FOFPID) controllers newlineemploying symbiotic organisms search (SOS) algorithm for LFC of two unequal area newlineinterconnected realistic power system with diverse sources of generation consisting of a newlinethermal, hydro and wind generating unit in one area and a thermal, hydro and diesel newlinegenerating unit in other area. Thus, there is a penetration of renewable energy source i.e. wind newlineenergy in the considered model. It is witnessed that FO-FPID controller exhibits superior newlineperformance than the other controllers. At the same time, it was also verified that there is a newlinedefinite sequence of order of performance supremacy among these controllers and the newlinevii newlinecontrollers can be arranged in sequence of descending order of performance as FO-FPID,