A Single Area Load Frequency Control (LFC): Comparative Study Based on Integral and Fuzzy Logic Controller
Abstract: The comparative analysis of integral and fuzzy logic controller for load frequency control has been described in this paper. Local feedback signal from the output to the input has been injected to the controller. A single area power system is simulated to validate the effectiveness of the controller. The effect of system nonlinearity such as Generation Rate Constraint (GRC) and Governor Dead Band has been studied. Simulation has been carried out using MATLAB/ Simulink 2009.
Keyword: Load frequency control, fuzzy logic, dead band.
I. INTRODUCTION
For the constancy of system frequency to a fine tolerance level to match the system generation with system load is important task. A system load change causes the change in the speed of Turbine-Generator rotor system. For stabilizing the system frequency Primary control action of the governor control has been initiated. To regulate system frequency to the set nominal value is the primary objective of automatic generation control (AGC). So, Supplementary control action is required to restore frequency to nominal value and also it regulates the net interchange of interconnected power system for the reliability and quality of power supply [1]. Power system nonlinearities (Generation rate constraints (GRC) and governor dead bands) in a single area power system is shown in Fig.1 The operating point of a power system often changes on daily cycle basis . Also, a fixed controller may no longer be suitable [3]. The loading in a power system is never constant. Using fuzzy logic controller stability of a large electric power system can be enhanced [1]. Due to the influence of the control system the dynamic performance of power systems are usually affected by the [4]. To obtain an accurate linear time-invariant models at various point and it is quite difficult [1].Normally, Control feed back as an area control error (ACE) is use as a feedback control through integral controller Optimal control using full state feedback is described in [5].