The Application of Optimum Self-Tuning Fuzzy Logic Controllers in Multi-Area Power Systems Including UPFC

In this paper, self-tuning fuzzy logic controllers have been designed for load frequency control of power systems using the integral of time-absolute error (ITAE) and integral of time multiply squared error (ITSE) as optimization criteria and the maximum of area control error (ACE) as error signal. The optimal control parameters are obtained using the teaching–learning-based optimization algorithm which has a high accuracy and a high convergence speed. All simulations and coding were done MATLAB software in order to optimize the design of the controller. The effectiveness of the proposed method was shown on a two-area three-power plant power system under area load disturbances. After evaluating and comparing the performance of the optimized controller with the non-optimized controller, it was concluded that the optimized self-tuning fuzzy logic controller (OSTFLC) has a better and more robust performance than a STFLC in a wide range of electrical load variations occurred in both areas. To reach the above mentioned goal, optimization of the membership function, error and it’s derivative are done simultaneously. At the, same time the fuzzy PID controller and UPFC system parameters are also optimized, through the use of TLBO algorithm. An optimal control system and an optimal modelling of the system are the main contributions of this paper.