A Hybrid Fuzzy AGC in a Competitive Electricity Environment

-This paper presents a new Hybrid Fuzzy (HF) PID type controller based on Genetic Algorithms (GA’s) for solution of the Automatic generation Control (AGC) problem in a deregulated electricity environment. In order for a fuzzy rule based control system to perform well, the fuzzy sets must be carefully designed. A major problem plaguing the effective use of this method is the difficulty of accurately constructing the membership functions, because it is a computationally expensive combinatorial optimization problem. On the other hand, GAs is a technique that emulates biological evolutionary theories to solve complex optimization problems by using directed random searches to derive a set of optimal solutions. For this reason, the membership functions are tuned automatically using a modified GA’s based on the hill climbing method. The motivation for using the modified GA’s is to reduce fuzzy system effort and take large parametric uncertainties into account. The global optimum value is guaranteed using the proposed method and the speed of the algorithm’s convergence is extremely improved, too. This newly developed control strategy combines the advantage of GA’s and fuzzy system control techniques and leads to a flexible controller with simple stricture that is easy to implement. The proposed GA based HF (GAHF) controller is tested on a threearea deregulated power system under different operating conditions and contract variations. The results of the proposed GAHF controller are compared with those of Multi Stage Fuzzy (MSF) controller, robust mixed H2/H and classical PID controllers through some performance indices to illustrate its robust performance for a wide range of system parameters and load changes. Keywords--AGC, Hybrid Fuzzy Controller, Deregulated Power System, Power System Control, GAs.