In trying to solve multiobjective optimization problems, many traditional methods scalarize the objective vector into a single objective. In those cases, the obtained solution is highly sensitive to the weight vector used in the scalarization process and demands that the user have knowledge about the underlying problem. Moreover, in solving multiobjective problems, designers may be interested in a set of Pareto-optimal points, instead of a single point. Since genetic algorithms (GAs) work with a population of points, it seems natural to use GAs in multiobjective optimization problems to capture a number of solutions simultaneously. Although a vector evaluated GA (VEGA) has been implemented by Schaffer and has been tried to solve a number of multiobjective problems, the algorithm seems to have bias toward some regions. In this paper, we investigate Goldberg's notion of nondominated sorting in GAs along with a niche and speciation method to find multiple Pareto-optimal points simultaneously. The proof-of-principle results obtained on three problems used by Schaffer and others suggest that the proposed method can be extended to higher dimensional and more difficult multiobjective problems. A number of suggestions for extension and application of the algorithm are also discussed.

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This paper deals with the power system operation, frequency error and voltage control problems. In actual power system operations the load is changing continuously and randomly. As the ability of the generation to trace the change in load is limited due to physical/technical considerations. They result an imbalance between actual and the scheduled generation quantities. This imbalance leads to a frequency error and voltage problems. In general, as the speed of the machine depends on the frequency, any deviation in the frequency may lead to mal-operation of the system. So load frequency control is the key problem in the power system. For specified power rating of the machine the voltage should maintain constant otherwise the system insulation may get damage. In modern power system multi area inter connected systems are used for more reliability and economic purpose. In the multi area inter connected systems the frequency errors and voltage problems can be effectively decreased by using fuzzy logic controller with either of the 3, 5 or 7 membership functions. Here this fuzzy logic controller action also compared with automatic generation control and PI controllers also. By using fuzzy logic controller the frequency error, settling time, peak overshoot, under overshoots are effectively reduced.

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