Reducing Net VSI In Power System By Using Self Adaptive Firefly Algorithm

Economic Load Dispatch (ELD) seeks the best generation schedule for the generating plants to supply the required demand plus transmission loss with the minimum generation cost. Significant economical benefits can be achieved by finding a better solution to the ELD problem. Present day power systems have the problem of deciding how best to meet the varying power demand that has a daily and weekly cycle in order to maintain a high degree of economy and reliability. Among the options that are available for an engineer in choosing how to operate the system, economic load dispatch (ELD) is the most significant.ELD is a computational process whereby the total required generation is distributed among the generating units in operation so as to minimize the total generation cost, subject to load and operational constraints. The objective of ELD is to minimize the total generation cost of a power system for a given load while satisfying various constraints [1]. Over the years numerous methods with various degrees of near-optimality, efficiency, ability to handle difficult constraints and heuristics, are suggested in the literature for solving the dispatch problems. These problems are traditionally solved using mathematical programming techniques such as lambda iteration method, gradient method, linear programming, dynamic programming method and so on. Many of these methods suffer from natural complexity and converge slowly. However, the classical lambda-iteration method has been in use for a long time. The additional constraints such as line flow limits cannot be included in the lambda iteration approach and the convergence of the iterations is dependent on the initial choice of lambda. In large power systems, this method has oscillatory problems that increase the computation time [1,2]. Apart from the above methods, there is another class of numerical techniques called evolutionary search algorithms such as simulated annealing, genetic algorithms, evolutionary programming, ant colony, Artificial bee colony and particle swarm optimization have been applied in solving ELD [3-8]. Having in common processes of natural evolution, these algorithms share many similarities; each maintains a population of solutions that are evolved through random alterations and selection. The differences between these procedures lie in the representation techniques they utilize to encode candidates, the type of alterations they use to create new solutions, and the mechanism they employ for selecting the new parents. The algorithms have yielded satisfactory results across a great variety of power system problems. The Abstract: Economic Load Dispatch (ELD) is an important operational problem of the power system has been solved by by various optimization methods in the recent years, for efficient reliable power production and aiming to minimize the fuel cost. The firefly algorithm (FA), a heuristic numeric optimization algorithm inspired by the behavior of fireflies, appears to be a robust and reliable technique. This paper presents a self adaptive Firefly Algorithm for reducing sum of Voltage Stability Index(VSI) of all load buses in solution of the ELD problem. The proposed algorithm (PA) is applied to the standard IEEE 14 and 30 test systems and the results are presented to demonstrate its effectiveness.