Research Of Reactive Power Optimization Based On Niche Genetic Algorithm

Reactive power optimization is not only a core problem of voltage stabilization and operation economically, but the most important control methods to improve the power system voltage quality and reduce the transmission loss in the power system. So studying the problem of reactive power optimization has the great significance in theory and great value in practical application.In those days, classical mathematical analysis programming methods with mature and integrated theory were used, which can obtain the final result very quickly, but unfortunately the functions must be differentiable, thus it is not easy to attain. Reactive power optimization is a large-scale nonlinear optimization problem with a large number of variables and uncertain parameters, the operating variables include continuous and discrete variables. So the optimization becomes very complex. According to the characteristics of reactive power optimization, this paper give a new improved Niche Genetic Algorithm. This algorithm draws lessons from living creature existence in the local area and environment. In this algorithm, the individual lives and evolves in a specifically environment, the population diversity can be maintained. The new algorithm resolve the problem converging to a local optimal solution because of reducing the population diversity in simple GA and being short of ability in local searching.Considering the situation that some of controllability variable in power system are consecutive and others are discrete, this paper propose the multiparameter hybria coding which including integer and real number, and the idea operating by grouping. It can Avoid the rounding error which comes from rounding operation in old ways. So the solution accord with the fact. At the same time, step of algorithm becomes clear. This paper also establishes the optimization model from comparison with hign voltage power system,and implements it by Niche Genetic Algorithm(NGA).the corresponding software which adopts the method of object oriented programming is programmed. so the program is convenient to modify, debug, all-purpose. we have adjusted the genetic operators to enhance the ability of global searching.The program was used to the IEEE 30-bus system and results proved that the method given by this paper is accurate and effective. the method has great value in theory and practice.