Joint Planning Based On Fuzzy Genetic Algorithm In Low Voltage Distribution Network

Our country has largely invested in reconstruction of city electric power network in past years. It strength the supply ability of high-voltage network. But there are still many problems in middle and low voltage network result from the neglect of it. In this paper problem that high power loss and bad voltage quality in distribution network is analyzed. The defect of present distribution network planning and distribution model is pointed out. A new distribution model that small capacity transformer and short low voltage line is presented after analyzing the power supply ability of distribution network. It is found that this method is better than that of past through comparison between them. The advice that the fifth item of standard DL/T559-1996 should be modified is also presented. In the past electric power planning is considered only under the same voltage level. In this paper global joint planning for middle and low voltage network is considered. Both line arrangement and cross section and transformer arrangement and rate are considered. It is a non-line combined optimum problem more complex than single network planning. Genetic algorithm is adopted to solve this problem. The method using several chromosomes express a scheme is presented. Crossover rate and mutation rate are automatically adjusted by fuzzy control to quicken search procedure and avoid immature convergence. The result of typical example shows that these measures are feasible and efficient.