Optimal selection of capacitors for radial distribution systems using a genetic algorithm

Voltage Profile Improvement by Capacitor Placement and Control in Unbalanced Distribution Systems Using Differential Evolution Algorithm

“…However, it has not been regarded in most of the previous works [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. On the other hand, in the methods presented in [6][7][8][9][10][11][12][13][14][15]17] the loss reduction has been accomplished only by using the fixed capacitors. Moreover, in many previous methods, the medium voltage capacitors which are more expensive than low voltage ones are used [2,3,[5][6][7][8][9][10][11][12][13][14][15][16][17][18].One of the important issues in the placement of capacitors is considering the load variations of the network.…”

“…Therefore, it is useful to investigate the capacitor placement for unbalanced distribution networks [1][2][3]. However, it has not been regarded in most of the previous works [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. On the other hand, in the methods presented in [6][7][8][9][10][11][12][13][14][15]17] the loss reduction has been accomplished only by using the fixed capacitors.…”

“…More-over, capacitor placement is also advised to be done with the daily real value in the market, so that the distribution companies may be assured of its productivity. This has been taken into consideration but only in references [3,6,16].In the previous works presented by researchers, capacitor placement has been done on the basis of different techniques including: integer programming method [2], non-linear programming method [1,3], method of sensitivity analysis [12,16], method of optimization of the equal area criterion for selecting the sites of fixed capacitors [13], dynamic programming method [8], and some methods based on the experimental criteria. In these methods, in order to solve the capacitor placement problem, some assumptions have been considered on the type of the objective function and also on the type and number of problem restrictions.…”

“…These problems include: a) non-clarity of the behavior of feeders' loads, particularly domestic loads, b) complexity of distribution net-works, c) uncertainty of electric distribution companies in returning the initial capital expenditure used for capaci-tor placement and d) variety of the type of network loads. With due regard to these difficulties, in many researches made so far, some assumptions in capacitor placements have been considered to solve the problem in a more simple method [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], which have not been appealing to distribution companies, so that the losses are still high in the network. Most of the consumption loads in distribution net-works are single phase domestic loads which are unbalanced.…”

“…Moreover, in many previous methods, the medium voltage capacitors which are more expensive than low voltage ones are used [2,3,[5][6][7][8][9][10][11][12][13][14][15][16][17][18].One of the important issues in the placement of capacitors is considering the load variations of the network. In some methods of load variation has been considered at several different levels, and in some other methods [1,[6][7][8][9][10][11][12][13][14]18], it has not been considered at all, and the load has been presented in a fixed form. More-over, capacitor placement is also advised to be done with the daily real value in the market, so that the distribution companies may be assured of its productivity.…”