Multi-objective optimal allocation of capacitors to minimize installation cost and power loss and improve voltage profile, by optimal control of fuzzy parameters

Abstract

Every year, the load growth in distribution networks causes various challenges such as voltage drop. Since some of these challenges are due to the lack of reactive power sources, these problems can be solved by installing reactive power resources such as capacitors. On the other hand, considering that the installation of capacitors in the network based on one or more hours of the study period (due to the impracticality of carrying out load flow studies in all the hours of the multi-year study period) caused to over investment in capacitors and becomes uneconomical, a solution should be provided in order to optimally allocate these resources based on all the hours of the multi-year study period. Therefore, in order to solve the problem raised and in order to rationally allocate reactive power compensation devices in distribution networks, a method based on fuzzy logic is developed in this paper to take into account the amount of network load in all hours of the study period and at the same time the execution of simulations be very short in order to solve such problems. Hence, in this paper, as the first contribution, the considered problem has been solved using the method based on standard fuzzy logic, taking into account all the hours of the study period, and then as the second contribution, the optimization of the parameters of the fuzzy membership functions has been discussed, and the proposed method has been upgraded. The simulation results showed that the developed method has sufficient efficiency and it can be used to optimally allocate capacitors in the network by considering all the hours of the study period. Also, the developed method was able to improve the objective functions to a greater extent by optimally setting the parameters of the fuzzy membership functions. Optimizing the parameters of the fuzzy membership functions made the objective function of the total costs to be improved by 0.8, 1.9 and 2.5 percent by installing one, two and three capacitors, respectively. Also, this optimization caused the objective function of voltage profile to improve by 0.4, 0.7, and 1.2 percent, respectively, by installing one, two, and three capacitors.