Optimal Capacitor Placement and Sizing in Distribution Networks

Utilizing capacitor banks in order for local compensation of loads reactive power is common in distribution networks. Using capacitors has positive effects on networks such as power and energy loss reduction, voltage deviation and network harmonic reduction as well as improvement in network power factor. Capacitor placement is applied on the network in a form of single or multi-objective problems. Decreasing the total network loss is often the main reason for using capacitors in distribution networks. Capacitor placement approach involves the identification of location for capacitor placement and the size of the capacitor to be installed at the identified location. An optimization algorithm decides the location of the nodes where the capacitors should be placed. As we know, the capacitors are categorized in two main types of fixed and switchable capacitors. Selecting an appropriate type of capacitor is related to the topology of network, load value and economic situation. They are also different from coding point of view. In this section, the model of coding is presented at first, and then, the approach of applying is described based on optimization algorithm. The capacitors are often used for peak loads but they may be present in the network in off-peak due to the switching issues. The network voltage may be increased in off-peak with the presence of capacitors. Therefore, it is very important to consider both peak and off-peak in the capacitor sizing and placement problem. The proposed model is applied on IEEE 10 and 33-bus standard test cases in order to demonstrate the efficiency of the proposed model.