Simultaneous optimization of transformer tap changer and network capacitors to improve the distribution system’s static security considering distributed generation sources

Voltage control and reactive power play an important role in the operation of the distribution network. Accordingly, conventional methods such as the installation of a capacitor in an optimum location with a proper capacity and optimal transformer tap setting which has an impressive effect on voltage control and reactive power are used. But the study on the simultaneous use of these two methods is limited and it seems necessary to be conducted. These days the presence of Distributed Generation (DG) resources has grown in distribution networks. The presence of distributed generation resources has a great influence on the voltage profile due to the radial structure of the distribution network and the low X/R ratio. Therefore, it is necessary to consider the optimal coordination of the use of switchable capacitors and the setting of transformer taps in the presence of distributed generation resources to improve the voltage profile and reduce losses. This paper examines the simultaneous use of capacitors and transformer taps in distribution networks to reduce the voltage deviation and distribution losses in the presence of distributed generation resources. In order to explain the objectives, six different operation scenarios have been defined and studied. The above study is implemented based on the IEEE, 13 and 34 bus standard networks and the results are presented. The presented results clearly indicate the necessity of coordinating the use of these tools in distribution networks