Reconfiguration and Enhancement of Multi Feeder Radial Distribution System of Pulchowk Distribution Network Lalitpur, Nepal

Abstract

In the current power system study, the topic related to distribution system; especially on distribution network re-configuration is a very important one. This concept helps to re-structure the distribution as well as transmission line in the existing power system. In this study, this concept is applied as a policy-making tool, that addressed the issues related to the poor voltage profile occurred in the existing distribution system. The voltage margin is improved through the configuration of tie-switches and sectionalizing switches, in between the existing radial feeders. A Genetic algorithm-based model has been developed to enhance the bus’s voltage by optimal operation and allocation of the sectionalizing switches and tie switches. The proposed algorithm evaluates the base condition of loss and bus voltage, and then generate populations of switching points from the available feeders for the tie-switches and sectionalizing switches on the existing base configuration. It works with the main objective to minimize the active power loss and voltage drop, under a constraint of existing feeder limit and possible location of the switches’ limit. An IEEE-33 bus system has been tested at first and then compared with the real case study of Pulchowk distribution network area for the model and result verification. In the Pulchowk distribution network of 9 different radial feeders having 142 bus systems in total, it was observed that, most of the lines are facing the problems relating voltage drop and power loss. In this study, an optimal configuration has been identified from all of the possible configurations, by conducting the forward/ backward sweep algorithm based load flow analysis study. From the different cases of the possible networks, the best case is considered to be optimal with respect to the percentage of reduction of power loss and voltage drop from base case. From this study, the power losses and the lowest voltage profile for the Pulchowk feeder are calculated to be 1073.08 kW and 0.7694 pu at bus number 98. After the re-configuration, the power loss and voltage drop are found to be reduced by 44.29%and 3.85% from the base case scenario. Hence, it is concluded that, the optimal configurations of the distribution system can be identified by using some computational techniques that helps to reduce the system loss and voltage drop significantly.