Voltage Profile Improvement Analysis of 11 kV Feeders Using Capacitor Banks

Abstract

This paper discusses the voltage drop problem in a medium voltage (MV) distribution network, specifically focused on a radial distribution feeder. This feeder is a highly loaded 11 kV voltage level, where the feeder source is regulated 11 kV busbar. Currently, many distribution substations are getting poor voltages violating the minimum permissible limit with frequent complaints from the customers. Load shifting and power transformers tap changers at the main substation as well as at the distribution transformers are unable to achieve the optimum voltage value. Also, the voltage drop control measures in distribution feeders are discussed. To analyze voltage improvement, a case study feeder has been modeled and backward/forward power flow technique simulation is utilized to calculate the voltage drop at the LV side of the distribution transformers with and without capacitors. Currently, capacitors are only installed for power factor (PF) correction in our MV distribution radial OHL feeders, while voltage enhancement is considered as an additional benefit but not the main driver of capacitors' installation. Accordingly, this paper investigates the utilization of capacitors for voltage profile enhancement as main purpose. The analysis of capacitors' impact elaborates the reduction of both load losses and voltage drop and the expected savings. This paper could be considered a baseline for similar network behavior in the middle east region.