Investigation and Voltage Profile Improvement using D-STATCOM FACTS Devices (A Case Study Welenchiti City Distribution System)

Abstract

Ethiopia's electricity demand, like the rest of the world, is growing at an alarming rate, with electricity demand out stripping supply. One of the challenges is a reliable power supply with affordable energy prices and reduced CO2 emissions. Distribution feeders play a crucial role in transferring power from distribution substations to transformers near the customers' locations. However, certain issues such as low power factor, excessive loads, and long travel distances hinder their effectiveness in delivering electricity to connected customers. Voltage variations and under voltage are common problem for the Welenchiti city water pumping station, industries, commerce and residential end use. It is necessary to create techniques to improve the performance of distribution feeder voltage profile. To address these issues and improve the voltage profile of distribution feeders, integrating a D-STATCOM (Distributed Static Synchronous Compensator) into the R_7.2 Welenchiti distribution feeder can be a viable solution. Adama distribution substation, part of the Oromiya electric utility, has multiple outgoing feeders supplying power to Adama, Welenchiti, and koka towns. Among these feeders, the R_7.2 feeder has been chosen as the test system due to its long route and heavy loads. This work compares voltage profile and line losses (reactive power, active power) without any compensating device and then with compensating device (D-STATCOM). Forward/backward sweep load flow analysis and the PSO optimization technique were used to determine the best location and size of the compensation devices. Based on PSO the optimal size of a D-STATCOM is 999.8232 kVAr. Following this, simulation results shows that the active power loss is reduced from 2511.1KW to 229.0662KW and the reactive power loss is reduced from 1374.5KVar to 126.5238KVar. The reduction of the active and reactive power losses is 90.88% and 90.79% respectively and the minimum voltage becomes 0.96266p.u which confirms lower IEEE voltage limit.