Particle Swarm Optimization Based Distribution Static Compensator Placement for Loss Minimization and Voltage Profile Improvement. (A case study of Sabbata-I Substation outgoing Feeder)

Abstract

The distribution system is the end part of the electrical power system that delivers electric power to the load demand. The majority of power quality issues including losses, weak voltage profiles, voltage instability takes place in the distribution system. The primary concern of any electric utility is to meet rising load demand with high quality. Installing capacitor banks, network reconfiguration, distribution generation, and upgrading distribution cables have all been attempted to solve such kind of power quality issues. In this thesis work, the optimal size and placement of the distribution static compensator in the radial distribution system was used to reduce losses, improve voltage profile and voltage stability. The forward/backward sweep algorithm was used to do the load flow analysis of the existing system, and to evaluate whether the system is run efficiently or not. The voltage stability index has been used to identify the candidate buses for optimal placement of distributed static compensator, while the particle swarm optimization algorithm has been employed to determine the appropriate size and placement of the device. The study has been carried out on the Sabbata-one substation on the feeder which has 89 buses. The objective function of the thesis work was to reduce both active and reactive power, improve voltage profile and voltage stability by providing sufficient reactive power to the feeder. As a result, the optimal size of distributed static compensator that has been determined by particle swarm optimization was 1103.42kVAr, whereas bus 76 is the appropriate location of the device. The result of the system has been showing that the total active power loss decrease from 403.0803kW to 334.2578kW, while reactive power loss decrease from 356.1287KVAr to 296.778KVAr. The percentage reduction in real and reactive power loss became 21%, and 20% respectively. The entire voltage profile of the feeder has been enhanced within the required standard level with the minimum bus voltage of 0.950001(p.u), and the voltage stability index has been improved with a minimum value of 0.8145(p.u). The total annual cost wastage due to power loss has been minimized after the integration of the distribution static compensator. As a result, the Ethiopian Electric Utility can save 55,872.5$ per annum with a payback period of about one year, and the percentage of cost reduction due to system loss was about 35.82%.