Reduction of Transient Voltage Instability of High Voltage Transmission Network Using Unified Power Flow Controller (UPFC)

Abstract

Ideally, we would expect a Kampala Metropolitan High Voltage transmission network to be stable even if there is a transient voltage disturbance. However, due to lag in the network development, the existing high voltage transmission network operates at the margin of its capacity and experiences many power system losses due to transient voltage instability on the transmission line. According to UETCL, the transmission network will lack capacity in medium-term (10-15) years due to the load profile growth rate. [1] [2] This project's general objective is to model and evaluate the impact of the Unified Power Flow Controller in the reduction of transient voltage instability of the Kampala Metropolitan High Voltage Ring Network. This objective was achieved by collecting the electrical parameter from UETCL, modelling the Kampala Metropolitan High Voltage Ring network, modelling UPFC, and performing load flow and transient analysis. The project found out that Kampala metropolitan High Voltage Ring network operates at the margin of its capacity that is voltage level of average 0.95pu and unstable during a transient. With UPFC installed, the voltage level is regulated towards 1pu, the network response faster and dumps transient, and there is a reduction in line loadability. The project concluded that UPFC provides an advanced and economically viable solution to the transient disturbance in Kampala metropolitan High voltage ring network and recommends UPFC to solve the transient voltage disturbance, line congestion, and voltage compensation