Voltage Profile Enhancement in a Transmission Network Using Static VAr Compensator

Abstract

Voltage instability has been a major issue in the Southern Nigeria Transmission network. It is essentially caused by reactive power inbalance in the system which characterizes the frequent collapses occurring in the grid network of Nigeria, thereby making Nigeria to have about the highest loses in the world. Several methods by which voltage regulation can be achieved in the transmission network have been explored such as synchronous generator, reconfiguration of system structure, changing the voltage by transformer tap to adjust the power flow in the grid, series compensation capacitor, switching in or out the shunt reactor and generator excitation regulation. However, Flexible Alternating Current Transmission System is found out to effectively control reactive power.  Static VAr compensator (SVC) which is a FACTS device is used in this study to stabilize voltage systems in the Nigerian transmission Network.  The southern Nigeria Transmission network is designed in Electrical Transient Analyzer Programme (ETAP) and Load flow analysis is applied to determine the level of voltage at the buses. The modeled network is first simulated without a SVC and the result shows the need for the enhancement of the Voltage Profile. Thus, the need to incorporate Static VAr Compensator installed correctly in the network using sensitivity factor and then repeat the load flow to check for voltage improvement.  The result after the compensation technique shows clearly that the voltage has improved. It is now obvious that the application of Static VAr Compensator in a transmission network improves the Voltage Profile of the Network.