Optimum reactive power compensation & voltage control using static var compensator for grid substations

Abstract

As the volume of power transmitted in transmission lines increases, maintaining high quality and reliable power supply is required. Modern power systems sometimes operate with heavily loaded lines resulting in power system to work under condition of higher power loss and higher voltage deviation. Sometimes, it may lead to voltage instability or system collapse. The emergence of power electronic based FACTS technology such as Static Var Compensator (SVC) has been of great help in improving the operation of power systems as it reduces the power system instability problem, power losses and voltage deviation. Placing FACTS devices at proper locations can serve the purpose of improving voltage levels and reducing losses in the system. Due to huge investments associated with SVC, a proper analysis and planning is required before the installation. The objective of the study is to use optimization technique for minimization of power loss and voltage deviation along with installation cost calculation for the selection of SVCs for grid substations. Whole Sri Lankan power system has been modeled using the PSS/E (Power System Simulator for Engineers) software. The voltage deviation of all the buses in the network and the total active power loss in all the transmission lines are analyzed with SVCs and without SVCs using PSS®E software. Further, single line outages are considered as contingencies for optimal placement of SVC. Finally, optimum combinations of SVCs are selected to minimize the system voltage deviations and active power loss of transmission lines.