Evaluation of Requirements for Volt/Var Control Implementation in Transmission Grid

Abstract

The objective of the Volt Var Control (VVC) function is maintaining system voltage within predefined limits and minimizing system active power losses by controlling reactive power flow. The main focus of this paper is to review and evaluate the technical requirements to implement a centralized VVC function within an existing SCADA/EMS system in a transmission system operator. The paper focuses on the implementation of a centralized VVC function. The function is based on an optimal power flow algorithm with input from the state estimation function and output to the SCADA control functions. The challenges of the implementation are related to the limitations of the existing network model and mathematical modelling of network elements, input data, measurement quality and state estimation output reliability. The paper presents some of modification in the network model and EMS (Energy Management System) functions that will improve quality of VVC results.