Online VAR support estimation for voltage stability enhancement

The existing resources in present day power systems are inadequate to meet the ever-growing load demand and as a result the grids are operated closer to the voltage stability boundaries. The system is therefore prone to voltage collapse even for a small increase in load demand. VAR support appears to be the only viable remedial measure. This paper develops a fuzzy based online tool to determine the minimum VAR support required for a projected load demand with a view to ensure voltage stability in a power system. The tool incarnates a methodology through which the operator can initiate steps to improve the voltage profile and bring the system far away from the point of voltage collapse. It includes the test results of three IEEE systems to exhibit the viability and effectiveness of the proposed method. (C) 2013 Elsevier Ltd. All rights reserved.