Coordinated static and dynamic reactive power planning against power system voltage stability related problems

Power System, over the many years, has undergone dramatic revolution both in technological as well as structural aspects. With the ongoing growth of the electric utility industry, including deregulation in many countries; numerous changes are continuously being introduced to a once predictable system. In an attempt to maximally use the transmission system capacities for economic transfers, transmission systems are being pushed closer to their stability and thermal limits, with voltage instability becoming a major limiting factor. Insufficient reactive power support affects the reliable operation of electric power systems leading to voltage collapses as observed by the recent 2003 blackout. Among the many available solution options, installation of reactive power control devices such as MSCs, FACTS devices etc seem more viable. This is a typical long term planning problem that needs to consider both steady state as well dynamic condition of the power system after severe contingencies and use better informative indices for the planning process.;A mixed integer programming based algorithm is made use of in this work to develop a comprehensive tool to perform a coordinated planning of static and dynamic reactive power control devices while satisfying the performance requirements of voltage stability margin and transient voltage dip. The systematic planning procedure is illustrated on a large scale case study. The effectiveness of the planning algorithm is demonstrated using two separate planning problems, one where steady state planning is done exclusively against static voltage stability problems, and the other where a coordinated steady state and dynamic Var planning problem is solved.;The results of this work show the effectiveness of the developed planning tool to find a low cost optimal reactive power allocation solution to enable higher real power transfers and improve voltage stability. We envision the method developed will be a research grade tool for planning reactive control devices against voltage instability and will provide system planners a proper guide to find viable and economical planning solutions