The complexity of voltage and reactive power dispatch in control centers: From analysis to on-line decision making

This paper describes the need for on-line decision making in support of reliable, clean and efficient operation of future electric energy systems. This operation will be critically dependent on the systematic dispatch of available resources ranging across real power generation and voltage controllable G&T&D equipment. The emphasis in this paper is on the role of on-line voltage dispatch. An extended AC Optimal Power Flow (AC XOPF) is introduced for computing decisions on-line. It is shown how this software enables optimization of technical and economic decisions in quantifiable ways. Focus then turns to experience with large system studies. It is observed that on-line dispatch of a variety of controllable equipment over the broad range of system conditions is becoming critical during both normal and contingency conditions.