Optimal Power Flows: Uses, Methods and Developments

Abstract

Optimal power flows are basic tools for the secure and economic operation of Power Systems, but are presently applied in a few energy control centers only. The first part of this paper is dedicated to an analysis of possible statements and uses of this technique. New results providing consistency with daily power scheduling in such systems as hydro power systems are pointed out. In the second part, the main methods now available are reviewed, including parametric algorithms, with a critical analysis of the relevant performances for on-line applications. In the third part, present developments performed at Electricite de France are described. They aim at suppressing shortcomings existing in present methods. Some very new results have been obtained. These developments build up a consistent and secure operation optimization system, from daily power scheduling up to automatic control, with Optimal Power Flows as the basic tool. In particular, a new load flow technique with “implicit active reactive coupling”, improvements in speed of the optimal power flow and the inclusion of the latter into a closed loop secure economic dispatch are presented.