System Optimization - A Central Function of Operation Planning

Abstract Operation planning is a complex field of functions the computerized solution of which requires the division into decoupled subtasks in most cases. As an introduction an explanation of the working principle of decoupling will be given. In the following the objectives of planning will be described concerning their dependence on system states and the constraints will be characterized. Starting from the present practice the extensions of two specific subtasks will be discussed. For this purpose the first part of this paper deals with the computerized operation planning of the generating system for time periods of one year or longer. Accurate solutions of such problems require calculating models which are able to take into account stochastic influences, e. g. forced outages of generating units. The second part of the paper deals with the computational coupling of the generating system and high voltage network for short-term optimization. Recently developed models for this purpose are able to solve the problem of optimal power flow for an instantaneous as well as for an extended range of time. Capabilities as well as appropriate limitations of such improved calculating models are illustrated for both topics - the operation planning of the generating system with stochastic influences and the computational coupling of the generating system and network.