Rule-based system for determining unit locations of a developed generation expansion plan for transmission planning

Abstract

A rule-based expert system (ES) for determining the realistic location alternatives of a developed generation expansion plan and the initial transmission expansion scheme of a typical fast development power system is described. In the proposed ES, the key variables that affect generating unit location are first identified. So, a multitude of technical, economical, environmental and feasible siting constraints are established by system planning engineers for different areas over the planning horizon. A set of decision rules relating these key variables are then established and stored in the knowledge base. With the knowledge base at hand, a list of realistic location alternatives of the new generating units is defined. However, to determine the optimal and sub-optimal location from this list, the system operating cost and the capacity of the tielines among different areas, as well as its investment, should be taken into consideration. Therefore, the electrical network is simplified as a generalised network programming (GNP) formulation, to optimise the location for new generation and its initial transmission expansion scheme simultaneously for each alternative. The optimum and sub-optimum alternatives that will minimise the overall system cost function and satisfy the demand requirements under normal operation and the contingency condition are obtained. The outcome of the proposed method will provide the first step on which the subsequent steps of transmission planning are based. The proposed method would be appropriate for an electric utility in which there is a central planning organisation. A practical application is given to demonstrate the usefulness of the developed prototype system.