A Framework for Transmission Planning in a Competitive Electricity Market

In this paper, a framework for optimal transmission system expansion planning in a competitive electricity market environment has been proposed. Open access transmission has created a deregulated power market and brought new challenges to system planning. The goal of transmission planning is to determine an optimal planning strategy for the transmission company. From the planner's view, planning is the process for balancing the multiple conflicting objectives with many constraints. The primary objective of transmission planning is to ensure the reliable supply to the demand as economically as possible. The new approach in this paper is formed to minimize the expected energy not supplied (EENS), investment cost and maximize the benefit-cost ratio lambda subject to the power flow and security constraints. The computer program for reliability evaluation of bulk power systems CRUSE is used to perform reliability evaluation of the transmission system with predetermined outages. An advanced genetic algorithms (GAs) is utilized to solve the multi-objective optimisation problem. The advantages of the new approach include 1) it achieves the possible highest reliability with less cost; 2) it maximizes the cost efficiency, which increases the competitive advantage of a transmission company; and 3) the resulting plans contain the planner's preference which is easy to adjust. The planning approach has been illustrated on the Roy Billinton Test System (RBTS)