Network congestion assessment for short-term transmission planning under deregulated environment

Over the past decade, deregulation has been introduced in the power industry and has been influencing transmission planning immensely. In a monopolistic regime, transmission planning was based only on the reliability criteria. In fully competitive electricity markets, the traditional planning concept and paradigm must be replaced with a new set of criteria. Transmission planning should be driven by a combination of traditional transmission reliability criteria and new market-driven opportunities. This paper proposes a new methodology to promote fair competition for short-term transmission planning by using an assessment of transmission line congestion cost index. The new method introduced here is to minimize distance between market equilibrium point and operation point by redispatching power based on historical bidding data. Furthermore, this paper illustrates determination of optimal location and capacity of transmission line from the average total congestion cost index (ATCCI) under transmission line constraints. A sample system with hypothetical economic and load data has been tested to verify feasibility of the proposed method.