A hybrid probabilistic criterion for market-based transmission expansion planning

Market-based transmission expansion planning gives information to investors on where is the most cost efficient place to invest and brings benefits to those who invest in this grid. However, both market issue and power system adequacy problems are system planers´ concern. In this paper, a hybrid probabilistic criterion of expected economical loss (EEL) is proposed as an index to evaluate the systems´ overall expected economical losses during system operation in a competitive market. It stands on both investors´ and planner´s point of view and will further improves the traditional reliability cost. By applying EEL, it is possible for system planners to obtain a clear idea regarding the transmission network´s bottleneck and the amount of losses arises from this weak point. Sequentially, it enables planners to assess the worth of providing reliable services. Also, the EEL will contain valuable information for moneymen to undertake their investment. This index could truly reflect the random behaviors of power systems and uncertainties from electricity market. The performance of the EEL index is enhanced by applying normalized coefficient of probability (NCP), so it can be utilized in large real power systems. A numerical example is carried out on IEEE reliability test system (RTS), which shows how the EEL can predict the current system bottleneck under future operational conditions and how to use EEL as one of planning objectives to determine future optimal plans. A well-known simulation method, Monte Carlo simulation, is employed to achieve the probabilistic characteristic of electricity market and genetic algorithms (GAs) is used as a multi-objective optimization tool