Loss allcocation and congestion management in bilateral markets

Abstract

Many electric supply industries around the world are on the pressure of changing from vertically integrated to more competitive markets, of which some of them have already been operating under competitive environment for a number periods of time. Among those electricity markets, various trading arrangements have been examined and improved for several years. In this dissertation, the concept of managing bilateral transactions under feasible and infeasible modes is studied. According to this management some transmission-related services, i.e. transmission loss and congestion cost allocation methodology are proposed based on contributory degree of each transaction. In addition, a methodology to evaluate transmission loading margin is proposed. This margin has a close relationship with voltage instability phenomenon and can be used for transmission planning and on-line voltage security assessment purposes. A slack-bus independent loss allocation method, based on a marginal loss concept of a specified source and sink under bilateral transaction, has also been proposed. However, a key contribution of this dissertation is on congestion management methodology under a bilateral market. The proposed method can be classified into two procedures, i.e. congestion relief and congestion cost allocation procedures. For a congestion relief procedure, it employs an objective function of minimizing congestion relief cost. For the congestion cost allocation methodology, the product of contracted power from each transaction and its Power Transfer Distribution Factor (PTDF) of the congested line is proposed as an index to allocate the congestion cost.