Research On Security And Economy In The Electricity Market

Electricity market is a typical inter-disciplinary research domain which conjugates economics and engineering together. The security and reliability of power system must be assured while optimal allocation of electrical energy resources and maximization of social benefit are achieved in the competitive electricity market. Issues related to cooperative game, transmission transfer capability and double auction market structure are studied in the thesis from the economics and security points of view. The main results are as follows:Taking the optimal power flow and locational marginal price as analytical tools and based on the nucleolus in the cooperative game theory, a method to allocate the cost and profit of the interconnected operation of multi-area power system is presented. Comparing with the allocation result by Shapley value, those obtained by the presented method show that the rational allocation of cost and profit of interconnected operation among the participants of electricity market is implemented, and both individual rationality and group rationality are satisfied, so the stability of the coalition structure is ensured. All of these are propitious for the formation of unified electricity market.Transmission transfer capability has significant effect on the reliability of interconnected bulk power systems. In electricity market, the transfer capability between areas is a signal inducing market behaviour. In this thesis, power systems voltage stability influenced by load increasing and transmission line contingency are taken into accounted. A model for available transfer capability calculations accord with trade-off mechanism is set up. Contingency ranking is performed through sensitivity indices between branch flows and the system loading margin. Optimal power flow with the N-1 voltage security constraints is applied to solve the available transfer capability problem. The calculation results show that the transfer capability between areas can be evaluated correctly by the proposed method.Electrical Energy resource can be allocated efficiently and generation market power can be decreased in the double auction market structure. The mathematical model of double auction is analyzed explicitly in the thesis. A method combined continuation power flow with optimal power flow to detect vulnerable spots of the transmission network is proposed, with considering market participants bid at a certain price level. The deal plan which can assure the reliable operation of power systems meanwhile achieving the maximization of social benefit is established by voltage security constrained optimal power flow when the detected vulnerable spots in the transmission network are involved.