An approach to the safety and cost control of electrical grid in power market

Realizing the safe and economic operation of electric power system has great meaning to the development of country´s economy, so the electric power technicians and scholars always pay much attention to the electric power market, security economic dispatch problem. Along with the development of power market, the safety and cost control faces many new problems: first, because of the asymmetry of the structure and distribution of electrical sources, to realize the configuration of electric power resource of whole country, the exchange of electric power between areas which most of he form is bilateral transaction is getting more and more frequent, so the cost control must adapt itself to this demand; second, for maximum profit, there will bring antinomy between the security of transmission network and the free transmission of electric power, that is in given transmission network, if the free transmission of electric power is too emphasized, the electric system will breakdown; whereas if the security of transmission network is too emphasized, the market will be lost. In power market environment, system operator will reduce the security margin of transmission system for more profit by considering that the preconceived contingency may not really happen. Therefore, the safety and cost control postulate strictly, and that the transmission limits of lines in area and ties between areas must consider at one time in the model of the safety and cost control between areas. In this paper, we introduce the definition of the safety and cost control of electrical grid under power market environment and the OPF problem (which can consider security and economy at the same time). The main content is as follows. Firstly, analyzing the security economic dispatch problem which objective is to minimize the fee of purchasing electric power under bilateral trade model. Secondly, discussing how to realize the fixed bilateral contracts between areas to improve the profit of the system in he de- regulated power system. Thirdly, different from that most of the transactions between areas are fix bilateral transactions under the monopoly model, in power market model; we must fully consider the economy. In the precondition that other networks have been deregulated, we must constitute trade plan on principle of maximizing the profit.