Research On Method And Technology Of Congestion Management Applying To Direct Power Purchasing Market

Power industry has natural monopoly as the production, transportation, distribution and utilization of power are synchronized. However, the continuous development of the electricity technology makes it possible for the establishment of power market in which every segment of power industry is relatively independent. In the 1990s, the market reform of power industry was gradually carried out in western countries which have formed several mature markets in certain countries or areas in nowadays. Power industry in China has conducted a lot of research work and pilot projects in order to establish an open power market. In 2015, the State Council issued the key tasks of the power market reform in the document, pointing out that access for direct-purchasing contracts should open gradually. The increase of power direct-purchasing contracts may cause certain threat to the security and stability of power grid. The transmission congestion caused by the heat capacity of transmission lines is one of the most significant factors that affect the security of power system. It is an urgent task to come up a management method to eliminate the transmission congestion. In this paper, researches are conducted with the applicative technology and method of congestion management for the situation of the coexistence of direct-purchasing and Sangong dispatch in China.There has been mature technology and abundant experience about congestion management in other power markets. However, each method for congestion management should be combined with the corresponding market environment and market mechanism. In this paper, the market mechanism and the corresponding congestion management of several power markets was studied, and the advantages and disadvantages and applicability of each congestion management method was analyzed. The current dispatching method in China was also studied, and an applicable method to eliminate transmission congestion was given considering the situation of the coexistence of power direct-purchasing and Sangong dispatch.Besides the elimination of transmission congestion, another task of congestion management is to fairly allocate the additional cost in congestion scheduling. Combined with the dispatch method in Chapter 3, a cost allocation method based on the transfer factor of the net node power injection to the transmission power is presented in Chapter 4. And the fairness of this method is analyzed.The congestion management method is analyzed with a 6-node power system in Chapter 5. The settlement of the system is compared with other congestion management methods which verify the effectiveness and applicability of the method in this paper.