The Research On Security And Stability Level Of Hunan Power Network In Power Market Environment

Security and stability are the most important issues in electrical power system. Recently there is a lake of electrical power in many places of our country ,including Hunan province. Constructing power plants and strengthening power network are the mostly contents in electrical power system now. So it is very important to study the security and stability of power network. In this paper, the security and stability level of Hunan power network is analyzed in detail, which have good on improving the structure of hunan power network.In this paper, by using PSASP program, the security and stability of Hunan power network are studied according to three typical load levels of 6500MW,5500MW and 2000MW, including static power flow security analysis, transient stability analysis and the research on the stability of power network in power market environment. Firstly, the power flow distributing of hunan power network is calculated and analyzed as a whole and the static state security level is studied by using N-l check. According to the characteristic of that most of power plants are in the northwest of Hunan, N-l check is applied respectively when the power plants in the northwest of Hunan generate electricity differently. Transient power angel stability problems consist in the northwest Hunan power network primarily. So when three-phase short hitches occur in the outlet transmission lines of the northwest power plants, 500kV Gangshi transformer or 500kV Fuxing transformer respectively, the transient stability level of Hunan power network is analyzed particularly in this paper , which prove that the stablity level of 500kV Gangshi transformer is lower than that of 500kV Fuxing transformer and all of the northwest Hunan power plants cannot generate electricity entirely because of the stability problem of Hunan power network. It is also proved that all of the northwest Hunan power plants can pass the transient stability check when three-phase short hitches occur in their outlet transmission lines except Lingjintan power plant, because the running inertia of Lingjintan power plant is very lower . In Hunan power system most of electric energies are transmitted in the distance from the west to the east, which result in the voltage problem in the middle of Hunan power system. So the transient voltage stability is calculated and analyzed distincly by adjusting the outputs of Huayue power plant and Xiangtan power plant. Based on the electromagnetism loop network of 500\220kV, the compared analysis is discussed when the electromagnetism loop network is cut or connected, which proves that thestablity level of connecting operation mode is higher than that of cutting operation mode in present power network structure. By using N-2 check, the security and stability of Hunan power system are studied more.Many new problems will produce in electrical power system during power market actualizing. Lois of stability problems in power market environment are studied in this paper. Discussion is carried out about stability check, congestion management, equipment maintenance, ancillary services etc.. Especially the typical congestion of Hunan power network is studied and a method of market split is indroduced to solve the congestion.4Based on the actual Hunan power network, the weakness and the existing problems in Hunan power system are pointed out, and some good measures are carried out to improve Hunan power network.