The Research On Security Stability Of Receiving Power Network After UHV-In Hunan

Security and stability are the most important issues in electrical power system. As the project of UHV is completed,it must cause a great impact on security and stability in the existing power system. So it is very important to study this question. About 2012, 1000kV UHV AC power grid into the Hunan, in order to ensure safe and stable operation of power grids, 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 has well 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 four typical load levels, including static power flow security analysis, transient stability analysis and voltage level analysis, after the UHV-in. 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-1 check. According to the characteristic of that most of power plants are in the northwest of Hunan,N-1 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. Calculated the change of Hunan 500kV central points short-circuit current of Power Grid before and after 2012 the main project UHV using PSASP. Calculating UHV three-phase short hitches occur in four typical load levels,in summer send to south 2600MW through UHV and in winter send to south 2600MW through UHV. Calculating 500kV and 220kV three-phase short hitches occur in typical load levels, in summer three ways in Southwest Hunan, eastern Hunan minimal boot mode. Calculating stable delivery of Leiyang, Lingjintan and more than 20power plant, had given the reasonable measures to deal with failure in accordance with the results; Calculation of the summer with small means of transmission line tower's stability; Calculated by the client system, the largest unit capacity of the stability of the trip in two kinds of load level. Calculated the voltage level of Hunan grid,after the UHV-in, analysis the transient voltage stability of the UHV and Hunan power grid on the effects to the transient voltage stability of the UHV.Based on the actual Hunan power network after UHV-in, the existence of specific circumstances in security and stability, 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.