Research On Delamination And Partition-Area Operation And Its Stability Of Hebei Southern Power Grid

With the development of power grid and the resultant upgrading voltage levels, operation mode of electromagnetic loop network was formed in order to get the most power rationally and satisfy the customer's demand before the higher voltage networks meet the request of supply reliability.The operation of electromagnetic loop network results in many disadvantage factors. On the one hand, a large amount of power flow pour into the lower voltage grid when the higher voltage grid is out of service, it can easily cause overload, malfunction of the protection and even destroy the system stability; on the other hand, this mode also leads to the difficulty to control power flow, increment of short circuit current, complexity of protection setting, etc. Hence, the research of break out electromagnetic loop network and carry out delamination and partition-area operation is one of the research hotspot issues.Under the existing network structure of Hebei Southern Power Grid, Because of electromagnetic loop network, most of the short-circuit current close to the operational limit, part of the 500kV substation short circuit current has been exceeded. With the strengthening of 500kV channels,the 220kV connect lines become less important,the time of decoupling the electromagnetic loop network has come.According to the current situation of Hebei Southern Power Grid, this paper researches delamination and partition-area scheme based on the basic operation in 2012, establishs indices such as flow distribution, short-circuit current, power loss, Line and transformer load to calculation the program.This paper uses direct method, time domain simulation method and modal analysis method to calculate the transient stability, small signal stability and the static voltage stability of the scheme, and obtained results.On the basis of considering different schemes and various factors, this paper puts forword a new comprehensive evaluation method of decupling electromagnetic loop network based on priority weights process to select the best scheme from all decoupling schemes. The scheme is consistent with the actual situation of Hebei Southern Power Grid and meet the requirements of power grid.