Study On Short Circuit Current Of Jiangxi Power Grid And Control Measures

With the continual strengthening of Jiangxi grid structure and the increasing of generating units,the short-circuit current level in the network is getting higher and higher,and some substation short-circuit current of the substation has exceeded the breaking capacity of the circuit breaker.The short-circuit current condition of Jiangxi power grid to be analyzed and studied in advance measures is now an urgent demand for Jiangxi power grid.In addition,the "three five" during the UHV will access Jiangxi power grid to further enhance the Jiangxi current short circuit current level.So how to effectively limit the power grid short-circuit current level has become a major constraint to the development of power grid.Based on the structure of Jiangxi main power grid and the planning of Jiangxi power grid in the next two years,this paper analysed the short-circuit current level of Jiangxi power grid in the next two years of Jiangxi Power Grid and the UHV AC / DC access.Based on the analysis of the basic principle of short-circuit current and the calculation method of DC component of short-circuit current,the DC component attenuation of 90% of the switching off current of Jiangxi power grid is made on the basis of the most widely used short-circuit current limiting measures,and time constant calculation of the Jiangxi power grid short circuit current DC component on the breaking capacity of the circuit breaker.The reason and method of short circuit current increase in Jiangxi power grid are analyzed,and the measures and methods to deal with the short circuit current are put forward.The calculation results show that the short circuit current can be shortened by breaking the relevant line,Busbar segmented operation and main transformer Control is within the safe range of operation.