Research On Short Circuit Current Limiting Scheme Of Tangshan Power Grid Based On Hierarchical Partition

With the scale of Tangshan electric power grid expanding,Tangshan region economic development and the demand for electricity and installed capacity is increasing.Power grid of 500 kV and 220 kV gradually improving.Switchgear interrupting capacity of some factories and stations has obviously cannot meet the system requirements,which is also an important factor that restricts the power system development.There is an urgent need to take measures to limit the short circuit current levels with reasonable limits.In order to solve the exceeded problem of short-circuit current in Tangshan electric power grid in 2016,it formulates short-circuit current limit scheme for the region.First it researches the current-limiting mechanism of the short-circuit current limitation measures and its characteristics,the advantages and disadvantages of each measure are analyzed.The reasonable solution of short circuit current limiting methods is to transform existing power grid structure and change devices.In this paper,the auxiliary measures include furnishing high impedance reactor,series reactor,high-voltage direct current transmission technology and add a small reactance to transformer neutral point.This thesis studies on the fundamental theory of delamination and partition-area fundamental theory,analyzes the benefit and weakness of the opening loop network,discusses the key technology,concludes the fundamental principle and the general process,etc.This part is the main basis for the implementation of Tangshan grid partition scheme and the major determinant of success of current limiting measures.Power system stability,short circuit capacity of the power system,the power balance of partition and economy are main factors of delamination and partition-area.Finally,the paper studied the Tangshan grid specific hierarchical partitioning scheme.Based on the study of Tangshan electric power grid structure as well as the short-circuit current limiting characteristics,it formulates the Tangshan electric power grid short-circuit current limit scheme in 2016,limit short-circuit current level in the permitted range.The proposed scheme provides advice and reference for in Tangshan electric power grid of short-circuit current limiting has practical value.