Research On Short-circuit Current Limiting Methods For Jibei Electric Power Grid

With the scale of Jibei electric power grid expanding and power grid of500kV and220kVgradually improving, the electrical contact between the grids increasingly close, causes short circuitcurrent level increasing. Switchgear interrupting capacity of some factories and stations hasobviously can not meet the system requirements, which is also an important factor that restricts thepower system development. There is an urgent need to take measures to limit the short circuitcurrent levels with reasonable limits.In order to solve the exceeded problem of short-circuit current in Jibei electric power grid in2015, 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, exploresthe proper computational conditions of short-circuit current in Jibei electric power grid, so concludethat: the precise calculation model of short-circuit current which takes the line charging power andstatic load into account is a suitable calculation model in Jibei electric power grid; then according toJibei electric power grid structure and the short-circuit current level in2015, on the basis ofresesrching adaptability of short-circuit current limiting measures in Jibei electric power grid,formulates four sets of short-circuit current limit scheme, with reconstruction network being thefirst choice and change devices being the second choice; builts an evaluation model of short-circuitcurrent limiting scheme which considers the urgent need to limit short-circuit current, this modelscores short-circuit current limiting scheme from four aspects of limitingeffect, static stability, dynamic stability, and considers the different urgency of limit the current inscoring limiting effect; at last utilizes the proposed comprehensive evaluation model in4sets ofshort-circuit current limit scheme in Jibei electric power grid to pick up the most suitable one.Based on the study of Jibei electric power grid structure as well as the short-circuit currentlimiting characteristics， it formulates the Jibei electric power grid short-circuit current limitscheme in2015. The proposed scheme provides advice and reference for in Jibei electric powergrid of short-circuit current limiting, it has practical value.