Optimization for the Online Assessment of Real-time Switch Resistance in Switching Stations

Abstract

Abstract-It's important to access the status change of switchgear in switching station for condition maintenance. With regard to the online assessment for the resistance of switches in the switching station with 3/2 connection mode, linear equations can be established on the basis of real-time current measurements. The accuracy of the solution for these linear equations will make a great difference to the whole assessment because of errors in real measurements. To make the calculation for the value of the resistance more accurate, some equations are selected in this paper by comparing matrix condition number. The size of this number reflects the degree of the linear correlation of the equations: the smaller the matrix condition number is, the less influence the variation of coefficient matrix will have on the solution of the equations. Therefore, the condition numbers of all the combinations of coefficient matrixes corresponding to real-time operating conditions should be calculated and the combination with minimum condition number should be selected. In this paper, simulation studies on the current data obtained from 500kV switchgear are carried out to verify the effectiveness of the proposed method.