Fault Location for Distribution Networks Based on Node Voltage Equation

Abstract

This paper proposed a method to estimate shortcircuit fault location in electrical distribution networks using voltage sags data and current measured at the local substation. With the knowledge of bus impedance matrix, the bus voltage during the fault can be obtained for any fault in the network. Based on the non-liner profile characteristic of voltage sag measured at the bus, the paper proposed a new method. Firstly, voltage quantity for each section is expressed as a function of fault location and resistance base on the bus impedance matrix. The possible fault is estimated by incorporating the real and imaginary part of voltage sags into the node-voltage equation. Then, the method applies rank reasoning analysis to prioritize the possible fault locations due to the same electrical distance. In this method, the uncertainty of fault resistance is also considered. Through simulating for an 11kv typical test distribution network, the method's validity and accuracy are proved.

T-Shaped Transmission Line Fault Location Based on Phase-Angle Jump燙hecking

“…The second type of fault analysis and location methods can be divided into synchronous fault analysis method [5][6][7][8][9][10][11][12][13] and asynchronous fault analysis method [14][15][16][17][18][19][20][21][22][23][24] according to the synchronization and asynchrony of 3-terminal measurement data. The literature [11][12][13] achieved the purpose of fault location by constructing a phase-comparison function based on the synchronous measurement of phasors at the 3-terminal of the T-shaped transmission line, but the existing phase comparison function method basically realizes the fault point location by segmented and point-by-point search and the accuracy of fault location is mainly determined by the search step-size.…”

“…The total length of the line mn is L, where point f is the fault point, point k is the reference point, and point k is located to the right of point f. According to Fig. 1, the distribution of fundamental positive sequence voltage and current phasors at points f and k away from the point m can be obtained [8,9].…”

“…( 5) and ( 6), and considering the asynchronous phase angle difference of PMU systems at point m and point n is δ, the function f (l mk ) can be constructed, as shown in Eq. (9).…”

Voltage sag source location based on power polarity and twin characteristics matching

“…References [16,17] use the traditional voltage sag source location method to extract five types of sag source features as the input of vector machine SVM and optimize the solution by particle swarm and other algorithms, but it is greatly affected by measurement error. References [18][19][20] use historical operation data to form a database and use adaptive particle swarm and other algorithms to match the sag information with the database to locate the fault, and the location error is greatly constrained by the solution accuracy of intelligent algorithms. Reference [21] establishes a least-squares state estimation model based on the measurement of each phase voltage quantity at the monitoring points to solve the fault distance and transition resistance, but the fault type needs to be known and the location error is large.…”