A Novel Method for Fault Location of Transmission Lines by Wide-Area Voltage Measurements Considering Measurement Errors

Abstract

Smart transmission grids are intended to utilize various measurements for enhanced operation. In particular, synchronized phasor measurements have found many applications in this context. This paper presents a linear weighted least-squares (WLS) method for fault location estimation of transmission lines by synchronized voltage measurements. The measurements may be taken from the faulted line terminals or buses far from the faulted line. The circuit equations of the network are used to find the transfer function between the fault location and each voltage measurement. Next, two auxiliary variables are defined to transform the nonlinear fault location estimation problem into a linear WLS problem. A closed-form solution is then obtained for fault location. The use of multiple measurements provides the opportunity of identifying erroneous measurements by a statistical test. The linearity of the problem expedites both estimation and identification procedures. Moreover, the method requires neither to classify the fault type nor to estimate the fault resistance. Furthermore, transmission lines are modeled by distributed parameters so that the method can be applicable to long lines. Electromagnetic transient simulations for 9-bus and 22-bus test systems reveal accurate fault location estimation, regardless of fault type and resistance, as well as successful identification of measurement errors.

Locating Faults on Untransposed, Meshed Transmission Networks Using a Limited Number of Synchrophasor Measurements

“…Due to space limit, only the obtained results by [31] for faults on line 26-28 has been reported and discussed in this part. It should be noted that almost the same inexact results have been obtained using the method proposed in [32]. Table II summarizes the average and maximum estimation errors of more than 800 fault cases.…”

“…The more recent and effective fault location methods [31] and [32], use the available PMU data and give rise to almost the same accurate results. Furthermore, bad data detection can be readily deployed in these methods to achieve the highest possible accuracy.…”

Design and performance evaluation through synchro-phasor signals for transient fault analysis in transmission lines and distributions

“…Cross-correlation and the relative spectrum between the ideal signal and the induced single transient fault have also been calculated and shown in figure 17(a) and 17(b). The flux phase difference between different types of faults are tabulated as follows: 16.99 seconds after that from 17th second the characteristics of the signal starts vary that resembles that the fault is initiated at the 17th second from the transmission line while it is traveling to the load. The output is shown in figure 18.…”

Experimental studies on impedance based fault location for long transmission lines

“…In the first category, the global positioning system (GPS) is required. The measured values form the both ends are synchronized by GPS clock [7,8,11,12]. The other hand, in other categories, the GPS system is not needed [8,9].…”