Fault location

Wp - Windings of a power equipment or section of a power system to be protected Fault location t ... 

The relay stays inoperative for a fault occurring outside the protected zone even if it is within the CTs zone Fault location 2 ... 

Contacts with other pipelines or grounds can be localized to within a few hundred meters by pipe current measurements. Contacts with foreign pipelines or cables can also be found by measuring potential at the fittings of the other line while the protection current of the cathodically protected pipeline is switched on and off. While the potential of unconnected pipelines will assume more positive values when the protection current is switched on, the cathodic current may also enter any line in contact with the cathodically protected pipeline and thus shift its potential to more negative values. Should the contacting line not be located by this method, fault location can be attempted with direct or alternating current. 

Location of faults by the direct current method is based on the application of Ohm s Law. It is assumed that, because of the good pipe coating, virtually no current passes into the measured span and that the longitudinal resistance R is known. When the fault-locating current, I, is fed in and takes a direct path via the foreign line to the protected pipeline, the fault distance is determined from the voltage drop AU over the measured span ... 

With the advent of digital relays, the situation changed dramatically. Not only could the relays record the fault current and voltage and calculate the fault location, they could also report this information to a central location for analysis. Some digital devices are used exclusively as fault recorders. 

Petrophysical analysis of the well data was used to define the shale fraction in each stratigraphic unit. CPI logs were used to derive explicit shale percentages within both sandstone units (e.g., 5% shale in the Lower Ness Sandstone) and shale units (e.g., 65% shale in the upper part of the Dunlin Group). This information was then compiled geographically to estimate likely compositions between the wells, i.e., at the fault locations. Example profiles of shale-volume fractions are shown in Fig. 9. 

Prior to the drilling of well 30/9-14, the ca. E-W fault located 350-450 m to the south was regarded as a block-bounding fault (see Fig. 3 for location). The... 

The general analytical methods used in the plant seismic analysis are, except where noted in the following discussion, consistent with current LWR practice. (Ref. 5) The initial analysis described below were performed for the QBE as this is more limiting than the SSE. In these analyses, seismic waves are assumed to propagate vertically. The effects of inclined seismic waves (dependent on fault locations) and building interactions (dependent on the number of modules) are considered site-specific. These effects will be accommodated when site-specific analysis are performed. Also, these analyses include the consideration of codirectional responses from simultaneous time history inputs in three directions. 

When transforming the program, new instmctions were added and as a result the time in which the faults were injected changed. Since the injection time is not proportional to the total execution time, we mapped each fault locating the instraction where the fault was injected (by locating its new PC) and pipeline stage where the fault was manifested. Around 1 % of the total number of faults could not be mapped and were replaced by new faults. 

Potentials of Impedance Spectroscopy for cable fault location... 

Keywords. Scattering parameters the input impedance of the cable Impedance Spectroscopy global optimization technique wire fault location... 

Correlation algorithms have been applied to detect and locate the small discontinuities [5], An intrinsic limitation of this technique is the attenuation and dispersion of the reflected signal that can limit the maximum distance of wire fault detection and can affect the accuracy of fault location. 

MODEL BASED APPROACHES FOR WIRE FAULT LOCATION... 

In [22] a frequency-independent RLGiC parameter for the transmission lines is modeled for the transmission line and the wave-splitting and Green functions techniques are applied to reconstruct the transmission line. The losses of the conductor and dielectric and the frequency dependence of the parameters of the transmission line are neglected, so that this method is not accurate and is suitable for wire fault location only in a simple transmission lines. The transmitted signal is measured to restore the parameters of the transmission line. For that a measurement from both sides is necessary. 

Fig. 3 shows the number of the period in waveform of the amplitude of the cable s input impedance is proportional to the distance to the fault. The peaks in Fig. 4 are smaller for longer cables because of attenuation and dispersion. The measurement deviation for wire fault location depends on the step frequency of the input signals A/and the load impedances. 

Fig. 5 shows the behavior of the absolute deviation of the wire fault location. The maximal absolute deviation is about 30 cm for different cable lengths. It can be optimized by the set-... 

Figure 5. Reconstruction accuracy of wire fault location of the coaxial cable.

A New Algorithm for Wire Fault Location Using Time-Domain Reflectometry, IEEE Sen-... 

Automated wire fault location using impedance spectroscopy and Dilferential Evolution, in... 

Wire Fault Location in Coaxial Cables by Impedance Spectroscopy, IEEE Sensors Journal,... 

Apphcation of iterative deconvolution for wire fault location via leflectometiy, in Instru-... 

Q. Shi, U. Troltzsch, and O. Kanoun, Analysis of the Parameters of a Lossy Coaxial Cable for Cable Fault Location, in 8th International Multi-Conference on Systems. Signals and Devices (SSD), IEEE, 2011, pp. 1. ... 

S.C. Wu, An iterative inversion method for transmission line fault location, PhD thesis. University of Utah, Salt Lake City, 2011. 

All major faults located in regions where strong earthquakes have occurred should be regarded as potentially active unless convincing evidence exists to the contrary (Sherard et al., 1974). In stable areas of the world, little evidence exists of notable fault displacements in the recent past. Nevertheless, an investigation should be carried out to confirm the absence of active faults at or near any proposed major dam in any part of the world. 

The maximum principal stress curve of and F2 faults shows that their stress concentration doesn t appear at one point, while shows as banded area that is about 6 km long around the fault, the intersection of Xiaoyudong fault and this fault locates in the middle of that area, and the stress concentration of F fault is most obvious. 

Figure 3. Key points (related area) on tunnel periphery and fault location.

When a fault locates near the right sidewall, the horizontal displacement of the left sidewall is almost the same as no fault. However, if a fault locates near the crown and right shoulder of the tunnel periphery, the horizontal displacement of the middle point of the left sidewall is as a half as no fault. From the results of the four cases, the fault in surrounding rock mass does not always cause all parts of the surrounding rock displacement increase, for example, the crown fault makes the displacement of the crown increase to the 4 times of the displacement, but makes the middle horizontal displacement of the two sidewalls reduced to 40%, comparing with the no fault case. 

When a fault distributes near the tunnel crown, the tensile stress appears at crown and bottom part is with the maximum tensile stress of 1.5 MPa. When a fault distributes near the tunnel right shoulder, the tensile stress appears near the fault is with the maximum tensile stress of 1.0 MPa. Because of the arch effect, there is no tensile stress area in the tunnel crown part. The worst case in these four cases is that a fault locates near the tunnel right sidewall. In this case, the surrounding rock mass between tunnel periphery and fault not only come into tensile status, but also is with high... 

A fault locates at different locations of tunnel periphery lead to the different influence on the... 

In most instances, the steep fault can be reactivated and normal fault-style movement can be induced regardless of the trend of the fault under such circumstances. Specifically, when a steep bedding fault located in the tension zone of the slope, the reactivated fault showed a normal fault-style movement and formed a back-facing scarp on the slope surface. While, when a steep antithetic fault... 

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