Alstom Reason RPV311, Техническое руководство

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RPV311 Chapter 9
– TW Fault Locator
RPV311-TM-EN-6 177
3 TW FAULT LOCATION INFORMATION
3.1 MAXIMUM NUMBER OF LINES MONITORED BY THE TW FAULT LOCATOR
If the voltage is sourced from a bus VT you only need one RA333 to capture TWs from all the lines
connected to that bus, however simultaneous or consecutive faults (less than 2 minutes apart) on lines
connected to that bus will not be captured.. Moreover, it is possible to connect up to 4 modules RA333 to one
processing unit RPV311.
3.2 ACCURACY AND TWFL WITH CVTS
The accuracy of the TWFL lies mostly in the proper identification of the traveling wave in both ends of the
line and the accuracy of the GPS clock. The theoretical best possible accuracy is ± 60 meters using a GPS
clock with 100ns accuracy, as the GPS accuracy enhances the fault location becomes more accurate. The
average error is ± 150 meters.
CVTs and bus composition would not influence on the correct time location of the traveling wave and that is
the most important factor in the fault location using TW, as shown in the equation presented below. The CVT
and bus composition could affect the quality of the TW registered and it could make it difficult for the
automatic locator algorithm to locate the fault, but the traveling wave will be registered in the COMTRADE
file, it will be just a matter of correctly pointing it out. Reason features an option for locating the fault in those
cases, explained in Chapter 12, item 2.4 - TW Fault Locator, where the user tells the software where the
wavefront is and then the software calculates the fault location based on that point.
3.3 UNDERGROUND AND OVERHEAD CABLES
There are no restraints regarding the fact that the cable is underground. In the calculation of the fault
location, there is a parameter k (as presented in the fault location formula aforementioned) that depends on
the physical characteristics of the wire. When the TW fault locator method is used on combination of cable
the k parameter becomes the mean value of the k of each separate wire, it will not represent the actual k of
the line at the faults location, it is an approximation. The method will work but with less accuracy.
Note:
The maximum number of RA333 that can be connected to the RPV311 is 4.
The RA333 module has to be connected to the RPV311 processing module before its initialization.
Otherwise a log message will tell the user to reboot the device.