P.8.13
Date Code 20151029 Protection Manual SEL-411L Relay
Oscillography, Events, and SER
Oscillography
not configured for traveling wave fault location, then IRRFO is
NA. For example, if only Terminal W was configured for
traveling wave fault location (by setting TWCOMI = N or
TWALTI = 0), then IRRFO is NA for Terminal X.
The relay uses the traveling wave method to calculate the fault location if a
64 kbps channel is available. If your installation does not include 87L current
differential protection (or the channel is unavailable), use the local and remote
peak information to compute the fault location manually (see Example 8.3).
EXAMPLE 8.3
Assume you collected the following B-phase information from the
remote end's header information:
TPKB (peak time stamp) = 21/08/2013,14:04:37.656356294
TWSPL (selected phase) = 2
Use the following information from the local relay header file (see
Figure 8.6):
TWLL = Line Length for TW Fault Location (0.2-1000) : 189.03
TPKL = 14:04:37.656871414 (Use the B-phase value because TWSPL = 2)
TPKR = 14:04:37.656356294 (Use the B-phase value because TWSPL = 2)
LPVEL = Propagation Vel. in pu of Speed of Light (0.1-1) : 0.99081
C = 186282.397 mi/sec (because the Line Length Units [mi,km] = MI)
NOTE: If Line Length Units (mi,km) = KM, use C = 299792.458 km/sec
Use Equation 3.65 and calculate the fault location as follows:
FL = (TWLL / 2) + (TPKL - TPKR) o C o (LPVEL / 2).
FL = (189.03/ 2) + (14:04:37.656871414 - 14:04:37.656356294) o 186282.397 o
(0.99081/2)
FL = 142.053 mi
Generating Traveling Wave (TW) Data Oscillograms
The trigger event method described in Triggering Data Captures and Event
Reports can be used to trigger TW COMTRADE reports. For each trigger, the
relay records high-resolution and traveling wave COMTRADE reports. These
two types of reports (HR and TW) will have the same index number.
Retrieving TW Data Oscillograms
Use a computer terminal emulation program and the FILE commands at any
communications port to retrieve the stored TW data capture from the relay file
structure. You can also use
ACSELERATOR QuickSet.
Visualizing TW Data Oscillograms
Many programs read the binary TW COMTRADE files. The SEL-5601
software can read the binary TW COMTRADE files and display the time
stamp in nanosecond resolution. Figure 8.7 shows an example of a TW
COMTRADE file using SEL-5601.
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