The
DeadbandtDiff setting range is ±200-1000 μs. If the accumulated time delay of up to four
changes is greater then the set value for
DeadbandtDiff but below the set value for
MaxtDiffLevel, no action is taken. When the fifth time delay change occurs, the protection
function is blocked even if the maximum deviation is not reached. This restriction is included
because of measuring inaccuracy with too many consecutive, accumulated time delay
changes. After blocking, the communication set-up must be checked before restarting.
IEC10000062 V1 EN-US
Figure 6:
Setting DeadbandtDiff in PCM600
Figure
shows an oscillogram example of deadband, measured change in time delay and
scattering (deviation in calculation) within the set
DeadbandtDiff value.
D
dt
IEC07000226-1-en.vsdx
IEC07000226 V1 EN-US
Figure 7:
An oscillogram example showing deadband (D), measured change in time
delay (dt) and scattering
D
DeadbandtDiff = ±200 μs
dt
Measured time delay change = ±200 μs
Scattering
Random fluctuations in time delay due to, for example, varying switching time in
multiplexers that induces jitter and wander.
Section 2
1MRK 505 382-UEN E
Telecommunication networks and line differential protection
16
Communication set-up, 670/650 series
Application Guide
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Summary of Contents for Relion 670 series
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