ABB RELION REB500 Technical Manual page 129

1MRK 505 406-UEN B
Maximum voltage level for monitoring (determination of whether plant is de-
energized)
Choice of operating mode
Measuring period (delay before issuing enable)
Reset delay
Choice of phase for monitoring on the busbar side
Choice of phase for monitoring on the line side
Monitoring the conditions for synchronism (maxVoltDif, maxPhaseDif
and maxFreqDif)
The determination of voltage difference, phase-shift and frequency difference is performed
for just one of the phases of the three-phase system. For this purpose, the analogue values are
first filtered by a digital Fourier bandpass filter (to obtain the fundamentals) and then the
orthogonal components UBus and ULine are derived.
The phase-shift dPh between the voltages and the difference between their amplitudes dU are
calculated from the corresponding vector diagram in the complex plane.
Synchrocheck function
Monitoring the conditions for synchronism:
IEC19000451 V1 EN-US
Figure 47: Monitoring the conditions for synchronism
where:
• UBus, ULine : complex vectors for UBus and ULine
• ωB, ωL : angular velocities for U bus and U line
• dU = U bus − U line
• dPhi = PhiB − PhiL
Bay protection functions REB500
Technical manual
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18000046-IEC19000451-1-en.vsdx
Section 5
Bay protection functions
maxVoltage
Operat.-Mode
supervisTime
t-Reset
uBusInp-Ph
uLineInp-Ph
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