Metering - Hitachi Relion 670 Series Product Manual

Line differential protection RED670
Version 2.2
The current harmonic function monitors the harmonic
distortion and demand distortion values constantly.
Whenever these value crosses their set limit levels, a
warning signal will be initiated. If the warning signal persists
continuously for the set time, an alarm signal will be
generated.
Voltage harmonic monitoring VHMMHAI
Voltage harmonic monitoring function VHMMHAI is used to
monitor the voltage part of the power quality of a system. It
calculates the total harmonic distortion (THD) with respect
to the fundamental signal amplitude which indicates the
voltage signal quality factor.
Additionally, the function is used to calculate the numerical
multiple of rated frequency harmonics amplitude and
harmonic distortion upto the 9
know the predominant harmonic frequencies order and their
amplitudes present in the system. The function also
calculates the crest factor to indicate the effectiveness of
the signal. All calculations in the harmonic monitoring
function are based on IEEE 1459 and IEEE 519-2014
standards.
The voltage harmonic function monitors the harmonic
distortion value constantly. Whenever these value crosses
their set limit levels, a warning signal will be initiated. If the
warning signal persists continuously for the set time, an
alarm signal will be generated.
Fault current and voltage monitoring FLTMMXU
The fault current and voltage monitoring function monitors
and reports the voltage and current values on occurrence of
a trip event.
FLTMMXU function monitors and reports the following
values:
• Maximum peak current of individual phases during the trip
event
• Maximum RMS current of individual phases during the trip
event
• Maximum RMS current of all phases during the trip event
• Fundamental DFT current magnitude and angle of
individual phases at the instant of triggering the function
via input TRIGFLUI
• Fundamental DFT neutral current magnitude and angle at
the instant of triggering the function via input TRIGFLUI
• Fundamental DFT voltage magnitude and angle of
individual phases at the instant of triggering the function
via input TRIGFLUI
• Fundamental DFT neutral voltage magnitude and angle at
the instant of triggering the function via input TRIGFLUI
Fault locator LMBRFLO
The accurate fault locator is an essential component to
minimize the outages after a persistent fault and/or to pin-
point a weak spot on the line.
Hitachi Energy
GUID-868ED1BB-A921-45DE-94C4-0CF23ECD9ADA v2
th
order. It helps the user to
GUID-FD0A598B-7E78-4F49-B927-21D099DD91D4 v1
M13970-3 v13
© 2017 - 2022 Hitachi Energy. All rights reserved
The fault locator is an impedance measuring function giving
the distance to the fault in km, miles or % of line length. The
main advantage is the high accuracy achieved by
compensating for load current and for the mutual zero-
sequence effect on double circuit lines.
The compensation includes setting of the remote and local
sources and calculation of the distribution of fault currents
from each side. This distribution of fault current, together
with recorded load (pre-fault) currents, is used to exactly
calculate the fault position. The fault can be recalculated
with new source data at the actual fault to further increase
the accuracy.
Especially on heavily loaded long lines, where the source
voltage angles can be up to 35-40 degrees apart, the
accuracy can be still maintained with the advanced
compensation included in fault locator.
Single and double ended fault locator SMTRFLO
An accurate fault locator is an essential component to
minimize the outage time after a persistent fault and/or to
pin-point a weak spot on the line.
The fault locator is an impedance measuring function
providing the distance to the fault in km, miles or % of line
length. This functionality provides both single and two
ended based fault location.
The high accuracy of the single ended method is achieved
by compensating for load current and for the mutual zero-
sequence effect on double circuit lines.
The compensation includes setting of the remote and local
sources and calculation of the distribution of fault currents
from each side. This distribution of fault current, together
with recorded load (pre-fault) currents, is used to exactly
calculate the fault position. The fault can be recalculated
with new source data to further increase the accuracy.
Especially on heavily loaded long lines, where the source
voltage angles can be up to 35-40 degrees apart, the
accuracy can be still maintained with the advanced
compensation included in fault locator.
The two ended fault locator is based on both local and
remote voltages and currents. The remote end signals are
received using the LDCM (2Mbps). The signals must be
time synchronized absolutely. The functionality requires the
line length, positive sequence resistance, reactance and
line charging susceptance of the line, which are provided as
the function settings.

17. Metering

Pulse-counter logic PCFCNT
Pulse-counter logic (PCFCNT) function counts externally
generated binary pulses, for instance pulses coming from
1MRK 505 379-BEN R
GUID-3AECD052-CC1E-411E-9631-AC27B9738BA6 v2
M13394-3 v7
57