6-24
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
METERING
CHAPTER 6: ACTUAL VALUES
6
6.4.6 Tracking frequency
ACTUAL VALUES
METERING
TRACKING FREQUENCY
The tracking frequency displays here. The frequency is tracked based on configuration of the reference source. The
TRACKING FREQUENCY
is based on positive sequence current phasors from all line terminals and is synchronously adjusted
at all terminals. If currents are below 0.125 pu, then the
NOMINAL FREQUENCY
is used.
6.4.7 Frequency rate of change
ACTUAL VALUES
METERING
FREQUENCY RATE OF CHANGE 1(4)
The metered frequency rate of change for the frequency rate of change elements is shown here.
6.4.8 FlexElements
ACTUAL VALUES
METERING
FLEXELEMENTS
FLEXELEMENT 1(8)
The operating signals for the FlexElements are displayed in pu values using the following definitions of the base units.
Table 6-2: FlexElement base units
TRACKING FREQUENCY
TRACKING FREQUENCY:
60.00 Hz
FREQUENCY RATE
OF CHANGE 1
FREQUENCY RATE OF
CHANGE1: 0.00 Hz/s
FLEXELEMENT 1
FLEXELEMENT 1
OpSig:
0.000
Base unit
Description
87L SIGNALS
(Local IA Mag, IB, and IC)
(Diff Curr IA Mag, IB, and IC)
(Terminal 1 IA Mag, IB, and IC)
(Terminal 2 IA Mag, IB and IC)
I
BASE
= maximum primary RMS value of the +IN and –IN inputs
(CT primary for source currents, and 87L source primary current for line differential currents)
87L SIGNALS
(Op Square Curr IA, IB, and IC)
(Rest Square Curr IA, IB, and IC)
BASE = Squared CT secondary of the 87L source
BREAKER ACC ARCING AMPS
(Brk X Acc Arc Amp A, B, and C)
BASE = 2000 kA
2
×
cycle
BREAKER ARCING AMPS
(Brk X Arc Amp A, B, and C)
BASE = 1 kA
2
×
cycle
DCmA
BASE = maximum value of the
DCMA INPUT MAX
setting for the two transducers configured
under the +IN and –IN inputs.
FAULT LOCATION
BASE = Line Length as specified in Fault Report
FREQUENCY
f
BASE
= 1 Hz
FREQUENCY RATE OF CHANGE
df/dt
BASE
= 1 Hz/s
PHASE ANGLE
ϕ
BASE
= 360 degrees (see the UR angle referencing convention)
POWER FACTOR
PF
BASE
= 1.00
RTDs
BASE = 100°C
SENSITIVE DIR POWER
(Sns Dir Power)
P
BASE
= maximum value of 3
×
V
BASE
×
I
BASE
for the +IN and –IN inputs of the sources configured
for the sensitive power directional element(s).
SOURCE CURRENT
I
BASE
= maximum nominal primary RMS value of the +IN and –IN inputs
SOURCE ENERGY
(Positive and Negative Watthours,
Positive and Negative Varhours)
E
BASE
= 10000 MWh or MVAh, respectively
SOURCE POWER
P
BASE
= maximum value of V
BASE
×
I
BASE
for the +IN and –IN inputs