6-8
745 Transformer Management Relay
GE Multilin
6.3 A2 METERING
6 ACTUAL VALUES
6
6.3.2 HARMONIC CONTENT
a) MAIN MENU
PATH: ACTUAL VALUES
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A2 METERING
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HARMONIC CONTENT
The 745 can determine the harmonic components of every current that it measures. This allows it to calculate total har-
monic distortion (THD) as well as a harmonic derating factor that can be used to adjust phase time overcurrent protection to
account for additional internal energy dissipation that arises from the presence of harmonic currents.
b) HARMONIC SUB-COMPONENTS
PATH: ACTUAL VALUES
ÖØ
A2 METERING
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HARMONIC CONTENT
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2ND HARMONIC
The 745 is capable of measuring harmonic components up to a frequency of 21 times nominal system frequency. An actual
value is calculated for each phase of each monitored winding. The example above shows what is displayed in a typical
case for harmonic components (in this case the second harmonic). Similar displays exist for all harmonics up to the 21
st
.
The second harmonic magnitude for each phase current of Windings 1 through 3 are displayed. Values are expressed as a
percentage of magnitude of the corresponding fundamental frequency component.
HARMONIC CONTENT
[ENTER] for more
2nd HARMONIC
[ENTER] for more
See below.
↓
21st HARMONIC
[ENTER] for more
THD
[ENTER] for more
See page 6–9.
HARMONIC DERATING
[ENTER] for more
See page 6–9.
2nd HARMONIC
[ENTER] for more
W1 (% f0) H2a: 0.0
H2b: 0.0
H2c: 0.0
W2 (% f0) H2a: 0.0
H2b: 0.0
H2c: 0.0
W3 (% f0) H2a: 0.0
H2b: 0.0
H2c: 0.0
ENTER
ESCAPE
ð
ð
MESSAGE
ESCAPE
MESSAGE
ESCAPE
MESSAGE
ESCAPE
ENTER
ESCAPE
ð
ð
MESSAGE
ESCAPE
MESSAGE
ESCAPE
Содержание TRANSFORMER MANAGEMENT RELAY 745
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