GE Multilin
745 Transformer Management Relay
6-9
6 ACTUAL VALUES
6.3 A2 METERING
6
c) TOTAL HARMONIC DISTORTION (THD)
PATH: ACTUAL VALUES
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A2 METERING
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HARMONIC CONTENT
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2ND HARMONIC
THD is calculated and displayed. Every THD value is calculated as the ratio of the RMS value of the sum of the squared
individual harmonic amplitudes to the rms value of the fundamental frequency. The calculations are based on IEEE stan-
dard 519-1986.
The actual values messages display the total harmonic distortion for phase A, B, and C currents for Windings 1 through 3,
expressed as a percentage of the fundamental frequency component. The numbers in parentheses indicate the pro-
grammed frequency band (in terms of harmonic number) over which THD is being calculated.
d) HARMONIC DERATING FACTOR
PATH: ACTUAL VALUES
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A2 METERING
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HARMONIC CONTENT
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HARMONIC DERATING
The Harmonic Derating Factor for each of the windings shows the effect of non-sinusoidal load currents on power trans-
former’s rated full load current. The calculations are based on ANSI/IEEE standard C57.110-1986. The actual values mes-
sages display the harmonic derating factor for Windings 1 through 3.
THD
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W1 THDa (2nd-21st):
0.0% ƒo
W1 THDb (2nd-21st):
0.0% ƒo
W1 THDc (2nd-21st):
0.0% ƒo
W2 THDa (2nd-21st):
0.0% ƒo
W2 THDb (2nd-21st):
0.0% ƒo
W2 THDc (2nd-21st):
0.0% ƒo
W3 THDa (2nd-21st):
0.0% ƒo
W3 THDb (2nd-21st):
0.0% ƒo
W3 THDc (2nd-21st):
0.0% ƒo
HARMONIC DERATING
[ENTER] for more
W1 HARMONIC DERATING
FACTOR: 1.00
W2 HARMONIC DERATING
FACTOR: 1.00
W3 HARMONIC DERATING
FACTOR: 1.00
ENTER
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