GE 745 Instruction Manual page 219

CHAPTER 6: ACTUAL VALUES
6.3.2.3 Total Harmonic Distortion (THD)
 THD
6.3.2.4 Harmonic Derating Factor
 HARMONIC
DERATING
Note
NOTE
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
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.
PATH: ACTUAL VALUES
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MESSAGE
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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 standard 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 programmed frequency
band (in terms of harmonic number) over which THD is being calculated.
PATH: ACTUAL VALUES
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These actual values are shown only if the harmonic derating function is enabled.
A2 METERING HARMONIC CONTENT

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
A2 METERING HARMONIC...

W1 HARMONIC DERATING
FACTOR: 1.00
W2 HARMONIC DERATING
FACTOR: 1.00
W3 HARMONIC DERATING
FACTOR: 1.00
A2 METERING
THD

HARMONIC DERATING
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6–11