CHAPTER 6: ACTUAL VALUES
METERING
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
6-21
6
6.4.3.9 Voltage harmonics and THD metering
ACTUAL VALUES
METERING
SOURCE SRC 1
VOLTAGE HARMONICS
This menu displays metered voltage harmonics values. The “SRC 1” text is replaced by the programmed name for the
associated source (see the
SETTINGS
SYSTEM SETUP
SIGNAL SOURCES
menu).
To extract the 2nd to 25th voltage harmonics, each harmonic is computed on a per-phase basis, where:
N = 64 is the number of samples per cycle
ω
0
= 2
π
f is the angular frequency based on the system frequency (50 or 60 Hz)
k = 1, 2,..., N – 1 is the index over one cycle for the Fast Fourier Transform (FFT)
m is the last sample number for the sliding window
h = 1, 2,..., 25 is the harmonic number
The short-time Fourier transform is applied to the unfiltered signal:
Eq. 6-3
The harmonics are a percentage of the fundamental signal obtained as a ratio of harmonic amplitude to fundamental
amplitude multiplied by 100%. The total harmonic distortion (THD) is the ratio of the total harmonic content to the
fundamental:
Eq. 6-4
6.4.4 Synchrocheck
ACTUAL VALUES
METERING
SYNCHROCHECK
SYNCHROCHECK 1(4)
VOLTAGE HARMONICS
SRC 1
SRC 1 THD Va: 0.0
Vb: 0.0 Vc: 0.0%
SRC 1 2ND Va: 0.0
Vb: 0.0 Vc: 0.0%
SRC 1 3RD Va: 0.0
Vb: 0.0 Vc: 0.0%
SRC 1 25TH Va: 0.0
Vb: 0.0 Vc: 0.0%
Voltage harmonics are calculated only for Wye connected phase VTs. Ensure that the
SYSTEM SETUP
AC INPUTS
VOLTAGE BANK F5
PHASE VT XX CONNECTION
setting is “Wye” to enable voltage harmonics metering.
SYNCHROCHECK 1
SYNCHROCHECK 1 DELTA
VOLT: 0.000 kV
SYNCHROCHECK 1 DELTA
FREQ: 0.00
Hz
SYNCHROCHECK 1
DELTA PHASE: 0.0°
SYNCHROCHECK 1
SYNSCP D_PH: 0.0°
Содержание L30
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Страница 14: ...1 4 L30 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL FOR FURTHER ASSISTANCE CHAPTER 1 INTRODUCTION 1 ...
Страница 126: ...3 68 L30 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL CONNECT TO D400 GATEWAY CHAPTER 3 INSTALLATION 3 ...
Страница 214: ...4 88 L30 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL FLEXLOGIC DESIGN USING ENGINEER CHAPTER 4 INTERFACES 4 ...
Страница 582: ...7 16 L30 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL TARGETS MENU CHAPTER 7 COMMANDS AND TARGETS 7 ...
Страница 598: ...9 6 L30 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL TESTING CHAPTER 9 COMMISSIONING 9 ...
Страница 622: ...10 24 L30 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL FAULT LOCATOR CHAPTER 10 THEORY OF OPERATION 10 ...
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Страница 678: ...C 6 L30 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL COMMAND LINE INTERFACE APPENDIX C COMMAND LINE INTERFACE C ...
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