Synchrocheck - GE L30 Instruction Manual

METERING
6.4.3.9 Voltage harmonics and THD metering
ACTUAL VALUES  METERING  SOURCE SRC 1  VOLTAGE HARMONICS
 VOLTAGE HARMONICS
 SRC 1
This menu displays metered voltage harmonics values. The "SRC 1" text is replaced by the programmed name for the
associated source (see the
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 = 2πf is the angular frequency based on the system frequency (50 or 60 Hz)
0
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:
6
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:
Voltage harmonics are calculated only for Wye connected phase VTs. Ensure that the
 VOLTAGE BANK F5  PHASE VT XX CONNECTION

6.4.4 Synchrocheck

ACTUAL VALUES  METERING  SYNCHROCHECK  SYNCHROCHECK 1(4)
 SYNCHROCHECK 1

6-20
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%
SETTINGS  SYSTEM SETUP  SIGNAL SOURCES
SYNCHROCHECK 1 DELTA

VOLT: 0.000 kV
SYNCHROCHECK 1 DELTA

FREQ: 0.00 Hz
SYNCHROCHECK 1

DELTA PHASE:
SYNCHROCHECK 1

SYNSCP D_PH: 0.0°
menu).
setting is "Wye" to enable voltage harmonics metering.
0.0°
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUES
Eq. 6-3
Eq. 6-4
SYSTEM SETUP  AC INPUTS