GE L30 Instruction Manual page 497

CHAPTER 6: ACTUAL VALUES
This menu displays metered values for real, reactive, and apparent power, as well as power factor. The "SRC 1" text is
replaced by the name programmed by the user for the associated source (see
).
SOURCES
When VTs are configured in wye, the L30 calculates power in each phase and three-phase power is measured as
When VTs are configured in delta, the L30 does not calculate power in each phase and three-phase power is measured as
where
S is the apparent power
V , V , V , I , I , I are phase voltage and phase current phasors
A B C A B C
V and V are phase-to-phase voltage phasors
AB CB
Î is the conjugate of I
6.4.3.7 Frequency metering
ACTUAL VALUES  METERING  SOURCE SRC 1  FREQUENCY
 FREQUENCY
 SRC 1
The metered frequency values are displayed in this menu. The "SRC 1" text is replaced by the name programmed by the
user for the associated source (see
is measured via software-implemented zero-crossing detection of an AC signal. The signal is either a
SOURCE FREQUENCY
Clarke transformation of three-phase voltages or currents, auxiliary voltage, or ground current as per source configuration
(see the
SYSTEM SETUP  POWER SYSTEM
frequency measurement is passed through a validation filter that eliminates false readings due to signal distortions and
transients.
If the 87L function is enabled, then dedicated 87L frequency tracking is engaged. In this case, the relay uses the
 TRACKING FREQUENCY  TRACKING FREQUENCY
6.4.3.8 Current harmonics and THD metering
ACTUAL VALUES  METERING  SOURCE SRC 1  CURRENT HARMONICS
 CURRENT HARMONICS
 SRC 1
This menu displays metered current harmonics values. The "SRC 1" text is replaced by the name was programmed for the
associated source (see
SETTINGS  SYSTEM SETUP  SIGNAL SOURCES
for the total harmonic distortion (THD) and 2nd to 25th harmonics per phase.
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
SRC 1 POWER FACTOR

φb: 1.000
SRC 1 POWER FACTOR

φc:
1.000
S = V x Î + V x Î + V
A A B B
S = V x Î + V
AB A CB
SRC 1 FREQUENCY:

0.00 Hz
SETTINGS  SYSTEM SETUP  SIGNAL SOURCES
settings). The signal used for frequency estimation is low-pass filtered. The final
value for all computations, overriding the
SRC 1 THD Ia: 0.0

Ib: 0.0 Ic: 0.0%
SRC 1 2ND Ia: 0.0

Ib: 0.0 Ic: 0.0%
SRC 1 3RD Ia: 0.0

Ib: 0.0 Ic: 0.0%

SRC 1 25TH Ia: 0.0

Ib: 0.0 Ic: 0.0%
SETTINGS  SYSTEM SETUP  SIGNAL
x Î
C C
x Î
C
).
SOURCE FREQUENCY
). Current harmonics are measured for each source
METERING
Eq. 6-1
Eq. 6-2
6
METERING
value.
6-19