GE C70 Instruction Manual page 474

METERING
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 C70 calculates power in each phase and three-phase power is measured as
When VTs are configured in delta, the C70 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
A B C A B C
V and V are phase-to-phase voltage phasors
AB CB
Î is the conjugate of I
6.4.2.7 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
SOURCE FREQUENCY
6
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.
6.4.2.8 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
for the total harmonic distortion (THD) and 2nd to 25th harmonics per phase.
6-18
SRC 1 POWER FACTOR

φb:
SRC 1 POWER FACTOR

φc:
S = V
are phase voltage and phase current phasors
SRC 1 FREQUENCY:

0.00 Hz
SETTINGS  SYSTEM SETUP  SIGNAL SOURCES
is measured via software-implemented zero-crossing detection of an AC signal. The signal is either a
settings). The signal used for frequency estimation is low-pass filtered. The final
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 SOURCES
1.000
1.000
x Î + V x Î + V x Î
A A B B C C
S = V x Î + V x Î
AB A CB C

). Current harmonics are measured for each source
C70 CAPACITOR BANK PROTECTION AND CONTROL SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUES
SETTINGS  SYSTEM SETUP  SIGNAL
).
Eq. 6-1
Eq. 6-2