GE C70 User Manual

CHAPTER 6: ACTUAL VALUES METERING
C70 CAPACITOR BANK PROTECTION AND CONTROL SYSTEM – INSTRUCTION MANUAL 6-19
6
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 SETTINGS  SYSTEM SETUP  SIGNAL
SOURCES
).
When VTs are configured in wye, the C70 calculates power in each phase and three-phase power is measured as
S = V
A
x Î
A
+ V
B
x Î
B
+ V
C
x Î
C
Eq. 6-1
When VTs are configured in delta, the C70 does not calculate power in each phase and three-phase power is measured as
S = V
AB
x Î
A
+ V
CB
x Î
C
Eq. 6-2
where
S is the apparent power
V
A
, V
B
, V
C
, I
A
, I
B
, I
C
are phase voltage and phase current phasors
V
AB
and V
CB
are phase-to-phase voltage phasors
Î is the conjugate of I
6.4.2.7 Frequency metering
ACTUAL VALUES  METERING  SOURCE SRC 1  FREQUENCY
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
SETTINGS  SYSTEM SETUP  SIGNAL SOURCES).
SOURCE FREQUENCY is measured via software-implemented zero-crossing detection of an AC signal. The signal is either a
Clarke transformation of three-phase voltages or currents, auxiliary voltage, or ground current as per source configuration
(see the
SYSTEM SETUP  POWER SYSTEM settings). The signal used for frequency estimation is low-pass filtered. The final
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
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). Current harmonics are measured for each source
for the total harmonic distortion (THD) and 2nd to 25th harmonics per phase.

SRC 1 POWER FACTOR
φb: 1.000

SRC 1 POWER FACTOR
φc: 1.000
 FREQUENCY
 SRC 1

SRC 1 FREQUENCY:
0.00 Hz
 CURRENT HARMONICS
 SRC 1

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%

GE C70 Specifications

General

Brand	GE
Model	C70
Category	Protection Device
Language	English