5-32
745 Transformer Management Relay
GE Multilin
5.4 S2 SYSTEM SETUP
5 SETPOINTS
5
5.4.4 ONLOAD TAP CHANGER
PATH: SETPOINTS
ÖØ
S2 SYSTEM SETUP
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ONLOAD TAP CHANGER
This section contains the settings to configure the tap position input. The 745 accepts a resistive input from the tap changer
control circuitry, which is used in the 745 to dynamically correct for CT ratio mismatch based on the dynamically changing
voltage ratio of the transformer. Thus, the percent differential function of the device can be set for greater sensitivity. See
Section 5.2.2 Dynamic CT Ratio Mismatch Correction on page 5–5 for more details on the tap position input.
•
WINDING WITH TAP CHANGER
: Enter the winding with the tap changer. Enter 'None' for a transformer with no
onload tap changer, or to disable this feature.
•
MINIMUM TAP POSITION VOLTAGE
: Enter the voltage at the lowest tap position. This is an auto-ranging setpoint
dependent on
S2 SYSTEM SETUP
Ö
TRANSFORMER
ÖØ
LOW VOLTAGE WINDING RATING
; see ranges in the table below.
•
VOLTAGE INCREMENT PER TAP
: Enter the voltage increment for each tap. The range is affected by the setpoint.
This is an auto-ranging setpoint dependent on the
S2 SYSTEM SETUP
Ö
TRANSFORMER
ÖØ
LOW VOLTAGE WINDING RAT-
ING
value; see ranges in the following table
•
RESISTANCE INCREMENT PER TAP
: Enter the resistance increment that the 745 will see for each tap increment. The
maximum resistance value for the top tap is 5 K
Ω
5.4.5 HARMONICS
PATH: SETPOINTS
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S2 SYSTEM SETUP
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HARMONICS
The 745 calculates the individual harmonics in each of the phase current inputs up to the 21
st
harmonic. With this informa-
tion, it calculates an estimate of the effect of non-sinusoidal load currents on the transformer rated full load current. These
calculations are based on ANSI/IEEE Standard C57.110-1986, and require information that is often only available from the
transformer manufacturer’s test report, including the three-phase resistance of each winding and the load loss at rated
load. The harmonic derating factor will only be valid if this information has been entered correctly.
ONLOAD TAP CHANGER
[ENTER] for more
WINDING WITH TAP
CHANGER: None
Range: None, Winding 1, Winding 2, Winding 3
NUMBER OF TAP
POSITIONS: 33
Range: 2 to 50 in steps of 1
MINIMUM TAP POSITION
VOLTAGE: 61.0 kV
Range: Dependent on
LOW VOLTAGE WINDING RATING
setpoint; see description below.
VOLTAGE INCREMENT
PER TAP: 61.0 kV
Range: Dependent on
LOW VOLTAGE WINDING RATING
setpoint; see description below.
RESISTANCE INCREMENT
PER TAP: 33
Ω
Range: 10 to 500
Ω
in steps of 1
SETTING
LOW VOLTAGE WINDING RATING
ABOVE 5 KV
1 KV TO 5 KV
BELOW 1 KV
MINIMUM TAP POSITION VOLTAGE
0.1 to 2000.0
in steps of 0.1 kV
0.01 to 200.00
in steps of 0.01 kV
0.001 to 20.000
in steps of 0.001 kV
VOLTAGE INCREMENT PER TAP
0.01 to 20.00
in steps of 0.01 kV
0.001 to 2.000
in steps of 0.001 kV
0.0001 to 0.2000
in steps of 0.0001 kV
HARMONICS
[ENTER] for more
HARMONIC DERATING
ESTIMATION: Disabled
Range: Enabled, Disabled
THD MINIMUM HARMONIC
FUNCTION: 2nd
Range: 2nd, 3rd, 4th,..., 21st
THD MAXIMUM HARMONIC
FUNCTION: 2nd
Range: 2nd, 3rd, 4th,..., 21st
ENTER
ESCAPE
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Содержание TRANSFORMER MANAGEMENT RELAY 745
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