ABB RET670 Commissioning Manual page 164

Relion 670 series, transformer protection
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Section 11
Testing functionality by secondary injection
158
V
VT s
,
V
0 9
.
V
=
×
×
ts
t RZ
,
1
V
VT p
,
EQUATION14066 V1 EN-US
ForwardX
V
arctan
=
ts
ForwardR
EQUATION14058 V1 EN-US
frequency of V
= 50 Hz
ts
I
CTs
I
I
10459
=
×
=
50
s
50
I
CTp
EQUATION14059 V1 EN-US
∠I
= 0º
50s
frequency of I
= 50 Hz
50s
I
It
I
CTs
10459
=
×
=
tf
fs
I
CTp
EQUATION14062 V1 EN-US
∠I
= 0º
tfs
frequency of I
= 50 Hz
tf
Check that the service values (VOLTAGE, CURRENT, R(%), X(%)) are
according to the injected quantities and that ROTORANG is close to 3.14 rad.
For this particular injection the service values are:
VOLTAGE = 1.29 kV
CURRENT = 20918 A
R = 0.89%
X=6.42%
ROTORANG = -3.04 rad
Note that these values identify a point inside the lens characteristic in zone 1,
that is close to the boundary between zone 1 and zone 2. The START is issued,
but no TRIP is performed.
Execution of the dynamic test
The test may be performed by using two states of a sequence tool that is a basic
feature of test sets.
State 1: pre-test condition.
Steady voltage and current are applied in order to get a steady high impedance,
that is a point in the plane R-X which is far away from the lens characteristic.
Define the following three-phase symmetrical quantities (the phase angle is
related to phase L1):
V
VT s
,
V
0 9
.
V
=
×
×
ts
t RZ
,
1
V
VT p
,
EQUATION14066 V1 EN-US
0 1
.
0 9 1435
.
9 36
.
V
=
×
×
=
13 8
.
59 33
.
arctan
82. . 14°
 =
 =
8 19
.
1
= .
1 162
A
×
9000
1
A
1 162
.
×
=
9000
0 1
.
0 9 1435
.
9 36
.
V
=
×
×
=
13 8
.
1MRK 504 165-UEN A
(Equation 47)
(Equation 48)
(Equation 49)
(Equation 50)
GUID-98707DB3-9A1A-4458-9704-25F8FCB94B79 v1
(Equation 51)
Transformer protection RET670 2.2 IEC
Commissioning manual

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