ABB RET670 Commissioning Manual page 158

Section 11
Testing functionality by secondary injection
152
ForwardX

V arctan
∠ =

ts
ForwardR

EQUATION14058 V1 EN-US
frequency of V = 50 Hz
ts
I
I I CTs
10459
= × =
50 s 50
I
CTp
EQUATION14059 V1 EN-US
∠I
=0°
50s
frequency of I = 50 Hz
50s
I
CTs
It I 10459
= × =
tf
fs
I
CTp
EQUATION14062 V1 EN-US
∠I
=0°
tfs
frequency of I = 50 Hz
tfs
• Check that the service values (VOLTAGE, CURRENT, R(%), X(%)) are
according to the injected quantities and that ROTORANG is close to 0 rad.
For this particular injection the service values are:
• VOLTAGE = 13.12 kV
• CURRENT = 20918 A
• R = 9.01%
• X = 65.27%
• ROTORANG = 0.04 rad
Note that these values identify a point outside the lens characteristic, even if it is
close to the point RE. Neither START nor TRIP is issued.
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.
This is a point in the plane R-X that 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 1 1 . V
= × ×
ts t FwdZ ,
V
VT p ,
EQUATION14057 V1 EN-US
ForwardX

V arctan
∠ =

ts
ForwardR

EQUATION14058 V1 EN-US
59 33 .
  
arctan 82. . 14°
 =  =

8 19 .
  
1
A
= . 1 162
×
9000
1
1 162 . A
× =
9000
0 1 .
1 1 11931 . 95 1 .
= × × =
13 8 .
59 33 .
  
arctan 82. . 14°
 =  =

8 19 .
  
1MRK 504 165-UEN A
GUID-0B73C849-107D-40DC-80BB-31CD441BF69A v1
V
Transformer protection RET670 2.2 IEC
Commissioning manual
(Equation 18)
(Equation 19)
(Equation 20)
(Equation 21)
(Equation 22)