ABB RET670 - Page 165

∠ =






=






=V
ForwardX
ForwardR
ts
arctan arctan
.
.
59 33
8 19
82..14°
EQUATION14058 V1 EN (Equation 28)
frequency of V
ts
= 50 Hz
I I
I
I
A
s
CTs
CTp
50 50
10459
1
9000
1 162= × = × = .
EQUATION14059 V1 EN (Equation 29)
∠I
50s
= 0º
frequency of I
50s
= 50 Hz
It I
I
I
A
fs
CTs
CTp
tf= × = × =10459
1
9000
1 162.
EQUATION14062 V1 EN (Equation 30)
∠I
tfs
= 0º
frequency of I
tf
= 50 Hz
• 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 = 10.74 kV
• CURRENT = 20918 A
• R = 7.37%
• X = 53.40%
• ROTORANG = -3.09 rad
Note that these values identify a point inside the lens characteristic, in the zone 2, that
is close to the point RE. 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 V
V
V
V
ts t FwdZ
VT s
VT p
= × × = × × =0 9 0 9 11931
0 1
13 8
77 81. .
.
.
.
,
,
,
EQUATION14063 V1 EN (Equation 31)
1MRK 504 165-UUS - Section 11
Testing functionality by secondary injection
Transformer protection RET670 2.2 ANSI 159
Commissioning manual