It I
I
I
A
fs
CTs
CTp
tf= × = × =10459
1
9000
1 162.
EQUATION14062 V1 EN (Equation 60)
∠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 = 5.31 kV
• CURRENT = 20918 A
• R = -0.26%
• X = -26.65%
• ROTORANG = -3.06 rad
Note that these values identify a point inside the lens characteristic in zone 1 that is
close to the point SE. 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 RvsZ
VT s
VT p
= × × = × × =0 9 0 9 5899
0 1
13 8
38 47. .
.
.
.
,
,
,
EQUATION14067 V1 EN (Equation 61)
29.60
arctan 180 arctan 180 90.56
0.29
ts
ReverseX
V
ReverseR
Ð = - ° = - ° = - °
æ ö æ ö
ç ÷ ç ÷
è ø è ø
EQUATION14068 V1 EN (Equation 62)
frequency of V
ts
= 50 Hz
I
50s
= 0 A
I
tfs
= 0 A
• State 2: main test step.
Define the following three-phase symmetrical quantities (the phase angle is related to
phase L1):
Section 11 1MRK 504 165-UUS -
Testing functionality by secondary injection
166 Transformer protection RET670 2.2 ANSI
Commissioning manual
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