ABB Relion REG670, Commissioning Manual

Page: 140 / 262

The previous calculations are in primary values. They are transferred to secondary values to
perform injections by a test set. Primary values are transferred to secondary values by taking
into account the CT ratio and the VT ratio (respectively 9000/1 A and 13.8/0.1 kV in the
example).
The magnitude of the secondary voltages, that are related to the points RE and SE of the R-X
plane, needs to be checked.
RE (R
FwdR
, X
FwdX
):
V V
V
V
V
t FwdZs t FwdZ
VT s
VT p
, ,
,
,
.
.
.
= × = × =
11931
0 1
13 8
86 45
EQUATION14054 V1 EN-US
(Equation 14)
SE (R
RvsR
, X
RvsX
):
V V
V
V
V
t RvsZs t RvsZ
VT s
VT p
, ,
,
,
.
.
.
= × = × =
5899
0 1
13 8
42 75
EQUATION14055 V1 EN-US
(Equation 15)
The tests, which are described in this section, may require voltages that have magnitude equal
to 110% of the previous values. The continuous permissive overload voltage of the protection
voltage channels of the TRM module is 420 V; so the previous voltages may be applied to the
analog channels of the IED continuously. Limitations may be related to the available test set;
the current I
t
was calculated by using a factor 2.5 (instead of the maximum value 4) in order to
reduce the magnitude of the test voltage for the points RE and SE.
Test sets usually do not have a feature to simulate a real network during a power swing and
apply the related analog quantities at the terminal of the generator. The scope of the present
test is not a simulation of a real network. Voltages and currents are supplied in order to
measure an impedance that changes in the time and traverses the plane R-X and, in particular,
the area inside the lens characteristic. The test may be performed by applying:
• Symmetric three-phase voltage at 50 Hz. The magnitude depends on the point of the
characteristic that needs to be verified. The following three main points of the line
segment SE-RE need to be checked:
•
the point RE (R
FwdR
, X
FwdX
)
• a point which is related to the parameter
ReachZ1 (boundary between zone 1 and
zone 2)
• the point SE (R
RvsR
, X
RvsX
)
The phase angle of the test voltages is equal to:
• arctan ( ForwardX/ForwardR) for tests in the quadrant 1 and 2 of the R-X plane
• arctan ( ReverseX/ReverseR) -180° for tests in the quadrant 3 and 4 of the R-X plane
• Symmetric three-phase current, where the current is the summation of two currents that
have the same magnitude, but different frequencies.
I I A
tf
t
I
50
2
20918
2
10459
= = = =
GUID-F02E8D18-FF87-45BE-8142-E8FA19F6966B V1 EN-US
(Equation 16)
The first current I
50
has frequency 50 Hz, magnitude 10459 A (that is, 1.162 A secondary)
and phase angle 0º.
The second current I
tf
has magnitude 10459 A (that is, 1.162 A secondary), phase angle
180º (at the starting time of the test) and frequency:
Section 12 1MRK 502 067-UEN B
Testing functionality by secondary injection
134
Commissioning manual