Verifying The Settings - ABB RET670 Commissioning Manual

Section 10
Testing functionality by secondary injection
generators, with stator windings split into two groups per phase, when each group is equipped
with current transformers. The protection function performs a simple summation of the currents
of the two channels I3P1 and I3P2.
10.4.12.1

Verifying the settings

The test of the out-of-step protection function is made to verify that the trip is issued if the
following events happen.
• the impedance, seen by the function, enters the lens characteristic from one side and leaves it
from the opposite side
• the trip is issued according to the settings
The tripping zone needs to be detected and confirmed. The test may be performed by taking into
account the following key points that are shown in Figure 31:
• the point RE (RE = Receiving End)
• the intersection between the line segment SE-RE and the X-line, which is defined through the
setting
• the point SE (SE = Sending End)
IEC10000141 V2 EN-US
Figure 31:
The test of the out-of-step protection function requires the injection of the analog quantities for a
quite long time. The rating of the analogue channels is considered in order to avoid any hardware
damage. The test current is lower than the continuous permissive overload current I
protection current channels of the transformer module.
If the rated secondary current I
I I
≤
ts ovrl
EQUATION14041 V1 EN-US
If the CT of the generator has ratio 9000/1 A, then in primary values
116
ReachZ1
Trajectory of the impedance Z(R, X) for the injected current with two
components: a 50 Hz component and a 49.5 Hz current component
rs
4 I 4 A
= × =
rs
TripAngle and tBreaker
I = I(50 Hz) + I(49.5 Hz)
of the analog channel is 1 A, then the maximum current test I
1MRK 504 154-UUS B
GUID-708C4033-3111-481F-9868-FF207C18C9F9 v1
of the
ovrl
is
ts
(Equation 1)
Commissioning manual