Toshiba GR200 Series - 4.6.3 Line-outage check; (i) Voltage conditions

6F2S1914 (0.49)
GRL200 (Soft 033 & 037)
- 805 -
4.6.3 Line-outage check
(i) Voltage conditions
In the SYNCHK function the OVr, OVi, UVr, and UVi elements are used to verify the line-
condition. For example, when the user wishes to connect an incoming-line (i.e., transmission
line) with the running-line (i.e., a busbar), the voltage conditions on either lines may be
examined prior to connection. Alternatively, the absence of voltage on both lines may be
required before connection. In order to provide this functionality, the SYNCHK function has
four check zones to test for the line being either in-service or out-of-service; the four zones are
illustrated in Figure 4.6-7.
DRDI
LRDI
LRLI
DRLI
Setting [UVI1]
Setting [OVI1]
Setting [UVR1]
Vi on the incoming line
Vr on the running line
Setting [OVR1]
Figure 4.6-7 Four voltage conditions examined in SYNCHK_Ry1
For example, “DRLI” zone covers the case when the running-line is out-of-service (DR)
and the incoming-line is in-service (LI). Table 4.6-4 exemplifies the areas in accordance with
the voltage conditions.
Table 4.6-4 Four voltage conditions and zones
Voltage condition
1
2
3
4
Area
D
○
R L
○
I
L
○
R L
○
I
D
○
R D
○
I
L
○
R D
○
I
○
R unning line (Vr)
(Dead)
(Live)
(Dead)
(Live)
○
I ncoming line (Vi)
(Live)
(Live)
(Dead)
(Dead)
Figure 4.6-8 and Figure 4.6-9 show the voltage-presence (or voltage-absence) check logic
used in the SYNCHK_Ry1 and Ry2 functions.