Table of Contents
Advertisement
[50/51G.En_VTS_Blk]
[VTS.En]
[VTS.Alm]
U
(present measure)
0
I
(present measure)
01
[50/51G1.Opt_Dir] ≠ 0
[BI_En_VT]
Figure 3.5-4 Logic diagram of the directional element for the No.1 ROC1 protection
Where:
[50/51G1.Opt_Dir] is the setting which is used to select the directional mode (non -directional,
forward, reverse) of the directional element for the stage 1 ROC protection;
[VTS.En] is the logic setting of the protection voltage transformer supervision function;
[50/51G.En_VTS_Blk] is the logic setting of the function which blocks all the 1ROC protective
elements that relate to the voltage measurement when the voltage transformer is failed;
[BI_En_VT] is the binary input for denoting the local VT is in service;
[VTS.Alm] is the alarm signal of the protection voltage transformer supervision.
3.5.4 Harmonic Blocking Element for ROC Protection
To prevent maloperation of the zero sequence overcurrent protection when the transformer is
energized without any load, this relay provides a 2
a problem.
The percent threshold of the 2
through the setting [50/51G.K_Hm2].
When the fundamental current is greater than the setting [50/51G.3I0_Rls_HmBlk], the harmonic
blocking element for the zero sequence protection is released.
The following figure shows the logic diagram of the harmonic blocking element for the stage 1
zero sequence overcurrent protection.
Figure 3.5-5 Logic diagram of the No.1 ROC1 harmonic blocking element
Where:
[50/51G1.En_Hm_Blk] is the logic setting of the harmonic blocking element;
[50/51G.K_Hm2] is the percent setting of the harmonic blocking element;
[50/51G.3I0_Rls_HmBlk] is the current setting for releasing the harmonic blocking element;
"I
" is the No.1 zero sequence current;
01
PCS-9611 Feeder Relay
Zero Sequence
Direction Check
nd
harmonic blocking element to the fundamental wave can be set
I
> [50/51G.3I0_Rls_HmBlk]
01
|I
/I
| > [50/51G.K_Hm2]
012
01
[50/51G1.En_Hm_Blk]
Date: 2014-04-08
&
nd
harmonic blocking function for resolving such
&
50/51G1.HmBlk
3 Operation Theory
50/51G1.Dir
3-23
Advertisement
Chapters
Table of Contents
