NR Electric PCS-9611, Instruction Manual

Page: 49 / 300

3 Operation Theory
PCS-9611 Feeder Relay
3-13
Date: 2014-04-08
[50/51P1.En_Hm_Blk]
I
max
> [50/51P.I_Rls_HmBlk]
&
50/51P1.HmBlk_A
[50/51P.Opt_Hm_Blk]
|Ib
2
/Ib
1
| > [50/51P.K_Hm2]
|Ic
2
/Ic
1
| > [50/51P.K_Hm2]
|Ia
2
/Ia
1
| > [50/51P.K_Hm2]
|I
max2
/Ia
1
| > [50/51P.K_Hm2]
1
3
2
Figure 3.3-9 Logic diagram of the OC1 phase A harmonic blocking element
Where:
[50/51P1.En_HarmBlk] is the logic setting of the harmonic blocking element of the stage 1
overcurrent protection;
[50/51P.K_Hm2] is the percent setting of the harmonic blocking element for OC protection;
[50/51P.I_Rls_HmBlk] is the current setting for releasing the harmonic blocking element;
[50/51P.Opt_Hm_Blk] is the setting for selecting the harmonic blocking criterion;
“Ix
1
” (x: a, b or c) is the fundamental current; “Ix
2
” (x: a, b or c) is the 2 nd
harmonic current;
“Imax” is the maximum phase current; “Imax
2
” is the maximum 2
nd
harmonic current.
3.3.6 Heavy Current Blocking Element
If the setting [50P/51P.En_CCE] is set as
“1” and any phase current is greater than the setting
[50P/51P.I_CCE] and, the binary output
“B09.BO_03” will be blocked. It is always adopted to
cooperate with the overcurrent protection if the circuit breaker has no enough breaking capacity to
cut off the heavy fault current, and the binary output
“B09.BO_03” must be configured as tripping
output of the overcurrent protection through the PCS-Explorer. It can prevent the circuit breaker
from being burned if the fault current is greater than the rated breaking current.
3.3.7 Overcurrent Protection Settings
All the settings of the overcurrent protection are listed in following table. For the in formation about
the common explanation of the settings, see Section 7.3 .
No. Menu text Explanation Range Step
1 50/51P.U2_VCE
The voltage s etting of the negative sequence
voltage blocking element (phase voltage)
2~70V 0.001V
2 50/51P.Upp_VCE
The voltage setting of the low voltage blocking
element (phase-to-phase voltage)
2~120V 0.001V
3 50/51P.En_VCE_CrossCtrl
The logic setting of the e xternal voltage control
function
0~1 1
4 50/51P.RCA
The relay characteristic angle for the directional
overcurrent protection
-180°~179° 1°
5 50/51P.En_VTS_Blk
The logic setting of the function which can block
the OC protection related voltage measurement
when the voltage transformer is failed
0~1 1