Supervision of voltage in negative-sequence (V2 error)
9.2.16
Applying the voltage in negative-sequence is calculated regularly using three-phase voltages
measured in the IED. If Equation (9.2-2) is satisfied over 10 seconds, the supervision function
determines that a failure occurs in the input circuit.
The voltage in negative sequence can be used to detect a failure within the voltage input
circuit in high sensitivity. It facilitates the detection of the incorrect phase sequence if cables
are connected irregularly.
1.
where,
a = Phase shift operator of 120
Error level
(i)
The default error level is set at level 3 (Minor error), but the user can program the level using
setting [CHK_V2:LVl]; then, set On for the setting [CHK_V2:Sw]. The time for the detection
can be set using [CHK_V2:Timer], which is set for 15 seconds as default. After the error is
cleared, it is reset in the time that is the same as the setting time to the detection.
Error message
(ii)
When detecting an error, an error message can be shown on the LCD screen and an LED is lit.
Table 9.2-32 Error messages provided by the supervisor in CHK_V2_CBP
Message and level
V2 error
Error level
Table 9.2-33 Detailed information in Hexadecimal in CHK_V2_CBP
Display
area
10000000:
01000000:
00100000:
Top row
00010000:
00001000:
00000100:
Middle row
Bottom row
2
| V
+
V
+ aV
a
b
3
Meaning of the information
Detection of the negative-sequence voltage
Meaning of the detailed information
Left column
ZoneA
ZoneB
ZoneC
ZoneD
ZoneE
ZoneF
(No information displayed)
(No information displayed)
- 484 -
|
c
≥ 6.35 (V)
Minor error (Level 3)
Right column
00000001: ORed state in all zones
(No information displayed)
(No information displayed)
6F2S1931 (0.20)
(9.2-2)
Centralized GRB200
(Soft: 030, 031, 032, 033, 034)