5830
91
UV3
6
Undervoltage Block On
5831
91
UV3
7
Undervoltage Block Off
5888
92
UV4
0
Start ON
5889
92
UV4
1
Start OFF
5890
92
UV4
2
Trip ON
5891
92
UV4
3
Trip OFF
5892
92
UV4
4
Block ON
5893
92
UV4
5
Block OFF
5894
92
UV4
6
Undervoltage Block On
5895
92
UV4
7
Undervoltage Block Off
In the register of the UV function is recorded start, trip or blocked “On” event process data. In the table
below is presented the structure of UV function register content. This information is available in 12 last
recorded events for all provided instances separately.
Table. 5.4.12. - 123. Register content
Date & Time
Event
code
Fault
type
Pretrig
voltage
Fault
voltage
Prefault
voltage
Trip time
remaining
Used
SG
dd.mm.yyyy
hh:mm:ss.mss
5696-5895
Descr.
A…A-
B-C
Start average
voltage
Trip -20ms
averages
Start -200ms
averages
0ms - 1800s
1 - 8
5.4.13. Neutral voltage U0> (59N)
Neutral overvoltage function (NOV) is used for non-directional instant- and time delayed earth fault
protection for various applications including feeder, lter and machine applications of utilities and
industry. Each IED with voltage protection module has four available instances of the function (U0>,
U0>>, U0>>>, U0>>>>).
NOV -function measures constantly phase to ground voltage magnitudes and calculates the zero
sequence component. Neutral overvoltage protection is scaled to line- to line fundamental frequency
component level. In case line to line voltage of system is 100 V secondary the earth fault is 100% of Un
when calculated zero sequence voltage reaches 100/
√
3 V = 57.74 V.
Below is presented the formula for symmetric component calculation and therefore to zero sequence
voltage calculation.
See zero sequence calculation examples below.
Figure. 5.4.13. - 77. Normal situation
AQ-F255
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
134