Event block name
Event names
VUB4
Trip OFF
VUB4
Block ON
VUB4
Block OFF
The function registers its operation into the last twelve (12) time-stamped registers; this information is
available for all provided instances separately. The register of the function records the ON event
process data for START, TRIP or BLOCKED. The table below presents the structure of the function's
register content.
Table. 5.3.13 - 134. Register content.
Date and time
Event
Pre-trigger
voltage
Fault
voltage
Pre-fault
voltage
Trip time
remaining
Used SG
dd.mm.yyyy
hh:mm:ss.mss
Event
name
Start/Trip -20ms
voltage
Start/Trip
voltage
Start -200ms
voltage
0 ms...1800s
Setting group 1...8
active
5.3.14 Overfrequency and underfrequency protection (f>/<; 81O/81U)
The frequency protection function can be used both in overfrequency and in underfrequency situations,
and it has four (4) stages for both. Frequency protection can be applied to protect feeder, bus,
transformer, motor and generator applications. The difference between the generated power and the
load demand can cause the frequency to drop below or rise above the allowed level. When the
consumption is larger than the generated power, the frequency may drop. When more power is
generated than is consumed, overfrequency can occur.
In generator applications too big a load or a malfunction in the power controller can cause the
frequency to decrease. Underfrequency causes damage to turbine wings through vibration as well
as heating due to increased iron losses, dropped cooling efficieny and over-magnetization in step-up
transformers. Overfrequency protection prevents the generator from running too fast which can cause
damage to the generator turbine.
Underfrequency and overfrequency protection can be used as an indicator of an accidental island
operation in distributed generation and in some consumers (as it is unlikely that the consumed and
generated power are the same). Overfrequency is also often used to control power generation to keep
the system's frequency consistent.
Each stage can be activated and deactivated individually. After the f>/< mode has been activated
(
Protection
→
Stage activation
→
Frequency stages), the user can activate and deactivate the
individual stages at will (
Protection
→
Frequency
→
Frequency protection f >/<
→
INFO
→
Stage
operational setup).
The frequency protection function uses a total of eight (8) separate setting groups which can be
selected from one common source.
The function can operate on instant or time-delayed mode.
The operational logic consists of the following:
• input magnitude processing
• threshold comparator
• block signal check
• time delay characteristics
• output processing.
The inputs for the function are the following:
A
AQ
Q-M255
-M255
Instruction manual
Version: 2.06
160
© Arcteq Relays Ltd
IM00020
Содержание AQ-M255
Страница 1: ...AQ M255 Motor protection IED Instruction manual...
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Страница 384: ...Figure 7 4 189 Example block scheme A AQ Q M255 M255 Instruction manual Version 2 06 382 Arcteq Relays Ltd IM00020...
Страница 405: ...Figure 8 14 211 Device installation A AQ Q M255 M255 Instruction manual Version 2 06 Arcteq Relays Ltd IM00020 403...