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3 Operation Theory
PCS-978 Transformer Relay
3-159
Date: 2013-01-16
ln
is natural logarithm.
B
I
is the base current , i.e. [x.49.Ib_Set].
k
is thermal overload coefficient, i.e. [x.49.K_Alm] or [x.49.K_Trp].
The hot time-current limit characteristic is adopted in the protection relay. The calculation is carried
out at zero of Ip, so users need not to set the value of Ip.
Tripping outputs of the protection is controlled by current, even if the thermal accumulation value is
greater than the setting for tripping, the protection drops off instantaneously when current
disappears. Alarm outputs of the protection is not controlled by current, and only if the thermal
accumulation value is greater than the setting for alarm, alarm output contacts, which can be
connected to block the auto-recloser of a circuit breaker, will operate.
3.18.4 Logic
Timer
t
t
EN
[x.49.En_Alm]
SIG
[x.49.En1]
SIG
[x.49.En2]
SIG
[x.49.Blk]
&
SIG
[x.49.I3P]
SET
[x.49.Ib_Set]
&
Timer
t
t
[x.49.St]
[x.49.Alm]
[x.49.Op]
Figure 3.18-2 Logic diagram of thermal overload protection of x side
For thermal overload protection, if following three conditions are met, the stage protection will be
enabled.
(1) Logic setting [x.
49.En] is set to “1”.
(2) Enabling inputs [x.49.En1],[ x.
49. En2] are both set to “1”.
(3) Blocking input [x.
49.Blk] is set to “0”.
When the protective function block is disabled, [x.49.St], [x.49.Alm] and [x.49.Op] signals are both
reset. Default values of Inputs [x.49.En1] and [x.
49.En2] are “1” and [x.49.Blk] is “0” when those
inputs are not connected to external signals or settings.
Содержание PCS-978
Страница 1: ...PCS 978 Transformer Relay Instruction Manual NR Electric Co Ltd ...
Страница 2: ......
Страница 6: ...Preface PCS 978 Transformer Relay IV Date 2013 01 16 ...
Страница 10: ...Preface PCS 978 Transformer Relay VIII Date 2013 01 16 ...
Страница 62: ...3 Operation Theory PCS 978 Transformer Relay 3 p Date 2013 01 16 ...
Страница 250: ...4 Supervision PCS 978 Transformer Relay 4 b Date 2013 01 16 ...
Страница 264: ...4 Supervision PCS 978 Transformer Relay 4 14 Date 2013 01 16 ...
Страница 266: ...5 Management PCS 978 Transformer Relay 5 b Date 2013 01 16 ...
Страница 272: ...5 Management PCS 978 Transformer Relay 5 6 Date 2013 01 16 ...
Страница 334: ...6 Hardware Description PCS 978 Transformer Relay 6 60 Date 2013 01 16 ...
Страница 370: ...8 Human Machine Interface PCS 978 Transformer Relay 8 d Date 2013 01 16 ...
Страница 404: ...8 Human Machine Interface PCS 978 Transformer Relay 8 34 Date 2013 01 16 ...
Страница 406: ...9 Configurable Function PCS 978 Transformer Relay 9 b Date 2013 01 16 ...
Страница 446: ...10 Communication PCS 978 Transformer Relay 10 26 Date 2013 01 16 ...
Страница 448: ...11 Installation PCS 978 Transformer Relay 11 b Date 2012 10 09 ...
Страница 456: ...11 Installation PCS 978 Transformer Relay 11 8 Date 2012 10 09 ...
Страница 458: ...12 Commissioning PCS 978 Transformer Relay 12 b Date 2012 12 07 ...
Страница 468: ...12 Commissioning PCS 978 Transformer Relay 12 10 Date 2012 12 07 ...
Страница 470: ...13 Maintenance PCS 978 Transformer Relay 13 b Date 2012 10 09 ...
Страница 474: ...13 Maintenance PCS 978 Transformer Relay 13 4 Date 2012 10 09 ...
Страница 476: ...14 Decommissioning and Disposal PCS 978 Transformer Relay 14 b Date 2012 10 09 ...
Страница 478: ...14 Decommissioning and Disposal PCS 978 Transformer Relay 14 2 Date 2012 10 09 ...
Страница 480: ...15 Manual Version History PCS 978 Transformer Relay 15 2 Date 2013 01 16 ...