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3 Operation Theory
PCS-978 Transformer Relay
3-65
Date: 2013-01-16
No.
Setting Item
Range
Step
Unit
Description
is zero.
5 x.64REF.En_CTS_Blk
0: disable
1: enable
1
Logic setting of enabling/disabling blocking REF
protection during CT circuit failure
6 x.64REF.En_NeuCurr
0: disable
1: enable
1
Logic setting of enabling/disabling neutral current
criterion.
7 x.64REF.En
0: disable
1: enable
1
Logic setting of enabling/disabling REF protection.
8 x.64REF.OutMap
0000~FFFF
Tripping logic setting of REF protection
3.5 Winding Differential Protection (87W/87N)
3.5.1 Application
When each side and common winding of auto-transformer are installed with three phase CTs,
winding differential protection can be equipped. Winding differential protection is based on
Kirchhoff's law, so inrush current has no effect on it. Winding differential protection consists of
phase winding differential protection and residual winding differential protection. Residual winding
differential protection adopts the calculated residual current of each side and common winding for
the protection calculation and three-phase CT polarity is easy to be checked. The operation
principle of which is similar to that of REF protection, but compared to REF protection, winding
differential protection can operate not only during internal earth faults but also during
phase-to-phase faults.
3.5.2 Function
Maximum 5 group CT inputs applied for an auto-transformer with two circuit breakers at HV
and MV sides respectively.
Maximum 3 winding differential protections for each side of a three-winding transformer
Inrush current has no effect on winding differential protection.
Winding differential protection has high sensitivity to internal earth faults because there is no
load current in the restraint current.
The tap of transformer has no effect on winding differential protection.
CT transient detection function based on the ratio of residual current to positive current is
adopted to eliminate the influence of difference of transient characteristic to winding
differential protection.
CT saturation detection function based on 2
nd
and 3
rd
harmonics is adopted to avoid
maloperation of winding differential protection during an external fault.
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 ...