3
Operation
Theory
PCS-978 Transformer Relay
3-66
Date: 2013-01-16
3.5.3 Protection Principle
3.5.3.1 Overview
Winding differential protection is based on Kirchhoff's first law and calculates differential currents
of electrical connection circuits including phase A, phase B phase C and residual differential
currents. Normally, winding differential protection is applied in following two situations.
LV
side
HV side
MV side
Magnitude
compensation
I
'_CW
Magnitude
compensation
Winding
differential
protection
Magnitude
compensation
I
'_H
I
'_M
CW side
*
*
*
*
*
*
*
*
*
I_CW
I_H
I_M
Figure 3.5-1 Winding differential protection applied to auto-transformer
HV side
LV side
Magnitude
compensation
Winding
differential
protection
I
'
_HBush
Magnitude
compensation
Magnitude
compensation
HV side 1
HV side 2
I
'
_H1
I
'
_H2
*
*
*
*
*
*
*
*
*
I_H1
I_H1
I_Bush
Figure 3.5-2 Winding differential protection used as stub differential protection
In above figures:
I_H, I_H1, I_H2 and I_M are primary values of current of each side of transformer respectively.
I_CW is primary value of common winding three-phase CT
I_HBush is primary value of current of HV side bushing CT
Summary of Contents for PCS-978
Page 1: ...PCS 978 Transformer Relay Instruction Manual NR Electric Co Ltd ...
Page 2: ......
Page 6: ...Preface PCS 978 Transformer Relay IV Date 2013 01 16 ...
Page 10: ...Preface PCS 978 Transformer Relay VIII Date 2013 01 16 ...
Page 62: ...3 Operation Theory PCS 978 Transformer Relay 3 p Date 2013 01 16 ...
Page 250: ...4 Supervision PCS 978 Transformer Relay 4 b Date 2013 01 16 ...
Page 264: ...4 Supervision PCS 978 Transformer Relay 4 14 Date 2013 01 16 ...
Page 266: ...5 Management PCS 978 Transformer Relay 5 b Date 2013 01 16 ...
Page 272: ...5 Management PCS 978 Transformer Relay 5 6 Date 2013 01 16 ...
Page 334: ...6 Hardware Description PCS 978 Transformer Relay 6 60 Date 2013 01 16 ...
Page 370: ...8 Human Machine Interface PCS 978 Transformer Relay 8 d Date 2013 01 16 ...
Page 404: ...8 Human Machine Interface PCS 978 Transformer Relay 8 34 Date 2013 01 16 ...
Page 406: ...9 Configurable Function PCS 978 Transformer Relay 9 b Date 2013 01 16 ...
Page 446: ...10 Communication PCS 978 Transformer Relay 10 26 Date 2013 01 16 ...
Page 448: ...11 Installation PCS 978 Transformer Relay 11 b Date 2012 10 09 ...
Page 456: ...11 Installation PCS 978 Transformer Relay 11 8 Date 2012 10 09 ...
Page 458: ...12 Commissioning PCS 978 Transformer Relay 12 b Date 2012 12 07 ...
Page 468: ...12 Commissioning PCS 978 Transformer Relay 12 10 Date 2012 12 07 ...
Page 470: ...13 Maintenance PCS 978 Transformer Relay 13 b Date 2012 10 09 ...
Page 474: ...13 Maintenance PCS 978 Transformer Relay 13 4 Date 2012 10 09 ...
Page 476: ...14 Decommissioning and Disposal PCS 978 Transformer Relay 14 b Date 2012 10 09 ...
Page 478: ...14 Decommissioning and Disposal PCS 978 Transformer Relay 14 2 Date 2012 10 09 ...
Page 480: ...15 Manual Version History PCS 978 Transformer Relay 15 2 Date 2013 01 16 ...