3 Operation Theory
PCS-978 Transformer Relay
3-29
Date: 2013-01-16
picks up.
Flg_CTS is the internal flag indicating CT circuit failure is distinguished.
Flg_Inrush_DPFC_Diff is the internal flag indicating inrush current is distinguished for DPFC
differential protection.
Flg_OvExc_Hm3/Hm5 is the internal flag indicating overexcitation of power transformer is
distinguished by the third or fifth harmonic criterion
3.2.4.3 Logic of CT Circuit Failure
SIG
U2>2%Upp
SIG
Flg_DPFCVolt
SIG
Flg_CurrIncrease
SIG
Ipmax>1.1pu
SIG
FD_BiasDiff
&
&
T 0ms
SIG
Flg_CTS
SIG
I2>0.04Ipmax or I2>0.1In
&
&
≥
1
≥
1
Flg_CTS
[x.AlmH_CTS]
[87T.Alm_CTS]
Figure 3.2-10 Logic diagram of CT circuit failure
Where:
FD_BiasDiff is the signal indicating that the fault detector of biased differential protection picks up.
Upp is the secondary phase-to-phase rated voltage
.
Flg_DPFCVolt is the internal flag indicating that
DPFC element of any phase-to-phase voltage of any
side picks up
Flg_CurrIncrease is the internal flag indicating that any phase current of any side increases after
fault detector picks up.
Ipmax>1.1pu represents that the maximum phase current is greater than 1.1pu after the fault
detector picks up.
Flg_CTS is the internal flag indicating that CT circuit failure is distinguished.
[x.AlmH_CTS] is the alarm signal of CT circuit failure of x side of transformer.
[87T.Alm_CTS] is the alarm signal of CT circuit failure for current differential protection. If CT
circuit failure for REF protection or winding differential protection is detected, the corresponding
signal [64REF.Alm_CTS] or [87W.Alm_CTS] will be issued.
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 ...