
3 Operation Theory
PCS-978 Transformer Relay
3-127
Date: 2013-01-16
Direction
Element
3I0 from I3P
or IN from I1P
3U0 from I3P
Harmonic
Blocking
Element
St
Op
Direction signal
Hm blocking signal
[Alm_VTS]
St
Op
St
Op
St
Op
Ground
Overcurrent
Element
Ground
Overcurrent
Element
Ground
Overcurrent
Element
Ground
Overcurrent
Element
Stage1
Stage2
Stage3
Stage4
Figure 3.13-1 Function diagram of ground overcurrent protection
3.13.3.2 Operation Criterion
The operation criterion of each stage ground overcurrent protection is:
0
3
I
>[x.50/51Gn.3I0_Set]
Equation 3.13-1
Where:
0
3
I
is measured neutral current or calculated residual current, which is selected by user through
the setting [x.50/51Gn.Opt_3I0], n (n=1, 2 or 3) or [x.50/51G4.Opt_3I0].
[x.50/51Gn.3I0_Set] is the current setting of stage n (n=1, 2 or 3) of ground overcurrent protection
of x side.
If ground current is greater than the setting of any stage enabled ground overcurrent protection,
the stage ground overcurrent protection will operate after time delay if directional element operates
(or directional element not enabled) and no harmonic detected (or harmonic blocking not enabled),
and the stage protection will drop off instantaneously after fault current disappears.
3.13.3.3 Time Curve
Ground overcurrent protection stage 1, stage 2 and stage 3 are definite-time characteristic and
each stage can perform instantaneous operation with the corresponding time delay setting at zero.
Stage 4 can be selected as definite-time or inverse-time characteristic, and inverse-time operating
time curve is as follows.
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 ...