3 Operation Theory
PCS-978 Transformer Relay
3-129
Date: 2013-01-16
[x.50/51G4.Opt_Curve] to
“13” to customize the inverse-time curve characteristic, and
constants
K
,
and
C
with PCS-Explorer software.
Define-time or inverse-time phase overcurrent protection drops off instantaneously.
3.13.3.4 Residual Direction Element
Calculated residual voltage (3U0) is adopted as polarizing quantity (i.e. polarizing voltage) of
residual directional element. When the neutral current (IN) is selected for the calculation of ground
overcurrent, it is the operating quantity (i.e. fault current), and when calculated residual current
(3I0) is selected, it is the operating quantity.
When a fault occurs at forward direction, the angle polarizing voltage
ref
U
leading fault current
dir
I
is:
I
U
dir
ref
k
arg
Equation 3.13-3
When a fault occurs at reverse direction, the angle
is:
Relay characteristic angle
sen
(setting [x.50/51G.RCA]), i.e. the angle polarizing voltage leading
fault current, is given as the directional setting, and the forward operating range is:
90
90
arg
sen
dir
ref
sen
I
U
Equation 3.13-5
If VT and CT are connected as
shown, i.e. polarity of CT is at busbar side, and
forward direction is to protected object, then forward and reverse operating regions are shown in
following
Forward
Reverse
VT
CT
Direction
Element
Dir
Protected
Object
Figure 3.13-2 Connection of VT and CT of directional element
k
dir
ref
k
I
U
180
arg
Equation 3.13-4
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 ...