ABB Relion 670 Series Applications Manual page 216

Section 7
Current protection
Operate
IEC06000557 V2 EN-US
Figure 114: For reverse power the set angle should be 180° in the overpower function
TripDelay1(2) is set in seconds to give the time delay for trip of the stage after pick up.
Hysteresis1(2) is given in p.u. of generator rated power according to equation 70.
=
S 3 VBase IBase
N
EQUATION2047 V1 EN-US
The drop out power will be Power1(2) - Hysteresis1(2).
The possibility to have low pass filtering of the measured power can be made as shown in the formula:
S TD S
=
EQUATION1893-ANSI V1 EN-US
Where
S
S
old
S
Calculated
TD
The value of TD=0.92 is recommended in generator applications as the trip delay is normally quite long.
The calibration factors for current and voltage measurement errors are set % of rated current/voltage:
210
Power 1(2)
× ×
( )
1 TD S
⋅ + − ⋅
Old Calculated
is a new measured value to be used for the protection function
is the measured value given from the function in previous execution cycle
is the new calculated value in the present execution cycle
is settable parameter
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Q
o
Angle1(2 ) = 180
IEC06000557-2-en.vsd
1MRK 505 370-UUS Rev. K
P
(Equation 70)
(Equation 71)
Busbar protection REB670
Application manual