ABB REB670 Series, Applications Manual

Page: 206 / 476

Operate
Angle1(2 ) = 180
o
Power1(2)
P
Q
IEC06000557-2-en.vsd
IEC06000557 V2 EN-US
Figure 112: 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
67 .
3
N
S UBase IBase
= × ×
EQUATION1708 V1 EN-US
(Equation 67)
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:
( )
1
Old Calculated
S k S k S
= × + - ×
EQUATION1893 V1 EN-US
(Equation 68)
Where
S is a new measured value to be used for the protection function
S
old
is the measured value given from the function in previous execution cycle
S
Calculated
is the new calculated value in the present execution cycle
k is settable parameter
The value of
k=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:
Section 7 1MRK 505 370-UEN D
Current protection
200 Busbar protection REB670
Application manual