ABB REB670 Series, Applications Manual

Page: 201 / 476

Operate
Angle1(2) = 0
°
Power1(2)
P
Q
en06000556.vsd
IEC06000556 V1 EN-US
Figure 109: For low forward power the set angle should be 0° in the underpower 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
54 .
3
N
S UBase IBase
= × ×
EQUATION1708 V1 EN-US
(Equation 54)
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 55)
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:
IAmpComp5, IAmpComp30, IAmpComp100
1MRK 505 370-UEN D Section 7
Current protection
Busbar protection REB670 195
Application manual