ABB REC650 Applications Manual page 150

Section 6
Current protection
144
Operate
IEC06000557 V2 EN
Figure 61: 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.
The possibility to have low pass filtering of the measured power can be made as shown in
the formula:
(
S TD S 1 TD S
= ⋅ + −
Old
EQUATION1893-ANSI V1 EN
Where
S is a new measured value to be used for the protection function
S is the measured value given from the function in previous execution cycle
old
S is the new calculated value in the present execution cycle
Calculated
TD is settable parameter
The value of TD=0.98 or even TD=0.99 is recommended in generator reverse power
applications as the trip delay is normally quite long. This filtering will improve accuracy
of the power function.
Q
Angle1(2 ) = 180
Power 1(2)
)
⋅
Calculated
1MRK 511 286-UUS A
o
P
IEC06000557-2-en.vsd
Application manual
(Equation 69)