ABB REL650 series, Applications Manual

Page: 253 / 516

Operate
Angle1(2 ) = 180
o
Power1(2)
P
Q
IEC06000557-2-en.vsd
IEC06000557 V2 EN
Figure 120: 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 TD S
Old Calculated
= ⋅ + −
( )
⋅
1
EQUATION1893-ANSI V1 EN
(Equation 152)
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
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.
1MRK 506 334-UUS A
Section 7
Current protection
247
Application manual