ABB REC670 Applications Manual page 225

1MRK 511 401-UUS A
Bay control REC670 2.2 ANSI
Application manual
Operate
Angle1(2) = 0
Power1(2)
IEC06000556 V1 EN-US
Figure 88: 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 74.
= × ×
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 = ⋅ + 1 − TD S ⋅
Old Calculated
EQUATION1893-ANSI V1 EN-US
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
Q
°
en06000556.vsd
Section 8
Current protection
P
(Equation 74)
(Equation 75)
219