ABB Relion 670 Series Applications Manual page 202

Section 8
Current protection
=
S
N
EQUATION2047 V1 EN-US
The setting
protection function. The setting is given in degrees. For active power the set angle should be 0° or
180°. 0° should be used for generator low forward active power protection.
IEC06000556 V1 EN-US
Figure 92: 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 79.
=
S
N
EQUATION2047 V1 EN-US
The drop out power will be
The possibility to have low pass filtering of the measured power can be made as shown in the
formula:
196
× ×
3 VBase IBase
Angle1(2) gives the characteristic angle giving maximum sensitivity of the power
Q
Operate
Angle1(2) = 0
Power1(2)
× ×
3 VBase IBase
Power1(2) + Hysteresis1(2) .
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°
P
en06000556.vsd
1MRK 511 401-UUS F
(Equation 78)
(Equation 79)
Bay control REC670
Application manual