Arcteq Generator Commander, Instruction Manual

Page: 442 / 561

Figure. 6.2.1.4.1 - 219. UEL2 transfer function.
UEL characteristic curve f(x) is compiled by setting coordinates either in an admittance graph (with P/
U
2
and Q/U
2
as the axes) or in a current graph (with P/U and Q/U as the axes). The limitation value
between the given coordinates is calculated through linear interpolation. When active power P is
exceeds 1.0 p.u., the limitation value is calculated through linear extrapolation using the coordinates
given for 0.8 p.u. and 1.0 p.u.
Table. 6.2.1.4.1 - 361. UEL setting parameters.
Name Range Step Default Comments
Underexcitation
limiter (UEL)
status
0: Enabled
1: Blocked
2: Limiter active
- - Displays the status of the underexcitation limiter.
UEL output
now
-500.00…500.00p.u./p.u. 0.01p.u./p.u. 0.00p.u./p.u. Defines the output of the UEL at the moment.
Underexcitation
limiter
0: Disabled
1: Enabled
- 1: Enabled Enables and disables the UEL.
Proportional
gain KpUEL
0.000…20.000p.u./p.u.
0.001p.u/
p.u.
1.000p.u/
p.u.
Defines the proportional gain for the UEL.
UEL inverse
time delay (0 =
instant)
0.000…10.000 1/s 0.001 1/s 0.000 1/s
Defines the inverse time delay for the UEL.
Therefore, the bigger the set value, the faster the
limiter takes effect.
Underexcitation
limiter type
0: Admittance diagram
1: Current diagram
-
0:
Admittance
diagram
Defines the limitation principle.
When the option "Current diagram" is selected,
the limit values are calculated from the measured
values without the curve shifts by the machine
voltage.
When the option "Admittance diagram" is
selected, limit values are calculated from the
admittance values, with the curve shifts (1/U2)
by machine voltage. The higher the voltage, the
further the curve shifts from the Q axis, and vice
versa. This is the recommended option.
Q-axis
coordinate at
P=0.00 p.u.
-1.00...1.00 0.01 -0.30
These parameters define the limits of the reactive
power and the points at which the
underexcitation limiter begins to increase the
excitation. (P = active power.)
Q-axis
coordinate at
P=0.20 p.u.
-1.00...1.00 0.01 -0.25
Genera Generattor Commander or Commander
Instruction manual
Version: 2.07
440 © Arcteq Relays Ltd
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