Manual 37143A
MFR 15 - Protection Relay & Control
Page 56/119
© Woodward
Droop
Volt. controller
Droop 00.0%
Controller droop characteristic curve
00.0 to 20.0 %
If this control is to be operated on a generator in parallel with other generators and
voltage control is enabled, a droop characteristic curve must be used. Each genera-
tor in the system will require the same value to be configured for the droop charac-
teristic, so that when the system is stable the reactive power will be distributed pro-
portionally among all generators in relation to their rated power.
Example
Rated power:
500 kW
Rated voltage set point:
400 V
Droop: 5.0
%
Reactive power
0 kvar = 0% of rated reactive power
Voltage is adjusted to (400 V – [5.0% * 0.0]) = 400 V.
Reactive power
+250 kvar (ind) = +50 % of rated reactive power
Voltage is adjusted to (400 V – [5.0% * 0.50]) = 390 V.
Reactive power
+500 kvar (ind) = +100 % of rated reactive power
Voltage is adjusted to (400 V – [5.0% * 1.00]) = 380 V.
Power-Factor Controller (
Option C
)
NOTE
It is vital to ensure that the following variables are properly configured for the controller to operate
properly
•
Rated power
•
Primary current
•
Primary voltage
If these variables are not configured properly, the droop controller and/or power factor controller may
not operate properly.
Power-factor-
controller ON
Power factor controller
ON/OFF
ON
................In a mains parallel operation automatic control of the power factor is
enabled. If there are excessively low currents (secondary current less
than 5 % of I
rated
) the power factor cannot be accurately measured. In
order to prevent power swings, the controller automatically locks the
power factor at a set value. The subsequent screens of this function
are displayed.
OFF
..............Power factor control is disabled. The subsequent screens of this func-
tion are not displayed.
Pow.fact. contr.
Setp. variable
(with
Option G
/
GU
only)
Presetting power factor set point selection
variable/fixed
Fixed
.............The set fixed set point value is continually adjusted. An external cor-
rection of the set point value via actuating signals "higher" or "lower"
is not possible.
Variable
.......The set point can be externally corrected within certain limits.