Winco DGC-2020 - Manual (Page 128)

4-58 DGC-2020 BESTCOMSPlus Software 9400200990 Rev K
P PF Setpoint Source: User Setting, LSM Analog Input 1, or Analog Inputs 1-8.
Q PF Setpoint: Adjustable from –0.60 to 0.60 in increments of 0.01.
R PF Analog Max: Adjustable from –0.60 to 0.60 in increments of 0.01.
S PF Analog Min: Adjustable from –0.60 to 0.60 in increments of 0.01.
T Proportional Gain (Kp): Adjustable from 0 to 1,000 in increments of 0.001.
U Integral Gain (Ki): Adjustable from 0 to 1,000 in increments of 0.001.
V Derivative Gain (Kd): Adjustable from 0 to 1,000 in increments of 0.001.
W Derivative Filter Constant (Td): Adjustable from 0 to 1 in increments of 0.001.
X Loop Gain (Kg): Adjustable from 0 to 1,000 in increments of 0.001.
Y Droop Percentage: Adjustable from 0 to 10 percent in 0.001 % increments.
Z Voltage Droop Gain: Adjustable from 0 to 1,000 in increments of 0.001.
AA Ramp Rate: Adjustable from 0 to 100 percent/second in 0.1 %/s increments.
Governor Bias Control Settings
The bias control output type
A should be set to contact when operating without an optional LSM-2020.
The DGC-2020 adjusts the generator voltage and frequency by issuing speed correction signals to the
generator governor. Correction signals are issued in the form of DGC-2020 output contact closures.
These correction signals can be either continuous or proportional
B . Proportional correction uses control
pulses of varying widths C and intervals D . Initially, long pulses are issued when the voltage and frequency
differences are large. As the correction pulses take effect and the voltage and frequency differences
become smaller, the correction pulse widths are proportionally decreased. Proportional correction pulses
are beneficial in applications where fixed correction pulses can result in overshooting the slip frequency
and regulation offset targets.
When an optional LSM-2020 is connected, the bias control output type
A should be set to analog. This
enables a PID controller that controls the bias signal from the LSM-2020 to the speed governor. The
controller adjusts the bias output to drive the error between desired generator speed and measured
generator speed to zero. Settings are provided for proportional gain
E , integral gain F , derivative gain G ,
derivative filter constant H , and loop gain I of the PID controller.
The speed trim enable setting J sets speed trimming to the speed trim setpoint K when the generator
breaker is closed and the machine is not paralleled to the utility. If speed trimming is enabled in all
generators in an islanded system, it is ensured that the system will run at the speed trim setpoint. If it is
not enabled in any units, the islanded system may deviate from the speed trim setpoint, depending on the
initial speed settings of the isochronous governors. Speed trim should be enabled in all units or disabled
in all units of an islanded system. If it is enabled in only a subset of the units, speed trimming and load
sharing may conflict, resulting in unpredictable load sharing and system frequency.
BESTCOMSPlus governor bias control settings (DGC-2020, Bias Control Settings, Governor Bias Control
Settings) are illustrated in Figure 4-53.
kW Control - Real Power Control Settings
When enabled
L , the DGC-2020, used in conjunction with an optional LSM-2020, can accomplish kW
sharing between similarly equipped generators. kW control is disabled when an optional LSM-2020 is not
connected.
kW control is accomplished with a PID controller that controls the speed bias signal from the LSM-2020 to
the speed governor. The controller adjusts the bias output to drive the error between desired kW
generation and measured kW generation to zero.
Settings are provided for proportional gain
M , integral gain N , derivative gain O , derivative filter constant P ,
and loop gain Q of the PID controller.
The percent speed droop to be used when the unit is in droop mode is determined by the droop
percentage setting
R . Speed droop mode is entered any time the generator breaker is open. Speed droop
is also the mode when the generator breaker is closed if kW load sharing is disabled. If it is desired to
disable speed droop, set the droop percentage to 0. The speed droop gain setting
S determines the gain
factor applied to the speed droop percentage to compensate for governor differences and achieve
desired droop performance. In order to test the operation of droop, the unit must be loaded to full load
and the resulting generator speed should be compared to the desired droop. If it is not possible to load
the unit to full load, the droop test may be performed at partial load. The expected speed is determined by
the following equation.