Basler Electric DGC-2020 - Manual (Page 192)

addition, if machines do not appear to share kvar equally when voltage trim is enabled, setting a nonzero
dead band will likely result in improved kvar sharing. The Voltage Trim Dead Band is in units of Percent.
The voltage trim setpoint G defines the source for voltage trim. Selections are Rated Voltage and Trim
Voltage Setting.
The remote trim bias setting H selects an analog input to use as a bias to the voltage trim set point. The
remote trim bias (%) setting I specifies the range, in percent, of the active voltage trim set point over which
the voltage trim can be biased.
The trim voltage setting J defines the voltage trim value in volts. The Alternate Voltage 1 through Alternate
Voltage 4 settings K define the voltage trim value when the corresponding Alternate Voltage Override logic
element is true in BESTlogicPlus programmable logic.
PID Controller
The PID controller controls the voltage bias from the LSM-2020 to the voltage regulator. The controller
adjusts the bias output to drive the error between desired generator voltage and measured generator
voltage to zero. Settings are provided for proportional gain
L , integral gain M , derivative gain N , derivative filter
constant O , and loop gain P of the PID controller.
var/PF Control
The var/PF controller is used to implement var and Power Factor control of the generator when it is
paralleled to the utility as indicated by the Parallel to Mains logic element in BESTlogicPlus. If var/PF
control is enabled, the generator breaker is closed, the generator is stable, and the bias control output
type is set to analog (requires LSM-2020) the var/PF controller will become active. If the Parallel to Mains
logic element is true, the var/PF controller will regulate the generator’s kvar output to achieve desired kvar
or power factor levels. When not paralleled to mains, the var/PF controller will control the kvar output to
achieve reactive power sharing between all generators in the system through Intergenset
communications. If the generator breaker is open or controller is disabled, the machine will operate iin
voltage droop.
When control Q is enabled and the control mode R is set to var, the var setpoint can be derived from either a
user setting or an analog input. The DGC-2020 calculates an operating kvar setpoint based on the kvar
setpoint source setting
S . When this is set to User Setting, the operating kvar setpoint is equal to the
configured kvar setpoint T . When the kvar setpoint source setting S is set to LSM-2020 input or an AEM-
2020 input, the operating kvar setpoint is equal to the value calculated from the analog input. Parameters
are available for kvar analog max
U and kvar analog min V .
When control mode R is set to PF, the PF setpoint can be derived either from a user setting or from an
analog input. The DGC-2020 calculates an operating PF setpoint based on the PF setpoint source
setting
W . When this is set to User Setting, the operating PF setpoint is equal to the configured PF
setpoint X . When the PF setpoint source setting W is set to LSM-2020 input or an AEM-2020 input, the
operating PF setpoint is equal to the value calculated from the analog input. Parameters are available for
PF analog max
Y and PF analog min Z .
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 var/PF bias from the LSM-2020 to the voltage regulator. The
controller adjusts the bias output to drive the error between desired generator var/PF and measured
generator var/PF to zero. Settings are provided for proportional gain
AA , integral gain BB , derivative gain CC ,
derivative filter constant DD , loop gain EE , and parallel to mains gain FF of the PID controller.
The percent voltage droop to be used when the unit is in droop mode is determined by the droop
percentage setting
GG . Voltage droop mode is entered any time the generator breaker is open. Voltage
droop is also the mode when the generator breaker is closed and var/PF control is disabled. If it is desired
to disable voltage droop, set the droop percentage to 0. The voltage droop gain setting
HH determines the
gain factor applied to the voltage 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 voltage should be compared to the desired droop. If it is not possible to load
the unit to full load, the droop test can be performed at partial load. The expected voltage is determined
by the following equation.
Expected voltage reduction in droop - (actual load/machine capacity)
∗ (droop percentage/100) ∗ rated
voltage.
If the actual voltage drop does not match the expected value, calculate the error by dividing the expected
drop by the actual drop, and putting the result in as the droop gain.
4-82 DGC-2020 BESTCOMSPlus
® Software
9400200990 Rev X