Basler Electric DGC-2020 - Manual (Page 336)

In short, when the generator breaker is open, the kW controller is disabled. When the generator breaker is
closed and the unit is not paralleled to the utility, the kW controller’s set point is derived from the load
share line. When the generator breaker is closed and the machine is paralleled to the utility, the kW
controller uses the Base Load Level (%) setting as its set point. Generator breaker status is
communicated to the DGC-2020 through the status input on the generator breaker block in
BESTlogicPlus Programmable Logic.
Settings are provided to allow a generator to ramp up its kW generation to minimize system disruption
when it transitions onto a system that is load sharing. A similar ramp down transition is also implemented
when the generator is brought off line.
Each load share module has a set of internal contacts that physically disconnects it from the load share
line circuit when the generator is off line. These contacts are open whenever the unit’s generator breaker
is open.
kvar Control Overview and Theory of Operation in the DGC-2020
The DGC-2020 and LSM-2020 can provide system kvar control. When the generator breaker is open, the
unit operates in voltage droop mode. When the generator breaker is closed and the generator is part of
an island system (the system is not paralleled to the utility), the unit shares kvar with the other machines
in the system through intergenset communications. When the generator is paralleled to the utility, the kvar
controller is enabled; either power factor or kvar control is implemented according to the VAR/PF control
mode setting. Generator breaker status is communicated to the DGC-2020 through the status input on the
generator breaker block in BESTlogicPlus Programmable Logic.
When var control mode is selected and the generator is paralleled to the utility, the kvar controller’s set
point is equal to the kvar Setpoint (%) setting. The setting is in units of percentage of the machine’s rated
kvar, which is calculated from the rated kW and rated Power Factor.
When power factor control mode is selected and the generator is paralleled to the utility, the var
controller’s set point is calculated as the percentage of rated kvar, which will maintain the power factor of
the machine at the PF Setpoint setting. The Parallel to Mains (ParToMains) logic element in
BESTlogicPlus Programmable Logic is used to indicate to the DGC-2020 that it is paralleled to the utility.
Setup of the DGC-2020 and the LSM-2020 for Load Sharing and/or kW Control
The setup of a load sharing and kW control system requires several steps:
1. Wire the DGC-2020, LSM-2020, and any external devices that interact with the DGC-2020 or the
LSM-2020.
2. Set all DGC-2020 settings related to Initial Machine Setup.
3. Configure DGC-2020 breaker control.
4. Configure the synchronizer function (if used).
5. Configure the parameters related to load sharing and kW control:
a. Enable the load share module
b. Configure the load share line voltage range
c. Configure the AVR bias output voltage or current range and polarity
d. Configure the governor bias output voltage or current range and polarity
e. Configure the kW and speed control parameters
f. Change the voltage and kvar control parameters
g. Configure demand start/stop related parameters (if demand start/stop is used)
i. Configure demand start/stop parameters
ii. Configure generator sequencing parameters
iii. Configure the generator network parameters
iv. Configure the LSM-2020 Ethernet parameters
h. Tune the kW, kvar, speed, and voltage controllers
Setup of some of these parameters are already covered in other sections of the DGC-2020 instruction
manual; you will be directed to appropriate sections of this manual when this is the case. Detailed setup
procedures are presented for those that are not addressed elsewhere.
7-48 DGC-2020 Setup 9400200990 Rev X