Basler Electric DGC-2020 - Manual (Page 335)

line voltages contributed by each unit. This average voltage is proportional to the average percentage
load of the machines.
The goal of a load sharing system is for all machines to share equally on a percentage of capacity basis.
To accomplish this, each machine contains a load controller or kW controller, which provides regulation of
the machine’s kW output. The setting for each kW controller is derived from the system load share line
voltage. The load share line voltage is measured, scaled, and fed back to the machine’s kW controller.
Thus, the setting for the kW controller is the average percentage load of the system. Thus, each
machine’s kW controller is driving the machine’s kW output to a level equal to the average percentage kW
load of the system. The result in a properly tuned system is that all machines share kW equally on a
percentage of capacity basis.
While some newer systems replace the load share line using communication between the generators
(inter-genset communications) many existing load share implementations use an analog load share line.
Figure 7-54 shows a diagram of an analog load share line as presented in this document.
Figure 7-54. Load Share Line Implementation on a System of N Machines
If a unit or set of units is paralleled to the utility, they derive their kW control setting from the Base Load
Level (%) setting, and disregard the load share line input. The Parallel to Mains (ParToMains) logic
element in BESTlogicPlus Programmable Logic is used to indicate to the DGC-2020 that is it paralleled to
the utility.
R R
% KW Load
Unit 1
Load Share
Line Feedback To KW
Controller
Load Share
Line Output
Voltage Proportional
to % KW Load Unit N
Load Share Line junction voltage is
proportional to system % KW load.
R
Unit 2
R
Unit N-1
P0059-37
9400200990 Rev X DGC-2020 Setup 7-47