If the measured voltage is higher than the voltage from the internal power transducer, the controller increases its load to
match the voltage on the load sharing line.
If the measured voltage is lower than the voltage from the internal power transducer, the controller decreases its load to
match the voltage on the load sharing line.
The voltage on the load sharing line only differs from the voltage from the internal power transducer, if two or more controllers are
connected to the load share line.
When the hardware is installed, the analogue load share line is active. That it, it is active both when one generator is running in a
single application, and when a number of generators are actually sharing the load. For generator running alone, disabling the load
share line is recommended to keep the frequency regulator active.
INFO
To disable the load sharing line, use M-Logic Output, Inhibits, Inh. analogue load share.
To improve the handling of several generators in the same application, analogue load sharing works as backup system for power
management option G5. This means that if both analogue load sharing and power management are available in the same controller,
load sharing is done by the CAN bus communication as the primary choice. If a CAN bus error occurs, load sharing continues on the
analogue load sharing line. The generators stay stable even though the power management is lost.
Example 1: Load adjustment
Two generators are running in parallel. The loads of the generators are:
Generator
Actual load Voltage on load sharing line
Generator 1 100 % 4 V DC
Generator 2 0 % 0 V DC
The voltage level on the load sharing line can be calculated to:
U
LS
: (4 + 0) / 2 = 2.0 V DC
Now generator 1 decreases the load to match the voltage on the load sharing line (in this example, 2.0 V DC). Generator 2
increases the load to match the 2.0 V DC.
The new load share situation is:
Generator
Actual load Voltage on load sharing line
Generator 1 50 % 2.0 V DC
Generator 2 50 % 2.0 V DC
Example 2: Different generator size
If the generator size differs, the load sharing is still done based on a percentage of the nominal power.
Two generators supply the busbar. The total load is 550 kW.
Generator
Nominal power Actual load Voltage on load sharing line
Generator 1 1000 kW 500 kW 2.0 V DC
Generator 2 100 kW 50 kW 2.0 V DC
Both generators are supplying 50 % of their nominal power.
DESIGNER'S HANDBOOK 4189341275A EN Page 112 of 196
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