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4.4.5.5.6 LDSS with predicted load
For further information, please refer to application examples to ╚═▷ “6.3.15 LDSS with
predicted load” .
Introduction
In case of a mains failure, the usual LDSS function of the easYgen starts either one or all
generators. This is done so because during the mains failure the consumer load
information is lost. The LDSS with predicted load (LDSS PL) can start the correct amount
of generators based on the last mains power measurements (5-minutes average value).
The LDSS PL takes the 5-minutes average value as mains load into account and passes it
to the LDSS function as consumer load. The LDSS function can thereby start the correct
amount of gensets according to that predicted load. A prerequisite for this function is the
availability of a group breaker (GGB) in the application. The GGB allows to switch the
correct amount of generators onto the load.
• The LDSS PL differentiates two source modes as base for the predicted consumer •
load calculation:
◦ 1. Internal source mode: The mains power and breaker handling is provided by ◦
the easYgenXT.
◦ 2. External source mode: The mains power, the MCB and GGB control is ◦
provided by an external device (e.g. ATS), connected via CANopen with
easYgen.
General
To the time the engines are not started and the mains is feeding the load the LDSS PL
calculates a mains load with a 5-minute average value. This load value is passed to the
LDSS function as consumer load. So the LDSS can determine the correct amount of
engines which must be started if a start command becomes active. See
╚═▷ “General” :
Switches are in “Pos.1” and “Pos. A”.
In the moment the start request becomes active the average load calculation is frozen.
See
╚═▷ “General” : switches are in “Pos.2” and “Pos. A”.
If all requested engines are successful started and have closed their GCBs the LDSS PL
gives the release for closing the GGB. From this time on the 5-minute average load
calculation will be fed with the easYgen calculated generator load. See
╚═▷ “General” :
switches are in “Pos.3”; “Pos. B”
The LDSS function now does not differ anymore to the original function. There will be
started and stopped the correct generators according to the common LDSS parameters.
The External and Internal Source Mode
There is an "External" and an "Internal" mode available (configurable by parameter
9066 "Predicted load source"):
The external source mode is dedicated for external installed ATS controls which measure
the mains power. The system allows up to 5 ATS controls at the Interchange point.
In this mode, external ATS controls send information via CANopen RPDO messages. The
easYgen provides information going to the ATS control.
415 easYgen-3000XT Series B37574
4 Configuration
4.4.5.5.6 LDSS with predicted load
Released