SDMO R 340 U User And Maintenance Manual page 75

The second GS thus coupled initiates its power on ramp (adjustable delay) and the distribution of power among the two generating
sets takes place. Each generating set will then take 50% of the required power, i.e. 225 kW.
When the power required for the application reaches 75% of the power of the two generating sets in operation (GSs at priority 01
and 02), i.e. 900 kW, the third GS (at priority 03) is then started and is synchronised with GS1 and GS2. Its flow is then closed. The
third GS thus coupled initiates its power on ramp (adjustable delay), and the distribution of power among the three generating sets
takes place.
Each generating set will then take 33.33% of the required power, i.e. 300 kW, corresponding to 50% of its rated output (600 kW).
When the power required for the application reaches 75% of the power of the three GSs in operation (GSs at priority 01, 02 and
03), i.e. 1350 kW, the fourth GS (at priority 04) is then started and synchronised with GS1, GS2 and GS3. Its flow is then closed.
The fourth GS thus coupled initiates its power on ramp (adjustable delay) and the distribution of power among the four generating
sets takes place. Each generating set will then take 25% of the power required, i.e. 337.5 kW, corresponding to 56.25% of its rated
output (600 kW).
The power required for the application may continue to increase up to the upper plant limit (95%) of 2400 kW, i.e. 2280 kW
(the setting can be changed). This corresponds of course to the upper generating set limit, i.e. 570 kW (95% of 600 kW).
Automatic operation (All Kerys PLCs in "AUTO" mode) (coupling when stopped)
Loss of grid voltage
• Grid loss acquisition delay (controlled by the mains detection module).
•
Generating set power units switched off.
•
Generating set start request.
• The generating sets' speed increases.
• Speed stabilisation delay.
•
Order of excitation for each generating set at nominal speed; the voltage is then quickly established on the busbar.
•
Start of distribution of active power.
•
Resumption of use at the rated power and frequency.
Wattmetric control
This wattmetric control will be activated after a global operation delay. This global operation enables the application to be resumed
after power is restored to the different outputs, and ensures stability of the load before the wattmetric control is started.
Depending on the power for the application, the number of generating sets in production may vary in order to optimise the
production for consumption.
The procedure is as follows:
•
End of the global operation delay.
•
Start of analysis of the active power consumed.
Example: A generating set must be stopped according to the set thresholds.
•
Power cut at the non-priority generating set, transfer of the power to the generating set(s) remaining in production.
•
Uncoupling of the non-priority generating set, at zero power, by switching on the generating set power unit.
• Cooling delay.
• Generating set stopped and set to standby.
Example of increase in power:
•
Generating set start request.
• The speed of the generating set increases.
• Alternator excitation, the generating set establishes its voltage.
•
Request for synchronisation of the generating set to the busbar (i.e. the other coupled generating sets).
•
Generating set power unit switched off.
Return of grid voltage
•
Grid return acquisition delay (controlled by the mains detection module).
•
Generating set power units switched on.
•
Cooling delay.
• Generating sets stopped and set to standby.
The Kerys PLCs remain in "AUTO" mode
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