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Multiple gen-sets with load sharing
In this application the units are enabled to share the
active and reactive load equally in percentage of the
nominal power. The load sharing is active when each
gen-set is running in island mode and the generator
breaker is closed.
Multiple gen-sets with power management
(PMS)
PMS (= Power Management System) is a system that
will automatically start and stop generators based on
the actual load dependency. This will be done through
a PMS communication between the different units
connected.
PMS applications are always in combination with
AUTO mode. If the SEMI-AUTO mode is selected,
the PMS operation will NOT function! The
Qc4002™ MkII controllers from the gensets need to
be programmed as PMS in AUTO mode. When a Qc
Mains controller is installed this needs to be
programmed in the application that is required (AMF,
LTO, FP, MPE) and AUTO mode.
Installations are possible with stand-alone generators
or with the Mains (extra Qc4002™ MkII Mains is
then needed). A number of Qc4002™ MkII units are
being used in the power management application, i.e.
one for each mains breaker (Qc4002™ MkII mains
controller), if installed, and one for each generator
(Qc4002™ MkII genset controller). All units
communicate by means of an internal CANbus
connection.
In an application with PMS it is important to program
correctly the Start and Stop signals between the
different generators because of the following reasons:
– The maximum load step needs to be programmed
in the Qc4002™ MkII controllers. This never may
exceed the power reserve of the running
generators. Otherwise the gensets will go in
overload with a sudden max. load increase before
the next generator is started up and connected to
the busbar.
– To prevent the gensets to run in a start - stop loop.
The start signal is the value of the maximum required
load step.
The stop signal is the value when the generator should
be stopped automatically.
Example: Installation with 3 gensets
G1 = 300 kW; G2 = 200 kW; G3 = 200 kW.
– Start signal is set at 90 kW (maximum load step
< 90 kW).
Start signal if:
Total Power needed > (total available power of
running gensets -set point start signal).
• Only G1 is running; at 210 kW load (300 kW
- 90 kW) => G2 will be started.
• G1 & G2 are running; at 410 kW load (200 kW
+ 300 kW - 90 kW) => G3 will be started.
– Stop signal is set at 100 kW and priority is set as
(high) G1 > G2 > G3 (low).
Stop signal if:
Total Power needed < (Total available power of
running gensets - Power of generator with lowest
priority - set point stop signal).
• G1 & G2 & G3 are running; at 400 kW
(700 kW - 200 kW - 100 kW) => G3 will be
stopped.
• G1 & G2 are running; at 200 kW (500 kW -
200 kW - 100 kW) => G2 will be stopped.
By programming the parameters in
AUTO mode, the generator can
start up immediately. It is
recommended to place the generator
in SEMI-AUTO mode while
programming all the PMS
parameters !
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