22-12-2012, 05:59 PM
INTEGRATED STARTER MOTOR GENERATORS
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DC INTEGRATED FLYWHEEL STARTER MOTOR GENERATORS
FOR HYBRID DRIVE SYSTEMS
The integrated starter generator is an advanced electrical machine controlled by electronics and is intended for integration
with internal combustion engines. It replaces the conventional starter motor and alternator, which are the two indispensable
electric units on almost every engine.
This new integrated starter generator offers several new functions so the final users get the following operation modes
from a single integrated starter generator:
• Starter mode for the main internal combustion engine
• DC generator mode for battery charging replacing the alternator
• Electric motor mode for electric propulsion
• Booster electric motor mode as an extra power to the IC engine for better acceleration
Engines equipped with this device will become especially attractive for operation on boats, special vehicles and stationary
generator sets.
By assembly of this integrated starter generator through the mechanical couplings on main engine side as well as on the
gearbox side, the drive system becomes of a hybrid kind that can expand its use into restrictive areas and in general offers
a bigger comfort for the final users.
FEATURES OF FLY WHEEL
STARTER MOTOR GENERATOR
• Four operating modes (starter, generator,
electric propulsion and booster)
• Maintenance free brushless solution
• High efficiency
• High specific power
• 28 V DC output
• Over current and over temperature protection
• Silent operation
• Compact design of electric motor which is integrated
in the flywheel housing
• Eliminates the conventional alternator
and starter motor
• Reduces outline dimensions of the engine
• Provides selectable charging voltage for wet or gel
batteries
• No contactors are requested in electrical connections
The system substitutes some conventional elements
of the engine. These are alternator, starter motor and
flywheel elements. Usually assembly leads to a little
prolongation of the engine but its width becomes
narrower. The stator with windings needs to be
installed in a modified flywheel housing which must
include the cooling tubes for the coolant. The necessary
modifications on the engine flywheel housing and the
coupling to the rotor must be carefully redesigned in
collaboration with both sides engineering.
DESIGN
Iskra's integrated starter motor generator is a threephase
brushless permanent magnet synchronous
machine controlled by power electronics. The system
consist of stator, rotor and a separate electronic
controller which enables control over four different
operational modes namely with functions of starter,
generator, electric propulsion and booster.
Stator
The stator has a three-phase winding on a laminated
pack. The optimized design and high fill factor of the
winding provide improved efficiency, low noise
operation and high output characteristics of the system.
For nominal output power, adequate water-cooling
must be provided through the flywheel housing cooling
tubes.
Rotor
The rotor integrates high-energy rare earth permanent
magnets and without any windings or electrical slip
rings assures long life and maintenance free operation.
It is normally fixed to the engine flywheel with 12
screws. Such assembly needs to be well mechanically
balanced.
Electronic controller - regulator
The electronic controller is located in a separate box
and integrates small signal electronics and power
elements of the most advanced IGBT technology.
In the small signal part of the electronics are flash
microcontrollers which efficiently control the electric
machine and at the same time provide remote control
either through the pins on input connector or through
the CAN buss connector. The power stage is assembled
on a base plate in which the sea water resistant cooling
tubes provide necessary heat dissipation.
For convenience during electric installation the
electronic controller box already carries a fuse, which
is normally in + line with the batteries.
Generator mode
Coupling A must be engaged during
this mode. Generator mode is
engaged immediately after a start or
a boost function has ended. Generator
will provide 5 kW of continuous DC
electric power through the electronic
controller to the batteries and all the
loads on the batteries. The charging
voltage can be selected by pin
condition on input connector and it
can be accommodated to wet or gel
cells with nominal voltage of 24 V.
Available is the option to connect
standard inverters in parallel to the
24V batteries with 230 V 50 Hz or
110 V 60 Hz AC output in those
applications that have loads intended
for AC electricity like many domestic
appliances. Obviously final users will
enjoy such inverter operation when
the main engine is running for longer
periods of time or when stopped for
a limited time depending on battery
capacity.