2000-01-0132 Integrated Motor Drive Unit A Mechatronics ... - Delphi

with the 2D model results. The FET's used in this application
can not exceed 175°C. A 3D model is necessary to
assess if this condition can be met.
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Figure 7. 3D Model Dimensions
The temperature of the silicon in the one mm thick copper
model reached 174°C. When the copper layer is
increased to two mm thick the temperature is reduced by
seven degrees. Obviously the goal of keeping the temperature
of the silicon below 175°C can be achieved with
this design concept.
THE NATURE OF MECHATRONIC DESIGN
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The design of most complex systems is achieved by
breaking the various parts into pieces that can be
designed independently. The design of each sub part
may be completed by an individual working on each part
in series, or by several teams that complete the parts in
parallel. When the design of all the sub parts is completed
they are combined together to make a complete
system.
Highly integrated designs, such as the one presented
here, make dividing up the design into sub parts very difficult.
Each and every part becomes highly dependent on
the others. Members of the design team may no longer
work independently, and everyone working on the project
must have a strong understanding of the entire system.
The challenges to integration extend beyond the design
process. Electric motors and their controllers are often
produced in separate manufacturing facilities. Sometimes,
different corporations may even produce the two
parts. Because of the high integration achieved in
designs such as this one it becomes necessary to combine
the manufacturing operations. Often the manufactur-
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ing processes are not compatible with each other. For
example, motors require heavy metal working operations
that are inherently dirty, but electronics requires a very
clean environment.
Highly integrated designs can be extremely sensitive to
changes in requirements. For example, suppose the
torque output requirement for this motor was increased
by 50 percent. This would require an increase in current
through the motor. This would necessitate doubling the
number of silicon devices to handle the current. Because
there is no more room for these devices the whole design
concept would require re-evaluation. A less integrated
design would likely be more easily adapted to such
changes.
Highly integrated designs have many potential advantages,
but they must be weighed against the added complexities
during design and manufacturing.
CONCLUSION
This design achieves a tight integration between an electric
motor and its controller. This results in a very small
system package. Problems associated with interconnecting
wires are minimized. The viability of the novel thermal
management approach is shown through finite element
analysis.
CONTACT
Jeffrey H. Burns
Advanced Project Engineer
Advanced Engineering
Delco Electonics Systems
World Headquarters
M/C D28
One Corporate Center
P.O. Box 9005
Kokomo, Indiana
46904-9005 USA
Tel: 765.451.3279
Fax: 765.451.3600
Email: Jeff.H.Burns@delphiauto.com
Suresh K. Chengalva
Project Engineer
Advanced Engineering
Delco Electonics Systems
World Headquarters
M/C D28
One Corporate Center
P.O. Box 9005
Kokomo, Indiana
46904-9005 USA
Tel: 765.451.3278
Fax: 765.451.3600
Email: Suresh.K.Chengalva@delphiauto.com