AT ISSUE
There is a common misconception that a distribution transformer
with copper windings is in some way more efficient, more reliable,
or has higher short circuit strength when compared to a transformer
with aluminum windings.
RECOMMENDATION
Improvements in technology regarding the use of aluminum in transformers
have made aluminum-wound transformers the ideal choice for today’s
applications.
RATIONALE Operating
Cost - Cooper Power Systems
designs aluminum-wound transformers with windings of a larger
cross-sectional area than would be used for a copper wound unit.
This larger cross-sectional area translates to a lower current
density, and an equivalent operating temperature. By reducing
the current density in the windings, a low-loss design can be
achieved with aluminum or copper windings.
Reliability
- A transformer’s
life is defined by the life of its insulation system. Because
Cooper aluminum-wound and copper-wound units run at equivalent
operating temperatures, the insulation systems age at the same
rate for each design.
Lower
Cost First - Whether
low losses are the goal or not, aluminum windings are less expensive
than copper windings. The following example shows two equivalent-loss
designs, on with aluminum windings and one with copper windings.
In this example, the losses are
roughly equivalent, but the price of the aluminum-wound unit
is over $4,500 (19%) less expensive.
THE BOTTOM LINE
Cooper Power Systems designs its aluminum-wound coils using the
same thermal, dielectric and mechanical performance requirements
as for its copper-wound coils. In padmount and substation designs,
Cooper aluminum-wound units and copper-wound units serve their
loads equally well.
This
comparison article provided by Cooper Power Systems. For an article
by Sola/Hevi-Duty, click
here.
For more information, e-mail
us.
Operating
Cost - Cooper Power Systems
designs aluminum-wound transformers with windings of a larger
cross-sectional area than would be used for a copper wound unit.
This larger cross-sectional area translates to a lower current
density, and an equivalent operating temperature. By reducing
the current density in the windings, a low-loss design can be
achieved with aluminum or copper windings.
Reliability
- A transformer’s
life is defined by the life of its insulation system. Because
Cooper aluminum-wound and copper-wound units run at equivalent
operating temperatures, the insulation systems age at the same
rate for each design.
Lower
Cost First - Whether
low losses are the goal or not, aluminum windings are less expensive
than copper windings. The following example shows two equivalent-loss
designs, on with aluminum windings and one with copper windings.