Lenze's new international sales structure
Lenze's new international sales structure
Lenze's new international sales structure
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12<br />
New three-phase AC motors<br />
for inverter operation<br />
More power costs more money. Electromechanical solutions have become a thing of the past. As a<br />
specialist in drive and automation technology, Lenze has developed the <strong>new</strong> MF L-force three-phase<br />
AC motors as part of its innovative drive package. These motors offer high energy efficiency, more<br />
dynamic performance and power density, and a wide range of speed settings at astonishingly low<br />
initial costs.<br />
The controlled operation of electric motors is gaining<br />
more and more ground. More than 30 % of <strong>new</strong> installations<br />
are now equipped with inverter technology. In the<br />
past, either traditional three-phase AC motors or classic<br />
servo motors, synchronous or asynchronous, were used<br />
for this mode of operation. And, until recently, there was<br />
no solution in sight that would unite the advantages of<br />
both types of motors.<br />
Three-phase AC and servo motors compared<br />
Normal three-phase AC motors are produced in large<br />
quantities and have a relatively simple construction,<br />
hence a low cost price. However, they are usually operated<br />
on 50 Hz or 60 Hz mains or designed for the conditions<br />
on such networks. If used for frequency inverter<br />
operation, then it is often with nothing more than a better<br />
type of winding insulation. The result is a lower<br />
power density. Compared to a servo motor of the same<br />
power, three-phase AC motors are larger with lower<br />
dynamic performance. The setting range within which<br />
they can be operated with a frequency inverter at a constant<br />
torque is approximately 1 : 15.<br />
By contrast, servo motors are designed for a wide setting<br />
range and high dynamic performance. They are considerably<br />
more compact than three-phase AC motors of the<br />
same power. Their high efficiency means equally high<br />
energy efficiency. Unfortunately, these are advantages<br />
that can be enjoyed only if one accepts the substantially<br />
higher purchase price.<br />
Until recently there was no ideal motor for the many<br />
controlled drives that did not require the extremely high<br />
dynamic performance of a servo motor. The usual practice<br />
was to resort to a traditional three-phase AC motor with<br />
winding suitable for a frequency inverter. The actual<br />
potential for frequency inverter operation went unused.
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