Permanent Magnet Motors vs Induction Motors
1. The motor is small in size and light in weight
In recent years, with the continuous application of
high-performance permanent magnet materials, the power density of
permanent magnet synchronous motors has been greatly improved. The
output torque of permanent magnet synchronous motors under the same
volume is about 1.7 times that of induction motors.
2. Wide speed range
The permanent magnet synchronous motor based on the special
structure design can adopt the maximum torque/current control
strategy during constant torque operation and adopts the field
weakening control strategy during constant power operation, which
can obtain good speed regulation operation characteristics, and
successfully achieve over 5 times the field weakening speed range.
3. Small moment of inertia, high acceleration can be obtained, and
good dynamic performance
4. Large overload capacity
The rotor of a permanent magnet synchronous motor has no slippage.
When rigid processing is carried out, there will be no surface
effect processing abnormality caused by speed fluctuation.
Applications of Permanent Magnet Synchronous Motor
Permanent magnet synchronous motors have the advantages of simple
structure, small size, high efficiency, and high power factor. It
has been widely used in the metallurgical industry (ironmaking
plant and sintering plant, etc.), ceramic industry (ball mill),
rubber industry (internal mixer), petroleum industry (pumping
unit), textile industry (double twist machine, spinning frame) and
other industries in the medium and low voltage motor.
Permanent magnet synchronous motors can be combined with frequency
converters to form the best open-loop step-less speed control
system, which has been widely used for speed control transmission
equipment in petrochemical, chemical fiber, textile, machinery,
electronics, glass, rubber, packaging, printing, paper making,
printing and dyeing, metallurgy and other industries.
Why choose permanent magnet ac motors?
Permanent magnet AC (PMAC) motors offer several advantages over
other types of motors, including:
High Efficiency: PMAC motors are highly efficient due to the
absence of rotor copper losses and reduced winding losses. They can
achieve efficiencies of up to 97%, resulting in significant energy
savings.
High Power Density: PMAC motors have a higher power density
compared to other motor types, which means they can produce more
power per unit of size and weight. This makes them ideal for
applications where space is limited.
High Torque Density: PMAC motors have a high torque density, which
means they can produce more torque per unit of size and weight.
This makes them ideal for applications where high torque is
required.
Reduced Maintenance: Since PMAC motors have no brushes, they
require less maintenance and have a longer lifespan than other
motor types.
Improved Control: PMAC motors have better speed and torque control
compared to other motor types, making them ideal for applications
where precise control is required.
What are the most appropriate applications?
PMACs will save energy in all motor applications due to their
superior efficiency. The best applications are motors located in
refrigerated spaces, due to the added benefits of reduced
refrigeration load. Note that PMAC motors require variable
frequency drives (VFDs) that are specially made.
What are the savings?
PMAC motors have 15-20% fewer energy losses than a standard NEMA
Premium efficiency induction motor. Replacing just a two-horsepower
induction motor with a PMAC motor in a large cooler would result in
annual energy savings of about 400 kWh between energy and
refrigeration savings. The savings will increase with motor size.
Savings can be larger if the motor regularly operates at lower
loads as PMACs are more efficient at these conditions than other
motors.
What are the non-energy benefits?
The lower operating temp of PMAC motors reduces maintenance needs
and increases equipment life. Their synchronous operation allows
for improved speed control over induction motors. Finally, they
operate at higher power factors.
Environmentally Friendly: PMAC motors are more environmentally
friendly than other motor types since they use rare earth metals,
which are easier to recycle and produce less waste compared to
other motor types.
Overall, the advantages of PMAC motors make them an excellent
choice for a wide range of applications, including electric
vehicles, industrial machinery, and renewable energy systems.
