Why Switched Reluctance Motors?

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• Why Switched Reluctance Motors?

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Lets Focus on 3 Motor Types

• AC Induction
• Brushless DC
• Switched Reluctance

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AC Induction
Source AC, Brushless, Switched Reluctance Motor
Comparisons James R. Hendershot, Magna Physics
Corporation
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Brushless DC
Source AC, Brushless, Switched Reluctance Motor
Comparisons James R. Hendershot, Magna Physics
Corporation
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Switched Reluctance
Source AC, Brushless, Switched Reluctance Motor
Comparisons James R. Hendershot, Magna Physics
Corporation
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Dimensions, Volumes Weight Comparisons of the 3
Motor Types (NEMA 184 T Frame)
Source AC, Brushless, Switched Reluctance Motor
Comparisons James R. Hendershot, Magna Physics
Corporation
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Motor Comparison for BEVs HEVs
Source Advantages of Switched Reluctance Motor
Applications to EV and HEV Design and Control
Issues M. Ehsani, et al, IEEE Transactions on
Industry Applications, Vol. 36, No 1,
January/February 2000
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What About Noise?
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In Summary

• Due to the absence of rotor windings, SRM is very
  simple to construct, has a low inertia and allows
  an extremely high-speed operation. SRM operates
  in constant torque from zero speed up to the
  rated speed. Above rated speed up to a certain
  speed, the operation is in constant power. The
  range of this constant power operation depends on
  the motor design and its control. Designing a
  motor with high constant power range to base
  speed (e.g. at least 41), is not hard to achieve
  with SRM, and has a great effect in designing a
  lower power motor that can produce significant
  torque.
• The absence of rotor copper loss eliminates the
  problem that the induction motor has associated
  with rotor cooling due to its poor thermal
  effects. The absence of permanent magnets on the
  rotor eliminates the problem that the Brushless
  DC motor has with high temperature environments
  whereby the magnets can lose their magnetization.
• The SRM has many advantages, mostly resulting
  from its simple structure. SRM is normally low
  cost because of its extremely simple
  construction. Moreover, The SRM operation is
  extremely safe and the motor is particularly
  suitable for hazardous environments. The SRM
  drive produces zero or small open circuit voltage
  and short circuit current.
• Furthermore most SRM converters are simple
  because the current is unipolar. The SRM drive is
  immune from shoot through faults, unlike the
  inverters of induction and brushless dc motors.
  Due to the inductive nature of the motor, the
  power factor of the SRM is lower and requires a
  higher rated converter when compared to induction
  or BLDC motors.