Switched reluctance motor

Switched reluctance motor with magnetic flux lines

The switched reluctance motor (SRM) is a type of reluctance motor. Unlike brushed DC motors, power is delivered to windings in the stator (case) rather than the rotor. This simplifies mechanical design because power does not have to be delivered to the moving rotor, which eliminates the need for a commutator. However it complicates the electrical design, because a switching system must deliver power to the different windings and limit torque ripple.[1][2] Sources disagree on whether it is a type of stepper motor.[3]

The simplest SRM has the lowest construction cost of any electric motor. Industrial motors may have some cost reduction due to the lack of rotor windings or permanent magnets. Common uses include applications where the rotor must remain stationary for long periods, and in potentially explosive environments such as mining, because no commutation is involved.

The windings in an SRM are electrically isolated from each other, producing higher fault tolerance than induction motors. The optimal drive waveform is not a pure sinusoid, due to the non-linear torque relative to rotor displacement, and the windings' highly position-dependent inductance.

  1. ^ Cite error: The named reference bartos2003feb was invoked but never defined (see the help page).
  2. ^ Stankovic, A.M.; Tadmor, G.; Coric, Coric (6–10 October 1996). Low torque ripple control of current-fed switched reluctance motors. IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting. San Diego, Cal. S2CID 61325620. Retrieved 3 June 2024.[dead link]
  3. ^ Cite error: The named reference bartos2010march1 was invoked but never defined (see the help page).