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Switched Reluctance Motors

Discussion in 'EV (Electric Vehicle) Discussion' started by bwilson4web, Jun 19, 2023.

  1. bwilson4web

    bwilson4web BMW i3 and Model 3

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    A basic educational video, it explains something I'd read about but not understood:


    • High torque at low rpm - very nice for getting off the line. But at higher rpm, PM motors can generate significant reverse voltage limiting the current.
    • Low reverse EMF at high rpm - the rotor field magnetic fields become an inductive motor by effectively cancelling some of the PM fields.
    The correct term is "Internal Permanent Magnet Synchronous Reluctance Motor." I knew Toyota had them in their transaxles but did not understand the physics.

    Bob Wilson
     
    #1 bwilson4web, Jun 19, 2023
    ammdb likes this.
  2. ChapmanF

    ChapmanF Senior Member

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    Did you post this video once before? I had this strong sense of déjà vu watching it.

    Prius magnets got moved into that V-groove shape between Gen 1 and Gen 2, so they've been doing that since 2004, but the New Car Features manual said rather little about the explanation.

    Toyota didn't call either of the MGs a "switched reluctance" design, though they do use that term for the little motor that moves the parking pawl.
     
    #2 ChapmanF, Jun 19, 2023
  3. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I don’t remember posting before as I found the information new.

    I had read the DoE tear down reports on the Prius motors and they had cited ‘field weakening’ without explaining how it worked.

    Bob Wilson
     
    #3 bwilson4web, Jun 20, 2023
  4. ChapmanF

    ChapmanF Senior Member

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    #4 ChapmanF, Jun 20, 2023
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