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Discussion Starter · #1 ·
An interior permanent magnet synchronous reluctance motor is more efficient than an induction motor but is it also more efficient than BLDC permanent magnet motors (of similar size)?
 

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Discussion Starter · #4 ·
From most efficient to least, here’s how the five motor technologies stack up: salient-pole PM, nonsalient PM, synchronous-reluctance, switched-reluctance and, last but not least, induction motors. Regarding power and torque density, as may be expected, the rankings mirror those for efficiency, with the PM designs having the highest torque density and induction designs the least.

 

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An interior permanent magnet synchronous reluctance motor is more efficient than an induction motor but is it also more efficient than BLDC permanent magnet motors (of similar size)?
A quick Google returns:
"There is no major difference in motor control systems of BLDC and PMSM Motors; except the nature of the Drive Current and the detection of the Rotor Position. One of the advantages of PMSM motor is the absence of Torque ripple, which makes these motors more efficient than BLDC. "

And:
"In a PMSM, the windings are distributed over several poles, so producing a voltage waveform that's more more sinusoidal. These differences mean that BLDC motors are slightly cheaper to produce, but may be slightly less efficient, noisier and have more cogging, than PMSMs."
 

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Discussion Starter · #15 · (Edited)
PMSM has distributed windings but Synchronous Reluctance motors have a different rotor which can substitute the permanent magnets for iron, and some including the model 3 have embedded magnets (hallbach arrays) in the iron.



synchronous reluctance iron rotor:



bldc permanent magnet rotor:



model 3 rotor with internal halbach arrays:
 

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Discussion Starter · #19 · (Edited)
exterior rotor (outrunner) motors have higher torque density and efficiency compared to interior rotor (inrunner) motors...


139089
 

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exterior rotor (outrunner) motors have higher torque density and efficiency compared to interior rotor (inrunner) motors...


View attachment 139089
So, as the man says, they are better at powering robots.

Not much relevance to EVs there.
 
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