Thanks for the answer! Metal additive manufacturing is revolutionizing how parts are designed and produced, offering solutions that were impossible just a few years ago. I do not believe that they are perpendicular to the magnets but just look that way. This is entirely due to the geometry of the motor. It’s more well-suited to ones with sinusoidal back EMF, but it can also be used on ones with more trapezoidal back EMF with some of the same benefits.

I suppose the timing could change the computed value of resistance in that way. Thanks again, this is a great blog, I’ll keep watching Thesis ] [ S. It’s the synchronous inductance. I sort-of disagree with the classification system of both the Atmel note and the Wikipedia article. I was looking around for a good explanation of Direct Torque Control and I think my favorite is this: Article on Brushless Motor Terminology Oh, so that’s why they call is a brushless dc motor.

Topic: Permanent Magnet Synchronous Motor Thesis – « The Mind of Bill Porter

Mechanically, the inertia will try to keep spinning, and the rotation will continue to create a back EMF. Shane Colton September 25, at 4: By joining you are opting in to receive e-mail.

james mevey thesis

Posting Guidelines Promoting, selling, recruiting, coursework and thesis posting is forbidden. I just discovered your blog and I am amazed by the quality of this article.


Guillaume December 8, at 6: The 6 FET bridge is between the three phase windings and a bank of caps which supply the adjustable voltage.

Shane Colton: Everything You Ever Wanted to Know About Brushless Motors

The back EMF could even be higher than the voltage applied, extending the speed range of the motor without increasing the DC supply voltage. As they explore options, optical and mechanical engineers are forced to make choices and tradeoffs during the design process. I have an article up at engineering. David Yehuda September 28, at 6: I would have thought from your F.

Force perpendicular to the pole tip’s radius generate torque. Is itimplementing field-oriented control or is it six-step BLDC? Article on Brushless Motor Terminology Brad: The only electrical characteristic I have is a plot of current vs.

Endless Sphere

Thanks a lot, Mevey’s thesis make it obvious, but doxa is heavy to move, thanks!! The motor looks like a resistor in that condition, and most of the power is going into heat in the winding.

james mevey thesis

The James Mevey M. To some extent, I knew this already.

I was very surprised by the “constant” variations, the way I find it is probably too simplistic. If they were perpendicular then yes the torque would cancel assuming constant flux density through the coils between North and South Pole magnets. One of the big benefits of the rotor frame is that the important variables are DC quantities, so you can filter the crap out of them without introducing lag.


Shane, Thank you for sharing the information. Shane Colton December 7, at 3: P They are horribly out of balance from the factory. Guillaume December 7, at 5: It has nothing to do with the controller, which should be obvious although for some reason it’s not since this measurement can be made with nothing attached to the motor at all. Have you written an article about Hall effect or do you have any ideas that can help me? theis

james mevey thesis

The Eng-Tips staff will check this out and take appropriate action. But at zero speed the power out is zero, so the power in is only feeding the resistance. Metal additive manufacturing is revolutionizing how parts are designed and produced, offering solutions that were impossible just a few years ago.

Shane Colton December 8, at I would say it does, but only due to the inertia of the rotor and load. I am puzzled right now