Yesterday wrapped up my trip to the SMMA Fall Technical Conference and I failed to update the "live blog" (which I have decided never to do again) mostly because I spent many hours in the airport and on a plane. But anyway, I am back in Cambridge now. The trip was definitely a good one for me. I expected to learn a lot, and I did. Here's a few things that I came away with:
- The electric motor industry is very big, reaching out into many markets. The biggest ones seems to be industrial (big constant duty induction motors) and automotive (little accessory PM motors, not traction). But both of those markets took a big hit. The "new markets" are renewable generation (wind) and automotive traction. Almost everyone identified these markets, but few have stepped into them yet, it seems.
- There was a very interesting idea proposed by EMERF for a pre-competitive research consortium that could maybe focus on some of these new markets, or on PM issues. The thing that comes to mind for me is the FEMMulator. Here's what I mean: The "industry" is slow, and built on a large pool of experience and expertise and data from existing designs. And then there's the FEMMulator...a free program that one person wrote to run an iterative FEA design simulation on a brushless motor. Here's the "disruptive technology," except instead of a technology it's really more of a disruptive methodology. The idea that anyone can get access to enough information and computing power to design a motor these days means that the process is different...and a collaborative research intiative seems to make sense, IMO.
- On the technical side, there are a lot of things I know now that I will have to look at more closely. For one, segmented drive PWM. I thought I knew all there was to know about PWM in an h-bridge or inverter, but apparently not. So I will look into the more interesting methods and see if they could be applied to my controller at all. Also, there is a commercial sensorless zero-speed-start BLDC controller available call the DPFlex, from Agile Systems. It uses variations in inductance to measure starting position of the rotor. I knew this was possible and had been researched, but it's interesting to see one in production. I wonder if I could get my hands on one for cheap...or else it's good at least to know that it exists.
- There were also some ideas that were met with a bit of skepticism. There was QM Power, which, well I understand where the skepticism comes from. I actually thought their presentation was pretty good, but after going back and reading their website...their idea is either ridiculous or they do have a clever breakthrough and need to fire their entire marketing/promotional team for making it sound ridiculous. There's also a clever idea for a harmonic drive motor, which is like a harmonic drive gearbox but without the strain wave generator...you use electromagnetic forces to move the spline. That one is really clever, and it would certainly work. The question is how efficient it would be. But it would be great for robot actuators, etc.
- I got some good feedback on the axial motor concept. It's fairly unique even among axial motors, and most people think it could get very good power/torque density. Interesting to see how it works out.
Shane,
ReplyDeleteIt is good to hear that you got some positive feedback on the axial motor design. As someone who has been looking at automotive traction motors, the feeling I get is that we already know all there is to know and here is what we have. In other words, no one is looking to see if maybe there is a better way to do it. Sure seems to me (a layman) that your idea has a lot of promise. I mean, there has to be a reason why all the RC folks are using BLDC motors, specifically the high power, good efficiency, low weight. Anyway, still following with great interest.