Switched Reluctance Motor

[dkmacmillan]

Anyone know where to find a switched reluctance motor suitable for a electric car? I've been googling for a couple of days & can't find anyone who has done this. I'm interested because they've tweaked to an efficiency rating of 97% in some cases.

http://www.freescale.com/webapp/sps/sit ... R&tid=tMfp

[Bob Boyce]

Hey there Ken

Why not check out a Lynch style permanent magnet DC motor. Typical VO is 24-48 VDC with a peak VO of 60 VDC. Nominal current draw is like 330 Amps at full rated output. It is a pancake motor design with a very wide torque band, and very high efficiency as well. There are no traditional windings or commutator. The brushes contact both ends of large bars that are in the armature. The motor can be timed for better torque/efficiency in one direction over the other, or neutrally timed for balanced torque/efficiency, by bolts on the motor case exterior.

Briggs & Stratton licensed the Lynch design and is manufacturing them here in the US under the Etek name for NEV/golf cart use. Just don't mention you want to use it for an electric vehicle when you place your order. There is some stipulation in their license that excludes them from supplying anyone but OEMs for electric vehicle use. They are available through robotics suppliers for use in battle bots.

I placed my order through NPC Robotics. They have a deal with Briggs where they custom order a more powerful version with beefier bearings, and a 1" shaft diameter. Just be sure to specify the 1" shaft option.

Be prepared to use a good electronic speed control because that motor is capable of delivering a lot more power than the published continuous ratings, and it takes a lot of amps when you push it to perform.

I bought an Alltrax AXE Model 7246, rated for 24-72 VDC @ up to 450 Amps continuous maximum. My traction battery bank is nominal 48 VDC with a peak charge voltage of near 60 VDC. I use a Curtis IN916 digital charge meter installed in the instrument cluster in place of the factory fuel guage.

Bob

[dkmacmillan]

Thanks for the info, I'll look into them.

[dkmacmillan]

I found a SR motor rated at 24 hp but it costs a hefty $3350.00. That's without the rest of the electronics. The Lynch style is only $400.00. Even at 94% efficiency it's not worth it.

http://www.rockymountaintechnologies.com/index.htm

[Bob Boyce]

Oh, I forgot to mention, electric motor horsepower is rated by electrical power consumption, 746 watts = 1 horsepower, instead of mechanical shaft horsepower. Some manufacturers tend to fudge numbers so much when they calculate electrical to mechanical conversion efficiency that published efficiency ratings may not be reliable.

Don't you just love the low price of the Etek motor compared to the other even way less efficient series or shunt wound motors?

Bob

[dkmacmillan]

Rocky Mountain doesn't seem to have anything about wattage posted on their website. If the price was comparable I'd call them up & get some facts. I don't know a lot about electronics. I'm supposed to come into some money in a couple of months, if it happens I'm going to take a class on it.

[maxc]