High Torque Magnetless AC Motor

[Hugh-Falls]

Has anyone been able to get specific information about the motors developed by Chorus Motors plc ? According to press releases, it uses no rare earth metal magnets, only iron and copper in its construction. These motors are supposed to develop higher torque than equivalent PM brushless motors and not be subject to deterioration due to heat build-up.

[MN Driver]

Sounds like an AC motor to me. Brushed DC also doesn't have magnets either and gobs of torque. There are plenty of these on the market and pretty much anyone making an electric car is using either a brushed DC motor and an AC motor.

Honda went with a perm magnet brushless DC was for weight and size savings over other options.

[Hugh-Falls]

Originally Posted by MN Driver

Sounds like an AC motor to me. Brushed DC also doesn't have magnets either and gobs of torque. There are plenty of these on the market and pretty much anyone making an electric car is using either a brushed DC motor and an AC motor.

Honda went with a perm magnet brushless DC was for weight and size savings over other options.

Yes, it is an AC motor but of a NEW design. Chorus Motors claim it has more torque for its size than a comparable brushless permanent magnet motor (such as the Honda IMA motor) WITHOUT the use of the rare earth metal magnets and without the sensitivity to break down due to overheating. They mention that their design type of motor could break the hold of the Chinese who are now tightening their rare earth metal exports. The Chinese now control most of the world market of these metals, the manufacturing processes and equipment of which we thoughtlessly sold off to them over a decade ago.

[MN Driver]

That is the same for -all- AC motors. They exist everywhere already. AC motors don't have the issues that brushless DC motors like the IMA motors have. Most people using electric motors for electric car conversions DO NOT use a brushless DC motor.

There are plenty out there that promise and deliver the exact the same thing, no overheating magnet death like brushless DC, becuase they ARE AC and have no magnets.

Here is an example of a motor and controller combo that would be plenty sufficient to power our Insights at likely about the same performance, if not better if used with about 35 LiFePO4 batteries(112 volts nominal).

AC-50

High Performance Electric Vehicle Systems (HPEVS, formally HPGC) has been producing these are providing them as about the highest quality, easiest to integrate AC motors out there and pairing them with about the best Curtis controller they make. More performance is coming though because rumor has it that a 650 amp version is coming soon and possibly even a 144v 650 amp version. That would make a small and light car like the Insight, Tercel, Corolla, Echo, Civic, etc fly with no source of performance complaints and be quite efficient and a low running cost and no maintence issues for brushes(which I don't necessarily find to be a big deal in the first place).

About the only cars with electric components in their drivetrains on the road today are hybrids. The EV1 is using an AC motor and the Nissan Leaf is using an AC motor, Tesla is using AC and has a blog post about their decision between AC and BLDC. I -think- the Volt is AC as well but I'm not too sure on the Volt. Most of the auto manufacturers will be using AC motors.

You can watch the AC motor assembly in this video of the Nissan running through its production line. It's look quick and easy to assemble and with full automation.
YouTube - NISSAN LEAF start of production 2-1

I have no concern over the rare earth metals issues for cars, I think there are bigger issues elsewhere than some hybrids not getting a motor. Hopefully such a -crisis- would bring about more use of AC motors and more electric cars instead of hybrids. It appears that every manufacturer is currently working on something. Although I'm not convinced that Toyota is all that dedicated to a pure EV yet.