# What is Regenerative controller?



## major (Apr 4, 2008)

brandon0409 said:


> but when it comes to EV's is the battery actually being regenerated to the point where the battery is continuously being recharged or is it constantly repairing the battery to make it as new again. Please clarify.
> 
> Thanks


Hi brandon,

The terminology in the EV community of "regenerative controller" refers to a motor controller which is capable of exciting the motor during the deceleration of the vehicle (braking) in such a manner that it becomes a generator for that period applying torque against motion and converting the kinetic energy of the moving vehicle into electrical energy which is in turn fed to the battery to recharge. Most often called regenerative braking or simply regen. This can be applied to slow down the vehicle or to maintain a desired speed when going downhill where you would normally see an increase in speed due to gravity. Regen takes energy from the moving vehicle, so cannot be used during constant speed motion unless you have another power source, such as a fuel fired engine, in which case you now have a hybrid.

Regards,

major


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## brandon0409 (Sep 26, 2008)

What's the difference in cost between a regen controller and a regualar one?

Is there alot of extra modifications that must be made to the conversion to use this sort of controller?

What is the difference in cost with a "permanent magnet DC motor" and a "standard motor"?


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## major (Apr 4, 2008)

brandon0409 said:


> What's the difference in cost between a regen controller and a regualar one?


Depends on the system and the vendor. For AC drives and SepEx, there is no additional cost.



> Is there alot of extra modifications that must be made to the conversion to use this sort of controller?


Usually not.



> What is the difference in cost with a "permanent magnet DC motor" and a "standard motor"?


I don't think there is a "standard motor". I personally don't recommend PM motors for EV propulsion.

You need to do some research on your own. Read a book on EV conversions or something.

If you're looking to convert a car, consider most guys are successful using series wound motors and PWM controllers. It is difficult to get regeneration from that combination. Very few attempt it with series motors. Regen is nice, but it may require to select a motor and drive for your conversion that is several times more costly than the series wound motor. And you'd be able to get the same net result (range) by just using a 10% bigger battery with the series motor.

Regards,

major


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