DC motors that can generate electricity
DC motors that can generate electricity
(OP)
This is a silly question. What is a DC motor that can also generate electricity?
Typically, how much electricity do these motors generate?
Typically, how much electricity do these motors generate?





RE: DC motors that can generate electricity
RE: DC motors that can generate electricity
I am working on a prototype robot which will get around on wheels. Each wheel has its own motor. So, can I use any DC motor in my machine? Can I expect the batteries to receive a charge, even if it is a small amount, by cutting the power to the motors and let the momentum of the machine turn the wheels?
RE: DC motors that can generate electricity
RE: DC motors that can generate electricity
Is there a type of motor which works better than others for this purpose?
RE: DC motors that can generate electricity
RE: DC motors that can generate electricity
Whether or not you use two way power control probably doesn't influence the motor selection very much. I suspect that the motor voltage, speed and torque requirement will be in a range where a permanent magnet motor would be a good choice. Others here may be able to confirm that or recommend something else.
RE: DC motors that can generate electricity
The main goal for the robot is endurance. It is meant to roam around as long as possible under its own power. It will have as many solar panels to charge its batteries as physically possible.
RE: DC motors that can generate electricity
A robot large enough to carry enough solar cells to charge itself would be a serious impediment to our heavy traffic.
... Until it was stolen, probably in a matter of hours, less if it has visible copper or anything that looks like copper cable.
Sorry, it just seems like a waste of resources and time to make a robot that does nothing useful.
Mike Halloran
Pembroke Pines, FL, USA
RE: DC motors that can generate electricity
For a robot weighing 20 or 50 pounds and travelling slowly, regeneration is probably pointless.
For a robot weighing over 700 or 1000 pounds, travelling over 20 MPH and making rapid starts and stops, regeneration is probably a good idea.
It depends.
BTW, regeneration is common on electric transit vehicles, whether AC or DC drive. (On diesel electric locomotives, with no way to store the regenerated energy it is disipated in resistor banks and provides braking.)
On some light rail transit systems, the linear induction motors regenerate down to very slow speeds.
Regeneration is great for heavy fast vehicles with a lot of start stop cycles, but not very effective for light slow vehicles.
respectfully
RE: DC motors that can generate electricity
RE: DC motors that can generate electricity
RE: DC motors that can generate electricity
Also, with more than one motor, the motors can be reconnected in series for regeneration.
respectfully
RE: DC motors that can generate electricity
In a DC motor, if you apply current to create torque in the opposite direction from the velocity, you will automatically be generating. As sreid pointed out, a 4-quadrant drive will have an electrical path for the generated voltage and current. This path is through the "flyback diodes", and the net effect is to increase the DC bus voltage.
The important question is "now what?". Most industrial systems have pretty significant capacitor banks on the DC bus that can absorb quite a bit of this energy. Your battery bank could absorb it (if not fully charged), but the question is how fast -- what is the charge rate of the battery. Hybrid cars have "supercapacitors" to absorb this energy quickly, then bleed it off into the batteries. I suspect you may want some capacitance on the DC bus. You may even need a shunt resistor to dissipate this energy if the batteries can't take it or take it fast enough.
But as others have said, without knowing your particular situation, we really can't say what is needed in your case.
Curt Wilson
Delta Tau Data Systems
RE: DC motors that can generate electricity
4QD also make an efficient and robust speed controller, with regenerative capability.
RE: DC motors that can generate electricity
I heard Maxon had attain that efficiency, but not supplying motors that went to Mars (this awesome)
RE: DC motors that can generate electricity
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RE: DC motors that can generate electricity