Smart Drive motor as a motor 'and' as a generator?

What do you want the generator to do?  Charge a battery or something?

Basically look for a 4Q motor drive that can do regeneration.  Regeneration/regen/regen braking basically dumps the energy back onto the input line

Hi

At this stage I actually want the generator to do as little as light some bulbs.  I am working on prototyping a new type of transmission system, instead of a gearbox.   So I want to run the motor and then switch it over to a generator.  As mentioned in the original post I would really like to get a full description of what I need to set this up, because, whilst I am learning as quickly as I can, this is outside of my realm of expertise, so specifics and details are what I need.  I am not even sure what a 4Q is.

Cheers

Si

Sorry, had some bad ideas here.

I think you might be able to accomplish this with an h bridge used in a non standard way. I'll look into more tomorrow and post.

Hi

It is sort of like an electric car, except that I anticipate that I would run the motor up to a set speed, and then switch over (relay?) to the generator mode and keep it that way as the input energy (wind turbine or similar) would then keep the generator turning, via the mechanical transmission, which is what I am trying to demonstrate.

I look forward to your further comments.

One big question first, what size and type of motor? That will matter.

I believe our interlocutor is referring  to a BLDC motor:

InstaSPIN-BLDC Solution - INSTASPIN-BLDC - TI Software Folder

Is that the controller you are using?  Wow, that thing can support up to like a 6.6HP motor.

I think you might have a problem with a controller that smart if it doesn't allow the motor to freewheel, it probably does regen braking and everything already, so breaking out your own load braking might be difficult.

If using a large brushless motor like that can support, I suggest using a 3phase bridge and a motor contactor to output to your regen load.  Basically you'll want to disable the drive, not stop it or brake it, to allow the system to freewheel, then on the output of the 3phase bridge turn on the contactor to put the current through your load.

You won't want to run the drive while diverting the current to your regen load though, otherwise you'll just power it from your motor drive.

I'll draw up a diagram in a bit.

Examples of a 3 phase bridge

VS-26MT80 - VISHAY FORMERLY I.R. VS-26MT80 - RECTIFIER, 3 PHASE, 800V, 25A, D-63 | Newark element14 US

and contactor

120-901 - WHITE RODGERS 120-901 - CONTACTOR, SPST-NO, 12VDC, 100A, BRACKET | Newark element14 US

Losses are of great concern in regenerative braking, so sometimes they use synchronous rectifiers.

That contactor could be overkill depending on your regen brake load. You might be able to get away with a smaller relay or mosfet