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Motor controller to run a Vectrix motor.

Posted: Tue, 07 Apr 2020, 18:33
by wovenrovings
Hi All,
I have a spare vectrix motor here and I have been thinking about putting it to use in a kind of custom motorbike project.
Having read about Antiscabs 100 000kms and having 4 motor controller failures, I think it would be better to run a different motor controller.
Makes me wonder how long I'll get out of the vectrix I am riding. Anyway just wondered if anyone had any suggestions or experience with running a vectric motor with a different controller.

Cheers
Daniel.

Re: Motor controller to run a Vectrix motor.

Posted: Tue, 07 Apr 2020, 19:28
by antiscab
There was a trike project in south Australia where they used an industrial vfd to drive the original Vectrix motor.

Not practical if keeping the motor on a Vectrix though.

Reliability has improved somewhat. Going to solid copper sleeves instead of mild steel studs gave the biggest improvement. This can be retrofitted to the old mc boards.

More recently, using dugas firmware, some power limits are reduced, meaning the igbt isn't being pushed close to, or I suspect, past it's limits.

I'm at 50'000km on my present motorcontroller.

If using a different motor controller, it needs to be can bus controlled or you lose Regen going to a normal 3 wire throttle.
It also needs to do field oriented motor control, to do that it will need to be compatible with the encoder on the bike.
It will also need to take up to 150vdc input.
I used to think back emf peak reached DC bus voltage at 70kmh. I now think the motor is run closer to induction than I thought.

I never did find an alternative motor controller that wasn't a big bulky vfd

Re: Motor controller to run a Vectrix motor.

Posted: Thu, 09 Apr 2020, 15:14
by wovenrovings
No it won't be on a vectrix. Will do some reading about field orientated control. So it is mostly only used on industrial vfd's? Brief first looks suggests that field orientated control is more efficient, especially at high rpm. Do your standard BLDC or permanent magnet controls just accept that for the simpler controller?

Have looked in the cupboard and it turns out I have a mainboard in there with igbts and a spare set of igbts. So if the igbts were substituted with some higher capacity ones it should be pretty reliable?
From my other thread about max speed, I gather the motor speed limit is part of the firmware for the main board, right?

Re: Motor controller to run a Vectrix motor.

Posted: Fri, 10 Apr 2020, 09:03
by antiscab
found a link to Trev: https://www.autoblog.com/2008/01/23/tre ... own-under/

I would say field oriented control is more efficient across the rpm range, though the bigger advantage is lots more low speed power by doing field strengthening

Simple BLDC not only doesn't do field strengthening or weakening, they're also usually square wave, so lower efficiency.

Bigger IGBT's would help...alot, however, 300A is already the largest unit that will fit on the board. The problem is the DC caps on the input need to be as close as possible to the IGBT terminals. every mm matters, though with a 600v device and only 140v battery, there is a lot of headroom for voltage transients.

yes, speed limit is coded into the motorcontroller firmware

Re: Motor controller to run a Vectrix motor.

Posted: Fri, 10 Apr 2020, 20:08
by francisco.shi
I have a 400A 750v IGBT module with gate drive board that I use in my inverter. Would that be of any use?
IGBT block with gate drive board.
IGBT block with gate drive board.
IMG-20200327-WA0010.jpeg (1.24 MiB) Viewed 380 times

Re: Motor controller to run a Vectrix motor.

Posted: Fri, 10 Apr 2020, 20:19
by wovenrovings
Thanks for the link to Trev. After looking at it I found a link to an old fully charged episode where they drove it. :) https://www.youtube.com/watch?v=E5pUIXe--fc
Can definitely hear the vectrix motor.
Will go do some research and see what I can come up with. Thanks for the info Anitscab.
I am not sure at the moment Francisco, I need to learn more and also work out where I am going with this. Definitely usefull to know though.