Controller mods or build for E-assist altermotor

[cajunfj40]

Hello thingstodo,

Paul's AC Controller already does a good deal of what is described - vector mode control of AC induction motors, control of BLDC.

The V/F or volts/herz controller is much simpler and can run without an encoder, resolver, etc. It is less efficient. But it will run multiple motors in parallel from a single controller. I have more to investigate about doing 4WD in V/F and how much the wheels will slip - the question being whether the front wheels can pull but still spin at different speeds for corners.

IIRC, you'll get different slip in the motors at different corners as they travel at different speeds around a turn. Might have more torque on the inside wheel in a turn, though, if torque goes up with slip. Should be enough differentiation for corners, but might act like a clutch-type posi or mechanical locker when accelerating/decelerating. Odd handling on slick surfaces.

I think this BAS alternator/generator is a good fit. I have one of Paul's AC controllers (serial #2 I think) and I'd like to try it. The firmware may need to be changed if I find something that won't work.

As always, the connection between the motor and the wheel is my problem. I'm not good at mechanical things. You'd think I'd be able to get a belt drive working .. perhaps with a very simple tensioner that let the belt slip if there was too much load?

It's got a 7-rib serpentine belt pulley bolted onto it already. Given the RPM figures I listed, you'll want a 4:1 or better reduction ratio depending on the revs/mile of your tire and desired top speed. Describe your desired layout and I can help with figuring out how to hook it up mechanically. You don't want the belt to slip - you want the tires to do that. GM uses an aramid-fiber core *fan belt* to transmit this power without slipping - shouldn't be that hard to rig something up.

I will call my local wrecker this afternoon. Perhaps they have one of these E-assist motors available nearby. If I could pick one up Monday that would be AWESOME.

Good luck!

[teoman]

Should one be able to replace an alternator with this unit. Is is possible to run in pure ev mode? Say when one is crawling in traffic? Or would it need the engine to be constantly on?

[thingstodo]

Originally Posted by cajunfj40

I'm interested in an inexpensive controller circuit that can take single-phase 240VAC and make 3-phase power to run this motor. All I need is soft-start - variable speed is a bonus. I have a snowblower that wants converting...

Me too! That was a project that has been shelved since the ICE engine blew up/would not start ... almost 10 years ago

[thingstodo]

Originally Posted by teoman

Should one be able to replace an alternator with this unit. Is is possible to run in pure ev mode? Say when one is crawling in traffic? Or would it need the engine to be constantly on?

I would think 15 HP would be enough to crawl in traffic .. if you can get enough torque to start your vehicle from a stand still.

It may be interesting to figure out how to open the input/exhaust ports on your engine so that it will free-wheel

[cajunfj40]

Hello teoman,

Should one be able to replace an alternator with this unit. Is is possible to run in pure ev mode? Say when one is crawling in traffic? Or would it need the engine to be constantly on?

If you bolt this BAS device on your vehicle in place of your existing alternator, the only way to run in pure EV mode is to rotate the engine without injecting gasoline. This adds a lot of friction, and isn't entirely unlike moving your car around using the starter motor. You could do it this way to make your vehicle an auto-stop/mild hybrid type vehicle, though.

If you want to use this BAS (Belt Alternator Starter) device to allow "crawling in traffic" or similar in pure EV mode without turning the engine, it gets complicated. You need to hook up this BAS device between the engine's clutch or torque converter and the input to your transmission. That way you can have the clutch in or the torque converter unlocked and creep along with just the BAS. Keeping the clutch in will be interesting to figure out, maybe a line lock would work. More wear on the throwout bearing, though. You'll probably be limited to first gear and a pretty low top speed. 15hp in a car isn't much. Note that with an automatic transmission you will need at least a fluid pressure accumulator, probably a supplemental electric fluid pressure pump. If you look at GM's description of the eAssist system, they describe having an electric fluid pressure pump for the transmission to keep it happy.

Hooking it up anywhere else in the driveline would be even more complicated.

If you want to use this BAS as a pure EV motor, with no engine, it might have enough oomph to replace a stock 1200cc VW Beetle engine in a VW Beetle or vehicle based on that chassis/similar weight. And run at 2-3x voltage. Or put it in a motorcycle, which I think might be the OP's goal.

Hello thingstodo,

Me too! That was a project that has been shelved since the ICE engine blew up/would not start ... almost 10 years ago

5hp compressor-duty 240VAC single-phase motor and ~30-40ft of nice flexible outdoor-rated 30A cable is plan A. This BAS is ~1/2 to 1/3 the cost or so of said motor, and is overbuilt for the purpose. 240V is enough to run this motor to ~9krpm, so gearing it down will be more complex, and the controller is needed. Might stick with the single-phase AC motor.

A battery-powered lawn tractor, though...

I would think 15 HP would be enough to crawl in traffic .. if you can get enough torque to start your vehicle from a stand still.

55 ft-lb at 0RPM with a 2:1 gear reduction? In first gear? Should be plenty.

It may be interesting to figure out how to open the input/exhaust ports on your engine so that it will free-wheel

Could help.

[HaroldinCR]

Quick note then back to the salt mine. This is a switched reluctance altermotor, not a pure inductance motor.. The stator PULLS the rotor around instead of pushing it.

I read a topic recently, where the Denso Alternator looks to be made the same way as this, using copper hairpins, and, the author stated he was separately exciting the rotor, SePex controller ??

[thingstodo]

Originally Posted by cajunfj40

Hello thingstodo,

Hi

IIRC, you'll get different slip in the motors at different corners as they travel at different speeds around a turn. Might have more torque on the inside wheel in a turn, though, if torque goes up with slip. Should be enough differentiation for corners, but might act like a clutch-type posi or mechanical locker when accelerating/decelerating. Odd handling on slick surfaces.

The inside wheel should have more torque, since it has more slip. Breakdown torque on an induction motor is 3.5 - 4 times rated torque ... but each motor seems to have it's own base speed. We have ACIM on all of our equipment (at work) and changing out a motor DOES change the speed that the motor runs when lightly loaded. Loaded - it's only a few rpm.

But if the inner wheel is pulling hard the outer wheel should be OK going along for the ride?

It's got a 7-rib serpentine belt pulley bolted onto it already. Given the RPM figures I listed, you'll want a 4:1 or better reduction ratio depending on the revs/mile of your tire and desired top speed. Describe your desired layout and I can help with figuring out how to hook it up mechanically.

My existing/planned setup is only RWD. A warp9 DC motor coupled to a 2002 Honda civic gearbox ... and obviously a DC Controller. I am planning to use it as a Side by side Quad/offroad buggy. Top end or redline (5500 motor rpm) in second gear would be in the 50 mph/80 kph range.

Going to 4 of these motors, one per wheel, driven by one AC controller and battery pack would be great for traction and control. The tires on it give about 1000 revs per mile. 1000 rpm on the wheels = 60 mph. So if I went for .. 20 mph? .. that's 333 rpm. And if I limited to 3000 motor rpm ... I could go as high as 9:1. I have read elsewhere that anything more than 3:1 would require 2 stages, which complicates things.

Belt slip may be bad. I am thinking $10 belts and single drive pulleys. I guess I am assuming that the belt tensioner would let the belts slip if you go over the rated torque? Maybe that's a bad assumption.

You don't want the belt to slip - you want the tires to do that. GM uses an aramid-fiber core *fan belt* to transmit this power without slipping - shouldn't be that hard to rig something up.

Sounds expensive. Maybe I should look around for a spare belt?

[HaroldinCR]

In my experience, if a V belt starts to slip, you COULD burn it just a tad thinner in that one spot and it would only get worse from then on.

I'm planning the cog "timing" type belt on my reverse trike. I have 2 hills that I need to get a run at and 1 is dirt/rocks just below our house. Check ebay for belts. I bought a used Can Am Spyder rear pulley and will get a couple different sizes for the motor shaft.

[teoman]

Thanks for the info.

How much of an efficiency loss would I experience?

And what about start stop? How would one go about that? Reroute starter motor to the BAS? Or have a fancier mechanism of injector cutoff an re-enable once the car is moving? (unfortunately the car is a 2003 MB ML350 with a 3.7L engine and an automatic transmission, it has 4WD).


For a motorbike conversion a shaft drive BMW would be awesome. I have an R1200GS and an R26 among others. But the shaft drive of the R26 would make it almost a drop in replacement for the motor (did not have a look at the rpms yet).

[Stubby79]

Timing belt: 98% efficient.
Serpentine belt: 98% efficient.
V-Belt: 96% efficient.

Slippage on any of them will completely kill efficiency. Timing belt wont slip, though, unless it loses all tension.

I favor the idea of serpentine belts, as, thanks to the auto industry, you can get practically any size you want, on the cheap. Pulleys can be salvaged cheap as well. And they can transfer a lot of power...a supercharger can suck back 20+ horsepower, and most of them are run with a plain old 6-ribbed serpentine belt.