making an EV controller? similar to bike... just bigger

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potatonet

100 W
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Sep 9, 2008
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so I know people here feel like making their own electric bike controllers and I think this is a great method for getting the most bang for your buck

am I correct in saying that I could make a brushless DC controller for an electric vehicle using different software programming and much higher rated components?

I have a FWD car that is kind of a project car (it has 300+ hp gasoline right now) and I want to custom attach some hub style brushless wheels to the rear wheels and I need to get a controller/s capable of doing 2 motors at 80-100kw a piece.

the battery pack would be a 30kwh lithium Iron phosphate or lithium titanate (shhhhh) should be between 500-800 lbs. the car weighs 2650 right now and Im going to pull a few things out to make the gain from the other motors and batteries less noticable.

I know some users do 10kw here on their bikes so I dont think that 10x would be that hard (per motor) (other than sourcing the components for the board/s and reprogramming the software, not to mention cooling).
 
In theory, you could just get something like one of the Infineon boards sans the caps and transistors and wire it to a homemade, external power module. You'd need to boost the signal from the FET drivers with some small transistors, though.

However, I'm instinctively leery of this idea for some reason...mebbe someone else can tell me why...:?
 
control of low power is cake....its when you get higher currents/voltages that make everything harder. Signals get very sensitive to noise, current doesn't flow the way you think, back EMF is larger.

two 100kw drives is no trivial task.

Why do you need 2 motors? Do you know of any brushless hub motors? Got any in mind? The ones i've seen are spendy.

Are you wanting AC or DC? Do you have any electronics experience?
 
I would prefer AC but I can deal with DC if need be.

I am going to make the motors, I have a lot of machine experience, an M.S. in engineering, and a bit of electronics experience.

I might just make it DC because of the ease of it but if I feel the need to do AC I can do that instead.

this is going to be a track car so its got to have the power to deal with the weight.

and my cousin works for UQM so I have info from a guy on the inside
 
decide now on AC or DC....they're very different. Also, why hubmotors?

Wwhat area of engineering are you? if you have "a little" experience in electronics, it won't get you far in designing your own controller or hacking something together, you'll spend a lot of time banging your head against the wall. DC controllers are fairly simple, AC controllers require lots of knowledge of phasors, PWM, PFM, timing and programming. Its not something you could just change out the power side for something bigger. Also, designing a motor requires a bit of complex understanding of magnetics...not saying you can't, but its not trivial.
 
My thesis was designing a battery exchange system for electric vehicles, I was working with a sepex DC motor that was rated continuous at 60KW, ancient technology.

I have a good understanding of electronic components but I feel that I could learn more which isnt a hard task for me.

I want to do AC, will stick with this.

I want hub motors because its VERY easy to put hub motors on the rear wheels of my car and I want to keep the stock motor there on the front wheels, possibly run an AWD similar to audi's design with their hybrid, the front motor also will drive a generator for the battery pack when I engage an electromagnetic clutch.

its kinda like frankenstein but I know where everything goes so its ok =-)

my BS was materials but I did mostly mechanical projects with some chemical engineering, my MS is in general engineering because I didnt fit into either the materials entirely or mechanical entirely, so I got GE =-/ it was an ME project though.

I have dont plenty of electronics projects, I feel confident that I could learn what I dont know already.
 
Ok, good... I just wanted to be realistic thats all.... Its the internet, its hard to see people's experience level. It sounds like you're knowledgable in electronics enough to design something from the ground up, and cut out using another controller for the brains. There are lots of chips out there that do all the vector math for you, you provide the power side. It all depends on how quick the timeline is and how deep your pockets are.

I'd start looking into the magnetics and electrical side of designing your own Hubmotor... thats going to be the difficult part... that and making sure its cooled enough (watercooling?).
 
yes they are going to be water cooled

I have the design from UQM for their 150kw systems for the water cooling channels
 
I don't know if I'd advertise that much online.... thats IP, and I'm sure there are patent applications, and I'm sure whoever gave that to you probably violated their NDA.
 
potatonet said:
It's not a patented motor design.
Click to expand...

but its IP and someone had to give that design to you... which looks like it violated their NDA... I don't know of ANY companies that would allow an employee to freely give out a design to anyone, regardless.

All I'm saying is be careful about what you admit to online.... I'd hate to see you get in trouble, I'd rather see you finish a motor and get a vehicle running.
 
will keep that in mind thanks,

whom are you thinking of that sells an AC controller, there are only a few that I know of.

the problem is that most motor/controller systems cost upwards of 40000 dollars.

I would have to seriously modify something to hook one of those up too.
 
http://www.evcomponents.com/ProductDetails.asp?ProductCode=AC55

$3500 for motor/controller.... its an AC55 .... its a nice combo.

I know Siemens makes some, curtis and sevcon make some but likely not enough power for you.
 
There's just not a lot out there that is both cheap and high power...

Here are some to look at:
http://www.enovasystems.com/
http://www.metricmind.com/
http://www.acpropulsion.com/
http://www.electroauto.com/
http://www.evisol.com/

and here's a big list of controllers:
http://www.evalbum.com/cntrl
 
If by track car, you are talking about road racing, 300hp is all ready more than adequate.

Focus your efforts on making the car lighter, and you will have better performance returned to you than more power would provide.


I have a 280whp NA k-series civic hatch. It's 1900lbs. I absolutely break cars in half at the track with it. Cars with 500-700hp and 3000-3500lbs get owned so hard, sometimes I feel bad. Built EVOs, Vettes, Supras, Cobra rustangs, etc etc, they all go down. The only stuff I can't seem to beat is the super light weight stuff, like the super 7 kits. Even when those damn things have 120hp 1970's ford POS crossflow engines in them, they are still the fastest cars around the track, because they are ~900-1100lbs.

Power to weight only helps when accelerating (about 30% of your time around a road course, depends on the track of course). Less weight helps EVERYWHERE (that 30% AND the other 70%). Anytime you add significant weight to a chassis, even if it added a bunch more power to the car, it generally makes the car slower around the track.

But, if it's drag racing, then yeah, if you increase power to weight, and you can get the car to hook, then you made it faster.
 
A little off topic perhaps, but I think it's important to be seen if his goal is to make a faster car, rather than just make a fun electric project (nothing wrong with a fun E-car project).

This is someone with the same car build that I run, only this k-series is mostly stock (and i don't run ghey green wheels..), I think he said he is making ~240whp. I'm making 280whp, but otherwise it's an identical car build.

http://www.youtube.com/watch?v=qhzyBSQmb_c
 
its a 1990 vw corrado, its been lightened quite a bit.

the only things I can do to lighten it further would sacrifice a lot of comfort (door panels, dash, front seat swap, rear panels, etc)

I already have tons of weight with the supercharger and the generator for the battery system (no more alternator its a dc-dc converter).

I could turbo charge the motor instead but that would involve a lot more work but would probably remove a good 30 lbs from the front of the motor.

This is the reason I want the electric in the rear, I can hook up the motor to run the generator and no transmission at a constant RPM just for juice if I need it or just run it on gas till I get enough charge.

my obscure hybrid plug in hybrid design. I wish they had a 100kwh battery pack that didnt weight 1000 lbs and cost 120,000 dollars
 
It would do you well to change to a better suited chasis if you are seeking performance.

This sounds like something that you may spend $15-40k on, only to end up to a car inferior to the stock car.

Pick a chasis that is light and stiff, and uses real suspension (double wishbone) rather than that swing-beam VW super cheapo design. Pick something that is natively light and natively has the room for the battery. Picking something with an engine that is efficient would also be a good call if you are looking to make a serial hybrid. Those VW G60 pumped engine setups are about as bad as it gets for BSFC's.

Very very often in a modified car project, the car itself becomes the cheapest part of the project. It's always a very bad choice to settle on a perticular chasis because it's something you all ready happen to have, when there are alternative chasis avaiable which would be so much better suited towards reaching your goals.

Just providing my $0.02 from building and working on many different car modification projects over the years.

Best Wishes,
-Luke
 
liveforphysics said:
If by track car, you are talking about road racing, 300hp is all ready more than adequate.

Focus your efforts on making the car lighter, and you will have better performance returned to you than more power would provide.


I have a 280whp NA k-series civic hatch. It's 1900lbs. I absolutely break cars in half at the track with it. Cars with 500-700hp and 3000-3500lbs get owned so hard, sometimes I feel bad. Built EVOs, Vettes, Supras, Cobra rustangs, etc etc, they all go down. The only stuff I can't seem to beat is the super light weight stuff, like the super 7 kits. Even when those damn things have 120hp 1970's ford POS crossflow engines in them, they are still the fastest cars around the track, because they are ~900-1100lbs.

Power to weight only helps when accelerating (about 30% of your time around a road course, depends on the track of course). Less weight helps EVERYWHERE (that 30% AND the other 70%). Anytime you add significant weight to a chassis, even if it added a bunch more power to the car, it generally makes the car slower around the track.

But, if it's drag racing, then yeah, if you increase power to weight, and you can get the car to hook, then you made it faster.
Click to expand...

Sounds like a fun car. Is it similar to the White Zombie?
http://www.youtube.com/watch?v=4Cf89tawZX8&feature=related
 
Similar to the white zombie in the way that it's quick, painted white, and doesn't look quick from the outside, but my setups use gas engines not electric power.

My 45mpg k-series civic is also faster than white zombie. It's best pass is 11.40 @ 118mph.


I also built a car which is the same model of car as white zombie, 1969 Datsun 510, but I put the drive train from a Honda S2000 into it rather than electric power. It uses an STi's clutch type LSD rearend, an MR2's steering rack, 280zx turbo brakes, and S2000 engine and 6spd tranny. It sits in the garage mostly though :( It's quick, but I considder it a fail though, because it ended up being 2450lbs, and even with 250bhp, it's just not fun to drive with that much weight. I think I could make it lighter if i re-did all the custom mounting brackets for all the custom parts out of aluminum, but I know that would easily cost me another 5-10k into a project that all ready has 25k into it.
 
haha you have no idea whats in that motor...

its not even close to a G60, that motor and supercharger sucks =-)

the motor is a 2.0L low compression race ported and flowed, balanced and blueprinted, forged everything with a quaife sequential transmission and a lysholm supercharger from a mercedes benz C32 AMG (yes I even have the EM clutch hooked up to various things). I get 32 mpg on the freeway and about 8 mpg on the track when running full bore.

my suspension has been converted to a multilink from an audi TT.

it also has a 10 pt roll cage, its pretty darn stiff.

plus I have no rear seats and the entire trunk space for batteries, it would definitely help me balance the car.

being that I am using a 400-800 lb lithium battery I think that will put it close to 50:50 with the new motors and controller.

I've been frankensteining that car for a LONG time, its definitely a better car that it was stock, right now and with the new motors it would be even more so.

oh yeah and the reason I am using this car is because its unique enough so that people dont know what it is, everyone knows what a datsun 510, there arent too many cars that arent distinguishable
 
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