Paul & Sabrina's cheap DIY 144v motor controller

[wakinyantanka]

Originally Posted by MPaulHolmes

OK, it's ready to order you guys. Adam found 3 things I overlooked, and I am so grateful that he looked it over! Thank you Adam! It was that dang SR portion. All the safety features were only done with 1 isolated 12v supply in place, but for SR, you need 2 isolated supplies, so you have to check for undervoltage and such for both. It's supposed to take 5 days, and then a few days to ship to me, so not too long.

Nice work Paul. I have wanted to start on building my controller and simply put I have no spare time to do so. All my time is going into finishing the body of my car. Oh, props to Adam as well, nice work.
So how much power are we talking about with this controller? Just curious.

[MPaulHolmes]

No way! Nevyn did NOT just fake quote me. OHHHHHH You have a karate chop sandwich with extra mayo with your name on it, Mister! I'll email that stuff to you later.

wakinyantanka: approximately 1.21 gigawatts. of power. That's continuous, not peak! Well, OK, not quite... more like 144kW peak, which is about 201 HP. That's what I'm hoping for. The length of the peak would be related to how well the heat could be removed. And that would be related to the heat spreader size.

[wakinyantanka]

Originally Posted by MPaulHolmes

No way! Nevyn did NOT just fake quote me. OHHHHHH You have a karate chop sandwich with extra mayo with your name on it, Mister! I'll email that stuff to you later.

wakinyantanka: approximately 1.21 gigawatts. of power. That's continuous, not peak! Well, OK, not quite... more like 144kW peak, which is about 201 HP. That's what I'm hoping for. The length of the peak would be related to how well the heat could be removed. And that would be related to the heat spreader size.

So liquid cooling will help.

[jmcginley]

Hey Paul,

I drove the truck today for the first time! Not very far and only on 48 volts for the moment, but the controller is working great so far! Thanks for all your work with this. YA!

John

[MPaulHolmes]

Oh thank goodness. It feels like I'm passing a kidney stone every time someone tells me how a controller is doing.

[Flatmann100]

Hey Paul,

here's a little something to settle your nerves: My car is doing fine. The drive to work is sometimes crazy: 0-55 mph, dodging trucks, flooring it to 385 amps going uphill and only reaching 38 mph, then down the other side at 60 with my foot off the throttle. The controller only gets warm. The drive home is way better as I have the roads all to myself. 1,600 miles and humming.

Mike

[MPaulHolmes]

Mike! That doesn't make me feel better! You should tell me that you take it out of the car each night, and lay it in it's own little baby bed, and then power it with a AA battery, in order to control the brightness of an LED. THEN I'll feel better. hahaha.

[Flatmann100]

Paul, sorry there's not more drama but the controller workers so well. I show it off to more people every week at work. What I'd like to do is get my hands on a 9" motor so could unleash the animal in it. As it is I'll have to be satisfied with 0-40 mph in 12 seconds. I'm keeping in touch by reading what your guys are up too. Next year I'll start building the e-pickup. That 1000 amp unit your working on may very well be the unit controlling it if everything goes according to plan.

[MPaulHolmes]

So, I ordered all the parts for a prototype SR control board. There's a lot to do! milling a new tiny board for the surface mount current sensor, since the LEM can only go up to 900 amps (but isn't linear all the way up there I think). Then I have to figure out the correct distance for the new Melexis current sensor to sit above the board. I'm thinking it will be about 1/4" above the pcb, since the 7mT one had to sit 0.75" above, and this one is good to about 25mT of range. That would be 4 pieces of PCB.

I need to test the SR software, and Adam had a good idea with that. I'll just use an IGBT! The dead time will probably be larger than with the mosfets, as they are harder to turn on and off, or so I hear, but we'll see. Dead time is just a variable in the code. Oh no, I have to change a whole number. hahaha.

I'm thinking that the SR controller's main strength won't be that it will use so much less heat by replacing th ediodes with mosfets, but rather replacing the 60amp freewheel diodes with 230 amp freewheel mosfets. Oh heck ya. I also need to figure out how low of a gate resistor I can get away with, with each driver driving 5 of the gigamos mosfets. It will be interesting to see how heating works. derating to 50% would be 1150 amps. I can't wait to see how they perform. I have 25 of them just sitting in the garage waiting to be tested!

[Nevyn]

The parts list for SR Controller Revision 1.0 is in that email you sent, right?