[badfishracing]

Jack,

The caps are some older Electronic Concepts Film capacitors. 100uf each, around 100A ripple best I can tell. X5.
The Battery (-) goes opposite the motor (-). I was thinking the battery (+) didn't make any difference, but I supposed it still would. That could be revisited.
Had a 15W Dc-Dc, but that wasn't even enough to charge up the first Cap on the IGBT driver. Went with a 40W and that seems to have done the trick.
Not sure what you mean on the Kelvin Emitter resistors? We've got gate resistors 3 Ohm for turn on, and 8.2 ohm for turn off. But haven't put a scope to it yet. Not using the collector shorted sense thing.



Darin

Originally Posted by jackbauer

Nice work Jim! What caps are you using? One thing I did on my controller was to run the battery and motor terminals on opposite ends of the bus bars if that makes sense? Not sure it makes a difference but it should , in theory anyway, allow the devices to share the load more evenly. I also used a vicor 15v 100w dc dc which is major overkill but they were on ebay a year or so back for under $10. You want a really strong voltage source for driving that many igbts. Remember to use resistors of typically 10% of the gate resistance on the kelvin emitters. Those big bus bars will help with heat dissipation but I'd be a bit concerned about using air cooling. That's all I can think of for now

[jackbauer]

The kelvin emitter is the small emitter connection beside the gate connection. Ideally you want about 0.3R between each kelvin emitter and the driver.

[Jimdear2]

Originally Posted by jackbauer;

Those big bus bars will help with heat dissipation but I'd be a bit concerned about using air cooling. That's all I can think of for now

Damian,

A little more detail on the cooling set up. Remember this thing will be under full power for only 20 to 30 seconds. Thanks for your concern though, I always listen to what you have to say.

For now we have everything mounted to a 10x16x2 inch finned heat sink. The plate is 3/8 inch or so thick with the remaining height being fins spaced about 1/4 inch apart. Directly attached to the bottom (fin side) is a 9 inch radiator cooling fan moving air through the fins. I also plan a 120 mm fan mounted in one end cover to move air around those copper bars and components not attached to the heat sink plate.

If that should prove inadequate I will insert 1/4 inch copper tubing in between every third or fourth fins and pot them in using a suitable heat transfer material. To keep the fluid circuit that is in contact with the heat sink short I will manifold it and use 3 or 4 circuits. I have a number of M/C radiators and overflow tanks to do the circuit

What do you think?

Jim

[jackbauer]

I think that will be fine Jim. You have more than enough thermal mass there to take the heat pulses for such short runs.

[Salty9]

Jim,

Have you checked post #97 in this thread? Looks like a possible source for reasonably priced IGBTs and other goodies.

http://www.diyelectriccar.com/forums...-72000p10.html

Chuck

[Jimdear2]

Well, we got back at the controller build up after replacing an IGBT driver board and cap. It appeared that we has a minor bit of magic smoke release during the initial testing, a resistor on a temp breadboard touched. Darin replaced the board and cap so we are getting back to the controller buildup.

For the final assembly we started off by assembling all of the IGBTs to the heat sink. then the front cover with insulators, buss bars and the caps. From there we finalized the mounting of all of the electronic bits.

With all of the stuff installed into the controller we (Darin) did a hook up using the motor fields and three big (bus/train???) breaking resistors. Once we get everything sorted we will hook up the traction battery to the controller and put a load on the controller.

Darin hooked up a scope and found that we still had a problem from one of the IGBT driver boards. Today he traced it back to a damaged trace on the IGBT controller board. After a bit of repair he managed to get things smoothed out.

The following pictures show the controller sequence as we assembled it. Not shown, but installed, is the 4 inch fan installed into the rear cover and the 9 inch fan installed onto the bottom of the fins of the heat sink. The 4 inch fan is hooked in parallel with the precharge system, fan comes on when the precharge is done. The 9 inch will come on when the throttle is applied.

Maybe tomorrow will be the big day. I am electronically challenged so I loet Darin make al of the decisions there. I'm working on all of those last minute fussy little things.

More as we succeed,
Jim

[Jimdear2]

Well today was the big day. We powered up the complete controller with full traction battery power

YIP YIP YIP YIPEE . . . NO SMOKE

Darin got all the minor problems in the controller fixed yesterday. So today, as usual just when we are ready to go we find that the scope is not working, so now he has to fix the scope. We finally got to put some current through all six IGBTs after an hour or so of puttering with the scope.

Started off for the first try with 24 volts and pushed about 300 amps (almost blew a battery).

Darin says the scope trace shows the on off pattern as pretty clean, although he says he may want to try some snubbers (you'll have to ask him what that is) because there was a ??rebound spike???. As I say, I'm electronically challenged.

After we tortured a couple of 12 volt Odyssey's down to 3 volts we switched over to the 165 volt Headway traction battery. Darin set the controller to push some real current. With the limits Darin set into the controller (I may have these numbers a bit mixed up) I think we got right around 1200 motor amps and around 75 motor volts and were pleased to find that the battery only sagged to around 140 volts.

If we get the 2000 motor rpms we are hoping for with this motor voltage, that will give us around 115 peak horsepower and produce some 300 foot pounds of torque at the motor shaft. With a 3 to 1 chain and a 5.14 to 1 diff reduction that's around 2400 foot pounds of torque at the wheels at zero rpm.

The above doesn't really mean anything real (except a lot of broken chains) but it's a lot of fun to speculate.

I forgot my camera today so no pictures. I'll be going back Wednesday and I'll see what I can photograph.

Jim

[Woodsmith]

That is coming along really well, Jim, Darin, really well done.

I do sometimes envy those who can see how the magic smoke works in the little black boxes.

Jim, as an aside, you have a 15.42:1 reduction ratio motor to wheel. How tall are your wheels?
Just trying to guestimate how it compares with my transmission ratios with my 28" and 31" tall tyres.
Cheers.

[Jimdear2]

Originally Posted by Woodsmith

That is coming along really well, Jim, Darin, really well done.

Thanks for the encouraging words. I've got to admit that I wasn't as confident as Darin was about the final result, but he is the electron pusher and "knows".

Originally Posted by Woodsmith

I do sometimes envy those who can see how the magic smoke works in the little black boxes.

That's me as well, I'm pretty much at the level of, duh, the red wire goes here doesn't it?

Originally Posted by Woodsmith

Jim, as an aside, you have a 15.42:1 reduction ratio motor to wheel. How tall are your wheels?
Just trying to guestimate how it compares with my transmission ratios with my 28" and 31" tall tyres.
Cheers.

Woody, thanks for the nice, polite. correction of my fubar of the total gear reduction. That's the kind of mistake you make when you are old and tired.

I've built myself an excel wheel speed calculator, I would send you a copy but I haven't figured out how to attach an excel file. I can email it if you like.

Jim

[Woodsmith]

Originally Posted by Jimdear2

Woody, thanks for the nice, polite. correction of my fubar of the total gear reduction. That's the kind of mistake you make when you are old and tired.

I've built myself an excel wheel speed calculator, I would send you a copy but I haven't figured out how to attach an excel file. I can email it if you like.

Jim

Not really a correction as the info is there anyway.

I have been working on 11.28:1 in high range and 20.069:1 in low range to get what I think might be a reasonable spread of road speed with the 31" tyres.

I have made up a calculator for gear ratios, and road speed per 1000rpm for any given tyre diameter. Just wondering if we are in the same ball park.
I get 8.2mph per 1000rpm in high and 4.6mph per 1000rpm in low if I use the Lada Tbox and Salisbury axle.