OSHW TO247 IGBT watercooled laminated half-bridge

Electric Motors and Controllers

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby Arlo1 » Thu Apr 27, 2017 10:37 am

marcos wrote:
3d board2.jpg



IN this picture the trace that comes from the boost transistors on the top right side and wraps around the last igbt on the right side then runs from right to left.
My Leaf motor controller build. http://endless-sphere.com/forums/viewto ... 27#p963227
My YSR build http://www.youtube.com/watch?v=BRo8r5g4NBg
RC and most types of Lithium batteries you MUST know your individual cell voltages charging and discharging.
Don't keep them were you cant afford smoke or fire!
Never above 4.2v never below 2.7v EVER!!!
HI power controller design. Game Changer
User avatar
Arlo1
100 GW
100 GW
 
Posts: 8413
Joined: Sun Apr 26, 2009 10:36 pm
Location: Nanaimo BC Canada

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby marcos » Thu Apr 27, 2017 11:46 am

Arlo1 wrote:IN this picture the trace that comes from the boost transistors on the top right side and wraps around the last igbt on the right side then runs from right to left.

Ah, I see. In theory its awful, it builds up all kind o parasitics. On the other hand, this is a tesla model S inverter, its 300+kw. Look closely at the red board, you can clearly see individual gate resistors, 2 on each gate, and the long copper traces. Those are the gate traces for all those igbts.
https://electrek.files.wordpress.com/20 ... &strip=all

And here you can see that mechanical assembly and copper stackup
https://www.google.com/patents/US20120305283

I try to keep that long trace wide for low resistance unbalance (the individual gate resistors should make that negligible). And I try to keep the inductance at a minimum by making the current loop minimal using the 0.15mm pcb stackup.
marcos
100 W
100 W
 
Posts: 119
Joined: Sat Nov 19, 2016 11:38 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby helno » Thu Apr 27, 2017 12:44 pm

Really nice looking design. Can't wait to see how it performs after manufacturing.

How much do you estimate it will weigh? I am looking for a 400 volt capable esc but only need around 100 A for a few minutes and 30-60 A continuous.
helno
100 mW
100 mW
 
Posts: 36
Joined: Mon Apr 10, 2017 2:23 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby marcos » Fri Apr 28, 2017 8:23 pm

It should be fairly light. Its hard to tell the weight until the assembly is ready, I'd guess 3kg, just to say a number.

You're asking for a 40kw inverter, that is no small feat, keep in mind that in a "few minutes" you might already reach steady state, so plenty of cooling should be considered.
marcos
100 W
100 W
 
Posts: 119
Joined: Sat Nov 19, 2016 11:38 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby fechter » Fri Apr 28, 2017 9:46 pm

Great project. I like the pictures of the Tesla inverter. You can bet they did their homework designing that one. I always like to copy proven features.
"One test is worth a thousand opinions"
User avatar
fechter
100 GW
100 GW
 
Posts: 11408
Joined: Sun Dec 31, 2006 3:23 pm
Location: California Bay Area, USA

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby helno » Sun Apr 30, 2017 2:47 pm

marcos wrote:plenty of cooling should be considered.


It would be for an aircraft. So cooling air should not be a problem. I would prefer to avoid liquid cooling to get rid of the pump as a failure point.
helno
100 mW
100 mW
 
Posts: 36
Joined: Mon Apr 10, 2017 2:23 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby HighHopes » Sat May 06, 2017 6:15 pm

about your link to tesla invverter. i have seen other tear downs to the inverter board and i'm impressed they can get that much current through there PCB. it doesn't even look like very thick copper... 2oz? impossible... yet that's what it looks like
User avatar
HighHopes
10 kW
10 kW
 
Posts: 839
Joined: Thu Mar 28, 2013 6:25 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby marcos » Sat May 06, 2017 7:02 pm

HighHopes wrote:about your link to tesla invverter. i have seen other tear downs to the inverter board and i'm impressed they can get that much current through there PCB. it doesn't even look like very thick copper... 2oz? impossible... yet that's what it looks like

That red pcb does't carry much current, it only drives the gates. Its connected to the sources and gates, no connection to the drains.

Below the red pcb there are copper sheets welded to the TO247 leads. Check the first image of the patent link above, it makes it much more clear.
And also this one:
https://patentimages.storage.googleapis ... D00006.png
Last edited by marcos on Sat May 06, 2017 7:31 pm, edited 1 time in total. View post history.
marcos
100 W
100 W
 
Posts: 119
Joined: Sat Nov 19, 2016 11:38 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby HighHopes » Mon May 08, 2017 7:28 pm

copper sheets, sure, but they aignt using copper sheets in this one

Image
User avatar
HighHopes
10 kW
10 kW
 
Posts: 839
Joined: Thu Mar 28, 2013 6:25 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby marcos » Tue May 09, 2017 3:13 pm

Yes, thats an old tesla roadster half bridge. Its around 10 years old by now. Its suprising they rated that drivetrain at 180kw.
I recall doing the math of copper thickness and pcb size for that board, and it made sense at some point.
The thing I never figured out is how to get the current out of that pcb. I don't know which kind of connection they used.
Anyway, I don't like that approach, pcbs are not the right thing for that power level.
marcos
100 W
100 W
 
Posts: 119
Joined: Sat Nov 19, 2016 11:38 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby bj001 » Tue May 09, 2017 8:11 pm

what's with the nuts almost shorting the drains of the fets?
p channel fet on the top?
I'm missing something...

Sent from my SM-G920I using Tapatalk
bj001
1 mW
1 mW
 
Posts: 11
Joined: Fri Jul 03, 2015 7:50 am

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby marcos » Tue May 09, 2017 9:36 pm

Those are IGBTs, and I don't remember what are those nuts for. On the other side there are several dc link+ snubber caps.
Top layer carries dc+, bottom layer is dc-. And both layers carry phase in the middle. Its a laminated bus, good stuff.
marcos
100 W
100 W
 
Posts: 119
Joined: Sat Nov 19, 2016 11:38 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby HighHopes » Wed May 10, 2017 7:39 pm

glad we feel the same way. didn't tesla put all their patents up for open use? perhaps they don't mind if we copy...

i know of a battlebots builder that uses discretes sintered onto copper sheets. lab tests show impressive results. there's definitely something worth investigating here

or

just drop in a large module. lower overall inverter volume, more robust for same power level. more expensive though but its not a whole lot more
User avatar
HighHopes
10 kW
10 kW
 
Posts: 839
Joined: Thu Mar 28, 2013 6:25 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby marcos » Sat Jul 08, 2017 10:27 am

Now that I sorted out the controller for this setup I should get back to this. Microcontroller stuff is fun and all, but I already know how to build those things, and gate driver design is a new challenge for me. Not much free time though.

So next time I get a moment of peace on this computer I'll start copying the right side of this board to the left side so bottom and top gate driver have the exact same layout. I didn't test the power supply, but I'm on a winning streak with power supplies so I'll just send it to mfg and give it a try :-)

The day that I'll be stuck without a couple of rogowski probes is coming... I'm very aware of that. At least having full control of the controller inner workings allows for some deeper probing and debugging using firmware tools.
marcos
100 W
100 W
 
Posts: 119
Joined: Sat Nov 19, 2016 11:38 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby marcos » Sat Jul 08, 2017 10:30 am

HighHopes wrote:or just drop in a large module. lower overall inverter volume, more robust for same power level. more expensive though but its not a whole lot more

Heard you and the module approach became stage I. Now stage II is getting the actual thing done :-)
marcos
100 W
100 W
 
Posts: 119
Joined: Sat Nov 19, 2016 11:38 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby marcos » Tue Jul 11, 2017 2:02 pm

Quick update, its looking nice and symmetric

IGBT_board.jpg

On the control side I was using 3.3v but now its 5v for better noise immunity, and placed a bigger regulator so it doesn't heat up that much.

It needs a connector on the right for the current sensor and a way to measure temperature.

Here is an overlay so its clearer whats going on
IGBT_board overlay.jpg

The green stuff is a tesla patent, by default it switches slow and safe -no overshoots- but under the right conditions you can make it switch off harder for increased efficiency (and higher overshoots).
marcos
100 W
100 W
 
Posts: 119
Joined: Sat Nov 19, 2016 11:38 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby HighHopes » Wed Jul 12, 2017 9:00 pm

what i remember is that tesla controls the gate voltage to manage switch time which influences voltage transients. if that's the one you're talking about, i don't know how they can patent this as its an idea been around for ages. it was called dynamic gate driver back in the day, almost 20 years ago. i've seen all sorts of different incarnations over the years, some work, most don't. good luck! glad to see you're still working on this inverter, came a long way.
User avatar
HighHopes
10 kW
10 kW
 
Posts: 839
Joined: Thu Mar 28, 2013 6:25 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby marcos » Wed Jul 12, 2017 11:18 pm

Maybe the patent describes a higher level something. I recall they use a particular feedback (or was it feedforward) overshoot management loop, and they happened to describe how the actual hardware was laid out, and with a couple of pictures I may have figured it out. Or maybe not, we'll find out way after I test the basic stuff.

Someone posted something about being silly about not seeing the desat circuit, and his signature linked to a good thread about a diy gate driver that I didn't read before. Spent quite some time today reading the complete thread on the phone and something caught my attention. A dude found that his desat does not work at high temperature because this diode sinks all the desat blanking current as reverse leakage current.
Image
In a sense, that would affect me too.
reverse current desat schottky.png


It looks like at 100°C half the current coming from the internal 500uA current suply is sunk in the diode, so the blanking time last twice the time if I'm reading this correctly.

In the case of the avago gate driver that has a 250uA current for the blanking time constant, since the diode sinks 250uA it gets stuck on that blanking time and you get no desat protection. My TI gate driver would just have the desat disabled for 4us instead of 2us, for example, and completely disabled at near 120°C.

This is not going to reach such high temperatures. 100°C or even 85°C in the gate driver pcb is way too much for my taste, there are electrolytic caps on board that should live a long, cool life. But hey, this came from seemingly nowhere and it could have hit me big time if I had a poorly chosen schottky diode.

So thanks to the dude who pointed me to that thread. Schottky reverse currents are something to keep in mind.
Attachments
danger schottky.png
(150.06 KiB) Not downloaded yet
Last edited by marcos on Thu Jul 13, 2017 12:10 pm, edited 1 time in total. View post history.
marcos
100 W
100 W
 
Posts: 119
Joined: Sat Nov 19, 2016 11:38 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby HighHopes » Fri Jul 14, 2017 6:44 pm

good point. you probably don't need that diode at all if have low voltage transients anyway. i built many high power gate drivers without it.
User avatar
HighHopes
10 kW
10 kW
 
Posts: 839
Joined: Thu Mar 28, 2013 6:25 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby marcos » Fri Jul 14, 2017 8:18 pm

HighHopes wrote:good point. you probably don't need that diode at all if have low voltage transients anyway. i built many high power gate drivers without it.

In that case I'll keep the footprint but change the part# for one that I can use with confidence at 100°C
marcos
100 W
100 W
 
Posts: 119
Joined: Sat Nov 19, 2016 11:38 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby marcos » Mon Jul 17, 2017 12:27 pm

Diode changed for one with less leakage.

The gate driver pcb looks ready to me, its $85 for a set of 5 boards in seeedstudio. A bit higher if I choose 2 Oz copper. But before that I need to continue with the copper sheets, maybe next week.

3d board3.jpg
3d board3.jpg (70.3 KiB) Viewed 230 times
marcos
100 W
100 W
 
Posts: 119
Joined: Sat Nov 19, 2016 11:38 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby SplinterOz » Mon Jul 17, 2017 4:53 pm

Looking really good.
SplinterOz
In the Capital of Australia
http://rgelectric.wordpress.com
User avatar
SplinterOz
10 kW
10 kW
 
Posts: 529
Joined: Wed Apr 21, 2010 4:29 am
Location: Canberra

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby SjwNz » Mon Jul 17, 2017 7:39 pm

Someone posted something about being silly about not seeing the desat circuit, and his signature linked to a good thread about a diy gate driver that I didn't read before. Spent quite some time today reading the complete thread on the phone and something caught my attention.


That may of been me ? I posted about not seeing desat in your Sch on page 1, but then I clicked on the link and saw your did have desat so deleted the post
as I felt a bit silly. I think it was Futterama, he did some tests and was talking about the leakage current through the Zener/schottky at high temperatures on my thread.
With the gate drive I was using (ACPL-333J) the desat current was only 250uA, but the newer version of that gate driver chip (ACPL-337) is now using 1mA.
My 6fet controller - viewtopic.php?f=30&t=61937
User avatar
SjwNz
100 W
100 W
 
Posts: 145
Joined: Tue Jul 19, 2011 4:50 am
Location: Hamilton, New Zealand

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby marcos » Mon Jul 17, 2017 10:18 pm

Yeah, it was you but with the post deleted I couldn't remember your name or the thread name :P

So thanks sjwnz, it was a good read. I don't think there is a better place on the internet to get involved with these subjects.
marcos
100 W
100 W
 
Posts: 119
Joined: Sat Nov 19, 2016 11:38 pm

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Postby HighHopes » Fri Jul 28, 2017 5:44 pm

did u use seeeds to fab the board too? 1oz is good pricing, but 2oz is more than 10x?
User avatar
HighHopes
10 kW
10 kW
 
Posts: 839
Joined: Thu Mar 28, 2013 6:25 pm

PreviousNext

Return to Motor Technology

Who is online

Users browsing this forum: No registered users and 12 guests