Go Back   EcoModder Forum > EcoModding > Fossil Fuel Free > Open ReVolt: open source DC motor controller
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 01-12-2012, 12:41 PM   #5421 (permalink)
EcoModding Apprentice
 
Join Date: Mar 2011
Location: alaska
Posts: 141
Thanks: 10
Thanked 32 Times in 18 Posts
it's going to be a hybrid of your logic board, adam's power stage, and my bus bars/enclosure. i'll let you know!

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 01-12-2012, 12:52 PM   #5422 (permalink)
EV test pilot
 
bennelson's Avatar
 
Join Date: Jan 2008
Location: Oconomowoc, WI, USA
Posts: 4,435

Electric Cycle - '81 Kawasaki KZ440
90 day: 334.6 mpg (US)

S10 - '95 Chevy S10
90 day: 30.48 mpg (US)

Electro-Metro - '96 Ben Nelson's "Electro-Metro"
90 day: 129.81 mpg (US)

The Wife's Car - Plug-in Prius - '04 Toyota Prius
90 day: 78.16 mpg (US)
Thanks: 17
Thanked 657 Times in 383 Posts
I really liked Paul's logic board on the 1000 Amp controller. It was nicely laid out, clean, and included an automated pre-charge right on there.

It still worked great, even after I totally blew the power stage.
__________________


300mpg.org Learn how to BUILD YOUR OWN ELECTRIC CAR CHEAP
My YouTube Videos

Last edited by bennelson; 01-12-2012 at 02:24 PM.. Reason: possesive type
  Reply With Quote
Old 01-12-2012, 01:10 PM   #5423 (permalink)
ReVolt Enthusiast
 
Join Date: Jun 2009
Location: Michigan, USA
Posts: 239
Thanks: 98
Thanked 41 Times in 36 Posts
Quote:
Originally Posted by DJBecker View Post
Our controller has software-only overcurrent control, which means we are much more careful about it. (Plus we had two batches of counterfeit IR MOSFETs which caused us to rewrite the limit code a few times.)

We check just before setting the PWM register, and skip the next PWM cycle (set the width to 0) whenever the current is above the limit.
This is a separate, explicit check that is not part the normal control loop. That way changing the control loop constants won't accidentally defeat the current limit.

We hit the current limit frequently, and can tell immediately by the hissing noise from the motor that results.

We also clamp the MOSFET to the live bus bar. We haven't seen any gate drive issues from that configuration, even with one DC-DC converter and a single gate driver driving all of the MOSFETs. It may be because we run a twisted pair from the gate driver board to each MOSFET. The actual connection to the MOSFET pins is made with a tiny (0.5"x0.325") circuit board that has a 10R gate resistor and 1R0 source resistor.

That reminds me, you might consider adding a gate drive LED for debugging.
Our gate connection circuit board has pads for a TVS (SMBJ12A), and a LED+resistor (both 0805 size). The LED is only installed on the end MOSFET board. Even pointed the wrong way, the reflected glow lets us know that the gate driver is working during tests. In retrospect, we should have put LEDs on the gate driver board itself, but they had already been made.
DJBecker,

Thank you for your shared knowledge.

Have you posted any Photos or Specs of your controller and driver PCB on this forum ??? If not could you ??? Clamp your MOSFET's to the bus bars for testing or assembly ???

Thanks,

-Mark
  Reply With Quote
Old 01-12-2012, 01:38 PM   #5424 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,829

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,366
Thanked 1,115 Times in 730 Posts
Quote:
Originally Posted by bennelson View Post
I really liked Paul'f logic board on the 1000 Amp controller. It was nicely laid out, clean, and included an automated pre-charge right on there.

It still worked great, even after I totally blew the power stage.
There really is absolutely no connection between the power stage and control stage other than the control stage sending light across the void to the power stage (by LEDs inside the optocoupler) to tell it what to do. If something fails, the little beams of light to the power stage just don't do anything anymore. I don't think there's any possible way for the control board to be damaged by a naughty power stage.
__________________
kits and boards
  Reply With Quote
Old 01-12-2012, 07:06 PM   #5425 (permalink)
EcoModding Apprentice
 
Join Date: Nov 2010
Location: Annapolis
Posts: 159
Thanks: 0
Thanked 29 Times in 24 Posts
Quote:
Originally Posted by sawickm View Post
DJBecker,

Thank you for your shared knowledge.

Have you posted any Photos or Specs of your controller and driver PCB on this forum ??? If not could you ??? Clamp your MOSFET's to the bus bars for testing or assembly ???
By "clamp" I mean using spring heat sink clips e.g. MAXCLIP08G. We clean the back of the MOSFET, polish the bus bar, spread a little anti-oxidant grease, and screw down using a hole drilled and tapped into the bus bar.

Each MOSFET has the tiny gate drive connection board slid onto its leads, then the source pin is soldered to a tinned copper strip that makes the connection to the adjacent bus bar.

I think I've posted the board outline of the gate driver and STM32 controller boards before, but I'll do it again this evening if there is interest.

Update: Here is the post with the gate driver board.

http://ecomodder.com/forum/showthrea...tml#post238466

Last edited by DJBecker; 01-12-2012 at 08:07 PM..
  Reply With Quote
Old 01-13-2012, 08:08 AM   #5426 (permalink)
ReVolt Enthusiast
 
Join Date: Jun 2009
Location: Michigan, USA
Posts: 239
Thanks: 98
Thanked 41 Times in 36 Posts
Quote:
Originally Posted by DJBecker View Post
By "clamp" I mean using spring heat sink clips e.g. MAXCLIP08G. We clean the back of the MOSFET, polish the bus bar, spread a little anti-oxidant grease, and screw down using a hole drilled and tapped into the bus bar.
Ok, you are using the same technique that Paul uses on his MOSFET/Busbar assembly.

Quote:
Each MOSFET has the tiny gate drive connection board slid onto its leads, then the source pin is soldered to a tinned copper strip that makes the connection to the adjacent bus bar.
Do you have to worry about vibration cracking the solder joint from the soldered source pin - copper strip - busbar connection? I might not be visualizing that correctly?

Quote:
I think I've posted the board outline of the gate driver and STM32 controller boards before, but I'll do it again this evening if there is interest.
You did post info on your gate driver, but I don't remember seeing your STM32 controller PCB. I would be interested in seeing your controller PCB, and your assembled unit too.

Thanks,

-Mark
  Reply With Quote
Old 01-13-2012, 07:29 PM   #5427 (permalink)
EcoModding Apprentice
 
Join Date: Nov 2010
Location: Annapolis
Posts: 159
Thanks: 0
Thanked 29 Times in 24 Posts
Our motor control board is based on a STM32 processor in a 64 pin package. The lower section is has a 5V regulator and CAN transceiver. It's isolated from the upper section with a DC-DC converter and a Si8421 2 channel digital isolator.
Attached Thumbnails
Click image for larger version

Name:	STM32-motor-control.png
Views:	148
Size:	35.7 KB
ID:	10051  
  Reply With Quote
The Following User Says Thank You to DJBecker For This Useful Post:
sawickm (01-13-2012)
Old 01-13-2012, 07:58 PM   #5428 (permalink)
AC-DC enthusiast
 
mrbigh's Avatar
 
Join Date: Nov 2009
Location: Long Island, NY
Posts: 282

Dual-PWR PHEV - '04 Toyota Prius

Kopper - '79 Bradley Bradley GT-II
Thanks: 122
Thanked 52 Times in 36 Posts
Quote:
Originally Posted by DJBecker View Post
Our motor control board is based on a STM32 processor in a 64 pin package. The lower section is has a 5V regulator and CAN transceiver. It's isolated from the upper section with a DC-DC converter and a Si8421 2 channel digital isolator.
WOW, it's really tiny....
__________________
. .. .. . .......
Prius Absolutum Dominium . ..........KOPPER
PHEV conversion since Dec 2006.. . .... .Future EV
. . . . . . . .CALCars # 27. . . . . . . . . . ..on the works now !!
. . . . . . . . . . . . . . . . .. . ........
  Reply With Quote
Old 01-13-2012, 09:35 PM   #5429 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,829

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,366
Thanked 1,115 Times in 730 Posts
Man that is beautiful!

I sent in 2 files for new control and driver boards today. Adam had told me about the $33 for a single board thing they do, so I'm trying that. The power board is just going to have to wait until later, because it's friggen expensive to get the setup fee paid for it. So, this one will use the left over power board. I still want to try a high side power board, and I finished making one on the computer, but I think Joe's idea of just using what's already available makes a lot of sense.

On the new board, it has the "watchdog for the watchdog" feature. haha. You know, disable the mosfet driver if the microcontroller freezes up for more than 0.001 seconds. That circuit is tested and working. Also, it has adjustable hardware overcurrent trip point from about 50 amps up to around 1200 amps. I'm also going to change the code to allow for any max current you want. And for now, if the overcurrent trip point happens, it's going to flag a fault so that you have to lift the foot all the way off the throttle to clear it. Eventually the hardware overcurrent should never come on anyway.

I'm using 6 shielded twisted pairs to go to each pair of mosfets on the driver board from the control board. Every path is as short as the packages I'm using will allow. Each mosfet has its own driver. The distance from mosfet driver output to mosfet leg is only the length of the body of the gate resistor. It can't be shorter with through hole parts.

6 isolated supplies. Unnecessary? Yes! hahaha. But I can use the driver boards unchanged in an AC controller too. Or a high side controller, or brushless DC controller. I also did a version that uses negative voltage on turnoff in case you want to use TO-247 package IGBTs instead, or just want the turn on and turn off of the mosfets to be the same.



I did some rewinding experiments with the line filters. They are VERY rewindable. Removing 5 wraps on the primary changed the result from 12v in, 4 supplies of 10.5v out, to 12v in, 4 supplies of 12.4v out. They agreed to +/- 0.005v.

I"m also going to change the software to allow Ben to have slower ramp up. Like as low as 62.5 amps per second if you floor it, all the way up to thousands of amps per second from flooring it. I still don't get why Ben's controller was so sensitive to the throttle though.
__________________
kits and boards
  Reply With Quote
Old 01-13-2012, 11:19 PM   #5430 (permalink)
EcoModding Apprentice
 
Join Date: Nov 2010
Location: Annapolis
Posts: 159
Thanks: 0
Thanked 29 Times in 24 Posts
Quote:
Originally Posted by mrbigh View Post
WOW, it's really tiny....
It's 1.5" by 1.75". There is no wasted space, and it doesn't cost a lot to make.

That's our May 2011 board. We've learned a bit and improved it since then, but there hasn't been a motivation to have new boards made.

We spent quite a bit of time on the layout and made a few compromises to keep all signals on the top layer. The bottom layer is entirely a ground plane.

The left side is the "quiet side" with 8 analog inputs. The top three have resistor dividers for higher voltage signals.

The right side has four outputs, driven by two dual MOSFETs in SO-8 packages. The MOSFETs are logic level drive and are rated at 9.1 amps per channel.

Each input and output has the same three pin layout. Pin 1 (always on the outer edge) is a ground, pin 2 power and pin 3 the signal. Six of the analog inputs have 3.3V power (for temperature sensors and throttle), with the bottom two have 5V power for the current sensors. All of the MOSFET-driven outputs have 5V power.

Since the ADC has a 3.3V maximum input, we orient the current sensors so that increasing current drops the output voltage: zero current has a 2.5V output dropping to about 1.0V at maximum current.

The four pin connections in the middle are the motor PWM output (ground, +5V, and both low and high side signals) and a SWD program/debug header. We program using a ST-Discovery development board which is well under $20.

The motor controller is voltage isolated from the chassis ground, and it uses an isolated gate driver. That gives us the option of changing it to be traction voltage referenced, or just leave it fully isolated for safety.

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control MPaulHolmes Fossil Fuel Free 3465 05-17-2020 03:46 PM
Paul & Sabrina's Cheap EV Conversion MPaulHolmes Fossil Fuel Free 542 11-12-2016 09:09 PM
Three Dirt Cheap DIY Electric Cars - Part 5 SVOboy EcoModder Blog Discussion 0 12-12-2008 04:10 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com