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general advise on invertors to drive a Leaf motor
Posted: Sun Feb 02, 2020 11:29 am
by zippy500
Like to know what other people would chose ,
I have a Leaf em57 motor, the original invertor that came with it is broken/faulty.
I have half built a power stage (igbts, caps, bus bars) some time ago, no control board ( to use Pauls original AC control board)
I keep changing my mind now, should i carry on with my build and fit a rev3 board ?
I am now looking at Toyota Gen3 inverter with EVbmw dropin board, now the cost of boards has come down?
How would you drive a leaf motor ?
I am open to other options
Thanks
Re: general advise on invertors to drive a Leaf motor
Posted: Sun Feb 09, 2020 11:54 am
by johu
I'd try to diagnose the issue with the original inverter or else find an inverter on the interweb. It integrates so nicely that it's hard to beat with something homebrew.
- IGBTs good? - if not probably hard to replace
- Driver board good? If not, can you fix it?
- Logic board good? If not, replace by a drop-in board
Re: general advise on invertors to drive a Leaf motor
Posted: Sun Feb 09, 2020 12:24 pm
by arber333
Prius Gen3 would give 300A on the motor side. No matter the 600A rating of the urrent sensors i expect it to be rated for a surge.
If you can get Lexus inverter i expect the story would change.
Volt inverter we allready tested with EM61 motor and it works good. I am intending to paralell both IGBT stages for really fast starts or 1/4 mile racing.
I pretty much will not build another power section again. It has cost me too much. Even from schratch i cant build good PS for less than 800€ and then comes the control part. Whereas perfectly good inverters are to be found in the scrapyards for 200€ or 300€ with all the protection incorporated.
Re: general advise on invertors to drive a Leaf motor
Posted: Sun Feb 09, 2020 1:43 pm
by zippy500
johu wrote: ↑Sun Feb 09, 2020 11:54 am
I'd try to diagnose the issue with the original inverter or else find an inverter on the interweb. It integrates so nicely that it's hard to beat with something homebrew.
I took apart the leaf inverter board that came with the motor, all three IGBTs where physically broken under the circuit board, apparently the car was used for crash testing, motor is still ok.
so the leaf invertors are matched to the motor for the angle offset,
Johu, If I buy anther leaf invertor can I assign the offset on your V3 board/
I like the functionality that you have created with your board
arber333 wrote: ↑Sun Feb 09, 2020 12:24 pm
I pretty much will not build another power section again. It has cost me too much. Even from schratch i cant build good PS for less than 800€ and then comes the control part. Whereas perfectly good inverters are to be found in the scrapyards for 200€ or 300€ with all the protection incorporated.
I pretty much have the power stage built and mounted on a ali plate, doesn't Johu board have protection incorporated.
Do you think it is a bad idea to carry on with my own setup ? do you think I will encounter many problems , Im not a EE
Re: general advise on invertors to drive a Leaf motor
Posted: Sun Feb 09, 2020 2:13 pm
by arber333
zippy500 wrote: ↑Sun Feb 09, 2020 1:43 pm
I pretty much have the power stage built and mounted on a ali plate, doesn't Johu board have protection incorporated.
Nope. And i think you dont use snubbers? I am not sure you wouldnt get high spikes on large Amp demand.
I think more work should be done about protected driver interface based on available commercial driver boards
viewtopic.php?f=2&t=296
or there was talk here about some other driver board, i cant remember which... it may come to me.
I am attaching a rev. 3 board which i am not developing further. It has 15V regulator onboard so it can be used with 3x Skyper drivers directly. Feel free to develop it or use it to remodel it to other boards.
Re: general advise on invertors to drive a Leaf motor
Posted: Sun Feb 09, 2020 2:33 pm
by zippy500
Many Thanks....Im even more confused now
Will the gen3 or GH450 drive the leaf motor,
I would have to buy the inverter and the board i suppose.
Re: general advise on invertors to drive a Leaf motor
Posted: Sun Feb 09, 2020 5:20 pm
by johu
If you use the "johu" board you will recalibrate the angle offset anyway. Like so:
https://openinverter.org/wiki/Using_FOC_Software
There is overcurrent protection on the johu board also in form of an analog current comparator. Should current become too high it will shut down your power stage. It has worked flawlessly for me in 6 years but I'm only pushing my 400A modules to 200A. Folks who go closer to the limit apparently saw some magic smoke.
What Arber is saying, if you use protected gate drivers you will have another layer of protection as opposed to the driver boards that come with the V3 kit:
https://openinverter.org/shop/index.php ... duct_id=60
Less confused now?
Re: general advise on invertors to drive a Leaf motor
Posted: Sun Feb 09, 2020 6:26 pm
by zippy500
OK, Thanks
I have already purchased your powerstage kit already , just waiting on the post. Think I will just stick with this now.
arber333 wrote: ↑Sun Feb 09, 2020 2:13 pm
Nope. And i think you dont use snubbers? I am not sure you wouldnt get high spikes on large Amp demand.
Is the snubber just anther capacitor, wont the film caps do that job.
Can you give a link of a snubber to use then.
Does it fit accross the HV bus rail too ?
Re: general advise on invertors to drive a Leaf motor
Posted: Sun Feb 09, 2020 7:45 pm
by arber333
zippy500 wrote: ↑Sun Feb 09, 2020 6:26 pm
Is the snubber just anther capacitor, wont the film caps do that job.
Can you give a link of a snubber to use then.
Does it fit accross the HV bus rail too ?
I use exactly this one and i soldered its contacts onto a flat copper/brass section to better clamp it DIRECTLY over IGBT output contacts.
https://www.ebay.com/itm/2-2uF-1600V-WI ... 1544535826
There are various forms of snubbers, so you can browse to get 3x you can fit to your power stage.
You can try running your motor without them and slowly up the amps on startoff. There they are most usefull.
You will see how much your film caps absorb current spikes. Snubber capacitance RoT is 1uF per 100A after initial 100A or so. So 2uF for 300A PS and 3uF for 400A PS.
One added protection that comes with desat drivers is shoothrough protection. In case your upper transistor should have problems to close fast (due to current spikes) your driver will protect the lower transistor by shutting PWM down.
What is your target Amp rating?
Re: general advise on invertors to drive a Leaf motor
Posted: Sun Feb 09, 2020 8:13 pm
by zippy500
Ok, just one step back. (this is all new to me)
( been watching some youtube) A snubber has a resistor and capacitor built into it to catch the high voltage spikes
so..how does it connect on the circuit ?
Is it IGBT output ?, where does the other leg connect to ? ( a picture is a thousand words

)
Do I need Three then, one for each IGBT ?
Thanks