Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control - Page 303 - Fuel Economy, Hypermiling, EcoModding News and Forum

HaroldinCR · 03-19-2017, 01:26 PM

Freebeard
There is no cooling fan. These are water cooled. I'm thinking natural convection circulation.

thingstodo · 03-19-2017, 02:16 PM

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Originally Posted by MPaulHolmes

Yes I'm definitely interested in figuring out the CAN codes.

Excellent - step one complete!

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I'm sure I'll need help, but I could use the AC board to capture some can data, and then stream it over serial.

Everyone needs help. Some of us just don't know that ... or accept that .. sometimes

As far as I understand, EVTV had to use the GEVCU to timestamp and buffer the data, since it IS order dependant and the Tesla uses much of the bandwidth available. A 115K serial link may keep up to the 250K or 500K CANbus if it is not saturated with data. 250K and 500K are common for CANbus. 125K does not seem to be used. I have heard of a higher rate - 1 MB or 2MB? I have not seen anything that uses the higher data rate, either.

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I've got CAN working, and have tested it on a BMS I did a couple years ago based on Fran Sabolich's suggestions. I used it to send 48 battery voltages over CAN to a charger, and it worked great. The nice thing about it was, you could just blast your messages willy nilly, not caring what other CAN nodes were doing, and the people (charger) who were supposed to get the message just got the message, and the people (other battery groups) who were supposed to ignore it, ignored it!

I'm sure that I would have remembered if I had seen this posted elsewhere. Was it posted anywhere on ECOMODDER? Good job, in any case.

Blasting out the info and letting any node that is interested in the data use it for whatever they like ... that's one of the big plus's on CANbus. The big negative is that in order to consume the data, you need a map - what does each bit or byte mean, and what is the scaling? This is fine if you did both sides (data source and data consumer), or you have the documentation. Not so great if you are reverse engineering .. say the Leaf .. and don't even have a starting point

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So, if I added a CAN node to the group, I could just have a mask that says I should receive everything, and I just sit back and listen?

That's how I understand it. Mask matches all, let me know when ANYTHING comes in. I'm not sure if timing is a big deal on the LEAF bus ... but I expect that it may be. If just playing back the captured data as fast as you can (with the ECU disconnected from the bus) does not power up the car and do stuff, it may need to be timestamped before being stored (relative to start of capture should be OK) so that you can play it back with the correct delays between the messages

The other concern is missing a message that was important. If it does not fit through the 115K (or whatever you are using) serial link it may be dropped but you may not know that.

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And I should leave the spot on the board for the 120Ohm resistor unpopulated, because those 120Ohm resistors are probably somewhere else in the car already (between CANH and CANL)?

Perhaps a 2 pin connector? For bench testing you can add the resistor but in the car I wold not expect the controller to be one end of the bus?

The CANbus is used by Rockwell (with 2 more network layers added, they call it Devicenet) so I have some experience with that. If you are under 10 feet, termination resistors are sort of optional. You can make it work on your bench with cat5 network cable, no terminators, and the ugliest splices you'd ever want to see.

In the environment of an Motor Control Center (MCC) room, with AC and DC controllers running nearby, UPS systems on the same AC supply, etc you need the correct cabling, terminators at the ends and only 1 at each end, the drop cables and taps need to be properly sealed to keep out moisture and other gunk.

In my experience, the Devicenet controller works better in the center of the bus. It still works on one end of the bus, but unscheduled throughput is lower. Like saving the configuration of a VFD. That is no likely a factor in a car .. but who knows?

Another post that is too darned long .. sigh! ..

thingstodo · 03-19-2017, 02:23 PM

Quote:

Originally Posted by MPaulHolmes

Josiah is going to help me do a nice video of the whole setup. He's been practicing his lighting, and has been acting as my apprentice lately.

I think I missed that part of the post

It's good to hear that you are passing on your knowledge and experience to the next generation!

freebeard · 03-19-2017, 03:03 PM

HaroldinCR — It's the opposite problem. It's the stinky gas engine that is air cooled. The fan attaches to the back side of the generator/alternator.

The other thing fascinating about CANbus is the implementation of dominant and recessive messages. I'll bet thingstodo can explain it better than me.

BTW my son now works for Rockwell, after Thales wanted him to relocate from Seattle to Edison, NJ.

thingstodo · 03-19-2017, 04:56 PM

Quote:

Originally Posted by freebeard

BTW my son now works for Rockwell, after Thales wanted him to relocate from Seattle to Edison, NJ.

Really? Rockwell is a large company - which product area does he work in?

freebeard · 03-19-2017, 05:55 PM

I'm not sure. He was on contract until the first of the year, and we haven't had much contact. Something to do with QA, aircraft instrumentation or flight controls.

Can you describe how CANbus deals with collisions by making messages dominant and recessive? I know EVTV did.

MPaulHolmes · 03-20-2017, 03:16 AM

Harold, I'd love to learn more about that motor. Post away (here or in a new thread).

thingstodo, I never posted anything much about the BMS. A microcontroller powered by the 12v system supply monitoring 'n' battery voltages. It monitors the 'n' batteries by receiving the voltages from little attiny25 microcontrollers that are powered by each cell. They send the voltage by a sort of morse code across optocouplers. The attinys are only powered when their cell circuit is enabled, so if the 12v power is off, there's zero draw from the cells. One neat trick was, for each attiny25 to measure its cell's voltage, it would just measure a 1.25v reference on the A/D channel. Then, from that you can infer the cell's voltage. For example, if you read 1023, that would mean the cell's voltage was 1.25v. But if you read 512, that would mean the cell's voltage was 2.5v, etc...

We fly out tomorrow! yay. haha My brother in law is getting married.

HaroldinCR · 03-20-2017, 08:24 AM

Paul, found the controller location in the car, inside the battery case. Battery is over 5 years old so probably NG or close to it, SOOOOOOOOOOO, I'm gonna try to just buy the controller.

You possibly up for a hack job ??

Gotta unload some of my 2015 Leaf modules to free up some dough.

freebeard, RPM's of the altermotor get to 30,000 when driven by the stinko engine. Altermotor has a 175A fuse and uses a 115V battery. Possibly 60 HP ??

MPaulHolmes · 03-20-2017, 03:09 PM

Possibly yes! No promises, but I'll see. Is there a practical way to get a basic position sensing on it, even if it's just 1 or 2 or 3 or 4 pulses per revolution?

HaroldinCR · 03-20-2017, 04:10 PM

These have an encoder or resolver with 10 poles. The stator is 72 poles and the rotor is 56 poles. I'm going to try to get the controller and cable from a wrecked car. That would give the whole system, except for hacking, maybe. Might be a month or so, before I can work out a deal.

One option might be for you to buy the motor in Wa/Or, and I send Paypal to you cover it, while I work on the rest. That would save a bunch on shipping the motor, if you carry one back home from your day job. Just don't pay more than $100.00 and don't accept the fake core replacement scam.

We are looking between 2012 and 2015 year models.

I'm looking for a peppy Motorcycle conversion.