11-04-2016, 01:19 PM
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#2871 (permalink)
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EcoModding Lurker
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Quote:
Originally Posted by MPaulHolmes
encoder-ticks is one of the variables you can set, so it's not a big deal no matter what you pick. I think 256 ticks is plenty. That would turn into 1024 ticks per revolution after the dspic got a hold of it. And with an open collector, wouldn't it take a little time to get pulled up or down? I would err on the side of fewer ticks. I would go with 256 or 512 rather than 1024 or 2048. I'm just thinking about at 10,000 RPM. That's a lot of dang ticks. haha. That's more ticks than my old dog had. Hmm... pwm output based on RPM? I don't think that would be very hard under certain constraints (if it was in the 10KHZ loop). Just as an example, if the RPM was 1Hz, it could be a duty of 10/10000, and 100Hz would be 10000/10000 duty, or whatever. Then, it's just a matter of toggling the port. It's always 5-10 times harder than you would think, but I think this time it would only be 2 times harder. haha
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That is good idea. Since my motor should rotate at more than 10Krpm that would also be a 1:1 divider so whichever chip would transform function to RPM indicator it would have real time signal. Since it has a fixed gear ratio it would also be a simple matter to calculate car speed. Tire size and gear ration etc... That would be done by Arduino DUE chip that would act as CAN bus controller to VCU.
Huh... Paul, since you already have serial interface done, would it be possible to use CAN interface to make dump of all variable parameters in universal format. That way VCU could get correct data to drive dashboard and maybe i wouldnt have to recalculate anything??? Reverse would have to move to a different pin, pin 10 and motor temperature would only be shown on dash. I dont expect anyone would be oblivious to red light on dash when temperature would go across 100°C.
By no means am i fixed to this. Feel free to suggest your solution.
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11-05-2016, 10:10 AM
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#2872 (permalink)
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The Following 2 Users Say Thank You to arber333 For This Useful Post:
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11-05-2016, 02:55 PM
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#2873 (permalink)
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EcoModding Lurker
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Paul, sometime ago you said in mail about resolver
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PHEW! Oh, I got the leaf wiring figured out again.
It goes like this:
COSINE NEGATIVE: YELLOW
COSINE POSITIVE: BLUE
SINE NEGATIVE: BLACK
SINE POSITIVE: RED
EXCITE:POSITIVE (EX): WHITE
EXCITE NEGATIVE (!EX): GREEN
The other 2 wires are the thermistor leads.
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On the R to E board i see also the GND pin on the input. Do you use it at all?
And on the output, how do we use DOS, DIR and LOT pins? Can i just use A, B and I pins besides 5V and GND? I would like to install 5Pin connector.
A
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11-06-2016, 01:17 PM
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#2874 (permalink)
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EcoModding Lurker
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Advice for Newbie
Hello guys, I'm Cooper, I'm 16 and I've started a conversion of an '88 VW Cabbie. My grandfather gave me an older AC motor (15KW / 50KW peak), but we're having a hard time finding a controller. My dad is an EE, so we're thinking of building one of Paul&Sabrina's but wondering how hard it will be to interface it to the motor and how "turnkey" the system will be once built? We're very comfortable with the physical build and soldering, but concerned about the software integration.
Any advice/recommendations? Any help is very much appreciated!
Thanks in advance!
Cooper
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11-06-2016, 03:12 PM
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#2875 (permalink)
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EcoModding Apprentice
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Hello Cooper.
Is your motor old industrial motor? It might not be up to task unless you rewind it. I can tell that rewinding old AC motors can be rewarding and it is not hard or expensive at all. You need an encoder for that motor. What could be better than telling doubting people that you've rewound your motor and even built a controller for it. You could wind it for lower voltages and use safer DC voltages, say 90-150VDC.
I'd say, from reading recent posts, that this AC controller will be as good as P&S DC controller. I've drooled after this controller since this thread got started! Now I'm starting to build mine. I've already rewound some motors and I need another controller for smaller project. No doubt it will be downscaled P&S AC controller.
I can also advise not to buy any Kelly controller at all. They might look tempting (or price tag looks tempting) but they offer you zero support after you get one, promises about performance are way off and they even lie you about what their controllers actually are meant for.
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11-06-2016, 09:22 PM
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#2876 (permalink)
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EcoModding Lurker
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Thanks for getting back so fast! My grandfather says the motor was used by dominion power in some s-10 pickup truck conversions. Dominion power used them in the early 2000's so its not too old. We haven't been able to find too much about the motor but its made by Hughes power control systems and on the motor itself it says it is 60 kw peak. I know that it is oil cooled as well.
It looks like you are converting a similar car. How far have you gotten? what motor/controller are you using? Do you have Batteries? Where did you find them or do you have a plan to get them from somewhere? What voltage are you going for?
Thanks so much for the help!
Cooper
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11-07-2016, 03:03 AM
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#2877 (permalink)
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EcoModding Lurker
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Quote:
Originally Posted by MPaulHolmes
encoder-ticks is one of the variables you can set, so it's not a big deal no matter what you pick. I think 256 ticks is plenty. That would turn into 1024 ticks per revolution after the dspic got a hold of it. And with an open collector, wouldn't it take a little time to get pulled up or down? I would err on the side of fewer ticks. I would go with 256 or 512 rather than 1024 or 2048. I'm just thinking about at 10,000 RPM....
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Well i talked with RLS guys some more and they say their designation is 256cpr not ppr, meaning 8bit encoder is 2x 64ppr pulses with one north marker per revolution. So that comes to a small number does it not? Wouldnt it be better to use 10bit sensor which is a 256PPR per channel and would account to 1024CPR (ticks) together? How does dsPIC operate with those ticks then?
I would like confirmation if i think in a right way? So i dont make a mistake.
tnx
A
Last edited by arber333; 11-07-2016 at 05:00 AM..
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11-07-2016, 10:25 AM
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#2878 (permalink)
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PaulH
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Location: Maricopa, AZ (sort of. Actually outside of town)
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Quote:
Originally Posted by arber333
On the R to E board i see also the GND pin on the input. Do you use it at all?
And on the output, how do we use DOS, DIR and LOT pins? Can i just use A, B and I pins besides 5V and GND? I would like to install 5Pin connector.
A
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Yes, just ignore the ground pin on the resolver side. I dont' think it's necessary. It was in case there was noise, but the lines are so low impedance (like 16 Ohms DC resistance) that I don't think it's worth using a shielded cable, and grounding the drain wire. At least I've never had any trouble getting it to work. Also, ignore the DOS/DIR/LOT pins. Just use a 5 pin connector for +5v, ground, A,B,INDEX.
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11-07-2016, 10:28 AM
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#2879 (permalink)
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PaulH
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
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Quote:
Originally Posted by CoopL
Hello guys, I'm Cooper, I'm 16 and I've started a conversion of an '88 VW Cabbie. My grandfather gave me an older AC motor (15KW / 50KW peak), but we're having a hard time finding a controller. My dad is an EE, so we're thinking of building one of Paul&Sabrina's but wondering how hard it will be to interface it to the motor and how "turnkey" the system will be once built? We're very comfortable with the physical build and soldering, but concerned about the software integration.
Any advice/recommendations? Any help is very much appreciated!
Thanks in advance!
Cooper
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If you can include an encoder, it's a snap getting the motor to work. You can just run an autotuning command so that it automatically finds the rotor time constant as well as the PI constants. Then, you save those values and forget it. It's not a big deal.
Here are the commands:
run-pi-test
run-rotor-test
save
hurray, done! haha
-Paul
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11-07-2016, 11:14 AM
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#2880 (permalink)
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EcoModding Apprentice
Join Date: Oct 2009
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Quote:
Originally Posted by CoopL
Thanks for getting back so fast! My grandfather says the motor was used by dominion power in some s-10 pickup truck conversions. Dominion power used them in the early 2000's so its not too old. We haven't been able to find too much about the motor but its made by Hughes power control systems and on the motor itself it says it is 60 kw peak. I know that it is oil cooled as well.
It looks like you are converting a similar car. How far have you gotten? what motor/controller are you using? Do you have Batteries? Where did you find them or do you have a plan to get them from somewhere? What voltage are you going for?
Thanks so much for the help!
Cooper
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My conversion was finished back in 2010. I drove it 4,5 years and then rust became too big issue. It was DC motor at 144V and of course P&S DC controller. Now I'd like to start similar conversion but with rewound AC motor and P&S controller! 140-160V. For batteries I'd use 18650 cells as they are pretty cheap right now. You should consider finding a wreck Nissan Leaf or Chevy Volt or anything similar for batteries. Disassemble, sell controller, motor and keep batteries. Even if you only bought a battery from wreckage it will be cheaper than getting brand new cells.
Then back to controller topic
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