Paul & Sabrina's cheap DIY 144v motor controller

[SEBART PL]

Originally Posted by jyanof

There isn't a software parameter that affects inductive voltage spikes.

speaking of capacitors, I don't see any in your picture... are they just hidden in the picture?

My capacitors are the same as originall coguar in the picture top left green and black tape conected by wieres with B- and B+ with power board.

Coul you tell me more about snubber, like an RC snubber what parametrs I could try?

My problem at the moment is that controler works with 100A battery limits when I have incresed current to 200A mosfets blown up and get short circuit
I gave the same time production line mosfets but :
- maybe I need compare the gates capacitance more carefully acording to time of open mybe I can build special tool to check speeds of mosfets?

-or maybe it is something wrong with control board or software parametrs ???
my vehicle is 3300 lb 88V and
motor 13,5 kW series 200Amps; 3300lb weight, 6kp ki30 tposgain17 t pwm gain9 c-rr 6

[jyanof]

Originally Posted by SEBART PL

My capacitors are the same as originall coguar in the picture top left green and black tape conected by wieres with B- and B+ with power board.

Coul you tell me more about snubber, like an RC snubber what parametrs I could try?

My problem at the moment is that controler works with 100A battery limits when I have incresed current to 200A mosfets blown up and get short circuit

It's a bit hard to tell where things are in the picture, but ideally the power connections between the capacitors, mosfets, and diodes be as short as possible to minimize parasitic inductance.

If I remember right, I measured the voltage spikes on the mosfets of the power board for the cougar controller to be about 20V above the battery voltage (also depends on the motor current). If your configuration doesn't have similar characteristics, the voltage spikes could be exceeding the mosfet voltage rating.

It would be great to get ahold of an oscilloscope so you can investigate what these spikes are for your configuration.

I've never had to use an RC snubber, but if you search the net there are design resources out there.

[duncan]

Hi Paul

I've had a fun time, did an autokana - great fun
Then I blew some cells
Rebuilt with 40S x 3P (16Ah Headways)
(was 44S)

With the lower voltage my current has gone up and I think I have hit the controller over-temperature

does it just de-rate or does the frequency change?
I could hear a funny "rubbing noise" - I didn't think of temperature at the time
by the time I got back to the car it was all working fine - also no noise

Seems to be OK now

[flores]

Originally Posted by duncan

does it just de-rate or does the frequency change?

To my knowledge the frequency is always fixed.

[duncan]

To my knowledge the frequency is always fixed.

Ok
What happened
I drove out of town - checking my Cycle Analyst against a GPS - doing 105Kph - damn close
Noticed I was pulling 250 amps
Turned around,
Back in town - heard a "rubbing sound" - unable to get full power
Battery voltage was not too low - just very little current even at full throttle
Limped home
Car in garage - checked the drive-train all looked OK
I worried that something had happened to the brushes and set up an inspection camera - looked OK
By then about an hour had passed - then I thought about over-temperature - but everything felt OK
Tested the car - everything normal
Except that I am using more amps (which is expected as I have dropped from 44S to 40S)

[apowers]

Duncan

When the current limits , the controller makes a funny noise while it is skipping a "beat". Maybe it does that with over temp also.

Alvin

[jackbauer]

What would be involved from a software perspective to implement an idle function in the revolt? Was thinking along the lines of a freq to volt converter to ease the load on he processor.

[flores]

Has anyone heard something from Paul? Looks like he has been offline for a while now.. I'm sort of concerned..

Has anybody info on that?

[flores]

So.. there are three 1000a prototypes build by Paul of which I own one.

I never got to test it because I had to swap my batteries and motor first, which took a while for reasons I will not discuss now.

But today I finally mounted the 1000a in the car. There was a 500a in it before that, so I know all my components are good.

There isn't much documentation on the 1000a and I have a few questions I hope some one (the other 1000a owners?) has the answer for.

First of the busbar connections.. I'm pretty sure the middle is the motor - but what is b+ and b- ? Guessing b+ is the closest to the capacitors? Like the 500a?

And this model had a precharge.. and the is one connectionwire for it.. where do I connect that to?

I connected to 12v and the throttle, this gives me a fast flashing led.. what does that mean? I guess some sort of error code?

Thanks

[MPaulHolmes]

Hello! Sorry, my life has gotten really busy, and I haven't been on here at all. But I am doing some interesting things for a company I work for at home. Even NASA is interested in one of the things they are doing.

Duncan, the temperature protection works as follows:

if around 75 degreesC, maximum motor amps are 7/8*500.
If around 85 degreesC, maximum motor amps are 0/8*500.

And it smoothly goes from 7/8 down to 0/8 as the temperature climbs from 75 up to 85. So, that definitely sounds like what was happening to you, duncan. You might need a heat sink with fans.

Flores, could you post a picture? I don't even remember anymore, but I bet seeing it would jog my memory. If I were to guess, I'd say it's the same order for B+, M-, B- as the 500amp version. B+ is next to the capacitors, then M-, then B-. Could you also take a picture of the wires? Did you build this or did I?

What would be involved from a software perspective to implement an idle function in the revolt?

I don't think it would be that bad. That's my guess at least.