openinverter forum

If you put the slip slipmin less than 7 Hz the motor does not accelerate and takes a large current

yaroslav wrote: ↑Fri Mar 27, 2020 8:25 am If you put the slip slipmin less than 7 Hz the motor does not accelerate and takes a large current

Hm... maybe you would need more boost then.
When first i calibrated my motor i tried with something line 5000 boost and motor would start with slipmin 3 etc... However it would be like a rubber band. If i would give it less throttle it would require it to move a bit before torque would be good enough.
It had caused several IGBTs to brake with gen1 drivers.
When i first used Skyper32 drivers with desat and dead time calculation they would quickly trip fault signal with original settings. Only when i gave it enough boost voltage on start could i use less throttle and have more accurate pedal travel at 0. So my second boost setting was 7000!
Mind you if i would add just a tad more boost then on hard acceleration i would get desat fault from drivers... there is a sweet spot with votlage.

yaroslav wrote: ↑Fri Mar 27, 2020 8:25 am If you put the slip slipmin less than 7 Hz the motor does not accelerate and takes a large current

Are you sure your encoder numimp is set up correctly? Are you getting regenerative breaking? 7Hz just to get going sounds like way too much. Usually fslipmin is in the 1-2Hz range.

Yes, when I reset the gas pedal the engine stops abruptly, the encoder is correctly configured, I even counted the pulses they get 48

yaroslav wrote: ↑Fri Mar 27, 2020 12:37 pm Yes, when I reset the gas pedal the engine stops abruptly, the encoder is correctly configured, I even counted the pulses they get 48

I think 7Hz is characteristic of small rotor and canted rods inside to get more torque from small motor. This means that you need more voltage to keep magnetic force attached. I think more Hz will mean more Amps too. This may quickly lead to overheating.
Just try to use my minslip calibrating scheme from wiki.

I have already tried everything, it only works normally with this slipmin=7

Hi, an error was found on the kty81 temperature sensor, it was necessary to put in the file temp_meas.cpp : NTC, Kty81


static const TEMP_SENSOR sensors[] =
{
{ -25, 105, 5, TABLEN(JCurve), NTC, JCurve },
{ 0, 100, 5, TABLEN(Semikron), PTC, Semikron },
{ -5, 100, 5, TABLEN(mbb600), PTC, mbb600 },
{ -50, 150, 10, TABLEN(Kty81), NTC, Kty81 },
{ -50, 150, 10, TABLEN(Pt1000), PTC, Pt1000 },
{ -50, 150, 5, TABLEN(NtcK45), NTC, NtcK45 },
{ -10, 100, 10, TABLEN(leafhs), NTC, leafhs },
{ -50, 170, 10, TABLEN(Kty83), PTC, Kty83 },
{ -40, 300, 10, TABLEN(Kty84), PTC, Kty84 },
{ -20, 150, 10, TABLEN(leaf), NTC, leaf },
{ -20, 190, 5, TABLEN(Tesla100k), PTC, Tesla100k },
{ 0, 100, 10, TABLEN(Tesla52k), PTC, Tesla52k },
};

Can there be errors in other NTC PTC sensors?

So this is tested and working? I haven't tested all sensors myself so there might be other errors

it worked when I was able to compile the source code, I started looking for the reason, I changed PTC to NTC in the code, and the temperature reading was correct, now can you fix it in the source code and compile the firmware?

I suggest making a new section on the forum, which will add only identified errors in the program

yaroslav wrote: ↑Mon Apr 06, 2020 8:57 pm it worked when I was able to compile the source code, I started looking for the reason, I changed PTC to NTC in the code, and the temperature reading was correct, now can you fix it in the source code and compile the firmware?

Hm... KTY81 is PTC sensor. Did you maybe forgot to add TWO 500R resistors? And do you connect it the correct way?
I only used KTY84 and Ampera sensors though.

Ok, the firmware here viewtopic.php?f=18&t=673 also has this changed.
In fact PTC and NTC refers to the temperature coefficient of the ADC value. And that is inverted for the heatsink temperature because the sensor pulls the input to 5V i.e. resistance has a positive temperature coefficient (more temp, more resistance) then voltage has a negative temperature coefficient

johu wrote: ↑Wed Mar 25, 2020 2:41 pm Of course it can be extended, but more than 10Hz is beyond any reason. Why would you need more?

Please Johannes is there a firmware that has got extended slip setting or how to extend it? I am trying to run synchronous motor with sine firmware and I need a little bit more speed. I got it with fslipspnt parameter in testing but in run mode that parameter is not effective. I only need to drive the car few hundred meters at speed up to 30 km/h..