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  1. Mihai_F

    FOC questions

    @mxlemming Previously i measured resistance with the "4 wire method" and it gave out that 230mohm, so.... I checked the motor resistance, well it was wrong by a factor of ~10. I checked in 2 ways, the first i found some info on the net that these motors have about 36mohms, the second i reversed...
  2. Mihai_F

    FOC questions

    @mxlemming I do believe that there-s an issue some ware, but this hardware New 100A FOC controller project is with TOLL fets, all nicely and clean switching , low inductance layout, all the goodies and this is where i'm testing my FOC SW... so i don't know, but switching might not be the blame...
  3. Mihai_F

    FOC questions

    @mxlemming Now it makes sense to me, a few things that are happening: that is why only after a certain load/ Ph amps it loses sink during crossing from sensored to sensorless. In the flux formula, if the Voltage Va (or Vb) is smaller that Ia*Rm then Va-Ia*Rm tends to zero or even negative, i...
  4. Mihai_F

    FOC questions

    @mxlemming also how do you consider Ld and Lq for motors with winding delta or Y termination, i mean you measure with the LCR between 2 phase of the motor, than for Y termination you divide by 2 the value from LCR? how about Resistance? the same as inductance? how about delta termination then...
  5. Mihai_F

    FOC questions

    @mxlemming i'm using predefined angles for each the 6 sectors during hall startup, the flux observer runs in the back to be ready for crossing to sensorless , then after a certain erpm threshold it switches to sensorless (fluxobserver). the problem that i'm having with hall start up, is that...
  6. Mihai_F

    FOC questions

    hy, thanks for clearing that up. I have another question about hall startup, i see that you store (preload) the hall flux during run at speed and use it at low speed (to start the motor), my question is, after controller power up, and motor was not spined yet, and there are no stored hall flux...
  7. Mihai_F

    FOC questions

    hy, happy new year! can you explain a bit why it is needed to have injection at bottom pwm and at top pwm, what does it differ if you inject at top or at bottom, for inductance measurement. i'm having a hard time getting useable current values it i inject at top for inductance measurement.
  8. Mihai_F

    20Kw motor and 300A ESC (ultralight aircraft propulsion system)

    Logic11 Thanks! Hybrid applications for land vehicles is not the same as for aircraft, and what i mean by that, is the RPM and speed range and the variations of those. With a land vehicle you start and stop moving and accelerate and decelerate way more frequently (as the road/ traffic imposes)...
  9. Mihai_F

    FOC questions

    i have a question regarding _motor->FOC.inject = 0/1 inject at top or at bottom PWM, what is its purpose during motor parameters measurement functions ( Rm Lq Ld fluxlinkage), ca you explain a bit the reason for doing that. i'm trying to implement a motor parameters measurement and i'm having...
  10. Mihai_F

    VESC Tuning tips

    Hy, nice, that is a solid explanation, man if you had made this post a few months ago, i had a lot of head bashing with my FOC code since then, (FOC questions thread....), now this clears some things out.
  11. Mihai_F

    New 100A FOC controller project

    yeah that is a good one :D , heard of that EMI topic for me is to keep it inside and not get out the "box", to protect the radio reception, comms.... There was a team at solar car racing that used some vesc based controller, they had big trouble tuning it to the motor, and it was running verry...
  12. Mihai_F

    FOC questions

    hy @mxlemming, i have a question regarding, flux linkage max / min limits used in the flux observer, why 1,7 and 0,5 during the calculation of min and max. does it ever need wider range, like in really big motors? i noticed that for small motors the flux_a and b "range" is smaller never reaches...
  13. Mihai_F

    New 100A FOC controller project

    yep, the box is grounded to B- , mostly for EMI shielding, although the heatsink is isolated from vehicle chassis ground, the electric propulsion has its own ground witch is isolated from vehicle ground. I know and understand what you say about grounding the heatsink/chassis to B-, one plan for...
  14. Mihai_F

    New 100A FOC controller project

    You need 2 pulses, one long in order to raise the current, and the second to switch the DUT on/off in that current .For 127A in 24uH inductor at 40V the pulse was ~130us. Over current detect is SW, in 44us intervals , pwm triggering injected ADC for current.
  15. Mihai_F

    New 100A FOC controller project

    i'm back with measurements, I did the double pulse test, supply 40V inductor 24uH, first did 97A then 127A, then went full hog with 148A and 183A twice, and the software overcurrent protection kicked in and stopped the second pulse. (unfortunately SW protection is not like HW desat protection in...
  16. Mihai_F

    Project FT00 - A compact 125V 30kW motor with 6.77 planet output

    Man... this looks good!! awesome work! outstanding! :bigthumb: Extracting the heat from that 800w ish winding power loss might be a challenge, i know this from my 20Kw aerouse motor, that is not a easy task. I talked with some guys that do electric F4 racing, and they had success with slow flow...
  17. Mihai_F

    New 100A FOC controller project

    Hy guys, As mentioned in my post New Custom Motor Project for Solar Car Here i'l describe the FOC controller. It's design begun a year ago, when i started looking into making an single board all smd FOC esc and also started developing the FOC code for STM32 uC-s. A verry big inspiration for code...
  18. Mihai_F

    New Custom Motor Project for Solar Car

    Hy guys, I have been "cooking" a lot in this summer, Recently i embarked in a project with TUCN Racing Team (Technical University from my town), to build a custom motor and a controller for they're electric solar car, in order to compete in the ilumen European Solar Challenge 24h endurance...
  19. Mihai_F

    Motor Winding Calculations & Cooling Design

    here is something interesting and new regarding electric motors in cars, enjoy.
  20. Mihai_F

    Motor Winding Calculations & Cooling Design

    For anyone ho want's to use the excel calculator, please use the updated version 09-24, i updated the file today, the old one had some mistakes. This version is checked up by real motors, i reverse engineered 3 motors and the calculation matches (90-95%) the real build.
  21. Mihai_F

    FOC questions

    @mxlemming hy, i sorted some things out, i was using wrong ecuations from turorials for FOC algorithm, the reason nothing worked as expected... ,now i use the ones in MESC, now the flux observer works (MESC version with integration), now it keeps the rotation direction and it changes only when i...
  22. Mihai_F

    FOC questions

    I do not use integration, because winds up and does not center well, just flux=V-(i*r) *(1/freq)-L(i-i_prev), then LPF as an pseudo integrator like they say in the document, so after LPF there is no bias no decentering no windup, just flux with some phaseshift, then atan2 to get the angle. (the...
  23. Mihai_F

    FOC questions

    I found this document https://s3.amazonaws.com/scolton-www/motordrive/sensorless_gen1_Rev1.pdf that discuses FOC but the interest is the Flux Observer and in particular the integration problem (page 29), My flux observer with low pass filter working got suddenly explained in that paper, they...
  24. Mihai_F

    FOC questions

    @mxlemming , i have a question regarding SI units for the inputs of the flux observer, "flux_a = flux_a + (Vab.a - m.R * Iab.a)* pwm_period- m.L_D * (Iab.a - Ia_last)" Vab.a is in Volts aka V m.Rin is in Ohms aka "omega" Iab.a is in Amps aka A pwm_period is 1/PWM freq in Hz (ex. 1/20000) m.L_D...
  25. Mihai_F

    FOC questions

    O yes, that is crap for switching, this setup is just some beefy parts that i had around and would be strong enough to drive my ass around for some fun, and test the FOC SW, plus this bundle of wires between bords was a nightmare of noise and crap signal, as soon as the phase amps got over 50A...
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