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  1. mxlemming

    SOLO Motor Controllers

    VESC has 3 HFI modes. There's the old one based on fft and the newer ones based on a tracking pll. The new ones are much much quieter. With smaller and high performance hardware, the HFI can be run silently. The solo sounds rather loud by comparison, though i think some of that is due to the...
  2. mxlemming

    My Brushless Design for Hall Effect Type Motors, Looking for Suggestions

    Very Nice. Glad you got it working well! I never really used common mode chokes. I presume they work in circumstances they're good in. Concept of your driver looks fine to me, but the detail of ground and power planes etc... Dunno. Did you write the code yourself as well?
  3. mxlemming

    FOC questions

    Without knowing exactly how you've implemented the duty mode and sensors observer with duty mode it's very hard to say. One thing of note is that if you're limiting the duty, the current control can no longer be effective, and depending which variables where and how you're using them, the...
  4. mxlemming

    FOC questions

    I barely use the hall sensor code. Sensorless runs much smoother and more efficiently. The hall sensor code runs based on having a table of the angles of the changes between states (the signal edge angle) and polling the hall sensors once per pwm cycle. This avoids noise pickup on the sensors...
  5. mxlemming

    Current Sensing

    After dead center. To minimize noise you want to allow the opamp as much time as possible to stabilize and for transients and noise to decay.
  6. mxlemming

    Current Sensing

    Obviously you're looking to sample when the low side mos is conducting so if your code is written upside down you need to adjust the logic accordingly.
  7. mxlemming

    Current Sensing

    I've built inverters with the ring sensors, allegro chip sensors, low side shunts, phase shunts... I can confirm all work well with good design, and all work equally badly if you mess up the design of the board or inverter logic. I've successfully used low side shunts for boards running <10A and...
  8. mxlemming

    Motor Pole Pairs and Rotor Position

    Unfortunately amberwolf comment doesn't really make sense. You either have measurement error, increased ripple at lower duty or a control scheme error. It shouldn't be the case that slower uses more current. You should be triggering the ADC at either cnt=0 or cnt=arr with center aligned PWM...
  9. mxlemming

    FOC questions

    Terrestrial or ground based vehicles always want torque mode. Some people run balancing vehicles with position, duty or speed but I don't think this is right. For duty mode, you might choose to buffer the throttle request and only let it decrease the duty if the iq being regenerated is low to...
  10. mxlemming

    Motor Pole Pairs and Rotor Position

    Svpwm doesn't require angle as an argument so if that's happening after the inverse Park, it's not clear why he's doing it atall. It's possible to derive the angle from a variety of sensorless observer means and many of them result in an arctan as the final step, so without the rest of your...
  11. mxlemming

    Motor Pole Pairs and Rotor Position

    2000 counts might well be 8000 pulses in quadrature. So 8pp and there's your 1000 But it's hard to tell from tiny code snippets. Be sure though, if it spins, the numbers work out somehow you just need to think hard and look more carefully.
  12. mxlemming

    Motor Pole Pairs and Rotor Position

    It's in there somewhere, that factor of 4. Might be hidden, rolled up in don't other constant or whatever.... But it's in there. It won't work without it.
  13. mxlemming

    Modular, Multi-Platform, 300A ESC

    There's a pre made header file for this board for VESC, you don't need to make your own. You are using VESC right? Iirc the dead time is 800ns
  14. mxlemming

    Modular, Multi-Platform, 300A ESC

    What firmware? 250ns is almost certainly about 1/3 of what you need. Normally i run 800ns on the MP2 You'll need to set different parameters for motors. Resistance, inductance and flux linkage. It can be run with all sorts of motors, i haven't found a motor it won't run yet. You'll need to...
  15. mxlemming

    Is a 50KW Out Runner motor any good for a retro street motorcycle?

    Sure, with enough voltage you can get as much power as you want. I have the 65kV version, on 20s. It free spins at about 1000eHz, 4300rpm. At that speed, it gets very hot even just free spinning. I take your point that with 30s, I could spin it 1000eHz and would be able to hold much higher phase...
  16. mxlemming

    Is a 50KW Out Runner motor any good for a retro street motorcycle?

    This is actually quite a big motor at 6" diameter and 4"high. Many people have created motorbikes with similar. 50kW is probably a pipe dream though, as scianiac points out. I have the 120mm diameter version on my bike and it's no use above about 6 or 7kW, due to the inductance you just can't...
  17. mxlemming

    Motor Winding Calculations & Cooling Design

    You cannot rewind your pmsm to be less "hot". Your motor core saturation is defined by the magnets at low loads and the magnets in quadrature with the coils at high loads. To get a given torque, you need a given magnet strength and a given number of ampsxturns. However you rewind it, the flux...
  18. mxlemming

    Motor Winding Calculations & Cooling Design

    The motor flux is determined by the magnets predominantly for a permanent magnet setup. Your book is most likely dealing with induction motors which have no magnets and therefore the flux is determined by the winding. So if you don't change the magnets but you wind with more turns then it will...
  19. mxlemming

    Design/Build a flyback converter

    I would not advise using the NCP1377 like I did for anyone reading - On Semi list it as obsolete now. Wish I had realised that before using it for the design. Plenty of alternatives, but they all have some funny feature or other.
  20. mxlemming

    Design/Build a flyback converter

    Seems to be the basis for most of the laptop chargers I have ripped apart (only about 3 or 4) with an up front power factor correction stage. Fly buck is pretty useful, I have been considering using them as well. You can make a flyback/buck with 3 outputs (or more!)for a 3 phase bridge quite...
  21. mxlemming

    Any controllers capable of maintaining smooth RPM decay rate under suddenly varying load?

    I think at some stage, you need to accept there is a degree of programming and tuning required for this. As you observe, a physical flywheel and clutch is basically a requirement for the violent acceleration you want. In terms of controller, in torque mode this is not hard, currents can be...
  22. mxlemming

    Any controllers capable of maintaining smooth RPM decay rate under suddenly varying load?

    I think you need to remap your problem to a paradigm that motor controllers understand. High tech motor controllers control current, which is torque. The rpm control is an abstraction on top of that. I do not think you actually want to control RPM in any way, you may think you do, because you...
  23. mxlemming

    Yet another Lebowski + Honda IMA inverter & step-by-step

    I got it working with pretty big phase current (160A). Had about 2/3 my weight on the bike saddle. I'm 90kg. Unfortunately it's only silent because I'm running 35khz pwm so half that from positive and negative injection is 17.5kHz Something worth noting is that if you construct your injection...
  24. mxlemming

    FOC questions

    The simplest way to startup nicely is to use flux linkage observer and preload it with openloop values varying sinusoidally with time. If you keep running the actual observer inn the background, then at some point just stop preloading and it's already in closed loop.
  25. mxlemming

    FOC questions

    I think you've hit one of the issues with a direct voltage arctan observer, there's angle ambiguity. The same voltage generated regardless of which way you spin... This doesn't happen with flux linkage. HFI. You inject a positive and then equal negative voltage in dq immediately after ADC...
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