Search found 336 matches

by marcos
Jul 07 2020 12:09pm
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 56
Views: 5138

Re: I designed a +200A powerstage with 200V MOSFETs (video of it working)

.The VESC software is only measuring the inductance at 1/3rd of actual on my meter. I need to look at the code and try some different motors. Maybe I can mod the code to be more accurate for the PI controller gain calcs. Inductance measurement error is a known vesc issue on 3rd party hardware. I gu...
by marcos
Jun 23 2020 7:13pm
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 482
Views: 114495

Re: Axiom: a 100kW+ motor controller

Axiom crew, Do you know how many people have been making derivative works of your schematic? It's got some really nice features put into it. I've made some minor tweaks to it for my own use, like discrete logic in place of and FPGA for fault detection, cause I don't have time to learn how to FPGA. ...
by marcos
Jun 22 2020 6:24pm
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 482
Views: 114495

Re: Axiom: a 100kW+ motor controller

@HighHopes or at @marcos How do you guys deal with the VESC's non-ideal behavior with slower-switching hardware? I've been able to observe in my own testing that the VESC firmware depends on hardware that switches really fast in order for the motor detection and control to perform as expected. I sa...
by marcos
Jun 19 2020 3:17pm
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 482
Views: 114495

Re: Axiom: a 100kW+ motor controller

The plan is to initially roll out Axiom as a Leaf-specific motor drive to provide a turn-key solution. Other motors are likely to need more support so we need to limit and optimize the amount of man-hours spent on each axiom. We're currently working on the enclosure and planning a Rev2 board with ve...
by marcos
Jun 18 2020 5:54pm
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 482
Views: 114495

Re: Axiom: a 100kW+ motor controller

This was posted on hackaday, but I figured I'd share here as well MTPA merged into VESC firmware! MTPA stands for Maximum Torque Per Amp, which means that for a given current flowing into the motor phases it produces the maximum torque possible. We'll find out the benefits doesn't stop there. Typica...
by marcos
Jun 12 2020 12:10pm
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 482
Views: 114495

Re: Axiom: a 100kW+ motor controller

Yes! The pull request to merge MTPA is pending approval here:

https://github.com/vedderb/bldc/pull/179

We have been testing it at 800Amps on axiom and its working well. It is also under test on a smaller 150A drive with good results as well so I hope it gets merged soon.
by marcos
May 07 2020 7:53am
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 482
Views: 114495

Re: Axiom: a 100kW+ motor controller

I think what Arlo1 does here is not what I do... I have a 45 degree rotation in the error signals of Id and Iq, this is fundamentally not the same as a 45 degree rotation in the resolver output... with the rotation in the resolver signal you will not be FOC anymore as you also rotate the wanted Id ...
by marcos
Mar 17 2020 6:22pm
Forum: Motor Technology
Topic: True FOC: definition and examples
Replies: 77
Views: 5245

Re: True FOC: definition and examples

I don't think any shunt/sensor configuration is more "true" as long as the controller is working in the two axis rotor frame. I assume that "two axis rotor frame" concept is related to calculating Quadrature/Torque (Iq) current vs Flux/Direct (Id) current via Clark/Park-transfor...
by marcos
Mar 17 2020 9:24am
Forum: Motor Technology
Topic: True FOC: definition and examples
Replies: 77
Views: 5245

Re: True FOC: definition and examples

In my mind, field oriented control does the motor control in the rotor frame. So if the torque control is based on setting an iq and id current, that's FOC. iq/id are the currents in the rotor reference frame. So if you are standing in the rotating rotor, you see DC currents instead of sinewaves. ht...
by marcos
Mar 07 2020 6:01pm
Forum: Motor Technology
Topic: Does adding more cap to the DC bus on a controller help? Look in here for the answer.
Replies: 10
Views: 958

Re: Does adding more cap to the DC bus on a controller help? Look in here for the answer.

Back of the envelope calcs sound reasonable, thanks. Looks like a loose power input connector shouldn't make much damage. Something to think about is that when you have a battery disconnect event, it could be a short somewhere that is tripping a fuse or contactor, and they trip at currents quite hig...
by marcos
Mar 07 2020 12:03pm
Forum: Motor Technology
Topic: Does adding more cap to the DC bus on a controller help? Look in here for the answer.
Replies: 10
Views: 958

Re: Does adding more cap to the DC bus on a controller help? Look in here for the answer.

Does a large inductance between battery and DC link change the voltage situation?
For example during normal operation and also when the BMS disconnects the battery at peak current.
by marcos
Mar 05 2020 4:01pm
Forum: Motor Technology
Topic: What's so bad about low impedence?
Replies: 30
Views: 1897

Re: What's so bad about low impedence?

peters wrote:
Mar 05 2020 5:16am
The problem with low inductance is that the phase ripple current within a PWM cycle can be too high, because the BEMF and the battery voltage is different and the inductance is between them, and may exceed an overcurrent trip threshold (or something else..).
^exactly this
by marcos
Feb 19 2020 12:58am
Forum: Motor Technology
Topic: Cheap FOCer 2 (Open-source, Low-cost, VESC 6 based ESC) (v0.9 release! Beta testing still ongoing)
Replies: 55
Views: 9769

Re: Cheap FOCer 2 (Open-source, Low-cost, VESC 6 based ESC) (Prototyped. Materials have arrived for a test batch)

Distilled water is orders of magnitude less conductive than tap water. If a powerful fan doesnt cut it, or if the dyno doesnt fit in a fridge I would give pure water a try. Mineral oil isn't as great moving heat away, and its messy. Maybe rub a bit the motor with alcohol to make it extra clean so it...
by marcos
Feb 01 2020 12:25pm
Forum: Motor Technology
Topic: Cheap FOCer 2 (Open-source, Low-cost, VESC 6 based ESC) (v0.9 release! Beta testing still ongoing)
Replies: 55
Views: 9769

Re: Cheap FOCer 2 (Open-source, Low-cost, VESC 6 based ESC) (Prototyped. Materials have arrived for a test batch)

During double pulse test you want to look at the gate that is kept always off. Here you can see how the gate turn on looks like. Also, when you make RgOFF larger (slower turn off, less overshoot) you are making miller turn on worse because driver loses strength to keep the gate at 0V, so its not a s...
by marcos
Jan 31 2020 10:41pm
Forum: Motor Technology
Topic: Cheap FOCer 2 (Open-source, Low-cost, VESC 6 based ESC) (v0.9 release! Beta testing still ongoing)
Replies: 55
Views: 9769

Re: Cheap FOCer 2 (Open-source, Low-cost, VESC 6 based ESC) (Prototyped. Materials have arrived for a test batch)

Slowing down the switching won't hurt much if you don't use very high switching freq like 25+kHz. High end VESCs often switch at 25 or 30khz because the observer works better with more sampling per second, but you can halve that by sampling on both V4 and V7. Its important to take a look at the gate...
by marcos
Jan 21 2020 12:59pm
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 482
Views: 114495

Re: Axiom: a 100kW+ motor controller

Hello, someone has tested FF600R06ME3 from aliexpress?, prices are 1/4 the price at mouser! about 40€, is it possible? Most likely counterfeit, and most likely its not worth the risk if a total fire costs you more that what you saved in those IGBTs. On other news, we got merged some features for be...
by marcos
Jan 11 2020 4:31pm
Forum: Motor Technology
Topic: Serious FOCer (84V VESC 6 based controller)
Replies: 287
Views: 44069

Re: Serious FOCer (84V VESC 6 based controller)

Instant kills are usually caused by overvoltage or shoot through events, both can be seen in a double pulse test. Before performing any high power test your gate drive should be tuned based on your double pulse test results. If the long gate traces are too susceptible you will have to reduce the gat...
by marcos
Dec 14 2019 8:38am
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 482
Views: 114495

Re: Axiom: a 100kW+ motor controller

Hey marcos what is status of MTPA and flux weakning. I want to test switched reluctance IPM motor on this controller. That branch is quite behind the latest master branch, and requires you to build both vesc firmware and vesc tool in order to have the features. FW still lacks a safety feature that ...
by marcos
Dec 07 2019 10:51pm
Forum: Motor Technology
Topic: Max erpm and field wakening
Replies: 11
Views: 1707

Re: Max erpm and field wakening

Different conceps there * Max eRPM refers to the base frequency of the motor drive. If controller states 60kerpm then its PWM can generate 1kHz sinewaves while keeping the motor under control. * Max switching freq refers to the transistor switching freq, it could be 15, 18, 21kHz for example. Note h...
by marcos
Nov 22 2019 10:15am
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 482
Views: 114495

Re: Axiom: a 100kW+ motor controller

The Axiom part starts at 13:15 in the video. Soooo good to see you together on the stage, deep respect and congrats! The whole thing was an awesome meetup, and it was great to have the chance to finally have a team meeting, here are 4 glasses for maxi that didn't make it. 20191116_134321.jpg Btw I ...
by marcos
Nov 03 2019 10:26pm
Forum: Motor Technology
Topic: Sensorless From Standstill (SFS) explained
Replies: 24
Views: 3815

Re: Sensorless From Standstill (SFS) explained

That's a very awesome and valuable contribution Lebowski, thanks!! I'm not sure the STM32F4 can handle this non-center-alignement phase shift, I think it requires the coordination of many many timers. In any case, I sent the tip to benjamin vedder, we was considering this kind of signal injection so...
by marcos
Oct 28 2019 7:22am
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 482
Views: 114495

Re: Axiom: a 100kW+ motor controller

I thought VESC already supports multiple VESC with multiple motors over CAN? Is that not what Vedder describes as Arrays of VESCs or are we limited to an array of two VESCs only in Version 6? How do they implement e.g. 4wd skateboard with 4 VESC & 4 Motors? Are they simply running 4 motors off ...
by marcos
Oct 22 2019 9:31am
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 482
Views: 114495

Re: Axiom: a 100kW+ motor controller

Does this controller have the ability to daisy chain, so if you had 4 motors, and 4 controllers, you could connect the throttle to one acting as the master controller, which would send data to the other 3? Everything is possible. The only limit is your imagination and your time. And the flash memor...
by marcos
Oct 16 2019 4:54pm
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 482
Views: 114495

Re: Axiom: a 100kW+ motor controller

I watched one of Arlin's videos on the Axiom he's using in his Honda and he suggests there might be Torque Vectoring possible/coming? I assume Traction Control is already possible through VESC software anyway, but are there plans for Torque Vectoring to be available or is Arlin developing this just...
by marcos
Sep 30 2019 5:14pm
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 482
Views: 114495

Re: Axiom: a 100kW+ motor controller

would like to ask also any update on the pcb that would let us adapt let say already built powerstage from some inverter to the axiom logic board? No updates in that regard. I have the kicad files ready to upload, they didn't change since we defined the general layout and pinout. I just never made ...