Search found 2844 matches

by zombiess
Oct 18 2021 1:15pm
Forum: Motor Technology
Topic: 300A bldc esc, mosfets ringing, help
Replies: 27
Views: 483

Re: 300A bldc esc, mosfets ringing, help

Mihai_F, do you have a schematic for your design?

Read this before deciding to switch devices as fast as possible. Choosing device switching time is about balance.

https://toshiba-semicon-storage.com/inf ... ?did=59464
by zombiess
Oct 13 2021 11:29pm
Forum: Motor Technology
Topic: 300A bldc esc, mosfets ringing, help
Replies: 27
Views: 483

Re: 300A bldc esc, mosfets ringing, help

I'm curious as to what benefit you are getting adding decoupling capacitors. I've found that with a good layout that my DC Link cap is enough and no additional capacitance is required unless I add a RC/RCD snubber, but then the application is different. I've also found adding capacitance down stream...
by zombiess
Oct 13 2021 5:47pm
Forum: Motor Technology
Topic: 300A bldc esc, mosfets ringing, help
Replies: 27
Views: 483

Re: 300A bldc esc, mosfets ringing, help

I'm thinking to use polypropylene caps (i have some 1uf 250vac big ones) for decoupling or ceramics, but i'm afraid of those becose they fail with no worning and are kinda distructive, aldo pp caps are not as good as ceramics at decoupling, il try it and see. Polypropylene caps are often the best c...
by zombiess
Oct 13 2021 9:02am
Forum: Motor Technology
Topic: HESC V1 150v 600Amp VESC based motor controller
Replies: 32
Views: 2282

Re: HESC V1 150v 600Amp VESC based motor controller

Where are the DC Link caps?
Where does the power feed into the controller?
How are you removing heat?

The power feed order should be:
Battery -> DC Link Cap -> DC bus
by zombiess
Oct 13 2021 1:21am
Forum: Motor Technology
Topic: 300A bldc esc, mosfets ringing, help
Replies: 27
Views: 483

Re: 300A bldc esc, mosfets ringing, help

Sorry if this comes off a bit harsh, but you are venturing into aerospace engineering in what appears to be an unprepared manner. The following isn't meant to be negative, it's meant to make you think. Just my personal opinion, but I think flying with the controller setup pictured is bad risk manage...
by zombiess
Oct 02 2021 11:48am
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 65
Views: 7039

Re: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)

This loop stability thing perplexes me. I would have thought these chips would be working as one shot control, cycle by cycle, so the concept of loop stability should be kind of moot. I wonder if your noise problem would be well tackled like this: Reduce inductance.PNG The way I see it, your V+ and...
by zombiess
Oct 01 2021 7:44pm
Forum: Motor Technology
Topic: 1S100P boost controller
Replies: 10
Views: 306

Re: 1S100P boost controller

The topology they use to buck which has active mosfet rectification on each end also works bi-directionally. They do it so they never eat diode body forward voltage losses at the 150-200Amp core currents, because when driving into a 1-0.8Vdc load, Vf voltage drop loss would be over half the power t...
by zombiess
Oct 01 2021 7:22pm
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 65
Views: 7039

Re: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)

You might consider selling the SMPS without the rest of the kit. 22$ is a considerable BoM cost Guessing that is a part from Analog devices controlling it? I have been thinking through this and come up with nothing remarkable; my thought has been going as far as using an STM32L0xx series chip to dr...
by zombiess
Oct 01 2021 1:38pm
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 65
Views: 7039

Re: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)

I'm especially interested in your SMPS. The limiting factor for me for a while has been cost effective robust dcdc step downs... The TI lm5xxx ones just blow at the drop of a hat, usually when i do something like short a motor phase (which the FETs aren't affected by). They also limit the applicabl...
by zombiess
Sep 29 2021 9:35pm
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 65
Views: 7039

Re: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)

I just stumbled across this from YouTube. Is there any progress on this controller? Yes, I have made some progress on design, but not in production. I have an updated design with manufacturing in mind if I ever get there. The new power stage pulls from what I learned from this one and has 18-24 TO-...
by zombiess
Jun 13 2021 12:18pm
Forum: Motor Technology
Topic: Non-silicon and/or soft-switched controller topologies?
Replies: 63
Views: 1852

Re: Non-silicon and/or soft-switched controller topologies?

Why not a phase shunt/other current measurement and a comparator? That could be made to trip within 1-2us, which would almost certainly protect from phase dead short. Shoot through (this is an area where me, Marcos and Zombies are in some contention) I think you can manage by having gate drives tha...
by zombiess
Jun 12 2021 6:56pm
Forum: Motor Technology
Topic: Non-silicon and/or soft-switched controller topologies?
Replies: 63
Views: 1852

Re: Non-silicon and/or soft-switched controller topologies?

As far as shoot through is concerned, what's your recommended way for detecting and surviving that? I figured that bus input current would spike and you'd see it on the DC bus, but I don't know if that would be fast enough to save everything. A gate drive which is able to detect it and take action....
by zombiess
Jun 12 2021 12:39pm
Forum: Motor Technology
Topic: Non-silicon and/or soft-switched controller topologies?
Replies: 63
Views: 1852

Re: Non-silicon and/or soft-switched controller topologies?

Darn it. My exploration into GaN is being thwarted because Coss losses dominate my device selection. My current Si part works better than most parts I'm finding.
by zombiess
Jun 12 2021 11:17am
Forum: Motor Technology
Topic: Non-silicon and/or soft-switched controller topologies?
Replies: 63
Views: 1852

Re: Non-silicon and/or soft-switched controller topologies?

If you follow zombiess advice, you'll definitely end up with something that works well and reliably. He does this for money I believe, he has a strong interest in making things that work and don't fail. But that's not much interest to me. I would rather see you fail and learn a whole load than succ...
by zombiess
Jun 11 2021 11:04am
Forum: Motor Technology
Topic: Non-silicon and/or soft-switched controller topologies?
Replies: 63
Views: 1852

Re: Non-silicon and/or soft-switched controller topologies?

Honestly, I'm using GaN and high Fsw as much to get the hang of working with GaN and high-frequency switching for future power converter designs as anything else; I also am really interested in using an Emrax motor to build an EV with, but the resistance and inductance are low enough that I assume ...
by zombiess
Jun 10 2021 11:43pm
Forum: Motor Technology
Topic: Non-silicon and/or soft-switched controller topologies?
Replies: 63
Views: 1852

Re: Non-silicon and/or soft-switched controller topologies?

Thanks! Completely unrelated question; what bit depth did you use for PWM on your custom controller, and what's the minimum bit depth you recommend? The Zynq platform I'm looking to use to do the control design on has a maximum clock speed of 780 MHz if I buy the high-speed grade parts; if I want 2...
by zombiess
Jun 10 2021 6:03pm
Forum: Motor Technology
Topic: Non-silicon and/or soft-switched controller topologies?
Replies: 63
Views: 1852

Re: Non-silicon and/or soft-switched controller topologies?

Quick question; did you get those numbers with an external heatsink on the transistors you were switching? That is the one really annoying thing about SMT power parts; the heat path into the board is often the best path for device heat. I'm kind of tempted to try to make a heat pipe to sit on top o...
by zombiess
Jun 10 2021 12:46pm
Forum: Motor Technology
Topic: Non-silicon and/or soft-switched controller topologies?
Replies: 63
Views: 1852

Re: Non-silicon and/or soft-switched controller topologies?

I've done a lot of empirical testing on power dissipation in PCBs for my own designs and I'm pretty sure you will need to reduce your power dissipation to work at the size you are talking about, or figure out a better way to get rid of the heat / produce less of it. I've found that a 4 layer 1.2mm t...
by zombiess
Jun 09 2021 2:11pm
Forum: Motor Technology
Topic: Non-silicon and/or soft-switched controller topologies?
Replies: 63
Views: 1852

Re: Non-silicon and/or soft-switched controller topologies?

Thanks for the advice! I found the old thread about distributed controllers from 2014 where laminated busbars and the details of how to do clever low-inductance things came up (https://endless-sphere.com/forums/viewtopic.php?f=30&t=55641), and reorienting the half bridges slightly and using lam...
by zombiess
Mar 29 2021 6:19am
Forum: Motor Technology
Topic: New ground-up ESC - MESC_FOC_ESC
Replies: 178
Views: 10238

Re: New ground-up ESC - MESC_FOC_ESC

I'm curious to see how well it performs thermally. I've worked with some power SO8 devices in SMPS designs and found thermal management to be challenging when using a PCB as a heat transfer medium. I could only manage about 5W of waste heat produced mostly by 2x SO8's on a 45x45mm board area with a ...
by zombiess
Mar 19 2021 4:57pm
Forum: Motor Technology
Topic: New ground-up ESC - MESC_FOC_ESC
Replies: 178
Views: 10238

Re: New ground-up ESC - MESC_FOC_ESC

External Cgs is a very strong tool against miller. I use it most of the time, and always place the footprint. Just keep in mind the extra avg current on the gate driver and that the cap tolerance is really bad compared to the typ 1% resistor. I also agree adding some Cgs can work wonders, but it ca...
by zombiess
Mar 08 2021 1:02am
Forum: Motor Technology
Topic: 10kW BLDC motor controller up to 90V and 200A with sensorless FOC - build thread
Replies: 63
Views: 3318

Re: 10kW BLDC motor controller up to 90V and 200A with sensorless FOC - build thread

Peters, you did a nice job working with only 2 layers. My first design was only 2 layers and with parallel devices it was a mess to figure out. Did it take you more than one try?
by zombiess
Mar 04 2021 8:05pm
Forum: Motor Technology
Topic: 10kW BLDC motor controller up to 90V and 200A with sensorless FOC - build thread
Replies: 63
Views: 3318

Re: 10kW BLDC motor controller up to 90V and 200A with sensorless FOC - build thread

The gate driver he has detects desat at 6.5V. Peters hasn't said what FETs he's using (has he?) but I'm going to assume that 2to247s have an Rdson of about 1-2mohms. So the desat kicks in at 3-6.5kA. I don't think 1) the FETs will be able to break this current 2) his battery can supply that current...
by zombiess
Mar 04 2021 2:11pm
Forum: Motor Technology
Topic: 10kW BLDC motor controller up to 90V and 200A with sensorless FOC - build thread
Replies: 63
Views: 3318

Re: 10kW BLDC motor controller up to 90V and 200A with sensorless FOC - build thread

So what do we actually expect to cause desat of these MOSFETs? I'm 100% behind: Over current Over voltage (though this seems routinely overlooked despite being the single biggest cause of FET death) Shoot through protection/hardware dead time Fuses before the ESC Inrush limiters Défensive coding Wa...
by zombiess
Mar 03 2021 11:42am
Forum: Motor Technology
Topic: 10kW BLDC motor controller up to 90V and 200A with sensorless FOC - build thread
Replies: 63
Views: 3318

Re: 10kW BLDC motor controller up to 90V and 200A with sensorless FOC - build thread

I don't understand a lot of the choices, the avago gate drivers with 5kV isolation, IGBT drivers with all the miller desat stuff when you're using MOSFETs, isolation everywhere for 90V... But it's fascinating. It would be really unlucky if it didn't work. Hopefully it's bulletproof This is the way....