Search found 2870 matches

by zombiess
Aug 01 2020 9:11am
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 452
Views: 98453

Re: Axiom: a 100kW+ motor controller

personally, I start by figuring out the waste heat I need to dissipate in the worst case scenario. I usually solve this iteratively in excel, then multiply that times a safety margin. I usually assume ambient temp is around 40-50C to add some safety buffer, but this varies. If you have a spec to mee...
by zombiess
Jul 23 2020 6:28pm
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 47
Views: 2570

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

Thanks for the note on the double pulse test. I attempted to pulse from within VESC firmware at some point but it didn't work at that time, so I just went on testing under load and monitoring the gate signals and the DC link. Making measurements on a running motor generally produces non repeatable ...
by zombiess
Jul 22 2020 6:30pm
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 47
Views: 2570

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

I haven't gotten to measuring the inductance on the boards but signals look good under load. SMD power parts on FR4 would likely be a bad idea, but it works great so far on Aluminum substrate. Yeah, SMD on FR4 doesn't seem like a good idea. My curiosity is in the loop area created by using a single...
by zombiess
Jul 22 2020 12:35am
Forum: Motor Technology
Topic: Gate driver design with TD350E
Replies: 4
Views: 269

Re: Gate driver design with TD350E

The regulator comment was something I've been told. You probably won't have any issues, but based on who told me I'm taking his word for it that oscillations can happen. It's generally bad practice to run a trace into your isolation zone. It would be better to route that trace around the front, even...
by zombiess
Jul 20 2020 10:37pm
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 47
Views: 2570

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

I went through multiple iterations with early ones using TO-247s but ended up with TO-Leadless mosfets on a single layer Al substrate to kill two birds with one stone: reduce parasitic inductance and provide direct heat dissipation interface via the board to the heatsink. I've never had much love f...
by zombiess
Jul 17 2020 9:34pm
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 47
Views: 2570

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

What does your fault detection circuit look like? Mine currently looks like holding the fault pin on the mcu high via a pull up. LOL! That's the same method I use when I generate a fault, pull the MCU pin low. I have added an additional layer of hardware fault detection which operates by pulling th...
by zombiess
Jul 17 2020 8:18pm
Forum: Motor Technology
Topic: Gate driver design with TD350E
Replies: 4
Views: 269

Re: Gate driver design with TD350E

If you are going to be switching MOSFETs and <200V, I don't see an advantage to the 2 level turn off function. My suggestion is to set it up, but not populate it. In my latest design I left it out, however that was a mistake since I plan on using IGBTs at some point, so my next revision will have it...
by zombiess
Jul 17 2020 10:19am
Forum: Motor Technology
Topic: low inductance output stage contruction
Replies: 208
Views: 24792

Re: low inductance output stage contruction

bdj,

We should start a new thread about the gate driver design and then provide a link to it here. That way it will be easier for people to find the information in the future. PM me after you start the new thread.
by zombiess
Jul 16 2020 10:32pm
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 47
Views: 2570

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



I upgraded the dyno and set it to torture mode.
180A phase current into a very high load. The FOC algorithm help up fine.
by zombiess
Jul 16 2020 12:15pm
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 47
Views: 2570

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

Hey mystamo, I haven't made this current design open source. I'm not sure if I'm going to take this down that road or not. It might be worth while to get more people interested in my higher power designs I have in progress (+1000A). My VESC controller is similar to the Axiom schematic, but I've modi...
by zombiess
Jul 14 2020 9:14am
Forum: Motor Technology
Topic: low inductance output stage contruction
Replies: 208
Views: 24792

Re: low inductance output stage contruction

STGAP2S looks like a isolated driver with a miller clamp. My personal preference is to have desat and fault output so i can detect problems and shutdown. If I was doing a low power design i would consider using it. I have been considering using an Infineon 2ED020I12-F2 in a design. But I've never pl...
by zombiess
Jul 14 2020 1:39am
Forum: Motor Technology
Topic: low inductance output stage contruction
Replies: 208
Views: 24792

Re: low inductance output stage contruction

Thank you both for very detail explanations. I will build proposed gate driver. Zombiess is everything what is needed in this post https://endless-sphere.com/forums/viewtopic.php?f=30&t=58341 ? Parralel I will work on redesign on my gate driver and report findings. It's been so long, I don't rememb...
by zombiess
Jul 14 2020 1:32am
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 47
Views: 2570

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

I finally found a dyno that can take the power. Dual ME-0913. I shorted out the phase leads on the load motor, so at this point the controller is pretty much running into a locked rotor scenario at 200A phase. This is the worst case scenario for a controller. These motors are 15uH and 6.8mOhm. If I ...
by zombiess
Jul 12 2020 2:53am
Forum: Motor Technology
Topic: low inductance output stage contruction
Replies: 208
Views: 24792

Re: low inductance output stage contruction

I reckon Zombiess's new design is the best practice for gate driver connection, because the gate circuit junction on the FET legs is as close as possible to the case, that produces the smallest bumps and dips we talked above (otherwise 2-3V bigger spikes can be induced on a 3-5mm long S pin at high...
by zombiess
Jul 12 2020 2:44am
Forum: Motor Technology
Topic: low inductance output stage contruction
Replies: 208
Views: 24792

Re: low inductance output stage contruction

Zombiess I read posts you suggested. Concerning the dead time explanation with counting for propagation times and delays through the nodes and connections, this is math approach concerning data from datasheets, but for first steps will it be also valid by looking at scope Vgs from hi and low fets a...
by zombiess
Jul 10 2020 6:15pm
Forum: Motor Technology
Topic: low inductance output stage contruction
Replies: 208
Views: 24792

Re: low inductance output stage contruction

I see from datasheet of TD350E that miller clamp can be used in configuration to short G-S when fet is turned off. In reality are there any spikes, bumps, disturbances.. on Vgs voltage or it really looks like flat line near zero V? The amount of induced voltage on the gate trace is dependent on how...
by zombiess
Jul 10 2020 9:04am
Forum: Motor Technology
Topic: low inductance output stage contruction
Replies: 208
Views: 24792

Re: low inductance output stage contruction

I'll second Peters recommendation for 1000ns dead time as a starting point and that the waveforms are good enough. They will never be picture perfect. Just be aware that as you go up in current, the layout becomes MUCH more critical to success. My TDE350 gate driver design requires 800ns to ensure e...
by zombiess
Jul 09 2020 5:49pm
Forum: Motor Technology
Topic: low inductance output stage contruction
Replies: 208
Views: 24792

Re: low inductance output stage contruction

Very nice video with lot of details. Can you try a speed step response from slowest speed to highest to be able to simulate high load and measure current and also Vds overshoot? I suppose that would have highest impact on Vds overshoot? I'm not quite sure what you are asking for. In the video I go ...
by zombiess
Jul 09 2020 5:46pm
Forum: Motor Technology
Topic: low inductance output stage contruction
Replies: 208
Views: 24792

Re: low inductance output stage contruction

bdj, where are you located? You gate driver layout looks like it is lacking good ground planes. Having test points on a gate driver is also something I was taught to avoid as they increase the chances of picking up noise. Gate drivers are one of the most difficult pieces to get correct as they are v...
by zombiess
Jul 09 2020 1:31am
Forum: Motor Technology
Topic: low inductance output stage contruction
Replies: 208
Views: 24792

Re: low inductance output stage contruction

try to change it to 1-1.5us with a 50-100ohm turn-on resistor, and keep the 10nF Cgs also at the FET. But it increases the current transition time and the switching loss. I've been told that high value gate resistors aren't the greatest idea. I think this was discussed in more detail way back in my...
by zombiess
Jul 09 2020 12:51am
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 47
Views: 2570

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

LcJCTB-6k2c I setup a large out runner motor, a 120100 70KV motor with 9uH inductance. I do a bit of a walk through and scope shots during the video. Sorry it's shaky, I need to get a stabilizer and do better planning if I'm going to do this type of video. This was done off the cuff with no plannin...
by zombiess
Jul 07 2020 6:38pm
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 47
Views: 2570

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

Inductance measurement error is a known vesc issue on 3rd party hardware. I guess it works better the faster the powerstage switches, and at lower f_sw I get more accurate results. Shaman was also concerned about this, and many people would be interested on fixing this issue. I'm still a total noob...
by zombiess
Jul 07 2020 12:45am
Forum: Motor Technology
Topic: VESC based +200A powerstage with 200V MOSFETs (videos of it in action)
Replies: 47
Views: 2570

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

I managed to get this beast running tonight without much issue in FOC. It's a controller killer at 8uH inductance phase to phase on 4gauge leads. 70KV. I cant rally load it for more testing, but i wanted to see if it would work. The only setup I have which I can load uses 2 older Montenergy ME-0901s...
by zombiess
Jul 06 2020 10:34pm
Forum: Motor Technology
Topic: low inductance output stage contruction
Replies: 208
Views: 24792

Re: low inductance output stage contruction

I am not sure if my gate driver with quick and dirty layout can have big influence on overshoot. Gate driver design is THE MOST IMPORTANT PART of a successful build. There are several rules to follow, the hard part is obeying them. You might find some of the info in this thread about one of my prev...