Search found 955 matches
- Wed Mar 01, 2023 10:19 pm
- Forum: Inverters / Motor Controllers
- Topic: In one housing inverter and motor capacity of 160 kilowatts
- Replies: 1
- Views: 604
Re: In one housing inverter and motor capacity of 160 kilowatts
Drive units like this are great. For DIY'ers, salvage Tesla drive units usually provide more power for a much lower cost, but if I were embarking on a commercial design, I would definitely try to source a drive unit like this. You may also want co check out https://webshop.swindonpowertrain.com/inde...
- Tue Feb 28, 2023 6:11 pm
- Forum: General
- Topic: New MOT rules
- Replies: 9
- Views: 1037
Re: New MOT rules
This seems like nothing but a vague suggestion by somebody looking for opinion. I'm broadly in favor of such addition tests. However, realistically, in my opinion the only way to "test" an EV battery is going to be similar to a PAT test. Mostly a visual inspection, looking for worn / fraye...
- Sun Feb 26, 2023 12:22 am
- Forum: Battery Managment (BMS)
- Topic: Gerber files 4 Tesla BMS
- Replies: 2
- Views: 5474
Re: Gerber files 4 Tesla BMS
Most of these boards come from companies who are not very good at sharing their designs, and as such the gerbers are not available. I had a quick look and found this, but it doesn't match up with the other boards, so I'm not sure if it's useful: https://github.com/relectric-car-team/pcb-tesla-cell-tap
- Tue Feb 21, 2023 8:08 pm
- Forum: Inverters / Motor Controllers
- Topic: Current control of induction motors
- Replies: 192
- Views: 32024
Re: Current control of induction motors
[OLD VERSION REMOVED]
- Tue Feb 21, 2023 7:00 pm
- Forum: Tesla
- Topic: SDU parameter tuning - major failure - can't select drive gear
- Replies: 36
- Views: 3908
Re: SDU parameter tuning - major failure - can't select drive gear
Regarding the TVS approach. could you give some more information on how you dimensioned the diodes and resistors? Don't overthink it. Just make sure the contactors never open unless the vehicle is idle. tripode=1 should be all you need. There are some extreme edge cases like blowing a low voltage f...
- Tue Feb 21, 2023 9:15 am
- Forum: Inverters
- Topic: Car inverter as a 3 phase inverter ?
- Replies: 26
- Views: 13187
Re: Car inverter as a 3 phase inverter ?
I was under the impression the output of a Prius Gen2 and Gen3 inverter was a SPWM and am now reading might not be as clean as I was thinking. I may be thinking that way due to reading via controlling using the openinverter. Either way, filtering would be required... though less based on the SPWM a...
- Tue Feb 21, 2023 8:57 am
- Forum: Tesla
- Topic: Tesla front SDU oil - Mobil SHC 629 alternatives [SOLVED]
- Replies: 7
- Views: 2851
- Mon Feb 20, 2023 8:47 pm
- Forum: Inverters / Motor Controllers
- Topic: Current control of induction motors
- Replies: 192
- Views: 32024
Re: Current control of induction motors
So, after lots of tuning (and only minor code changes) I would like to release what will hopefully be the final version for now. This version enables regen! It's still not as polished as I'd like, but it seems to work. Attachments: stm32-sine.bin - Version 5.26.X tesla-sdu-performance-slipmin.json -...
- Sun Feb 19, 2023 11:30 pm
- Forum: General
- Topic: Best sine parameter to vary for traction control?
- Replies: 27
- Views: 3109
Re: Best sine parameter to vary for traction control?
The only parameter to update to directly reduce torque is throtmax. This is used as part of the throttle calculation at 100Hz. There are two problems here though: 1) Throtmax won't have any impact until it's less than the actual throttle value (potnom). This probably isn't a huge issue, traction is ...
- Sun Feb 19, 2023 4:25 pm
- Forum: Inverters / Motor Controllers
- Topic: Current control of induction motors
- Replies: 192
- Views: 32024
Re: Current control of induction motors
Big success. I now have stable regen. I didn't achieve this by any particularly clever code, just by limiting various slew rates. regen-success.png Specifically: 1) I introduced separate gains for positive current correction vs negative current correction. This allows me to tune the negative gain t...
- Sat Feb 18, 2023 7:16 pm
- Forum: Inverters / Motor Controllers
- Topic: Field oriented control of induction motors
- Replies: 71
- Views: 12849
Re: Field oriented control of induction motors
What's the benefit be of using FOC for induction motors versus just the plain Sine algorithm? I'll be running an induction motor (nothing fancy like a tesla, a forklift motor). Wondering if/how this might affect me. In theory, a correctly implemented FOC algorithm has three main benefits: 1) More e...
- Sat Feb 18, 2023 6:00 pm
- Forum: Inverters / Motor Controllers
- Topic: Current control of induction motors
- Replies: 192
- Views: 32024
Re: Current control of induction motors
A while back, I experimented with some code to graph the in-phase (real) and out-of-phase (reactive) current. Looking again at that data I am convinced it is useful for a couple of reasons. Firstly, looking at the following 0-60 graph it can clearly be seen that as speed increases, the ratio between...
- Sat Feb 18, 2023 4:16 pm
- Forum: Inverters / Motor Controllers
- Topic: Field oriented control of induction motors
- Replies: 71
- Views: 12849
Re: Field oriented control of induction motors
How about coupling the two motors together. One on MG1 the other on MG2 and run the pair as a dyno ;) This is seeming like it might be the best idea. Probably easiest to do with two identical sizes motors, will make mounting and coupling a lot simpler. I am putting this FOC on hold for now as it ki...
- Sat Feb 18, 2023 1:24 am
- Forum: Inverters / Motor Controllers
- Topic: how to find out the correct FWEAK without knowing the parameters of the ACIM motor?
- Replies: 29
- Views: 2818
Re: how to find out the correct FWEAK without knowing the parameters of the ACIM motor?
I lowered the fweakstrt to 0 a lower value of fweak will give you more current fweak and fweakstrt control the speed at which 100% voltage is applied. Set one of them to zero and you will get 100% voltage at zero speed. That's certainly a quick way to destroy your controller, sorry :( It's not clea...
- Wed Feb 15, 2023 7:59 pm
- Forum: Inverters / Motor Controllers
- Topic: Current control of induction motors
- Replies: 192
- Views: 32024
Re: Current control of induction motors
I did some more regen testing today, this time using higher current targets and lower slip as proposed. This does lead to a substantial improvement in stability! Regen seems to work and remains stable. road-regen-almost.png However, one problem remains. When reducing regen (ie moving from regen to z...
- Wed Feb 15, 2023 12:35 am
- Forum: Inverters / Motor Controllers
- Topic: how to find out the correct FWEAK without knowing the parameters of the ACIM motor?
- Replies: 29
- Views: 2818
Re: how to find out the correct FWEAK without knowing the parameters of the ACIM motor?
In therory, fweak is the frequency at which the motor is rated to run at your full battery voltage. Here are some tings to consider: 1) Rated parameters of motors are more like suggestions than exact values, so don't worry about getting it exact. 2) That a lower value of fweak will give you more cur...
- Tue Feb 14, 2023 7:44 pm
- Forum: Inverters / Motor Controllers
- Topic: Field oriented control of induction motors
- Replies: 71
- Views: 12849
Re: Field oriented control of induction motors
I've been donated another 1kW motor with a chain sprocket on it. This one might be more practical to attach a load to ![Smile :)](./images/smilies/icon_e_smile.png)
![Smile :)](./images/smilies/icon_e_smile.png)
- Tue Feb 14, 2023 7:11 pm
- Forum: Inverters / Motor Controllers
- Topic: Current control of induction motors
- Replies: 192
- Views: 32024
Re: Current control of induction motors
I found myself thinking about regen again today, and I think I have an idea how to prevent the unpleasant current spikes. It's my suspicion that all along I've been trying to set the current too low. Looking at this chart, we can see that as we switch into regen and set slip negative, we get a risin...
- Mon Feb 13, 2023 11:15 pm
- Forum: Inverters / Motor Controllers
- Topic: Field oriented control of induction motors
- Replies: 71
- Views: 12849
Re: Field oriented control of induction motors
Slightly envious of your test setup too ;) I really like this setup. Thanks to johu for providing the STM32 board! The Prius inverter and industrial motor were quite cheap (about £80 each). The battery and contactors were leftover from my car build. I'd still like to find a way to test with a load....
- Mon Feb 13, 2023 8:00 pm
- Forum: Inverters / Motor Controllers
- Topic: Field oriented control of induction motors
- Replies: 71
- Views: 12849
Re: Field oriented control of induction motors
Are you referring to equation (11) here? If so that is just for the steady state, where dPsir/dt = 0. Under non-steady state conditions I think you need the other term too. Nope, referring to Phir in equation 9 - the one that's self-referential. I'm suggesting that if you replace Phir with... itsel...
- Mon Feb 13, 2023 4:08 pm
- Forum: Inverters / Motor Controllers
- Topic: Field oriented control of induction motors
- Replies: 71
- Views: 12849
Re: Field oriented control of induction motors
Had a look at this but still can't work out how Lm could cancel :? Here are my calcs in case they are of any use? Thank you for going through this. On the very first line of your calculations, you have "-Psir/Tr". My argument was based on the assumption that Lm and Id are both factors of ...
- Mon Feb 13, 2023 3:45 pm
- Forum: Inverters / Motor Controllers
- Topic: Field oriented control of induction motors
- Replies: 71
- Views: 12849
Re: Field oriented control of induction motors
Here's another short demo of the motor running on the bench after some tweaking of settings.
- Mon Feb 13, 2023 12:27 pm
- Forum: Inverters / Motor Controllers
- Topic: Field oriented control of induction motors
- Replies: 71
- Views: 12849
Re: Field oriented control of induction motors
So, rather late last night I wrote a simpler FOC implementation. The full code is here: https://github.com/catphish/stm32-sine/blob/foc-sine-basic/src/pwmgeneration-sine.cpp First we fetch some settings. slipconst is a time constant. It's a combination of motor parameters and the PWM frequency. It d...
- Sun Feb 12, 2023 10:47 pm
- Forum: Inverters / Motor Controllers
- Topic: Field oriented control of induction motors
- Replies: 71
- Views: 12849
Re: Field oriented control of induction motors
Anyway... proposed code. Not yet tested! https://github.com/catphish/stm32-sine/commit/c6ac4a6cb652415e0402ae42a34603a58137cceb#diff-b8914fe3a0942d8ed9dfd6f4996301481a1a4a1ec65b8467a5733807ac931d26 Going back over the code, I feel like this might work in steady state, but there's one aspect that co...
- Sun Feb 12, 2023 10:30 pm
- Forum: Inverters / Motor Controllers
- Topic: Field oriented control of induction motors
- Replies: 71
- Views: 12849
Re: Field oriented control of induction motors
Need to write it out to be sure but if the rotorFlux calculation is written on a single line rather than two them Lm isn't common to both terms and so won't cancel when calculating slip. Or am I misunderstanding the question? I'm not sure how best to explain, but I'm thinking that Lm multiplies the...