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Forum Index : Electronics : Silicon Caarbide
| Author | Message | ||||
| davros Newbie  Joined: 24/02/2025 Location: CanadaPosts: 17 |
Ran across this vid the other day : https://www.youtube.com/watch?v=kzuOezZ_quI Without much concern or schematics he just swapped the output devices and seems to have made some gains. Thoughts? |
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| Solar Mike Guru  Joined: 08/02/2015 Location: New ZealandPosts: 1164 |
Those SIC devices are more efficient than the existing IGBT's especially at higher voltages, as in the case in that video, so the efficiency will be better; however SIC devices generally require a higher gate switching drive voltage to get that better efficiency, so just swapping out the IGBT's for SIC may not make a huge difference, SIC's also cost a lot more than IGBT's. It is interesting that the alcheapo Chinese unit in the video uses "old" but less expensive tech; for instance the IGBT drivers are all FOD3120 opto isolated drivers, these are quite old now, but cheap. What is great to see there was every IGBT had its own opto driver chip, gives confidence in their product design. Cheers Mike |
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oreo Senior Member  Joined: 11/12/2020 Location: CanadaPosts: 115 |
The inverter in the video is quite unlike the inverters built on this forum. In the video, he is replacing high voltage IGBT's with Silicon Carbide FETs. Silicon Carbide Fets have voltage ratings ranging from 400v to 2000v, while most of us are using FETs rated at 80v. So an interesting new technology, that would probably be applicable to say a high voltage MPPT, but not the LF inverters we build here. On another note, I noticed that the guy up in port Hope(near you) is selling more A123 battery systems. For $300 you get a box with 16x 756w rated packs (plus HV DC relays, fans, heaters, wire etc). They are very used but you can still net ~ 10KW with 16 packs. Last time I did this I got around $120 after recycling the unused steel, copper and cast aluminum. So that works out to $200cad for 10kw (plus a bunch of labour). BAE Battery units On the downside, these are 36v packs, which is why I decided to make my system 72v rather than the more normal 48v. Greg |
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| analog8484 Senior Member Joined: 11/11/2021 Location: United StatesPosts: 155 |
As the video shows, direct replacement of IGBT with SiC MOSFET in a circuit designed for IGBT only provides small gains at a much higher cost. Not really worthwhile. However, in a properly designed circuit topology (e.g. dual active bridge) for SiC MOSFET that is switched at a much higher frequency (e.g. 10x+) compared to IGBT inverters there could be significant power density gains due to the size, weight and cost reduction of other components (e.g. inductors, transformers, etc.). Unfortunately, none of it is DIY friendly. Edited 2025-07-23 02:33 by analog8484 |
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| davros Newbie Joined: 24/02/2025 Location: CanadaPosts: 17 |
Interesting, 123A cells, wonder how old they are, this would have been build before the bankruptcy the first time? That becomes quite a project. Focusing on finishing my small build of LEV60's (x16) which I brought back while on southern vacation. Not having to ship across borders and catching the last price drop made them attractive $22/ea. Given their reputation for high current hoping to end up with something that can deal with a well pump start. |
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| oreo Senior Member Joined: 11/12/2020 Location: CanadaPosts: 115 |
I have gotten these A123 based packs on 2 occasions. The first time the cells were all ANR26650M1A's. The second time had some cell packs with ANR26650M1B's. So yes, older and newer cells. I see that Battery Hookup have these LEV60F's. Is that where you got them? I notice some chatter about the charge voltage being slightly lower for LEV60F's then normal LIFEP04 cells. Is this really the case? Greg |
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| davros Newbie Joined: 24/02/2025 Location: CanadaPosts: 17 |
Yes Batteryhookup was the source. Spec sheets are scant. I did find one that was a joint Yuasa /Lithium Energy Japan sheet stating 3.5v. Most others are partial copies of the above. I think Mitsubishi was using them in vehicles. I wonder if since the intended use is high current peaks the lower spec prolongs life? Is the chemistry really different? Who knows. Maybe since the application is automotive you have mechanics instead of electrical engineers, thus the single digit behind the decimal? Construction is definitely robust and heavy.I was hoping this pack would be lighter than my EVE105 but it is not going to be the case. |
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