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Forum Index : Electronics : 15KW Inverter Help
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| alanjfritz Newbie  Joined: 09/07/2019 Location: United StatesPosts: 4 |
Okay guys, I have watched and read all I can and am having some issues now. Let me lay it all out and any tips or pointers would be helpful..... I own a Chevy Volt, I have tapped into the main battery and can extract 320-380V from the main battery, my limit is 118KW from the system. I tested this with a load bank intended for aircraft.... The system keeps up and will allow me to drain the battery, keeping the battery cool, and start the engine to attempt to recharge the battery.... All good so far..... The genny in the RV is going out, since I tow the car with me it makes sense to utilize that power...... my thought is to use one of the egs002 inverter boards to build an inverter since none are commercially available (or more expensive than the car or RV) how can I make this a reality. Goal is Split phase 240V (120-0-120) 60HZ 50 Amps (Matches RV wiring) My mossfets keep exploding like gernades at my 240V DC test with a light bulbs as the load... (Fused 240V, through welder diodes to get DC) I'm on my 8th or 9th EGS002 driver board, I have been buying 5 at a time...... I need help selecting parts and apparently a little more instruction on how to build the H-Bridge.... Someone point a finger towards 1) component selection 2) where to get materials to make the toroidal transformer 3) weather i'm nuts or not.....(Joke really, I just need to be very careful) |
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| alanjfritz Newbie Joined: 09/07/2019 Location: United StatesPosts: 4 |
Power Analysis; Over the past year, since the armature bearings started going out on the generator I installed current sensors to determine current load requirements. During the summer, with all 3 AC running there is a steady load of 6.8KW With the electric Water heater it jumps to 8.4KW for a half hour or so. evening loads are very modest, Averaging 1.8KW. During the winter, the loads are small. Average load is 0.8KW with occasional jaunts to 2.2KW while cooking and running various appliances. From my analysis I calculate the flowing power requirements; AC1: 4KW run / 16KW Start AC2: 0.8KW Run / 2.2KW Start AC3: 2.2KW Run / 6.9KW Start Water Heater: 1.44KW Battery Charger (12V System): 2.4KW (Max) Washer Dryer: 6KW (Max) (Special Notes) Refrigerator: 0.6KW Run / 1.5KW Start Misc Entertainment (TV, Radio, Stereo): 0.5KW Concussion: The inverter must sustain a load of 9KW with sustained overloads to 12KW (30 Minutes) And a starting capacity of 16KW Complications: The RV has a split phase electrical system. In the worst case the legs have been off by as much as 30A (2.4KW) The Washer/Dryer Combo is the worst for this, Using 240 for the heating elements and one leg for both the washer motor and the dryer motor.... I have spent some time evening out the balance but some tasks inevitably cause a imbalance in the phases. Since I can not think of a way for any of the EGS002 Modules to account for this I believe Arduino may rescue me. Keeping the phases in balance and creating 2 - 6KW inverter "Halves" kept in check and balance by the Arduino Since my input voltage is higher than the output do I need a transformer to step it down or will SPWM acomplish this? Edited 2019-11-17 23:59 by alanjfritz |
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mackoffgrid Guru  Joined: 13/03/2017 Location: AustraliaPosts: 460 |
Hi Alan - Split phase, I'll pass on that one' - SPWM should manage that voltage pretty well I would have thought. - You will probably want to use IGBTs instead of mosfets. Be very careful of your creepage and isolation. Many PCBs available to SPWM are designed for 48v so are not so concerned about these issues. Have a look at Poida's work on nano inverter. Cheers Andrew |
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| alanjfritz Newbie Joined: 09/07/2019 Location: United StatesPosts: 4 |
Fortunately, The power bank i'm using requires complete isolation from ground. If there is more than 2M Ohms of continuity between battery Positive, Or battery Negative the relay opens. I'm sure this will be an issue later. I thought/assumed Mosfets were the only option for these currents. Every inverter I have seen uses them and I just assumed it was the best or only option. I will research some on IGBTs...... |
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| mackoffgrid Guru Joined: 13/03/2017 Location: AustraliaPosts: 460 |
As you get above 100v IGBTs tend to become more popular. They have the reputation of being a lot more robust. |
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| alanjfritz Newbie Joined: 09/07/2019 Location: United StatesPosts: 4 |
Finally an update. The cost of these IGBT's are steep. i'm finding trouble creating an h-bridge that can be driven by an Arduino. at these voltages, and the fact i am operating my experiments inside a closed cabinet. does anyone have any suggestions on creating an h-bridge that cant short its inputs t ground when the Arduino is fired up? |
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| BenandAmber Guru Joined: 16/02/2019 Location: United StatesPosts: 961 |
That is a lot of power consumption I've Been Told over and over again by the experts it is a lot cheaper to lower your power needs then try to build a system that big Have you looked into mini splits yet I've been seeing them at incredibly low prices I don't know if they're any good but very low prices It may be way cheaper to run a generator when you have Peak loads Warpspeed and wiseguy have been talking a little bit about high voltage systems Thay make incredible work of art Electronics They are very careful about giving advice along with pretty much everyone else on here You can take what they say to the bank along with several other people on this site I have a post I think it's called inverters and other things it has a few high voltage inverters along with systematics If I can help you locate a part or donate a part to help you achieve your goal just let me know Give it a little bit of time for a response on here I think people's pretty busy in Australia right now lots of fires and other things going on That's where a lot of the experts live You're going to come to find that Australian people are highly intelligent independent resourceful and all around good quality people Thay bend over backwards to help you expecting nothing in return You may or may not like their advice but it'll be the best advice you can get If you don't mind me asking where you from I'm curious and it will help others answer your question better And another thing the ratings like me being a guru does not reflect your abilities or skills it goes off who posts the most I guess you could say I'm a blabbermouth lol Edited 2020-02-20 10:33 by BenandAmber be warned i am good parrot but Dumber than a box of rocks |
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| brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Ben and Amber ..... Certainly a couple of the nice ,intelligent forum members. You strike me as being the type of posters that I "just have to read" contributors. I remember you both being so polite and never afraid to ask the questions . and aways willing to help with spare parts . Nice forum people, thanks. Bruce Bushboy |
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| BenandAmber Guru Joined: 16/02/2019 Location: United StatesPosts: 961 |
Thanks for the kind words Bruce you are the exact same kind of person This site is full of really good people it's been a blessing to me and my wife's life Just hope I get a chance to pass it on be warned i am good parrot but Dumber than a box of rocks |
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| Pete Locke Senior Member  Joined: 26/06/2013 Location: New ZealandPosts: 178 |
IGBT's can be found in redundant VSD's (VFD's) in modular or discrete (discrete in old units) with some impressive power ratings. New (modular) units can be had for $150-00 like These or new discrete ones like these here . The free old ones from used VSD's are the best if you ask nicely  .Cheers Pete'. |
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Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 961 |
Interesting setup, if I had A high voltage battery bank I would certainly be tempted to build an inverter to run on it, and the parts count would also be very low compared to 48v or 24v. I'm no expert on these but will try to explain a little, the grid tie inverters and the bigger High Frequency inverters that I have opened up to look inside, they all use opto isolated gate drivers on the Maine inverter to drive a single large IGBT per leg of the H-Bridge, the IGBT's are usually 700 volt or so with a built in body diode, without the diode it will likely go bang. There are many running this way, there may be some with several devices per leg but I have not seen one yet, more likely they use much more powerful IGBT blocks. That's about all I know about it ATM. Not much help I guess, but as I said, I have not built one for that High voltage. Best of luck with it. Edited 2020-02-20 20:28 by Revlac Cheers Aaron Off The Grid |
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| noneyabussiness Guru Joined: 31/07/2017 Location: AustraliaPosts: 506 |
The egs002 board was actually designed for 400v, check the datasheet on it, and the ir2110/3's are happy to run upto 600v, so as long as everything is put together properly, it will love it... most modern small form factor (read cheap) inverters boost the battery voltage to 400 odd volts the chop it up to a sinewave so its a common occurrence and there is heaps written on it. To get " free " high voltage igbt/mosfets, start with simple power supplies from the dump, most will have 1 or 2 , might not be " the best part " for what you want, but a cheap easy way to test you design.. Caveats , igbt's generally are tougher as long as you compensate for the shortfalls, eg. No intrinsic body diode.. but mosfets are no pushover ether here... i would suggest if not already done, do a HEAP of reading on mosfet / igbt driving application notes before deciding. All the major brands have them.. I think it works !! |
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| BenandAmber Guru Joined: 16/02/2019 Location: United StatesPosts: 961 |
I have 5 or 10 computer power supplies If there's anything inside of them you can use I've been trying to do the impossible and get rid of everything I don't use Of course there a couple weeks ago when I was at the recycling Center i saw two matching UPS Transformers Had to grab them even though I had two sets of them already at home That makes me three matching sets I had no use for the ones i already had I wish toroids would come around like that!!! Anything I have that I'm not using is free just send me a message the only thing is you would have to pay shipping that goes for anybody on this site By the way that includes the 465 scope one half of the Screen Works when you have it generating a square wave you can see the square wave on one side of the screen It would give me great joy to see someone on here fix it and find a home for it it is free along with anything else just pay shipping the good people one here told me to pass it on when they helped me I am trying my best to do that If you private message me I should see it It can be done discreetly just make sure to let me know that's how you want it I've been there and I'll respect your wishes Edited 2020-02-22 04:03 by BenandAmber be warned i am good parrot but Dumber than a box of rocks |
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