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Forum Index : Electronics : 15KW Inverter Help

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alanjfritz
Newbie

Joined: 09/07/2019
Location: United States
Posts: 3
Posted: 02:02am 16 Nov 2019
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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)
 
alanjfritz
Newbie

Joined: 09/07/2019
Location: United States
Posts: 3
Posted: 01:53pm 17 Nov 2019
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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
 
mackoffgrid

Guru

Joined: 13/03/2017
Location: Australia
Posts: 439
Posted: 07:26pm 17 Nov 2019
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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
 
alanjfritz
Newbie

Joined: 09/07/2019
Location: United States
Posts: 3
Posted: 08:13pm 17 Nov 2019
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  mackoffgrid said  

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.



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.

  mackoffgrid said  
-  You will probably want to use IGBTs instead of mosfets.


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......
 
mackoffgrid

Guru

Joined: 13/03/2017
Location: Australia
Posts: 439
Posted: 08:53pm 17 Nov 2019
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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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