How to build your own off grid inverter

Topics concerning inverters for on or off grid use. DIY and OEM.
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GaryHo
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How to build your own off grid inverter

Post by GaryHo »

I noticed some time ago Damien asked me to share what I have done, unfortunately, I did not have email notification setup and had not been here for a long time.

I have built several of these inverters and sold many PCBs to others to do the same via https://www.thebackshed.com

For around $500USD you can build a very robust 8KW or 4KW CONTINUOUS 48V full sinewave inverter. I have been running my house off the 8KW version for 6 years now. We have a big screen TV, Dishwasher, washing machine, clothes dryer, water pumps, induction cooktop, computers running 24/7 and even a 10KW (cooling capacity, 3KW input) airconditioner that is used on hot sunny days here in Australia. All this is powered from 14KW of PV panels which charge a 775AH 48V FLA forklift battery. I know many of you will scream about Lithium etc but it was by far the cheapest battery when I bought it 4 years ago.
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If people are interested I can upload PCB files, Arduino code etc, I used 2 Aerosharp 3KW grid tie inverters for the toroidal transformer by unwinding and rewind 2 and combining 2 cores to make 1 large toroid.
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Jack Bauer
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Re: How to build your own off grid inverter

Post by Jack Bauer »

Is that a version of the ozinverter? Thanks for posting :)
I'm going to need a hacksaw
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catphish
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Re: How to build your own off grid inverter

Post by catphish »

GaryHo wrote: Mon Sep 05, 2022 7:01 am If people are interested I can upload PCB files, Arduino code etc, I used 2 Aerosharp 3KW grid tie inverters for the toroidal transformer by unwinding and rewind 2 and combining 2 cores to make 1 large toroid.
I think I speak for everyone when I say we are interested. Please upload as much info as you can!
GaryHo
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Re: How to build your own off grid inverter

Post by GaryHo »

Jack Bauer wrote: Mon Sep 05, 2022 5:32 pm Is that a version of the ozinverter? Thanks for posting :)
Hi Damien, love your videos.

This is my design based on the work of Oztules who designed what is sold as the Ozinverter. I had originally used the Ozinverter design but had lots of issues and added Totem Pole Drivers to the Power PCB of my 8KW version. The 4KW is essentially an Ozinverter but has no Totem Pole Drivers and only 12 Mosfets rather than 24. The IR2110 driver ICs are fine with 3 MOSFETs on each leg but 6 is a bit much for them IMHO.

The control board I designed has an Arduino on it that controls the fans and will shut down the inverter if the battery voltage drops too low. This is essential if the voltage drops too low under load the inverter will have a catastrophic failure.

I will make a couple of small changes to the control board and put up the files shortly. I need change it to keep the Driver IC's turned off while the EG8010 IC boots up.
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Gary
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catphish
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Re: How to build your own off grid inverter

Post by catphish »

GaryHo wrote: Tue Sep 06, 2022 3:56 am This is my design based on the work of Oztules who designed what is sold as the Ozinverter. I had originally used the Ozinverter design but had lots of issues and added Totem Pole Drivers to the Power PCB of my 8KW version. The 4KW is essentially an Ozinverter but has no Totem Pole Drivers and only 12 Mosfets rather than 24. The IR2110 driver ICs are fine with 3 MOSFETs on each leg but 6 is a bit much for them IMHO.
Do you have schematics for this? EDA files? I'm trying to find good designs to learn from. Thanks!
GaryHo
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Re: How to build your own off grid inverter

Post by GaryHo »

I have files in PCB design files in Designspark and can make Gerber files. However, I know many don't like this but the PCB is my schematic.
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GaryHo
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Re: How to build your own off grid inverter

Post by GaryHo »

catphish wrote: Tue Sep 06, 2022 8:34 pm Do you have schematics for this? EDA files? I'm trying to find good designs to learn from. Thanks!
The attached PDF for the EG8010 will give you some good information to help understand. Section 6.6 is basically what my inverter is but has had modifications (Totem pole drivers in addition to the IR2110 IC's and an Arduino added to control fans and low voltage shutdown) but the circuit will give you a good grounding in the basic circuit.

The EG8010 is the IC that makes it all work, whatever you do don't bother with the EGS002 PCB's as the LM394 part of the circuit causes random MOSFET explosions.
Attachments
EG8010.pdf
(835.21 KiB) Downloaded 42 times
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