i need urgent help designing an inverter using the parts i have

[edddyyyy]

m57959L driver modules x5
mg06100s-bn4mm igbt x2
a pic based spwm that seems to run ok giving op and inverted op

my 24v inverter just died, this inverter needs to run from 320-400vdc to give 220vac.
i have 2x 500w screw pumps at 500w rating each, drawing however 800w each.
the parts i have should be good for waaaaay more than that.

to save confusion, i have 2 sets of solar. one is 380dc and the other is 24v on mppt .
i will happily just go over to the 380vdc panels and leave 24v for domestic use.
i live off grid in east europe and cant buy parts. this is for my irrigation pumps. crops will start to die soon.

thanks

 

[audioguru]

You have no backup system? My grid is very reliable and is not used for anything that demands it but it has many backups.

 

[edddyyyy]

You have no backup system? My grid is very reliable and is not used for anything that demands it but it has many backups.

you are lucky then. my only other source is a big Diesel gen that i will need to lug up the hill. if it still works and has fuel.

backups are great if there is excess cash from the start but when on a shoestring budget its hard just to juggle finance for the basics.

so back to the thread; what do you think of the parts i have? will there be problems?

i think i will need to have the spwm signal with its overall pulse width to control output voltage with feedback but i could use a lash up tech just to get water flowing.

 

[audioguru]

Since my grid electricity is cheap and reliable then I have never needed and never used an inverter. I am not wealthy but I am not poor so if I ever need an inverter then I would just buy one, not make one.
For other people reading this thread who have designed and built inverters, you forgot to say the output current it must produce.

 

[edddyyyy]

the output current will be defined by the parts available that i have listed. there is no grid electricity where i am farming. i am using what i have to raise crops for food.
i am new to this forum but i have found similar responses from other forums. without wanting to be disrespectful, why answer my first ever post asking for specific help on an electronic project with comments about how good your grid is and how you just buy stuff instead of building, without having any interest in the info i provided.
is this just a way to chase newcomers away, or to get your post 'score' up, or did you just want someone to talk to?

please, is there anyone on this forum who DOES understand how to work with igbt bricks in inverter situations, understands the isolated power supply needs of the driver modules, inductance issues, gate capacitance issues, and any other stuff that would be useful or interesting?

 

[edddyyyy]

with the input voltage i will run and the ratings of the igbt the inverter should handle 38kw with an upper limit of 60kw.
maximum it will ever take is 10kw but for now 3kw is good overhead

 

[debe]

Interesting how some people don't seem to understand that not every one has a reliable Grid supply, or enough money to just go out & purchase what they need.

 

[JimB]

is this just a way to chase newcomers away, or to get your post 'score' up, or did you just want someone to talk to?

Welcome to ETO.
Please don't get all upset with AudioGuru, he is quite a knowledgeable bloke, but he does have this happy knack of going off on a bit of a rant now and then.

There are various members here who have good knowledge about inverters, but I am not one of them and so I cannot give much help.

JimB

 

[audioguru]

Interesting how some people don't seem to understand that not every one has a reliable Grid supply, or enough money to just go out & purchase what they need.

I am a city boy. I do not understand why some people live on the moon without electricity or money but have a good internet connection and maybe satellite TV.
Farms around here do not irrigate with pumps, they use rainfall. Why do some people try to grow crops in a desert?

 

[ronsimpson]

Why do some people try to grow crops in a desert?

Because we live in the desert. All the places with water have been taken.

 

[debe]

The OP did say he lives in Eastern Europe, perhaps conditions aren't as good as in Canada.

 

[cowboybob]

There are times when certain contributors to this forum embarrass the **** out of me.

Here's a new member facing a very serious problem (cannot irrigate his crops) and a member goes off on him like some elitist moron.

Farms around here do not irrigate with pumps, they use rainfall. Why do some people try to grow crops in a desert?

edddyyyy, please don't judge us all by the comments of this one jerk.

Makes me question the wisdom of my membership...

 

[schmitt trigger]

with the input voltage i will run and the ratings of the igbt the inverter should handle 38kw with an upper limit of 60kw.
maximum it will ever take is 10kw but for now 3kw is good overhead

edddyyyyy;
I just finished a 90 volt, 500 watt project and it took me three months to design, get the components, debug, build and fully test. Power electronics circuits are not trivial.

I say this, not because I want to discourage you, because I don't....... I actually feel this is an EXCELLENT AND WORTHWHILE PROJECT. And many people here would help you. But your crops will be dead by the time you finish up a fully tested inverter.

Could you rent some gasoline or diesel generators to power your pumps in the time it takes to complete the project?

 

[bountyhunter]

please, is there anyone on this forum who DOES understand how to work with igbt bricks in inverter situations, understands the isolated power supply needs of the driver modules, inductance issues, gate capacitance issues, and any other stuff that would be useful or interesting?

I know a lot of it. I know enough to agree with Audioguru since designing one requires a lot of broad range expertise like designing magnetics as well as power conversion. Probably the biggest challenge is designing in circuits that will keep it from blowing up under overloads or fault conditions. If you don't get that right, it ends up as a large boat anchor.

 

[bountyhunter]

Interesting how some people don't seem to understand that not every one has a reliable Grid supply, or enough money to just go out & purchase what they need.

which is a situation that requires even more "bulletproof" overload protection to keep from having your hardware destroyed.

 

[audioguru]

which is a situation that requires even more "bulletproof" overload protection to keep from having your hardware destroyed.

Also, the 500W water pumps are overloaded with 800W (said in post #1). If a pump stalls then the current will be extremely high. Isn't it stalled whenever it starts running?

 

[tcmtech]

Since my grid electricity is cheap and reliable then I have never needed and never used an inverter. I am not wealthy but I am not poor so if I ever need an inverter then I would just buy one, not make one.
For other people reading this thread who have designed and built inverters, you forgot to say the output current it must produce.

Don't bother pointing out reality to him AG. Been there done that. He will just toss a fit take his ball and leave.

https://forum.allaboutcircuits.com/threads/high-voltage-dc-220vac-solar-sine-inverter-help.121836/

He's got a mix and match of surplus and salvaged gear that apparently has very little rational logical cost Vs function Vs compatibility analysis behind it other than he wants to 'live cheap' off of RE sources (Because they are free energy sources you know.) rather than live the low-cost reality of us 'capitalistic trolls' that burn fuel and pay for utility power because in the long run it's cheaper and way easier to work with opposed to slowly starving to death saving the world.

please, is there anyone on this forum who DOES understand how to work with igbt bricks in inverter situations, understands the isolated power supply needs of the driver modules, inductance issues, gate capacitance issues, and any other stuff that would be useful or interesting?

Yes but you tossed a fit over my 'capitalistic views of life' and took your ball and left at the other forum.

Also, the 500W water pumps are overloaded with 800W (said in post #1). If a pump stalls then the current will be extremely high. Isn't it stalled whenever it starts running?

Damn the numbers of logic and reality AG! This guy needs solutions that don't cost money and he needs them last week!

 

[audioguru]

I checked. Farmers here farm on farmland, not on a desert. They make so much money selling their produce that they must pay a lot in income tax. Their tractors are deluxe with air conditioning and cup holders.

 

[tcmtech]

But buying land that is not worthless costs money and money is the 'capitalistic devil's blood'.

So anyway....

As for working with converting 400 VDC into a workable AC power the simplest basic inverter I can think of is to use an IGBT H-bridge driven by a pair of IR2110 high/low side driver ICs that are being controlled by a old fasioned inverter/converter driver chip like a LM3524 or such set up to provide a fixed duty cycle and frequency base to drive the IGBT H-bridge.

400 VDC with minimal PWM shaping will give a workable 277 VAC that can be stepped down and further cleaned up to make a sine wave that is acceptable to most any common AC induction motor using a common 277: 115/230 VAC isolation transformer followed by a simple LC filter between the transformer output and the motor.

If a basic voltage feedback circuit is added the 400 VDC could easily be fed into a 230/460:115/230 transformer as well which would allow for a fairly stable output voltage despite fairly wide input DC supply voltage swings.

 

[bountyhunter]

Also, the 500W water pumps are overloaded with 800W (said in post #1). If a pump stalls then the current will be extremely high. Isn't it stalled whenever it starts running?

I know whenever the motor in our AC started up it drew enough current to dim the house lights.