Allow me to answer your question with another question.

Why would you want to build such a device when you could just purchase one that is already available? Building a device of this power level is not a simple task. Moreover, many inverters produce outputs that are not sinusoidal which may damage other devices that are powered by it. Non-sinusoidal outputs may cause heat buildup issues with transformers that are connected to the power line. Transformers are used in the power supplies of many pieces of equipment.

I don't think you will find a kit for 20Kva, but you could start by searching the internet using "electronic kits inverter" as a starting point. There will be a large number of resources from which to choose. I would consider buying an Uninterruptable Power Supply (UPS) as an alternate approach. You will be drawing power from a large DC source. Will it always provide the same power level?

http://www.google.co.uk/search?sourceid=navclient&ie=UTF-8&rlz=1T4RNWN_enGB325GB320&q=20kVA+inverters

Don't discourage them, we need nominees for the Darwin Awards.

Realistically, this is good advice, you must be aware of your limitations, especially where safety is involved, and 20KVA certainly implies needing a lot of BBQ sauce.

Yes, sometimes it is difficult for me to suppress the dark side. I like Chris Tidas the comedian's take on it "No, no, don't stop him, we're about to learn a valuable lesson.."

Gotta love The Darwin Awards. It's just a shame it isn't easier to kill yourself. Ooops! There's that dark side coming out!

Oh I almost forgot - my favorite one was a guy asking how tight to torque the engine bolts on a jet airplane. What? Are you kidding me? This is a clear example of a disaster about to happen. I mean would anyone in their right mind take whatever information some unverified source might offer and put the lives of air passengers at risk based on an effectively random internet response? Please tell me who you work for so I can avoid flying on those planes! Really, if you don't have all the required information and training please stop and find the right help.

We should perhaps define a level past which it isn't ok to move ahead on guess work. How about anything over 500 watts or 300 volts electrical or maybe a horsepower mechanical. That way the injury would probably be survivable with only the loss of one eye or a couple of fingers.

I would suggest to "not go by", but stop and buy one!"

danke

every journey begins with the first step,,,,no matter the beaten already traveled path!

Taking a schematic and using some part hints make no inverter. Designing such devive takes you several weeks to months of engineering work and requires a lot of experience.

By the way - what is a "20kva-inverter" ? Your question is so fuzzy that you might get thousends of schematics and millions of component hints. You can only filter them by telling us which input, which output voltage, AC or DC, number of phases, required efficiency, safety regulations, protections etc.

Sorry, but do you really know what you are going to do ?

Regards

Are you sure you need this powerful inverter? I know for a fact that as far back as 1998 I saw a max 3.6kw inverter that could churn out this much for 20sec and 2kw continuous.

I don't know where you gonna get the juice to run such a high powered inverter from but, efficiency is also important. Using fan forced air to cool an inverter of this size is a waste of energy.

You should work out a lot of basic issues first and then start on the more complex ones and, last but not least, the safety side of things should also be considered, unless you wanna power an electric chair with it where safety isn't a paramount.

You are confusing 20KVA with 20KV. Your first video shows a boom truck that contacted a high voltage distribution line of probably 22KV. There were much more than 20KVA flowing through this mast.

The subject here is a 20KVA inverter giving approximately 50A at 240V. While still dangerous with a ~350VDC bus and a large capacitor bank, we are not on the same level of risk.

Nevertheless, unless one is to start a product development with a market, or one wants to study power electronics, it is better to buy a commercial inverter. If you have to build yours, look at Powerex's or Eupec's integrated modules that have all the gate drivers, capacitor banks already assembled. All you need is to add your DSP board and software.

Good luck

Development of an inverter, SAFELY, takes several months. I work for a crane manufacturing company and we manufacture our own inverters. This is not something to be taken lightly. Asking for help via the intermess is not the direction you should choose.

Please reconsider, and purchase one. The cost will far out weight the worst case scenario.