Inverter more than 20KW on grid system super market store load.

Yaskawa, Schneider, and SMA all have 500kW inverters. I think all of them are 3-phase and higher voltage then typical 208V 3-phase you see in the US.
And they probably all have ones in between 20kW and 500kW.
I think you need to backup a bit and start with what you're trying to do.
Is your goal to offset a residence's or a business's consumption via net metering? If so, how many kwH? And have you estimated how many kW of panels you need by playing around with http://pvwatts.nrel.gov/pvwatts.php ?
Or is your goal to setup a solar farm that you sell power to one or more utilities? (If that's your goal you're probably out of your depth - that you're asking whether there are >20KW inverters likely means you don't know anything about interconnecting with the utilities and such, so you would have a lot to learn)
Or is your goal something else?

You can buy them as large as 1 Mw. Once you go above consumer grade, you are into Commercial and Industrial systems. Those systems require licensed professionals to design and operate. It also means custom made for the application.