This is the simple explanation (simple and short theory) about DC to AC inverter by Electronic Department, Nothern Alberta Institute of Technology. You will find the information about inverter diagram design, inverter transformer design, transistor selection for inverter and more inverter theory which may be you need for your inverter design reference.

How to Make an Inverter Circuit..? You might download the basic theory of inverter first, download the document from the following link:

I am interested in learning about designing of inverter 12vdc to 220vac up to 3000watts.

bravo

I am interested in learning about designing of inverter 12vdc to 220vac up to 3000watts.

I will love to understand how to built 12v inverter.