I am currently working on a project named 'A kVA sine wave inverter'.
Which topology is the best for 1 kVA 230 V sine wave inverter?Push-pull topology, half bridge or full bridge?
The block diagram is attached.

 

Go to a store and buy one. You will never build one for less than you can buy it.

That said push pull primary stage, H bridge secondary.

Or Sine Wave Modulated push pull primary and direct output secondary. That will give you something think about for a while.