Half-bridge DC/DC converter

I am trying to simulate a half-bridge DC/DC converter, and I would like to increase the output voltage to at least 320 V.
Do you have some suggestion on how to do that?

Yup increase the inductance of Ls to effectively increase the turns ratio, ie step up.
Also you ought to configure the pulse directive to produce a inverse square wave across the fets.
The final design would need to cater for magnetic flux in the trans, ie ,make sure it doesnt saturate.