Is it possible to chance config settings in controller?

Read the so nicely written and easy to follow documentation. It even has a search option to make locating subjects even easier.

setting-a-config-item

It's not what it is about.
I have to be permament change in config, not temporary

That is not what you are asking!

If it must change permanently, why not just change it in the config file?
To change it in the controller one could assume you want to change it temporarily