Why do central banks increase their rate to fight inflation? It was top news a week ago that Bank of Ukraine increased its rate to 30%.
And the news said they did this to fight inflation.

But I don't understand one thing: isn't the increased rate of "money printing" of the central bank only aggravates the problem? How is it supposed to reduce inflation?
From Monetary Policy:


  There are several monetary policy tools available to achieve these
  ends: increasing interest rates by fiat; reducing the monetary base;
  and increasing reserve requirements. All have the effect of
  contracting the money supply; and, if reversed, expand the money
  supply.


Increasing rates makes it more expensive to borrow and thus slows economic growth where the US in the early 1980s would be a good example to see the recession that was had at the hand of high interest rates at the time.