How to perform over night computations while having display powered off?

Hi,

I'm running over night renderings with my Dell precision Mobile 5540 laptop running win 10 pro (Version 10.0.18363 Build 18363).

I have an issue preventing me from running long computations with the laptop. The problem is that every time the screen goes off also the computer goes into sleep mode and, consequently, the computations won't be performed. 

When I set in power options "turn off display" to "Never", I'm able to perform computations but the screen is on all the time which doesn't make any sense. 

Is there a way to prevent Dell laptop from going into sleep mode when the screen is powered off by windows? Alternatively, is there a way to manually power off the display?