Just like the Campaign. You have to connect the command center to the research center via the hyper-loop. You can then use paths and repeaters (once you put down the hyper-loop power station). If you have unlimited power turned on, just have to connect up the command center
You can connect it to the Hydro Power Station through the Hyper Loop, or you can place down anything that radiates power next to it (Substation, Repeater, or Backup Generator).
Keep in mind that you need a lot of power to keep it going!