Located on the back half of the construction site is a single power ring (so far) that the coaster track passes through. These power rings are located throughout the ride, and this particular one is located in the first half of the interior portion of the ride. As you can see, the power ring has been mounted to the frame of the supporting steel structure. This is just the first of many to be installed in the coming weeks and months.
Source: https://blogmickey.com/2019/08/show-scene-installation-begins-for-tron-lightcycle-run-at-magic-kingdom/