Generators are two massive and unique ANMCs; they do not attack Aya Brea, but are a story-related threat because they are powering a barrier that is keeping Aya from entering the lowest recesses of the Shelter known as Neo Ark. They are known as dynamos in the introduction of Neo Ark meaning that they are capable of generating power indefinitely.
Both fights are virtually identical; the life support system that helps regulate their vital functions must be destroyed before the player can kill the generator. They are both protected by a series of Watchers, but if the player disables them while in the Pod service gantry, there will be nothing protecting them.
This is the first Generator encountered. It can be found on the first floor of the Power plant and is met fairly early during the exploration of Neo Ark. The door to the building is locked and requires solving a puzzle in the Shrine, first.
The second of two Generators encountered, the Beta Generator is identical to the Proto Generator except having more health. It can be found on the second floor of the Power plant. A more complex puzzle at the Altar must be solved before the door to other side of the building can be unlocked.