There are many different versions of the Three Emperors of the Three Emperors and Five Emperors.
One is: Fuxi, Huangdi, Shennong; the other is: Emperor of Heaven, Emperor of Earth, Emperor of Tai. Of course there are.
Personally, I think the Three Emperors refer to: the Emperor of Heaven and the Jade Emperor, who control the laws of heaven and the gods; the Emperor of the Earth, Yama, who controls the laws of the earth and the ghosts; the Emperor of Humans, who controls the laws of the country and the people. They each perform their duties.