I found two sets of power armor in a large crater surrounded by centaurs and discovered that once again I cannot wear it without receiving training. I assume that you must once more be trained by the brotherhood of steel and I was wondering if anyone has found their location yet because I cannot seem to find them. I would like to wait and find it on my own but I want to use power armor pretty badly so any info would be appreciated.

Just advance the main quest, you might have the option to meet them if you take a certain path. Or pick up a certain follower.