Easiest way I have found to train fighters is a "fighter station" specifically for that purpose.
I build a station, big hangers, big fuel tanks and a couple of engines. The engines are just enough to give it a high single digit or low teens movement rate. Put the station in orbit, assign it to a "Fighter Trainer" task force, and then load the fighters up on it.
Assign a commander to the station with good training, making sure he is the highest rank of any officer assigned to the station OR the fighters.
Then set the task force to train and voila! Your fighters get trained up without constant interrupts.
Since the station is so slow, it never gets far from earth, BUT it counts as a ship, so you get training. Once done, you can assign the trained fighters anywhere, including PDC fighter bases.