The former Addicks defender was chosen as Phil Parkinson's replacement on Friday and after watching a 2-2 draw at Sheffield Wednesday from the stands, began his duties on Monday morning.
Speaking to Sky Sports News, Powell said: "I never applied for the job but it was a fantastic feeling when I was asked.
"I hope I can give the club the stability they've been lacking for a while.
"I look to get the supporters' backing and find my style as a manager.
"Keith Peacock (caretaker manager) is very important to the club but I'll be bringing in some of my own coaching staff also."