Have you checked the wiring for faulty connections and ratings? (ex. 12gauge+ wires for 20A) The most obvious signs are thin-looking wires in the circuit or bunch of "rat-tail" connections; if there's a problem, the wire or the connections will heat up and will "pop" your fuse.
If you're not qualified to do so, call for a professional electrician to do the job.

There's no other reasons for this other than faulty wiring since it's happening too often to be caused by a bad fuse, otherwise, frequent power outage.