So you have 3 phase or single phase?
If you have 3 phase, is it happening on each phase.
If the problem has started in the last month (stronger, variable direction winds) could be bamboo ot trees breifly touching the power lines.
PEA will get round to it.
If the problem has been going for awhile, get someone to check the tightness of your meter box connection, especially the neutral.
Starters