What could cause circuit breakers to trip when power is restored after an outage?
In general, this is a sign of a circuit loaded a bit too heavily. After an outage, everything is starting at once - motor loads, in particular, tend to draw a very large current at startup - if a circuit has several motor loads which do not usually start at the same time, it may not trip in normal service, but if all the motor loads start at the same time, it may trip.

As a general rule, my habit at this point is to shut off nearly everything during an outage, with the specific intent of reducing the local draw on power restoration and to isolate as many things as is reasonably possible from the initial restored power, which can be a bit unstable due to everyone else's loads all trying to start at once. Once power has been restored for a few minutes I turn things back on. It's more fuss than most people go to, but it works for me.

If you have particular circuits which are prone to trip on power restoration, you might both turn those breakers off during an outage and turn off at least some of the items on them before manually turning the breaker back on after the outage. 

However, a better option for the long term would be to rewire things so that the circuits in question are not overloaded upon restoration of power.