Can predictive maintenance support early fault detection in power system protection

I suppose it depends on what you mean by "early". Most faults either appears very quickly (e.g. nail through a cable, or loose wire making contact with something it shouldn't) or are very gradual (e.g. due to damp ingress or corrosion or insulation ageing).

I suppose that at one end of the scale, loop impedance and insulation resistance tests during periodic inspections should give early warning of long term deterioration.

In more critical systems (e.g. where IT-earthed systems are employed) insulation monitors provide continuous checking.

For the more up-market there are "smart" circuit breaker systems that can monitor load & residual currents in real time too (I've never used them, but they seem to exist - e.g. https://www.se.com/ww/en/work/products/product-launch/smart-panels/overview/) which might help with deterioration caused by small overloads of long duration for example.

I'm intrigued by your mention of "vibration-based condition monitoring" - please do share more! (I'm imagining listening to things like big transformers but am probably way off the mark).

   - Andy.

I'm not too sure what the OP has in mind, but there certainly are systems for listening to transformers for buzzes and sizzles and motor bearings for whines and screeches, especially in the ultrasonic or infrasonic where a human would not notice. This sort of monitoring is already very much a thing that occurs on critical systems. There are electrical systems as well, such as partial breakdown monitoring of cables, where any high frequency bursts of current that are not the same at both ends of the cable are logged as possible insulation weaknesses opening up and then closing and trapping charge. This is more use in HVDC systems, where things tend to be stressed much closer to failure - with multiple sensors and some time of flight sums, the approximate position can also be deduced.
As you allude, no good against instant catastrophic events like falling trees or digger buckets in the wrong place of course, but like the more traditional temperature stickers and periodic monitoring for water or carbon char in oil samples, these things do have their place.
Mike

I'm not too sure what the OP has in mind, but there certainly are systems for listening to transformers for buzzes and sizzles and motor bearings for whines and screeches, especially in the ultrasonic or infrasonic where a human would not notice. This sort of monitoring is already very much a thing that occurs on critical systems. There are electrical systems as well, such as partial breakdown monitoring of cables, where any high frequency bursts of current that are not the same at both ends of the cable are logged as possible insulation weaknesses opening up and then closing and trapping charge. This is more use in HVDC systems, where things tend to be stressed much closer to failure - with multiple sensors and some time of flight sums, the approximate position can also be deduced.
As you allude, no good against instant catastrophic events like falling trees or digger buckets in the wrong place of course, but like the more traditional temperature stickers and periodic monitoring for water or carbon char in oil samples, these things do have their place.
Mike