Your ultimate protection from Power Interruptions
 
Aircraft power, especially when the aircraft lands and pulls into the gate, can go thru intermittent phases as it switches electrical power from the engines to the gate's electrical cables, or an auxiliary power unit withing the aircraft.  

And of course, as it leaves and switched back to engine electrical power, again there could be a short power interruption.  

AVDS nodes can be protected from these very short phases in power interruption by adding power hold up units next to each Node to provide continuous power over these short interruptions.