Verification of Maintenance Intervals for Vacuum On-load Tap-changers

摘要

The long maintenance intervals of vacuum tap-changers require extensive testing. Since resistive vacuum tap-changers where introduced to the market in the 2000s there are very few of these that have been in service 10-15 years without any kind of maintenance and likely no experience at all from installations with longer service intervals. To really verify that a tap-changer can handle 30-40 years in difference load conditions and applications, testing beyond normal type testing is needed.