Duty based maintenance for on-load transformer tap changers

This paper provides an insight into work involving new maintenance strategies to be used by a power distribution utility for on-load tap changers. Alternative strategies are examined and the advantages of condition based maintenance are outlined. A maintenance decision making algorithm is developed which considers the principal causes of tap changer failures and can advise maintenance personnel when a unit requires visiting. The benefits that this system has provided to the utility are an increase in the average period between maintenance visits and a reduction in possible disturbances to consumers as well as utility costs.