A case study of condition monitoring for mold transformers on urban railway transit

도시철도용 몰드변압기 상태감시를 위한 사례조사 연구

Since urban railway transit is one of the most essential transportation systems, its power facilities must ensure high reliability and safety. Currently, urban railway operating organizations perform TBM (Time Based Maintenance) on power facilities. However, in order to improve management efficiency and system safety, CBM (Condition Based Maintenance) is preferred. Among various power facilities, mold transformers has been chosen as the object of study since it is widely used for the purpose of minimizing volume and weight, and due to safety against fire. In this paper, various transformer failure cases due to electric, thermal, mechanical and environmental factors have been collected and analyzed. In addition, investigation on national and international condition based maintenance cases and the characteristics of sensors widely used for transformer monitoring has been performed to suggest the optimal condition based maintenance technique for urban railway systems.