Monitoring technologies for large power transformers

Key assets in any petrochemical facility that purchases primary power are the incoming transformers. Typically these range from 20 - 60 MVA. Facilities have been implementing monitoring technologies for other key assets such as motors, generators, cables and switchgear, but monitoring of the all-important transformer has been minimal. Technology exists today that can monitor and control all operating characteristics of power transformers including the cooling system, load tap changer, dissolved gas content, bushing health, partial discharge levels, oil levels, pressures, temperature and status of other alarm contacts. Monitoring technology has evolved to a state that outages for periodic testing and maintenance can be minimized. This paper will review the practical side of monitoring power transformers and will discuss the analytics used to determine the health of these assets.