A Smart Supervisory System for Distribution Transformers

Traditionally the determination of the health and life of a distribution transformer (DT), has relied on modelled rather than measured data. This can lead to inaccurate assessment of transformer health and non-optimised transformer utilisation. This paper presents a smart supervisory system for DTs incorporating self-protection, communications and comprehensive monitoring features. The monitoring includes fibre-optic winding hot-spot temperature (θHS), sensing, top oil temperature (TOT), sensing and dissolved gas analysis (DGA), through monitoring hydrogen levels. Self-protection is implemented through the direct control of the medium voltage (MV), switchgear, according to sensed θHS. Communication allows for transformer health data to be sent to a remote monitoring centre. This system provides accurate and dynamic monitoring of DTs, improving reliability and utilisation levels, and simplifying asset management.