A Proposed Power Transformers Failure Assessment Method for Resolving Harmonic Distortion Problem

Power utilities try to protect the power transformers as they are the most expensive assets in the power system. These equipment are highly exposed to the harsh harmonic distortion environment. Power transformers' operation is negatively affected by harmonic distortion as they encounter overheating, increases in power losses, deterioration of their life expectancy, etc. Traditionally, transformer failure investigations exclude the harmonic distortion, this can no longer be ignored. There is an international standard that gives harmonic limits for power transformers. This paper presents a proposed method to be used during transformer failure investigation and transformer harmonic monitoring management. This gives power utility awareness of the number of transformers that are part of the network with the highest total harmonic distortion (THD) and to partake in harmonic mitigation to reduce the exposure. The power transformers will operate based on the expected number of years as per design. The harmonic measurement data assists the transformer's failure investigation by identifying the period the transformer has been exposed to the harmonic distortion.