Non-Contact Measurement Dry Transformers Using an Acoustic Camera with a Modular System

The article describes the non-contact measurement of 1 MVA dry power transformers with epoxy resin insulation using an acoustic camera with a modular system. In this way, it is possible to analyze the frequency spectrum with the possibility of 3D monitoring of the transformer with the identification of the place with the greatest noise. The acoustic emission of two distribution dry transformers with the same type and power is compared, and then the condition of the structural parts of the "noisier" transformer is evaluated. Noise measurement in dB alone is sometimes not enough to detect a fault. It is necessary to perform an acoustic emission analysis through noise visualization and frequency analysis of the individual components of the transformer noise at idle and under load.