Research on distributed temperature monitoring technology of transformer based on variational mode decomposition

Transformer temperature monitoring is important to power system operation and maintenance. However, there is currently a lack of in-situ monitoring methods for the internal temperature of power transformers. This paper proposes a new type of transformer temperature in-situ monitoring scheme. With the help of the characteristics of the sensing optical fiber, which is not subject to electromagnetic interference, small adhesion, and non-metallic materials, the distributed Raman temperature measurement technology is used to realize the in-situ accurate measurement of the temperature of the three-phase winding and the oil tank area of the transformer. A 10 kV oil-immersed transformer prototype was successfully developed, and the internal temperature variation law of the transformer was obtained by a short-circuit temperature rise test. At the same time, a Raman temperature denoising algorithm based on variational mode decomposition and Pearson correlation coefficient is proposed, which realizes the accurate measurement of the internal temperature of the transformer and provides a new scheme for online monitoring of transformer temperature.