Research on Overload Capability of Oil-immersed Distribution Transformer Based on Hot Spot Temperature Model

As the user load continues to increase, the safety accidents caused by the overload of the transformer frequently occur. In order to improve the safety and stability of the transformer operation, this paper conducts an in-depth study on the overload capability of the transformer based on the hot spot temperature model. When the oil-immersed distribution transformer is overloaded, the internal temperature of the transformer rises, causing insulation aging and reducing the service life. This paper first introduces the characteristics of distribution transformers in different types of loads, and analyzes the changes occurring inside the transformers during overload operation, and then based on the hot water temperature calculation model in GB/T 1094. 7-2008 standard, from the perspective of operating temperature and heat aging, The research and analysis of the overload capacity of the distribution transformer is carried out, and the relationship between the allowable overload time of the transformer and the allowable overload multiple is obtained, and the theoretical analysis of the life loss is made.