Influence of Oil Duct Variation on Thermal Characteristics of Converter Transformer Winding

Abstract

Power transformers are the key equipment of power transmission and distribution system. Therefore, it is necessary to study the influence of different fault types on the temperature distribution of transformer windings. Based on the real converter winding model, a fast solution method is proposed to obtain the temperature and velocity distribution of the winding. And the typical winding faults are analyzed. Oil duct flow velocity in the maximum oil baffle plate, the flow of the oil take away heat, makes the temperature rise between regions is about 6–8 K. Hot spot temperature of the winding is located at 184 the layers (92% of the height) and is 67.3 °C. With the decrease of oil flow velocity, the increase of the overall winding temperature and the overheating of the end area as a whole. Oil change for little effects on the overall temperature of the winding, but the wire under the narrowed oil channel generated local overheating and became a new hot spot. This paper provides a preliminary exploration for the development of transformer thermal faults.