Thermal behaviour analysis of a high voltage inverted-type current transformer

A high voltage current transformer of the inverted type is a commonly used measurement equipment in power grids. The thermal behaviour of the current transformer has a significant impact on its operating conditions and is directly related to its service life. The study presents a three-dimensional simulation model of a 220 kV inverted-type oil-immersed current transformer, and the fluid and temperature field are analysed by the finite volume method. The simulation results show that the hot-spot temperature under the rated load of the calculation model introduced in the study is 61.5 degrees C, and located at the upper part of the core and the secondary winding. An experiment setup was designed to measure the temperature distribution inside a LVB-220W3-type current transformer. The temperature data measured under the rated load indicate that the simulation results agree well with the experimental results.