In order to collect the operating parameters of the transformer more accurately, it is often necessary to arrange the sensor inside the transformer. There is a strong electromagnetic field distribution inside the transformer, so the electromagnetic compatibility problem of the sensor arranged inside the transformer is particularly prominent. In this paper, an equivalent circuit model of transformer windings is established, and the potential distribution of transformer windings under the impact of a standard lightning wave with an amplitude of 75kV is solved. Based on the potential distribution, the finite element method is used to solve the electric field distribution inside the transformer. The results show that the electric field inside the transformer reaches the maximum at 53 μs, and the electric field at the top of the iron core is much lower than the electric fields on the left and right sides of the iron core. Arrange the left and right sides of the iron core, then the sensor should be arranged as close to the two ends of the iron core as possible, where the electric field strength is about 0.3kV/cm.

Transformer,electric field distribution,lightning pulse,finite element method,sensor arrangement scheme