Calculation of Electric Field Under Lightning Impulse in a Natural Ester Retrofilled 110 kV Transformer

Natural ester retrofilling is recognized as a key technology to realize a new energy system globally. This paper takes a 110 kV power transformer as the research object, uses the finite element method to calculate the capacitance and inductance parameters of the equivalent circuit model, establishes the equivalent circuit model based on the parameters, calculates the voltage distribution of the windings and the electric field distribution of the transformer under lightning impulse, and analyses the influences on natural ester retrofilling on the electric field distribution of the transformer as well as the insulation margin.