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Knowledge of lightning impulse (LI) voltage distribution over transformer windings during the design stage of the transformer is very important. Specific design differences in inductive voltage transformers make the transient analysis approach different to the approach to the power transformers. In this paper, a methodology for acquiring lightning impulse voltage distribution over high-voltage (HV) winding of inductive voltage transformers is presented and evaluated. Resistance, inductance, and capacitance matrices are calculated using the integral and boundary element methods (BEM) approach. Additionally, in order to improve the capacitance matrix solver, adaptive cross approximation (ACA) is applied. These parameters are then used to solve the equivalent circuit model in time domain. In order to evaluate the methodology, an experimental and numerical investigation of the layer discretisation, iron core influence, and accuracy of the proposed methodology is performed. The comparison of numerical results with measurements confirms the validity of the methodology.

In this paper, a solver based on a 3D boundary element method (BEM) is presented and verified on a transformer geometry. Using a triangular surface mesh of a winding, the unknown charge distribution is found from known potentials of surfaces using the integral equation approach and point matching. The capacitance matrix is calculated from known potentials in nodes of the system. The application of BEM and point‐matching results in a fully populated system matrix. Therefore, a matrix reduction technique adaptive cross approximation (ACA) is employed in order to reduce the CPU time and memory requirements. Both the accuracy of the direct and the accuracy of the ACA approach are benchmarked against the results obtained using the professional finite element method (FEM)‐based software.

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