Inter-Turn Breakdown Fault Analysis and Winding Structure Optimisation of Winding of Dry-Type Transformers in Wind Farms

To address the problem of winding turn-to-turn breakdown faults in 35 kV dry-type transformers wind farms under overvoltage conditions, this paper establishes a simulation model based on structural dimensions and material parameters transformer windings. The distribution were calculated using finite element method. transient processes inside high-voltage coil by constructing multi-conductor transmission line (MTL) that took into account influence secondary winding. voltage was analysed for both lightning shock extra-fast conditions. results show maximum between turns is 5.282 kV; very fast 11.6 kV, which occurs first 2–3 layers section, close to insulation margin. On basis, structure optimised inter-turn after optimisation 9.104 reducing likelihood 24.1%. Finally, accuracy study verified testing transformer’s impulse before optimisation, providing reference stable operation farm practical applications.