Assessment on energization sequence for reducing sympathetic interaction between wind trubine transfromers

Increasing installations of large offshore wind farms are being designed and commissioned. The collection grids of these wind farms usually accommodate hundreds of wind turbine transformers. Energization of these transformers is likely to cause sympathetic inrush due to the close electrical distances between them. The wind turbine transformers are consequently subjected to long duration mechanical and thermal stresses under various energization conditions. In this paper, a network model of wind farm collection grid, developed and validated against field measurement results, is utilized to assess various energization sequences for reducing the sympathetic inrush. Deterministic assessment under a critical energization condition and stochastic assessment under stochastic energization condition were conducted. Both indicate that the optimum sequence is to energize wind turbine transformer from the one closest to the offshore platform to the one farthest from the platform.