Overvoltage Analysis of Offshore Wind Farm Transmission System

With the promotion of the “double carbon” policy, offshore wind power has become a crucial focus in renewable energy development. However, the expansion of grid-connected offshore wind farms has introduced overvoltage issues in longdistance AC cable transmission systems, compromising system stability and equipment insulation. This paper develops a detailed model of a wind farm, converter, and control system based on the characteristics of permanent magnet direct-drive wind turbines, simulating load shedding and short-circuit fault scenarios using PSCAD software. The results indicate that short-circuit faults can induce overvoltages exceeding 1.3 p.u., especially near the cable's starting and midpoint sections. Surge arresters effectively mitigate transient recovery overvoltages, while the sheath voltage remains well below insulation breakdown thresholds. This research provides theoretical support for insulation design and overvoltage suppression strategies in offshore wind power delivery system.