Simulation of switching overvoltage of step-up transformers in wind farms

The transformers are often suffered the insulation breakdown accident caused by overvoltage in some wind farms and the problem has become particularly prominent. The switching overvoltage is considered to be an important cause to insulation accident. This paper will establish a wind farm model, and research on the relationship between the switching overvoltage and the length of feeder cable and the number of feeders that have been running. Firstly, this paper establishes two dynamics simulation system to analyze overvoltage of step-up transformers on feeder in PSCAD. Finally, making simulation and analyzing the overvoltage of step-up transformers on feeder. The simulation results show that the feeder length and the number of running feeders will have influence on the amplitude and steepness of switching overvoltage, which can provide some references for the insulation design of cable system and the step-up transformer in offshore wind farms.