section_path: Wind farms/Generator characteristics and stability
section_name: Generator characteristics and stability
paragraph_text: Generator characteristics and stability
  
  Most modern turbines use variable speed generators combined with either a partial or full-scale power converter between the turbine generator and the collector system, which generally have more desirable properties for grid interconnection and have low voltage ride through -capabilities. Modern turbines use either doubly fed electric machines with partial-scale converters or squirrel-cage induction generators or synchronous generators (both permanently and electrically excited) with full-scale converters. Black start is possible and is being further developed for places (such as Iowa) which generate most of their electricity from wind.
  
  Transmission system operators will supply a wind farm developer with a grid code to specify the requirements for interconnection to the transmission grid. This will include the power factor, the constancy of frequency, and the dynamic behaviour of the wind farm turbines during a system fault.