Electrical limiting factors for wind energy installations
[Examensarbete på avancerad nivå]
In this thesis the electrical limiting factors for installation of wind turbines stated by the Swedish connecting requirements, AMP, have been used to determine which types of power quality problems that will dominate when fix-speed wind turbines are installed. The main limiting factors are static voltage level influence and the flicker emissions. The investigation is based on field measurements on a stall-regulated and on a pitch-regulated wind turbine. It is found that the limiting factor from the power quality point of view is the flicker emissions if one turbine is installed. If three or more turbines are installed it is the static voltage variations that sets the limit, if the summation formula from AMP is used. It is found that the XR-ratio of the grid plays a very large influence on the installation possibility, and a ratio of 1.3-2.8 is the most favourable, depending on the short circuit ratio. The results shown in this thesis can be used to determine if there will be any problem with the static voltage level or the flicker emissions when stall-regulated wind turbines are connected to the network.