METHOD FOR DETECTING A POWER LOSS WHEN OPERATING A WIND POWER INSTALLATION OR A WIND FARM

Provided is a method for detecting a power loss when operating a wind power system including a wind power installation and which feeds electrical power into a grid. The electrical power is fed into the grid with an active and reactive power component at a current operating point. The method includes detecting an overall power loss caused by feeding in the electrical power at the current operating point, and estimating a reactive power loss caused by feeding in the reactive power component at the current operating point. The reactive power loss is determined from a difference between the overall power loss and an active power loss assigned to the current operating point. The active power loss corresponds to a power loss of a comparison operating point where the same amount of active power is fed in as at the current operating point, but no reactive power is fed in.