UNE-EN IEC 61400-12-1:2024

64 This part of IEC 61400 specifies a procedure for measuring the power performance65 characteristics of a single wind turbine and applies to the testing of wind turbines of all types66 and sizes connected to the electrical power network. In addition, this standard describes a67 procedure to be used to determine the power performance characteristics of small wind turbines68 (as defined in IEC 61400-2) when connected to either the electric power network or a battery69 bank. The procedure can be used for performance evaluation of specific wind turbines at70 specific locations, but equally the methodology can be used to make generic comparisons71 between different wind turbine models or different wind turbine settings when site-specific72 conditions and data filtering influences are taken into account.73 The wind turbine power performance characteristics are determined by the measured power74 curve and the estimated annual energy production (AEP). The measured power curve, defined75 as the relationship between the wind speed and the wind turbine power output, is determined76 by collecting simultaneous measurements of meteorological variables (including wind speed),77 as well as wind turbine signals (including power output) at the test site for a period that is long78 enough to establish a statistically significant database over a range of wind speeds and under79 varying wind and atmospheric conditions. The AEP is calculated by applying the measured80 power curve to reference wind speed frequency distributions, assuming 100 % availability.81 The standard describes a measurement methodology that requires the measured power curve82 and derived energy production figures to be supplemented by an assessment of uncertainty83 sources and their combined effects. Uncertainty sources of wind measurements shall be84 achieved from procedures described in the relevant wind measurement equipment standards85 while uncertainty of the power curve and annual energy production shall be achieved by86 procedures in this standard.