Sensitivity Factors in Site Calibration for Wind Turbine Power Performance Testing

• • Inflow angle as a sensitivity factor yields a higher calibration quality than wind shear: in the 190°–200° sector, R² improves from 0.8802 to 0.9544, and overall Type A uncertainty decreases, enabling an additional wind direction sector to meet the adjacent sector correlation change criterion (≤2%). • • Wind speed as a sensitivity factor (Method 2) achieves the highest calibration quality: R² increases from 0.9092 to 0.9551 in the 190°–200° sector, effectively removing the influence of wind shear and other factors on the wind speed ratio. • • Lower blade tip calibration fails to meet IEC 61400-12-3 requirements: self-consistency means range from 1.0176 to 1.0287 (outside 0.98–1.02), R² values are 0.6445–0.8078 (below 0.95), and adjacent sector correlation changes exceed 2% (e.g., 1.1495), due to greater terrain-induced flow distortion at lower heights. • • Discarding data bins with low correlation between sensitivity factors and wind speed ratio improves calibration quality: for wind shear, R² in the 190°–200° sector increases and Type A uncertainty decreases; for inflow angle, the improvement is more pronounced, with R² rising by 0.0742.