在大型风电机组的机械载荷测试中，叶片自重引起的摆振弯矩和挥舞弯矩的载荷标定精确度直接影响叶片和风轮的载荷测试效果。因此分析叶片自重在应变片测量位置的弯矩解析结果是叶片载荷标定的关键。首先，运用解析几何原理，提出了一种基于优选的三维坐标系和坐标变换的叶片自重弯矩解析方法。其次，为了消除主轴倾角对优选的三维坐标系的影响，提出了一种在优选的三维坐标系中调整叶片重力矢量方向的方法，并推导出了考虑各种影响因素下的弦摆振弯矩、弦挥舞弯矩的解析表达式。最后，在实际的叶片载荷测试项目中，应用两种标定分析方法进行对比，两种方法得到的叶片载荷测试结果具有很好的一致性和代表性。理论分析和试验结果验证了本文所提的叶片自重弯矩解析方法对叶片载荷标定的有效性和可行性。

In mechanical load measurement for large wind turbines, the accuracy of load calibration for edgewise and flatwise bending moments implemented by blade gravity has a direct influence on the testing effectiveness for blade and rotor loads. Therefore, analyzing the bending moment analytic results of the blade gravity at the strain gauge measurement position is the key to blade load calibration. Firstly, using the principle of analytical geometry, an bending moment analytic method for blade gravity is proposed based on optimized three-dimensional coordinate system and coordinate transformation. Secondly, in order to eliminate the influence of the main shaft tilt angle on the optimized three-dimensional coordinate system, a method to adjust the direction of the blade gravity vector in the optimized coordinate system is proposed, and the analytical expressions of blade edgewise moment and flatwise moment are obtained taking into account various influential factors. Finally, in the actual blade load test project, the two calibration analysis methods are applied respectively, and the blade load test results obtained by the two methods have good consistency and representativity. The validity and feasibility of the proposed analytic method for gravity load calibration of blade bending moments are verified by theoretical analysis and testing results.