中文摘要：

针对水轮发电机组竖向水力振动荷载的复杂性及其通过轴承机架等传递至下机架基础等部位的不明确性,提出了基于正交多项式分解的水力机组动荷载时域识别方法,该方法具有所需测点信息少,识别速度快,避免多次重复正分析试算等优点。同时针对该方法中由模态荷载通过杜哈梅积分得到模态位移的过程中,杜哈梅积分具有时间累积误差的问题,提出了利用正交多项式的正交性质及位移与速度、加速度的导数关系,建立各阶模态位移和模态荷载的关系式,避免了杜哈梅积分计算,提高了计算效率和精度。算例表明,该方法可以有效、方便地识别任意形式时变动荷载。

英文摘要：

Hydro-turbine vertical dynamic load is very complex. The transmission of dynamic load has un-certainty through the bearing-housing-frame-pier. A dynamic load identification method of hydraulic turbinewas proposed based on orthogonal polynomial approximation. The algorithm not only has high speed but al-so needs less measuring points information. Comparing with the genetic algorithm identification,the orthogo-nal polynomial algorithm could avoid falling into local convergence and don＇t need repeat many times posi-tive analysis. The traditional orthogonal polynomial identification obtained the modal displacement throughthe modal force by Duhamel integral. But the time cumulative error problem of the Duhamel integral de-creases the identification accuracy of the dynamic load. The algorithm proposed in this paper constructs therelationship between the modal displacement and modal force according to orthogonal characteristic of thepolynomial and derivative relation between the displacement and velocity or acceleration. The proposed meth-od does not need Duhamel integral and increases the identification accuracy. Numerical simulations demon-strate that the identification and assessment of dynamic loads are effective and consistent when the pro-posed method is used.