海上单桩风机桩基及整机振动测试和分析

Vibration Test and Analysis of Single Pile Foundation and Whole Machine of OffshoreWind Turbine Generators

盐城市某海上风电项目中所安装的100台4 MW风电机组,全部采用大直径无过渡段法兰单桩设计,为了解单桩基础及吊装完成的风机在海洋环境下的实际振动情况,对比风机吊装前后振动的差异,对4台单桩基础进行振动速度测试,通过对振动数据自功率谱平均分析,获取海洋环境中单桩基础的振动频率,另外对风场内吊装完成的1台风力发电机在相同位置处进行振动测试和分析,发现无论是桩基还是整机水平向振动强度都是竖直向振动强度的10倍至20倍,对比吊装前后测试数据可知风力发电塔在吊装后固有频率降低,风机桩基主要振动频率受环境耦合因素影响较大,但风机塔吊装完成后,振动响应主要集中在风机固有频率处。研究结果可为此类风机施工过程中桩基振动检验、海上风机的振动监测和故障诊断提供参考,也丰富了海洋环境中风机振动的研究资料。

An offshore wind power project in Yancheng City includes 1004 MW wind turbine generator units.Each of them is designed to build on the single pile foundation with large diameter and non-transition section flange caps.In order to understand the actual vibration situation of the single pile foundation and the hoisted wind turbine generator in the marine environment,the difference between the vibration of the single pile foundation before and after the wind turbine generators being installed was analyzed.The vibration speeds of four single pile foundations were tested.Through the analysis of the selfpower spectrum of the vibration data,the vibration frequency of the single pile foundation in the marine environment was obtained.Besides,one of the completed wind turbines in this wind field was tested and analyzed in the same position.It was found that the horizontal vibration intensity of both the pile foundations and the completed wind turbine were 10 to 20 times as large as that of the vertical vibration.The vibration natural frequency of the tower is reduced after hoisting,and the main vibration frequency of the wind turbine pile foundation is greatly affected by the environmental coupling factors.However,after the wind turbine tower is hoisted,the vibration is mainly concentrated in the natural frequency of the wind turbine.The research results can provide a reference for pile-based vibration testing,vibration monitoring and fault diagnosis of offshore wind turbines during the construction,and enrich the research data of wind turbine vibration in marine environment.