Research On Condition Monitoring And Fault Diagnosis Of Wind Turbine Driving Chain Based On Vibration Method

Energy shortage and environment pollution are two emergency problems for us humankind to solve. Wind energy, as a renewable and clean energy, has enormous environmental benefits and commercial potential. In recent years, with the development of wind power technology, the electricity market share proportion of wind power and the unit capacity of the wind turbine are rising steadily. Once the wind turbines break down, there would be a tremendous impact on security and national economy. Vibration signal, as a carrier of fault features of the driving chain, can effectively reflect most of the fault information of the wind turbine drive train. In order to ensure safety and operation reliability of the wind turbine, wind turbine drive train condition monitoring and fault diagnosis are researched based on vibration analysis methods in this paper.To research the flexible operation characteristics of wind turbine drive train, this paper firstly compares the transient responses of six different drive train models (i.e.6-mass,4-mass, 3-massⅠ,3-massⅡ,2-mass and 1-mass) during electrical faults. And it is proved that the model structures and the flexible parameters have important impacts on the transient responses.Secondly, the typical fault and failure forms of bearings, shafts and gears in wind turbine drive train are analyzed, and then the fault characteristic parameters of the components are calculated and the vibration measuring points are determined.Thirdly, signal analysis methods including the time domain index calculation, fourier transform, zoom spectrum analysis, envelope spectrum analysis and wavelet analysis are researched and implemented with computer. A method based on wavelet multiresolution analysis for fault diagnosis of the wind turbine drive train is researched. The proposed method has the ability of fault feature library self-learning and multi-level early warning.And then an integrated on-line vibration monitoring and fault diagnosis system for wind turbine is designed, which is based on an embedded lower computer and a PC upper computer. The proposed system was used in large-scale megawatt-class wind turbine. It can determine the possible fault with the analysis of vibration signals.