Study On Acoustic Emission Characteistics And On-line Monitoring Application Of Rotating Support For Wind Turbine

As the steering and load-bearing components of blades and engine room,slewing support is widely used in large components of wind turbine sets.However,there is still a lack of reliable methods for real-time on-line damage monitoring.Therefore,acoustic emission monitoring technology is proposed to dynamically monitor the crack growth process of 42CrMo4 steel,the main material of rotor bearing.First,according to the experimental equipment supporting die design steel specimen;Then the specimen was stretched and bent at three points by the electronic universal testing machine,and the acoustic emission signal was collected by the acoustic emission instrument during the preset crack change process.Finally,the characteristic parameters of acoustic emission monitoring signal are extracted,and the time domain graph analysis method is used to study the law of amplitude,energy,count,duration and other characteristic parameters changing with time.The experimental results show that the acoustic emission characteristic parameters of the specimen show different characteristics at different stages of initiation,extension and fracture,and the damage condition of 42CrMo4 steel can be characterized and evaluated by these characteristic parameters.In the actual operation process,the slewing support of wind turbine generator is in the alternation of wind load,generator load,variable pitch and yaw,and the acoustic emission signal is affected by the interference of high frequency multiplication of vibration.Transformed into equivalent fatigue in this paper,the complex conditions of time,from the amplitude,energy,count and the duration of the characteristic parameters such as the law of change over time,and the amplitude,energy,count and the duration of the characteristic parameters such as the law of the change over time for fitting,to carry out the acoustic emission in wind turbine slewing bearing failure diagnosis the application and research.Finally,through the correlation analysis of the incoming flow’s wind speed,rotating speed and acoustic emission characteristic value,it is confirmed whether the working condition of the unit interferes with the acoustic emission monitoring.