Early Faults Online Monitoring System Of Direct Drive Wind Turbine Slewing Bearings

Today,the global environmental pollution problems and energy shortage problem are becoming serious increasingly.As a kind of clean and renewable energy,wind energy has been more and more applied to the power generation industry.It is necessary for China which is a country with low per capita energy reserves and a single energy structure to develop the wind power generation.Wind turbines for wind power generation work long term in remote and harsh environment.The main shaft bearing of direct drive wind turbine is prone to break down.This not only affects the efficiency of power generation,but also increases the cost of power generation due to the high cost of maintenance faults.At present,the monitoring systems used in wind turbine are monopolized by foreign countries.Some of the domestic wind turbine monitoring systems are relatively simple.They cannot be aimed at the early fault of wind turbines and their function is not perfect.In view of this situation,this paper puts forward a slewing bearing early fault on-line monitoring system of direct drive wind turbines,and it can monitor and identify the surface fatigue crack and early fault of direct drive wind turbine slewing bearing.According to the characteristic of early fault signals,this paper selects the vibration monitoring method as the main method and selects the acoustic emission monitoring method as auxiliary method.Then the overall design scheme of the monitoring system is determined.In the aspect of hardware design,according to the relevant national standards and the characteristics of monitoring signals,this paper selects the appropriate hardware devices,such as sensors,amplifiers and data acquisition cards.In the aspect of software system design,LabVIEW is used to develop the monitoring system for the wind turbines.The functions of the system include user login and management,data acquisition and online monitoring,data analysis and data storage and so on.Finally,the system is tested and verified.Do the experiment in the wind turbine laboratory of the Gold Wind in Yancheng.Use the software to collect the vibration signal and compare with the vibration signal with the faulty wind turbines.Use the software of this paper to analyze the results.Do the acoustic emission signal comparison experiment with small bearings in laboratory.Analyze the results with EMD signal decomposition and reconstruction method.Using the above two experiments,the validity of the monitoring system is verified.