Advanced Materials Research Vols. 953-954

Abstract: The spatial and temporal variations of wind field and the atmospheric turbulence characteristics are important factors that affect the migration and dispersion of local atmospheric pollutants. Since the numerical meteorological forecasting system with high resolution is the foundation of atmospheric dispersion simulation, more and more attention has been drawn to the application of numerical weather prediction systems in wind field prediction and atmospheric simulation. This paper reviewed the widespread application of numerical weather prediction systems in wind field prediction and atmospheric simulation with the focus on the mesoscale weather forecasting system with high resolution, for instance WRF and MM5, as well as the requirement for numerical weather prediction in the simulation research of wind field prediction and atmospheric dispersion.

Abstract: The research has identified turbulence intensity, annual wind speed and air density as the three basics of fatigue loads, in this paper, we call it three basics for short. This paper presents a method to analyze the three basics of the wind turbine fatigue loads. It explains the fatigue loads analysis idea and method of the three basics and it use the analysis method to research the extent of the influence by using a 1650kW wind turbine as an example. It can be seen from the results that the wind resources increase one classification, the influence of the turbulence intensity is the greatest, then the annual wind speed, finally the air density.

Abstract: Aiming at the small magnetic wind turbine, finite element software ANSYS is used to establish the model of rotor system with passive magnetic bearing, and obtain the vibration mode and critical speed of rotor system in situations: free-free, rigid bearing, hybrid combination of elastic and rigid bearing. Experimental analysis of critical speed of the rotor system can be conducted with the testing platform built by the B&K Vibration Measuring System.The result shows that the simulation analysis are approximately agreed with the experiment result. The simulation analysis has instructive significance in the structure optimization of magnetic bearing and rotor system and provides basis for vibration characteristic analysis of permanent maglev wind turbine generator and dynamic characteristics of structure.

Abstract: Abstract. For a mountain wind farm in southern China, the paper used CFD software, METEODYN WT, to simulate the wind in all directions to assess their speed-up factor, turbulence intensity, inflow angle and horizontal deviation caused by the terrain. The turbulence intensity, the horizontal deviation and the inflow angle in the met-mast position should be low or small, and the speed-up factor should be able to represent the average level of all the wind turbine sites. The positional relationship of the wind turbine and met-mast is reference to IEC61400-12-1. The paper provided two optional areas.

Abstract: In order to show the performance of the outer rotor permanent magnet generator timely and accurately under different input parameters, we coupled two software of outer rotor permanent magnet generator experimental platform based on LabVIEW (Laboratory Virtual Instrumentation Engineering Workbench)-Virtual torque and Three-phase electric parameter tester. Firstly, we picked up the DLL (Dynamic Link Library) of virtual torque and generated an excel file through VB (Visual Basic), through LabVIEW we picked up the excel form to acquire the system input parameters (torque and speed); Secondly, we collected the real-time parameters (voltage and current) of three-phase power meter by means of the LabVIEW serial communication; Lastly, we could see the efficiency of the outer rotor permanent magnet generator on the LabVIEW front panel. The experiment show that we can couple the input and output parameters of the system based on LabVIEW, and we can see the efficiency of the outer rotor permanent magnet generator under each fixed input parameters. This experiment avoid the tedious work that people deal with data, optimize the software system of outer rotor permanent magnet generator experimental platform, and provide the technical support for optimal design of permanent magnet generator.

Abstract: In order to determine the best maintenance time of wind turbines and identify the fault type when it is the best time to do the diagnosis work immediately. The establishment of 4-level safety status model for critical parts of wind turbines, based on wind turbine parts’ significance level, was proposed. According to the corresponding safety level of the wind turbines in real-time working status, you can decide whether the wind turbine needs diagnosis at the time or not. Therefore, we should take measures to monitor the real-time working conditions of the wind turbine’s critical parts, confirming whether the critical part need the fault diagnosis analysis or not according to its real-time working safety status. If it is the right time, then the corresponding fault diagnosis process will be initiated, through which the real online fault diagnosis can be achieved. The multi-scale wavelet decomposition and Hilbert transformation was employed to get the useful parameters such as amplitude, effective value, mean value, kurtosis value and so on of the corresponding waveform to confirm the concrete diagnosis type.

Abstract: Power from wind turbines is mainly related to the wind speed. Due to the influence of the uncertainty of the wind, intermittent and wind farm in units of the wake, wind power has fluctuations. Based on the field measurement, it is found that t location-scale distribution is suitable to identify the probability distribution of wind power variations. By analyzing the fluctuation of a single in different time intervals, we find that the distribution of wind power fluctuation possesses a certain trend pattern. With the length of the time window increasing, the fluctuations increase and some information has been missed. We define an index to calculate the quantity of missing information and can use that to evaluate whether a certain length of interval is acceptable.

Abstract: With the observation data of the whole year from November 2012 to October 2013 and results of numerical simulation, we do some research on the wind energy resources of Henan Province. Variation of wind energy resources is generally better in winter and spring, poor in summer and autumn. Diurnal variation of wind resources across different, but most good wind resource areas are located at higher elevations, and wind resource is generally better at daytime than night. Wind resources of Henan province is relatively limited, which can be technology developed are located in hills area and the mountain highlands of northern, central, western and southern part. Better resources are mainly located on hilltop and ridge.

Abstract: This paper mainly researches on information fusion technology in the application of wind generator state recognition. Set up the model of information fusion based on bayesian theory, and develop status identification system by the platform of Labview. Conduct the test on Drivetrain Diagnosis Simulator (DDS), Simulate the normal and fault condition of wind generator main drive system by using normal and fault gear. Collect the vibration data, extract time domain feature parameters of the vibration signal, and train the identification system with these features. Verify the accuracy of the recognition system through the experiment.

Abstract: Doubly-fed wind power generator takes the largest share of wind energy. However, as the most important part, the speed-up gearbox is easy to be damaged. The existing researches about gearbox faults are mainly about gear fault, the study of bearing fault is relatively less compared with gear fault, expecially for the bearing fault of planet gear. This article presents a typical case of bearing fault about planet gear, which contains the cause of vibration behaviour and the analysis of fault.