scholarly journals Research on damage mechanism of bearing current in high power motor

2017 ◽  
Vol 12 ◽  
pp. 61-65
Author(s):  
Guangbin Wang ◽  
Long Li ◽  
Xianwen Meng
Keyword(s):  
High Power ◽  
Damage Mechanism ◽  
Bearing Current

Study of the thermal damage mechanism in the discharge of high power xenon lamp

2017 ◽  
Author(s):  
Xiangchao Guo ◽  
Jianjun Liu ◽  
Haibing Li ◽  
Ruihua Wu ◽  
Ruoyan Shao ◽  
...  
Keyword(s):  
High Power ◽  
Thermal Damage ◽  
Damage Mechanism ◽  
Xenon Lamp

Prediction of bearing damage in wind turbines based on the quadratic root mean square of sub-band manifold

2017 ◽  
Vol 232 (18) ◽  
pp. 3213-3223 ◽  
Author(s):  
Wang Guangbin ◽  
Du Moujun ◽  
Huang Liangpei ◽  
Li Long
Keyword(s):  
Wind Turbine ◽  
Root Mean Square ◽  
High Power ◽  
Prediction Method ◽  
Multiple Point ◽  
Mean Square ◽  
Time Frequency ◽  
Damage Characteristics ◽  
Bearing Current ◽  
Propagation Network

When a high-power wind turbine runs in normal status, and if bearing current exists for a long time, multiple point corrosion would occur and gradually increase, eventually forming a ripple groove on the inner ring race, outer ring race and rolling body. It would lead to more vibration and shock, thereby causing fault in the equipment; the best way to prevent the this kind of fault is to find the effective fault characteristics and predict the damage’s degree on the bearing. In this paper, an adaptive neural network prediction method based on the quadratic root mean square of sub-band manifold is proposed. The damage characteristics can be analyzed by following steps: firstly, the vibration signal is decomposed into multidimensional time frequency space by wavelet packet method. Secondly, the sub-band of the manifold is constructed. The third step is to extract the root mean square value. Finally, the damage characteristics of the bearing current of the two square root sub-band manifold are obtained. Based on the back propagation network, the adaptive prediction model is built, and the training speed could be adjusted automatically according to the prediction error and precision. According to the bearing’s fault mechanism with current damage on the high-power wind turbine, one fault experiment platform has been built to simulate the current damage process of the bearing and verify the prediction method based on the quadratic root mean square of sub-band manifold. The experimental results show that the method can effectively predict the degree of bearing current damage, and the relative error of prediction is less than 5%.

scholarly journals High power microwave damage mechanism on high electron mobility transistor

2016 ◽  
Vol 65 (16) ◽  
pp. 168501
Author(s):  
Li Zhi-Peng ◽  
Li Jing ◽  
Sun Jing ◽  
Liu Yang ◽  
Fang Jin-Yong
Keyword(s):  
High Power ◽  
Electron Mobility ◽  
High Electron Mobility Transistor ◽  
Damage Mechanism ◽  
High Electron ◽  
High Electron Mobility ◽  
High Power Microwave ◽  
Power Microwave

Thermal damage mechanism of xenon lamp silica envelope during high-power discharge

2014 ◽  
Vol 26 (8) ◽  
pp. 82004
Author(s):  
刘建军 Liu Jianjun ◽  
李海兵 Li Haibing ◽  
郭向朝 Guo Xiangchao ◽  
吴睿骅 Wu Ruihua ◽  
邵若燕 Shao Ruoyan ◽  
...  
Keyword(s):  
High Power ◽  
Thermal Damage ◽  
Damage Mechanism ◽  
Xenon Lamp

Study of Damage Mechanism of High Power Microwave on Electronic Equipments

2008 ◽  
Author(s):  
Xiao Jinshi ◽  
Liu Wenhua ◽  
Zhang Shiying ◽  
Zhang Jinhua ◽  
Xing Changfeng
Keyword(s):  
High Power ◽  
Damage Mechanism ◽  
High Power Microwave ◽  
Power Microwave

Elemental mass loss in silicate minerals during x-ray analysis

1990 ◽  
Vol 48 (4) ◽  
pp. 804-805
Author(s):  
P.E. Champness ◽  
R.W. Devenish
Keyword(s):  
Mass Loss ◽  
Current Density ◽  
Damage Mechanism ◽  
Beam Current ◽  
Single Chain ◽  
Plagioclase Feldspar ◽  
X Ray ◽  
Alkali Ions ◽  
Structural Order ◽  
Sheet Silicate

It has long been recognised that silicates can suffer extensive beam damage in electron-beam instruments. The predominant damage mechanism is radiolysis. For instance, damage in quartz, SiO2, results in loss of structural order without mass loss whereas feldspars (framework silicates containing Ca, Na, K) suffer loss of structural order with accompanying mass loss. In the latter case, the alkali ions, particularly Na, are found to migrate away from the area of the beam. The aim of the present study was to investigate the loss of various elements from the common silicate structures during electron irradiation at 100 kV over a range of current densities of 104 - 109 A m−2. (The current density is defined in terms of 50% of total current in the FWHM probe). The silicates so far ivestigated are:- olivine [(Mg, Fe)SiO4], a structure that has isolated Si-O tetrahedra, garnet [(Mg, Ca, Fe)3Al2Si3AO12 another silicate with isolated tetrahedra, pyroxene [-Ca(Mg, Fe)Si2O6 a single-chain silicate; mica [margarite, -Ca2Al4Si4Al4O2O(OH)4], a sheet silicate, and plagioclase feldspar [-NaCaAl3Si5O16]. Ion- thinned samples of each mineral were examined in a VG Microscopes UHV HB501 field- emission STEM. The beam current used was typically - 0.5 nA and the current density was varied by defocussing the electron probe. Energy-dispersive X-ray spectra were collected every 10 seconds for a total of 200 seconds using a Link Systems windowless detector. The thickness of the samples in the area of analysis was normally 50-150 nm.

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