scholarly journals Correlation Characteristic Analysis for Wind Speed in Different Geographical Hierarchies

Energies ◽  
2017 ◽  
Vol 10 (2) ◽  
pp. 237 ◽  
Author(s):  
Shiyu Liu ◽  
Gengfeng Li ◽  
Haipeng Xie ◽  
Xifan Wang
Keyword(s):  
Wind Speed ◽  
Characteristic Analysis ◽  
Correlation Characteristic

Characteristic Analysis on Mountain-Valley Wind in Deep Valley

2012 ◽  
Vol 610-613 ◽  
pp. 817-824
Author(s):  
Wen Yong Wang ◽  
Nan Chen ◽  
Xiao Juan Ma
Keyword(s):  
Wind Speed ◽  
Measured Data ◽  
Characteristic Analysis ◽  
Valley Wind ◽  
Average Wind Speed ◽  
Mountain Valley ◽  
Average Wind ◽  
Slope Wind ◽  
Velocity Circulation ◽  
Thermodynamic Effects

Taking the actual measured data and the simulating result from WRF(Weather Research & Forecasting)/CALMET numerical model, analysing the air flow field in the industrial park in some valley of northern Sichuan Province, it shows that the valley has the mountain-valley wind formed by the topographical thermodynamic effects, and the characters of mountain-valley wind change with season. In January in winter, the valley wind appears at 8:30 in the morning, and prevails after 2 hours transition. The wind strength (wind velocity, circulation height and thickness) is the strongest at about 14:00. The valley wind lasts about 7 hours, and then changes into the mountain wind at 17:30. After 3.5 hours, at 21:00, the mountain wind prevails and lasts 11.5 hours to 8:30 in the next morning. In July in summer, the valley wind appears at 6:30 in the morning. Through 1.5 hours transition, the valley wind prevails at 8:00 and becomes the strongest at 14:00. The valley wind lasts about 10.5 hours and begins to change into the mountain wind at 19:00 in 3 hours. From 22:00 to 6:30 in the next morning, the slope wind prevails and lasts about 8.5 hours. In winter, the thickness for valley wind is bout 100~300m with the average wind speed 1.5~4.0m/s and the thickness for mountain wind is 50~200m with average wind speed 1.5~3.0m/s and circulating sphere height 600~800m. In summer, the valley wind thickness is about 200~500m with average wind speed 2.0~7.0m/s and the mountain wind thickness is about 150~400m with average wind speed 1.5~5m/s and circulation layer height 600~800m. Since the orientation of mountains is different at the both sides of valley, the time and the strength for the mountains receiving the solar radiation are different, the regulation and the characters for mountain-valley wind appearing and disappearing are also different.

scholarly journals Characteristic Analysis of DFIG Wind Turbine under Blade Mass Imbalance Fault in View of Wind Speed Spatiotemporal Distribution

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3178 ◽  
Author(s):  
Shuting Wan ◽  
Kanru Cheng ◽  
Xiaoling Sheng ◽  
Xuan Wang
Keyword(s):  
Wind Speed ◽  
Theoretical Analysis ◽  
Wind Shear ◽  
Natural World ◽  
Spatiotemporal Distribution ◽  
Characteristic Analysis ◽  
Mass Imbalance ◽  
Shadow Effect ◽  
Electromagnetic Power ◽  
Tower Shadow

The blade mass imbalance fault is one of the common faults of the DFIG (Doubly-Fed Induction Generator) wind turbines (WTs). In this paper, considering the spatiotemporal distribution of natural wind speed and the influence of wind shear and tower shadow effect, the influence of blade mass imbalance faults on the electrical characteristics of DFIG WTs is analyzed. Firstly, the analytical expressions and variation characteristics of electromagnetic torque and electromagnetic power under blade mass imbalance are derived before and after consideration of the spatiotemporal distribution of wind speed. Then simulations on the MATLAB/Simulink platform were done to verify the theoretical analysis results. The theoretical analysis and simulation results show that, considering the spatiotemporal distribution of wind speed and the influence of wind shear and tower shadow effect, the blade mass imbalance fault will cause fluctuation at the frequency of 1P (P = the frequency of rotor rotation), 3P, and 6P on electromagnetic power. Fluctuation at 1P is caused by mass imbalance while fluctuation at 3P and 6P are caused by wind speed spatiotemporal distribution; the amplitude of fluctuation at 1P is proportional to the degree of the imbalance fault. Since the equivalent wind speed has been used in this paper instead of the average wind speed, the data is more suitable for the actual operation of the WT in the natural world and can be applied for fault diagnosis in field WT operation.

Correlation characteristic analysis in diversity multiple‐input multiple‐output radar

2017 ◽  
Vol 53 (5) ◽  
pp. 349-351
Author(s):  
Jieyi Liu ◽  
Linrang Zhang ◽  
Shanshan Zhao ◽  
Nan Liu ◽  
Juan Zhang
Keyword(s):  
Multiple Input Multiple Output ◽  
Characteristic Analysis ◽  
Multiple Input ◽  
Correlation Characteristic ◽  
Input Multiple Output

Characteristic Analysis of the Magnetic Field Induced by Ocean Waves and the Filtering Method in Marine Magnetic Survey

2013 ◽  
Vol 860-863 ◽  
pp. 2283-2286
Author(s):  
Xing Le Zhu ◽  
Chang Han Xiao
Keyword(s):  
Magnetic Field ◽  
Wind Speed ◽  
Wavelet Packet ◽  
Ocean Waves ◽  
Magnetic Survey ◽  
Characteristic Analysis ◽  
Similar Frequency ◽  
Filtering Method ◽  
The Magnetic Field ◽  
Magnetizing Field

The filtering method is proposed to diminish magnetic interference caused by ocean waves in marine magnetic survey. Variation characteristic of waves magnetic field about height and wind speed is analysed. Because waves magnetic field has similar frequency band with ships magnetizing field, wavelet packet transform is used to diminish the disturbing effect of wave. Simulation result indicates that the magnetic interference is removed effectively and ship magnetizing filed can be got in high precision, thus the method has great guiding meaning for practical marine magnetic survey.

1842: Catheter Free Potassium-Titanyl-Phosphate (KTP) Laser Photoselective Vaporization Prostatectomy (PVP): Patient Characteristic Analysis

2007 ◽  
Vol 177 (4S) ◽  
pp. 612-612
Author(s):  
Motoo Araki ◽  
Po N. Lam ◽  
Daniel J. Culkin ◽  
Pamela E. Fox ◽  
Glenn M. Sulley ◽  
...  
Keyword(s):  
Potassium Titanyl Phosphate ◽  
Ktp Laser ◽  
Characteristic Analysis ◽  
Photoselective Vaporization
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