Investigations into the upgrading of existing HVAC power transmission circuits for higher power transfers using HVDC technology

2006 ◽  
Author(s):  
P. Naidoo ◽  
D. Muftic ◽  
N. Ijumba
Keyword(s):  
Power Transmission ◽  
Higher Power

scholarly journals Simulation of 2-Coil and 4-Coil Magnetic Resonance Wearable WPT Systems

Proceedings ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 13
Author(s):  
Yixuan Sun ◽  
Stephen Beeby
Keyword(s):  
Power Efficiency ◽  
Power Transmission ◽  
Rotation Angle ◽  
Wireless Power ◽  
Peak Efficiency ◽  
Frequency Splitting ◽  
At Resonance ◽  
Higher Power ◽  
The Impact ◽  
Proper Frequency

This paper presents the COMSOL simulations of magnetically coupled resonant wireless power transfer (WPT), using simplified coil models for embroidered planar two-coil and four-coil systems. The power transmission of both systems is studied and compared by varying the separation, rotation angle and misalignment distance at resonance (5 MHz). The frequency splitting occurs at short separations from both the two-coil and four-coil systems, resulting in lower power transmission. Therefore, the systems are driven from 4 MHz to 6 MHz to analyze the impact of frequency splitting at close separations. The results show that both systems had a peak efficiency over 90% after tuning to the proper frequency to overcome the frequency splitting phenomenon at close separations below 10 cm. The four-coil design achieved higher power efficiency at separations over 10 cm. The power efficiency of both systems decreased linearly when the axial misalignment was over 4 cm or the misalignment angle between receiver and transmitter was over 45 degrees.

Research on Dual-Cones CVT Based on EHL

2011 ◽  
Vol 308-310 ◽  
pp. 1929-1934
Author(s):  
Hui Li Dong ◽  
Shi Hua Yuan ◽  
Chao Wei
Keyword(s):  
Film Thickness ◽  
High Speed ◽  
Power Transmission ◽  
Elastohydrodynamic Lubrication ◽  
Face To Face ◽  
Dual Cones ◽  
Higher Power ◽  
Minimum Film Thickness ◽  
Traction Coefficient ◽  
Increasing Load

A novel configuration of CVT that contains two cones located in the same shaft face to face is researched about the traction performance under high speed based on the theory of elastohydrodynamic lubrication(EHL). The effects of load, radii of curvature and slip-roll ratio on the traction characteristics and power transmission are analyzed. The results show that with increasing load the traction coefficient enhances close to linearly where the load is not heavy and the minimum film thickness decreases linearly when the inner wheel radii of curvature less than 0.085m. The leftmost position could transmit higher power. The power transmitted improves slightly as slip-roll ratio enhances in an appropriate range.

New calculation method for the scuffing load-carrying capacity of bevel and hypoid gears

2019 ◽  
Vol 233 (21-22) ◽  
pp. 7328-7337 ◽  
Author(s):  
J Pellkofer ◽  
I Boiadjiev ◽  
D Kadach ◽  
M Klein ◽  
K Stahl
Keyword(s):  
Carrying Capacity ◽  
Calculation Method ◽  
Power Transmission ◽  
Field Application ◽  
Load Carrying Capacity ◽  
Hypoid Gears ◽  
Tribological System ◽  
Higher Power ◽  
Load Carrying ◽  
Tooth Flank

Future trends indicate that the demands on bevel and hypoid gears for higher power transmission and lower weight are continuously increasing. Beside typical fatigue failures such as pitting, tooth root breakage, and tooth flank fracture, spontaneous failures such as scuffing are often observed if the load-carrying capacity of the tribological system consisting of gears and lubricant is exceeded. This paper gives an overview of the newest findings on scuffing specifically on bevel and hypoid gears and discusses the hypoid-specific decisive influence parameters. Furthermore, the newly developed calculation method as well as its verification with test results and results from field application are presented.

Physical Fitness and Resting EEG in Children With Attention Deficit Hyperactivity Disorder

2015 ◽  
Vol 29 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Ching-Wen Huang ◽  
Chung-Ju Huang ◽  
Chiao-Ling Hung ◽  
Chia-Hao Shih ◽  
Tsung-Min Hung
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Physical Fitness ◽  
Attention Deficit ◽  
Resting State ◽  
Self Control ◽  
Children With Adhd ◽  
Hyperactivity Disorder ◽  
Higher Power ◽  
Eyes Open ◽  
The Relationship

Children with attention deficit hyperactivity disorder (ADHD) are characterized by a deviant pattern of brain oscillations during resting state, particularly elevated theta power and increased theta/alpha and theta/beta ratios that are related to cognitive functioning. Physical fitness has been found beneficial to cognitive performance in a wide age population. The purpose of the present study was to investigate the relationship between physical fitness and resting-state electroencephalographic (EEG) oscillations in children with ADHD. EEG was recorded during eyes-open resting for 28 children (23 boys and 5 girls, 8.66 ± 1.10 years) with ADHD, and a battery of physical fitness assessments including flexibility, muscular endurance, power, and agility tests were administered. The results indicated that ADHD children with higher power fitness exhibited a smaller theta/alpha ratio than those with lower power fitness. These findings suggest that power fitness may be associated with improved attentional self-control in children with ADHD.

Using the ARTIST approach for diagnosing power transmission networks

1994 ◽  
Vol 3 (3) ◽  
pp. 125 ◽  
Author(s):  
R. Leitch ◽  
H. Freitag ◽  
A. Stefanini ◽  
G. Tornielli
Keyword(s):  
Power Transmission ◽  
Transmission Networks ◽  
Power Transmission Networks
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