scholarly journals Lifetime Estimation Based Health Index and Conditional Factor for Underground Cable System

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8113
Author(s):  
Tanachai Somsak ◽  
Thanapong Suwanasri ◽  
Cattareeya Suwanasri
Keyword(s):  
Estimation Method ◽  
Operating Conditions ◽  
Actual Condition ◽  
Health Index ◽  
Lifetime Estimation ◽  
Scoring Method ◽  
Cable System ◽  
Technical Data ◽  
Underground Cable ◽  
Cable Systems

In this paper, a lifetime estimation method for underground cable systems is proposed by combining a health index (HI) and conditional factor (CF). The underground cable system consists of underground cable, joint, termination, manhole, and duct bank. The HI is an indicator to indicate the actual condition of underground cable components and systems whereas the CF is used to indicate different operating stresses of the system under different operating conditions such as percentage loading, electrical stresses, laying structure, environment, etc. The actual technical data as well as historical operating and testing records are applied. The weighting and scoring method with the analytical hierarchy process are used to classify an importance of underground cable components, testing methods, and criteria used in the HI and CF calculation. The annual calculated HIs are plotted to investigate the lifetime trending curve by using a polynomial function. The degradation curve based on calculated CF is estimated by using the Weibull distribution function. Finally, the remaining life of the underground cable system is determined by matching the lifetime trending curve with the degradation curve. Ten practical underground cable systems supplying power in a high voltage power delivery system are evaluated with effective results. The lifetime of the underground cable system can be successfully estimated.

scholarly journals On the Lifetime Estimation of SiC Power MOSFETs for Motor Drive Applications

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 324
Author(s):  
Carmelo Barbagallo ◽  
Santi Agatino Rizzo ◽  
Giacomo Scelba ◽  
Giuseppe Scarcella ◽  
Mario Cacciato
Keyword(s):  
Electric Drive ◽  
Average Power ◽  
Estimation Procedure ◽  
General Purpose ◽  
Operating Conditions ◽  
Power Losses ◽  
Power Devices ◽  
Lifetime Estimation ◽  
Power Mosfets ◽  
Mission Profile

This work presents a step-by-step procedure to estimate the lifetime of discrete SiC power MOSFETs equipping three-phase inverters of electric drives. The stress of each power device when it is subjected to thermal jumps from a few degrees up to about 80 °C was analyzed, starting from the computation of the average power losses and the commitment of the electric drive. A customizable mission profile was considered where, by accounting the working conditions of the drive, the corresponding average power losses and junction temperatures of the SiC MOSFETs composing the inverter can be computed. The tool exploits the Coffin–Manson theory, rainflow counting, and Miner’s rule for the lifetime estimation of the semiconductor power devices. Different operating scenarios were investigated, underlying their impact on the lifetime of SiC MOSFETs devices. The lifetime estimation procedure was realized with the main goal of keeping limited computational efforts, while providing an effective evaluation of the thermal effects. The method enables us to set up any generic mission profile from the electric drive model. This gives us the possibility to compare several operating scenario of the drive and predict the worse operating conditions for power devices. Finally, although the lifetime estimation tool was applied to SiC power MOSFET devices for a general-purpose application, it can be extended to any type of power switch technology.

scholarly journals STOCHASTIC CARBON EMISSION ESTIMATION METHOD FOR CONSTRUCTION OPERATION

2016 ◽  
Vol 23 (1) ◽  
pp. 137-149 ◽  
Author(s):  
Chang-Yong YI ◽  
Han-Seong GWAK ◽  
Dong-Eun LEE
Keyword(s):  
Carbon Emission ◽  
Performance Metrics ◽  
Ghg Emissions ◽  
Estimation Method ◽  
Operating Conditions ◽  
Analysis Tool ◽  
Micro Scale ◽  
Work Tasks ◽  
Emission Estimation ◽  
Construction Operation

Low carbon construction is an important operation management goal because greenhouse gas (GHG) reduc­tion has become a global concern. Major construction resources that contribute GHG, such as equipment and labour, are being targeted to achieve this goal. The GHG emissions produced by the resources vary with their operating conditions. It is commendable to provide a statistical GHG emission estimation method that models the transitory nature of resource states at micro-scale of construction operations. This paper proposes a computational method called Stochastic Carbon Emission Estimation (SCE2) that measures the variability of GHG emissions. It creates construction operation models consisting of atomic work tasks, utilizes hourly equipment fuel consumption and hourly labourer respiratory rates that change according to their operating conditions classified into five categories, and identifies an optimal resource combi­nation by trading off eco-economic performance metrics such as the amount of GHG emissions, operation completion time, operation completion cost, and productivity. The study is of value to researchers because SCE2 fill in a gap to eco-economic operation modelling and analysis tool which considers operating conditions at micro-scale of construction operation having many stochastic work tasks. This study is also relevance to practitioners because it allows project man­agers to achieve eco-economic goals while honouring predefined constraints associated with time and cost.

Development of On-Line Monitoring System and Aging Characteristics Research of Switchgear

2013 ◽  
Vol 330 ◽  
pp. 364-367
Author(s):  
Shu Xin Liu ◽  
Yun Dong Cao ◽  
Chun Guang Hou ◽  
Yang Liu ◽  
Xiao Ming Liu
Keyword(s):  
Epoxy Resin ◽  
Monitoring System ◽  
Estimation Method ◽  
Current Transformer ◽  
Insulation Material ◽  
Electrical Characteristics ◽  
Infrared Transmission ◽  
Lifetime Estimation ◽  
Monitoring Method ◽  
On Line

For improving reliable operation of switchgear in power system, an approach for on-line monitoring the insulation characteristic and bus-bar temperature rising of the switchgear is proposed in this paper. Through comparing several existing temperature measurement methods for monitoring temperature rising elevation at bus-bas, a new design of temperature monitoring method is proposed. It adopts quick-magnetic saturated current transformer, temperature sensor and infrared transmission to solve the problem of high voltage isolation. The epoxy resin insulation material which is commonly used in switchgear its aging mechanism data is not complete, seriously restrict on-line monitoring for switchgear, so thousands hours of aging experiment is done on switchgear, systematic study various electrical characteristics variation law on the gradual aging process of epoxy resin insulation materials. Therefore, study on the aging characteristics of switchgearinsulation and its lifetime estimation method is the key technology to understand agingmechanism better, search for new fault diagnostic method and the way to extend theuseful lifetime of switchgear. At last, the system runs in real system and the result shows the on-line monitoring system is stable and reliable which can be provide reference for on-line monitoring system design of switchgear.

scholarly journals Dead-end Stop Terminated Tree Support Cable Systems

2011 ◽  
Vol 37 (2) ◽  
pp. 67-73
Author(s):  
E. Thomas Smiley
Keyword(s):  
Support Systems ◽  
System Configuration ◽  
Small Tree ◽  
Cable System ◽  
Risk Of Failure ◽  
Dead End ◽  
Mean Size ◽  
Cable Systems ◽  
The Wire ◽  
Strength Perspective

Supplemental support systems are used to reduce the risk of failure of codominant stems. The goal of this study was to evaluate dead-end stop terminated cables used in trees and to compare the strength of small tree cable systems. Field evaluations comparing eyebolt and Wire Stop® anchored cables found an enlargement of the hole through the branch in 39% of the Wire Stop terminations with a mean size of 6 mm. Static break tests found that the strength of cable system varied with the strength of the wood and system configuration. From a system strength perspective in oak: bent eye screw lags < welded eye screw lag = single swage stop = single swage stop with washer < double swage stop with washer = eyebolt. In pine, bent eye screw lags = welded eye screw lag = single swage stop < single swage stop with washer < double swage stop with washer = double swage stop with fender washer < eyebolt.

Underground Cable Systems

2012 ◽  
pp. 195-237
Author(s):  
Yamille Del Valle ◽  
Nigel Hampton ◽  
Josh Perkel ◽  
Caryn Riley
Keyword(s):  
Underground Cable ◽  
Cable Systems
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