scholarly journals Anomaly Detection and Degradation Prediction of MOSFET

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Li-Feng Wu ◽  
Yong Guan ◽  
Xiao-Juan Li ◽  
Jie Ma
Keyword(s):  
Experimental Data ◽  
Early Warning ◽  
Power Electronic ◽  
Degradation Model ◽  
Electrical Systems ◽  
Performance Of Systems ◽  
Failure Models ◽  
Degree Of Degradation ◽  
Degradation State ◽  
Failure Precursor

The MOSFET is an important power electronic transistor widely used in electrical systems. Its reliability has an effect on the performance of systems. In this paper, the failure models and mechanisms of MOSFETs are briefly analyzed. The on-resistanceRonis the key failure precursor parameter representing the degree of degradation. Based on the experimental data, a nonlinear dual-exponential degradation model for MOSFETs is obtained. Then, we present an approach for MOSFET degradation state prediction using a strong tract filter based on the obtained degradation model. Lastly, the proposed algorithm is shown to perform effectively on experimental data. Thus, it can provide early warning and enhance the reliability of electrical systems.

scholarly journals A Combined Multiple Factor Degradation Model and Online Verification for Electric Vehicle Batteries

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4376 ◽  
Author(s):  
Yuan Chen ◽  
Yigang He ◽  
Zhong Li ◽  
Liping Chen
Keyword(s):  
Experimental Data ◽  
Electric Vehicle ◽  
Factor Model ◽  
Capacity Fade ◽  
State Of Health ◽  
Degradation Model ◽  
Multiple Factors ◽  
Battery Degradation ◽  
Total Capacity ◽  
Multiple Factor

Battery state of health (SOH) is related to the reduction of total capacity due to complicated aging mechanisms known as calendar aging and cycle aging. In this study, a combined multiple factor degradation model was established to predict total capacity fade considering both calendar aging and cycle aging. Multiple factors including temperature, state of charge (SOC), and depth of discharge (DOD) were introduced into the general empirical model to predict capacity fade for electric vehicle batteries. Experiments were carried out under different aging conditions. By fitting the data between multiple factors and model parameters, battery degradation equations related to temperature, SOC, and DOD could be formulated. The combined multiple factor model could be formed based on the battery degradation equations. An online state of health estimation based on the multiple factor model was proposed to verify the correctness of the model. Predictions were in good agreement with experimental data for over 270 days, as the margin of error between the prediction data and the experimental data never exceeded 1%.

Multi-Axial Fatigue Damage Models of Fiber Reinforced Composites

2004 ◽  
Author(s):  
N. H. Yang ◽  
H. Nayeb-Hashemi ◽  
A. Vaziri
Keyword(s):  
Experimental Data ◽  
Fatigue Life ◽  
Fatigue Damage ◽  
Fatigue Failure ◽  
Multiaxial Fatigue ◽  
Loading Frequency ◽  
Reinforced Composites ◽  
Damage Models ◽  
Failure Models ◽  
Axial Fatigue

Fiberglass reinforced composites are extensively used in various structural components. In order to insure their structural integrity, their monotonic and fatigue properties under multiaxial stress fields must be understood. Combined in-phase tension/torsion loading is applied to [±45°]4 E-glass/epoxy composite tubes under monotonic and fatigue conditions to determine the effects of multiaxial loading on its failure. Various monotonic and fatigue damage criteria are proposed. These models considered failure mode (failure plane), the energy method and the effective stress-strain method. It is observed for the majority of experiments, the failure initiated at the outer lamina layer at 45° to the tube axis. A damage criterion for multiaxial monotonic loading is proposed considering both normal and shear stress contributions on the plane of failure. The experimental data show an excellent agreement with this proposed model for various loading conditions. Other failure models are currently under investigation utilizing the stresses and strains at the composite laminate as well as stress and strain at the outer lamina layer. Multiaxial fatigue failure models are proposed considering again the plane of failure. Since the plane of the failure is subjected to mean and cyclic stresses (shear and normal) and mean and cyclic strains (shear and normal), the fatigue damage models consider the contributions of these stresses and strains to the fatigue life of the composite tube. In addition to the fatigue damage model based on the plane of failure, a multi-axial fatigue failure model is proposed considering the mean and cyclic energy during fatigue experiments. The experimental data show a good correlation between the proposed damage parameters and fatigue life of specimens with some scatter of the data. Other fatigue failure models are currently under investigation considering the loading frequency and visco-elastic properties of the composite.

scholarly journals Voltage Degradation Model of Thin Film Capacitors

1985 ◽  
Vol 12 (1) ◽  
pp. 63-70
Author(s):  
T. M. Berlicki
Keyword(s):  
Thin Film ◽  
Experimental Data ◽  
Breakdown Voltage ◽  
Short Term ◽  
Degradation Model ◽  
Damage Rate ◽  
Thin Film Capacitors ◽  
Voltage Degradation ◽  
Critical Damage

A degradation model of thin film capacitors is presented. This model takes into consideration that: (a) the damage rate dD/dt is a function of the damage value D, and (b) the critical damage Dcis a function of working voltage. On the base of this model, the short term breakdown voltage and its distribution is defined. The experimental data presented conforms with the described model.

scholarly journals Protecting The Supply Chain: Differentiating Large And Small Suppliers

2011 ◽  
Vol 7 (10) ◽  
Author(s):  
Harlan Platt ◽  
Marjorie Platt
Keyword(s):  
Supply Chain ◽  
Predictive Model ◽  
Early Warning ◽  
Predictive Models ◽  
Chain Structure ◽  
Font Size ◽  
Key Factors ◽  
History Of ◽  
Failure Models ◽  
Supply Chain Structure

<p class="MsoNormal" style="text-align: justify; margin: 0in 0.5in 0pt; mso-layout-grid-align: none;"><span style="font-size: 10pt;"><span style="font-family: Times New Roman;">This paper recounts the history of early warning failure models and then adds to that literature by evaluating the proposition that all suppliers can be treated similarly when evaluating failure tendencies. The work is performed for the automobile supplier industry because that industry has a long and complex supply chain structure and because we have a history of working with major automotive OEMs to protect their supply chain. The project benefited from the support and cooperation of BBK Ltd. the largest turnaround firm worldwide engaged by the automobile sector. In contrast to previous work which utilized a single predictive model to indicate the likelihood that a supplier company was in distress, our effort tested the idea that large and small automobile suppliers face different exigencies and therefore require separate predictive models. The paper concludes by identifying the key factors to consider when reviewing the health of automobile suppliers.</span></span></p>

Prognosis of Failure Precursor in Complex Electrical Systems Using Symbolic Dynamics

2007 ◽  
Author(s):  
Ravindra Patankar ◽  
Venkatesh Rajagopalan ◽  
Devendra Tolani ◽  
Asok Ray ◽  
Michael Begin
Keyword(s):  
Symbolic Dynamics ◽  
Electrical Systems ◽  
Failure Precursor

scholarly journals Wear Calculation-Based Degradation Analysis and Modeling for Remaining Useful Life Prediction of Ball Screw

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Li Zhang ◽  
Hongli Gao ◽  
Dawei Dong ◽  
Guoqiang Fu ◽  
Qi Liu
Keyword(s):  
Experimental Data ◽  
Remaining Useful Life ◽  
Ball Screw ◽  
Wear Volume ◽  
Degradation Model ◽  
Volume Formula ◽  
Proposed Model ◽  
Degradation Analysis ◽  
Wear Calculation ◽  
Useful Life

Ball screw is a kind of precise transmission element in drive system of machine tool. In this paper, the degradation model of ball screw is proposed based on wear calculation-based degradation analysis and experimental data-based validation. At first, fatigue wear is analyzed to be the predominant degradation mode of ball screw. The wear volume formula of ball screw is derived as the function of working load and stroke number. Secondly, the degradation rate of ball screw is analyzed to be affected by the total degradation and wear rate. Based on this finding, the degradation model of ball screw is theoretically derived as an exponential model by inputting wear volume formula. Thirdly, experimental data-based cross-validation method is proposed to validate the exponential degradation model. Determination coefficients are calculated to evaluate the fitting degree between the degradation model and real degradation path. Next, run-to-failure test of ball screw is carried out to collect experimental data in different working conditions. The average determination coefficient of different working conditions is calculated as 0.7848, which indicates that the proposed model can well fit the actual degradation path. In addition, the proposed model is applied to predict remaining useful life (RUL) of the tested ball screw by using collected data. RUL is estimated in a high and stable accuracy after 168000 strokes. For further validation, comparison with linear model is performed. All results show that the exponential degradation model is reasonable and correct in reflecting the degradation process of ball screw.

scholarly journals A Review of Total Harmonic Distortion Factors for the Measurement of Harmonic and Interharmonic Pollution in Modern Power Systems

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6467
Author(s):  
Angel Arranz-Gimon ◽  
Angel Zorita-Lamadrid ◽  
Daniel Morinigo-Sotelo ◽  
Oscar Duque-Perez
Keyword(s):  
Power Systems ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Electronic Systems ◽  
International Electrotechnical Commission ◽  
Power Electronic ◽  
Electrical System ◽  
Electrical Systems ◽  
Wide Range

Harmonic distortion is one of the disturbances that most affects the quality of the electrical system. The widespread use of power electronic systems, especially power converters, has increased harmonic and interharmonic emission in a wide range of frequencies. Therefore, there are new needs in the measurement of harmonic distortion in modern electrical systems, such as measurement in the supra-harmonic range (>2 kHz) and the measurement of interharmonics. The International Electrotechnical Commission (IEC) standards define new total harmonic distortion (THD) rates based on the concept of frequency groupings. However, the rates defined in the IEC standards have shortcomings when measuring signals such as those present in the outputs of power systems with abundant interharmonic content and presence of components in the supra-harmonic range. Therefore, in this work, a comparison is made between the different THD factors currently defined, both in the literature and in the standards, to show which of them are the most suitable for assessing harmonic and interharmonic contamination in power system signals such as those present at the output of inverters.

scholarly journals KNN algorithm of early warning system for applied research course

2020 ◽  
Vol 218 ◽  
pp. 01030
Author(s):  
Zian Li ◽  
Cui Zhao
Keyword(s):  
Experimental Data ◽  
Basic Principle ◽  
Early Warning ◽  
Early Warning System ◽  
Applied Research ◽  
Warning System ◽  
System Model ◽  
Manhattan Distance ◽  
Paper Briefly ◽  
Basic Experimental Data

This paper designed a small course early warning system based on KNN algorithm, aimed at students haven’t finished the course of time can be completed by yourself some predict their courses by chance. In this paper, the basic principle of KNN algorithm is briefly introduced, and the course warning system is modified by Manhattan distance with added weights. This paper briefly describes the basic framework of this model and introduces the application of KNN algorithm in this model. Through a large number of basic experimental data to test the training, using figures to show, finally get the curriculum early warning system model, to achieve the effect of curriculum early warning.

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