Weibull statistics in electrical aging of polyesterimide under AC voltage

Nedjar, Mohammed; Béroual, Abderrahmane

doi:10.1002/app.31509

Cited by 6 publications

(4 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In cylindrical conductors with thin insulation layer, the insulation layer may act as a catalyst to the thermal process where it will deteriorate over time when heat is applied. Copper conductor's insulation layer does not have an oxide layer to prevent diffusion [11] or melting of the joint point between two conductors, and this phenomenon tends to occur in all copper materials. No inter-short failures among the copper conductor where observed when thermal resistance was applied at 420±5 degree Celsius.…”

Section: Resultsmentioning

confidence: 99%

A Comparative Analysis of Inductors with Square and Conical Contours

Khoo

Ovinis

Thirumalaiswamy

2013

AMM

View full text Add to dashboard Cite

Winding pattern and contour are important factors in power inductors with multiple layer windings, since power inductors with multiple layers are prone to proximity effect, as multiple stacking increases the resistance stress of a conductor, eventually leading to failure of the inductor. This paper presents a comparison of winding losses for cone and square contour inductors, and discusses possible causes for the discrepancy. Conical contour inductors within a fixed core window are comparatively better than square contour winding inductors. A cross sectional analysis after winding revealed that the conical contour inductor has a gap between the conductors, indicating no melting and diffusion between layers. The absence of diffusion due to thermal degradation in conical contour winding is believed to be due to the conductor skin thickness, which is on average smaller, owing to the lower winding stresses. For a fixed dimension core and number of turns, winding losses can be reduced using a cone-shape contour compared to a square-shape contour

show abstract

Section: Resultsmentioning

confidence: 99%

A Comparative Analysis of Inductors with Square and Conical Contours

Khoo

Ovinis

Thirumalaiswamy

2013

AMM

View full text Add to dashboard Cite

show abstract

“…This application consists of testing the adjustment of an observed distribution with a theoretical distribution. This test was applied by many authors in the study of the dielectric breakdown of polymers [20,21,26]. The procedure was as follows:…”

Section: Statistical Analysis Of Breakdown Voltage Datamentioning

confidence: 99%

“…Indeed, in this work, the experiments were executed on a large number of specimens, and the values of breakdown were statistically analyzed by the two-parameter Weibull distribution. This analysis is widely used to characterize the dielectric failure of polymers [8,20,21].…”

Section: Introductionmentioning

confidence: 99%

Statistical study on short-term dielectric breakdown of poly(vinyl chloride)

Nedjar

2013

J Vinyl Addit Technol

Self Cite

View full text Add to dashboard Cite

This paper reports the breakdown voltage of plasticized poly(vinyl chloride) under AC and DC electric fields. The effect of ramp rate on breakdown voltage was investigated. A statistical analysis of breakdown data was carried out by using the two‐parameter Weibull distribution. The best linear fit was determined by an estimation based on the method of maximum likelihood. The 90% confidence intervals of Weibull plots were calculated, and the model was validated by the χ2 test. The study showed that the shape parameter varied with ramp rate. This result could be explained by the evolution of defect number and size. Breakdown voltage increased with ramp speed. This phenomenon was attributed to the time necessary for the accumulation of defects and charges to form a breakdown path. Breakdown voltage was higher under a DC field. This increase was due to the difference in dissipated energy under the two types of field and to the fatigue produced by AC stress. The DC breakdown voltage was greater under negative polarity. This finding was ascribed to the ratio difference of space charge accumulated under the two polarities. J. VINYL ADDIT. TECHNOL., 19:177‐182, 2013. © 2013 Society of Plastics Engineers

show abstract

“…Therefore, a statistical analysis is highly useful. Among the statistical models, the Weibull distribution is preferred and widely applied to analyse dielectric breakdown data [15][16][17].…”

mentioning

confidence: 99%

Weibull Statistics in Dielectric Strength of Oil-impregnated Pressboard under Ramped AC and DC Voltages

Nedjar¹

2013

JEPE

View full text Add to dashboard Cite

AC and DC breakdown tests were performed on large populations of oil-impregnated pressboard samples. The effect of voltage ramp rate on dielectric strength has been investigated. A statistical analysis of breakdown data was carried out using the Weibull distribution. The 90% confidence intervals of Weibull graphs were calculated. The study shows that dielectric strength and shape parameter change versus ramp rate. The variations are attributed to the size and number of defects. Discharges occur from the oil to the oil-pressboard interface and lead to breakdown. DC dielectric strength is larger than that corresponding to AC voltage. This is ascribed to the dissipated energy difference under the two types of field and the fatigue produced by the alternating voltage. This phenomenon is related to space charge. Under DC stress, dielectric strength is higher under negative polarity. It is assigned to the different quantities of space charge accumulated under the two polarities.

show abstract

Weibull statistics in electrical aging of polyesterimide under AC voltage

Cited by 6 publications

References 13 publications

A Comparative Analysis of Inductors with Square and Conical Contours

A Comparative Analysis of Inductors with Square and Conical Contours

Statistical study on short-term dielectric breakdown of poly(vinyl chloride)

Weibull Statistics in Dielectric Strength of Oil-impregnated Pressboard under Ramped AC and DC Voltages

Contact Info

Product

Resources

About