KIEE International Transactions on Electrophysics and Applications

The Korean Institute of Electrical Engineers (대한전기학회)
권호 표지

Multistress Life Models of Epoxy Encapsulated Magnet wire under High Frequency Pulsating Voltage

  • Grzybowski, S. (High Voltage Laboratory Mississippi State University) ;
  • Feilat, E.A. (Dept. of Electrical and Electronic Engineering, Chungnam National University) ;
  • Knight, P. (Thomson Consumer Electronics)
  • Published : 2003.01.01
Download PDF
⟨ Previous Next ⟩

Abstract

This paper presents an attempt to develop probabilistic multistress life models to evaluate the lifetime characteristics of epoxy-encapsulated magnet wire with heavy build polyurethane enamel. A set of accelerated life tests were conducted over a wide range of pulsating voltages, temperatures, and frequencies. Samples of fine gauge twisted pairs of the encapsulated magnet wire were tested us-ing a pulse endurance dielectric test system. An electrical-thermal lifetime function was combined with the Weibull distribution of lifetimes. The parameters of the combined Weibull-electrical-thermal model were estimated using maximum likelihood estimation. Likewise, a generalized electrical-thermal-frequency life model was also developed. The parameters of this new model were estimated using multiple linear regression technique. It was found in this paper that lifetime estimates of the two proposed probabilistic multistress life models are good enough. This suggests the suitability of using the general electrical-thermal-frequency model to estimate the lifetime of the encapsulated magnet wire over a wide range of voltages, temperatures and pulsating frequencies.

Keywords

References

  1. Cygan, P., Laghari, J. R., Models for Insulation Aging under Electrical and Thermal Multistress, IEEE Trans. on Electrical Insulation, Vol EI-25, No.5, October 1990, pp. 923-934
  2. Montanari, G. C., Cacciari, M., A Probabilistic Insulation Life Model for Combined Thermal-Electrical Stresses, IEEE Trans. on Electrical Insulation, Vol El-20, No.3, June 1985, pp. 519-522
  3. Stone, G. C., The Application of Weibull Statistics to Insulation Aging Tests, IEEE Trans. on Electrical Insulation, Vol EI- 14, No.5, 1979, pp. 233-239
  4. Lawless, J. F., Statistical Models and Methods for Lifetime Data, J. Wiley and Sons, New York, 1982
  5. Grzybowski, S., Dobroszewski, R., Grzegorski, E., Accelerated Endurance Tests of Polyethylene Insulated Cables, 3rd International Conference on Dielectric Materials, Measurements and Applications, September 10-13, 1979, Birmingham, UK, pp. 120-123
  6. Fothergill, J. C., Estimating the Cumulative Probability of Failure Data Points to be Plotted on Weibull and other Probability Papers, IEEE Trans. on Electrical Insulation, Vol EI-25, No.3, June 1990, pp. 489-492
  7. Feilat, E. A., Grzybowski, S., Knight, P., Multiple Stress Aging of Magnet Wire by High Frequency Voltage Pulses and High Temperatures, Conference Records of the 2000 IEEE International Symposium on Electrical Insulation (ISEI2000), Anaheim, CA, April 2-5, 2000, pp. 157-160
  8. Beeckman, R. J., Harber, J. J., Wentz, S. J., Studies on Magnet Wire Degradation with Inverter Driven Motors, Proc. of Electrical Electronics Insulation Conference, Rosemont, Illinois, September 1997, pp. 387-383