Publication detail

Noise Diagnostics of Insulating Materials for Operation at High Temperature

KOKTAVÝ, P., ŠIKULA, J., KOKTAVÝ, B., LIEDERMANN, K.

Original Title

Noise Diagnostics of Insulating Materials for Operation at High Temperature

English Title

Noise Diagnostics of Insulating Materials for Operation at High Temperature

Type

conference paper

Language

en

Original Abstract

The samples of insulation materials for operation at temperatures to 350 oC were tested in a high electric field. Tested materials covered with metal electrodes on both sides represent a parallel plate capacitor. The VA characteristics are proportional to U^n where n ~ 1. Partial discharges have an impact on conductivity at a high electric field and they are important sources of noise and acoustic emission signals. This phenomenon is related to the sample homogeneity and may be used for technology assessment and quality testing. The electromagnetic signal precedes the acoustic emission response and the time delay corresponds to the difference of propagation velocities of sound and electromagnetic radiation in the sample. This phenomenon may be used for the localization of voids in an insulator. A current pulse generated by a random discharge in a void within the insulator is represented by an exponentially decreasing function, whereas the acoustic signal exhibits a quasiperiodic damped behavior. Statistic characteristics of the impulse amplitudes of acoustic emission and partial discharges and their correlation are studied. The characteristics of studied materials depend on temperature and applied voltage. The methodology presented above serves for a non-destructive evaluation of insulators for power apparatuses working at high temperatures and at high voltages.

English abstract

The samples of insulation materials for operation at temperatures to 350 oC were tested in a high electric field. Tested materials covered with metal electrodes on both sides represent a parallel plate capacitor. The VA characteristics are proportional to U^n where n ~ 1. Partial discharges have an impact on conductivity at a high electric field and they are important sources of noise and acoustic emission signals. This phenomenon is related to the sample homogeneity and may be used for technology assessment and quality testing. The electromagnetic signal precedes the acoustic emission response and the time delay corresponds to the difference of propagation velocities of sound and electromagnetic radiation in the sample. This phenomenon may be used for the localization of voids in an insulator. A current pulse generated by a random discharge in a void within the insulator is represented by an exponentially decreasing function, whereas the acoustic signal exhibits a quasiperiodic damped behavior. Statistic characteristics of the impulse amplitudes of acoustic emission and partial discharges and their correlation are studied. The characteristics of studied materials depend on temperature and applied voltage. The methodology presented above serves for a non-destructive evaluation of insulators for power apparatuses working at high temperatures and at high voltages.

RIV year

2001

Released

22.10.2001

Publisher

University of Florida, Gainesville, Florida, USA

Location

Gainesville, Florida, USA

ISBN

981-02-4677-3

Book

Proceedings of ICNF 2001

Edition number

1

Pages from

759

Pages to

762

Pages count

4

BibTex


@inproceedings{BUT6807,
  author="Pavel {Koktavý} and Josef {Šikula} and Bohumil {Koktavý} and Karel {Liedermann}",
  title="Noise Diagnostics of Insulating Materials for Operation at High Temperature",
  annote="The samples of insulation materials for operation at temperatures to 350 oC were tested in a high electric field. Tested materials covered with metal electrodes on both sides represent a parallel plate capacitor. The VA characteristics are proportional to U^n where n ~ 1. Partial discharges have an impact on conductivity at a high electric field and they are important sources of noise and acoustic emission signals. This phenomenon is related to the sample homogeneity and may be used for technology assessment and quality testing. The electromagnetic signal precedes the acoustic emission response and the time delay corresponds to the difference of propagation velocities of sound and electromagnetic radiation in the sample. This phenomenon may be used for the localization of voids in an insulator. A current pulse generated by a random discharge in a void within the insulator is represented by an exponentially decreasing function, whereas the acoustic signal exhibits a quasiperiodic damped behavior. Statistic characteristics of the impulse amplitudes of acoustic emission and partial discharges and their correlation are studied. The characteristics of studied materials depend on temperature and applied voltage. The methodology presented above serves for a non-destructive evaluation of insulators for power apparatuses working at high temperatures and at high voltages.",
  address="University of Florida, Gainesville, Florida, USA",
  booktitle="Proceedings of ICNF 2001",
  chapter="6807",
  institution="University of Florida, Gainesville, Florida, USA",
  year="2001",
  month="october",
  pages="759",
  publisher="University of Florida, Gainesville, Florida, USA",
  type="conference paper"
}