Fundamental study on location of a partial discharge source with a VHF‐UHF radio interferometer system

Abstract

AbstractThe electromagnetic waves emitted from partial discharges (PD) due to material defects in high‐voltage electric power apparatus and facilities are broadband signals including VHF, UHF (Very High Frequency, Ultra High Frequency). A new VHF‐UHF radio interferometer system (VURIS) for locating PD source has been designed, constructed, and tested. The system is based on the idea of using the Fourier transform to extract the phase differences of different frequency components between a pair of received signals and computing the direction of the electromagnetic waves emitted from the PD source. It can be small in size, because UHF half‐wavelength dipole antennas are used to receive the electromagnetic waves and the baseline between the antennas is short. It requires fewer antennas to achieve equivalent angular resolution than a narrow‐band interferometer system, which requires multiple baselines corresponding to a few times the half‐wavelength of the observation frequency. Therefore, its use reduces operating time at the measurement site because it is not necessary to arrange many antennas at many positions. The indoor test results indicate that the system is able to estimate the arrival angle of electromagnetic waves emitted from PD sources. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 144(1): 32–41, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10145