VHF-UHF帯電波干渉計システムによる部分放電源特定のための基礎研究

Abstract

The electromagnetic waves emitted from partial discharge (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 VHF-UHF radio interferometer system (VURIS) for locating PD source has been originally designed, constructed and tested. The system is based on the idea extracting the phase differences at different frequencies between a pair of the received signals by the Fourier transform and computing the direction of the electromagnetic waves emitted from PD source. It can be small-sized, more suitable for compact and portable system, because UHF half-wavelength dipole antennas are used to receive the electromagnetic waves and the baseline between the antennas is very short. And it requires fewer antennas to achieve equivalent angular resolution than a narrow band interferometer system, which requires multiple baselines corresponding to a few times of half-wavelength of the observation frequency. Therefore, it's able to reduce the operating time at the measurement site because it's not needed to arrange many antennas at the many points. The indoor test results indicate that the system is able to estimate the arrival angle of the electromagnetic waves emitted from PD source.