No abstract

A locating system based on an advanced time difference of arrival (TDOA) estimation method is developed to locate the position of a discharge source to avoid pulsed electromagnetic interference (PEMI) with the surrounding radio communication environment. In general, from the waveforms of PEMI waves received by an antenna array, the source position can be located or the direction of arrival (DOA) of the EM waves can be estimated by applying TDOA-based methods. However, owing to noises and multipath waves that occur at the metal surfaces of electric power equipment, the estimation accuracy of the TDOA may decrease, and the location accuracy will be degraded. To improve the accuracy of TDOA estimation, we propose a new TDOA estimation technique. In our developed locating system, PEMI waves are received by a four-antenna-square array and the DOA is estimated from the TDOA, which is estimated using the generalized crosscorrelation phase transform method in combination with the proposed technique. A PEMI source is ultimately located by aiming a charge-coupled device camera, installed at the center of the antenna array, at the estimated DOA. The estimation accuracy of the locating system is evaluated through experimental measurements. The results show that the developed locating system can locate the position of a PEMI source existing within about 30 m from the system with high accuracy.Index Terms-Direction of arrival (DOA), localization, pulsed electromagnetic (EM) interference (PEMI), spark discharge, time difference of arrival (TDOA). 0018-9375

No abstract

No abstract

No abstract

No abstract

Hum Noise performance of 6 , 8, 10 conductor bundles (subconductor diameter:3.84cm) for 1,000kV transmission lines were measured at the Akagi ' test site and the results were compared with cage data. In general, Hum Noise levels calculated with cage data were higher than the long-term test results.It was revealed that the differences between calculated and measured levels were formulated with the maximum surface gradient. Based on this relationship a new prediction method for Hum Noise near ac transmission lines was proposed.

No abstract