Bush monitor and its supervisory manner

摘要

PROBLEM TO BE SOLVED: To measure the deterioration and the remaining life of a non- porcelaneous bushing correctly, without cutting off power supply or requiring power by measuring a leakage current flowing throgh the non-porcelaneous bushing and a partial discharge pulse at the same time. ;SOLUTION: Since the breakdown voltage of a non-porcelaneous bushing decreases as its leak current increases, a mutual relation exist between the increment of the leakage current and the decrement of the breakdown voltage. In addition, because the leakage current varies in depending on local time and weather conditions, more correct decision can be performed by considering deterioration caused by heat and corona discharge due to the leak current flowing. The bushing and GIS are insulated from each other by an insulating flange 4, and the leak current flowing through the bushing 1 is measured by a current transformer 14 and the pulse due to partial discharge is measured by a pulse detector 10. By processing these two signals through an arithmetic processing unit 13, the deterioration and the remaining life are determined from the peak leakage current, and frequency in the generation and the duration of the pulse.;COPYRIGHT: (C)1999,JPO