Apparatus for monitoring degradation of insulation of electrical installation.

摘要

According to the invention, there is provided an apparatus for monitoring degradation of insulation of an electrical installation that can constantly monitor its electric equipments and cables for degradation of insulation under hot-line conditions. Said apparatus comprises: a first sensor for detecting a progressive wave generated by a partial discharge taking place at a location where the insulation is degraded in the power transmission paths; a second sensor for detecting the phase of said generated progressive wave as well as external noise; a third sensor for detecting a reference signal for determining the direction of said progressive wave; and a measurement section for processing the signals from the first sensor, second sensor and third sensor; wherein said measurement section determines existence or non-existence of degraded insulation by comparing the phases of the signals from the first sensor and the third sensor when it detects a progressive wave generated at a location where degradation of insulation of an electric cable or an electric equipment is taking place, and it also determines if the signal from each of the second sensor represents an external noise or degraded insulation and detects the phase of degradation if degraded insulation is involved.