DEGRADATION DIAGNOSING METHOD FOR POWER CABLE AND ITS ACCESSORIES IN LIVE STATE

摘要

PURPOSE: To make diagnosis of deterioration of a power cable and its accessories with extremely high precision by irradiating them with a laser beam in the operating condition in which AC or DC is being impressed, thereby sensing displacement signals for the space charges produced in the insulation, and determining the space charge distribution. ;CONSTITUTION: Ordinary connection parts 1A, 1B, 1C are grounded through respective grounding leads AG, BG, CG. The shield layer of insulative conection parts 2C, 2A is connected by a cross-bond wire CA. A target 4 for laser beam irradiation is mounted on the armouring part of a power cable 3A and irradiated with a pressure wave generating laser beam 5a emitted from a laser beam generation part 5. The displacement potential current generated when the space charges vibrate are sensed, for example, by a current transformer 6 mounted on the cross-bond wire CA. The obtained signal is amplified by an amplifier 7, subjected to a certain computerized processing 8, and converted into signals to show the space charge distribution in the insulation, which enables measuring of the space charges, and the diagnosis of deterioration can be executed precisely.;COPYRIGHT: (C)1993,JPO&Japio