XLPE cable sheath current on-line monitoring and fault diagnosis system

Abstract

The invention discloses an XLPE cable sheath current on-line monitoring and fault diagnosis system which is composed of a current sensor and an on-line monitoring device. The current sensor is installed on a grounding wire of a cable cross interconnection box to be detected, the current sensor is connected with the online monitoring device through a high-shielding coaxial cable, and the online monitoring device can upload a monitoring result to an upper system platform in a network port or optical port mode. Different on-line monitoring devices can run from a looped network, and the device has an edge calculation function, is internally provided with a fault diagnosis algorithm, and can realize information processing, fault diagnosis, alarm and the like on site. According to the method, whether the insulation of the XLPE cable in operation is broken down or not can be accurately and effectively judged, the cable sheath current is used as a characteristic signal, signal characteristic extraction and fault identification are carried out, and a corresponding criterion is given to represent the insulation performance of the power cable.

Description

technical field [0001] The invention relates to a high-voltage cable online monitoring system, in particular to an XLPE cable sheath current online monitoring and fault diagnosis system. Background technique [0002] For cross-linked polyethylene (XLPE) power cables with a voltage level of 66kV and above in my country's power grid system, due to factors such as production quality, external force damage, and insulation aging, it is easy to cause insulation damage or line failure. At present, the detection of XLPE cable status mainly uses the method of regular inspection and power failure preventive test. This method belongs to offline monitoring, and there are problems such as inaccurate test model and introduction of test damage risk. XLPE cables with higher voltage levels generally adopt the live detection method. The detection results of this method conform to the actual operation of the cable, but there are problems such as high operation and maintenance costs and inabili...

AI Technical Summary

Problems solved by technology

At present, the detection of XLPE cable status mainly uses the method of regular inspection and power failure preventive test. This method belongs to offline monitoring, and there are problems such as inaccurate test model and introduction of test damage risk.

XLPE cables with higher voltage levels generally adopt the live detection method. The detection results of this method are in line with the actual operation of the cable, but there are problems such as high operation and maintenance costs and inability to continuously monitor

The existing on-line cable monitoring methods include fiber optic temperature measurement, sheath current, partial discharge and other monitoring methods. Compared with the existing on-line monitoring methods, the on-line monitoring of sheath current is a method with simple operation and strong engineering applicability. However, the current fault diagnosis of this method is generally implemented in the monitoring host, which increases the cost of system construction and the difficulty of accessing the comprehensive monitoring system of the substation; and the diagnosis model is relatively simple, and the accuracy of cable operation status identification needs to be further improved

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