Acousto-optic combined detection method and system for partial discharging of a high-voltage cable

Abstract

The invention discloses an acousto-optic combined detection method and system for partial discharging of a high-voltage cable. On the basis of fusion of ultrasonic and ultraviolet sensing type non-electrical detection technologies, a partial discharge detection mode of non-fixed high-voltage cable inspection in a complex and strong electromagnetic interference environment is performed by using low-cost portable ultrasonic and ultraviolet sensors to realize synchronous and efficient collection of ultraviolet light and ultrasonic signals of partial discharge of the high-voltage cable; and then multi-analytical-domain partial-distribution information mining and fusion processing of ultrasonic and ultraviolet light pulses is performed, so that the partial discharge detection information is enriched substantially. Partial discharge information that can not be provided by the single technology is provided; the accurate identification and determination of the partial discharge type, cable fault diagnosis, and health status assessment are performed; and real-time storage and analysis of two paths of partial discharge information as well as display and alarm interaction and the like on the main control module are realized.

Description

technical field [0001] The invention belongs to the technical field of partial discharge detection in electric power systems, in particular to an acousto-optic joint detection method and system for high-voltage cable partial discharge. Background technique [0002] High-voltage cable faults are directly related to the safety and stability of the entire power system. At the high-voltage cables and their terminals and intermediate joints, since the electric field strength of each part is often unequal, partial discharges are prone to occur, which will cause damage to the insulating medium, and the degree of damage is related to the magnitude of the discharge and the discharge time. If such faults are not dealt with in time, it may lead to the final breakdown and failure of insulation, and even damage to electrical equipment. In order to prevent such accidents, on-line detection of high-voltage cable partial discharge is very important without affecting normal power transmissi...

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Problems solved by technology

[0007] It can be seen from the above table that the current detection method is mainly based on a single technology type detection, and the instruments for multi-parameter monitoring of partial discharge are pulse current method and ultrasonic detection method, UHF method and pulse current method, UHF method and ultrasonic detection method Combination of methods, etc., all of which are based on joint detection of electrical methods, it is difficult to extract partial discharge signals in a strong electromagnetic interference environment

The ultraviolet and ultrasonic joint detection system proposed by CN102495343B adopts an array sensing structure, and the ultraviolet sensor adopts a spectral imaging method, and the cost is relatively high; the overall structure of the partial discharge detection system for long-distance high-voltage cables is complicated, and it is suitable for distributed fixed-point installation and detection, which is inconvenient Portable inspection; and the extraction of partial discharge information is mainly based on the energy spectrum distribution and entropy signal obtained after wavelet packet decomposition of ultrasonic and ultraviolet spectral signals. The extracted information is limited and the function is relatively single. It only involves partial discharge judgment and simple type identification. It does not involve important functions such as cable fault diagnosis and health status assessment; the combined detection method of ultraviolet, ultrasonic and ultra-high frequency proposed by CN207424175U is mainly for fixed-point detection of switch cabinet partial discharge, which is not suitable for portable inspection of high-voltage cables, and uses hardware devices Mainly, no specific information mining and fusion methods are involved

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