Local discharge on-line detection method and device of high-voltage cross-linking polythene cable system

Abstract

The invention relates to local discharge on-line detection method and device of a high-voltage cross-linking polythene cable system. The device comprises a local discharge signal sensor, a local discharge signal conditioning and acquiring unit and an industry control computer. Software anti-interference is carried out on local discharge signals, various kinds of interference and noise are suppressed, weak local discharge signals are extracted from strong interference and are displayed in a discharge capacity form, a three-dimensional spectrum containing discharge times, the discharge capacityand a discharge phase is formed, and data which are continuously monitored by an enclosure are written into a database for the convenience of history inquiry, so that the trend change of the dischargecapacity of each enclosure is grasped and technical data for determining the insulated state of the cable system is provided. The invention has the advantages that: according to the on-site requirements, the method and the device can carry out wide band high-speed local discharge detection on an electrified cable system through the software-hardware combined anti-interference scheme, effectivelymonitor the insulated conditions of cable equipment, prevent catastrophic failures and provide scientific basis for state maintenance of a cable system.

Description

technical field [0001] The invention relates to an on-line partial discharge detection method and device of a high-voltage cross-linked polyethylene cable system, belonging to the technical field of cable equipment detection. Background technique [0002] With the development of high-voltage and ultra-high-voltage power cables, cross-linked polyethylene (XLPE) power cables are widely used in power systems due to their reasonable technology and structure, excellent electrical performance, simple installation and laying, less operation and maintenance work, and safety and reliability. has been more and more widely used. As an important part of urban power supply and main grid, high-voltage and extra-high-voltage cable system has occupied a very important position in my country's urban power grid. How to realize the status detection of these cable equipment and ensure the safe and reliable operation of the cable equipment is a hot research topic at home and abroad. Partial di...

AI Technical Summary

Problems solved by technology

Various construction defects caused by poor construction technology of intermediate joints make the distribution of electric field in the joints uneven, resulting in partial discharge

Under power frequency voltage, partial discharge will cause the generation and expansion of electrical trees in the cable insulation, and accelerate the deterioration of the insulation, eventually leading to insulation breakdown

[0004] At present, there are many XLPE cable partial discharge on-line detection devices developed at home and abroad, but the on-site measurement results are far from ideal. The main reason is: due to the weak partial discharge signal and small amplitude, it is easily overwhelmed by external strong electromagnetic field interference and background noise. , but the anti-interference scheme adopted by the devices developed at home and abroad is not ideal, and it is easy to misjudge the external interference as a partial discharge signal, and the narrow-band filter used by most devices will cause the partial discharge signal waveform to be distorted. Both greatly reduce the sensitivity, accuracy and reliability of online detection

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