A method, system and medium for detecting switching timing of an on-load tap changer

Abstract

The invention discloses a switching timing detection method, system and medium of an on-load tap changer. The method includes: the invention selectively disconnects the single / double-side main After the electrical connection line of the on-off contact is switched, the voltage signal at both ends of the on-load tap-changer is collected during the switching process; the characteristic points of the corresponding voltage signal are extracted, so that the on-off timing of all contacts can be measured; at DC5A load current Under normal conditions, the on-load tap-changer switching is normally performed, and the voltage signal during the switching process is collected; the characteristic parameters of the corresponding voltage signal are extracted, and the electrical connection of the single / double-side main on-off contact and the single / double-side transition contact is determined. point, electrical breaking point, mechanical contact point, mechanical breaking point and corresponding arcing interval. The method provided by the invention can improve the completeness and accuracy of the switching timing detection of the on-load tap changer contacts.

Description

technical field [0001] The invention relates to the technical field of transformer on-load tap changers, in particular to a method and system for detecting the switching sequence of on-load tap changers. Background technique [0002] When the power system is running, due to the change of the load, the bus voltage also changes, and a voltage deviation occurs between the actual voltage of the bus and the rated voltage. The power system has strict requirements on the degree of voltage deviation, therefore, a technology for regulating the bus voltage is required. On-load tap-changers can realize uninterrupted voltage regulation of power systems by switching the taps of power transformers under load conditions, and have been more and more widely used. [0003] In recent years, power outage accidents caused by the electrical contact fault of the on-load tap-changer have been reported repeatedly, and mechanical and electrical faults are the main factors leading to the failure of t...

AI Technical Summary

Problems solved by technology

[0004] During the switching process of the on-load tap-changer, it involves the mechanical wear and electrical erosion of the contacts, which may lead to poor contact between the contacts and an increase in contact resistance, and even cause changes in the switching sequence of the contacts, seriously reducing the on-load tap-changer. operational reliability

[0005] However, there are limited methods for detecting the switching state of the on-load tap-changer

The traditional mechanical state detection method uses vibration signals to realize the "stethoscope" inspection of the mechanical state of the on-load tap-changer. It is one of the widely used monitoring and diagnosis methods at present. Electrical performance parameters of contacts

The traditional DC test is mostly carried out under the condition of DC1A current load. Although the electrical signal of the on-load tap-changer can be detected, the arcing condition cannot be achieved, which is far from the actual operating condition of the on-load tap-changer, and It can only detect the on-off state of some contacts, and cannot detect whether there is a defect in the on-off state of all contacts

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