Diagnostic system and diagnostic method of contact state of high-voltage circuit breaker

Abstract

The present invention relates to a diagnostic system and diagnostic method of a contact state of a high-voltage circuit breaker. The diagnostic system is formed by connecting a contact dynamic resistance measurement device and a contact state diagnostic device. The method comprises: the contact dynamic resistance measurement device is configured to obtain a dynamic resistance-stroke curve of the opening process of the breaker contact; the contact state diagnostic device is configured to calculate the correlation coefficient of the dynamic resistance-stroke curve of the opening process and an initial curve; and the contact state diagnostic device is configured to compare the correlation coefficient of the curves and the area of the contact portion of the arc contact with a standard value to obtain the diagnosis result of the contact state. According to the invention, the correlation coefficient of a dynamic resistance curve and the area of the contact portion of an arc contact are taken as characteristic quantities and are used for comparing with a standard value to obtain a contact state so as to facilitate effective diagnosis of the inner condition of an arc extinguish chamber, and therefore the diagnostic system and diagnostic method of a contact state of a high-voltage circuit breaker diagnose are high in accuracy, fast in detection speed, convenient and rapid, and do not need to disassemble the arc extinguish chamber, etc.

Description

technical field [0001] The invention belongs to the technical field of high-voltage circuit breaker fault detection, in particular to a high-voltage circuit breaker contact state diagnosis system and method. Background technique [0002] High-voltage circuit breakers are important protection and control equipment in the power grid, and their reliability directly affects the safe and stable operation of the entire power system. Every time the circuit breaker breaks the fault current, the arc will ablate the contacts to a certain extent. When the contacts are ablated to a certain extent, it may lead to a decrease in the breaking and insulation capabilities of the high-voltage circuit breaker, burying hidden dangers for the safety of the power grid. . At present, the test items for evaluating the state of the circuit breaker contacts are mainly to measure the main circuit resistance, that is, the static contact resistance. However, due to the sealed structure of the arc exting...

AI Technical Summary

Problems solved by technology

Every time the circuit breaker breaks the fault current, the arc will ablate the contacts to a certain extent. When the contacts are ablated to a certain extent, it may lead to a decrease in the breaking and insulation capabilities of the high-voltage circuit breaker, burying hidden dangers for the safety of the power grid.

At present, the test items for evaluating the state of the circuit breaker contacts are mainly to measure the main circuit resistance, that is, the static contact resistance. However, due to the sealed structure of the arc extinguishing chamber of the high-voltage circuit breaker, it is difficult to effectively evaluate the state of the contacts by general methods, and Its contact system is composed of main contacts and arc contacts in parallel. The main circuit resistance measurement can only reflect the state of the main contacts, but cannot reflect the contact condition of the arc contacts. This measurement method is difficult to ensure the accuracy of the evaluation of the contact state. sex

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