A method for on-line monitoring and early warning of relay protection DC operating circuit

Abstract

The invention provides an online monitoring and early warning method for a relay protection DC operating circuit. The DC operating circuit includes a closing circuit and a tripping circuit; the method includes the following steps: respectively building a closing circuit monitoring branch and a tripping circuit monitoring branch; closing Component selection and parameter setting in the circuit monitoring branch and tripping circuit monitoring branch; detect the current value flowing through the closing / tripping circuit monitoring branch, and compare it with the closing / tripping circuit disconnection alarm current value to determine whether the closing / tripping circuit is There is a disconnection. The present invention builds the closing / tripping circuit monitoring branch, monitors the current value flowing through the closing / tripping circuit monitoring branch online, and judges whether there is a disconnection problem in the circuit according to the magnitude of the monitoring current, thereby realizing the integrity of the tripping and closing circuit Monitoring; this method can not only realize the full working condition monitoring of the integrity of the DC operating circuit, but also will not affect the normal operation of the system.

Description

technical field [0001] The invention relates to an early warning method, in particular to an on-line monitoring and early warning method for a relay protection DC operating circuit. Background technique [0002] Relay protection hardware defects are one of the main reasons for hidden faults, and incorrect protection actions caused by defects in the DC operating circuit account for a relatively high proportion. Therefore, effective monitoring and early warning of the DC operating circuit is the key to preventing hidden faults. , An important means to reduce the protection of incorrect actions. Poor contact of the DC operating circuit and disconnection of the circuit are important reasons for incorrect action of the protection. Conventional methods of direct monitoring of traffic light circuits or indirect monitoring of signal circuits connected in series with normally closed contacts of position relays all belong to non-full working condition monitoring. After closing (tripp...

AI Technical Summary

Problems solved by technology

The document "Design and Implementation of Circuit Breaker Operation Circuit with Trip Circuit Monitoring" points out a trip circuit disconnection monitoring scheme connected in series with high internal resistance relays, but the closing circuit in this scheme is still a non-full working condition monitoring

At the same time, the concept of intelligent operation box has also been proposed, but the use of intelligent operation box in conventional substations not only increases the complexity of the system but is also uneconomical

At present, there is no mature means to realize the comprehensive and effective monitoring of the DC operation circuit

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