Control circuit with self-checking function

Abstract

The invention provides a control circuit with a self-checking function. The control circuit comprises a circuit breaker connected with an operation power supply, a current maintaining circuit, a first monitoring circuit and a second monitoring circuit, wherein the circuit breaker comprises an internal coil and an internal contact connected with the internal coil; the current maintaining circuit is connected between the operation power supply and the internal contact of the circuit breaker in series and provides the internal coil with current in the operation process of the internal coil; the first monitoring circuit is connected with a detection contact of a relay in parallel and senses the operation correctness of the detection contact of the relay; and the second monitoring circuit is connected between the operation power supply and the internal contact of the circuit breaker in series and senses the electrical integrity of the control circuit of the relay. According to the control circuit, the integrity and the correctness of an electric circuit can be simultaneously monitored, and state maintenance of the whole control circuit is achieved.

Description

[0001] This application claims the priority of the invention patent application "a control circuit with self-test function" with the application date of January 19, 2016 and the application number 201610035618.0. The entire content of this application is included in the scope of this application by reference Inside. technical field [0002] The application relates to the field of industrial control, in particular to a control loop with self-checking function. Background technique [0003] Whether the various loop connections in the substation are normal or not affects whether the substation can work safely and reliably, and is an important issue in the operation of the substation. Under normal circumstances, the electrical equipment of the power system is inspected or overhauled (maintenance, debugging, test) according to the specified maintenance period, and the cycle is fixed for one year or several years, which is commonly referred to as regular maintenance. [0004] Wit...

AI Technical Summary

Problems solved by technology

[0014] The control circuits of the above two methods can monitor whether the tripping circuit or the closing circuit is intact, but if the contact J1 of the relay tripping and the contact J2 of closing are abnormal, such as failure to operate or contact adhesion, it will cause the circuit to malfunction. Serious consequences of action or protection refusal to trip and close

Severe accidents often occur on the substation site due to abnormal relays, but the control loops of the above two methods cannot realize the monitoring of the action contacts J1 and J2

Therefore, the existing control circuit can only monitor the integrity of the tripping and closing circuit, but cannot monitor the correctness of the tripping and closing circuit, that is, it cannot guarantee that the entire circuit can operate correctly when needed, and cannot realize the state-of-the-art maintenance of the entire control circuit

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