Circuit breaker opening and closing loop monitoring system and method

Abstract

The invention discloses a circuit breaker opening and closing loop monitoring system and method, relates to the technical field of electric power operation and maintenance, and mainly aims to solve the problem of low monitoring accuracy of a circuit breaker opening and closing loop. The device mainly comprises a circuit breaker auxiliary contact and a circuit breaker opening and closing loop monitor, the circuit breaker opening and closing loop monitor comprises a switching value input circuit, a first voltage monitoring circuit, a second voltage monitoring circuit, a central control module and an alarm circuit, the state of the auxiliary contact is collected, and the opening and closing state of the circuit breaker is determined according to the state of the auxiliary contact. And collecting a first voltage value at two ends of a normally closed contact of the circuit breaker and a second voltage value at two ends of a normally open contact of the circuit breaker, and monitoring a corresponding loop according to the opening and closing states of the circuit breaker and a comparison result of the first voltage value or the second voltage value and a preset voltage threshold value. The circuit breaker is used for monitoring the integrity of a closing loop in a closing state of the circuit breaker and the integrity of an opening loop in an opening state of the circuit breaker, and giving an alarm under the condition that the loops are broken.

Description

Technical Field

[0001] The present invention relates to the technical field of power operation and maintenance, and particularly to a monitoring system and method for the closing and opening circuits of a circuit breaker. Background Art

[0002] A circuit breaker is an indispensable protection and control device in the power system, and is an important device to ensure the safe and stable operation of the power system and protect the safety of equipment and personnel. The closing and opening circuits of the circuit breaker, as the control circuits responsible for controlling the closing and opening operations of the circuit breaker, are important components in the power system. By monitoring the closing and opening circuits of the circuit breaker, the closing and opening states of the circuit breaker can be monitored in real time to ensure that it can operate correctly when needed, and in the case of misoperation or failure of the circuit breaker, early warnings can be given in time to avoid potential safety hazards and prevent the expansion of accidents.

[0003] Currently, the existing methods for monitoring the closing and opening circuits of a circuit breaker mainly adopt the method of connecting the normally closed contacts of the trip position relay and the closing position relay in series. However, this method can only monitor the integrity of the opening circuit in the closing state and the closing circuit in the opening state of the circuit breaker, and the integrity of the closing and opening circuits in other states cannot be monitored, so it is impossible to comprehensively monitor the integrity of the closing and opening circuits of the circuit breaker in various states, resulting in relatively low monitoring accuracy of the closing and opening circuits of the circuit breaker. Summary of the Invention

[0004] In view of this, the present invention provides a monitoring system for the closing and opening circuits of a circuit breaker, and the main purpose is to solve the problem of relatively low monitoring accuracy of the existing closing and opening circuits of the circuit breaker.

[0005] According to one aspect of the present invention, a monitoring system for the closing and opening circuits of a circuit breaker is provided, including: breaker auxiliary contacts and a monitoring instrument for the closing and opening circuits of the circuit breaker, and the monitoring instrument for the closing and opening circuits of the circuit breaker includes a digital input circuit, a first voltage monitoring circuit, a second voltage monitoring circuit, a central control module and an alarm circuit; The digital input circuit is connected to the breaker auxiliary contacts and is used for collecting the states of the auxiliary contacts, wherein the states of the auxiliary contacts are synchronously switched along with the opening and closing states of the breaker; Two input contacts of the first voltage monitoring circuit are respectively connected to both ends of the normally closed contact of the breaker in the closing circuit of the breaker, and are used for collecting the first voltage value at both ends of the normally closed contact of the breaker; Two input contacts of the second voltage monitoring circuit are respectively connected to both ends of the normally open contact of the breaker in the opening circuit of the breaker, and are used for collecting the second voltage value at both ends of the normally open contact of the breaker; The central control module is used to obtain a preset voltage threshold and the status of the auxiliary contact. When it is determined that the circuit breaker is in the closed state based on the status of the auxiliary contact and the first voltage value is less than the preset voltage threshold, a closing loop alarm signal in the closed state is output through the alarm circuit. When it is determined that the circuit breaker is in the open state based on the status of the auxiliary contact and the second voltage value is less than the preset voltage threshold, a tripping loop alarm signal in the open state is output through the alarm circuit; The alarm circuit is used to output an alarm signal under the control of the central control module; Wherein, both the first voltage monitoring circuit and the second voltage monitoring circuit include a high-impedance resistor voltage dividing circuit to ensure that the closing and tripping loops are not affected during voltage acquisition.

[0006] Further, when the circuit breaker closing and tripping loops are connected to the anti-pumping loop of the circuit breaker mechanism, the circuit breaker closing loop includes a newly added normally closed contact of the circuit breaker and a normally closed contact of the anti-pumping relay connected in series to inhibit the mutual activation of the tripping position relay and the anti-pumping relay. The system includes a voltage dividing resistor; The voltage dividing resistor is used to replace the normally closed contact of the circuit breaker and the normally closed contact of the anti-pumping relay connected in series in the circuit breaker closing loop before the first voltage monitoring circuit collects the first voltage value, so that the voltage division of the tripping position relay and the anti-pumping relay is less than their respective starting voltages, and the first voltage monitoring circuit can be conducted. Wherein, the newly added normally closed contact of the circuit breaker and the normally closed contact of the anti-pumping relay in the circuit breaker closing loop are connected in series to inhibit the mutual activation of the tripping position relay and the anti-pumping relay.

[0007] Further, the digital input circuit includes a first digital input circuit and a second digital input circuit; The first digital input circuit is used to collect the status of the normally closed auxiliary contact of the circuit breaker; The second digital input circuit is used to collect the status of the normally open auxiliary contact of the circuit breaker; The central control module is further used to determine that the circuit breaker is in the closed state when the status of the normally closed auxiliary contact of the circuit breaker is open; and determine that the circuit breaker is in the open state when the status of the normally open auxiliary contact of the circuit breaker is open.

[0008] Further, the system further includes a control loop open circuit, and the alarm circuit includes a first alarm circuit and a second alarm circuit; The control loop disconnection circuit includes normally-closed contacts of a closing position relay and normally-closed contacts of a tripping position relay connected in series. When both the normally-closed contacts of the closing position relay and the normally-closed contacts of the tripping position relay are closed, the control loop disconnection circuit outputs an alarm signal for the tripping circuit in the closing state or an alarm signal for the closing circuit in the tripping state according to the closing and tripping states of the circuit breaker. The first alarm circuit is used to output an alarm signal for the closing circuit, and the second alarm circuit is used to output an alarm signal for the tripping circuit. Among them, the output contacts of the first alarm circuit and the second alarm circuit are connected to the output end of the control loop disconnection circuit to output the alarm signal in parallel with the control loop disconnection circuit. The central control module is further configured to suppress the output of the first alarm circuit when the state of the normally-closed auxiliary contact of the circuit breaker is closed, so as to output an alarm signal for the closing circuit in the tripping state through the control loop disconnection circuit; when the state of the normally-open auxiliary contact of the circuit breaker is closed, suppress the output of the second alarm circuit, so as to output an alarm signal for the tripping circuit in the closing state through the control loop disconnection circuit.

[0009] Further, the first voltage monitoring circuit includes a first sampling circuit, a first amplifying circuit and a first analog-to-digital conversion circuit, and the second voltage detection circuit includes a second sampling circuit, a second amplifying circuit and a second analog-to-digital conversion circuit; The first sampling circuit is used to collect a first voltage analog signal across the normally-closed contacts of the circuit breaker in the closing loop of the circuit breaker; The first amplifying circuit is used to amplify the first voltage analog signal to obtain an amplified first voltage analog signal; The first analog-to-digital conversion circuit is used to convert the amplified first voltage analog signal into a digital signal to obtain a first voltage value; The second sampling circuit is used to collect a second voltage analog signal across the normally-open contacts of the circuit breaker in the tripping loop of the circuit breaker; The second amplifying circuit is used to amplify the second voltage analog signal to obtain an amplified second voltage analog signal; The second analog-to-digital conversion circuit is used to convert the amplified second voltage analog signal into a digital signal to obtain a second voltage value.

[0010] According to another aspect of the present invention, a method for monitoring the closing and tripping loops of a circuit breaker is provided, including: Obtain a preset voltage threshold and the state of the auxiliary contacts collected by the switch input circuit, where the switch input circuit is connected to the auxiliary contacts of the circuit breaker, and the state of the auxiliary contacts is synchronously switched with the opening and closing states of the circuit breaker; Collect the first voltage value across the normally-closed contact of the circuit breaker in the closing circuit of the circuit breaker through two input contacts of the first voltage monitoring circuit, where the two input contacts of the first voltage monitoring circuit are respectively connected across the normally-closed contact of the circuit breaker in the closing circuit of the circuit breaker; Collect the second voltage value across the normally-open contact of the circuit breaker in the opening circuit of the circuit breaker through two input contacts of the second voltage monitoring circuit, where the two input contacts of the second voltage monitoring circuit are respectively connected across the normally-open contact of the circuit breaker in the opening circuit of the circuit breaker; When it is determined that the circuit breaker is in the closing state based on the status of the auxiliary contact and the first voltage value is less than the preset voltage threshold, control the alarm circuit to output an alarm signal for the closing circuit in the closing state; When it is determined that the circuit breaker is in the opening state based on the status of the auxiliary contact and the second voltage value is less than the preset voltage threshold, control the alarm circuit to output an alarm signal for the opening circuit in the opening state; Wherein, both the first voltage monitoring circuit and the second voltage monitoring circuit include a high-impedance resistor voltage-dividing circuit to not affect the operation of the closing and opening circuits during voltage acquisition.

[0011] Further, when the anti-trip circuit of the circuit breaker mechanism is connected to the closing and opening circuits of the circuit breaker, the closing circuit of the circuit breaker includes a newly added normally-closed contact of the circuit breaker and a normally-closed contact of the anti-trip relay connected in series to inhibit the mutual activation of the opening position relay and the anti-trip relay; Before collecting the first voltage value across the normally-closed contact of the circuit breaker in the closing circuit of the circuit breaker through two input contacts of the first voltage monitoring circuit, the method further includes: Replace the newly added normally-closed contact of the circuit breaker and the normally-closed contact of the anti-trip relay connected in series in the closing circuit of the circuit breaker with a voltage-dividing resistor so that the voltage division of the opening position relay and the anti-trip relay is less than their respective starting voltages, and the first voltage monitoring circuit can be turned on.

[0012] Further, the digital input circuit includes a first digital input circuit and a second digital input circuit, and the status of the auxiliary contact includes the status of the normally-closed auxiliary contact of the circuit breaker and the status of the normally-closed auxiliary contact of the circuit breaker; determining the closing and opening states of the circuit breaker based on the status of the auxiliary contact includes: Collect the status of the normally-closed auxiliary contact of the circuit breaker through the first digital input circuit, and when the status of the normally-closed auxiliary contact of the circuit breaker is open, determine that the circuit breaker is in the closing state; Collect the status of the normally-open auxiliary contact of the circuit breaker through the second digital input circuit, and when the status of the normally-open auxiliary contact of the circuit breaker is open, determine that the circuit breaker is in the opening state.

[0013] Further, the alarm circuit includes a first alarm circuit and a second alarm circuit. Among them, the output contacts of the first alarm circuit and the second alarm circuit are connected to the output end of the control loop disconnection circuit to output an alarm signal in parallel with the control loop disconnection circuit. The control loop disconnection circuit includes normally closed contacts of a closing position relay and normally closed contacts of a tripping position relay connected in series. The control loop disconnection circuit outputs an alarm signal for the tripping circuit in the closing state or an alarm signal for the closing circuit in the tripping state according to the state of the circuit breaker when both the normally closed contacts of the closing position relay and the normally closed contacts of the tripping position relay are closed; When the normally closed auxiliary contact of the circuit breaker is in the closed state, the output of the first alarm circuit is suppressed to output an alarm signal for the closing circuit in the tripping state through the control loop disconnection circuit; When the normally open auxiliary contact of the circuit breaker is in the closed state, the output of the second alarm circuit is suppressed to output an alarm signal for the tripping circuit in the closing state through the control loop disconnection circuit.

[0014] Further, the first voltage monitoring circuit includes a first sampling circuit, a first amplifying circuit and a first analog-to-digital conversion circuit, and the second voltage detection circuit includes a second sampling circuit, a second amplifying circuit and a second analog-to-digital conversion circuit; The acquisition of the first voltage value across the normally closed contacts of the circuit breaker in the closing loop of the circuit breaker through the two input contacts of the first voltage monitoring circuit includes: Collecting the first voltage analog signal across the normally closed contacts of the circuit breaker in the closing loop of the circuit breaker through the first sampling circuit, amplifying the first voltage analog signal through the first amplifying circuit to obtain the amplified first voltage analog signal, and converting the amplified first voltage analog signal into a digital signal through the first analog-to-digital conversion circuit to obtain the first voltage value; The acquisition of the second voltage value across the normally open contacts of the circuit breaker in the tripping loop of the circuit breaker through the two input contacts of the second voltage monitoring circuit includes: Collecting the second voltage analog signal across the normally open contacts of the circuit breaker in the tripping loop of the circuit breaker through the second sampling circuit, amplifying the second voltage analog signal through the second amplifying circuit to obtain the amplified second voltage analog signal, and converting the amplified second voltage analog signal into a digital signal through the second analog-to-digital conversion circuit to obtain the second voltage value.

[0015] By means of the above technical solutions, the technical solutions provided by the embodiments of the present invention have at least the following advantages: The present invention provides a monitoring system and method for the closing and opening circuits of a circuit breaker. In the embodiments of the present invention, a switch input circuit is connected to the auxiliary contacts of the circuit breaker, and the status of the auxiliary contacts is collected through the switch input circuit; two input contacts of the first voltage monitoring circuit are respectively connected to both ends of the normally closed contact of the circuit breaker in the closing circuit of the circuit breaker, and the first voltage value at both ends of the normally closed contact of the circuit breaker is collected through the first voltage monitoring circuit; two input contacts of the second voltage monitoring circuit are respectively connected to both ends of the normally open contact of the circuit breaker in the opening circuit of the circuit breaker, and the second voltage value at both ends of the normally open contact of the circuit breaker is collected through the second voltage monitoring circuit; through the central control module, a preset voltage threshold and the status of the auxiliary contacts are obtained. When it is determined according to the status of the auxiliary contacts that the circuit breaker is in the closing state and the first voltage value is less than the preset voltage threshold, an alarm signal for the closing circuit in the closing state is output through the alarm circuit. When it is determined according to the status of the auxiliary contacts that the circuit breaker is in the opening state and the second voltage value is less than the preset voltage threshold, an alarm signal for the opening circuit in the opening state is output through the alarm circuit; through the alarm circuit, under the control of the central control module, an alarm signal is output, realizing the monitoring of the closing circuit in the closing state of the circuit breaker and the opening circuit in the opening state of the circuit breaker, greatly increasing the comprehensiveness of the monitoring of the closing and opening circuits of the circuit breaker, making up for the shortcomings of the existing monitoring means, and thus improving the accuracy of the monitoring of the closing and opening circuits of the circuit breaker.

[0016] The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are given below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. And throughout the drawings, the same reference numerals are used to represent the same components. In the drawings: Figure 1 shows a block diagram of a monitoring system for the closing and opening circuits of a circuit breaker provided by an embodiment of the present invention; Figure 2 shows a schematic diagram of the circuit connection relationship of the closing and opening circuits provided by an embodiment of the present invention; Figure 3 shows a schematic diagram of the closing circuit connection of a monitoring instrument for the closing and opening circuits of a circuit breaker provided by an embodiment of the present invention; Figure 4 shows a schematic diagram of the opening circuit connection of a monitoring instrument for the closing and opening circuits of a circuit breaker provided by an embodiment of the present invention; Figure 5Shows the closing circuit of an anti - bounce loop of an access breaker mechanism provided by an embodiment of the present invention; Figure 6 Shows the closing circuit of an anti - bounce loop of an access breaker mechanism after being transformed based on voltage - dividing resistors provided by an embodiment of the present invention; Figure 7 Shows the block diagram of the composition of a monitor for the closing and opening circuits of an access breaker provided by an embodiment of the present invention; Figure 8 Shows the schematic diagram of a prototype of a monitor for the closing and opening circuits of an access breaker provided by an embodiment of the present invention. Specific embodiments

[0018] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0019] Aiming at the problem of low monitoring accuracy of the existing closing and opening circuits of a breaker. Embodiments of the present invention provide a monitoring system for the closing and opening circuits of a breaker, as Figure 1 shown. The system includes: A breaker auxiliary contact 100 and a monitor 200 for the closing and opening circuits of the breaker. The monitor 200 for the closing and opening circuits of the breaker includes a digital input circuit 210, a first voltage monitoring circuit 220, a second voltage monitoring circuit 230, a central control module 240, and an alarm circuit 250.

[0020] Among them, the digital input circuit 210 is connected to the auxiliary contact 100 of the circuit breaker, and the state of the auxiliary contact is collected through the digital input circuit 210; two input contacts of the first voltage monitoring circuit 220 are respectively connected to both ends of the normally closed contact of the circuit breaker in the closing loop of the circuit breaker, and the first voltage value at both ends of the normally closed contact of the circuit breaker is collected through the first voltage monitoring circuit 220; two input contacts of the second voltage monitoring circuit 230 are respectively connected to both ends of the normally open contact of the circuit breaker in the opening loop of the circuit breaker, and the second voltage value at both ends of the normally open contact of the circuit breaker is collected through the second voltage monitoring circuit 230; through the central control module 240, a preset voltage threshold and the state of the auxiliary contact are obtained. When it is determined that the circuit breaker is in the closing state based on the state of the auxiliary contact and the first voltage value is less than the preset voltage threshold, a closing loop alarm signal in the closing state is output through the alarm circuit 250. When it is determined that the circuit breaker is in the opening state based on the state of the auxiliary contact and the second voltage value is less than the preset voltage threshold, an opening loop alarm signal in the opening state is output through the alarm circuit 250; under the control of the central control module 230, an alarm signal is output through the alarm circuit 250.

[0021] The closing and opening loops of the circuit breaker, as the loops for controlling the closing and opening of the circuit breaker, include two loops: the closing loop and the opening loop. As Figure 2 shown, for the existing closing and opening loops, both ends of the closing loop and the opening loop are connected in parallel and powered by ±220V. The closing loop includes a circuit breaker manual control switch, a normally closed contact of the circuit breaker, and a closing coil connected in series; the opening loop includes a circuit breaker manual control switch, a normally open contact of the circuit breaker, and an opening coil connected in series.

[0022] In the embodiment of the present invention, in order to monitor whether the lines of the closing and opening loops of the circuit breaker are intact, the first voltage monitoring circuit 220 of the circuit breaker closing and opening loop monitor 200 is connected to both ends of the normally closed contact of the circuit breaker in the closing loop to collect the first voltage value at both ends of the normally closed contact of the circuit breaker in the closing loop. The second voltage monitoring circuit 230 is connected to both ends of the normally open contact of the circuit breaker in the opening loop to collect the second voltage value at both ends of the normally open contact of the circuit breaker in the opening loop. As Figure 3Taking the schematic diagram of the closing circuit connection of the access breaker closing and opening circuit monitor as an example, the two input contacts of the first voltage monitoring circuit of the breaker closing and opening circuit monitor are respectively connected to the two contacts A and B of the normally closed contact of the breaker in the closing circuit. When the breaker is in the closed state, the normally closed contact of the breaker in the closing circuit is open. At this time, if the circuit is intact, there is a voltage difference of 220V between points A and B, that is, the first voltage value is 220V. If the voltage difference between points A and B disappears, that is, the first voltage value is less than the preset voltage threshold, it can be determined that the closing circuit is interrupted. Among them, the preset voltage threshold can be 0 or a voltage value close to 0, and can be customized according to actual needs. For the same reason, as Figure 4 the schematic diagram of the opening circuit connection of the access breaker closing and opening circuit monitor shown. In the opening circuit, when the breaker is in the open state, the normally open contact of the breaker in the opening circuit is open. At this time, if the circuit is intact, there is a voltage difference of 220V between points C and D, that is, the second voltage value is 220V. If the voltage difference between points C and D disappears, that is, the second voltage value is less than the preset voltage threshold, it can be determined that the opening circuit is interrupted. The above judgment process based on the comparison result of the preset voltage threshold and the first voltage value or the second voltage value, and the breaker closing and opening state is executed by the central control module 240, and when it is judged that the circuit is interrupted, an alarm signal is output through the alarm circuit. The alarm signal can notify the on-site operation and maintenance personnel in one or more ways of sound, light, and electricity, and the embodiments of the present invention do not make specific limitations.

[0023] Among them, the opening and closing state of the breaker is collected through the digital input circuit 210 of the breaker closing and opening circuit monitor 200. Taking the Figure 3 schematic diagram of the closing circuit connection shown as an example, the digital input circuit is connected to the auxiliary contact of the breaker to collect the connection state (auxiliary contact state) of the auxiliary contact of the breaker. Since the auxiliary contact state changes synchronously with the opening and closing state of the breaker, the opening and closing state of the current breaker can be judged according to the auxiliary contact state.

[0024] It should be noted that both the first voltage monitoring circuit and the second voltage monitoring circuit include a high-impedance resistor voltage dividing circuit. Specifically, the internal resistance of the resistor voltage dividing circuit is greater than 20M. Due to the high impedance of the first voltage monitoring circuit and the second voltage monitoring circuit, when connected in parallel with the normally open or normally closed contacts of the breaker, it will not divert the current in the opening or closing circuit and affect the normal operation of the circuit, that is, it does not affect the operation of the closing and opening circuits during the voltage acquisition process.

[0025] In an embodiment of the present invention, for further explanation and limitation, when the breaker closing and opening circuit is connected to the breaker mechanism anti-jump circuit, the system includes a voltage dividing resistor.

[0026] Among them, before the first voltage monitoring circuit collects the first voltage value through a voltage-dividing resistor, the normally-closed contact of the circuit breaker and the normally-closed contact of the anti-trip relay connected in series in the closing circuit of the circuit breaker are replaced, so that the voltage division of the regulating tripping position relay and the anti-trip relay is less than their respective starting voltages, and the first voltage monitoring circuit can be conducted.

[0027] An in-mechanism anti-trip mechanism is configured inside the circuit breaker to be monitored. That is, when the closing and tripping circuits of the circuit breaker are connected to the in-mechanism anti-trip circuit of the circuit breaker, the closing circuit of the circuit breaker adds a circuit breaker contact, an anti-trip relay, and a normally-open (normally-closed) contact of the anti-trip relay. This makes the closing circuit of the circuit breaker add a newly added normally-closed contact of the circuit breaker and a normally-closed contact of the anti-trip relay connected in series to inhibit the mutual startup of the tripping position relay and the anti-trip relay. As Figure 5 shown, the anti-trip relay, the normally-closed contact of the anti-trip relay, and the normally-open contact of the anti-trip relay are added to the closing circuit, and a new break point is added, that is, a newly added normally-closed contact of the circuit breaker. When the circuit breaker is in the closing state, the newly added normally-closed contact of the circuit breaker is in the open state. At this time, the circuit is in a non-conducted state, and the voltage between points A and B is 0, which does not meet the access conditions of the circuit breaker closing and tripping circuit monitor.

[0028] In the embodiment of the present invention, the newly added normally-closed contact of the circuit breaker and the normally-closed contact of the anti-trip relay connected in series in the closing circuit are replaced with a voltage-dividing resistor. The closing circuit after the replacement of the voltage-dividing resistor is as Figure 6 shown. Among them, the voltage-dividing resistor is a high-impedance voltage-dividing resistor with a value above kilohms. By replacing the series circuit of the newly added normally-closed contact of the circuit breaker and the normally-closed contact of the anti-trip relay with a voltage-dividing resistor, the voltages at both ends of the tripping position relay and the anti-trip relay are reduced by voltage division, so that the voltages at both ends of the tripping position relay and the anti-trip relay are less than their corresponding starting voltages. At the same time, the conduction state of the closing circuit is ensured. Through the above transformation, the closing circuit meets the anti-trip requirement and conforms to the access conditions of the circuit breaker closing circuit monitor. Therefore, when the closing circuit of the circuit breaker is connected to the in-mechanism anti-trip circuit of the circuit breaker, both the anti-trip mechanism is ensured and the normal monitoring of the closing and tripping circuits of the circuit breaker by the circuit breaker closing and tripping circuit monitor is realized.

[0029] In an embodiment of the present invention, for further illustration and limitation, the switch quantity input circuit includes a first switch quantity input circuit and a second switch quantity input circuit.

[0030] Among them, the state of the normally-closed auxiliary contact of the circuit breaker is collected through the first switch quantity input circuit; the state of the normally-closed auxiliary contact of the circuit breaker is collected through the second switch quantity input circuit; through the central control module, when the state of the normally-closed auxiliary contact of the circuit breaker is open, it is determined that the circuit breaker is in the closing state; when the state of the normally-open auxiliary contact of the circuit breaker is open, it is determined that the circuit breaker is in the tripping state.

[0031] In the embodiment of the present invention, the circuit breaker closing and opening loop monitor provides two first digital input circuits and a second digital input circuit, which can respectively form a circuit combination with the first voltage monitoring circuit and the second voltage monitoring circuit to separately monitor the opening loop or the closing loop. That is, the first digital input circuit collects the state of the normally closed auxiliary contact of the circuit breaker, and the first voltage monitoring circuit collects the voltage across the normally closed contact of the circuit breaker in the closing loop. When the state of the normally closed auxiliary contact of the circuit breaker is open and the first voltage value is less than the preset voltage threshold, it indicates that the voltage difference across the normally closed contact of the circuit breaker in the closing loop decreases in the closing state, so it can be determined that the closing loop is abnormal in the closing state. Similarly, the second digital input circuit collects the state of the normally open auxiliary contact of the circuit breaker, and the second voltage monitoring circuit collects the voltage across the normally open contact of the circuit breaker in the opening loop. When the state of the normally open auxiliary contact of the circuit breaker is open and the second voltage value is less than the preset voltage threshold, it can be determined that the opening loop is abnormal in the opening state. By configuring two digital input circuits to respectively collect the states of the normally open auxiliary contact and the normally closed auxiliary contact of the circuit breaker, the opening and closing states of the circuit breaker can be more accurately discriminated, and the independent monitoring of the closing loop and the opening loop can be realized, improving the flexibility of monitoring.

[0032] In an embodiment of the present invention, for further illustration and limitation, the system further includes a control loop open circuit, and the alarm circuit includes a first alarm circuit and a second alarm circuit. Among them, through the first alarm circuit, a closing loop alarm signal is output, and through the second alarm circuit, an opening loop alarm signal is output. Through the central control module, when the state of the normally closed auxiliary contact of the circuit breaker is closed, the output of the first alarm circuit is inhibited to output a closing loop alarm signal in the opening state through the control loop open circuit; when the state of the normally open auxiliary contact of the circuit breaker is closed, the output of the second alarm circuit is inhibited to output an opening loop alarm signal in the closing state through the control loop open circuit. The control loop open circuit includes the normally closed contacts of the closing position relay and the normally closed contacts of the opening position relay connected in series. The control loop open circuit outputs a closing loop alarm signal in the opening state or an opening loop alarm signal in the closing state according to the opening and closing states of the circuit breaker when both the normally closed contacts of the closing position relay and the normally closed contacts of the opening position relay are closed, that is, outputs a closing loop alarm signal in the opening state of the circuit breaker and outputs an opening loop alarm signal in the closing state of the circuit breaker.

[0033] In the embodiment of the present invention, the output contacts of the first warning circuit and the second warning circuit are connected to the output end of the control loop disconnection circuit to output a warning signal in parallel with the control loop disconnection circuit. That is, in the closed state of the circuit breaker, the abnormality of the closing loop is output by the first warning circuit, and the abnormality of the opening loop is output by the control loop disconnection circuit; in the open state of the circuit breaker, the abnormality of the closing loop is output by the control loop disconnection circuit, and the abnormality of the opening loop is output by the second warning circuit. It should be noted that in the open state of the circuit breaker (the normally closed auxiliary contact of the circuit breaker is in the closed state), the normally closed contact of the closing loop of the circuit breaker is in the closed state, which is equivalent to the working condition of loop disconnection. To prevent false warnings in this state, when the normally closed auxiliary contact of the circuit breaker is in the closed state, the output of the first warning circuit is suppressed, and the monitoring result of the closing loop is judged according to the output of the control loop disconnection circuit. In the closed state of the circuit breaker (the normally open auxiliary contact of the circuit breaker is in the closed state), the normally open contact of the opening loop of the circuit breaker is in the closed state, which is equivalent to the working condition of loop disconnection. To prevent false warnings in this state, when the normally open auxiliary contact of the circuit breaker is in the closed state, the output of the second warning circuit is suppressed, and the monitoring result of the opening loop is judged according to the output of the control loop disconnection circuit. Among them, a DC 24V voltage is input to the normally open auxiliary contact and the normally closed auxiliary contact of the circuit breaker through the digital input / output loop to monitor the open and closed states of the auxiliary contacts.

[0034] In an embodiment of the present invention, for further illustration and limitation, the first voltage monitoring circuit includes a first sampling circuit, a first amplifying circuit, and a first analog-to-digital conversion circuit, and the second voltage detection circuit includes a second sampling circuit, a second amplifying circuit, and a second analog-to-digital conversion circuit; Among them, the first voltage analog signal across the normally closed contact of the circuit breaker in the closing loop of the circuit breaker is collected through the first sampling circuit; the first amplifying circuit is used to amplify the first voltage analog signal to obtain the amplified first voltage analog signal; through the first analog-to-digital conversion circuit, the amplified first voltage analog signal is converted into a digital signal to obtain the first voltage value; the second voltage analog signal across the normally open contact of the circuit breaker in the opening loop of the circuit breaker is collected through the second sampling circuit; through the second amplifying circuit, the second voltage analog signal is amplified to obtain the amplified second voltage analog signal; through the second analog-to-digital conversion circuit, the amplified second voltage analog signal is converted into a digital signal to obtain the second voltage value.

[0035] In the embodiment of the present invention, the structural composition block diagram of the circuit breaker closing and opening loop monitor can be as Figure 7As shown in the figure, it includes a first voltage sampling circuit, a first amplification circuit and a first analog-to-digital conversion circuit, a second voltage sampling circuit, a second amplification circuit and a second analog-to-digital conversion circuit, a human-computer interaction module, a first digital input circuit, a second digital input circuit, an alarm circuit, a communication module, a power management module, a storage module and a digital output module. Among them, the central control module can be a microcontroller or a single-chip microcomputer. The human-computer interaction module provides interactive operations such as displaying and setting operating parameters, status, and potential values, and can be an OLED display screen. The alarm circuit provides one or two sets of normally open contact alarm output modes. The communication module provides a channel for remote data interaction. The storage module is used to store operating parameters such as preset voltage thresholds and other threshold data, monitoring modes, and alarm modes. The digital output module is used for hard contact output of operating and alarm status. As Figure 8 As shown in the figure, it is a schematic diagram of the appearance of a prototype of a circuit breaker closing and opening loop monitor. Among them, 1 is an OLED display screen, 2 is an LED indicator light, the red light indicates the alarm status, and the green light indicates the operating status. 3 is a button, and the button function table is shown in Table 1 below.

[0036] Table 1:

[0037] The present invention provides a circuit breaker closing and opening loop monitoring system. In the embodiment of the present invention, the digital input circuit is connected to the auxiliary contact of the circuit breaker, and the state of the auxiliary contact is collected through the digital input circuit; the two input contacts of the first voltage monitoring circuit are respectively connected to both ends of the normally closed contact of the circuit breaker in the closing loop of the circuit breaker, and the first voltage value at both ends of the normally closed contact of the circuit breaker is collected through the first voltage monitoring circuit; the two input contacts of the second voltage monitoring circuit are respectively connected to both ends of the normally open contact of the circuit breaker in the opening loop of the circuit breaker, and the second voltage value at both ends of the normally open contact of the circuit breaker is collected through the second voltage monitoring circuit; through the central control module, the preset voltage threshold and the state of the auxiliary contact are obtained. When it is determined that the circuit breaker is in the closing state based on the state of the auxiliary contact and the first voltage value is less than the preset voltage threshold, an alarm signal for the closing loop in the closing state is output through the alarm circuit. When it is determined that the circuit breaker is in the opening state based on the state of the auxiliary contact and the second voltage value is less than the preset voltage threshold, an alarm signal for the opening loop in the opening state is output through the alarm circuit; through the alarm circuit, under the control of the central control module, an alarm signal is output, realizing the monitoring of the closing loop in the closing state of the circuit breaker and the opening loop in the opening state of the circuit breaker, greatly increasing the comprehensiveness of the monitoring of the circuit breaker closing and opening loops, making up for the shortcomings of existing monitoring means, and thus improving the accuracy of the monitoring of the circuit breaker closing and opening loops. Further, as for the implementation of the above Figure 1 system, the embodiment of the present invention provides a method for monitoring a circuit breaker closing and opening loop, and the method includes: Obtain the preset voltage threshold and the status of the auxiliary contact collected by the digital input circuit, where the digital input circuit is connected to the auxiliary contact of the circuit breaker, and the status of the auxiliary contact is synchronously switched along with the opening and closing status of the circuit breaker; Collect the first voltage value across the normally closed contact of the circuit breaker in the closing loop of the circuit breaker through two input contacts of the first voltage monitoring circuit, where the two input contacts of the first voltage monitoring circuit are respectively connected across the normally closed contact of the circuit breaker in the closing loop of the circuit breaker; Collect the second voltage value across the normally open contact of the circuit breaker in the opening loop of the circuit breaker through two input contacts of the second voltage monitoring circuit, where the two input contacts of the second voltage monitoring circuit are respectively connected across the normally open contact of the circuit breaker in the opening loop of the circuit breaker; When it is determined that the circuit breaker is in the closing state based on the status of the auxiliary contact and the first voltage value is less than the preset voltage threshold, control the alarm circuit to output an alarm signal for the closing loop in the closing state; When it is determined that the circuit breaker is in the opening state based on the status of the auxiliary contact and the second voltage value is less than the preset voltage threshold, control the alarm circuit to output an alarm signal for the opening loop in the opening state; Wherein, both the first voltage monitoring circuit and the second voltage monitoring circuit include a high-impedance resistor voltage division circuit to not affect the operation of the closing and opening loops during voltage acquisition.

[0038] Further, when the anti-trip loop of the circuit breaker mechanism is connected to the closing and opening loops of the circuit breaker, the closing loop of the circuit breaker includes a newly added normally closed contact of the circuit breaker and a normally closed contact of the anti-trip relay connected in series to inhibit the mutual activation of the opening position relay and the anti-trip relay; before collecting the first voltage value across the normally closed contact of the circuit breaker in the closing loop of the circuit breaker through two input contacts of the first voltage monitoring circuit, the method further includes: Replace the newly added normally closed contact of the circuit breaker and the normally closed contact of the anti-trip relay connected in series in the closing loop of the circuit breaker with a voltage division resistor so that the voltage division of the opening position relay and the anti-trip relay is respectively less than their respective starting voltages and the first voltage monitoring circuit can be conducted.

[0039] Further, the digital input circuit includes a first digital input circuit and a second digital input circuit, and the status of the auxiliary contact includes the status of the normally closed auxiliary contact of the circuit breaker and the status of the normally closed auxiliary contact of the circuit breaker; determining the closing and opening status of the circuit breaker based on the status of the auxiliary contact includes: Collect the status of the normally closed auxiliary contact of the circuit breaker through the first digital input circuit, and when the status of the normally closed auxiliary contact of the circuit breaker is open, determine that the circuit breaker is in the closing state; Collect the status of the normally open auxiliary contact of the circuit breaker through the second digital input circuit. When the status of the normally open auxiliary contact of the circuit breaker is open, determine that the circuit breaker is in the open state.

[0040] Further, the alarm circuit includes a first alarm circuit and a second alarm circuit. Among them, the output contacts of the first alarm circuit and the second alarm circuit are connected to the output end of the control loop open circuit to output an alarm signal in parallel with the control loop open circuit. The control loop open circuit includes normally closed contacts of the closing position relay and normally closed contacts of the opening position relay connected in series. The control loop open circuit outputs an alarm signal for the opening loop in the closing state or an alarm signal for the closing loop in the opening state according to the status of the circuit breaker when both the normally closed contacts of the closing position relay and the normally closed contacts of the opening position relay are closed; When the status of the normally closed auxiliary contact of the circuit breaker is closed, suppress the output of the first alarm circuit to output an alarm signal for the closing loop in the opening state through the control loop open circuit; When the status of the normally open auxiliary contact of the circuit breaker is closed, suppress the output of the second alarm circuit to output an alarm signal for the opening loop in the closing state through the control loop open circuit.

[0041] Further, the first voltage monitoring circuit includes a first sampling circuit, a first amplifying circuit and a first analog-to-digital conversion circuit, and the second voltage detection circuit includes a second sampling circuit, a second amplifying circuit and a second analog-to-digital conversion circuit; The collection of the first voltage value across the normally closed contact of the circuit breaker in the closing loop of the circuit breaker through the two input contacts of the first voltage monitoring circuit includes: Collect the first voltage analog signal across the normally closed contact of the circuit breaker in the closing loop of the circuit breaker through the first sampling circuit, amplify the first voltage analog signal through the first amplifying circuit to obtain the amplified first voltage analog signal, and convert the amplified first voltage analog signal into a digital signal through the first analog-to-digital conversion circuit to obtain the first voltage value; The collection of the second voltage value across the normally open contact of the circuit breaker in the opening loop of the circuit breaker through the two input contacts of the second voltage monitoring circuit includes: Collect the second voltage analog signal across the normally open contact of the circuit breaker in the opening loop of the circuit breaker through the second sampling circuit, amplify the second voltage analog signal through the second amplifying circuit to obtain the amplified second voltage analog signal, and convert the amplified second voltage analog signal into a digital signal through the second analog-to-digital conversion circuit to obtain the second voltage value.

[0042] The present invention provides a method for monitoring the closing and opening circuits of a circuit breaker. In the embodiments of the present invention, a switch input circuit is connected to the auxiliary contact of the circuit breaker, and the state of the auxiliary contact is collected through the switch input circuit; two input contacts of the first voltage monitoring circuit are respectively connected to both ends of the normally closed contact of the circuit breaker in the closing circuit of the circuit breaker, and the first voltage value at both ends of the normally closed contact of the circuit breaker is collected through the first voltage monitoring circuit; two input contacts of the second voltage monitoring circuit are respectively connected to both ends of the normally open contact of the circuit breaker in the opening circuit of the circuit breaker, and the second voltage value at both ends of the normally open contact of the circuit breaker is collected through the second voltage monitoring circuit; through the central control module, a preset voltage threshold and the state of the auxiliary contact are obtained. When it is determined that the circuit breaker is in the closing state based on the state of the auxiliary contact and the first voltage value is less than the preset voltage threshold, an alarm signal for the closing circuit in the closing state is output through the alarm circuit. When it is determined that the circuit breaker is in the opening state based on the state of the auxiliary contact and the second voltage value is less than the preset voltage threshold, an alarm signal for the opening circuit in the opening state is output through the alarm circuit; through the alarm circuit, under the control of the central control module, an alarm signal is output, realizing the monitoring of the closing circuit in the closing state of the circuit breaker and the opening circuit in the opening state of the circuit breaker, greatly increasing the comprehensiveness of the monitoring of the closing and opening circuits of the circuit breaker, making up for the shortcomings of existing monitoring means, and thus improving the accuracy of the monitoring of the closing and opening circuits of the circuit breaker. Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present invention can be implemented by a general-purpose computing device. They can be concentrated on a single computing device or distributed on a network composed of multiple computing devices. Optionally, they can be implemented by program codes executable by the computing device. Thus, they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described herein can be executed in a different order, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module to be implemented. In this way, the present invention is not limited to any specific combination of hardware and software.

[0043] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A circuit breaker opening and closing circuit monitoring system, characterized in that: It includes a circuit breaker auxiliary contact and a circuit breaker opening and closing circuit monitor, and the circuit breaker opening and closing circuit monitor includes a switch input circuit, a first voltage monitoring circuit, a second voltage monitoring circuit, a central control module and an alarm circuit; The switch input circuit is connected to the auxiliary contact of the circuit breaker and is used to collect the state of the auxiliary contact, wherein the state of the auxiliary contact is switched synchronously with the opening and closing state of the circuit breaker; The two input contacts of the first voltage monitoring circuit are respectively connected to the two ends of the normally closed contact of the circuit breaker in the circuit breaker closing circuit, and are used to collect the first voltage value at the two ends of the normally closed contact of the circuit breaker; The two input contacts of the second voltage monitoring circuit are respectively connected to the two ends of the normally open contacts of the circuit breaker in the circuit breaker opening circuit, and are used to collect the second voltage value at the two ends of the normally open contacts of the circuit breaker; The central control module is used to obtain a preset voltage threshold and the state of the auxiliary contact, and when it is determined that the circuit breaker is in a closed state according to the state of the auxiliary contact and the first voltage value is less than the preset voltage threshold, the alarm circuit outputs a closing circuit alarm signal in the closed state through the alarm circuit; when it is determined that the circuit breaker is in an open state according to the state of the auxiliary contact and the second voltage value is less than the preset voltage threshold, the alarm circuit outputs an opening circuit alarm signal in the open state through the alarm circuit; The alarm circuit is used to output an alarm signal under the control of the central control module; Wherein, the first voltage monitoring circuit and the second voltage monitoring circuit both include a high-impedance resistor voltage divider circuit so as not to affect the operation of the opening and closing circuits during the voltage acquisition process.

2. The circuit breaker opening and closing circuit monitoring system according to claim 1, characterized in that: In the case where the circuit breaker opening and closing circuit is connected to the circuit breaker mechanism anti-tripping circuit, the circuit breaker closing circuit includes a newly added circuit breaker normally closed contact and an anti-tripping relay normally closed contact connected in series to inhibit the opening position relay and the anti-tripping relay from starting each other, and the system includes a voltage dividing resistor; The voltage-dividing resistor is used to replace the normally closed contacts of the circuit breaker and the normally closed contacts of the anti-tripping relay connected in series in the circuit breaker closing circuit before the first voltage monitoring circuit collects the first voltage value, so that the voltage division of the opening position relay and the anti-tripping relay is adjusted to be smaller than their respective starting voltages, and the first voltage monitoring circuit can be turned on, wherein the newly added normally closed contacts of the circuit breaker in the circuit breaker closing circuit are connected in series with the normally closed contacts of the anti-tripping relay to inhibit the opening position relay and the anti-tripping relay from starting each other.

3. The circuit breaker opening and closing circuit monitoring system according to claim 1, characterized in that: The switch value input circuit includes a first switch value input circuit and a second switch value input circuit; The first switch input circuit is used to collect the state of the normally closed auxiliary contact of the circuit breaker; The second switch input circuit is used to collect the state of the normally open auxiliary contact of the circuit breaker; The central control module is also used to determine that the circuit breaker is in a closed state when the normally closed auxiliary contact state of the circuit breaker is disconnected; and to determine that the circuit breaker is in an open state when the normally open auxiliary contact state of the circuit breaker is disconnected.

4. The circuit breaker opening and closing circuit monitoring system according to claim 3 is characterized in that: The system further comprises a control loop disconnection circuit, and the alarm circuit comprises a first alarm circuit and a second alarm circuit; The control circuit disconnection circuit comprises a normally closed contact of a closing position relay and a normally closed contact of an opening position relay connected in series. When the normally closed contact of the closing position relay and the normally closed contact of the opening position relay are both closed, the control circuit disconnection circuit outputs an open circuit alarm signal in a closing state or a closing circuit alarm signal in an open state according to the opening and closing states of the circuit breaker; The first alarm circuit is used to output a closing circuit alarm signal, and the second alarm circuit is used to output an opening circuit alarm signal, wherein the output contacts of the first alarm circuit and the second alarm circuit are connected to the output end of the control circuit disconnection circuit to output the alarm signal in parallel with the control circuit disconnection circuit; The central control module is also used to suppress the output of the first alarm circuit when the normally closed auxiliary contact state of the circuit breaker is closed, so as to output the closing circuit alarm signal in the opening state through the control circuit disconnection circuit; and suppress the output of the second alarm circuit when the normally open auxiliary contact state of the circuit breaker is closed, so as to output the opening circuit alarm signal in the closing state through the control circuit disconnection circuit.

5. The circuit breaker opening and closing circuit monitoring system according to claim 1, characterized in that: The first voltage monitoring circuit includes a first sampling circuit, a first amplifying circuit and a first analog-to-digital conversion circuit, and the second voltage detection circuit includes a second sampling circuit, a second amplifying circuit and a second analog-to-digital conversion circuit; The first sampling circuit is used to collect a first voltage analog signal at both ends of a normally closed contact of a circuit breaker in a circuit breaker closing circuit; The first amplifier circuit is used to amplify the first voltage analog signal to obtain an amplified first voltage analog signal; The first analog-to-digital conversion circuit is used to convert the amplified first voltage analog signal into a digital signal to obtain a first voltage value; The second sampling circuit is used to collect a second voltage analog signal at both ends of the normally open contacts of the circuit breaker in the circuit breaker opening circuit; The second amplifier circuit is used to amplify the second voltage analog signal to obtain an amplified second voltage analog signal; The second analog-to-digital conversion circuit is used to convert the amplified second voltage analog signal into a digital signal to obtain a second voltage value.

6. A circuit breaker opening and closing circuit monitoring method, characterized in that: include: Acquire a preset voltage threshold and an auxiliary contact state collected by a switch input circuit, wherein the switch input circuit is connected to the auxiliary contact of the circuit breaker, and the auxiliary contact state switches synchronously with the opening and closing state of the circuit breaker; Collecting a first voltage value at both ends of a normally closed contact of a circuit breaker in a circuit breaker closing circuit through two input contacts of a first voltage monitoring circuit, wherein the two input contacts of the first voltage monitoring circuit are respectively connected to both ends of a normally closed contact of a circuit breaker in a circuit breaker closing circuit; The second voltage value at both ends of the normally open contact of the circuit breaker in the circuit breaker opening circuit is collected through two input contacts of the second voltage monitoring circuit, wherein the two input contacts of the second voltage monitoring circuit are respectively connected to both ends of the normally open contact of the circuit breaker in the circuit breaker opening circuit; When it is determined that the circuit breaker is in the closed state according to the auxiliary contact state, and the first voltage value is less than the preset voltage threshold, the alarm circuit is controlled to output a closing circuit alarm signal in the closed state; When it is determined that the circuit breaker is in an open state according to the auxiliary contact state, and the second voltage value is less than the preset voltage threshold, the alarm circuit is controlled to output an open circuit alarm signal in the open state; Wherein, the first voltage monitoring circuit and the second voltage monitoring circuit both include a high-impedance resistor voltage divider circuit so as not to affect the operation of the opening and closing circuits during the voltage acquisition process.

7. The method according to claim 6, characterized in that In the case where the circuit breaker opening and closing circuit is connected to the circuit breaker mechanism anti-tripping circuit, the circuit breaker closing circuit includes a newly added circuit breaker normally closed contact and an anti-tripping relay normally closed contact connected in series to inhibit the opening position relay and the anti-tripping relay from starting each other; before collecting the first voltage value at both ends of the circuit breaker normally closed contact in the circuit breaker closing circuit through the two input contacts of the first voltage monitoring circuit, the method also includes: The normally closed contacts of the newly added circuit breaker and the normally closed contacts of the anti-tripping relay connected in series in the circuit breaker closing circuit are replaced with voltage-dividing resistors so that the voltage-dividing resistors of the adjusting opening position relay and the anti-tripping relay are respectively smaller than their respective starting voltages, and the first voltage monitoring circuit can be turned on.

8. The method according to claim 6, characterized in that The switch input circuit includes a first switch input circuit and a second switch input circuit, and the auxiliary contact state includes a circuit breaker normally closed auxiliary contact state and a circuit breaker normally closed auxiliary contact state; Determine the circuit breaker opening and closing status based on the auxiliary contact status, including: The state of the normally closed auxiliary contact of the circuit breaker is collected through the first switch input circuit, and when the state of the normally closed auxiliary contact of the circuit breaker is open, it is determined that the circuit breaker is in the closed state; The state of the normally open auxiliary contact of the circuit breaker is collected through the second switch input circuit, and when the state of the normally open auxiliary contact of the circuit breaker is disconnected, it is determined that the circuit breaker is in the open state.

9. The method according to claim 6, characterized in that The alarm circuit comprises a first alarm circuit and a second alarm circuit, wherein the output contacts of the first alarm circuit and the second alarm circuit are connected to the output end of the control loop disconnection circuit to output an alarm signal in parallel with the control loop disconnection circuit, the control loop disconnection circuit comprises a normally closed contact of a closing position relay and a normally closed contact of an opening position relay connected in series, and the control loop disconnection circuit outputs an opening circuit alarm signal in a closing state or a closing circuit alarm signal in an opening state according to the state of the circuit breaker when the normally closed contact of the closing position relay and the normally closed contact of the opening position relay are both closed; When the normally closed auxiliary contact of the circuit breaker is in a closed state, the output of the first alarm circuit is suppressed, so as to output a closing circuit alarm signal in an open state through the control circuit disconnection circuit; When the normally open auxiliary contact of the circuit breaker is in a closed state, the output of the second alarm circuit is suppressed, so as to output an opening circuit alarm signal in a closed state through the control circuit disconnection circuit.

10. The method according to claim 6, characterized in that The first voltage monitoring circuit includes a first sampling circuit, a first amplifying circuit and a first analog-to-digital conversion circuit, and the second voltage detection circuit includes a second sampling circuit, a second amplifying circuit and a second analog-to-digital conversion circuit; The method of collecting the first voltage value at both ends of the normally closed contacts of the circuit breaker in the circuit breaker closing circuit through the two input contacts of the first voltage monitoring circuit includes: collecting a first voltage analog signal at both ends of a normally closed contact of a circuit breaker in a circuit breaker closing circuit by means of the first sampling circuit, amplifying the first voltage analog signal by means of the first amplifying circuit to obtain an amplified first voltage analog signal, and converting the amplified first voltage analog signal by means of the first analog-to-digital conversion circuit to a digital signal to obtain a first voltage value; The collecting of the second voltage value at both ends of the normally open contacts of the circuit breaker in the circuit breaker opening circuit through the two input contacts of the second voltage monitoring circuit comprises: The second sampling circuit collects the second voltage analog signal at both ends of the normally open contacts of the circuit breaker in the circuit breaker opening circuit, the second voltage analog signal is amplified by the second amplifying circuit to obtain the amplified second voltage analog signal, and the second analog-to-digital conversion circuit converts the amplified second voltage analog signal into a digital signal to obtain a second voltage value.

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