Disclosure of Invention
In view of the above, the invention provides a circuit breaker opening and closing loop monitoring system, which mainly aims to solve the problem of lower monitoring accuracy of the existing circuit breaker opening and closing loop.
According to one aspect of the invention, a breaker opening and closing loop monitoring system is provided, which comprises a breaker auxiliary contact and a breaker opening and closing loop monitor, wherein the 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 switching value input circuit is connected with the auxiliary contact of the circuit breaker and used for collecting the state of the auxiliary contact, wherein the state of the auxiliary contact is synchronously switched along with the switching state conversion of the switching state of the circuit breaker;
Two input contacts of the first voltage monitoring circuit are respectively connected with two ends of a normally-closed contact of a circuit breaker in a circuit breaker closing loop and are used for collecting first voltage values of the two ends of the normally-closed contact of the circuit breaker;
Two input contacts of the second voltage monitoring circuit are respectively connected with two ends of a normally open contact of a breaker in a breaking loop of the breaker and are used for collecting second voltage values of the two ends of the normally open contact of the breaker;
The central control module is used for acquiring a preset voltage threshold value and the auxiliary contact state, outputting a closing loop alarm signal in the closing state through the alarm circuit when the circuit breaker is determined to be in the closing state according to the auxiliary contact state and the first voltage value is smaller than the preset voltage threshold value, and outputting a closing loop alarm signal in the opening state through the alarm circuit when the circuit breaker is determined to be in the opening state according to the auxiliary contact state and the second voltage value is smaller than the preset voltage threshold value;
the alarm circuit is used for outputting alarm signals under the control of the central control module;
the first voltage monitoring circuit and the second voltage monitoring circuit both comprise high-impedance resistor voltage dividing circuits so as not to influence the operation of the opening and closing loop in the voltage acquisition process.
Further, under the condition that a breaker opening and closing loop is connected into an anti-tripping loop of a breaker mechanism, the breaker closing loop comprises a newly-added breaker normally-closed contact and an anti-tripping relay normally-closed contact which are connected in series so as to inhibit the relay and the anti-tripping relay at the opening and closing position from being mutually started, and the system comprises a voltage dividing resistor;
The voltage dividing resistor is used for replacing a normally-closed contact of the circuit breaker and a normally-closed contact of the anti-tripping relay which are connected in series in the circuit breaker closing loop before the first voltage monitoring circuit collects a first voltage value, so that the voltage division of the relay at the position of the switching-off regulation and the anti-tripping relay is respectively smaller than respective starting voltage, and the first voltage monitoring circuit can be conducted, wherein the normally-closed contact of the newly-added circuit breaker in the circuit breaker closing loop is connected in series with the normally-closed contact of the anti-tripping relay, and the relay at the switching-off position and the anti-tripping relay are restrained from being mutually started.
Further, the switching value input circuit comprises a first switching value input circuit and a second switching value input circuit;
The first switching value input circuit is used for acquiring the normally closed auxiliary contact state of the circuit breaker;
the second switching value input circuit is used for acquiring the state of a normally open auxiliary contact of the circuit breaker;
The central control module is also used for determining that the circuit breaker is in a closing state when the normally-closed auxiliary contact state of the circuit breaker is open, and determining that the circuit breaker is in a breaking state when the normally-open auxiliary contact state of the circuit breaker is open.
Further, the system also comprises a control loop disconnection circuit, wherein the alarm circuit comprises a first alarm circuit and a second alarm circuit;
The control loop wire-breaking circuit comprises a normally closed contact of a switching-on position relay and a normally closed contact of a switching-off position relay which are connected in series, and outputs a switching-off loop alarm signal in a switching-on state or a switching-off loop alarm signal in a switching-off state according to a switching-off state of the circuit breaker under the condition that the normally closed contact of the switching-on position relay and the normally closed contact of the switching-off position relay are closed;
The first alarm circuit is used for outputting a closing loop alarm signal, and the second alarm circuit is used for outputting a separating loop alarm signal, wherein output joints of the first alarm circuit and the second alarm circuit are connected with an output end of a control loop wire-breaking circuit so as to output the alarm signal in parallel with the control loop wire-breaking circuit;
the central control module is also used for inhibiting the output of the first alarm circuit to output the alarm signal of the switching-on loop in the switching-off state through the control loop wire-breaking circuit under the condition that the normally closed auxiliary contact state of the circuit breaker is closed, and inhibiting the output of the second alarm circuit to output the alarm signal of the switching-off loop in the switching-on state through the control loop wire-breaking circuit under the condition that the normally open auxiliary contact state of the circuit breaker is closed.
Further, the first voltage monitoring circuit comprises a first sampling circuit, a first amplifying circuit and a first analog-to-digital conversion circuit, and the second voltage detecting circuit comprises a second sampling circuit, a second amplifying circuit and a second analog-to-digital conversion circuit;
the first sampling circuit is used for collecting first voltage analog signals at two ends of a normally-closed contact of the circuit breaker in the circuit breaker closing circuit;
the first amplifying circuit is used for amplifying the first voltage analog signal to obtain an amplified first voltage analog signal;
The first analog-to-digital conversion circuit is used for converting the amplified first voltage analog signal into a digital signal to obtain a first voltage value;
The second sampling circuit is used for collecting second voltage analog signals at two ends of a normally open contact of the breaker in the breaking loop of the breaker;
The second amplifying circuit is used for amplifying the second voltage analog signal to obtain an amplified second voltage analog signal;
and the second analog-to-digital conversion circuit is used for carrying out digital signal conversion on the amplified second voltage analog signal to obtain a second voltage value.
According to another aspect of the present invention, there is provided a method for monitoring a switching circuit of a circuit breaker, including:
Acquiring a preset voltage threshold value and an auxiliary contact state acquired by a switching value input circuit, wherein the switching value input circuit is connected with an auxiliary contact of a circuit breaker, and the auxiliary contact state is synchronously switched along with switching state conversion of the circuit breaker;
Collecting first voltage values of two 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 with two ends of the normally-closed contact of the circuit breaker in the circuit breaker closing circuit;
Collecting second voltage values of two ends of a normally open contact of a breaker in a breaking loop of the breaker through two input contacts of a second voltage monitoring circuit, wherein the two input contacts of the second voltage monitoring circuit are respectively connected with two ends of the normally open contact of the breaker in the breaking loop of the breaker;
when the circuit breaker is determined to be in a closing state according to the auxiliary contact state, and the first voltage value is smaller than a preset voltage threshold value, the control alarm circuit outputs a closing loop alarm signal in the closing state;
When the breaker is determined to be in a brake-off state according to the auxiliary contact state, and the second voltage value is smaller than the preset voltage threshold value, the control alarm circuit outputs a brake-off loop alarm signal in the brake-off state;
the first voltage monitoring circuit and the second voltage monitoring circuit both comprise high-impedance resistor voltage dividing circuits so as not to influence the operation of the opening and closing loop in the voltage acquisition process.
Further, under the condition that a breaker opening and closing loop is connected into an anti-tripping loop of a breaker mechanism, the breaker closing loop comprises a newly-added breaker normally-closed contact and an anti-tripping relay normally-closed contact which are connected in series, so that the relay and the anti-tripping relay at the opening and closing position are restrained from being mutually started;
Before the first voltage values at two ends of the normally-closed contact of the circuit breaker in the circuit breaker closing loop are collected through the two input contacts of the first voltage monitoring circuit, the method further comprises the following steps:
And replacing the normally closed contact of the newly-added breaker and the normally closed contact of the anti-tripping relay which are connected in series in the breaker closing loop with voltage dividing resistors, so that the voltage dividing of the relay for adjusting the opening position and the anti-tripping relay is respectively smaller than the respective starting voltage, and the first voltage monitoring circuit can be conducted.
Further, the switching value input circuit comprises a first switching value input circuit and a second switching value input circuit, the auxiliary contact state comprises a normally closed auxiliary contact state of the circuit breaker and a normally closed auxiliary contact state of the circuit breaker, and the switching state of the circuit breaker is determined according to the auxiliary contact state and comprises the following steps:
acquiring a normally closed auxiliary contact state of the circuit breaker through a first switching value input circuit, and determining that the circuit breaker is in a closing state under the condition that the normally closed auxiliary contact state of the circuit breaker is open;
The normally open auxiliary contact state of the circuit breaker is acquired through the second switching value input circuit, and the circuit breaker is determined to be in a breaking state under the condition that the normally open auxiliary contact state of the circuit breaker is broken.
Further, the alarm circuit comprises a first alarm circuit and a second alarm circuit, wherein output contacts of the first alarm circuit and the second alarm circuit are connected with an output end of a control loop wire breaking circuit so as to output alarm signals in parallel with the control loop wire breaking circuit, the control loop wire breaking circuit comprises a normally closed contact of a switching-on position relay and a normally closed contact of a switching-off position relay which are connected in series, and the control loop wire breaking circuit outputs switching-off loop alarm signals in a switching-on state or switching-off loop alarm signals in a switching-off state according to the state of a circuit breaker under the condition that the normally closed contact of the switching-on position relay and the normally closed contact of the switching-off position relay are closed;
Under the condition that the normally closed auxiliary contact state of the circuit breaker is closed, inhibiting the output of the first alarm circuit so as to output a closing circuit alarm signal in a breaking state through the control circuit breaking circuit;
And under the condition that the normally open auxiliary contact state of the circuit breaker is closed, inhibiting the output of the second alarm circuit so as to output an alarm signal of the opening circuit in the closing state through the control circuit breaking circuit.
Further, the first voltage monitoring circuit comprises a first sampling circuit, a first amplifying circuit and a first analog-to-digital conversion circuit, and the second voltage detecting circuit comprises a second sampling circuit, a second amplifying circuit and a second analog-to-digital conversion circuit;
the first voltage value at two ends of a normally-closed contact of the circuit breaker in the circuit breaker closing loop is collected through two input contacts of a first voltage monitoring circuit, and the circuit breaker closing circuit comprises:
Collecting first voltage analog signals at two ends of a normally-closed contact of a circuit breaker in a circuit breaker closing loop through the first sampling circuit, amplifying the first voltage analog signals through the first amplifying circuit to obtain amplified first voltage analog signals, and converting the amplified first voltage analog signals into digital signals through the first analog-to-digital conversion circuit to obtain first voltage values;
The second voltage value of the two ends of the normally open contact of the breaker in the breaking loop of the breaker is collected through the two input contacts of the second voltage monitoring circuit, and the method comprises the following steps:
And acquiring second voltage analog signals at two ends of a normally open contact of the circuit breaker in the circuit breaker opening loop through the second sampling circuit, amplifying the second voltage analog signals through the second amplifying circuit to obtain amplified second voltage analog signals, and converting the amplified second voltage analog signals into digital signals through the second analog-to-digital conversion circuit to obtain second voltage values.
By means of the technical scheme, the technical scheme provided by the embodiment of the invention has at least the following advantages:
The embodiment of the invention is connected with auxiliary contacts of a circuit breaker through a switching value input circuit, acquires auxiliary contact states through the switching value input circuit, respectively connects two input contacts of a first voltage monitoring circuit with two ends of normally closed contacts of the circuit breaker in the circuit breaker, acquires first voltage values of two ends of the normally closed contacts of the circuit breaker through the first voltage monitoring circuit, respectively connects two input contacts of a second voltage monitoring circuit with two ends of normally open contacts of the circuit breaker in the circuit breaker opening circuit, acquires second voltage values of two ends of the normally open contacts of the circuit breaker through the second voltage monitoring circuit, acquires a preset voltage threshold value and an auxiliary contact state, determines that the circuit breaker is in a closing state according to the auxiliary contact state, and outputs a closing circuit alarm signal through an alarm circuit when the auxiliary contact state is determined that the circuit breaker is in the opening state and the second voltage value is smaller than the preset voltage threshold value, and outputs the opening circuit alarm signal through the alarm circuit, and the alarm circuit breaker opening and closing state is greatly improved by the alarm circuit.
The foregoing description is only an overview of the present invention, and is intended to provide a more clear understanding of the technical means of the present invention, as well as to provide a more clear understanding of the above and other objects, features and advantages of the present invention, as exemplified by the following detailed description.
Detailed Description
Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
The method aims at the problem that the monitoring accuracy of the existing breaker opening and closing loop is low. The embodiment of the invention provides a circuit breaker opening and closing loop monitoring system, as shown in fig. 1, which comprises:
The circuit breaker auxiliary contact 100 and the circuit breaker opening and closing loop monitor 200, wherein the circuit breaker opening and closing loop monitor 200 comprises a switching value 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.
The switching value input circuit 210 is connected with the auxiliary contact 100 of the circuit breaker, the auxiliary contact state is collected through the switching value input circuit 210, two input contacts of the first voltage monitoring circuit 220 are respectively connected with two ends of a normally closed contact of the circuit breaker in a circuit breaker closing loop, a first voltage value of two 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 with two ends of a normally open contact of the circuit breaker in a circuit breaker opening loop, a second voltage value of two ends of the normally open contact of the circuit breaker is collected through the second voltage monitoring circuit 230, a preset voltage threshold and the auxiliary contact state are obtained through the central control module 240, a circuit breaker closing state is determined according to the auxiliary contact state, a closing loop alarm signal is output through the alarm circuit 250 when the first voltage value is smaller than the preset voltage threshold, a circuit breaker opening state is determined according to the auxiliary contact state, and the second voltage value is smaller than the preset voltage threshold, a circuit opening alarm signal is output through the alarm circuit 250 when the circuit opening state is determined according to the auxiliary contact state, and the alarm signal is output through the central control module 230.
The circuit breaker opening and closing loop is used as a loop for controlling the opening and closing of the circuit breaker and comprises a closing loop and a breaking loop. As shown in fig. 2, the switching-on circuit is a conventional switching-off circuit, two ends of the switching-on circuit and the switching-off circuit are connected in parallel and are connected with +/-220V power supply, the switching-on circuit comprises a circuit breaker manual control switch, a circuit breaker normally-closed contact and a switching-on coil which are connected in series, and the switching-off circuit comprises a circuit breaker manual control switch, a circuit breaker normally-open contact and a switching-off coil which are connected in series.
In the embodiment of the invention, in order to monitor whether the circuit of the opening and closing loop of the circuit breaker is good, the first voltage monitoring circuit 220 of the opening and closing loop monitor 200 of the circuit breaker is connected to two ends of the normally-closed contact of the circuit breaker in the closing loop so as to collect the first voltage value of the two ends of the normally-closed contact of the circuit breaker in the closing loop. The second voltage monitoring circuit 230 is connected to two ends of the normally open contact of the breaker in the breaking loop to collect the second voltage value of two ends of the normally open contact of the breaker in the breaking loop. Taking a schematic diagram of connection of a switching-in loop of the switching-out and switching-in loop monitor of the circuit breaker as shown in fig. 3 as an example, two input contacts of a first voltage monitoring circuit of the switching-out and switching-in loop monitor of the circuit breaker are respectively connected with two contacts A, B of a normally-closed contact of the circuit breaker in the switching-in loop. When the circuit breaker is in a closing state, a normally-closed contact of the circuit breaker in a closing loop is opened, and at the moment, if the loop is intact, 220V pressure difference exists between two points A, B, namely, the first voltage value is 220V. If the voltage difference between the two points A, B disappears, that is, the first voltage value is smaller than the preset voltage threshold, the closing loop can be judged to be interrupted. The preset voltage threshold may be 0 or a voltage value close to 0, and may be customized according to actual requirements. For the same reason, a schematic diagram of the connection of the opening circuit to the opening circuit of the opening circuit monitor of the circuit breaker is shown in fig. 4. In the breaking loop, when the breaker is in a breaking state, a normally open contact of the breaker in the breaking loop is opened, and at the moment, if the loop is intact, a 220V pressure difference exists between two points C, D, namely, a second voltage value is 220V. If the voltage difference between the two points C, D disappears, that is, the second voltage value is smaller than the preset voltage threshold, it can be determined that the brake-separating loop is interrupted. The above-mentioned judging process based on the comparison result of the preset voltage threshold and the first voltage value or the second voltage value and the opening and closing state of the circuit breaker is executed by the central control module 240, and an alarm signal is output through the alarm circuit in case of judging that the circuit is interrupted. The alarm signal may be notified to the field operation and maintenance personnel in one or more of acoustic, optical and electrical modes, and the embodiment of the present invention is not particularly limited.
The opening and closing state of the circuit breaker is collected by the switching value input circuit 210 of the circuit breaker opening and closing loop monitor 200. Taking a schematic connection diagram of a closing circuit as shown in fig. 3 as an example, a switching value input circuit is connected with auxiliary contacts of a circuit breaker to acquire connection states (auxiliary contact states) of the auxiliary contacts of the circuit breaker, and the auxiliary contact states are synchronously switched along with switching states of the circuit breaker, so that the switching states of the circuit breaker can be judged according to the auxiliary contact states.
It should be noted that, the first voltage monitoring circuit and the second voltage monitoring circuit each include a high-impedance resistor voltage dividing circuit, and specifically, the internal resistance of the resistor voltage dividing circuit is greater than 20M. Because the high impedance of the first voltage monitoring circuit and the second voltage monitoring circuit can not divide the current in the opening or closing loop when being connected with the normally open or normally closed contact of the circuit breaker in parallel, the normal work of the loop is influenced, namely the work of the opening or closing loop is not influenced in the voltage acquisition process.
In one embodiment of the present invention, for further explanation and limitation, the system includes a voltage divider resistor in the case where the circuit breaker opening and closing circuit is connected to the circuit breaker mechanism anti-trip circuit.
Before the first voltage monitoring circuit collects a first voltage value, the normally-closed contact of the circuit breaker and the normally-closed contact of the anti-tripping relay which are connected in series in the circuit breaker closing loop are replaced through the voltage dividing resistor, so that the voltage division of the relay for adjusting the opening position and the voltage division of the anti-tripping relay are respectively smaller than the respective starting voltage, and the first voltage monitoring circuit can be conducted.
The circuit breaker switching-on loop is added with a circuit breaker contact, a tripping prevention relay and a tripping prevention relay normally open (normally closed) contact under the condition that a mechanism tripping prevention mechanism is configured in the circuit breaker to be monitored, namely, the circuit breaker switching-on loop is connected with the circuit breaker mechanism tripping prevention loop. The circuit breaker closing loop is additionally provided with a newly-added circuit breaker normally-closed contact and an anti-tripping relay normally-closed contact which are connected in series, so that the relay and the anti-tripping relay at the opening position are restrained from being mutually started. As shown in fig. 5, the anti-tripping relay, the normally-closed contact of the anti-tripping relay and the normally-open contact of the anti-tripping relay are added in the closing loop, and a breakpoint is newly added, namely the normally-closed contact of the breaker is newly added. When the circuit breaker is in a closing state, a normally closed contact of the newly added circuit breaker is in an opening state, at the moment, the circuit is in a non-conducting state, the voltage between two A, B points is 0, and the connection condition of a circuit breaker opening and closing circuit monitor is not met.
In the embodiment of the invention, the normally-closed contact of the newly-added breaker and the normally-closed contact of the anti-tripping relay which are connected in series in the closing loop are replaced by the voltage dividing resistor. The switching circuit for completing the replacement of the voltage dividing resistor is shown in fig. 6. Wherein the voltage dividing resistor is a high-impedance voltage dividing resistor with kiloohm level or more. The series circuit of the normally closed contact of the newly added breaker and the normally closed contact of the anti-tripping relay is replaced by a voltage dividing resistor, so that the voltage at two ends of the switching-off position relay and the anti-tripping relay is reduced in a voltage dividing mode, the voltage at two ends of the switching-off position relay and the anti-tripping relay is smaller than the corresponding starting voltage, and meanwhile, the conduction state of the switching-on circuit is ensured. Through the transformation, the switching-on loop meets the switching-on condition of the breaker switching-on loop monitor while meeting the tripping-prevention requirement, so that the tripping-prevention mechanism is ensured and the normal monitoring of the breaker switching-on loop monitor on the tripping-off loop is realized under the condition that the breaker switching-on loop is switched on the breaker mechanism tripping-prevention loop.
In one embodiment of the present invention, for further explanation and limitation, the switching value input circuit includes a first switching value input circuit and a second switching value input circuit.
The circuit breaker normally-closed auxiliary contact state is collected through a first switching value input circuit, the normally-closed auxiliary contact state of the circuit breaker is collected through a second switching value input circuit, the circuit breaker is determined to be in a closing state under the condition that the normally-closed auxiliary contact state of the circuit breaker is opened through a central control module, and the circuit breaker is determined to be in a breaking state under the condition that the normally-open auxiliary contact state of the circuit breaker is opened.
In the embodiment of the invention, the breaker opening and closing loop monitor is provided with two first switching value input circuits and two second switching value input circuits, and can respectively form a circuit combination for independently monitoring an opening loop or a closing loop with the first voltage monitoring circuit and the second voltage monitoring circuit. The first switching value input circuit collects the normally-closed auxiliary contact state of the circuit breaker, and the first voltage monitoring circuit collects voltages at two ends of the normally-closed contact of the circuit breaker in the closing loop. When the normally closed auxiliary contact state of the circuit breaker is in an opened state and the first voltage value is smaller than a preset voltage threshold value, the condition that the pressure difference between two ends of the normally closed contact of the circuit breaker of the closing circuit is reduced in the closing state is indicated, and the abnormal closing circuit in the closing state can be determined. And similarly, the second switching value input circuit collects the states of the normally open auxiliary contacts of the circuit breaker, and the second voltage monitoring circuit collects voltages at two ends of the normally open contacts of the circuit breaker in the split-gate loop. When the normally open auxiliary contact state of the circuit breaker is in an opened state and the second voltage value is smaller than a preset voltage threshold value, abnormal opening loop in the opening state can be determined. The states of the normally open auxiliary contact and the normally closed auxiliary contact of the circuit breaker are respectively acquired by configuring the two switching value input circuits, so that the open and close states of the circuit breaker can be more accurately judged, independent monitoring of a closing loop and a separating loop is realized, and the monitoring flexibility is improved.
In one embodiment of the present invention, for further explanation and limitation, the system further comprises a control loop circuit breaker, and the alarm circuit comprises a first alarm circuit and a second alarm circuit.
The switching-on loop alarm signal is output through the first alarm circuit, and the switching-off loop alarm signal is output through the second alarm circuit. And under the condition that the normally open auxiliary contact state of the circuit breaker is closed, suppressing the output of a second warning circuit so as to output a brake-off loop warning signal under the brake-on state through the control loop wire-off circuit. The control loop wire breaking circuit comprises a normally closed contact of a switching-on position relay and a normally closed contact of a switching-off position relay which are connected in series, and outputs a switching-off loop alarm signal in a switching-on state or a switching-on loop alarm signal in a switching-off state according to the switching-on and switching-off state of the circuit breaker under the condition that the normally closed contact of the switching-on position relay and the normally closed contact of the switching-off position relay are both closed, namely, outputs the switching-on loop alarm signal in the switching-off state of the circuit breaker and outputs the switching-off loop alarm signal in the switching-on state of the circuit breaker.
In the embodiment of the invention, the output contact points of the first alarm circuit and the second alarm circuit are connected with the output end of the control loop wire-breaking circuit so as to output alarm signals in parallel with the control loop wire-breaking circuit. The control circuit is used for controlling the switching-on state of the circuit breaker, the switching-off state of the circuit breaker is controlled by the control circuit, and the switching-on state of the circuit breaker is controlled by the control circuit. In addition, in the breaker opening state (the breaker normally-closed auxiliary contact state is closed), the breaker normally-closed contact of the closing circuit is in a closed state, which is equivalent to the working condition of circuit disconnection, in order to prevent false alarm in the state, in the case that the breaker normally-closed auxiliary contact state is closed, the output of the first alarm circuit is inhibited, and the monitoring result of the closing circuit is judged according to the output of the control circuit disconnection circuit. In the closing state of the circuit breaker (the normally open auxiliary contact state of the circuit breaker is closed), the normally open contact of the circuit breaker of the opening circuit is in a closed state and is equivalent to the working condition of circuit disconnection, in order to prevent false alarm in the state, under the condition that the normally open auxiliary contact state of the circuit breaker is closed, the output of the second alarm circuit is inhibited, and the monitoring result of the opening circuit is judged according to the output of the circuit breaking circuit of the control circuit. The direct-current 24V voltage is input to the normally-open auxiliary contact of the circuit breaker and the normally-closed auxiliary contact of the circuit breaker through the switching value loop so as to monitor the opening and closing states of the auxiliary contacts.
In an embodiment of the present invention, for further explanation 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 detecting circuit includes a second sampling circuit, a second amplifying circuit and a second analog-to-digital conversion circuit;
The circuit comprises a first sampling circuit, a first amplifying circuit, a first analog-to-digital conversion circuit, a second sampling circuit, a second amplifying circuit and a second analog-to-digital conversion circuit, wherein the first analog-to-digital conversion circuit is used for acquiring first voltage analog signals at two ends of a normally-closed contact of a circuit breaker in a circuit breaker closing loop, the first amplifying circuit is used for amplifying the first voltage analog signals to obtain amplified first voltage analog signals, the first analog-to-digital conversion circuit is used for converting the amplified first voltage analog signals to digital signals to obtain first voltage values, the second sampling circuit is used for acquiring second voltage analog signals at two ends of a normally-open contact of the circuit breaker in a circuit breaker opening loop, the second amplifying circuit is used for amplifying the second voltage analog signals to obtain amplified second voltage analog signals, and the second analog-to-digital conversion circuit is used for converting the amplified second voltage analog signals to digital signals to obtain second voltage values.
In the embodiment of the invention, a structural block diagram of the breaker opening and closing loop monitor can be shown as fig. 7, and the circuit comprises a first voltage sampling circuit, a first amplifying circuit, a first analog-to-digital conversion circuit, a second voltage sampling circuit, a second amplifying circuit, a second analog-to-digital conversion circuit, a man-machine interaction module, a first switching value input circuit, a second switching value input circuit, an alarm circuit, a communication module, a power management module, a storage module and a switching value output module. The central control module can be a microcontroller or a singlechip. The man-machine interaction module provides interactive operations such as display, setting and the like of operation parameters, states and potential values, and can be an OLED display screen. The alarm circuit provides one or two pairs of empty contact alarm output modes. The communication module provides a channel for remote data interaction. The storage module is used for storing operation parameters such as a preset voltage threshold value and other threshold value data, a monitoring mode, an alarm mode and the like. The switching value output module is used for outputting the hard contact in the operation and alarm state. Fig. 8 is a schematic diagram showing the appearance of a prototype of a circuit breaker opening and closing loop monitor. Wherein, 1 is OLED display screen, and 2 is LED pilot lamp, and red instruction alarm state, green lamp indicate running state. 3 is a key, and the key function table is shown in table 1 below.
Table 1:
The embodiment of the invention provides a circuit breaker opening and closing loop monitoring system, which is connected with auxiliary contacts of a circuit breaker through a switching value input circuit and acquires the states of the auxiliary contacts through the switching value input circuit, wherein two input contacts of a first voltage monitoring circuit are respectively connected with two ends of normally closed contacts of the circuit breaker in a circuit breaker closing loop, a first voltage value of the two ends of the normally closed contacts of the circuit breaker is acquired through the first voltage monitoring circuit, two input contacts of a second voltage monitoring circuit are respectively connected with two ends of normally open contacts of the circuit breaker in the circuit breaker opening and closing loop, a second voltage value of the two ends of the normally open contacts of the circuit breaker is acquired through the second voltage monitoring circuit, a preset voltage threshold and the states of the auxiliary contacts are acquired through a central control module, a closing loop alarm signal is output through an alarm circuit when the states of the auxiliary contacts are determined to be the closing states, and the alarm circuit breaker is in the opening states when the states of the auxiliary contacts are smaller than the preset voltage threshold, the alarm circuit breaker is output, the alarm signal is output through the alarm circuit when the alarm circuit breaker is in the opening states, the opening states are greatly monitored by the alarm circuit breaker opening and closing states, and closing states of the circuit breaker opening and closing loops are greatly monitored by the alarm circuit breaker opening and closing the circuit opening and closing states are greatly monitored.
Further, as an implementation of the system shown in fig. 1, an embodiment of the present invention provides a method for monitoring an opening and closing loop of a circuit breaker, where the method includes:
Acquiring a preset voltage threshold value and an auxiliary contact state acquired by a switching value input circuit, wherein the switching value input circuit is connected with an auxiliary contact of a circuit breaker, and the auxiliary contact state is synchronously switched along with switching state conversion of the circuit breaker;
Collecting first voltage values of two 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 with two ends of the normally-closed contact of the circuit breaker in the circuit breaker closing circuit;
Collecting second voltage values of two ends of a normally open contact of a breaker in a breaking loop of the breaker through two input contacts of a second voltage monitoring circuit, wherein the two input contacts of the second voltage monitoring circuit are respectively connected with two ends of the normally open contact of the breaker in the breaking loop of the breaker;
when the circuit breaker is determined to be in a closing state according to the auxiliary contact state, and the first voltage value is smaller than a preset voltage threshold value, the control alarm circuit outputs a closing loop alarm signal in the closing state;
When the breaker is determined to be in a brake-off state according to the auxiliary contact state, and the second voltage value is smaller than the preset voltage threshold value, the control alarm circuit outputs a brake-off loop alarm signal in the brake-off state;
the first voltage monitoring circuit and the second voltage monitoring circuit both comprise high-impedance resistor voltage dividing circuits so as not to influence the operation of the opening and closing loop in the voltage acquisition process.
Further, under the condition that the breaker opening and closing loop is connected into the breaker mechanism tripping prevention loop, the breaker closing loop comprises a newly-added breaker normally-closed contact and a tripping prevention relay normally-closed contact which are connected in series so as to inhibit the tripping position relay and the tripping prevention relay from starting mutually, and before the first voltage values at two ends of the breaker normally-closed contact in the breaker closing loop are collected through two input contacts of the first voltage monitoring circuit, the method further comprises the steps of:
And replacing the normally closed contact of the newly-added breaker and the normally closed contact of the anti-tripping relay which are connected in series in the breaker closing loop with voltage dividing resistors, so that the voltage dividing of the relay for adjusting the opening position and the anti-tripping relay is respectively smaller than the respective starting voltage, and the first voltage monitoring circuit can be conducted.
Further, the switching value input circuit comprises a first switching value input circuit and a second switching value input circuit, the auxiliary contact state comprises a normally closed auxiliary contact state of the circuit breaker and a normally closed auxiliary contact state of the circuit breaker, and the switching state of the circuit breaker is determined according to the auxiliary contact state and comprises the following steps:
acquiring a normally closed auxiliary contact state of the circuit breaker through a first switching value input circuit, and determining that the circuit breaker is in a closing state under the condition that the normally closed auxiliary contact state of the circuit breaker is open;
The normally open auxiliary contact state of the circuit breaker is acquired through the second switching value input circuit, and the circuit breaker is determined to be in a breaking state under the condition that the normally open auxiliary contact state of the circuit breaker is broken.
Further, the alarm circuit comprises a first alarm circuit and a second alarm circuit, wherein output contacts of the first alarm circuit and the second alarm circuit are connected with an output end of a control loop wire breaking circuit so as to output alarm signals in parallel with the control loop wire breaking circuit, the control loop wire breaking circuit comprises a normally closed contact of a switching-on position relay and a normally closed contact of a switching-off position relay which are connected in series, and the control loop wire breaking circuit outputs switching-off loop alarm signals in a switching-on state or switching-off loop alarm signals in a switching-off state according to the state of a circuit breaker under the condition that the normally closed contact of the switching-on position relay and the normally closed contact of the switching-off position relay are closed;
Under the condition that the normally closed auxiliary contact state of the circuit breaker is closed, inhibiting the output of the first alarm circuit so as to output a closing circuit alarm signal in a breaking state through the control circuit breaking circuit;
And under the condition that the normally open auxiliary contact state of the circuit breaker is closed, inhibiting the output of the second alarm circuit so as to output an alarm signal of the opening circuit in the closing state through the control circuit breaking circuit.
Further, the first voltage monitoring circuit comprises a first sampling circuit, a first amplifying circuit and a first analog-to-digital conversion circuit, and the second voltage detecting circuit comprises a second sampling circuit, a second amplifying circuit and a second analog-to-digital conversion circuit;
the first voltage value at two ends of a normally-closed contact of the circuit breaker in the circuit breaker closing loop is collected through two input contacts of a first voltage monitoring circuit, and the circuit breaker closing circuit comprises:
Collecting first voltage analog signals at two ends of a normally-closed contact of a circuit breaker in a circuit breaker closing loop through the first sampling circuit, amplifying the first voltage analog signals through the first amplifying circuit to obtain amplified first voltage analog signals, and converting the amplified first voltage analog signals into digital signals through the first analog-to-digital conversion circuit to obtain first voltage values;
The second voltage value of the two ends of the normally open contact of the breaker in the breaking loop of the breaker is collected through the two input contacts of the second voltage monitoring circuit, and the method comprises the following steps:
And acquiring second voltage analog signals at two ends of a normally open contact of the circuit breaker in the circuit breaker opening loop through the second sampling circuit, amplifying the second voltage analog signals through the second amplifying circuit to obtain amplified second voltage analog signals, and converting the amplified second voltage analog signals into digital signals through the second analog-to-digital conversion circuit to obtain second voltage values.
The embodiment of the invention provides a method for monitoring a breaker opening and closing loop, which is characterized in that a switching value input circuit is connected with an auxiliary contact of a breaker, the auxiliary contact state is acquired through the switching value input circuit, two input contacts of a first voltage monitoring circuit are respectively connected with two ends of a normally closed contact of the breaker in a breaker closing loop, a first voltage value is acquired through the first voltage monitoring circuit, two input contacts of a second voltage monitoring circuit are respectively connected with two ends of a normally open contact of the breaker in the breaker opening and closing loop, a second voltage value is acquired through the second voltage monitoring circuit, a preset voltage threshold value and an auxiliary contact state are acquired through a central control module, a closing loop alarm signal is output through an alarm circuit when the breaker is in the closing state according to the auxiliary contact state, and the alarm signal is output when the first voltage value is smaller than the preset voltage threshold value, the alarm signal is output through the alarm circuit, the opening and closing state of the breaker is monitored by the alarm circuit, and the opening and closing state of the breaker is monitored by the alarm circuit.
It will be appreciated by those skilled in the art that the modules or steps of the invention described above may be implemented in a general purpose computing device, they may be concentrated on a single computing device, or distributed across a network of computing devices, they may alternatively be implemented in program code executable by computing devices, so that they may be stored in a memory device for execution by computing devices, and in some cases, the steps shown or described may be performed in a different order than that shown or described, or they may be separately fabricated into individual integrated circuit modules, or multiple modules or steps within them may be fabricated into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.
The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.