Device for detecting open circuit of current loop of test instrument

Abstract

The invention discloses a test instrument current loop open circuit detection device, and belongs to the technical field of electric power detection. Comprising an input module, a detection assembly and an audible and visual alarm, the detection assembly is composed of a sensing module and an electric signal control module, the sensing module comprises three open-loop Hall sensors, the electric signal control module comprises three optocoupler relays, three groups of independent detection branches are designed in parallel, and the loop current state can be monitored in real time; and when any branch detects an open-circuit fault, sound-light alarm is triggered independently. The input module integrates an alternating current power supply conversion and direct current 24V voltage reduction module, and can be directly connected with an external alternating current power supply and convert the external alternating current power supply into stable working voltage. The fault-tolerant capability of the system is improved through multi-redundancy detection, the response speed is high, the system adapts to various power supply environments, equipment damage and personnel electric shock risks caused by open circuit can be effectively avoided, and the system is suitable for current loop safety monitoring of various electric power test instruments.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power detection, and particularly relates to a test instrument current loop open circuit detection device. BACKGROUND

[0002] In the field of power system testing, as a key element connecting the primary system and the secondary device, the safety of the secondary circuit of the current transformer directly relates to the stability of the testing process and the safety of the operating personnel. When the test instrument needs to be connected to the running current transformer secondary circuit, the traditional operation process needs to connect the test wiring in parallel to the target circuit first, and then disconnect the original secondary circuit to realize the independent work of the test instrument. However, if there is a hidden open circuit fault in the test instrument, at the moment of disconnecting the original secondary circuit, the secondary side of the current transformer will generate thousands of volts or even higher induced high voltage due to the sudden change of magnetic flux. This high voltage not only may break through the internal components of the instrument to cause permanent damage to the device, but also may be conducted to the operating end through the test wiring, posing a serious risk of electric shock to the test personnel.

[0003] In the prior art, the detection of the open circuit of the current loop mainly depends on manual pre-inspection or single node on-off test, which has the following limitations: first, manual detection is low in efficiency, especially in complex test scenarios, which is easy to cause missed detection due to human negligence; second, the traditional detection device mainly adopts a series single sensor structure, and if the sensor itself fails or the signal transmission is interrupted, the whole detection system will be directly disabled, forming a "blind area" of detection; third, the response speed of some detection schemes is slow, which cannot complete fault judgment within a short time before the secondary circuit is disconnected, and it is difficult to meet the real-time protection requirements.

[0004] With the development of smart grid technology, test instruments are evolving towards high precision and miniaturization, which puts higher requirements on the real-time performance and reliability of the current loop state monitoring. Under this background, it is a key technical requirement to develop a detection device that can quickly identify internal open circuit faults of the instrument before test wiring switching, has multiple redundant detection capabilities, and is suitable for various power supply environments to ensure the safety of power testing. SUMMARY

[0005] The application provides a test instrument current loop open circuit detection device, which realizes fast response and multiple protection when a current loop open circuit fault occurs through the synergistic effect of a multi-path parallel detection circuit and an audible and visual alarm module, and solves the problems of low detection efficiency, poor reliability and slow response in the prior art.

[0006] To achieve the above purpose, the application provides a test instrument current loop open circuit detection device, which comprises an input module, a detection component and an audible and visual alarm.

[0007] The input module is electrically connected to the detection module, and the detection component is used to detect the electrical signal of the circuit under test. The audible and visual alarm is electrically connected to the detection component and is used to issue an alarm signal when an open circuit in the current loop is detected.

[0008] The detection module includes a sensing module and an electrical signal control module. The sensing module is used to sense the current change in the circuit under test and transmit the sensing signal to the electrical signal control module for processing. The electrical signal control module is electrically connected in series with the audible and visual alarm. The electrical signal control module determines whether there is an open circuit fault based on the sensing signal. When an open circuit fault is determined, the electrical signal control module triggers the audible and visual alarm to issue an alarm signal.

[0009] In one embodiment, the sensing module includes open-loop Hall sensor H1, open-loop Hall sensor H2, and open-loop Hall sensor H3. The signal output terminals OUT of the open-loop Hall sensors H1, H2, and H3 are connected in series with the electrical signal control module to transmit the detection signal to the electrical signal control module. The electrical signal control module analyzes the detection signals of the three Hall sensors to determine whether there is a current breakpoint in the circuit under test. The current input terminals of the open-loop Hall sensors H1, H2, and H3 are connected to the input module.

[0010] In one embodiment, the electrical signal control module includes optocoupler relays G1, G2, and G3. The input terminals V of optocoupler relays G1, G2, and G3 are respectively connected to the signal output terminals OUT of open-loop Hall sensors H1, H2, and H3, and the NO terminal is connected to the input module. The normally closed contact terminals NC and CO of optocoupler relays G1, G2, and G3 are connected in series and then connected to the audible and visual alarm.

[0011] In one embodiment, the open-loop Hall sensor H1 and optocoupler relay G1, the open-loop Hall sensor H2 and optocoupler relay G2, and the open-loop Hall sensor H3 and optocoupler relay G3 are connected in parallel in the circuit to form three independent detection branches. Each branch can independently determine the current loop status. When any branch detects an abnormal current disconnection, the corresponding optocoupler relay outputs a trigger signal, which forms a complete alarm loop through the series-connected audible and visual alarm.

[0012] In one embodiment, the input module includes a 24V DC step-down module. The negative output terminal -V1 of the 24V DC step-down module is connected in parallel with three branches, which are respectively connected to the power supply terminals V of open-loop Hall sensors H1, H2, and H3. The positive output terminal +V1 of the 24V DC step-down module is electrically connected to optocoupler relays G1, G2, and G3.

[0013] In one embodiment, the input module further includes an AC power conversion module for converting the input AC power into DC 24V power.

[0014] In one embodiment, the input L terminal and N terminal of the AC power conversion module are connected to an external AC power source, and the output positive terminal +V1 and output negative terminal -V1 are respectively connected to the input positive terminal +V0 and input negative terminal -V0 of the DC 24V step-down module.

[0015] In one embodiment, the positive output terminal +V2 of the AC power conversion module is connected in parallel to three branches, which are respectively connected to the CO terminals of three sets of parallel optocoupler relays G1, G2 and G3. The CO terminal is connected to the N0 terminal through a contact switch, and the N0 terminal is connected to the audible and visual alarm.

[0016] In one embodiment, the NO terminals of optocoupler relays G1, G2, and G3 are respectively connected to the first input signal terminal, the second input signal terminal, and the third input signal terminal of the audible and visual alarm.

[0017] In one embodiment, the positive terminal of the power supply of the audible and visual alarm is connected to the positive output terminal +V2 of the AC power conversion module, and the negative terminal of the power supply is connected in series with the common input terminal and then connected to the negative output terminal -V2 of the AC power conversion module to form a loop.

[0018] Compared with the prior art, the beneficial effects of this application are:

[0019] 1. Through the parallel design of three independent detection branches, each branch consists of an open-loop Hall sensor and an optocoupler relay to form an independent judgment unit, which can monitor the current status of different circuits in real time. When any branch detects an open circuit fault, it can independently trigger an alarm, effectively avoiding the problem of missed detection caused by single-point faults and improving the reliability and fault tolerance of the detection system.

[0020] 2. The current loop is connected in series to the test instrument through this device. The device detects the current in the loop through an internally installed open-loop Hall current sensor. When the current detected by the open-loop Hall current sensor is greater than the zero drift current, the output voltage causes the optocoupler relay to operate. The normally closed auxiliary node of the optocoupler relay is connected in series with the audible and visual alarm on the device, which disconnects its circuit and prevents the alarm signal from being triggered.

[0021] When the device detects an open circuit in the current loop, the optocoupler relay does not trip, the audible and visual alarm circuit is activated, and the device issues an audible and visual alarm. When the device detects a normal current loop, the optocoupler relay trips, the audible and visual alarm circuit is deactivated, and the device does not issue an audible or visual alarm. This serves as a reminder to the testing personnel that an open circuit exists in the current loop of the testing instrument, and that the secondary circuit connected in parallel with it must not be disconnected, thus preventing personal injury or equipment damage caused by an open current loop. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Fig. 1 A schematic diagram of the overall test instrument current loop open circuit detection device provided in this application; Fig. 2 Internal diagram of the current loop open circuit detection device for the test instrument provided in this application; Fig. 3 A schematic diagram of the drive mechanism of the test instrument current loop open circuit detection device provided in this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0028] See Figs. 1 to 3 As shown, the test instrument current loop open circuit detection device provided in this application includes an input module, a detection component, and an audible and visual alarm. The input module is electrically connected to the detection module, and the detection component is used to detect the electrical signal of the circuit under test. The audible and visual alarm is electrically connected to the detection component and is used to issue an alarm signal when an open circuit in the current loop is detected.

[0029] The input module is electrically connected to the detection module, and the detection component is used to detect the electrical signal of the circuit under test. The audible and visual alarm is electrically connected to the detection component and is used to issue an alarm signal when an open circuit in the current loop is detected.

[0030] The testing process is as follows: After the input module is connected to the circuit under test, the detection component monitors the current changes in the circuit in real time. If the detected current value is lower than the set threshold, it is determined that the current loop is open. At this time, the audible and visual alarm is immediately activated, prompting the operator to check and handle the situation through flashing lights and a buzzer. When the current in the circuit is within the normal range, the detection component will remain silent, and the audible and visual alarm will not be triggered, thus ensuring the continuity and safety of the test process.

[0031] The detection module includes a sensing module and an electrical signal control module. The sensing module is used to sense the current change in the circuit under test and transmit the sensing signal to the electrical signal control module for processing. The electrical signal control module is electrically connected in series with the audible and visual alarm. The electrical signal control module determines whether there is an open circuit fault based on the sensing signal. When an open circuit fault is determined, the electrical signal control module triggers the audible and visual alarm to issue an alarm signal.

[0032] After the circuit under test is connected to the input module, the sensing module will capture the current signal and transmit it to the processing unit. The processing unit will make a judgment based on the preset threshold. If the detected current value is lower than the set threshold, it will be judged that the current loop is in an open circuit state. At the same time, the electrical signal control module will trigger the sound and light alarm to start and issue an alarm signal to remind the operator to check and handle the problem.

[0033] Optionally, the sensing module includes open-loop Hall sensor H1, open-loop Hall sensor H2, and open-loop Hall sensor H3. The signal output terminals OUT of open-loop Hall sensor H1, open-loop Hall sensor H2, and open-loop Hall sensor H3 are connected in series with the electrical signal control module to transmit the detection signal to the electrical signal control module. The electrical signal control module analyzes the detection signals of the three Hall sensors to determine whether there is a current break in the circuit under test. The current input terminals of open-loop Hall sensor H1, open-loop Hall sensor H2, and open-loop Hall sensor H3 are connected to the input module.

[0034] In this embodiment, an open-loop Hall sensor detects changes in current in the loop. The open-loop Hall sensor senses the current signal and generates a corresponding voltage signal, which is then transmitted to the electrical signal control module. The electrical signal control module determines the current state based on the voltage signal.

[0035] If the open-loop Hall sensor detects that the current in the circuit is greater than the zero-drift current, it outputs a voltage signal to drive the optocoupler relay to open its normally closed node, thereby cutting off the audible and visual alarm circuit and stopping the alarm. If the open-loop Hall sensor detects that the current circuit is open, the corresponding electrical signal control module does not receive a valid current signal, so the optocoupler relay does not operate, the audible and visual alarm circuit remains conductive, and the audible and visual alarm continues to sound. When all open-loop Hall sensors detect that the current circuit is normal, their output voltage signals drive the corresponding electrical signal control modules to operate, causing the power supply circuits of all audible and visual alarms to be disconnected. At this time, the entire system is in a no-alarm state, ensuring that the test operators can continue to carry out relevant work in a safe environment.

[0036] In this way, the system can issue an alarm in a timely manner when an abnormality occurs in the current circuit, reminding operators to take immediate measures to prevent the fault from escalating and to ensure the safety of equipment and personnel.

[0037] Optionally, the electrical signal control module includes optocoupler relays G1, G2, and G3. The input terminals V of the optocoupler relays G1, G2, and G3 are respectively connected to the signal output terminals OUT of the open-loop Hall sensors H1, H2, and H3, and the NO terminal is connected to the input module. The normally closed contact terminals NC and CO of the optocoupler relays G1, G2, and G3 are connected in series and then connected to the audible and visual alarm.

[0038] In this implementation, open-loop Hall sensors H1, H2, and H3 detect their respective current loops. When an abnormal current occurs in any loop, the corresponding Hall sensor outputs a voltage signal, driving the corresponding optocoupler relay to open its normally closed contact NC and CO, while simultaneously closing its normally open contact NO and CO, thus changing the on / off state of the audible and visual alarm circuit. When any optocoupler relay activates, its normally open contact NO and CO close, causing the audible and visual alarm circuit to conduct, and the alarm to activate, emitting an audible and visual warning. Through the design of multiple independent detection branches, the system can accurately identify the operating status of each current loop, ensuring timely alarm in case of any loop abnormality, thus improving overall safety and reliability.

[0039] Optionally, the open-loop Hall sensor H1 and optocoupler relay G1, the open-loop Hall sensor H2 and optocoupler relay G2, and the open-loop Hall sensor H3 and optocoupler relay G3 are connected in parallel in the circuit to form three independent detection branches. Each branch can independently determine the current loop status. When any branch detects an abnormal current disconnection, the corresponding optocoupler relay outputs a trigger signal, which forms a complete alarm loop through the series-connected audible and visual alarm.

[0040] In this embodiment, by connecting them in parallel, when an abnormal current occurs in any loop, the corresponding Hall sensor will output a voltage signal, driving the corresponding optocoupler relay to open its normally closed contact. This changes the on / off state of the audible and visual alarm circuit, turning it on and triggering the alarm to emit an audible and visual warning. Through the design of multiple independent detection branches, the system can accurately identify the operating status of each current loop, ensuring timely alarm in case of any loop abnormality, thus improving overall safety and reliability.

[0041] Optionally, the input module includes a 24V DC step-down module. The negative output terminal -V1 of the 24V DC step-down module is connected in parallel with three branches, which are respectively connected to the power supply terminals V of open-loop Hall sensors H1, H2, and H3. The positive output terminal +V1 of the 24V DC step-down module is electrically connected to optocoupler relays G1, G2, and G3.

[0042] In this embodiment, a 24V DC step-down module generates a stable 5V power supply to provide operating voltage for each open-loop Hall current sensor and optocoupler relay, ensuring that each sensor operates stably within its rated range and avoiding false alarms or missed alarms due to voltage fluctuations.

[0043] Optionally, the input module may also include an AC power conversion module, which converts the input AC power into DC 24V power.

[0044] Optionally, the input L and N terminals of the AC power conversion module are connected to an external AC power source, and the output positive +V1 terminal and output negative -V1 terminal are respectively connected to the input positive +V0 terminal and input negative -V0 terminal of the DC 24V step-down module.

[0045] It should be noted that a power switch QF1 is connected in series between the input L and N terminals of the AC power conversion module and the external AC power supply. Power switch QF1 controls the power supply to the entire circuit, allowing operators to quickly disconnect the power supply during equipment maintenance or emergencies, ensuring safety. Furthermore, power switch QF1 adopts a circuit breaker structure, possessing overload and short-circuit protection functions, and can automatically trip in case of circuit abnormalities to prevent the fault from escalating.

[0046] Optionally, the input L and N terminals of the AC power conversion module are connected to an external AC power source, and the output positive +V1 terminal and output negative -V1 terminal are respectively connected to the input positive +V0 terminal and input negative -V0 terminal of the DC 24V step-down module.

[0047] In this embodiment, the AC power converter converts the external detection voltage to DC 24V, providing a stable operating voltage for the entire system. One path of the DC 24V power supply powers the audible and visual alarm circuit, while the other path is converted to 5V via a DC step-down module, specifically for powering each open-loop Hall current sensor.

[0048] Optionally, the NO terminals of optocoupler relays G1, G2, and G3 are connected to the first input signal terminal, the second input signal terminal, and the third input signal terminal of the audible and visual alarm, respectively.

[0049] In this implementation, the optocoupler relays of different branch detection circuits are independently connected to the signal terminals of the audible and visual alarm to ensure that abnormal signals of each branch can independently trigger the alarm mechanism and avoid mutual interference.

[0050] Optionally, the positive terminal of the power supply of the audible and visual alarm is connected to the positive output terminal +V2 of the AC power conversion module, and the negative terminal of the power supply is connected in series with the input common terminal and then connected to the negative output terminal -V2 of the AC power conversion module to form a circuit. The audible and visual alarm is powered by the AC power conversion module, and the normally closed contacts of each optocoupler relay are connected in series to form a complete circuit. When the current in any branch is abnormal, the normally closed contact of the optocoupler relay opens, causing the audible and visual alarm circuit to conduct, thereby triggering the corresponding audible and visual alarm and realizing rapid location and indication of the fault point.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A current loop open circuit detection device for a testing instrument, characterized in that: Includes an input module, detection components, and an audible and visual alarm; The input module is electrically connected to the detection module, and the detection component is used to detect the electrical signal of the circuit under test; the audible and visual alarm is electrically connected to the detection component and is used to issue an alarm signal when an open circuit in the current loop is detected. The detection module includes a sensing module and an electrical signal control module. The sensing module is used to sense the current change in the circuit under test and transmit the sensing signal to the electrical signal control module for processing. The electrical signal control module is electrically connected in series with the audible and visual alarm. The electrical signal control module determines whether there is an open circuit fault based on the sensing signal. When an open circuit fault is determined to exist, the electrical signal control module triggers the audible and visual alarm to issue an alarm signal.

2. The test instrument current loop open circuit detection device according to claim 1, characterized in that: The sensing module includes open-loop Hall sensor H1, open-loop Hall sensor H2, and open-loop Hall sensor H3. The signal output terminals OUT of the open-loop Hall sensors H1, H2, and H3 are connected in series with the electrical signal control module to transmit the detection signal. The electrical signal control module analyzes the detection signals from the three Hall sensors to determine whether there is a current break in the circuit under test. The current input terminals of the open-loop Hall sensors H1, H2, and H3 are connected to the input module.

3. The test instrument current loop open circuit detection device according to claim 2, characterized in that: The electrical signal control module includes optocoupler relays G1, G2, and G3. The input terminals V of the optocoupler relays G1, G2, and G3 are respectively connected to the signal output terminals OUT of the open-loop Hall sensors H1, H2, and H3, and the NO terminal is connected to the input module. The normally closed contact terminals NC and CO of the optocoupler relays G1, G2, and G3 are connected in series and then connected to the audible and visual alarm.

4. The test instrument current loop open circuit detection device according to claim 3, characterized in that: The open-loop Hall sensor H1 and the optocoupler relay G1, the open-loop Hall sensor H2 and the optocoupler relay G2, and the open-loop Hall sensor H3 and the optocoupler relay G3 are connected in parallel in the circuit, forming three independent detection branches. Each branch can independently determine the current loop status. When any branch detects an abnormal current disconnection, the corresponding optocoupler relay outputs a trigger signal, which forms a complete alarm loop through the series-connected audible and visual alarm.

5. The test instrument current loop open circuit detection device according to claim 3, characterized in that: The input module includes a 24V DC step-down module. The negative output terminal -V1 of the 24V DC step-down module is connected in parallel with three branches, which are respectively connected to the power supply terminals V of the open-loop Hall sensors H1, H2, and H3. The positive output terminal +V1 of the 24V DC step-down module is electrically connected to the optocoupler relays G1, G2, and G3.

6. The test instrument current loop open circuit detection device according to claim 5, characterized in that: The input module also includes an AC power conversion module, which is used to convert the input AC power into DC 24V power.

7. The test instrument current loop open circuit detection device according to claim 6, characterized in that: The input L and N terminals of the AC power conversion module are connected to an external AC power source, and the output positive +V1 and output negative -V1 terminals are respectively connected to the input positive +V0 and input negative -V0 terminals of the DC 24V step-down module.

8. The test instrument current loop open circuit detection device according to claim 6, characterized in that: The input L and N terminals of the AC power conversion module are connected to an external AC power source, and the output positive +V1 and output negative -V1 terminals are respectively connected to the input positive +V0 and input negative -V0 terminals of the DC 24V step-down module.

9. The test instrument current loop open circuit detection device according to claim 8, characterized in that: The NO terminals of the optocoupler relays G1, G2, and G3 are respectively connected to the first input signal terminal, the second input signal terminal, and the third input signal terminal of the audible and visual alarm.

10. The test instrument current loop open circuit detection device according to claim 9, characterized in that: The positive terminal of the power supply of the audible and visual alarm is connected to the positive output terminal +V2 of the AC power conversion module, and the negative terminal of the power supply is connected in series with the input common terminal and then connected to the negative output terminal -V2 of the AC power conversion module to form a loop.

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