Meter box opening detection method under power failure condition of electric energy meter

Abstract

The invention provides a meter box opening detection method under the condition of power failure of an electric energy meter. The meter box opening detection method under the power failure condition of the electric energy meter comprises four steps of a preparation stage, power-on detection, power-off detection and maintenance and processing, through setting a charging circuit composed of a resistor R168 and a super capacitor SC1, the method can carry out detection when a meter box is power-off, and it is ensured that the meter box is not powered off even under the power failure condition of a power grid. According to the meter box opening detection method under the power failure condition of the electric energy meter provided by the invention, the super capacitor SC1 is introduced as a temporary power supply, and electric energy can be provided for a weak current interface side when a power grid is powered off, so that the normal work of a detection circuit is ensured, and the stability of a system is enhanced; the situation of detection function failure caused by power failure is reduced, the detection reliability of the electric energy meter under the power failure condition is improved, and the behavior that a user opens the meter box to conduct electricity stealing modification under the power failure state is effectively prevented.

Description

Technical Field

[0001] The invention relates to the technical field of electronic equipment, and in particular to a method for detecting an open meter box when an electric energy meter is out of power. Background Art

[0002] The energy meter, also known as the watt-hour meter, fire meter, kilowatt-hour meter, is an instrument used to measure electrical energy. It is an instrument for measuring various electrical quantities, capable of recording the electrical energy consumed over a period of time, and is an important component of the power system. The working principle of the energy meter is mainly divided into two types: electrical mechanical and electronic. The electrical mechanical energy meter measures electrical energy through a mechanical structure, while the electronic energy meter uses electronic technology and integrated circuits for measurement. The energy meter plays an important role in the power system, not only for power metering and electricity bill settlement, but also for providing parameters such as power load and power factor, providing an important basis for the operation and management of the power system.

[0003] Opening the meter box is the act or process of opening the box or casing used to install the electricity meter. The main function of the meter box is to protect the electricity meter from interference and damage from the external environment while providing a safe electrical connection. Under normal circumstances, the meter box is locked to prevent unauthorized access and potential electrical hazards. However, in some cases, such as when inspecting, repairing or replacing the electricity meter, it is necessary to open the meter box to access the electricity meter.

[0004] The schematic diagram of the existing open meter box detection function is as attached to the manual. Figure 2 As shown, the detection principle is: when the meter box cover is covered, the switch of JP631 is in an open circuit state, at this time the optocoupler E470 is not conducting, the BOX CHK pin is pulled up by R471, the BOXCHK pin level is high, and the electric energy meter determines that the meter box is closed; when the meter box cover is opened, the switch of JP631 is in a closed state, at this time the optocoupler E470 is conducting, the BOX_CHK pin is pulled down, the BOX CHK pin level is low, and the electric energy meter determines that the meter box is opened.

[0005] It has been found that the existing meter box opening detection function is still insufficient. First of all, the meter box opening detection interface belongs to the weak current interface, and a 4KV insulation test is required with the metering system. Therefore, the weak current interface and the metering system are isolated by an optocoupler, and the two sides are powered by different power circuits. In general, in order to maintain the clock and cover opening detection in a power outage state, the metering system will be equipped with a lithium battery on the metering system side, while there is no backup power supply on the weak current interface side. When the power grid is out of power, there is no power on the weak current interface side, which makes the detection circuit on the weak current side unable to work normally. At this time, the meter box opening detection function is invalid. If the user opens the meter box and makes electricity theft modifications when the power grid is out of power, the electric energy meter cannot record the electricity theft event. Therefore, the existing meter box opening detection function causes inconvenience in actual use.

[0006] Therefore, it is necessary to provide a new method for detecting the opening of the meter box when the electric energy meter is out of power to solve the above technical problems. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a method for detecting an open meter box when an electric energy meter is out of power.

[0008] The method for detecting the opening of the meter box of the electric energy meter under the condition of power failure provided by the present invention has the following operating steps:

[0009] Step 1, preparation stage: ensure that necessary tools such as voltmeter or multimeter, insulated screwdriver, test clip, etc. are complete and in good working condition. Wear appropriate protective equipment, such as insulating gloves and goggles, to ensure safety during operation. Use a voltmeter or multimeter to measure the voltage of the power grid. Connect the test clip to the phase line and neutral line of the power grid, read the voltage value, and confirm whether the current power grid has power. If the power grid has power, proceed to step 2. If the power grid is out of power, skip step 2 and proceed to step 3.

[0010] Step 2, power detection: When the grid has power, use a multimeter to connect the test clips to the two pins of the upper diode of diode D7, set the multimeter to diode test mode, check whether the upper diode of diode D7 is turned on, use a multimeter to connect the test clips to both ends of resistor R168, read the resistance value of resistor R168, and confirm whether it is within the design range. If the resistance value is abnormal, it means that the resistor is damaged. After detecting resistor R168, disconnect the supercapacitor SC1 and use a multimeter to measure its capacitance. If both resistor R168 and supercapacitor SC1 are normal, connect the circuit again and observe whether supercapacitor SC1 can be charged normally. Confirm whether the charging circuit works normally by measuring the voltage change at both ends of supercapacitor SC1. Detect whether the charging circuit composed of resistor R168 and the established supercapacitor SC1 works normally. Use a multimeter to connect the test clips to the BOX CHK pin and the reference ground, read the level status, and confirm whether it is within the normal range. If the BOX CHK pin level does not jump, it means that the meter box is open normally. If BOX If the level of the CHK pin changes, record the situation and jump to step 4 to determine whether the meter box is in a normal state based on the test results;

[0011] It should be noted that the forward resistance of a diode is small, ranging from a few ohms to tens of ohms, and the reverse resistance is large, ranging from a few thousand ohms to infinity;

[0012] Step 3: No-power detection: When there is no power in the grid, use a multimeter to connect the test clip to the two pins of diode VD2 respectively, set the multimeter to diode test mode, check whether diode VD2 is turned on, and if diode VD2 is turned on, confirm that supercapacitor SC1 can supply power to the left optocoupler circuit through VD2. Use a multimeter to connect the test clip to BOX CHK pin and reference ground, read the level state of BOX CHK pin at this time, and judge whether the level of BOX CHK pin changes. According to the test results, judge whether the meter box is in normal state;

[0013] Step 4: Repair and treatment: The repair and treatment includes the following stages:

[0014] Phase 1: Troubleshooting and recording phase: According to the abnormal conditions recorded in the power-on and power-off detection, the cause of the circuit abnormality is investigated;

[0015] Phase 2: Replace or repair faulty components: Replace damaged components based on the results of the investigation, and re-weld or tighten the connection points for poor connections;

[0016] Phase 3, functional test phase: After replacing or repairing the faulty component, re-perform the functional test, repeat the power-on or power-off detection process, and observe the conduction of diode D7 or VD2 and the level status of the BOX CHK pin again to ensure that the meter box can work normally with or without power, and the level status of the BOX CHK pin is correct.

[0017] Stage 4: Recording and feedback stage: Record all operations, inspection results and test results during the maintenance process and provide feedback to relevant departments;

[0018] Stage 5: Power supply restoration stage: After the functional test shows normal results and the records are completed, restore the power supply and observe the operation of the meter box.

[0019] Preferably, the step 2 includes the following steps:

[0020] S1. If the upper diode of diode D7 is turned on, F5V charges supercapacitor SC1 through the lower diode of D7 and resistor R168, and then proceeds to step S2. If the upper diode of diode D7 is not turned on, F5V power supply cannot supply power to the left optocoupler circuit. This situation is recorded and the process goes to step 4.

[0021] S2, judging the charging circuit composed of the resistor R168 and the established super capacitor SC1, if the charging circuit works normally, executing step S3, if the charging circuit does not work normally, checking whether the resistor R168 is damaged, recording the situation, and jumping to step 4;

[0022] S3. Measure the level status of the BOX CHK pin. If the BOX CHK pin level does not jump, it means that the meter box is open normally. If the BOX CHK pin level changes, jump to step 4.

[0023] Preferably, in step three, the following steps are included:

[0024] Step 1: When diode VD2 is turned on, continue to execute Step 2;

[0025] Step 2. Observe the level status of the BOX CHK pin. If the BOX CHK pin level remains stable, it means that the meter box is open normally. The super capacitor SC1 supplies power to the left optocoupler circuit through the diode VD2, so that the meter opening detection circuit works normally in the power outage state of the power grid. Execute step 2. If the BOX CHK pin level changes, record the situation and execute step 3.

[0026] Step 3. According to the change of BOX CHK pin level, confirm whether the meter box is opened. When the BOX CHK pin level changes, it indicates that the meter box is opened, triggering the alarm function of the energy meter, the buzzer sounds, the indicator light flashes, and the situation is recorded at the same time, and jump to step 4.

[0027] It should be noted that, in the detection of power outages in the power grid, if the diode VD2 is not conducting, it is generally not taken into consideration because VD2 is a backup power supply path.

[0028] Preferably, in the electrical detection of step 2, a multimeter is used to measure the voltage drop across resistor R168 to confirm whether it is within a normal range. If the voltage drop is too large or too small, it indicates that the resistance value of R168 is abnormal.

[0029] Preferably, in step 2 and step 3, it is also necessary to confirm in advance whether all connection points are firm and free of looseness or corrosion.

[0030] Preferably, in the step 2 of power detection, it also includes measuring the voltage across the supercapacitor SC1 and confirming whether it is gradually rising and approaching the voltage value of F5V. If the voltage of the supercapacitor SC1 rises slowly or does not rise, it indicates that there is a problem with the charging circuit.

[0031] Preferably, in the step 3 of the power-off detection, if the diode VD2 is not conducting, this situation is recorded, and the recorded data is: the super capacitor SC1 cannot be discharged or the diode VD2 is damaged.

[0032] Preferably, in the first stage, troubleshooting includes checking whether the diodes D7 and VD2 are damaged or poorly connected, checking whether the resistor R168 is damaged or has a changed resistance, and checking whether the supercapacitor SC1 has leakage or a decreased capacity.

[0033] Preferably, in the first stage, troubleshooting further includes using a multimeter to detect abnormal components.

[0034] Compared with the related art, the method for detecting the opening of the meter box in the case of power outage of the electric energy meter provided by the present invention has the following beneficial effects:

[0035] 1. This method introduces supercapacitor SC1 as a temporary power source to provide power to the weak current interface side when the power grid is out of power, thereby ensuring the normal operation of the detection circuit, enhancing the stability of the system, and reducing the failure of the detection function caused by power outages;

[0036] 2. This method can be used to detect when the meter box is without electricity, ensuring that the meter box detection function can work normally even when the power grid is out, improving the reliability of detection and effectively preventing users from opening the meter box to steal electricity during a power outage;

[0037] 3. This method solves the problem that the detection circuit cannot work normally when the power grid is out of power. During the short period of power outage, the supercapacitor SC1 can provide sufficient power for the detection circuit so that it can continue to work normally and record the status of the open meter box, reducing the failure of the detection function due to power outages and improving the reliability and stability of the system. The supercapacitor SC1 used has the characteristics of long cycle life and fast charging and discharging. The supercapacitor SC1 can remain stable during multiple power outages and power restoration, and will not be damaged due to frequent charging and discharging, ensuring the long-term normal operation of the open meter box detection function. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A flowchart of the overall process of the method for detecting the opening of the meter box when the electric energy meter is out of power provided by the present invention;

[0039] Figure 2 The principle diagram of the existing meter box opening detection function mentioned in the background technology;

[0040] Figure 3 This is the schematic diagram of the improved meter box opening detection function;

[0041] Figure 4 This is a flowchart of power detection;

[0042] Figure 5 This is a flowchart of power-off detection. DETAILED DESCRIPTION

[0043] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0044] Please refer to Figures 1 to 5 ,in, Figure 1 A flowchart of the overall process of the method for detecting the opening of the meter box when the electric energy meter is out of power provided by the present invention; Figure 2 The principle diagram of the existing meter box opening detection function mentioned in the background technology; Figure 3 This is the schematic diagram of the improved meter box opening detection function; Figure 4 This is a flowchart of power detection; Figure 5 This is a flowchart of power-off detection.

[0045] Embodiment 1

[0046] In the specific implementation process, Figures 1 to 5 As shown, the following operation steps are included: Step 1, preparation stage: before opening the meter box for detection, ensure that the necessary tools such as voltmeter or multimeter, insulated screwdriver, test clip, etc. are complete and in good working condition, wear insulating gloves and goggles to ensure safety during operation, use a voltmeter or multimeter to measure the voltage of the power grid, connect the test clip to the phase line and neutral line of the power grid, read the voltage value, and confirm whether the current power grid has electricity. If the power grid has electricity, execute step 2. If the power grid is out of power, skip step 2 and execute step 3;

[0047] It should be noted that the grid voltage is determined by the local standard, which is 220V or 380V;

[0048] Step 2, power detection: When the grid has electricity, use the grid power supply, use a multimeter, connect the test clips to the two pins of the upper diode of diode D7 respectively, set the multimeter to diode test mode, check whether the upper diode of diode D7 is turned on, then use the multimeter to connect the test clips to both ends of resistor R168 respectively, read the resistance value of resistor R168, and confirm whether it is within the design range. If the resistance value is abnormal, it means that the resistor is damaged. After detecting resistor R168, disconnect the supercapacitor SC1 at this time, and use a multimeter to measure its capacitance value. If both resistor R168 and supercapacitor SC1 are normal, connect the circuit again, observe whether supercapacitor SC1 can be charged normally, and confirm whether the charging circuit works normally by measuring the voltage change at both ends of supercapacitor SC1. Detect whether the charging circuit composed of resistor R168 and the established supercapacitor SC1 works normally. Use a multimeter to connect the test clip to the BOX CHK pin and the reference ground, read the level status, and confirm whether it is within the normal range. If BOX If the CHK pin level does not jump, it means that the meter box is open normally. If the BOXCHK pin level changes, record the situation and jump to step 4 to determine whether the meter box is open normally based on the test results.

[0049] It should be noted that the forward resistance of a diode is small, ranging from a few ohms to tens of ohms, and the reverse resistance is large, ranging from a few thousand ohms to infinity;

[0050] It should be noted that when the grid has electricity, the grid is used to supply power to detect whether the upper diode of diode D7 is turned on in order to check whether the power supply on the weak current interface side is normal;

[0051] It should be noted that, in the power-on detection, if the BOX CHK pin level is high, the meter box is closed; if the level is low, the meter box is opened.

[0052] Step 3: No-power detection: When the grid is without power, since there is no backup power supply on the weak current interface side, it is necessary to observe whether the diode VD2 is turned on. First, use a multimeter to connect the test clip to the two pins of the diode VD2 respectively, set the multimeter to the diode test mode, and check whether the diode VD2 is turned on. If the diode VD2 is turned on, it is confirmed that the supercapacitor SC1 can supply power to the left optocoupler circuit through the diode VD2. Use a multimeter to connect the test clip to the BOX CHK pin and the reference ground, read the level state of the BOX CHK pin at this time, and determine whether the BOX CHK pin level changes. According to the test results, determine whether the meter box is in a normal state;

[0053] It should be noted that the diode VD2 is powered by the supercapacitor SC1 on the metering system side, so it can work normally even when the power grid is out of power. The conduction state of VD2 can be used to determine whether the supercapacitor SC1 is supplying power normally.

[0054] Step 4: Repair and treatment: The repair and treatment includes the following stages:

[0055] Phase 1: Troubleshooting and recording phase: According to the abnormal conditions recorded in the power-on and power-off detection, the cause of the circuit abnormality is investigated;

[0056] Phase 2: Replace or repair faulty components: Replace damaged components based on the results of the investigation, and re-weld or tighten the connection points for poor connections;

[0057] Phase 3, functional test phase: After replacing or repairing the faulty component, re-perform the functional test, repeat the power-on or power-off detection process, and observe the conduction of diode D7 or VD2 and the level status of the BOX CHK pin again to ensure that the meter box can work normally with or without power, and the level status of the BOX CHK pin is correct.

[0058] Stage 4: Recording and feedback stage: Record all operations, inspection results and test results during the maintenance process and provide feedback to relevant departments;

[0059] Stage 5: Power supply restoration stage: After the functional test shows normal results and the records are completed, restore the power supply and observe the operation of the meter box.

[0060] In the first stage, the troubleshooting includes checking whether the diodes D7 and VD2 are damaged or poorly connected, checking whether the resistor R168 is damaged or has a changed resistance, and checking whether the supercapacitor SC1 is leaking or has a reduced capacity.

[0061] In the first stage, troubleshooting also includes using a multimeter to detect abnormal components.

[0062] It should be noted that through detailed troubleshooting and connection point inspection, the integrity and reliability of the circuit can be ensured during the detection process, thereby improving the accuracy of the detection results. By measuring the voltage drop of resistor R168 and the voltage of supercapacitor SC1, faults in the circuit can be discovered in time, such as abnormal resistance, supercapacitor leakage or capacity reduction, so that timely measures can be taken to deal with them and avoid the expansion of the fault or affecting the normal operation of the electric energy meter.

[0063] It should be noted that by introducing supercapacitor SC1 as a temporary power supply, it can provide power to the weak current interface side when the power grid is out of power, thereby ensuring the normal operation of the detection circuit, enhancing the stability of the system, and reducing the failure of the detection function caused by power outages.

[0064] refer to Figure 1 , Figure 3 as well as Figure 4 As shown, in the step 2, the following steps are included:

[0065] S1. If the upper diode of diode D7 is turned on, F5V charges supercapacitor SC1 through the lower diode of D7 and resistor R168, and then proceed to step S2. If the upper diode of diode D7 is not turned on, F5V power supply cannot supply power to the left optocoupler circuit. This abnormality is recorded, and the process directly jumps to step 4 for maintenance and processing. Among them, F5V is a 5V DC power supply.

[0066] S2. After confirming that the F5V power supply can charge the supercapacitor SC1 normally, the charging circuit composed of the resistor R168 and the established supercapacitor SC1 is judged. If the charging circuit works normally, that is, the supercapacitor SC1 can stably receive and store electrical energy, then continue to execute step S3. If the charging circuit does not work normally, check whether the resistor R168 is damaged, record the situation, and jump to step 4.

[0067] S3. After confirming that the charging circuit is working properly, start monitoring the level status of the BOX CHK pin. If the BOX CHK pin level does not jump, it means that the meter box is open normally. If the BOX CHK pin level changes, jump to step 4.

[0068] It should be noted that the BOX CHK pin is the key signal input point of the meter box open detection function, and its level status directly reflects the status of the meter box open. If the BOX CHK pin level does not jump, that is, it remains in a high level state, high level state: 5V or close to 5V, it means that the meter box is in a normal closed state; if the BOX CHK pin level changes, that is, from a high level state to a low level state, low level state: 0V or close to 0V, it means that the meter box has been opened or there is an abnormal situation. At this time, record the abnormal change and jump to step 4 for further maintenance and processing.

[0069] It should be noted that, when executing step S3, in addition to directly monitoring the level state of the BOX CHK pin, other relevant factors can also be considered comprehensively, as follows:

[0070] The process includes checking the state of the optocoupler E470: observing whether the light emitting diode (LED) of the optocoupler E470 is emitting light;

[0071] If the LED lights up, it means that there is current flowing through the input end of the optocoupler E470. At this time, the JP631 switch is in the closed state or there are other abnormal conditions that cause the optocoupler to turn on.

[0072] If the LED does not light up, it means that no current flows through the input end of the optocoupler E470. At this time, the JP631 switch is in an open circuit state or the optocoupler itself is damaged.

[0073] This includes verifying the switch status of JP631: inferring the actual switch status of JP631 based on the status of the optocoupler E470 and the change of the BOX CHK pin level;

[0074] If the BOX CHK pin level change is consistent with the LED lighting state of the optocoupler E470, that is, when the LED is lit, the BOXCHK pin level becomes low; when the LED is not lit, the BOX CHK pin level remains high, it indicates that the JP631 switch is working properly;

[0075] If the BOX CHK pin level change is inconsistent with the LED lighting state of the optocoupler E470, or the JP631 switch state is inconsistent with expectations, that is, the switch is in an open circuit state but the BOX CHK pin level becomes low, it indicates that the JP631 switch is faulty or has been mistakenly operated.

[0076] Among them, the state of the open meter box is comprehensively judged: according to the level state of the BOX CHK pin, the state of the optocoupler E470 and the closing state of the JP631 switch, the actual state of the open meter box is comprehensively judged.

[0077] If all factors indicate that the open meter box is in a normally closed state, record the state and continue monitoring.

[0078] If there are abnormal factors, such as changes in the BOX CHK pin level, abnormal optocoupler E470 status, or inconsistent JP631 switch status, record the abnormal situation and jump to step 4 for repair and processing.

[0079] refer to Figure 1 as well as Figure 5 As shown, in the step three, the following steps are included:

[0080] Step 1: The upper diode of diode D7 is turned on, and the process continues to Step 2;

[0081] Step 2. When the power grid is out but the supercapacitor SC1 still has enough power, the BOX CHK pin should maintain a stable level state and be in a high level state. At this time, observe the level state of the BOX CHK pin. If the BOX CHK pin level remains stable, it means that the supercapacitor SC1 can provide enough power to the left optocoupler circuit through the diode VD2, so that the meter opening detection circuit can work normally in the power grid outage state. Execute step 2. If the BOX CHK pin level changes, the BOX CHK pin level changes from a high level to a low level, then record the abnormal situation and execute step 3.

[0082] Step 3: According to the change of BOX CHK pin level, when the BOX CHK pin level changes, it indicates that the meter box is opened, triggering the alarm function of the energy meter and recording the situation, and jumping to step 4.

[0083] It should be noted that according to the change of BOX CHK pin level, when it is detected that the BOX CHK pin level changes from high to low, it indicates that the meter box is opened or there are other abnormal conditions. At this time, the electric energy meter triggers the alarm function to remind relevant personnel to pay attention and take corresponding treatment measures. At the same time, relevant personnel should record the abnormal situation, including the time of occurrence, changes in the BOX CHK pin level and other information for subsequent analysis and processing.

[0084] In the electrical detection of step 2, a multimeter is used to measure the voltage drop across the resistor R168 to confirm whether it is within a normal range. If the voltage drop is too large or too small, it indicates that the resistance value of R168 is abnormal.

[0085] In step 2 and step 3, it is also necessary to confirm in advance whether all connection points are firm and not loose or corroded;

[0086] In the step 2 of the power detection, it also includes measuring the voltage across the super capacitor SC1 and confirming whether it is gradually rising and approaching the voltage value of F5V. If the voltage of the super capacitor SC1 rises slowly or does not rise, it indicates that there is a problem with the charging circuit;

[0087] In the step 3 of the power-off detection, if the diode VD2 is not conducting, the situation is recorded, and the recorded data is: the super capacitor SC1 cannot be discharged or the diode VD2 is damaged;

[0088] It should be noted that by checking the conductivity of the diode VD2 in the power-off state, potential problems such as the supercapacitor SC1 being unable to discharge or the diode VD2 being damaged can be discovered in time, thereby ensuring the safe operation of the energy meter in the event of a power outage.

[0089] Embodiment 2

[0090] References Figures 1 to 5 As shown, the difference from the first embodiment is that the second embodiment replaces the super capacitor SC1 in the first embodiment with a rechargeable battery, and the other detection operation processes remain unchanged, and the open meter box during power outage can still be detected.

[0091] The working principle provided by the present invention is as follows: the meter box opening detection function in the power grid power outage state is realized by adding four devices, namely, a diode D7, a resistor R168, a super capacitor SC1 and a diode VD2; when the power grid has power, F5V supplies power to the left optocoupler circuit through the upper diode of D7, so that the meter box opening detection circuit works normally; at the same time, F5V charges the super capacitor SC1 through the lower diode of D7 and the resistor R168; when the power grid is powered off, the super capacitor SC1 supplies power to the left optocoupler circuit through the diode VD2, so that the meter box opening detection circuit works normally in the power grid power outage state, thereby realizing the function of power outage meter box opening detection.

[0092] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any figure mark in the claims should not be regarded as limiting the claims involved.

[0093] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for detecting an open meter box when an electric energy meter is out of power, characterized in that: The steps are as follows: Step 1, preparation stage: Use a voltmeter or multimeter to measure the voltage of the power grid to confirm whether the current power grid has power. If the power grid has power, proceed to step 2. If the power grid is out of power, skip step 2 and proceed to step 3. Step 2: Power detection: When the grid is powered, observe whether the upper diode of diode D7 is turned on, check whether the charging circuit composed of resistor R168 and the super capacitor SC1 is working properly, and observe the level state of the BOX CHK pin. According to the test results, determine whether the meter box is in a normal state; Step 3: No-power detection: When there is no power in the grid, observe whether the diode VD2 is turned on, observe the level state of the BOX CHK pin, and determine whether the level of the BOX CHK pin changes. According to the detection results, determine whether the meter box is in a normal state; Step 4: Repair and processing.

2. The method for detecting an open meter box in a power outage of an electric energy meter according to claim 1, characterized in that: In the step 2, the following steps are included: S1. If the upper diode of diode D7 is turned on, F5V charges supercapacitor SC1 through the lower diode of D7 and resistor R168, and then proceeds to step S2. If the upper diode of diode D7 is not turned on, F5V power supply cannot supply power to the left optocoupler circuit. This situation is recorded and the process goes to step 4. S2, judging the charging circuit composed of the resistor R168 and the established super capacitor SC1, if the charging circuit works normally, executing step S3, if the charging circuit does not work normally, checking whether the resistor R168 is damaged, recording the situation, and jumping to step 4; S3. Measure the level status of the BOX CHK pin. If the BOX CHK pin level does not jump, it means that the meter box is open normally. If the BOX CHK pin level changes, jump to step 4.

3. The method for detecting an open meter box in a power outage of an electric energy meter according to claim 1, characterized in that: In the step three, the following steps are included: Step 1, the upper diode of diode D7 is turned on, and then continue to Step 2; Step 2. Observe the level status of the BOX CHK pin. If the BOX CHK pin level remains stable, the super capacitor SC1 supplies power to the left optocoupler circuit through the diode VD2, so that the meter-opening detection circuit in the power outage state works normally. Execute step 2. If the BOX CHK pin level changes, record the situation and execute step 3. Step 3: According to the change of BOX CHK pin level, when the BOX CHK pin level changes, it indicates that the meter box is opened, triggering the alarm function of the energy meter and recording the situation, and jumping to step 4.

4. The method for detecting an open meter box in a power outage of an electric energy meter according to claim 2, characterized in that: In the electrical detection of step 2, a multimeter is used to measure the voltage drop across the resistor R168 to confirm whether it is within a normal range. If the voltage drop is too large or too small, it indicates that the resistance value of R168 is abnormal.

5. The method for detecting an open meter box in a power outage of an electric energy meter according to claim 1, characterized in that: In step 2 and step 3, it is also necessary to confirm in advance whether all connection points are firm and not loose or corroded.

6. The method for detecting an open meter box in a power outage of an electric energy meter according to claim 2, characterized in that: In the step 2 of power detection, it also includes measuring the voltage across the super capacitor SC1 and confirming whether it is gradually rising and approaching the voltage value of F5V. If the voltage of the super capacitor SC1 rises slowly or does not rise, it indicates that there is a problem with the charging circuit.

7. The method for detecting an open meter box in a power outage of an electric energy meter according to claim 3, characterized in that: In the step 3 of the power-off detection, if the diode VD2 is not conducting, this situation is recorded, and the recorded data is: the super capacitor SC1 cannot be discharged or the diode VD2 is damaged.

8. The method for detecting an open meter box in a power outage of an electric energy meter according to claim 1, characterized in that: The step 4 includes the following stages: Phase 1: Troubleshooting and recording phase: According to the abnormal conditions recorded in the power-on and power-off detection, the cause of the circuit abnormality is investigated; Phase 2: Replace or repair faulty components: Replace damaged components based on the results of the investigation, and re-weld or tighten the connection points for poor connections; Phase 3, functional test phase: After replacing or repairing the faulty component, re-perform the functional test, repeat the power-on or power-off detection process, and observe the conduction of diode D7 or VD2 and the level status of the BOX CHK pin again to ensure that the meter box can work normally with or without power, and the level status of the BOX CHK pin is correct. Stage 4: Recording and feedback stage: Record all operations, inspection results and test results during the maintenance process and provide feedback to relevant departments; Stage 5: Power supply restoration stage: After the functional test shows normal results and the records are completed, restore the power supply and observe the operation of the meter box.

9. The method for detecting an open meter box in a power outage of an electric energy meter according to claim 8, characterized in that: In the first stage, the troubleshooting includes checking whether the diodes D7 and VD2 are damaged or poorly connected, checking whether the resistor R168 is damaged or has a changed resistance, and checking whether the supercapacitor SC1 is leaking or has a reduced capacity.

10. The method for detecting an open meter box in a power outage of an electric energy meter according to claim 8, characterized in that: In the first stage, troubleshooting also includes using a multimeter to detect abnormal components.

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