A method for intermediate testing in high-temperature accelerated life testing of smart energy meters

Abstract

This invention discloses a method for intermediate testing in a high-temperature accelerated life test of smart meters. All smart meter samples are divided into M groups, with N meters in each group. Each group is equipped with a circuit switch. The N groups of smart meter samples are connected in series with the input power supply via the circuit switch, and then connected to a load, forming a series circuit structure. The input power supply, load, and all sockets and plugs are placed outside the high-temperature test chamber. This invention performs intermediate testing every 72 hours, allowing the failure time of the samples in the high-temperature accelerated life test to be controlled within 72 hours. The longest time the tested sample is removed from the high temperature during intermediate testing is controlled to approximately 10 minutes, and the temperature decay is controlled within 3°C, keeping the impact of temperature decay on measurement accuracy within an acceptable range. The method of removing the samples from the high-temperature test chamber only requires personnel to wear ordinary cotton gloves to prevent injury from the high temperature of the samples.

Description

Technical Field

[0001] This invention relates to the field of smart energy meter testing technology, and in particular to a method for intermediate testing of smart energy meters in high-temperature accelerated life testing. Background Technology

[0002] Life tests of smart energy meters typically use high temperatures as accelerated stress. In order to obtain the failure time of the sample during the test in a timely manner, it is necessary to continuously detect the main functional indicators of the smart energy meter, such as the measurement error, during the test.

[0003] First, life testing is typically a statistical reliability test with a large sample size, requiring considerable time for intermediate testing, which may affect the rigor of the high-temperature accelerated testing itself. Second, since accelerated stress testing uses high temperatures, the functional performance testing of the smart meter samples must be conducted under high-temperature conditions, creating operational difficulties for intermediate testing. Furthermore, testing the functional performance of each smart meter sample requires power disconnection and rewiring, which can affect the electrical stress conditions of other smart meter samples. Therefore, the challenge of this test is to safely conduct functional testing of each smart meter sample within the shortest possible time without affecting the operation of other smart meters.

[0004] The intermediate testing problem in traditional high-temperature accelerated life testing of smart meters has evolved from the initial lack of intermediate testing to the later practice of removing the meters from the high-temperature test chamber for intermediate testing during interrupted testing. However, this approach has consistently failed to fully meet the technical requirements for intermediate testing in the high-temperature accelerated life testing of smart meters.

[0005] Existing technical solution one: No intermediate testing is performed; only pre- and post-test testing is conducted. That is, no intermediate testing is performed during the high-temperature accelerated life test of smart meters; instead, pre- and post-test testing is used to determine the number of samples that have failed. This method simplifies the test and greatly improves operability. The disadvantages of this solution are as follows: it cannot periodically determine whether the smart meter samples have failed, thus it cannot know the failure time of each failed sample, and therefore cannot establish a failure-time model, i.e., a life model. This prevents the test from achieving its core objective of revealing life cycle patterns.

[0006] Existing technical solution two: Remove smart meter samples from the high-temperature test chamber for intermediate testing. This involves periodically conducting intermediate tests during the test to obtain the approximate failure time range of the samples, providing data support for statistical calculations. The disadvantages of this solution are as follows: Life test, a statistical test, typically involves a large number of samples. Removing all samples from the high-temperature test chamber at once and testing each sample individually requires power disconnection and rewiring between every two samples. This results in the samples being removed from high-temperature conditions for an extended period, causing the internal temperature of later-tested samples to be significantly lower than the set high-temperature value. Summary of the Invention

[0007] To address the relevant technical issues, the purpose of this application is to provide a method for intermediate testing in high-temperature accelerated life testing of smart energy meters.

[0008] To achieve the objectives of this application, the technical solution provided is as follows:

[0009] A method for intermediate testing of high temperature accelerated life test of smart energy meters: all smart energy meter samples are divided into M groups, each group has N smart energy meters, and each group is used with a circuit switch. The N groups of smart energy meter samples are connected in series to the input power supply through the circuit switch, and then connected to the load to form a series circuit structure. The input power supply, the load and all sockets and plugs are placed outside the high temperature test chamber.

[0010] The method includes the following steps:

[0011] Step 1) When the power supply and load are cut off for a short time, for the first group of N smart energy meter samples (A1-AN), the first group of N smart energy meters are removed from the series circuit structure by adjusting the circuit switch. The remaining M-1 groups still form a series circuit structure by the circuit switch.

[0012] Step 2) Take away the wires and circuit switches connecting the neutral and live wires at both ends of the first group of N smart energy meter samples in series, so that they can be taken out of the high temperature test chamber together with the first group of N smart energy meter samples through the connection hole of the high temperature test chamber.

[0013] Step 3) Without stopping the high-temperature conditions, directly open the door of the high-temperature test chamber;

[0014] Step 4) Pull the external wires and circuit switches of the first group of N smart energy meter samples into the high temperature test chamber, and take them out of the high temperature test chamber together with the tray of the first group of N smart energy meter samples.

[0015] Step 5) Divide the N smart energy meter samples taken out into S groups, with N / S smart energy meter samples in each group, and connect the power supply and load to the groups.

[0016] Step 6) Arrange for the S group of samples to be tested by the S group of technicians. The technicians can wear ordinary cotton gloves to carry out the testing work and ensure that the testing time for each sample is controlled within the preset time.

[0017] Step 7) After each group of S completes the test and records the power metering error, disconnect the power supply and load of each group and reconnect the N samples in series.

[0018] Step 8) Open the door of the high-temperature test chamber;

[0019] Step 9) Put N samples back into the high-temperature test chamber and lead the front and rear connecting wires out of the high-temperature test chamber through the lead hole;

[0020] Step 10) Reset the N samples to be tested and connect them in series into the circuit structure;

[0021] Step 11) Repeat the above process to test the M-1 group of samples respectively, and complete one intermediate test.

[0022] The circuit switch is a plug and socket combination structure.

[0023] In this circuit, the input power supply is connected to socket A. The first group of N smart energy meter samples is connected to plug A at one end and socket B at the other end. The adjacent second group of N smart energy meter samples is connected to plug B at one end. The other groups are connected in a similar way. In step 1), plug A is removed from socket A, plug B is removed from socket B, the first group of samples is removed from the circuit, and plug B is inserted into socket A.

[0024] Wherein, M is 4, N is 20, and S is 4.

[0025] In step 6), the preset time is 2 minutes.

[0026] The detection cycle using the method is 72 hours.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1) This invention performs an intermediate test once every 72 hours, which can control the failure time of samples in the high-temperature accelerated life test of smart energy meters within 72 hours;

[0029] 2) The method of the present invention allows the number of power outages for other samples to be controlled to 4 during intermediate detection operations, with each power outage lasting no more than 3 seconds;

[0030] 3) The longest time the sample can be removed from the high temperature during intermediate testing can be controlled to about 10 minutes, and the temperature decay is controlled to within 3℃, so that the impact of temperature decay on measurement accuracy is controlled within an acceptable range.

[0031] 4) The testing method still involves removing the sample from the high-temperature test chamber. Personnel only need to wear ordinary cotton gloves to prevent the high temperature of the sample from harming their bodies.

[0032] 5) The testing time for each sample should be controlled within 2 minutes;

[0033] 6) The convenient and quick circuit connection method allows the operation of removing each group of samples from the high-temperature test chamber to be controlled within 1 minute, and the temperature drop of the sample surface is controlled within 5℃. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the detection circuit structure in an embodiment of this application. Detailed Implementation

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when used in this specification, the words “comprising” and / or “including” indicate the presence of features, steps, operations, parts or modules, components and / or combinations thereof.

[0038] The basic conditions for the high-temperature accelerated life test of smart energy meters in this embodiment of the invention are as follows:

[0039] Test temperature conditions: 85℃; test time: 2000h; test sample quantity: 80 pieces

[0040] Test sample: Smart energy meter

[0041] The electrical stress conditions for the test were as follows: all smart energy meter samples were connected in series to a 220V AC power supply, followed by a 1500W load. See the attached diagram for details. Figure 1 The input power supply, load, and all sockets and plugs are placed outside the high-temperature test chamber.

[0042] Technical requirements for intermediate detection in the embodiments of this invention:

[0043] 1) During the test, promptly identify failed samples and record the failure time;

[0044] 2) Intermediate testing of all samples will be conducted every 72 hours;

[0045] 3) Intermediate testing mainly detects the electrical energy measurement error of each sample;

[0046] 4) For each failed sample found during intermediate testing, the failure time is recorded using the median rank method;

[0047] 5) The failure criterion for electricity metering error is ±2%.

[0048] Key technical contents of the embodiments of the present invention:

[0049] 1) Intermediate testing of smart energy meter samples still involves taking them out of the high-temperature test chamber for testing, with 20 samples taken out each time.

[0050] 2) In the electrical stress application circuit of the test samples, every 20 smart energy meter samples are grouped together, and a socket and plug are set up as a circuit switch (e.g., Figure 1 The sockets A and plug A, socket B and plug B, socket C and plug C, socket D and plug D, and socket E and plug E are used in combination. The rapid operation outside the test chamber avoids the risks of injury to technicians caused by the excessive time interval and high temperature caused by the operation inside the chamber. This achieves the requirement of quick and safe testing of each set of samples without affecting the application of electrical stress to all other samples.

[0051] 3) Furthermore, each intermediate test only requires 4 opening actions, reducing the number of times the chamber is opened. The time for each opening is controlled within 1 minute. The temperature sensor inside the high-temperature test chamber proves that the temperature drop inside the chamber caused by each opening does not exceed 5℃, and the test temperature is maintained within an acceptable range.

[0052] 3) The 20 smart meter samples taken each time were divided into 4 groups, and 4 groups of technicians were assigned to conduct the tests. Each group tested 5 smart meter samples, and the average testing time for each sample was 2 minutes, meaning that the testing time for each group could be controlled within approximately 10 minutes. Using a temperature sensor placed inside the sample housing, the internal temperature of the sample could be maintained above 82°C within 12 minutes, and the temperature decay of the sample was controlled within an acceptable range.

[0053] The operation steps of this invention are as follows:

[0054] 1) In the case of short-term power and load disconnection, for the first group of 20 smart energy meter samples (A1-A20), unplug A from socket A, unplug B from socket B, remove the first group of samples from the circuit, and insert plug B into socket A.

[0055] 2) Tuck away the wires, plugs, and sockets that connect the live and neutral wires at both ends of these 20 samples in series, so that they can be taken out of the high-temperature test chamber together with the first set of samples through the connection hole of the chamber.

[0056] 3) Open the door of the high-temperature test chamber directly without stopping the high-temperature conditions;

[0057] 4) Pull the external lead wires and plugs / sockets of the first group of 20 samples into the box, and take them out of the test box together with the tray of the first group of samples. Each group is installed on a tray and can be taken out individually.

[0058] 5) Divide the 20 removed samples into 4 groups of 5 samples each, and connect the power supply and load to each group.

[0059] 6) Four groups of technicians will be assigned to test the four groups of samples. The technicians can perform the testing by wearing ordinary cotton gloves and ensuring that the testing time for each sample is controlled within 2 minutes.

[0060] 7) After the four groups have completed the tests and recorded the power metering errors, the power supply and load of each group are removed, and the 20 samples are reconnected in series.

[0061] 8) Open the door of the high-temperature test chamber;

[0062] 9) Put the 20 samples back into the box and lead the front and rear connecting wires out of the box through the lead hole;

[0063] 10) Reconnect this group of 20 samples to the attachment. Figure 1 In the circuit;

[0064] 11) Repeat the above process to test the following three groups of 60 samples respectively, and complete one intermediate test of the plug and socket.

[0065] The beneficial effects of the technical solution of this invention are as follows:

[0066] 1) The intermediate test specified in this invention, which is performed once every 72 hours, can control the failure time of the samples in the high-temperature accelerated life test of smart energy meters within 72 hours.

[0067] 2) The method of the present invention allows the number of power outages for other samples to be controlled to 4 during intermediate detection operations, with each power outage lasting no more than 3 seconds;

[0068] 3) The longest time the sample can be removed from the high temperature during intermediate testing can be controlled to about 10 minutes, and the temperature decay is controlled to within 3℃, so that the impact of temperature decay on measurement accuracy is controlled within an acceptable range.

[0069] 4) The testing method still involves removing the sample from the high-temperature test chamber. Personnel only need to wear ordinary cotton gloves to prevent the high temperature of the sample from harming their bodies.

[0070] 5) The testing time for each sample should be controlled within 2 minutes;

[0071] 6) The convenient and quick circuit connection method allows the operation of removing each group of samples from the high-temperature test chamber to be controlled within 1 minute, and the temperature drop of the sample surface is controlled within 5℃.

[0072] In other embodiments...

[0073] 1) The set of manually plugged sockets at every 20 smart energy meter samples in the series circuit described in this invention can also be replaced by a double-pole double-throw switch to achieve the same function.

[0074] 2) In this invention, the grouping method of the samples may also be adjusted to obtain appropriate opening time, detection time, temperature removal time, etc.;

[0075] 3) In this invention, the frequency of intermediate detection can also be adjusted from 72h to other times. This is determined by comprehensively considering cost, benefits and experimental requirements.

[0076] 4) The practice of dividing each group of samples into several groups after they are taken out of the high-temperature test chamber is also determined by comprehensive consideration of factors such as detection speed, temperature decay and number of detection instruments. If there are more detection instruments, the number of groups can be increased, thereby shortening the temperature separation time and further reducing the degree of temperature decay.

[0077] It should be noted that any technical solutions not detailed in this application employ publicly known technologies.

[0078] The above description is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for intermediate detection of intelligent electric energy meter high-temperature accelerated life test, characterized in that, All smart electric energy meter samples are divided into M groups, each group has N samples and each group is respectively matched with a circuit switch, N groups of smart electric energy meter samples are connected in series through the circuit switch to the input power supply and are connected to the load, thereby forming a series circuit structure, wherein the input power supply, the load and all sockets and plugs are placed outside the high temperature test box; The method comprises the following operation steps: Step 1) in the case of cutting off the power supply and the load for a short time, for the first group of N smart electric energy meter samples (A1-AN), the first group of N smart electric energy meter samples is excluded from the series circuit structure by adjusting the circuit switch, and the remaining M-1 groups still form a series circuit structure through the circuit switch; Step 2) the wires connecting the zero and live lines of the first group of N smart electric energy meter samples and the circuit switch are collected, which facilitates the taking out of the first group of N smart electric energy meter samples through the connection hole of the high temperature test box; Step 3) without stopping the high temperature condition, the door of the high temperature test box is directly opened; Step 4) the wires introduced from outside of the first group of N smart electric energy meter samples and the circuit switch are pulled into the high temperature test box, and the first group of N smart electric energy meter samples and the tray are taken out from the high temperature test box; Step 5) the N smart electric energy meter samples taken out are divided into S groups, each group has N / S smart electric energy meter samples, and the power supply and the load are connected; Step 6) S groups of samples are arranged for S group of technicians to detect, the detection technicians can detect with ordinary cotton gloves, and the detection time of each sample is controlled within the preset time; Step 7) after S groups of samples complete the detection and record the electric energy metering error, the power supply and the load of each group are removed, and the N samples are connected in series; Step 8) the door of the high temperature test box is opened; Step 9) the N samples are put back into the high temperature test box, and the front and rear connecting wires are led out of the high temperature test box through the lead hole; Step 10) the N samples to be detected are reset and connected in series into the circuit structure; Step 11) the above process is repeated to detect the remaining M-1 groups of samples, thereby completing the intermediate detection; The circuit switch is a plug and socket matching structure; The input power supply is connected with the socket A, the first group of N smart electric energy meter samples is connected with the plug A at one end and the socket B at the other end, the second group of N smart electric energy meter samples is connected with the plug B at one end, in step 1), the plug A is pulled out of the socket A, the plug B is pulled out of the socket B, the first group of samples is excluded from the circuit, and the plug B is inserted into the socket A; The M is 4, the N is 20, and the S is 4; The preset time in step 6) is 2 minutes; The detection period of the method is 72 hours.

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