Analog quantity statistical value test method for reducing synchronization requirement

Abstract

The invention discloses an analog quantity statistical value test method capable of reducing synchronization requirements, and belongs to the technical field of electric power. A standard device applies continuous periodic voltage output to equipment to be tested and reads a statistical voltage effective value of the equipment to be tested; the standard statistical voltage effective value output by the standard device is compared with the standard statistical voltage effective value to calculate the measurement error of the statistical voltage effective value, so that the technical problems that the synchronization requirement between the standard device and the equipment to be tested is effectively reduced, and the test can be carried out without synchronization are solved; according to the method, the accurate measurement result can still be obtained even if the time synchronization error exists between the standard device and the to-be-tested device and even under the condition of no time synchronization, the method is suitable for different complex environment tests, the test steps and process are simplified, the test efficiency is improved, and the more comprehensive and credible test result is ensured.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a method for testing analog quantity statistics with reduced synchronization requirements. Background Art

[0002] In the power system, in order to ensure the accuracy of important electrical parameters such as voltage, current, and frequency, value transfer is required. The so-called value transfer is to calibrate the test accuracy of relatively low-level test equipment (device under test) through a higher-level standard. For example, common multimeters or electric energy meters need to output standard voltage, current, and frequency through a higher-level standard, and then compare the voltage, current, or frequency readings of the standard with the test readings of the device under test to evaluate the accuracy level of the device under test.

[0003] This type of test generally does not require time synchronization between the standard device and the device under test. It only requires the standard device to continuously output relatively stable voltage and current, and then read the real-time voltage and current values ​​from the device under test for comparison.

[0004] However, there is another type of electrical parameters that are statistical types rather than real-time values, such as the minute effective value of a voltage monitoring device, which is defined as the root mean square value of the effective values ​​of all voltage second data within 1 minute. It is a statistical value of multiple voltage second data.

[0005] For the error measurement of minute effective value, two methods are generally used at the same time (see standard DL / T500-2017 Technical Conditions for Use of Voltage Monitors for details):

[0006] Method 1: After preheating for 30 minutes, test the voltage monitor voltage rating corresponding to the lower limit of the measurement range, the measurement voltage rating, and the upper limit of the measurement range corresponding to the detection voltage rating (at least 3 test points). After the test voltage stabilizes at each test point, read U at least twice. 1min Measure the data and take its arithmetic mean as the measurement result.

[0007] Method 1 is to output a continuous and stable standard voltage U to the voltage monitor through a standard device. N , then read the minute effective value U of the voltage monitor X , and then through U N and U X Calculate the error of the minute effective value of the voltage monitor.

[0008] Method 2: Set the nominal voltage of the voltage monitor system under test, set the upper (lower) limit of the set voltage to ±10% of the nominal voltage of the system, and query and clear the statistical data saved by the voltage monitor.

[0009] Starting from 00 seconds on the clock, within 1 minute, the rated voltage is applied to the voltage monitor for 20 seconds, and 120% of the rated voltage is applied for 40 seconds. It should be recognized as an increase in voltage exceeding the upper limit time of 1 minute.

[0010] Starting from 00 seconds on the clock, within 1 minute, apply the rated voltage to the voltage monitor for 40 seconds and apply 120% of the rated voltage for 20 seconds. This should be recognized as an increase in the voltage qualification time of 1 minute.

[0011] Starting from 00 seconds on the clock, within 1 minute, the rated voltage is applied to the voltage monitor for 20 seconds, and 80% of the rated voltage is applied for 40 seconds. This should be recognized as an increase in the voltage exceeding the lower limit time by 1 minute.

[0012] Starting from 00 seconds on the clock, within 1 minute, apply the rated voltage to the voltage monitor for 40 seconds and 80% of the rated voltage for 20 seconds. This should be recognized as an increase in the voltage qualification time of 1 minute.

[0013] From the clock 00 seconds, within 1 minute, apply the rated voltage to the voltage monitor for 40 seconds, the working power supply voltage drops to zero, and recovers to the rated voltage after 1 minute. The query and verification voltage monitor should not add statistics to the record of the voltage that is less than 1 minute just now. The qualified time, time exceeding the upper limit and time exceeding the lower limit of the voltage monitor remain unchanged.

[0014] Method 2 is to indirectly judge whether the minute effective value is qualified through a sampling time test. The specific method is: set the set voltage upper limit of the voltage monitor to +10% of the rated voltage. From the clock 00 seconds, within 1 minute, apply the rated voltage (qualified section) to the voltage monitor through the standard for 20 seconds, and apply 120% of the rated voltage (exceeding the upper limit section) for 40 seconds, and judge whether the voltage monitor counts the minute effective value of the process into the voltage exceeding the upper limit section; similarly, from the clock 00 seconds, within 1 minute, apply the rated voltage (qualified section) to the voltage monitor through the standard for 40 seconds, and apply 120% of the rated voltage (exceeding the upper limit section) for 20 seconds, and judge whether the voltage monitor counts the minute effective value of the process into the voltage qualified section, and so on.

[0015] The traditional test method for the minute effective value of voltage monitor has the following shortcomings:

[0016] Although method 1 is simple and feasible, the standard device continuously outputs a stable voltage amplitude, which cannot simulate the fluctuations in actual power grid operation. The test results cannot measure the accuracy of the minute effective value of the voltage monitor when the measured voltage continuously fluctuates.

[0017] Method 2 requires that the standard device applies a specified voltage amplitude to the voltage monitor at a certain time (such as 00 seconds and 40 seconds) and lasts for a specified time. To achieve this goal, the clocks of the standard device and the voltage monitor must be synchronized, otherwise the two different clock systems cannot achieve the test purpose.

[0018] However, it is relatively difficult for current voltage monitors to synchronize their clocks with the standard device, or the synchronization accuracy is not high, which can easily affect the credibility of the test results. When multiple voltage monitors are synchronized for batch testing, if the clock systems between each voltage monitor and the standard device are not synchronized or the synchronization accuracy is not high, the impact will be more serious.

[0019] For example, in the traditional test method: starting from the clock 00 seconds, the rated voltage (qualified section) is applied to the voltage monitor through the standard for 20 seconds, and 120% of the rated voltage (exceeding the upper limit section) is applied for 40 seconds to determine whether the voltage monitor has counted the minute effective value of the process into the voltage exceeding the upper limit section.

[0020] The standard device starts to output the rated voltage at 0s, changes to 120% of the rated voltage after 20s, and ends after 40s.

[0021] The output process of the standard instrument is as follows Figure 8 As shown in the figure, if the clock of the voltage monitor is completely synchronized with the clock of the standard, the voltage sequence measured in the 1-minute measurement window of the voltage monitor is also 100% U at 0 seconds, changes to 120% U at 20 seconds, and ends at 40 seconds, as shown in the figure. Fig. 9 As shown; however, if the clocks between the standard and the voltage monitor are not synchronized or the synchronization error is large, if the synchronization time difference is +5s, the voltage increase process felt within the 1-minute measurement window of the voltage monitor is as follows Fig.10 shown.

[0022] exist Fig. 9 In the process, since the clocks of the standard source and the voltage monitor are synchronized, the 1-minute measurement window of the voltage monitor and the 1-minute output process of the standard source are completely consistent, so what is measured is what is applied, and the expected result can be effectively measured.

[0023] exist Fig.10 In the test, due to the +5 second time difference between the standard source and the voltage monitor clock, after the standard source outputs at 0 seconds, the voltage monitor begins to enter the 1-minute measurement window at the 5th second. Therefore, the voltage output process finally measured by the voltage monitor is: 100% U for 15 seconds, 120% U for 40 seconds, and 0% U for 5 seconds. It can be seen that the output of the standard and the measured sequence of the voltage monitor will inevitably cause the final test conclusion to fail due to the time misalignment, and even lead to an erroneous conclusion. Summary of the invention

[0024] The purpose of the present invention is to provide a method for testing analog quantity statistics with reduced synchronization requirements, thereby solving the technical problem of effectively reducing the synchronization requirements between a standard device and a device to be tested, and even allowing testing without synchronization.

[0025] To achieve the above object, the present invention adopts the following technical solution:

[0026] A method for testing analog quantity statistics with reduced synchronization requirements comprises the following steps:

[0027] Step 1: Initialize the standard device, the device under test and the host computer. The standard device and the device under test communicate with the host computer through a data line, and the standard device and the device under test are electrically connected;

[0028] Set the parameters of periodic voltage output in the host computer, including output period T, statistical measurement window T w , the voltage curves and durations of the multiple stages contained in the output cycle T;

[0029] The host computer sends the parameters of the periodic voltage output to the standard device and sets the statistical measurement window T w Send to the device under test;

[0030] Step 2: The standard device applies a periodic voltage to the device under test according to the parameters of the periodic voltage output. The voltage change process of the periodic voltage is divided into multiple stages, and each stage has a different voltage curve and duration;

[0031] Step 3: The device under test is measured in each statistical measurement window T w Record the voltage changes at each stage, calculate and output the effective voltage value U in the current minute X ;

[0032] The device under test will measure the effective value of the voltage U X Send to the host computer;

[0033] Step 4: The standard device calculates the standard statistical voltage effective value U in the current cycle in real time based on the output N , and upload it to the host computer;

[0034] Step 5: The host computer converts the voltage effective value U X Compared with the standard statistical voltage effective value U N By comparison, the measurement error of the statistical voltage effective value is obtained;

[0035] Step 6: The host computer modifies the parameters of the periodic voltage output, shortens the period duration or changes the voltage curves at each stage, and performs multiple periodic tests according to the methods of steps 1 to 5 to simulate complex power grid fluctuations;

[0036] Step 7: The host computer records each test result and generates an error report for the device under test.

[0037] Preferably, the standard device is a reference voltage source, and the device under test is used to measure the voltage amplitude output by the standard device.

[0038] Preferably, when executing step 2, the standard device starts to apply periodic voltage output, and the periodic duration is the output period T. Within the output period T, the output voltage change of the standard device is divided into m stages, and the slope of the voltage curve output in each stage is different, and it is cyclic, T = t1 + t2 + ... + t m , where t1, t2, t m Represents the duration of different stages within an output cycle T.

[0039] Preferably, the statistical measurement window T w Covering a complete sampling cycle of the device under test, the statistical measurement window T w Contains at least one output period T.

[0040] Preferably, the complete sampling period is 1 second or 1 minute.

[0041] Preferably, when executing step 6, when shortening the cycle length, specifically shortening the output cycle T, at this time t1, t2, t m All are shortened proportionally.

[0042] Preferably, the value of the output period T satisfies T=t1+t2+...+t m and T = T w / n, where t1, t2, t m and n are both positive integers.

[0043] The present invention discloses a method for testing the statistical value of analog quantity with reduced synchronization requirements, which solves the technical problem of effectively reducing the synchronization requirements between the standard device and the device under test and performing the test without synchronization. The present invention is aimed at statistical effective value tests such as the statistical voltage effective value of the device under test, by setting the measurement window T w It is subdivided into n periodic small windows T for cyclic output, ensuring that even if there is a time synchronization error between the standard instrument and the device under test, each test window T wThe added sequence felt by the device under test remains consistent with the expected output of the standard, which greatly reduces the time synchronization requirements between devices. Even in the absence of time synchronization, accurate measurement results can still be obtained. Through periodic voltage output, various power grid fluctuation scenarios can be flexibly simulated, which is suitable for different complex environment tests. It not only simplifies the test steps and processes, so that only one method can cover the existing multiple test requirements, but also improves the test efficiency and ensures more comprehensive and reliable test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a flow chart of the present invention;

[0045] Figure 2 The waveform diagram of the standard device of the present invention is that the voltage of 100%U is outputted at 0s, and after t1=20s, the voltage of 120%U is outputted, and the voltage of 120%U is outputted for t2=40s in a continuous cycle;

[0046] Figure 3 It is a schematic diagram of the position of the statistical measurement window in the waveform diagram of the cyclic output when the clocks of the voltage monitor of the present invention and the standard device are completely synchronized;

[0047] Figure 4 It is a schematic diagram of the position of the statistical measurement window in the waveform diagram of the cyclic output when there is a +5 second time difference between the voltage monitor of the present invention and the standard device clock;

[0048] Figure 5 The schematic diagram of the position of the statistical measurement window in the waveform diagram of the cyclic output is a schematic diagram of the time difference between the voltage monitor and the standard device of the present invention of +55 seconds;

[0049] Figure 6 The present invention uses a 1-minute statistical measurement window T w Schematic diagram divided into n T periods;

[0050] Figure 7 is a schematic diagram of a multi-stage voltage curve within an output period T of the present invention;

[0051] Figure 8 It is a schematic diagram of the output waveform of the standard device in the background technology;

[0052] Fig. 9 The position of the statistical measurement window in the output waveform diagram of the standard device when the clocks of the voltage monitor and the standard device in the background technology are completely synchronized;

[0053] Fig.10 The present invention is to show the position of the statistical measurement window in the output waveform diagram of the standard device when the clocks of the voltage monitor and the standard device in the background technology are not synchronized. DETAILED DESCRIPTION

[0054] like Figure 1-Figure 7 A method for testing analog quantity statistics with reduced synchronization requirements is shown, comprising the following steps:

[0055] Step 1: Initialize the standard device, the device under test and the host computer. The standard device and the device under test communicate with the host computer through data lines, and the standard device and the voltage monitor are electrically connected;

[0056] The standard device is a reference voltage source, and the device under test is used to measure the voltage amplitude output by the standard device.

[0057] The device to be tested is a voltage monitor or other voltage monitoring (detection) equipment. In this embodiment, a voltage monitor is used as an application example.

[0058] Set the parameters of periodic voltage output in the host computer, including output period T, statistical measurement window T w , the voltage curves and durations of the multiple stages contained in the output cycle T;

[0059] In this embodiment, the statistical voltage effective value is explained by taking the voltage minute effective value as a specific example.

[0060] Statistical measurement window T w is the statistical value width of the voltage monitor, the typical voltage minute effective value U 1min For example, T w For 1 minute; while the voltage second data U 1s The corresponding T w is 1 second.

[0061] The host computer sends the parameters of the periodic voltage output to the standard device and sets the statistical measurement window T w Sent to voltage monitor;

[0062] Step 2: The standard device applies a periodic voltage to the voltage monitor according to the parameters of the periodic voltage output. The voltage change process of the periodic voltage is divided into multiple stages, and each stage has a different voltage curve and duration;

[0063] When executing step 2, the standard device starts to apply periodic voltage output, and the period length is the output period T. Within the output period T, the output voltage change of the standard device is divided into m stages. The slope of the voltage curve output in each stage is different and is repeated. T=t1+t2+...+t m , that is, the output period T is the sum of the duration of each stage, where t1t, 2t, t m Represents the duration of different stages within an output cycle T.

[0064] The statistical measurement window T wCovering a complete sampling cycle of the device under test, the statistical measurement window T w Contains at least one output period T.

[0065] The complete sampling period is 1 second or 1 minute.

[0066] In this embodiment, the voltage minute effective value U of the voltage monitor is read. X , and the standard voltage minute effective value U output by the standard device N By comparing and calculating, the accurate and reliable measurement error of the voltage minute effective value can be obtained.

[0067] The present invention optimizes the output sequence of the standard device into a periodic continuous output, which can solve the problem of inconsistency between the output and the actual measured duration of each added amount caused by clock asynchrony.

[0068] like Figure 2 The voltage waveforms of the two stages are shown in the figure. At this time, the slopes of the voltage curves of the two stages are both 0. The standard device starts to output a voltage of 100% U at 0s, and after t1=20s, it changes to an output voltage of 120% U, which lasts for t2=40s. Then, it starts to output a voltage of 100% U again, which lasts for t1=20s, and changes to an output voltage of 120% U, which lasts for t2=40s, and the output continues in this cycle.

[0069] In this case, if the voltage monitor and the standard clock are completely synchronized, the 1-minute measurement window of the voltage monitor is as follows: Figure 3 As shown in the traditional technology Fig. 9 The effect is exactly the same.

[0070] However, if there is a +5 second time difference between the reference source and the voltage monitor clock, the 1 minute measurement window of the voltage monitor is Figure 4 As shown, it can be seen that the situation within the 1-minute test window in this case is different from the corresponding Fig.10 different. Fig.10 The voltage amplitude in the last 5 seconds is 0%U, and Figure 4 The voltage amplitude in the last 5 seconds is 100% U, which just makes up for Fig.10 In this mode, the t1 phase lacks 5 seconds of 100% U voltage.

[0071] Taking the minute voltage effective value of the voltage monitor as an example, the formula is derived and calculated to prove that the measurement window T w When sliding arbitrarily on the source's cyclic sequence output (horizontal axis), as long as the measurement window T w does not slide out of the output sequence, then the measurement window T w The effective value of the cycle obtained within is consistent with the theoretical value of the source output.

[0072] The nth cycle of the source output is represented by Tn Indicates that the mth stage in the T period is represented by t m Indicates that the third second data of the T1 cycle t2 phase is represented by U 1.2.3 Indicates. Figure 4 The standard minute effective value of the source output, combined with the definition and calculation formula of the minute voltage effective value in the standard DL / T500, can be obtained as the minute voltage effective value U of the source output. N It can be expressed as:

[0073]

[0074] It can be seen that the voltage monitor is not synchronized with the standard source clock, causing T w The first second data obtained by the window is not U 1.1.1 , but U 1.1.6 , relative to U N Less U 1.1.1 To U 1.1.5 5 seconds of data, but T w The last 5 seconds of the window also take the U of the T2 period 2.1.1 To U 2.1.5 5 seconds of data.

[0075] According to the previous description, the source is output in a cycle with T as the period, that is, the second data of the same offset within the cycle are equal, that is:

[0076] ∪ 1.1.1 =∪ 2.1.1 =...=∪ n.1.1 ;

[0077] ∪ 1.2.1 =∪ 2.2.1 =...=∪ n.2.1 ;

[0078] Substituting the above equivalent relationship into U X In the expression, we can get:

[0079] It can be seen that although the voltage monitor is not synchronized with the standard source clock, because the standard source adopts a periodic addition method, the missing data in the previous cycle will be supplemented in the subsequent cycle, and the final theoretical value is consistent with that in the fully synchronized state.

[0080] In this embodiment, although the voltage monitor has a clock error of 5 seconds with the standard device, the voltage obtained in the 1-minute measurement window is still 100% U at 20 seconds and 120% U at 40 seconds.

[0081] If the time difference between the two systems is +55 seconds, the voltage monitor 1 minute measurement window result can be obtained as follows Figure 5As shown in the figure, the voltage process felt by the voltage monitor at this time is: 120% U for 5 seconds, 100% U for 20 seconds, and 120% U for 35 seconds. According to the definition of voltage minute effective value (RMS value of voltage effective value for 60 seconds in one minute), Figure 3 , Figure 4 , Figure 5 The minute effective values ​​of the voltage are completely equal, that is, when the output of this method is adopted, whether the clocks between the standard device and the voltage monitor are synchronized or not, the test purpose and results that are completely consistent in theory can be obtained.

[0082] for Figure 5 , the voltage monitor senses a 1-minute measurement window T w The effective voltage value within a minute (when the voltage monitor clock lags behind the standard source clock by 55 seconds) can be expressed as:

[0083]

[0084] It can be seen that the voltage monitor measures U X With standard source output U N The theoretical value is still consistent.

[0085] Similarly, for Figure 6 , Figure 7 The same conclusion can be drawn. It can be seen that the test method of this case (different from the one-time output method in the traditional and standard) can effectively remove the test error caused by time asynchrony and improve the credibility of the test results. At the same time, the switching process between multiple cycles T and the multiple stage switching process within the cycle T can simulate the voltage fluctuation of the power grid more and better than the traditional one-time increase output, and test the processing ability of the voltage monitor under complex fluctuation conditions.

[0086] Step 3: The voltage monitor measures the voltage in each statistical measurement window T w Record the voltage changes at each stage, calculate and output the effective voltage value U in the current minute X ;

[0087] The voltage monitor measures the voltage changes at each stage and the voltage effective value U X Send to the host computer;

[0088] Step 4: The standard device calculates the standard voltage minute effective value U in the current cycle according to the output cycle T N , and upload it to the host computer;

[0089] Step 5: The host computer converts the voltage effective value U X With standard voltage minute effective value U N By comparison, the measurement error of the voltage minute effective value is obtained;

[0090] Step 6: The host computer modifies the parameters of the periodic voltage output, shortens the period duration or changes the voltage curves at each stage, and performs multiple periodic tests according to the methods of steps 1 to 5 to simulate complex power grid fluctuations;

[0091] When executing step 6, when shortening the cycle time, specifically shortening the output cycle T, at this time t1, t2, t m All are shortened proportionally.

[0092] The value of the output period T satisfies T=t1+t2+...+t m and T = T w / n, where t1, t2, t m and n are both positive integers.

[0093] In this embodiment, the duration of each period in the periodic voltage output is represented by T, the first output period is T1, the second output period is T2, etc., then T = T1 = T2 = ... = T n .

[0094] Change the period T from Figure 3 The 1 minute is shortened to 6 seconds, and the voltage increase relationship within the cycle is proportionally reduced, that is, t1 = 2 seconds, t2 = 4 seconds, T = t1 + t2 = 6 seconds. Through proportional calculation, it can be known that in this mode, the voltage obtained in the 1-minute measurement window of the final voltage monitor is still 100% U of 20 seconds and 120% U of 40 seconds. The result is the same as Figure 3 It is consistent, but simulates 10 periodic voltage fluctuations, which can better test the accuracy of voltage monitors under continuous voltage fluctuations than traditional methods.

[0095] When used specifically, the method proposed in the present invention can be used as long as the addition method satisfies the relationship T=t1+t2 and T=60 / n (where t1, t2, and n are all positive integers). In this embodiment, T w =60, i.e., a statistical measurement window of 1 minute.

[0096] When the clock error between the voltage monitor and the standard is uncertain, the statistical measurement window T w Add one or more cycles T to achieve the statistical measurement window T w The complete sampling cycle of the voltage monitor is covered to achieve increased quantity.

[0097] In this embodiment, the voltage variation process within each voltage output cycle T can be further subdivided to better simulate the complex power grid fluctuation process: Figure 7As shown, the slope of the voltage curve in each stage is not 0. According to the above analysis, it is easy to know that as long as the output period T and the detection window T w Between them, T=T w / n (where n is a positive integer), then the test of statistical effective value within a period of time, such as the voltage minute effective value of a voltage monitor, can be performed by increasing the amount of test using the method disclosed in the present invention.

[0098] Similarly, the effective value per second of a voltage monitor is defined as the root mean square value of the effective value of the voltage of 10 cycles within 1 second.

[0099] A similar method as described above can be used in this embodiment, as long as the voltage output waveform of the standard device is completely repeated within each second, and there is no need to worry about whether the voltage is a constant output. Then the effective value of the second voltage measured by the voltage monitor should be theoretically completely consistent with the output value of the standard device, and the size of this value is not affected by the clock synchronization error between the two.

[0100] Step 7: The host computer records each test result and generates an error report for the voltage monitor.

[0101] The analog quantity statistical value testing method with reduced synchronization requirements of the present invention solves the technical problem of effectively reducing the synchronization requirements between the standard device and the voltage monitor and performing the test without synchronization. The present invention is aimed at the statistical effective value test of the voltage minute effective value of the voltage monitor, and the measurement window T is set to w It is subdivided into n periodic small windows T for cyclic output, ensuring that even if there is a time synchronization error between the standard instrument and the device under test, each test window T w The added sequence sensed by the internal voltage monitor is consistent with the output of the standard device, which greatly reduces the time synchronization requirements between devices. Even without time synchronization, accurate measurement results can still be obtained. Through periodic voltage output, various power grid fluctuation scenarios can be flexibly simulated, which is suitable for different complex environment tests. It not only simplifies the test steps and processes, so that only one method can cover the existing multiple test requirements, but also improves the test efficiency and ensures more comprehensive and reliable test results.

Claims

1. A method for testing analog quantity statistics with reduced synchronization requirements, characterized in that: The steps include: Step 1: Initialize the standard device, the device under test and the host computer. The standard device and the device under test communicate with the host computer through a data line, and the standard device and the device under test are electrically connected; Set the parameters of periodic voltage output in the host computer, including output period T, statistical measurement window T w , the voltage curves and durations of the multiple stages contained in the output cycle T; The host computer sends the parameters of the periodic voltage output to the standard device and sets the statistical measurement window T w Send to the device under test; Step 2: The standard device applies a periodic voltage to the device under test according to the parameters of the periodic voltage output. The voltage change process of the periodic voltage is divided into multiple stages, and each stage has a different voltage curve and duration; Step 3: The device under test is measured in each statistical measurement window T w Record the voltage changes at each stage, calculate and output the effective voltage value U in the current minute X ; The device under test will measure the effective value of the voltage U X Send to the host computer; Step 4: The standard device calculates the standard statistical voltage effective value U in the current cycle in real time based on the output N , and upload it to the host computer; Step 5: The host computer converts the voltage effective value U X Compared with the standard statistical voltage effective value U N By comparison, the measurement error of the statistical voltage effective value is obtained; Step 6: The host computer modifies the parameters of the periodic voltage output, shortens the period duration or changes the voltage curves at each stage, and performs multiple periodic tests according to the methods of steps 1 to 5 to simulate complex power grid fluctuations; Step 7: The host computer records each test result and generates an error report for the device under test.

2. The method for testing analog quantity statistics with reduced synchronization requirements as claimed in claim 1, characterized in that: The standard device is a reference voltage source, and the device under test is used to measure the voltage amplitude output by the standard device.

3. The method for testing analog quantity statistics with reduced synchronization requirements as claimed in claim 1, characterized in that: When executing step 2, the standard device starts to apply periodic voltage output, and the period length is the output period T. Within the output period T, the output voltage change of the standard device is divided into m stages. The slope of the voltage curve output in each stage is different and is repeated. T=t1+t2+...+t m , where t1, t2, t m It represents the duration of different stages in an output cycle T. m is a positive integer, indicating that there are m stages.

4. The method for testing analog quantity statistics with reduced synchronization requirements as claimed in claim 1, characterized in that: The statistical measurement window T w Covering a complete sampling cycle of the device under test, the statistical measurement window T w Contains at least one output period T.

5. The method for testing analog quantity statistics with reduced synchronization requirements as claimed in claim 4, characterized in that: The complete sampling period is 1 second or 1 minute.

6. The method for testing analog quantity statistics with reduced synchronization requirements as claimed in claim 4, characterized in that: When executing step 6, when shortening the cycle time, specifically shortening the output cycle T, at this time t1, t2, t m All are shortened proportionally.

7. The method for testing analog quantity statistics with reduced synchronization requirements as claimed in claim 4, characterized in that: The value of the output period T satisfies T=t1+t2+...+t m and T = T w / n, where t1, t2, t m and n are both positive integers.

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