Method, system and storage medium for no-load test of ac energy meter under power frequency magnetic field

Abstract

The application discloses an AC power meter power frequency magnetic field no-load test method, system and storage medium, which saves the time for the AC power meter to perform the power frequency magnetic field no-load test. The method comprises the following steps: when the AC power meter is placed under a preset power frequency magnetic field condition, a test voltage is applied to the AC power meter, so that the AC power meter normally works; the value in a fast pulse counter is read, and the time required for the value in the fast pulse counter to increase by 1 is determined; the value in a pulse frequency register is read; the fast pulse counter and the pulse frequency register both belong to the components of a metering chip of the AC power meter; according to the time and the value in the pulse frequency register, the time tQ required for the AC power meter to generate one pulse is calculated; and if tQ is greater than a preset time, it is determined that the AC power meter power frequency magnetic field no-load test is qualified.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of alternating current energy meter calibration, and more particularly to an alternating current energy meter power frequency magnetic field no-load test method, system and storage medium. BACKGROUND

[0002] The measurement accuracy of an alternating current energy meter is closely related to its working environment, and one of the main influencing factors is the external power frequency magnetic field. When an alternating current energy meter is disturbed by an external power frequency magnetic field, it will generate a corresponding induced current. If the induced current is large, the alternating current energy meter will also generate a charge in the absence of user electricity. Therefore, when performing type evaluation of an alternating current energy meter, an important task is to perform an external power frequency magnetic field (no-load condition) test on the alternating current energy meter, which is referred to as a power frequency magnetic field no-load test. However, this test is too time-consuming and is not suitable for testing batch-produced meters.

[0003] For example, Section 9.4.1 of JJF 1245.4-2019 "Outline for Type Evaluation of Installation Type Alternating Current Energy Meter - Special Requirements and Safety Requirements" proposes the following requirements for the test: "Place the meter in the center of the external power frequency magnetic field induction coil, apply 1.1 times the nominal voltage to the voltage circuit, apply the nominal voltage to the auxiliary power supply circuit (if any), and apply no current to the current circuit, and the current terminal should be open. Apply an external power frequency magnetic field with the same frequency as the meter, change the direction and phase of the magnetic field on the meter, and take the maximum deviation of the error as the most unfavorable direction and phase condition, and continue for 20 times the theoretical starting time under this condition." During the test (i.e., within the 20 times the theoretical starting time), the meter, i.e., the alternating current energy meter, should not generate more than one pulse.

[0004] The calculation formula of the theoretical starting time τ of the alternating current energy meter is:

[0005]

[0006] In the formula, k is the meter constant, with units of imp / kWh or rev / kWh; m is the number of measurement units; U nom is the nominal voltage, with units of V; I st is the starting current, with units of A; and τ has units of s.

[0007] Taking an alternating current energy meter with specifications of "U nom is 220V, I st is 0.020A, k is 2000, and m is 1000" as an example, the theoretical starting time τ is approximately 409.09s. Therefore, the time required for testing one direction and phase is 20τ, which is approximately 2.5h, and is too time-consuming. SUMMARY

[0008] Therefore, the application provides an AC electric energy meter power frequency magnetic field no-load test method, system and storage medium to save the time of the AC electric energy meter power frequency magnetic field no-load test.

[0009] An AC electric energy meter power frequency magnetic field no-load test method comprises the following steps.

[0010] When the AC electric energy meter is placed in a preset power frequency magnetic field condition, a test voltage is applied to the AC electric energy meter to make the AC electric energy meter work normally.

[0011] The value in the fast pulse counter is read, and the time required for the value in the fast pulse counter to increase by 1 is determined.

[0012] The value in the pulse frequency register is read; the fast pulse counter and the pulse frequency register are both components of a metering chip of the AC electric energy meter.

[0013] According to the time and the value in the pulse frequency register, the time tQ required for the AC electric energy meter to generate one pulse is calculated.

[0014] If tQ is greater than a preset time, it is determined that the AC electric energy meter power frequency magnetic field no-load test is qualified.

[0015] Optionally, when the test is performed according to the metering technical specification, the power frequency magnetic field condition is preset as a power frequency magnetic field condition with a magnetic field strength of 0.5 mT, the test voltage is 1.1 times the nominal voltage, and the preset time is 20 times the theoretical starting time.

[0016] Optionally, when the test is performed according to the enterprise standard of State Grid Corporation of China, the power frequency magnetic field condition is preset as a power frequency magnetic field condition with a magnetic field strength of 0.5 mT, the test voltage is 1.15 times the nominal voltage, and the preset time is 20 times the theoretical starting time.

[0017] Optionally, the calculation of the time tQ required for the AC electric energy meter to generate one pulse according to the time and the value in the pulse frequency register comprises the following steps.

[0018] According to the formula tQ = [(n-n%10)×1.6+n%10]*t1*2, the time tQ required for the AC electric energy meter to generate one pulse is calculated.

[0019] Wherein, t1 is the time required for the value in the fast pulse counter to increase by 1; n is the value in the pulse frequency register, which is a hexadecimal number.

[0020] Optionally, the AC electric energy meter is a single-phase cost control intelligent electric energy meter or a three-phase cost control intelligent electric energy meter.

[0021] An AC electric energy meter power frequency magnetic field no-load test system comprises the following steps.

[0022] a voltage circuit, configured to apply a test voltage to the AC energy meter to make the AC energy meter work normally when the AC energy meter is placed in a preset power frequency magnetic field condition;

[0023] a control unit, configured to read a value in a fast pulse counter and determine a time required for the value in the fast pulse counter to increase by 1, read a value in a pulse frequency register, the fast pulse counter and the pulse frequency register being components of a metering chip of the AC energy meter, calculate a time tQ required for the AC energy meter to generate one pulse according to the time and the value in the pulse frequency register, and determine that the AC energy meter passes the power frequency magnetic field no-load test if the tQ is greater than a preset time.

[0024] Optionally, in the power frequency magnetic field no-load test system for the AC energy meter, when the test is performed according to the metrology technical specification, the power frequency magnetic field condition is a power frequency magnetic field condition with a magnetic field strength of 0.5 mT, the test voltage is 1.1 times the nominal voltage, and the preset time is 20 times a theoretical starting time.

[0025] Optionally, in the power frequency magnetic field no-load test system for the AC energy meter, when the test is performed according to the enterprise standard of State Grid Corporation of China, the power frequency magnetic field condition is a power frequency magnetic field condition with a magnetic field strength of 0.5 mT, the test voltage is 1.15 times the nominal voltage, and the preset time is 20 times a theoretical starting time.

[0026] Optionally, in any of the power frequency magnetic field no-load test systems for the AC energy meter, the control unit is specifically configured to calculate the time tQ required for the AC energy meter to generate one pulse according to a formula tQ=[(n-n%10)×1.6+n%10]*t1*2.

[0027] wherein t1 is the time required for the value in the fast pulse counter to increase by 1, and n is the value in the pulse frequency register, which is a hexadecimal number.

[0028] A storage medium, the storage medium storing a program, when an AC energy meter is placed in a preset power frequency magnetic field condition and a test voltage is applied to the AC energy meter to make the AC energy meter work normally, the program is executed by a processor to implement a method comprising:

[0029] read the value in the fast pulse counter and determine the time required for the value in the fast pulse counter to increase by 1; read the value in the pulse frequency register; the fast pulse counter and the pulse frequency register are both components of a metering chip of an AC power meter; calculate the time tQ required for the AC power meter to generate a pulse according to the time and the value in the pulse frequency register; if tQ is greater than a preset time, determine that the no-load test of the AC power meter under the power frequency magnetic field is qualified.

[0030] As can be seen from the technical solution above, since the fast pulse counter value is accumulated from 0 to 2 times the pulse frequency register value, the AC power meter generates a pulse, so the present application calculates the time tQ required for the AC power meter to generate a pulse according to the time required for the fast pulse counter value to increase by 1 and the value in the pulse frequency register, if tQ is greater than a preset time, for example, 20 times the theoretical starting time, it indicates that the AC power meter does not generate more than one pulse within the preset time, the no-load test of the AC power meter under the power frequency magnetic field is qualified, otherwise, it indicates that the no-load test under the power frequency magnetic field is unqualified. The present application only takes t1 to test one direction and phase, and t1 is less than the preset time, compared with the prior art which takes the preset time to test one direction and phase, the present application greatly saves the time for the AC power meter to perform the no-load test under the power frequency magnetic field, and is very suitable for testing batch-produced meters. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort based on these drawings.

[0032] Figure 1 A flow chart of the no-load test method of the AC power meter under the power frequency magnetic field disclosed by the embodiment of the present application;

[0033] Figure 2 A structure schematic diagram of the AC power meter disclosed by the prior art;

[0034] Figure 3 A flow chart of the no-load test method of the AC power meter under the power frequency magnetic field disclosed by the embodiment of the present application;

[0035] Figure 4 A flow chart of the no-load test method of the AC power meter under the power frequency magnetic field disclosed by the embodiment of the present application;

[0036] Figure 5 A structure schematic diagram of the no-load test system of the AC power meter under the power frequency magnetic field disclosed by the embodiment of the present application;

[0037] Figure 6 A storage medium structure schematic diagram is disclosed in the embodiments of the present application. DETAILED DESCRIPTION

[0038] For the sake of citation and clarity, the technical terms, abbreviations or acronyms used in the following are summarized as follows:

[0039] JJF: metrological technical specification; JJF refers to other comprehensive and basic metrological technical requirements and technical management regulations that cannot be included in the national metrological verification system and the national metrological verification regulations;

[0040] Q / GDW: national grid enterprise standard;

[0041] PowerP: Active Power Register, active power register;

[0042] PStart: Start Power Threshold Setup Register, active start power threshold setup register;

[0043] PFCnt: Active Energy Counter Register, fast pulse counter;

[0044] HFConst: High Frequency Impulse Const Register, pulse frequency register.

[0045] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0046] Referring to Figure 1 The embodiments of the present application disclose an AC electric energy meter power frequency magnetic field no-load test method to save the time for the AC electric energy meter to perform the power frequency magnetic field no-load test. The method comprises the following steps:

[0047] Step S01: When the AC electric energy meter is placed in a preset power frequency magnetic field condition, a test voltage is applied to the AC electric energy meter to make the AC electric energy meter work normally.

[0048] Specifically, when performing the power frequency magnetic field no-load test on the AC electric energy meter, the power frequency magnetic field conditions, test voltage and test time specified in different technical standards may be different. During the test, the corresponding settings can be made according to the technical standard to be followed by the AC electric energy meter. For example, JJF 1245.4-2019 “Outline for Type Evaluation of Installed AC Electric Energy Meters—Special Requirements and Safety Requirements” specifies that the power frequency magnetic field condition in which the AC electric energy meter is placed is a power frequency magnetic field condition with a magnetic field strength of 0.5 mT, the test voltage applied to the AC electric energy meter is 1.1 times the nominal voltage, and the AC electric energy meter should not generate more than one pulse within 20 times the theoretical starting time. Q / GDW 1364-2013 “Technical Specification for Single-Phase Intelligent Meters” specifies that the power frequency magnetic field condition in which the AC electric energy meter is placed is a power frequency magnetic field condition with a magnetic field strength of 0.5 mT, the test voltage applied to the AC electric energy meter is 1.15 times the nominal voltage, and the AC electric energy meter should not generate more than one pulse within 20 times the theoretical starting time. The “BACKGROUND” section of the present application file only takes JJF 1245.4-2019 as an example for illustration.

[0049] Step S02: read the value in PFCnt and determine the time t1 required for the value in PFCnt to increase by 1.

[0050] Step S03: read the value n in HFConst.

[0051] Step S04: calculate the time tQ required for the AC electric energy meter to generate one pulse according to the time t1 and the value n.

[0052] Specifically, PowerP, PStart, PFCnt and HFConst are all existing arithmetic and logic components in the metering chip of the AC electric energy meter, as shown in the following table. Figure 2 The existing working principle is as follows: when the value in PowerP is greater than the value in PStart, PFCnt starts to accumulate counting; the value in HFConst is a meter constant; when the value in PFCnt reaches 2 times the meter constant, the AC electric energy meter generates one pulse, and then the value in PFCnt is cleared and starts to accumulate counting again.

[0053] The meter constant in HFConst is generally represented by a hexadecimal number. Assuming that the meter constant is a hexadecimal number n, the conversion of the hexadecimal number n to a decimal number is (n-n%10)×1.6+n%10. Assuming that the time required for the value in PFCnt to increase by 1 is t1 and the time required for the AC electric energy meter to generate one pulse is tQ, since the AC electric energy meter will generate one pulse when the value in PFCnt accumulates from 0 to 2 times the meter constant, tQ can be calculated as [(n-n%10)×1.6+n%10]*t1*2.

[0054] In the case of a substantially constant power frequency magnetic field strength, the time required for each increase of 1 in the value of PFCnt is substantially consistent, so the time t1 determined in the step S02 can be a one-time count or an average count. When t1 is a one-time count, the corresponding determination method is, for example, recording the time point a corresponding to the change of the value of PFCnt from x to x+1, and the time point b corresponding to the change of the value of PFCnt from x+1 to x+2, and then t1 = b-a. When t1 is an average count, the corresponding determination method is, for example, recording the time point a corresponding to the change of the value of PFCnt from x to x+1, and the time point c corresponding to the change of the value of PFCnt from x+y-1 to x+y, and then t1 = (c-a) / (y-1), x≥0, y≥2.

[0055] Step S05: comparing tQ with a preset time; if tQ > the preset time, entering step S06; otherwise, entering step S07.

[0056] As known from the above, the size of the preset time depends on the technical standard to be followed by the AC energy meter during the test, for example, JJF 1245.4-2019 “Outline for Type Evaluation of Installation Type AC Energy Meter—Special Requirements and Safety Requirements” and Q / GDW 1364-2013 “Technical Specification for Single-phase Intelligent Meter” both stipulate that the preset time is 20 times the theoretical starting time.

[0057] Step S06: determining that the power frequency magnetic field no-load test of the AC energy meter is qualified, and the test ends.

[0058] Step S07: determining that the power frequency magnetic field no-load test of the AC energy meter is unqualified, and the test ends.

[0059] Specifically, the power frequency magnetic field no-load test requires that the AC energy meter should not generate more than one pulse within the preset time, that is, tQ > the preset time is required, so if tQ > the preset time is determined, it means that the power frequency magnetic field no-load test of the AC energy meter is qualified; otherwise, if tQ ≤ the preset time is determined, it means that the power frequency magnetic field no-load test of the AC energy meter is unqualified. The test of one direction and phase of the embodiment of the present application only takes time t1, and t1 < the preset time, which greatly saves the time of the power frequency magnetic field no-load test of the AC energy meter compared with the prior art which takes the preset time to test one direction and phase.

[0060] As can be seen from the above description of the embodiments of the present application, since the value in PFCnt is accumulated from 0 to 2 times the pulse frequency register value, the AC energy meter generates a pulse, so the embodiments of the present application calculate the time tQ required for the AC energy meter to generate a pulse according to the time required for the value in PFCnt to increase by 1 and the pulse frequency register value. If tQ is greater than a preset time, for example, a theoretical starting time of 20, it indicates that the AC energy meter does not generate more than one pulse within the preset time, and the no-load test of the power frequency magnetic field of the AC energy meter is qualified. Otherwise, it indicates that the no-load test of the power frequency magnetic field is unqualified. The embodiments of the present application only take t1 to test one direction and phase, and t1 < the preset time. Compared with the prior art which takes the preset time to test one direction and phase, the embodiments of the present application greatly save the time of the no-load test of the power frequency magnetic field of the AC energy meter, and are very suitable for testing batch-produced meters.

[0061] In addition, it should be noted that the execution order of the actions shown in steps S02 and S03 is not limited. The action shown in step S02 can be performed first and then the action shown in step S03 (as shown in Figure 1 ), the action shown in step S03 can be performed first and then the action shown in step S02 (as shown in Figure 3 ), or the actions shown in steps S02 and S03 can be performed simultaneously (as shown in Figure 4 ), and Figure 1 only the case of performing the action shown in step S02 first and then the action shown in step S03 is taken as an example.

[0062] Corresponding to the above method embodiments, the embodiments of the present application also disclose an AC energy meter power frequency magnetic field no-load test system, as shown in Figure 5 , comprising:

[0063] a voltage circuit 100, configured to apply a test voltage to the AC energy meter to make the AC energy meter work normally when the AC energy meter is placed in a preset power frequency magnetic field condition;

[0064] a control unit 200, configured to read the value in the fast pulse counter and determine the time required for the value in the fast pulse counter to increase by 1; read the value in the pulse frequency register; the fast pulse counter and the pulse frequency register both belong to the components of the metering chip of the AC energy meter; calculate the time tQ required for the AC energy meter to generate a pulse according to the time and the value in the pulse frequency register; and if tQ is greater than a preset time, determine that the no-load test of the power frequency magnetic field of the AC energy meter is qualified.

[0065] Optionally, in the above-disclosed AC energy meter power frequency magnetic field no-load test system, when conducting the test in accordance with the metrological technical specifications, the power frequency magnetic field condition is a power frequency magnetic field condition with a magnetic field strength of 0.5mT, the test voltage is 1.1 times the nominal voltage, and the preset time is 20 times the theoretical start-up time.

[0066] Alternatively, in the aforementioned publicly disclosed AC energy meter power frequency magnetic field no-load test system, when conducting the test in accordance with the State Grid Corporation of China's enterprise standards, the power frequency magnetic field condition is a power frequency magnetic field condition with a magnetic field strength of 0.5mT, the test voltage is 1.15 times the nominal voltage, and the preset time is 20 times the theoretical start-up time.

[0067] Optionally, in any of the above-disclosed AC energy meter power frequency magnetic field no-load test systems, the control unit 200 is specifically used to calculate the time tQ required for the AC energy meter to generate one pulse according to the formula tQ=[(nn%10)×1.6+n%10]*t1*2;

[0068] Where t1 is the time required for the value in the fast pulse counter to increment by 1; n is the value in the pulse frequency register, which is a hexadecimal number.

[0069] Furthermore, embodiments of the present invention also disclose a storage medium, such as... Figure 6 As shown, the storage medium stores a program that, when the AC energy meter is placed under a preset power frequency magnetic field condition and the AC energy meter is made to work normally by applying a test voltage to the AC energy meter, the method implemented by the program when executed by the processor includes:

[0070] Read the value in the fast pulse counter and determine the time required for the value in the fast pulse counter to increase by 1; read the value in the pulse frequency register; the fast pulse counter and the pulse frequency register are both components of the metering chip of the AC energy meter; calculate the time tQ required for the AC energy meter to generate one pulse based on the time and the value in the pulse frequency register; if tQ is greater than the preset time, the AC energy meter is deemed to have passed the no-load test of the power frequency magnetic field.

[0071] Optionally, in the above-disclosed storage medium embodiment, the power frequency magnetic field condition is a power frequency magnetic field condition with a magnetic field strength of 0.5 mT, and the test voltage is 1.1 times the nominal voltage.

[0072] Alternatively, in the above-disclosed storage medium embodiment, the power frequency magnetic field condition is a power frequency magnetic field condition with a magnetic field strength of 0.5 mT, and the test voltage is 1.15 times the nominal voltage.

[0073] Optionally, in any one of the above disclosed storage medium embodiments, the tQ calculation formula is tQ = [(n-n%10) * 1.6 + n%10] * t1 * 2;

[0074] Wherein, t1 is the time required for the value in the fast pulse counter to increase by 1; n is the value in the pulse frequency register, which is a hexadecimal number.

[0075] In any one of the above disclosed embodiments, the AC power meter can be a single-phase fee control smart power meter or a three-phase fee control smart power meter, and is not limited.

[0076] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the system and storage medium disclosed by the embodiments, since it corresponds to the method disclosed by the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0077] The terms "comprise", "contain" or any other variants thereof in the specification and claims of the present application are intended to cover non-exclusive inclusion, so that the process, method, product or device comprising a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, product or device. Without more limitations, the element defined by the statement "comprises one" does not exclude the presence of another identical element in the process, method, product or device comprising the element.

[0078] The skilled person can further realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be realized by electronic hardware, computer software or a combination of both. In order to clearly illustrate the interchangeability of hardware and software, the components and steps of the examples have been described in the above description in general terms. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0079] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein can be directly implemented by hardware, software modules executed by a processor, or a combination of both. The software modules can be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0080] For system embodiments, since they basically correspond to the method embodiments, they are described more simply, and the relevant parts refer to the part of the method embodiments. The above-described device embodiments are only illustrative, wherein the units described as separate components can or can not be physically separated, and the components displayed as units can or can not be physical units, i.e., can be located in one place or can be distributed to multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment scheme. Those skilled in the art can understand and implement without creative labor.

[0081] The above description of disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the embodiments of the present application. Therefore, the embodiments of the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for testing the power frequency magnetic field of an AC energy meter under no-load conditions, characterized in that, include: When the AC energy meter is placed under a preset power frequency magnetic field condition, a test voltage is applied to the AC energy meter to make the AC energy meter work normally. Read the value from the fast pulse counter and determine the time required for the value in the fast pulse counter to increment by 1; Read the value from the pulse frequency register; both the fast pulse counter and the pulse frequency register are components of the metering chip in an AC energy meter. Based on the time and the value in the pulse frequency register, calculate the time tQ required for the AC energy meter to generate one pulse; including: calculating the time tQ required for the AC energy meter to generate one pulse according to the formula tQ=[(nn%10)×1.6 + n%10]×t1×2; where t1 is the time required for the value in the fast pulse counter to increase by 1; n is the value in the pulse frequency register, which is a hexadecimal number; If tQ is greater than the preset time, the AC energy meter is deemed to have passed the no-load test of the power frequency magnetic field.

2. The no-load test method for the power frequency magnetic field of an AC energy meter according to claim 1, characterized in that, When conducting tests in accordance with metrological technical specifications, the power frequency magnetic field conditions are preset to a power frequency magnetic field strength of 0.5 mT, the test voltage is 1.1 times the nominal voltage, and the preset time is 20 times the theoretical start-up time.

3. The no-load test method for the power frequency magnetic field of an AC energy meter according to claim 1, characterized in that, When conducting tests in accordance with the State Grid Corporation's enterprise standards, the power frequency magnetic field conditions are preset to a power frequency magnetic field strength of 0.5 mT, the test voltage is 1.15 times the nominal voltage, and the preset time is 20 times the theoretical start-up time.

4. The no-load test method for the power frequency magnetic field of an AC energy meter according to claim 1, characterized in that, The AC energy meter is either a single-phase prepaid smart energy meter or a three-phase prepaid smart energy meter.

5. A no-load test system for the power frequency magnetic field of an AC energy meter, characterized in that, include: The voltage circuit is used to apply a test voltage to the AC energy meter when the AC energy meter is placed under a preset power frequency magnetic field condition, so that the AC energy meter can work normally. The control unit is used to read the value in the fast pulse counter and determine the time required for the value in the fast pulse counter to increment by 1; Read the value in the pulse frequency register; the fast pulse counter and the pulse frequency register are both components of the metering chip of the AC energy meter; calculate the time tQ required for the AC energy meter to generate one pulse based on the time and the value in the pulse frequency register; if tQ is greater than the preset time, the AC energy meter is deemed to have passed the no-load test of the power frequency magnetic field. The control unit is specifically used to calculate the time tQ required for the AC energy meter to generate one pulse according to the formula tQ=[(nn%10)×1.6 + n%10]×t1×2; where t1 is the time required for the value in the fast pulse counter to increase by 1; n is the value in the pulse frequency register, which is a hexadecimal number.

6. The AC energy meter power frequency magnetic field no-load test system according to claim 5, characterized in that, When conducting tests in accordance with metrological technical specifications, the power frequency magnetic field condition is a power frequency magnetic field condition with a magnetic field strength of 0.5 mT, the test voltage is 1.1 times the nominal voltage, and the preset time is 20 times the theoretical start-up time.

7. The AC energy meter power frequency magnetic field no-load test system according to claim 5, characterized in that, When conducting tests in accordance with the State Grid Corporation of China's enterprise standards, the power frequency magnetic field condition is a power frequency magnetic field condition with a magnetic field strength of 0.5 mT, the test voltage is 1.15 times the nominal voltage, and the preset time is 20 times the theoretical start-up time.

8. A storage medium storing a program, characterized in that, When the AC energy meter is placed under a preset power frequency magnetic field condition and the AC energy meter is made to work normally by applying a test voltage, the method implemented by the program when executed by the processor includes: Read the value in the fast pulse counter and determine the time required for the value in the fast pulse counter to increase by 1; read the value in the pulse frequency register; the fast pulse counter and the pulse frequency register are both components of the metering chip of the AC energy meter; calculate the time tQ required for the AC energy meter to generate one pulse based on the time and the value in the pulse frequency register; if tQ is greater than the preset time, the AC energy meter is deemed to have passed the no-load test of the power frequency magnetic field. The step of calculating the time tQ required for the AC energy meter to generate one pulse based on the time and the value in the pulse frequency register includes: calculating the time tQ required for the AC energy meter to generate one pulse according to the formula tQ=[(nn%10)×1.6 + n%10]×t1×2; where t1 is the time required for the value in the fast pulse counter to increase by 1; and n is the value in the pulse frequency register, which is a hexadecimal number.

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