Electric energy meter active power calibration method, electric energy meter and storage medium

Abstract

The invention relates to the technical field of electric energy meters, in particular to an electric energy meter active power calibration method, an electric energy meter and a storage medium. The electric energy meter active power calibration method comprises the following steps: firstly, acquiring a first magnetic flux density of an environment where an electric energy meter is located and a second magnetic flux density generated by the electric energy meter, and determining whether the electric energy meter is interfered by an external magnetic field according to the first magnetic flux density and the second magnetic flux density; determining a calibration value according to the first magnetic flux density and a preset reference magnetic flux density under the condition of determining that the electric energy meter is interfered by the external magnetic field; and finally, correcting the sampled active power by using the calibration value to obtain the actual active power of the electric energy meter. Therefore, according to the electric energy meter active power calibration method provided by the invention, the corresponding calibration value can be determined according to the first magnetic flux density of the current environment so as to correct the active power sampled by the electric energy meter, so that the actual active power recorded by the electric energy meter is more accurate.

Description

Technical Field

[0001] The present application relates to the technical field of electric energy meters, and in particular, to a method for calibrating the active power of an electric energy meter, an electric energy meter, and a storage medium. Background Art

[0002] An electric energy meter is a key instrument for trade settlement and energy consumption monitoring in the power system, and is mainly used to measure the active power of the accumulated electric energy. However, in some application scenarios, if a constant magnetic field is applied outside the electric energy meter, thereby disturbing the current transformer or transformer inside the electric energy meter through the externally applied constant magnetic field, the magnetic core of the current transformer or transformer may reach deep saturation within 1 to 10 power frequency cycles. The current transformer will cause abnormal output of the sampled current on the secondary side due to the interference of the external constant magnetic field, and the transformer will also cause abnormal output voltage due to the interference of the external constant magnetic field, thus affecting the normal operation of the electric energy meter and making the active power recorded by the electric energy meter inaccurate, so as to achieve the purpose of stealing electricity. Summary of the Invention

[0003] The present application provides a method for calibrating the active power of an electric energy meter, an electric energy meter, and a storage medium, so as to solve the technical problem that the active power recorded by the electric energy meter in the related art is not accurate enough.

[0004] In a first aspect, the present application provides a method for calibrating the active power of an electric energy meter, and the method includes: Obtaining a first magnetic flux density in the environment where the electric energy meter is located and a second magnetic flux density generated by the electric energy meter itself; Determining whether the electric energy meter is interfered by an external magnetic field according to the first magnetic flux density and the second magnetic flux density; When it is determined that the electric energy meter is interfered by an external magnetic field, determining a calibration value according to the first magnetic flux density and a preset reference magnetic flux density; Using the calibration value to correct the sampled active power to obtain the actual active power of the electric energy meter.

[0005] In a possible design, the determining the calibration value according to the first magnetic flux density and the preset reference magnetic flux density includes: Determining a first deviation amplitude of the first magnetic flux density relative to the reference magnetic flux density; Determining a first correction coefficient corresponding to the first deviation amplitude according to the corresponding relationship between the deviation amplitude and the correction coefficient; Obtaining a calibration reference value preset when the electric energy meter leaves the factory, and determining the calibration value corresponding to the first magnetic flux density according to the first correction coefficient and the calibration reference value.

[0006] In a possible design, determining the first deviation amplitude of the first magnetic flux density relative to the reference magnetic flux density, and determining the first correction coefficient corresponding to the first deviation amplitude according to the corresponding relationship between the deviation amplitude and the correction coefficient includes: When Bref*100% > Bsum ≥ Bref*90%, the corresponding first correction coefficient is 8.3 - 10.0; When Bref*90% > Bsum ≥ Bref*80%, the corresponding first correction coefficient is 6.7 - 8.2; When Bref*80% > Bsum ≥ Bref*70%, the corresponding first correction coefficient is 5.3 - 6.6; When Bref*70% > Bsum ≥ Bref*60%, the corresponding first correction coefficient is 4.1 - 5.2; When Bref*60% > Bsum ≥ Bref*50%, the corresponding first correction coefficient is 3.1 - 4.0; When Bref*50% > Bsum ≥ Bref*40%, the corresponding first correction coefficient is 2.3 - 3.0; When Bref*40% > Bsum ≥ Bref*30%, the corresponding first correction coefficient is 1.7 - 2.2; When Bref*30% > Bsum ≥ Bref*20%, the corresponding first correction coefficient is 1.3 - 1.6; When Bref*20% > Bsum ≥ Bref*10%, the corresponding first correction coefficient is 1.1 - 1.2; Wherein, Bref is the reference magnetic flux density, and Bsum is the first magnetic flux density.

[0007] In a possible design, obtaining the calibration reference value preset when the electricity meter leaves the factory includes: Under the condition of nominal voltage, nominal current and power factor of 1, calculate according to the following formula: P gain =-err / (1 + err) Wherein, err is the initial error, and the absolute value of err is less than 1; When P gain ≥0, Err[0]=INT[P gain *2 15 ; When P gain <0, Err[0]=INT[2 16 +P gain *2 15 ; Wherein, Err[0] is the calibration reference value.

[0008] In a possible design, determining the calibration value corresponding to the first magnetic flux density according to the first correction factor and the calibration reference value includes: Taking the product of the first correction factor and the calibration reference value as the calibration value corresponding to the first magnetic flux density.

[0009] In a possible design, determining whether the electricity meter is interfered by an external magnetic field according to the first magnetic flux density and the second magnetic flux density includes: When the first magnetic flux density is greater than the second magnetic flux density, determining that the electricity meter is interfered by an external magnetic field.

[0010] In a possible design, obtaining the first magnetic flux density of the environment where the electricity meter is located and the second magnetic flux density generated by the electricity meter itself includes: Sampling the first magnetic flux density of the environment where the electricity meter is located by using a Hall sensor, and calculating the second magnetic flux density generated by the electricity meter itself according to the following formula: Bin =μ0*μr (N1*I1−N2*I2) / L where Bin is the second magnetic flux density generated by the electricity meter itself, μ0 is the magnetic permeability of vacuum, μr is the relative magnetic permeability of the magnetic core material, N1 is the number of turns of the primary winding, I1 is the primary current value, N2 is the number of turns of the secondary winding, I2 is the secondary current value, and L is the magnetic path length.

[0011] In a possible design, the method includes: when it is determined that the electricity meter is interfered by an external magnetic field, obtaining external magnetic field interference related data to generate an external magnetic field interference event, and storing the external magnetic field interference event; and / or, sending the external magnetic field interference event to a cloud platform, where the cloud platform is used to send a warning message to a user terminal or the electricity meter.

[0012] In a second aspect, the present application further provides an electricity meter, which includes: An acquisition unit, configured to acquire the first magnetic flux density of the environment where the electricity meter is located and the second magnetic flux density generated by the electricity meter itself; A first processing unit, configured to determine whether the electricity meter is interfered by an external magnetic field according to the first magnetic flux density and the second magnetic flux density; A second processing unit, configured to determine a calibration value according to the first magnetic flux density and a preset reference magnetic flux density when it is determined that the electricity meter is interfered by an external magnetic field; A correction unit, configured to correct the sampled active power by using the calibration value to obtain the actual active power of the electricity meter.

[0013] In a third aspect, the present application also provides a storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the active power calibration method for an electric energy meter as described in any one of the above.

[0014] Through the active power calibration method for an electric energy meter provided in the first aspect above, first, the first magnetic flux density of the environment where the electric energy meter is located and the second magnetic flux density generated by the electric energy meter itself are obtained, and it is determined whether the electric energy meter is interfered by an external magnetic field according to the first magnetic flux density and the second magnetic flux density; then, when it is determined that the electric energy meter is interfered by an external magnetic field, a calibration value is determined according to the first magnetic flux density and a preset reference magnetic flux density; finally, the sampled active power is corrected by using the calibration value to obtain the actual active power of the electric energy meter. In this way, according to the active power calibration method for an electric energy meter provided by the present application, a corresponding calibration value can be determined according to the first magnetic flux density of the current environment to correct the active power sampled by the electric energy meter, so that the actual active power recorded by the electric energy meter is more accurate.

[0015] For what is provided in the second aspect above and each possible design of the second aspect, the beneficial effects can refer to the beneficial effects brought by the first aspect above and each possible implementation manner of the first aspect, which will not be elaborated here. Description of the Drawings

[0016] Figure 1 It is a schematic flowchart of the active power calibration method for an electric energy meter provided by an embodiment of the present application; Figure 2 It is a schematic flowchart of the calibration value determination method provided by an embodiment of the present application; Figure 3 It is a schematic structural diagram of an electric energy meter provided by an embodiment of the present application. Detailed Embodiments

[0017] In the present application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one (item)" or a similar expression thereof refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, at least one (item) of a alone, b alone, or c alone can represent: a alone, b alone, c alone, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b, and c, where a, b, and c can be single or multiple. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0018] The orientation or positional relationship indicated by terms such as "center", "longitudinal", "lateral", "upper", "lower", "left", "right", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present application.

[0019] The terms "connected" and "coupled" should be understood in a broad sense. For example, the "connection" or "coupling" of a circuit structure can refer not only to a physical connection, but also to an electrical connection or a signal connection. For example, it can be a direct connection, that is, a physical connection, or it can be indirectly connected through at least one intermediate component, as long as the circuit is connected. It can also be the internal connection of two components; the signal connection can refer not only to the signal connection through a circuit, but also to the signal connection through a media medium, such as radio waves. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0020] In the related art, some illegal users use an external constant magnetic field to interfere with the electricity meter, resulting in abnormalities in the current transformer or transformer inside the electricity meter, thereby affecting the normal operation of the electricity meter to achieve the purpose of stealing electricity. For example, in one case, the electricity meter is usually powered by the output of the current transformer and the transformer. The external constant magnetic field will affect the abnormal operation of the current transformer or transformer inside the electricity meter, so that the magnetic core of the current transformer or transformer may reach deep saturation within 1 to 10 power frequency cycles (i.e., 20 to 200 ms). In this way, the current transformer will cause abnormal output of the sampled current on the secondary side due to external constant magnetic field interference, and the transformer will cause abnormal output voltage due to external constant magnetic field interference, resulting in the inability to supply normal power to the electricity meter, thereby causing errors in the active power recorded by the electricity meter to exceed the tolerance or abnormal power supply, etc., and finally achieving the purpose of stealing electricity.

[0021] In order to overcome the above defects in the related art, the present application provides a method for calibrating the active power of an electricity meter. First, obtain the first magnetic flux density of the environment where the electricity meter is located and the second magnetic flux density generated by the electricity meter itself, and determine whether the electricity meter is interfered by an external magnetic field according to the first magnetic flux density and the second magnetic flux density; then, when it is determined that the electricity meter is interfered by an external magnetic field, determine the calibration value according to the first magnetic flux density and a preset reference magnetic flux density; finally, use the calibration value to correct the sampled active power to obtain the actual active power of the electricity meter. In this way, according to the method for calibrating the active power of the electricity meter provided by the present application, the corresponding calibration value can be determined according to the first magnetic flux density of the current environment to correct the active power sampled by the electricity meter, so that the actual active power recorded by the electricity meter is more accurate.

[0022] Figure 1 The following is a schematic flow chart of the active power calibration method for the electric energy meter provided by the embodiments of this application. Please refer to Figure 1 As shown, the active power calibration method for the electric energy meter provided by this embodiment includes: S101. Obtain the first magnetic flux density of the environment where the electric energy meter is located and the second magnetic flux density generated by the electric energy meter itself.

[0023] In some embodiments, a Hall sensor can be set at the current transformer inside the electric energy meter, and the output end of the Hall sensor is connected to the IO interface of the single-chip microcomputer or the processor with AD (Analog-to-Digital Sampling) sampling, so as to convert the first magnetic flux density of the environment where the electric energy meter is located sampled by the Hall sensor into an analog signal and output it to the single-chip microcomputer or the processor.

[0024] Among them, the second magnetic flux density generated by the electric energy meter itself is specifically the magnetic flux density generated by the current transformer inside the ammeter, and the second magnetic flux density generated by the current transformer is determined by its own hardware parameters.

[0025] Exemplarily, in one embodiment, the second magnetic flux density generated by the electric energy meter itself can be calculated according to the following formula (1): Bin =μ0*μr (N1*I1−N2*I2) / L(1) Among them, Bin is the second magnetic flux density generated by the electric energy meter itself, μ0 is the magnetic permeability of vacuum, generally, μ0 = 4π×10 −7 , μr is the relative magnetic permeability of the magnetic core material, N1 is the number of turns of the primary winding, I1 is the primary current value, N2 is the number of turns of the secondary winding, I2 is the secondary current value, and L is the magnetic path length.

[0026] Among them, the first magnetic flux density of the environment where the electric energy meter is located is composed of the magnetic flux density generated by the externally applied constant magnetic field and the second magnetic flux density generated by the current transformer itself. The magnetic flux density generated by the externally applied constant magnetic field can be expressed as Bout, the first magnetic flux density can be expressed as Bsum, and the second magnetic flux density generated by the current transformer can be expressed as Bin. Then the relationship among the three can be expressed as: Bsum = Bout + Bin.

[0027] S102. Determine whether the electric energy meter is interfered by an external magnetic field according to the first magnetic flux density and the second magnetic flux density.

[0028] In one embodiment, when it is determined that the first magnetic flux density Bsum is greater than the second magnetic flux density Bin, it is determined that the electric energy meter is interfered by an external magnetic field.

[0029] It can be understood that when the electric energy meter is not interfered by an external constant magnetic field in the current environment, the sampled first magnetic flux density Bsum is equal to the second magnetic flux density Bin. When the first magnetic flux density Bsum is greater than the second magnetic flux density Bin, it can be determined that there is an external constant magnetic field in the current environment where the electric energy meter is located. Therefore, it can be determined that the electric energy meter is interfered by an external magnetic field.

[0030] Generally, when the electric energy meter is working, the live wire voltage V1 is 220V, and the secondary side voltage V2 output by the transformer in the electric energy meter is 15V. The secondary side voltage V2 output by the transformer supplies power to the electric energy meter.

[0031] In one embodiment, when the electric energy meter is interfered by an external magnetic field, the voltage V2 at the output end of the secondary side of the transformer will decrease. When the voltage V2 at the output end of the secondary side of the transformer is greater than 7.5V, dynamic error compensation is performed on the electric energy meter.

[0032] In one embodiment, the judgment period T1 for the secondary side voltage V2 is 100us; the judgment period T2 for the first magnetic flux density Bsum is 1ms.

[0033] S103. When it is determined that the electric energy meter is interfered by an external magnetic field, determine the calibration value according to the first magnetic flux density and a preset reference magnetic flux density.

[0034] Figure 2 For the schematic flow chart of the calibration value determination method provided by the embodiments of the present application, please refer to Figure 2 As shown, in one embodiment, determining the calibration value according to the first magnetic flux density and a preset reference magnetic flux density specifically includes: S201. Determine the first deviation amplitude of the first magnetic flux density relative to the reference magnetic flux density.

[0035] In one embodiment, according to the influence degree of the magnetic flux on the active power sampled by the electric energy meter, a reference magnetic flux density can be first set, and then the corresponding correction coefficient is determined according to the first deviation amplitude of the first magnetic flux density relative to the reference magnetic flux density.

[0036] It can be understood that for the convenience of calibrating the electric energy meter, piecewise calibration is performed in this embodiment, that is, it is determined that the first magnetic flux density falls into different segmented intervals of the reference magnetic flux density, and then different correction coefficients are used for correction.

[0037] Among them, the first deviation amplitude of the first magnetic flux density relative to the reference magnetic flux density can also be understood as the ratio of the first magnetic flux density to the reference magnetic flux density.

[0038] S202. According to the corresponding relationship between the deviation amplitude and the correction coefficient, determine the first correction coefficient corresponding to the first deviation amplitude.

[0039] In one embodiment, based on the empirical values of technicians and the data accumulated over a long time for analysis, the corresponding relationship between the deviation amplitude and the correction coefficient can be determined. In this way, after determining the first deviation amplitude of the first magnetic flux density relative to the reference magnetic flux density, the first correction coefficient corresponding to the first deviation amplitude can be determined according to the corresponding relationship between the deviation amplitude and the correction coefficient.

[0040] In one embodiment, to determine the first deviation amplitude of the first magnetic flux density relative to the reference magnetic flux density and determine the first correction coefficient corresponding to the first deviation amplitude according to the corresponding relationship between the deviation amplitude and the correction coefficient, it specifically includes: When Bref*100% > Bsum ≥ Bref*90%, the corresponding first correction coefficient is 8.3 - 10.0, and the value corresponding to the first correction coefficient at this time can be expressed as k[1]; When Bref*90% > Bsum ≥ Bref*80%, the corresponding first correction coefficient is 6.7 - 8.2, and the value corresponding to the first correction coefficient at this time can be expressed as k[2]; When Bref*80% > Bsum ≥ Bref*70%, the corresponding first correction coefficient is 5.3 - 6.6, and the value corresponding to the first correction coefficient at this time can be expressed as k[3]; When Bref*70% > Bsum ≥ Bref*60%, the corresponding first correction coefficient is 4.1 - 5.2, and the value corresponding to the first correction coefficient at this time can be expressed as k[4]; When Bref*60% > Bsum ≥ Bref*50%, the corresponding first correction coefficient is 3.1 - 4.0, and the value corresponding to the first correction coefficient at this time can be expressed as k[5]; When Bref*50% > Bsum ≥ Bref*40%, the corresponding first correction coefficient is 2.3 - 3.0, and the value corresponding to the first correction coefficient at this time can be expressed as k[6]; When Bref*40% > Bsum ≥ Bref*30%, the corresponding first correction coefficient is 1.7 - 2.2, and the value corresponding to the first correction coefficient at this time can be expressed as k[7]; When Bref*30% > Bsum ≥ Bref*20%, the corresponding first correction coefficient is 1.3 - 1.6, and the value corresponding to the first correction coefficient at this time can be expressed as k[8]; When Bref*20% > Bsum ≥ Bref*10%, the corresponding first correction coefficient is 1.1 - 1.2, and the value corresponding to the first correction coefficient at this time can be expressed as k[9].

[0041] Since the electricity meter itself has the ability to resist magnetic fields during movement, when the externally applied magnetic field is weak, there is no need to calibrate the electricity meter. For example, when it is detected that Bref * 10% > Bsum ≥ 0, there is no need to calibrate the electricity meter in this embodiment.

[0042] It can be understood that when the first magnetic flux density falls within different reference magnetic flux density interval values, the corresponding values of the first correction coefficient are different. Therefore, the first correction coefficient provided in this embodiment is also an interval value. When the specific ratio of the first magnetic flux density to the reference magnetic flux density is different, different values can be taken within the interval value corresponding to the first correction coefficient; and when the specific ratio of the first magnetic flux density to the reference magnetic flux density is larger, the value taken by the first correction coefficient is also larger.

[0043] S203. Obtain the calibration reference value preset when the electricity meter leaves the factory, and determine the calibration value corresponding to the first magnetic flux density according to the first correction coefficient and the calibration reference value.

[0044] In one embodiment, obtaining the calibration reference value preset when the electricity meter leaves the factory specifically includes: Under the condition of nominal voltage (220V), nominal current 100% Ib (5A), and power factor of 1, calculate according to the following formula (2): P gain =-err / (1 + err) (2) where err is the initial error, and technicians can set the initial error according to empirical values. Generally, the absolute value of err is less than 1; when P gain ≥0, Err[0]=INT[P gain *2 15 ; when P gain <0, Err[0]=INT[2 16 +P gain *2 15 ; where Err[0] is the calibration reference value, and INT[] is the rounding-down function, representing the rounding-down operation.

[0045] It can be seen that the calibration reference value Err[0] of the electricity meter can be determined through the above method, and then the product of the determined first correction coefficient and the calibration reference value Err[0] is used as the calibration value corresponding to the first magnetic flux density.

[0046] S104. Correct the sampled active power using the calibration value to obtain the actual active power of the electricity meter.

[0047] It is understandable that there are registers and a single-chip microcomputer in the electric energy meter. The single-chip microcomputer can process the above data processing process, then write the obtained calibration value into the register, and then the single-chip microcomputer can read the calibration value from the register to calibrate the recorded active power to obtain the actual active power of the electric energy meter.

[0048] Specifically, in this embodiment, the product of the sampled active power and the calibration value can be used as the actual active power of the electric energy meter.

[0049] In one embodiment, the processing flow inside the single-chip microcomputer or other processing chips includes: 1. ADC Sampling and Acquisition of Original Data The metering chip converts the analog signals of the current and voltage channels through an ADC (Analog-to-Digital Converter) into digital signals and outputs them as original sampling values (such as 16-bit signed numbers).

[0050] 2. Application of Gain Correction Value Multiplication operation: The digital signal processing unit inside the metering chip multiplies the original sampling value output by the ADC by the calibration value in the correction register to correct the amplitude error. The calibration process can be expressed by the formula: corrected sampling value = original sampling value × correction value; for example, multiplying the original sampled voltage value by the calibration value to obtain the corrected voltage value, and multiplying the original sampled current value by the calibration value to obtain the corrected current value.

[0051] 3. Active Power Calculation Instantaneous power calculation: The corrected current and voltage sampling values are multiplied to obtain the instantaneous power: Pinst = V3 × I3; V3 is the corrected voltage value obtained by using the above correction method, and I3 is the corrected current value obtained by using the above correction method.

[0052] Integration and filtering: The metering chip performs low-pass filtering and integration on the instantaneous power to obtain the average active power, and finally outputs it as an electric energy pulse or a digital register value.

[0053] According to the calibration method provided in this embodiment, when there is external magnetic field interference, it will affect the normal current sampling of the current transformer. After the current sampling is affected, the electric energy measurement will deviate, enabling users to achieve the purpose of stealing electricity. By correcting the value of the calibration register of the metering chip, the accuracy of the electric energy measurement of the electric energy meter can meet the requirements.

[0054] In one embodiment, when it is determined that the electricity meter is interfered by an external magnetic field, relevant data related to the external magnetic field interference is obtained to generate an external magnetic field interference event, and the external magnetic field interference event is stored, so as to facilitate subsequent viewing of the magnetic field interference event by the user. Among them, obtaining relevant data related to the external magnetic field interference may include the magnetic field intensity, the corresponding calibration value, etc., and the magnetic field interference event generally includes information such as the start time, end time, location, and device number of the magnetic interference occurrence, so as to facilitate subsequent viewing and event traceability.

[0055] In one embodiment, when it is determined that the electricity meter is interfered by an external magnetic field, relevant data related to the external magnetic field interference is obtained to generate an external magnetic field interference event, and the external magnetic field interference event can also be sent to the cloud platform, and the cloud platform is used to send a warning message to the user terminal or the electricity meter. For example, the cloud platform can send a warning message to the management terminal of the electricity meter management user to prompt the user to handle the abnormal situation in time and avoid continuous magnetic interference.

[0056] In one embodiment, when it is detected that the first magnetic flux density Bsum = the second magnetic flux density Bin, it is determined that the magnetic field interference has been lifted, and the relevant data of the magnetic field interference event is saved to facilitate subsequent viewing and event traceability.

[0057] The following provides an electricity meter, and the electricity meter provided below can be referred to correspondingly with the active power calibration method of the electricity meter provided in the above embodiments.

[0058] Figure 3 For the structural schematic diagram of the electricity meter provided by the embodiments of the present application, please refer to Figure 3 As shown, the electricity meter provided in this embodiment includes: an acquisition unit 301, a first processing unit 302, a second processing unit 303, and a correction unit 304; among them, the acquisition unit 301 is used to acquire the first magnetic flux density of the environment where the electricity meter is located and the second magnetic flux density generated by the electricity meter itself; the first processing unit 302 is used to determine whether the electricity meter is interfered by an external magnetic field according to the first magnetic flux density and the second magnetic flux density; the second processing unit 303 is used to determine a calibration value according to the first magnetic flux density and a preset reference magnetic flux density when it is determined that the electricity meter is interfered by an external magnetic field; the correction unit 304 is used to correct the sampled active power with the calibration value to obtain the actual active power of the electricity meter.

[0059] In one embodiment, the second processing unit 303 is specifically used to: determine the first deviation amplitude of the first magnetic flux density relative to the reference magnetic flux density; determine the first correction coefficient corresponding to the first deviation amplitude according to the corresponding relationship between the deviation amplitude and the correction coefficient; obtain the calibration reference value preset when the electricity meter leaves the factory, and determine the calibration value corresponding to the first magnetic flux density according to the first correction coefficient and the calibration reference value.

[0060] In one embodiment, the second processing unit 303 is further specifically configured to: When Bref*100% > Bsum ≥ Bref*90%, determine that the corresponding first correction coefficient is 8.3 to 10.0; When Bref*90% > Bsum ≥ Bref*80%, determine that the corresponding first correction coefficient is 6.7 to 8.2; When Bref*80% > Bsum ≥ Bref*70%, determine that the corresponding first correction coefficient is 5.3 to 6.6; When Bref*70% > Bsum ≥ Bref*60%, determine that the corresponding first correction coefficient is 4.1 to 5.2; When Bref*60% > Bsum ≥ Bref*50%, determine that the corresponding first correction coefficient is 3.1 to 4.0; When Bref*50% > Bsum ≥ Bref*40%, determine that the corresponding first correction coefficient is 2.3 to 3.0; When Bref*40% > Bsum ≥ Bref*30%, determine that the corresponding first correction coefficient is 1.7 to 2.2; When Bref*30% > Bsum ≥ Bref*20%, determine that the corresponding first correction coefficient is 1.3 to 1.6; When Bref*20% > Bsum ≥ Bref*10%, determine that the corresponding first correction coefficient is 1.1 to 1.2; Wherein, Bref is the reference magnetic flux density and Bsum is the first magnetic flux density.

[0061] In one embodiment, the second processing unit 303 is further specifically configured to: Under the condition of nominal voltage, nominal current and power factor of 1, calculate according to the following formula: P gain =-err / (1 + err) Wherein, err is the initial error and the absolute value of err is less than 1; When P gain ≥0, Err[0]=INT[P gain *2 15 ; when P gain <0, Err[0]=INT[2 16 +P gain *2 15 ; Wherein, Err[0] is the calibration reference value.

[0062] In one embodiment, the second processing unit 303 is further specifically configured to: use the product of the first correction coefficient and the calibration reference value as the calibration value corresponding to the first magnetic flux density.

[0063] In one embodiment, the first processing unit 302 is specifically configured to: determine that the electricity meter is interfered by an external magnetic field when the first magnetic flux density is greater than the second magnetic flux density.

[0064] In one embodiment, the acquisition unit 301 is specifically configured to: sample the first magnetic flux density of the environment where the electricity meter is located by using a Hall sensor, and calculate the second magnetic flux density generated by the electricity meter itself according to the following formula: Bin =μ0*μr (N1*I1−N2*I2) / L where Bin is the second magnetic flux density generated by the electricity meter itself, μ0 is the magnetic permeability of vacuum, μr is the relative magnetic permeability of the magnetic core material, N1 is the number of turns of the primary winding, I1 is the primary current value, N2 is the number of turns of the secondary winding, I2 is the secondary current value, and L is the magnetic path length.

[0065] In one embodiment, the electricity meter further includes an event generation module, and the event generation module is configured to: when it is determined that the electricity meter is interfered by an external magnetic field, obtain external magnetic field interference related data to generate an external magnetic field interference event, and store the external magnetic field interference event; and / or, send the external magnetic field interference event to the cloud platform, and the cloud platform is configured to send a warning message to the user terminal or the electricity meter.

[0066] It can be seen that according to the electricity meter provided in this embodiment, it can actively monitor whether it is interfered by an external magnetic field, and when it is monitored that it is interfered by an external magnetic field, it can automatically generate a corresponding calibration value to correct the active power sampled by the electricity meter, so that the actual active power recorded by the electricity meter is more accurate. In addition, when it is interfered by an external magnetic field, a corresponding magnetic field interference event can be generated to facilitate subsequent viewing and event tracing; or the external magnetic field interference event can be sent to the cloud platform, and the cloud platform can send a warning message to the management terminal of the electricity meter management user to prompt the user to process the abnormal situation in time and avoid continuous magnetic interference.

[0067] It should be noted that the above functional modules are only exemplary descriptions and not all the structures of the electricity meter. The electricity meter may further include other circuit structures, such as current transformers, transformers, Hall sensors, registers, communication modules, and power supplies and other hardware, which will not be elaborated here.

[0068] An embodiment of the present application further provides a storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the active power calibration method for an electric energy meter provided in the above embodiment.

[0069] Finally, it should be noted that the above embodiments are only specific implementation manners of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for calibrating the active power of an electric energy meter, characterized in that, The method includes: Obtaining a first magnetic flux density of the environment where the electric energy meter is located and a second magnetic flux density generated by the electric energy meter itself; Determining whether the electric energy meter is interfered by an external magnetic field according to the first magnetic flux density and the second magnetic flux density; When it is determined that the electric energy meter is interfered by an external magnetic field, determining a calibration value according to the first magnetic flux density and a preset reference magnetic flux density; Using the calibration value to correct the sampled active power to obtain the actual active power of the electric energy meter.

2. The active power calibration method of the electric energy meter according to claim 1, characterized in that The determining the calibration value according to the first magnetic flux density and the preset reference magnetic flux density includes: Determining a first deviation amplitude of the first magnetic flux density relative to the reference magnetic flux density; Determining a first correction coefficient corresponding to the first deviation amplitude according to the corresponding relationship between the deviation amplitude and the correction coefficient; Obtaining a calibration reference value preset when the electric energy meter leaves the factory, and determining the calibration value corresponding to the first magnetic flux density according to the first correction coefficient and the calibration reference value.

3. The method for calibrating the active power of an electric energy meter according to claim 2, wherein The determining the first deviation amplitude of the first magnetic flux density relative to the reference magnetic flux density and determining the first correction coefficient corresponding to the first deviation amplitude according to the corresponding relationship between the deviation amplitude and the correction coefficient includes: When Bref*100% > Bsum ≥ Bref*90%, the corresponding first correction coefficient is 8.3 - 10.0; When Bref*90% > Bsum ≥ Bref*80%, the corresponding first correction coefficient is 6.7 - 8.2; When Bref*80% > Bsum ≥ Bref*70%, the corresponding first correction coefficient is 5.3 - 6.6; When Bref*70% > Bsum ≥ Bref*60%, the corresponding first correction coefficient is 4.1 - 5.2; When Bref*60% > Bsum ≥ Bref*50%, the corresponding first correction coefficient is 3.1 - 4.0; When Bref*50% > Bsum ≥ Bref*40%, the corresponding first correction coefficient is 2.3 - 3.0; When Bref*40% > Bsum ≥ Bref*30%, the corresponding first correction coefficient is 1.7 - 2.2; When Bref*30% > Bsum ≥ Bref*20%, the corresponding first correction coefficient is 1.3 - 1.6; When Bref*20% > Bsum ≥ Bref*10%, the corresponding first correction coefficient is 1.1 - 1.2; Wherein, Bref is the reference magnetic flux density, and Bsum is the first magnetic flux density.

4. The method for calibrating the active power of an electric energy meter according to claim 2 or 3, characterized in that The obtaining the calibration reference value preset when the electric energy meter leaves the factory includes: Calculating according to the following formula under the condition of rated voltage, rated current and power factor of 1: P gain = -err / (1 + err) Wherein, err is the initial error, and the absolute value of err is less than 1; When P gain ≥ 0, Err[0] = INT[P gain * 2 15 ; When P gain < 0, Err[0] = INT[2 16 + P gain * 2 15 ; Wherein, Err[0] is the calibration reference value.

5. The active power calibration method of the electric energy meter according to claim 4, characterized in that The determining the calibration value corresponding to the first magnetic flux density according to the first correction coefficient and the calibration reference value includes: Taking the product of the first correction coefficient and the calibration reference value as the calibration value corresponding to the first magnetic flux density.

6. The active power calibration method of the electric energy meter according to claim 1, characterized in that, Determining whether the watt-hour meter is interfered by an external magnetic field according to the first magnetic flux density and the second magnetic flux density includes: When the first magnetic flux density is greater than the second magnetic flux density, determining that the watt-hour meter is interfered by an external magnetic field.

7. The method for calibrating the active power of an electric energy meter according to claim 1, characterized in that Obtaining the first magnetic flux density of the environment where the watt-hour meter is located and the second magnetic flux density generated by the watt-hour meter itself includes: Sampling the first magnetic flux density of the environment where the watt-hour meter is located by using a Hall sensor, and calculating the second magnetic flux density generated by the watt-hour meter itself according to the following formula: Bin =μ0*μr (N1*I1−N2*I2) / L where Bin is the second magnetic flux density generated by the watt-hour meter itself, μ0 is the magnetic permeability of vacuum, μr is the relative magnetic permeability of the magnetic core material, N1 is the number of turns of the primary winding, I1 is the primary current value, N2 is the number of turns of the secondary winding, I2 is the secondary current value, and L is the magnetic path length.

8. The active power calibration method of the electric energy meter according to claim 1, characterized in that The method includes: when it is determined that the watt-hour meter is interfered by an external magnetic field, obtaining data related to the external magnetic field interference to generate an external magnetic field interference event, and storing the external magnetic field interference event; and / or, sending the external magnetic field interference event to a cloud platform, where the cloud platform is used to send a warning message to a user terminal or the watt-hour meter.

9. An electric energy meter, characterized in that, Including: An obtaining unit, configured to obtain the first magnetic flux density of the environment where the watt-hour meter is located and the second magnetic flux density generated by the watt-hour meter itself; A first processing unit, configured to determine whether the watt-hour meter is interfered by an external magnetic field according to the first magnetic flux density and the second magnetic flux density; A second processing unit, configured to determine a calibration value according to the first magnetic flux density and a preset reference magnetic flux density when it is determined that the watt-hour meter is interfered by an external magnetic field; A correction unit, configured to correct the sampled active power by using the calibration value to obtain the actual active power of the watt-hour meter.

10. A storage medium, characterized in that, A computer program is stored on the storage medium, and when the computer program is executed by a processor, the active power calibration method of the watt-hour meter according to any one of claims 1 to 8 is implemented.

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