An anti-interference method, system, terminal device and storage medium for electric energy metering products

Abstract

This invention discloses an anti-interference method, system, terminal device, and storage medium for electricity metering products. The method includes: acquiring the first position, first magnetic field strength, magnetic field direction, vacuum permeability, second position, current element length, current element direction, third position, coil radius, and sampling data of the metering product to be output; calculating the angle between the metering product to be output and the current element to be measured based on the first position, second position, magnetic field direction, and current element direction; calculating the induced current generated by the current sampling element based on the first magnetic field strength, first position, second position, third position, current element length, vacuum permeability, coil radius, and the angle; and performing compensation calculations based on the sampling data and the induced current to obtain the metering current of the metering product to be output. By implementing this invention, the anti-interference capability of the metering product is improved.

Description

Technical Field

[0001] This invention relates to the field of current sampling technology, and in particular to an anti-interference method, system, terminal equipment, and storage medium for electricity metering products. Background Technology

[0002] Currently, electricity metering products on the market can be categorized into two types based on their installation method: built-in and external. External current sampling elements can include Rogowski coils, among others. With the gradual maturation of Rogowski coil current transformer technology, its application in electricity metering within the power industry is becoming increasingly widespread. Especially in applications with large dynamic current variations, many electrical devices have adopted Rogowski coils to replace current transformers (CTs) for large dynamic range current sampling. However, Rogowski coils are air-core coils without a magnetic core, making them susceptible to the influence of power frequency magnetic fields. When used as external current sampling elements in series with the circuit to detect current, Rogowski coils are easily affected by power frequency fluctuations, generating additional induced current and leading to significant metering errors in the metering products. Summary of the Invention

[0003] This invention provides an anti-interference method, system, terminal equipment, and storage medium for electricity metering products. It can effectively solve the problem that in the prior art, external current sampling elements connected in series in the circuit to detect current are easily affected by power frequency, resulting in additional induced current and large metering errors in the metering products.

[0004] An embodiment of the present invention provides an anti-interference method for electricity metering products, applicable to the microcontroller module of an anti-interference system for electricity metering products; the anti-interference method for electricity metering products includes:

[0005] Acquire the first position, first magnetic field strength, magnetic field direction, vacuum permeability, second position, current element length, current element direction, third position, coil radius, and sampling data of the product to be output and measured;

[0006] Based on the first position, the second position, the direction of the magnetic field, and the direction of the current element, the angle between the metering product to be output and the current element to be measured is calculated.

[0007] The induced current generated by the current sampling element is calculated based on the first magnetic field strength, the first position, the second position, the third position, the length of the current element, the vacuum permeability, the coil radius, and the included angle.

[0008] The metering current of the product to be output is obtained by performing compensation calculations based on the sampled data and the induced current.

[0009] Furthermore, the direction of the magnetic field is perpendicular to the direction of the current element;

[0010] Based on the first position, the second position, the direction of the magnetic field, and the direction of the current element, the angle between the output metering product and the measured current element is calculated, including:

[0011] A spatial rectangular coordinate system is constructed with the direction of the magnetic field as the horizontal axis and the direction of the current element as the vertical axis.

[0012] Based on the first position and the second position, the straight-line distance between the metering product to be output and the current element to be measured is calculated;

[0013] Based on the first position, the straight-line distance, and the spatial rectangular coordinate system, the angle between the metering product to be output and the current element to be measured is calculated.

[0014] Further, based on the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum permeability, the coil radius, and the included angle, the induced current generated by the current sampling element is calculated, including:

[0015] The current of the current element is calculated based on the first magnetic field strength, the first position, the second position, the length of the current element, the vacuum permeability, and the included angle.

[0016] The second magnetic field strength at the current sampling element is calculated based on the current of the current element, the second position, the third position, the length of the current element, and the vacuum permeability.

[0017] The induced current of the current sampling element is calculated based on the second magnetic field strength, the second position, the third position, the coil radius, and the vacuum permeability.

[0018] Furthermore, the metering product to be output is externally connected to the current sampling element.

[0019] Furthermore, the product to be output includes: a metering module, a magnetic detection module, and a microcontroller module; the metering module is connected to the current sampling element and the microcontroller module respectively; the magnetic detection module is connected to the microcontroller module.

[0020] The metering module is used to receive the sampling data from the current sampling element and the metering current from the microcontroller module, and to transmit the sampling data to the microcontroller module.

[0021] The magnetic detection module is used to detect the magnetic field to obtain the first magnetic field strength and magnetic field direction, and transmit the first magnetic field strength and magnetic field direction to the microcontroller module.

[0022] The microcontroller module is used to receive sampling data, the first magnetic field strength and the magnetic field direction, calculate the induced current and the metering current, and return the metering current to the metering module.

[0023] As an improvement to the above solution, another embodiment of the present invention provides an anti-interference system for electricity metering products, comprising:

[0024] The data acquisition module is used to acquire the first position, first magnetic field strength, magnetic field direction, vacuum permeability, second position, current element length, current element direction, third position, coil radius, and sampling data of the metering product to be output;

[0025] The metering angle calculation module is used to calculate the angle between the metering product to be output and the current element to be measured based on the first position, the second position, the direction of the magnetic field and the direction of the current element.

[0026] The induced current calculation module is used to calculate the induced current generated by the current sampling element based on the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum permeability, the coil radius, and the included angle.

[0027] The metering data output module is used to perform compensation calculations based on the sampled data and the induced current to obtain the metering current of the metering product to be output.

[0028] Furthermore, the direction of the magnetic field is perpendicular to the direction of the current element;

[0029] The metering angle calculation module is used to calculate the angle between the metering product to be output and the current element to be measured based on the first position, the second position, the direction of the magnetic field, and the direction of the current element, including:

[0030] The spatial coordinate system construction submodule is used to construct a spatial rectangular coordinate system with the direction of the magnetic field as the horizontal axis and the direction of the current element as the vertical axis.

[0031] The distance calculation submodule is used to calculate the straight-line distance between the metering product to be output and the current element to be measured based on the first position and the second position.

[0032] The included angle calculation submodule is used to calculate the included angle between the metering product to be output and the current element to be measured based on the first position, the straight-line distance, and the spatial rectangular coordinate system.

[0033] Further, the induced current calculation module is used to calculate the induced current generated by the current sampling element based on the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum permeability, the coil radius, and the included angle, including:

[0034] The current element current calculation submodule is used to calculate the current element current based on the first magnetic field strength, the first position, the second position, the current element length, the vacuum permeability, and the included angle.

[0035] The second magnetic field strength calculation submodule is used to calculate the second magnetic field strength at the current sampling element based on the current of the current element, the second position, the third position, the length of the current element, and the vacuum permeability.

[0036] The sampling element calculation submodule is used to calculate the induced current of the current sampling element based on the second magnetic field strength, the second position, the third position, the coil radius, and the vacuum permeability.

[0037] Another embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements an anti-interference method for an electricity metering product as described in the above embodiments.

[0038] Another embodiment of the present invention provides a computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to perform an anti-interference method for an electricity metering product as described in the above embodiment.

[0039] By implementing this invention, at least the following beneficial effects are achieved:

[0040] This invention provides an anti-interference method, system, terminal device, and storage medium for electricity metering products. The method is applicable to the microcontroller module of an anti-interference system for electricity metering products. It can acquire the first position, first magnetic field strength, magnetic field direction, vacuum permeability, second position, current element length, current element direction, third position, coil radius, and sampling data of the metering product to be output; calculate the angle between the metering product to be output and the current element to be measured based on the first position, second position, magnetic field direction, and current element direction; calculate the induced current generated by the current sampling element based on the first magnetic field strength, first position, second position, third position, current element length, vacuum permeability, coil radius, and the angle; and perform compensation calculations based on the sampling data and the induced current to obtain the metering current of the metering product to be output. By using parameters such as the angle between the metering product to be output and the current element to be measured, the induced current generated by the current sampling element can be calculated more accurately. Further compensation calculations can eliminate or reduce the error caused by the induced current generated by the current sampling element due to factors such as magnetic field interference and current fluctuations, thereby improving the anti-interference ability of the power metering product and improving the accuracy of the metering current. Attached Figure Description

[0041] Figure 1 This is a schematic flowchart of an anti-interference method for an electricity metering product provided in an embodiment of the present invention;

[0042] Figure 2 This is a schematic diagram of the structure of an anti-interference system for an energy metering product according to an embodiment of the present invention;

[0043] Figure 3 This is a schematic diagram of the anti-magnetic interference of a built-in metering product provided in an embodiment of the present invention;

[0044] Figure 4 This is a schematic diagram of an external metering product subjected to magnetic field interference according to an embodiment of the present invention;

[0045] Figure 5 This is a schematic diagram of a single-phase energy meter frame provided in an embodiment of the present invention;

[0046] Figure 6 This is a schematic diagram of the winding of a Rogowski coil according to an embodiment of the present invention;

[0047] Figure 7 This is a schematic diagram of the equivalent large number of turns of a Rogowski coil provided in an embodiment of the present invention;

[0048] Figure 8 This is a schematic diagram of an interference source generating a magnetic field according to an embodiment of the present invention;

[0049] Figure 9 This is a schematic diagram of the compensation scheme provided in an embodiment of the present invention;

[0050] Figure 10 This is a schematic diagram of the internal processing flow of an electricity meter according to an embodiment of the present invention. Detailed Implementation

[0051] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0052] See Figure 1 This is a flowchart illustrating an anti-interference method for an energy metering product according to an embodiment of the present invention. The anti-interference method is applicable to the microcontroller module of an energy metering product anti-interference system. The anti-interference method includes:

[0053] S1. Obtain the first position, first magnetic field strength, magnetic field direction, vacuum permeability, second position, current element length, current element direction, third position, coil radius, and sampling data of the product to be output and measured;

[0054] S2. Based on the first position, the second position, the direction of the magnetic field, and the direction of the current element, calculate the angle between the metering product to be output and the current element to be measured.

[0055] S3. Calculate the induced current generated by the current sampling element based on the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum permeability, the coil radius, and the included angle.

[0056] S4. Based on the sampled data and the induced current, a compensation calculation is performed to obtain the metering current of the product to be output.

[0057] Specifically, current sampling elements can be categorized into two types based on their installation method: internal and external. External current sampling elements can be open-ended current transformers or Rogowski coils, etc. In energy metering products with internal current sampling elements, because the current sampling element is internal and close to the metering circuit within the metering product, twisted-pair current lines are typically used to cancel magnetic field interference and improve the metering product's immunity to external magnetic field disturbances. Figure 3As shown. However, external current sampling elements are different because in external energy metering products, the current sampling element is located far from the metering circuit, such as... Figure 4 As shown, the magnetic field faced by the current sampling element at its beginning (metering product side) and end (coil side) will be attenuated (with the metering product as the center point). Adding to this the losses in the line (because the line distance can be as long as 0.5 meters), traditional built-in current compensation methods are not suitable for external systems.

[0058] Specifically, taking a single-phase energy meter as an example, the working principle of a Rogowski coil as an external current sampling element is explained. Figure 5 As shown, a single Rogowski coil energy meter includes an MCU (microcontroller unit), a single-phase metering chip, a voltage sampling circuit, a Rogowski coil, and a current sampling circuit. The Rogowski coil, acting as a current transformer, is connected in series in the circuit and is connected to the AD sampling terminal of the metering chip via the current sampling circuit. The metering chip is connected to the MCU via an SPI bus (serial peripheral interface). Compared to traditional current transformers or manganin sampling, using a Rogowski coil as the current transformer offers advantages such as a wide dynamic range, flexible installation, and uninterrupted installation, thus having broad application prospects. A current sensor is a device that detects current, sensing the measured current and converting it into an electrical signal that meets standard requirements according to a certain rule. There are two main types of current sensors: one is an iron-core coil transformer, which can be made in different sizes according to the rated current; its disadvantage is that the iron core exhibits magnetic saturation and nonlinearity, resulting in a narrow current measurement range. The other type is the Rogowski coil, which features a wide dynamic range, excellent linearity, small size, and low cost. Whether it's an iron-core coil current transformer or a Rogowski coil, these externally located current sampling elements are easily affected by power frequency, generating additional induced current and leading to significant measurement errors. Rogowski coils, in particular, are more susceptible to power frequency magnetic fields because they are air-core coils without a magnetic core.

[0059] like Figure 6 As shown, the small turns of the Rogowski coil are spirally wound tightly around the entire coil frame, forming an equivalent large turn along the winding direction (e.g., Figure 7 (As shown). The magnetic field B is perpendicular to the plane containing the large coil. As the magnetic field changes with time, the magnetic flux through the large coil changes accordingly, thus inducing an electromotive force e in the Rogowski coil. Although the large coil has only one turn, its area is usually much larger than the cross-sectional area of ​​the small coil. Even if the intensity of the perpendicular interfering magnetic field is similar to the magnetic induction intensity generated by the conductor under test, it will still introduce significant errors to the measurement results. Calculations show that the effect of the parallel magnetic field on the Rogowski coil is zero and can be ignored, so it will not be analyzed in detail here.

[0060] Table 1 shows the output voltage data of the Rogowski coil before and after being subjected to power frequency current interference:

[0061] Table 1

[0062]

[0063] As shown in Table 1, the introduction of interference current weakens the amplitude of the output voltage, resulting in measurement error, with the maximum error being around 10%.

[0064] When an interfering current exists outside the Rogowski coil, its change generates an alternating magnetic field. This alternating magnetic field induces an electromotive force in the Rogowski coil, which is the fundamental cause of measurement errors. The magnitude of the measurement error is related to the value of the interfering current and the distance between the interfering current and the measured current. As shown in Table 1, the interfering signal is very large, comparable to the measured signal, and the distance between the interfering signal and the Rogowski coil is short, thus causing a significant measurement error. In practical applications, care should be taken to keep the interfering current away from the Rogowski coil, and the measurement error can be reduced when conditions permit. Electricity meters are often exposed to external power frequency magnetic fields due to improper installation and wiring at work sites, leading to inaccurate metering. To ensure reliable operation of electricity meters, the State Grid standard Q / GDW 10364-2020 requires electricity meters to undergo an external power frequency magnetic field test. This test involves applying an external magnetic induction of 0.5 mT generated by a power frequency current at nominal voltage and current of 10 Itr and Imax, with a power factor of 1, to three vertical planes of the electricity meter. The meter is positioned at the center of the induction coil. The direction and phase of the external magnetic induction on the meter are changed, and the maximum deviation of the meter error is determined as the condition under which the meter is exposed to the most unfavorable direction and phase of the external power frequency magnetic field. The limit for the meter error deviation is ±1.3%. Therefore, it is essential to mitigate the impact of power frequency magnetic fields on metering, especially for metering products using Rogowski coils as sampling elements.

[0065] In a preferred embodiment of the present invention, the first position represents the position of the product to be output as a meter; the first magnetic field strength represents the magnetic field strength at the product to be output as a meter; the second position represents the position of the current element to be measured, wherein a plurality of current elements to be measured can form a current to be measured; the third position represents the position of the current sampling element; the coil radius represents the radius of the coil in the current sampling element; and the sampling data represents the current signal collected by the current sampling element. First, the first position, first magnetic field strength, magnetic field direction, and vacuum permeability of the product to be output as a meter are obtained; the second position, length, and direction of the current element to be measured; the third position, coil radius, and sampling data of the current sampling element; then, because the directions of the product to be output as a meter and the current element to be measured are not necessarily in the same plane, and the installation directions of the current sampling elements are different, the magnitudes of the induced currents generated are also different. Therefore, it is necessary to calculate the angle between the product to be output as a meter and the current element to be measured based on the first position, the second position, the magnetic field direction, and the current element direction. Next, based on the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum permeability, the coil radius, and the included angle, the induced current generated by the current sampling element is calculated. Finally, based on the sampling data and the induced current, compensation calculations are performed to obtain the metering current of the metering product to be output. This method compensates for and cancels the specific induced current generated by the external current sampling element, thereby improving the anti-interference capability of the external metering product under the influence of an external magnetic field.

[0066] Preferably, the direction of the magnetic field is perpendicular to the direction of the current element;

[0067] Based on the first position, the second position, the direction of the magnetic field, and the direction of the current element, the angle between the output metering product and the measured current element is calculated, including:

[0068] A spatial rectangular coordinate system is constructed with the direction of the magnetic field as the horizontal axis and the direction of the current element as the vertical axis.

[0069] Based on the first position and the second position, the straight-line distance between the metering product to be output and the current element to be measured is calculated;

[0070] Based on the first position, the straight-line distance, and the spatial rectangular coordinate system, the angle between the metering product to be output and the current element to be measured is calculated.

[0071] In a preferred embodiment of the present invention, such as Figure 8 As shown, the magnetic field strength at the current position of the electricity meter (the first position of the metering product) is B, and its direction is along the positive X-axis, generated by the current I of the current element. In the figure, α, α1, and α2 are the angles between the metering product to be output and the current element to be measured.

[0072] Specifically, the induced current generated by the current sampling element is calculated based on the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum permeability, the coil radius, and the included angle, including:

[0073] The current of the current element is calculated based on the first magnetic field strength, the first position, the second position, the length of the current element, the vacuum permeability, and the included angle.

[0074] The second magnetic field strength at the current sampling element is calculated based on the current of the current element, the second position, the third position, the length of the current element, and the vacuum permeability.

[0075] The induced current of the current sampling element is calculated based on the second magnetic field strength, the second position, the third position, the coil radius, and the vacuum permeability.

[0076] Specifically, according to the Biot-Savart law, the magnitude of the magnetic field produced by a current element at a point is directly proportional to the magnitude of the current element I, inversely proportional to the square of the magnitude of the position vector from the current element to that point, and directly proportional to the sine of the angle between the current element and the position vector. The calculation formula is as follows:

[0077]

[0078] When the magnetic field measurement point, i.e., the first position, is located on the perpendicular bisector of the current element, the formula simplifies to: Where μ0 is the free permeability, yes The unit vector, R is The modulus represents the distance from the current element to the measurement point. Since the Rogowski coil is composed of small turns of wire, according to Ampere's circuital law, the loop integral of the magnetic field strength is equal to the current through the loop multiplied by the permeability of vacuum. Considering a closed loop of unknown shape with N turns of wire wound on it, the following equation can be derived:

[0079] ∮B2·dl=μ0·I;

[0080] Where ∮B²·dl represents the loop integral of the magnetic field strength over one revolution in the closed loop, and I represents the current through the loop. Considering the number of turns N of the coil, the loop integral in the closed loop can be decomposed into the sum of the loop integrals of each turn of the coil. Since the lines of each turn are parallel, the current through each turn of the coil is equal. Therefore, the following equation is obtained:

[0081] ∮B2·dl=N·∮b·dl=μ0·N·I;

[0082] Where ∮b·dl represents the loop integral through each turn of the coil. Since each turn of the coil is a closed loop, the loop integral can be expressed as the integral of the magnetic field strength within the loop of the coil. Assuming the magnetic field strength is uniform within the coil, the loop integral per turn can be simplified to the product of the magnetic field strength and the area of ​​the loop within the coil. Therefore, the following equation can be obtained:

[0083] ∮b·dl=B2·A;

[0084] Where B2 represents the magnetic field strength, and A represents the area of ​​the inner loop of the coil. Ultimately, the relationship between the magnetic field strength and the number of coil turns can be obtained:

[0085]

[0086] Because the small turns of the Rogowski coil are spirally wound tightly around the entire coil frame, forming an equivalent large turn along the winding direction, N=1, and the derivation is as follows:

[0087]

[0088] r is the radius of the Rogowski coil.

[0089] In a preferred embodiment of the present invention, the current of the current element is calculated based on the first magnetic field strength, the first position, the second position, the length of the current element, the vacuum permeability, and the included angle; then, the second magnetic field strength at the current sampling element is calculated based on the current of the current element, the second position, the third position, the length of the current element, and the vacuum permeability; finally, the induced current of the current sampling element is calculated based on the second magnetic field strength, the second position, the third position, the coil radius, and the vacuum permeability.

[0090] In another preferred embodiment of the present invention, the first magnetic field strength is 0.5 mT, the current element length is 1.5 m, the distance between the first and second positions is 10 cm, the current position of the measuring product is perpendicular to the current element, i.e., B = 0.5 × 10⁻³ T, R = 10 cm = 0.1 m, the current element length dl = 1.5 m, and the perpendicular angle is 90°. Substituting into the Biot-Savart law formula:

[0091]

[0092]

[0093] Simplified equation:

[0094] 0.5 × 10⁻³ = 10⁻⁷ × 150I;

[0095] The calculation yields: I ≈ 33.33A;

[0096] The current element is considered the interference source, and its second position is taken as the center of the interference source. Assuming the Rogowski coil (current sampling element) is located at the center of the energy meter (measuring product) and the interference source (current element), i.e., R = 5cm, substituting this into the Biot-Savart law, we can calculate that the second magnetic field strength is approximately 2mT. Therefore, the interference generated by the interference source in the Rogowski coil is 2mT. Then, substituting the second magnetic field strength into the formula... Perform the calculation:

[0097]

[0098] After simplifying the formula, the induced current is calculated to be I ≈ 3.125A. Therefore, when the magnetic field at the center of the electricity meter is 0.5mT, and the Rogowski coil is located at the center of the electricity meter and the center of the interference source, the induced current generated is 3.125A.

[0099] Specifically, the product to be output and the current sampling element are externally connected, such as... Figure 9 As shown. The product to be output includes: a metering module, a magnetic detection module, and a microcontroller module; the metering module is connected to the current sampling element and the microcontroller module respectively; the magnetic detection module is connected to the microcontroller module;

[0100] The metering module is used to receive the sampling data from the current sampling element and the metering current from the microcontroller module, and to transmit the sampling data to the microcontroller module.

[0101] The magnetic detection module is used to detect the magnetic field to obtain the first magnetic field strength and magnetic field direction, and transmit the first magnetic field strength and magnetic field direction to the microcontroller module.

[0102] The microcontroller module is used to receive sampling data, the first magnetic field strength and the magnetic field direction, calculate the induced current and the metering current, and return the metering current to the metering module.

[0103] In a preferred embodiment of the present invention, such as Figure 9As shown, the MCU is a microcontroller module, the metering function module is the metering module, and the magnetic detection function module is the magnetic detection module. Due to the influence of the magnetic field from the interference source, the metering function of the metering product may deviate. In this case, the magnetic detection module detects the magnetic field to obtain a first magnetic field strength and direction, and transmits these parameters to the microcontroller module. The microcontroller module receives the sampling data from the sampling element, the first magnetic field strength, and the magnetic field direction sent by the magnetic detection module, calculates the induced current and the metering current, and returns the metering current to the metering module. The metering module receives the sampling data from the current sampling element and the metering current from the microcontroller module, and then transmits the sampling data to the microcontroller module.

[0104] In another preferred embodiment of the present invention, the electricity meter, as a metering product, can output the magnitude of the detected current or voltage value. For example... Figure 10 As shown, within the energy meter, based on the magnetic field strength, current sampling element, and direction of the interference source current element, the magnitude of the induced current and the detected current are obtained. Then, compensation calculations are performed to obtain the actual measured current data. The energy meter, through its magnetic detection module and microcontroller module, calculates the interfering magnetic field at the Rogowski coil's installation location. Due to installation reasons, the Rogowski coil is wrapped around the current line, affecting the accuracy of the Rogowski coil current measurement. The magnetic field is perpendicular to the XZ plane of the magnetic field generated by the actual power line; therefore, the magnetic field detected by the energy meter is the vector sum of two mutually perpendicular magnetic fields. The installation position of the Rogowski coil (third position) has been recorded in the energy meter. The energy meter MCU uses a corresponding algorithm to compensate for and cancel the specific induced current generated by the external current sampling element, calculating the magnitude of the magnetic field induced current (interference current). When the magnetic field detected by the magnetic induction chip in the energy meter is the same as the magnetic field generated by the power line, it indicates that there is no interference.

[0105] In a preferred embodiment of the present invention, the experimental verification of the interference current induced by the magnetic field is shown in Table 2:

[0106] Table 2

[0107]

[0108]

[0109] According to the experimental verification data, when a 0.5mT power frequency magnetic field affects the Rogowski coil, the average induced current is approximately 863.3mA. Substituting these values ​​into the calculation formula... The verification result is correct.

[0110] In another preferred embodiment of the invention, it is assumed that the current power frequency magnetic field detected by the center of the electricity meter is 0.5 mT and the Rogowski coil measures a current of 100 A in the actual circuit. According to previous calculations, there is an induced current of 3.125 A in the Rogowski coil. Since the actual current in the circuit is 100 A, the magnetic field in the vertical direction is calculated according to the Biot-Savart law. Figure 8 The magnetic field generated by the power line (interference source) in the X-axis direction is 6mT. The current information collected by the electricity meter is approximately 103.125A. The magnetic detection module of the electricity meter detects... Figure 8 The magnetic field magnitudes along the X and Z axes of the diagram showing the magnetic field generated by the power line (interference source) are 6 mT and 0.5 mT, respectively. Based on calculations, the electricity meter program compensates for the actual current by 103.125 A - 100 A, resulting in 3.125 A. This improves measurement accuracy, reduces the impact of the magnetic field on the electricity meter, and enhances its metering precision. When the Rogowski coil is affected by a power frequency magnetic field, it induces an interference current I'. The actual current collected by the electricity meter through the Rogowski coil is I + I', where I is the actual current (with direction) in the power line, and I' is the interference current induced by the magnetic field. By analyzing the magnetic field detected by the electricity meter's magnetic field detection module and processing the meter's program, the current I' generated by the magnetic field can be calculated. After removing the induced interference current, the magnitude of I in the actual power line is obtained.

[0111] By implementing this embodiment, the first position, first magnetic field strength, magnetic field direction, vacuum permeability of the metering product to be output, the second position, length, direction of the current element to be measured, the third position of the current sampling element, the coil radius, and sampling data can be obtained. Based on the first position, second position, magnetic field direction, and current element direction, the angle between the metering product to be output and the current element to be measured is calculated. Based on the first magnetic field strength, first position, second position, third position, length of the current element, vacuum permeability, coil radius, and the angle, the induced current generated by the current sampling element is calculated. Based on the sampling data and the induced current, compensation calculations are performed to obtain the metering current of the metering product to be output. By using parameters such as the angle between the metering product to be output and the current element to be measured, the magnetic field strength, and positional relationship, the induced current generated by the current sampling element can be calculated more accurately. Further compensation calculations can eliminate or reduce errors caused by the induced current generated by factors such as magnetic field interference and current fluctuations in the current sampling element, thereby improving the anti-interference capability of the energy metering product and improving the accuracy of the metering current.

[0112] See Figure 2 This is a schematic diagram of the structure of an anti-interference system for an electricity metering product according to an embodiment of the present invention, comprising:

[0113] The data acquisition module is used to acquire the first position, first magnetic field strength, magnetic field direction, vacuum permeability, second position, current element length, current element direction, third position, coil radius, and sampling data of the metering product to be output;

[0114] The metering angle calculation module is used to calculate the angle between the metering product to be output and the current element to be measured based on the first position, the second position, the direction of the magnetic field and the direction of the current element.

[0115] The induced current calculation module is used to calculate the induced current generated by the current sampling element based on the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum permeability, the coil radius, and the included angle.

[0116] The metering data output module is used to perform compensation calculations based on the sampled data and the induced current to obtain the metering current of the metering product to be output.

[0117] Specifically, the direction of the magnetic field is perpendicular to the direction of the current element; the metering angle calculation module is used to calculate the angle between the metering product to be output and the current element to be measured based on the first position, the second position, the direction of the magnetic field, and the direction of the current element, including:

[0118] The spatial coordinate system construction submodule is used to construct a spatial rectangular coordinate system with the direction of the magnetic field as the horizontal axis and the direction of the current element as the vertical axis.

[0119] The distance calculation submodule is used to calculate the straight-line distance between the metering product to be output and the current element to be measured based on the first position and the second position.

[0120] The included angle calculation submodule is used to calculate the included angle between the metering product to be output and the current element to be measured based on the first position, the straight-line distance, and the spatial rectangular coordinate system.

[0121] Preferably, the induced current calculation module is used to calculate the induced current generated by the current sampling element based on the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum permeability, the coil radius, and the included angle, including:

[0122] The current element current calculation submodule is used to calculate the current element current based on the first magnetic field strength, the first position, the second position, the current element length, the vacuum permeability, and the included angle.

[0123] The second magnetic field strength calculation submodule is used to calculate the second magnetic field strength at the current sampling element based on the current of the current element, the second position, the third position, the length of the current element, and the vacuum permeability.

[0124] The sampling element calculation submodule is used to calculate the induced current of the current sampling element based on the second magnetic field strength, the second position, the third position, the coil radius, and the vacuum permeability.

[0125] This invention provides an anti-interference system for electricity metering products. The system comprises: a data acquisition module that acquires the first position, first magnetic field strength, magnetic field direction, vacuum permeability, second position, current element length, current element direction, third position of the current sampling element, coil radius, and sampling data of the metering product to be output; a metering angle calculation module that calculates the angle between the metering product and the current element to be measured based on the first position, second position, magnetic field direction, and current element direction; an induced current calculation module that calculates the induced current generated by the current sampling element based on the first magnetic field strength, first position, second position, third position, current element length, vacuum permeability, coil radius, and the angle; and finally, a metering data output module that performs compensation calculations based on the sampling data and the induced current to obtain the metering current of the metering product to be output. By using parameters such as the angle between the metering product to be output and the current element to be measured, the induced current generated by the current sampling element can be calculated more accurately. Further compensation calculations can eliminate or reduce the error caused by the induced current generated by the current sampling element due to factors such as magnetic field interference and current fluctuations, thereby improving the anti-interference ability of the power metering product and improving the accuracy of the metering current.

[0126] It should be noted that the system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the system embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0127] Those skilled in the art will understand that, for convenience and brevity, the specific working process of the system described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0128] Another embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements an anti-interference method for an electricity metering product as described in the above embodiments. The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0129] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the terminal device, connecting all parts of the terminal device via various interfaces and lines.

[0130] The memory can be used to store the computer program. The processor implements various functions of the terminal device by running or executing the computer program stored in the memory and calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function, etc.; the data storage area may store data created based on the use of the mobile phone, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, RAM, plug-in hard disk, smart memory card (SMC), secure digital card (SD), flash memory card, at least one disk storage device, flash memory device or other volatile solid-state storage device.

[0131] Another embodiment of the present invention provides a computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to perform an anti-interference method for an electricity metering product as described in the above embodiment.

[0132] The storage medium is a computer-readable storage medium, and the computer program is stored in the computer-readable storage medium. When the computer program is executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0133] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preventing interference in an electricity metering product, characterized in that, A microcontroller module suitable for an anti-interference system of electricity metering products; the anti-interference method for the electricity metering product includes: Acquire the first position, first magnetic field strength, magnetic field direction and vacuum permeability of the product to be output, the second position, current element length and current element direction of the current element to be measured, and the third position, coil radius and sampling data of the current sampling element; Based on the first position, the second position, the direction of the magnetic field, and the direction of the current element, the angle between the metering product to be output and the current element to be measured is calculated. The induced current generated by the current sampling element is calculated based on the first magnetic field strength, the first position, the second position, the third position, the length of the current element, the vacuum permeability, the coil radius, and the included angle. Based on the sampled data and the induced current, a compensation calculation is performed to obtain the metering current of the product to be output. Among them, the current element is used as the interference source, and the second position of the current element is used as the center position of the interference source.

2. The anti-interference method for an electricity metering product as described in claim 1, characterized in that, The direction of the magnetic field is perpendicular to the direction of the current element; Based on the first position, the second position, the direction of the magnetic field, and the direction of the current element, the angle between the output metering product and the measured current element is calculated, including: A spatial rectangular coordinate system is constructed with the direction of the magnetic field as the horizontal axis and the direction of the current element as the vertical axis. Based on the first position and the second position, the straight-line distance between the metering product to be output and the current element to be measured is calculated; Based on the first position, the straight-line distance, and the spatial rectangular coordinate system, the angle between the metering product to be output and the current element to be measured is calculated.

3. The anti-interference method for an electricity metering product as described in claim 1, characterized in that, The induced current generated by the current sampling element is calculated based on the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum permeability, the coil radius, and the included angle, including: The current of the current element is calculated based on the first magnetic field strength, the first position, the second position, the length of the current element, the vacuum permeability, and the included angle. The second magnetic field strength at the current sampling element is calculated based on the current of the current element, the second position, the third position, the length of the current element, and the vacuum permeability. The induced current of the current sampling element is calculated based on the second magnetic field strength, the second position, the third position, the coil radius, and the vacuum permeability.

4. The anti-interference method for an electricity metering product as described in claim 1, characterized in that, The metering product to be output is externally connected to the current sampling element.

5. The anti-interference method for an electricity metering product as described in claim 1, characterized in that, The product to be output further includes: a metering module and a magnetic detection module; the metering module is connected to the current sampling element and the microcontroller module respectively; the magnetic detection module is connected to the microcontroller module. The metering module is used to receive the sampling data from the current sampling element and the metering current from the microcontroller module, and to transmit the sampling data to the microcontroller module. The magnetic detection module is used to detect the magnetic field to obtain the first magnetic field strength and magnetic field direction, and transmit the first magnetic field strength and magnetic field direction to the microcontroller module. The microcontroller module is used to receive sampling data, the first magnetic field strength and the magnetic field direction, calculate the induced current and the metering current, and return the metering current to the metering module.

6. An anti-interference system for an electricity metering product, characterized in that, include: The data acquisition module is used to acquire the first position, first magnetic field strength, magnetic field direction and vacuum permeability of the metering product to be output, the second position, current element length and current element direction of the current element to be measured, the third position, coil radius and sampling data of the current sampling element; The metering angle calculation module is used to calculate the angle between the metering product to be output and the current element to be measured based on the first position, the second position, the direction of the magnetic field and the direction of the current element. The induced current calculation module is used to calculate the induced current generated by the current sampling element based on the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum permeability, the coil radius, and the included angle. The metering data output module is used to perform compensation calculations based on the sampled data and the induced current to obtain the metering current of the metering product to be output. Among them, the current element is used as the interference source, and the second position of the current element is used as the center position of the interference source.

7. The anti-interference system for an electricity metering product as described in claim 6, characterized in that, The direction of the magnetic field is perpendicular to the direction of the current element; The metering angle calculation module is used to calculate the angle between the metering product to be output and the current element to be measured based on the first position, the second position, the direction of the magnetic field, and the direction of the current element, including: The spatial coordinate system construction submodule is used to construct a spatial rectangular coordinate system with the direction of the magnetic field as the horizontal axis and the direction of the current element as the vertical axis. The distance calculation submodule is used to calculate the straight-line distance between the metering product to be output and the current element to be measured based on the first position and the second position. The included angle calculation submodule is used to calculate the included angle between the metering product to be output and the current element to be measured based on the first position, the straight-line distance, and the spatial rectangular coordinate system.

8. The anti-interference system for an electricity metering product as described in claim 6, characterized in that, The induced current calculation module is used to calculate the induced current generated by the current sampling element based on the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum permeability, the coil radius, and the included angle, including: The current element current calculation submodule is used to calculate the current element current based on the first magnetic field strength, the first position, the second position, the current element length, the vacuum permeability, and the included angle. The second magnetic field strength calculation submodule is used to calculate the second magnetic field strength at the current sampling element based on the current of the current element, the second position, the third position, the length of the current element, and the vacuum permeability. The sampling element calculation submodule is used to calculate the induced current of the current sampling element based on the second magnetic field strength, the second position, the third position, the coil radius, and the vacuum permeability.

9. A terminal device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements an anti-interference method for an electricity metering product as described in any one of claims 1 to 5.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to perform an anti-interference method for an electricity metering product as described in any one of claims 1 to 5.

Images