Electric energy metering product anti-interference method and system, terminal equipment and storage medium

Abstract

The invention discloses an electric energy metering product anti-interference method and system, terminal equipment and a storage medium. The method comprises the following steps: acquiring a first position, a first magnetic field intensity, a magnetic field direction and a vacuum magnetic conductivity of a to-be-output metering product, a second position, a current element length and a current element direction of a to-be-measured current element, a third position of a current sampling element, a coil radius and sampling data; according to the first position, the second position, the magnetic field direction and the current element direction, calculating an included angle between the to-be-output metering product and the to-be-measured current element; calculating according to the first magnetic field intensity, the first position, the second position, the third position, the current element length, the vacuum magnetic conductivity, the coil radius and the included angle to obtain an induced current generated by the current sampling element; and performing compensation calculation according to the sampling data and the induction current to obtain the metering current of the to-be-output metering product. According to the invention, the anti-interference capability of a metering product is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of current sampling, and in particular to an anti-interference method, system, terminal equipment and storage medium for electric energy metering products. Background Art

[0002] The current sampling components of the electric energy metering products currently on the market can be divided into two types in terms of installation method: built-in and external. The external current sampling components can be Rogowski coils, etc. With the gradual maturity of Rogowski coil current transformer technology, its use in electric energy metering in the power industry is becoming more and more widespread. Especially in situations with large dynamic current changes, many electrical equipment have adopted Rogowski coils to replace CTs for large dynamic range current sampling. Rogowski coils are hollow coils without magnetic cores and are easily affected by power frequency magnetic fields. As an external current sampling component, Rogowski coils are connected in series to the line to detect current, which is easily affected by the power frequency and generates additional induced current, resulting in large measurement errors in the metering products. Summary of the invention

[0003] The embodiments of the present invention provide an anti-interference method, system, terminal device and storage medium for electric energy metering products, which can effectively solve the problem that the external current sampling element in the prior art is connected in series with the line to detect the current, which is easily affected by the power frequency and generates additional induced current, resulting in large measurement errors of the metering product.

[0004] An embodiment of the present invention provides an anti-interference method for an electric energy metering product, which is applicable to a microcontroller module of an anti-interference system of an electric energy metering product; the anti-interference method for an electric energy metering product comprises:

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

[0006] Calculate the angle between the metering product to be output and the current element to be measured according to the first position, the second position, the direction of the magnetic field and the direction of the current element;

[0007] Calculate according to the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum magnetic permeability, the coil radius and the angle to obtain the induced current generated by the current sampling element;

[0008] Compensation calculation is performed according to the sampling data and the induced current to obtain a metering current of the metering product to be output.

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

[0010] Calculating the angle between the metering product to be output and the current element to be measured according to the first position, the second position, the magnetic field direction, and the current element direction includes:

[0011] Constructing a spatial rectangular coordinate system by taking the direction of the magnetic field as the horizontal axis of the spatial rectangular coordinate system and taking the direction of the current element as the vertical axis of the spatial rectangular coordinate system;

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

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

[0014] Further, the induced current generated by the current sampling element is obtained by calculation according to the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum magnetic permeability, the coil radius and the angle, including:

[0015] Calculating according to the first magnetic field strength, the first position, the second position, the current element length, the vacuum magnetic permeability, and the angle to obtain the current element current;

[0016] Calculating a second magnetic field intensity at a current sampling element according to the current element current, the second position, the third position, the current element length, and the vacuum magnetic permeability;

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

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

[0019] Furthermore, the metering 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 of the current sampling element and the metering current of the micro-control module, and transmit the sampling data to the micro-control module;

[0021] The magnetic detection module is used to detect the magnetic field to obtain a first magnetic field strength and a magnetic field direction, and transmit the first magnetic field strength and the magnetic field direction to the micro control module;

[0022] The microcontrol module is used to receive the 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 of the above solution, another embodiment of the present invention provides an anti-interference system for electric energy metering products, including:

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

[0025] A metering angle calculation module, used to calculate the angle between the metering product to be output and the current element to be measured according to the first position, the second position, the magnetic field direction and the current element direction;

[0026] an induced current calculation module, configured to calculate, according to the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum magnetic permeability, the coil radius and the angle, to obtain the induced current generated by the current sampling element;

[0027] The metering data output module is used to perform compensation calculation according to the sampling data and the induced current to obtain the metering current of the metering product to be output.

[0028] Further, 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 according to the first position, the second position, the magnetic field direction and the current element direction, including:

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

[0031] A distance calculation submodule, used for calculating the straight-line distance between the metering product to be output and the current element to be measured according to the first position and the second position;

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

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

[0034] a current element current calculation submodule, configured to calculate according to the first magnetic field strength, the first position, the second position, the current element length, the vacuum permeability, and the angle to obtain the current element current;

[0035] A second magnetic field strength calculation submodule, configured to calculate a second magnetic field strength at a current sampling element according to the current element current, the second position, the third position, the current element length, and the vacuum permeability;

[0036] The sampling element calculation submodule is used to calculate the induced current of the current sampling element according to 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, and when the processor executes the computer program, an anti-interference method for an electric energy metering product as described in the above embodiment is implemented.

[0038] Another embodiment of the present invention provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the anti-interference method for electric energy metering products described in the above embodiment.

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

[0040] The present invention provides an anti-interference method, system, terminal device and storage medium for electric energy metering products. The method is applicable to a microcontroller module of an anti-interference system for electric energy metering products, and can obtain a first position, a first magnetic field strength, a magnetic field direction, a vacuum magnetic permeability, a second position, a current element length, a current element direction, a third position, a coil radius and sampling data of a metering product to be output; according to the first position, the second position, the magnetic field direction and the current element direction, the angle between the metering product to be output and the current element to be measured is calculated; according to the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum magnetic permeability, the coil radius and the angle, the induced current generated by the current sampling element is calculated; according to the sampling data and the induced current, compensation calculation is performed to obtain the metering current of the metering product to be output. Through parameters such as the angle between the output metering product and the current element to be measured, the magnetic field strength, and the position relationship, the induced current generated by the current sampling element can be calculated more accurately. Further compensation calculation 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 electric energy metering product and the accuracy of the measured current. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a flow chart of an anti-interference method for an electric energy metering product provided by an embodiment of the present invention;

[0042] Figure 2 It is a structural schematic diagram of an anti-interference system for an electric energy metering product provided by an embodiment of the present invention;

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

[0044] Figure 4 This is a schematic diagram of an external metering product provided by an embodiment of the present invention being interfered by a magnetic field;

[0045] Figure 5 It is a schematic diagram of a single-phase electric energy meter framework provided by an embodiment of the present invention;

[0046] Figure 6 is a schematic diagram of a Rogowski coil provided by an embodiment of the present invention;

[0047] Figure 7 Schematic diagram of equivalent large turns of a Rogowski coil provided by an embodiment of the present invention;

[0048] Figure 8 is a schematic diagram of a magnetic field generated by an interference source provided by an embodiment of the present invention;

[0049] Fig. 9 is a logical schematic diagram of a compensation solution provided by an embodiment of the present invention;

[0050] Fig.10 It is a schematic diagram of the processing flow in an electric energy meter provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] See also Figure 1 , is a flow chart of an anti-interference method for an electric energy metering product provided by an embodiment of the present invention, the anti-interference method for an electric energy metering product is applicable to a microcontroller module of an anti-interference system of an electric energy metering product; the anti-interference method for an electric energy metering product comprises:

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

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

[0055] S3, calculating according to the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum magnetic permeability, the coil radius and the angle to obtain the induced current generated by the current sampling element;

[0056] S4. Perform compensation calculation according to the sampling data and the induced current to obtain a metering current of the metering product to be output.

[0057] Specifically, current sampling components can be divided into two types according to the installation method: built-in and external. External current sampling components can be open current transformers and Rogowski coils. Under external magnetic field interference, electric energy metering products with built-in current sampling components usually use current line twisting to offset magnetic field interference and improve the metering product's resistance to external magnetic field interference, because the current sampling components are built-in and close to the metering circuit in the metering product. Figure 3However, the external current sampling components are different because the current sampling components of external electric energy metering products are far away from the metering circuit of the metering product, such as Figure 4 As shown in the figure, the magnetic field faced by the beginning (measurement product side) and the end (coil side) of the current sampling element will be attenuated (with the measurement product as the center point). In addition to the loss on the line (because the line distance can be as long as 0.5 meters), the traditional built-in current compensation method is not suitable for external type.

[0058] Specifically, taking a single-phase electric energy meter as an example, the working principle of the Rogowski coil as an external current sampling element is explained. Figure 5 As shown in the figure, a single Rogowski coil electric energy meter includes an MCU (microcontroller module), a single-phase metering chip, a voltage sampling circuit, a Rogowski coil and a current sampling circuit. The Rogowski coil is connected to the circuit as a current transformer, and is connected to the AD sampling terminal of the metering chip through the current sampling circuit. The metering chip is connected to the MCU through the SPI bus (serial peripheral interface). Compared with traditional current transformers or manganese copper sampling, the use of Rogowski coils as current transformers has the advantages of wide dynamic range, flexible installation, and non-stop installation, so it has a wide application prospect. The current sensor is a device for detecting current, which can sense the information of the measured current and convert it into an electrical signal that meets the standard requirements according to certain rules. There are two main types of current sensors. One is an iron core coil transformer, which can be made into different sizes according to the rated current. The disadvantage is that the iron core has magnetic saturation and nonlinearity, so the current measurement range is narrow; the other is a Rogowski coil, which has the characteristics of wide dynamic range, excellent linear characteristics, small size and low cost. Whether it is an iron core coil mutual inductor or a Rogowski coil, this type of current sampling external sampling element is easily affected by the power frequency, thereby generating additional induced current, resulting in large measurement errors. In particular, the Rogowski coil is an air-core coil without a magnetic core, which is more susceptible to the power frequency magnetic field.

[0059] like Figure 6 As shown in the figure, the small turns of the Rogowski coil are tightly wound on the entire coil frame, forming an equivalent large turn along the winding direction (such as Figure 7 As shown in Figure 1.1, the magnetic field B is perpendicular to the plane where the large wire turn is located. When the magnetic field changes with time, the magnetic flux passing through the large wire turn changes accordingly, thereby generating an induced electromotive force e in the Rogowski coil. Although the large wire turn has only one circle, the area of ​​the large wire turn is usually much larger than the cross-sectional area of ​​the small wire turn. Even if the vertical interference magnetic field strength is similar to the magnetic induction strength generated by the conductor to be measured, it will cause significant errors in the measurement results. Through calculation, it can be seen that the influence of the magnetic field in the parallel direction on the Rogowski coil is 0, which can be ignored and will not be analyzed in detail here.

[0060] The output voltage data of the Rogowski coil before and after being disturbed by the power frequency current is shown in Table 1:

[0061] Table 1

[0062]

[0063] It can be seen from Table 1 that the introduction of interference current weakens the amplitude of the output voltage, resulting in measurement errors, with the maximum error being around 10%.

[0064] When there is an interference current outside the Rogowski coil, an alternating magnetic field is generated due to the change of the interference current, and the alternating magnetic field generates an induced potential in the Rogowski coil, which is the fundamental reason for the measurement error. The size of the measurement error is related to the value of the interference current and the distance between the interference current and the measured current. As shown in the test in Table 1, the interference signal is very large, comparable to the measured signal, and the distance between the interference signal and the Rogowski coil is short, which causes a large measurement error. In actual use, care should be taken to keep the interference current away from the Rogowski coil. If conditions permit, reducing the interference current can reduce the measurement error. Electricity meters are often placed in a power frequency magnetic field in space due to unreasonable installation and wiring at the work site, causing mismeasurement. In order to ensure the reliable operation of the energy meter, the State Grid Standard Q / GDW 10364-2020 requires the energy meter to pass the external power frequency magnetic field test, that is, "under the conditions of nominal voltage, current applied 10I tr, Imax, and power factor 1, an external magnetic induction of 0.5mT is generated by the power frequency current and applied to three vertical planes of the energy meter. The tested energy meter is at the center of the induction coil. The direction and phase of the external magnetic induction on the energy meter are changed. The maximum offset of the energy meter error is determined as the condition where the energy meter is in the most unfavorable direction and phase of the external power frequency magnetic field. The error offset limit of the energy meter is ±1.3%". Therefore, it is necessary to try to reduce the impact of the power frequency magnetic field on measurement, especially for metering products that use Rogowski coils as sampling elements.

[0065] In a preferred embodiment of the present invention, the first position indicates the position of the metering product to be output; the first magnetic field strength indicates the magnetic field strength at the metering product to be output; the second position indicates the position of the current element to be measured, wherein a plurality of current elements to be measured can form the current to be measured; the third position indicates the position of the current sampling element; the coil radius indicates the radius of the coil in the current sampling element; and the sampling data indicates the current signal collected by the current sampling element. First, the first position of the metering product to be output, the first magnetic field strength, the magnetic field direction, the vacuum magnetic permeability, the second position of the current element to be measured, the current element length, the current element direction, the third position of the current sampling element, the coil radius and the sampling data are obtained; then, because the directions of the metering product to be output and the current element to be measured are not necessarily in the same plane, and the directions of the current sampling element installation are different, the magnitude of the induced current generated is also different, so it is necessary 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 magnetic field direction and the current element direction. Then, 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 magnetic permeability, the coil radius and the angle; finally, compensation calculation is performed based on the sampling data and the induced current to obtain the metering current of the metering product to be output. The specific induced current generated by the external current sampling element is compensated and offset, thereby improving the anti-interference ability of the external metering product under the influence of the external magnetic field.

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

[0067] Calculating the angle between the metering product to be output and the current element to be measured according to the first position, the second position, the magnetic field direction, and the current element direction includes:

[0068] Constructing a spatial rectangular coordinate system by taking the direction of the magnetic field as the horizontal axis of the spatial rectangular coordinate system and taking the direction of the current element as the vertical axis of the spatial rectangular coordinate system;

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

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

[0071] In a preferred embodiment of the present invention, Figure 8 As shown, the magnetic field strength at the current position of the electric energy meter (the first position of the metering product) is B, and the direction is along the positive direction of the X-axis, generated by the current element current I. In the figure, ɑ, ɑ1 and ɑ2 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 obtained by calculating according to the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum magnetic permeability, the coil radius and the angle, including:

[0073] Calculating according to the first magnetic field strength, the first position, the second position, the current element length, the vacuum magnetic permeability, and the angle to obtain the current element current;

[0074] Calculating a second magnetic field intensity at a current sampling element according to the current element current, the second position, the third position, the current element length, and the vacuum magnetic permeability;

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

[0076] Specifically, according to the Biot-Savart law, the magnitude of the magnetic field generated by the current element at a certain point is 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 the point, and 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 is simplified to: Where μ0 is the magnetic permeability of vacuum, yes The unit vector of The modulus of the current element represents the distance from the measuring point. Since the Rogowski coil is composed of small turns of wire, according to Ampere's loop law, the loop integral of the magnetic field strength is equal to the current passing through the loop multiplied by the magnetic permeability in the vacuum. Consider a closed loop of unknown shape with N turns of coil wound around it, and the following equation can be obtained:

[0079] ∮B2·dl=μ0·I;

[0080] Among them, ∮B2·dl represents the loop integral of the magnetic field intensity around one circle on the closed loop, and I represents the current passing through the loop. Considering the number of turns N of the coil, the loop integral on 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 passing through each turn of the coil is equal. Therefore, the following equation is obtained:

[0081] ∮B2·dl=N·∮b·dl=μ0·N·I;

[0082] Among them, ∮b·dl represents the loop integral of each turn of the coil. Since each turn of the coil is closed, the loop integral can be expressed as the integral of the magnetic field intensity in the loop inside the coil. Assume that the magnetic field intensity is uniform inside the coil. In this case, the loop integral of each turn of the coil can be simplified to the product of the magnetic field intensity and the area of ​​the loop inside the coil. Therefore, the following equation can be obtained:

[0083] ∮b·dl=B2·A;

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

[0085]

[0086] Since the small turns of the Rogowski coil are tightly wound on the entire coil frame, an equivalent large turn along the winding direction is formed, so N = 1, and it is derived that:

[0087]

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

[0089] In a preferred embodiment of the present invention, the current element current is calculated based on the first magnetic field strength, the first position, the second position, the current element length, the vacuum permeability and the angle; then the second magnetic field strength at the current sampling element is calculated based on the current element current, the second position, the third position, the current element length 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 is 10 cm according to the first position and the second position, and the current position of the metering product is perpendicular to the current element, that is, B = 0.5 × 10-3 T, R = 10 cm = 0.1 m, the current element length dl = 1.5 m, the vertical angle is 90 °, and the Biot-Savart law formula is substituted:

[0091]

[0092]

[0093] Simplified equation:

[0094] 0.5×10-3=10-7×150I;

[0095] Calculated: I≈33.33A;

[0096] 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. Assuming that the Rogowski coil (current sampling element) is located at the center of the energy meter (metering product) and the interference source (current element), that is, R = 5cm, re-substituting the Biot-Savart law to calculate, it can be concluded that the second magnetic field strength is about 2mT, so the interference generated by the interference source in the Rogowski coil is 2mT. Then substitute the second magnetic field strength into the formula Perform the calculation:

[0097]

[0098] The simplified formula can be used to calculate the induced current: I≈3.125A. Therefore, when the magnetic field at the center of the energy meter is 0.5mT and the Rogowski coil is located at the center of the energy meter and the center of the interference source, the induced current generated is 3.125A.

[0099] Specifically, the metering product to be output is externally connected to the current sampling element, such as Fig. 9 The metering 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 of the current sampling element and the metering current of the micro-control module, and transmit the sampling data to the micro-control module;

[0101] The magnetic detection module is used to detect the magnetic field to obtain a first magnetic field strength and a magnetic field direction, and transmit the first magnetic field strength and the magnetic field direction to the micro control module;

[0102] The microcontrol module is used to receive the 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, Fig. 9As shown, MCU is a microcontroller module, the metering function module is a metering module, and the magnetic detection function module is a magnetic detection module. Affected by the magnetic field of the interference source, the metering function of the metering product will deviate. At this time, the magnetic detection module detects the magnetic field to obtain the first magnetic field strength and magnetic field direction, and transmits the first magnetic field strength and magnetic field direction to the microcontroller module; the microcontroller module receives the sampling data of the sampling element, the first magnetic field strength and 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; after receiving the sampling data of the current sampling element and the metering current of the microcontroller module, the metering module transmits the sampling data to the microcontroller module.

[0104] In another preferred embodiment of the present invention, the electric energy meter as a measuring product can output the magnitude of the detected current value or voltage value. Fig.10 As shown, in the electric energy meter, the magnitude of the induced current and the magnitude of the detected current are obtained according to the magnetic field strength, the current sampling element and the direction of the current element of the interference source, and then compensation calculation is performed to obtain the actual measured metering current data. The electric energy meter calculates the interference magnetic field at the installation position of the Rogowski coil through the magnetic detection module and the microcontroller module. Due to installation reasons, the Rogowski coil is sleeved on the current line, which affects the current measurement accuracy of the Rogowski coil. The magnetic field is perpendicular to the XZ plane of the magnetic field generated by the actual power line, so the magnetic field detected by the electric energy meter is the vector sum of the actual two mutually perpendicular magnetic fields. The installation position (third position) of the Rogowski coil during installation has been recorded in the electric energy meter. The electric energy meter MCU compensates and offsets the specific induced current generated by the external current sampling element through the corresponding algorithm, and calculates the magnitude of the magnetic field induced current (interference current). When the magnetic field detected by the magnetic induction chip in the electric energy meter is the magnetic field generated by the power line, it means that there is no interference.

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

[0106] Table 2

[0107]

[0108]

[0109] According to the test verification data results, when there is a 0.5mT power frequency magnetic field affecting the Rogowski coil, the average induced current is about 863.3mA. Substituting it into the calculation formula The verification result is correct.

[0110] In another preferred embodiment of the present invention, it is assumed that the power frequency magnetic field detected by the center of the current electric energy meter is 0.5 mT and the current in the actual line measured by the Rogowski coil is 100 A. According to the previous calculation, there is an induced current of 3.125 A in the Rogowski coil. Since the actual current in the line is 100 A, according to the Biot-Savart law, the magnetic field in the vertical direction ( Figure 8 The X-axis direction of the magnetic field generated by the power line (interference source) is 6mT. The current information collected by the electric energy meter is about 103.125A. The magnetic detection module of the electric energy meter detects Figure 8 The magnetic field magnitudes in the X-axis and Z-axis directions of the magnetic field diagram generated by the power line (interference source) are 6mT and 0.5mT respectively. According to the calculation, the electric energy meter program will compensate the actual current: 103.125A-100A: that is: 3.125A, to improve the measurement accuracy, reduce the impact of the magnetic field on the electric energy meter, and improve the measurement accuracy of the electric energy meter. When the Rogowski coil is affected by the power frequency magnetic field, it will induce an interference current I'. The current collected by the electric energy meter through the Rogowski coil is actually 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. The magnetic field detected by the electric energy meter magnetic field detection module and the program processing of the meter can calculate the current I' generated by the magnetic field. After removing the induced interference current, it is the size of I in the actual power line.

[0111] By implementing this embodiment, the first position of the metering product to be output, the first magnetic field strength, the magnetic field direction, the vacuum permeability, the second position of the current element to be measured, the current element length, the current element direction, the third position of the current sampling element, the coil radius and the sampling data can be obtained; according to the first position, the second position, the magnetic field direction and the current element direction, the angle between the metering product to be output and the current element to be measured is calculated; according to 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 angle, the induced current generated by the current sampling element is calculated; according to the sampling data and the induced current, compensation calculation is performed to obtain the metering current of the metering product to be output. Through the parameters such as the angle, magnetic field strength, and position relationship 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, and further compensation calculation 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 fluctuation, thereby improving the anti-interference ability of the electric energy metering product and improving the accuracy of the metering current.

[0112] See also Figure 2 , is a schematic diagram of the structure of an anti-interference system for an electric energy metering product provided by an embodiment of the present invention, comprising:

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

[0114] A metering angle calculation module, used to calculate the angle between the metering product to be output and the current element to be measured according to the first position, the second position, the magnetic field direction and the current element direction;

[0115] an induced current calculation module, configured to calculate, according to the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum magnetic permeability, the coil radius and the angle, to obtain the induced current generated by the current sampling element;

[0116] The metering data output module is used to perform compensation calculation according to the sampling 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 according to the first position, the second position, the direction of the magnetic field and the direction of the current element, including:

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

[0119] A distance calculation submodule, used for calculating the straight-line distance between the metering product to be output and the current element to be measured according to the first position and the second position;

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

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

[0122] a current element current calculation submodule, configured to calculate according to the first magnetic field strength, the first position, the second position, the current element length, the vacuum permeability, and the angle to obtain the current element current;

[0123] A second magnetic field strength calculation submodule, configured to calculate a second magnetic field strength at a current sampling element according to the current element current, the second position, the third position, the current element length, and the vacuum permeability;

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

[0125] The present invention provides an anti-interference system for electric energy metering products. According to a data acquisition module, a first position of a metering product to be output, a first magnetic field strength, a magnetic field direction, a vacuum magnetic permeability, a second position of a current element to be measured, a current element length, a current element direction, a third position of a current sampling element, a coil radius and sampling data are acquired; in a metering angle calculation module, an angle between the metering product to be output and the current element to be measured is calculated according to the first position, the second position, the magnetic field direction and the current element direction; in an induced current calculation module, an induced current generated by the current sampling element is calculated according to the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum magnetic permeability, the coil radius and the angle; finally, in a metering data output module, a compensation calculation is performed according to the sampling data and the induced current to obtain a metering current of the metering product to be output. Through parameters such as the angle between the output metering product and the current element to be measured, the magnetic field strength, and the position relationship, the induced current generated by the current sampling element can be calculated more accurately. Further compensation calculation 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 electric energy metering product and the accuracy of the measured current.

[0126] It should be noted that the system embodiment described above is merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the drawings of the system embodiment provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

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

[0128] Another embodiment of the present invention further 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, wherein the processor implements an anti-interference method for an electric energy metering product as described in the above embodiment when executing the computer program. The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, and a cloud server. The terminal device may include, but is not limited to, a processor and a memory.

[0129] The processor may be a central processing unit (CPU), or other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, and various interfaces and lines are used to connect various parts of the entire terminal device.

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

[0131] Another embodiment of the present invention provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the anti-interference method for electric energy metering products 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 the processor, the steps of each of the above-mentioned method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium.

[0133] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An anti-interference method for electric energy metering products, characterized in that: A microcontroller module applicable to an anti-interference system of an electric energy metering product; an anti-interference method of the electric energy metering product, comprising: Obtaining the first position of the metering product to be output, the first magnetic field strength, the magnetic field direction, the vacuum magnetic permeability, the second position of the current element to be measured, the current element length, the current element direction, the third position of the current sampling element, the coil radius and the sampling data; Calculate the angle between the metering product to be output and the current element to be measured according to the first position, the second position, the direction of the magnetic field and the direction of the current element; Calculate according to the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum magnetic permeability, the coil radius and the angle to obtain the induced current generated by the current sampling element; Compensation calculation is performed according to the sampling data and the induced current to obtain a metering current of the metering product to be output.

2. The anti-interference method for electric energy metering products according to claim 1, characterized in that: The direction of the magnetic field is perpendicular to the direction of the current element; Calculating the angle between the metering product to be output and the current element to be measured according to the first position, the second position, the magnetic field direction, and the current element direction includes: Constructing a spatial rectangular coordinate system by taking the direction of the magnetic field as the horizontal axis of the spatial rectangular coordinate system and taking the direction of the current element as the vertical axis of the spatial rectangular coordinate system; According to the first position and the second position, a straight-line distance between the metering product to be output and the current element to be measured is calculated; The angle between the metering product to be output and the current element to be measured is calculated according to the first position, the straight-line distance and the spatial rectangular coordinate system.

3. The anti-interference method for electric energy metering products according to claim 1, characterized in that: The induced current generated by the current sampling element is obtained by calculating according to the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum magnetic permeability, the coil radius and the angle, including: Calculating according to the first magnetic field strength, the first position, the second position, the current element length, the vacuum magnetic permeability, and the angle to obtain the current element current; Calculating a second magnetic field intensity at a current sampling element according to the current element current, the second position, the third position, the current element length, and the vacuum magnetic permeability; The induced current of the current sampling element is calculated according to the second magnetic field strength, the second position, the third position, the coil radius, and the vacuum magnetic permeability.

4. The anti-interference method for electric energy metering products according to 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 electric energy metering products according to claim 1, characterized in that: The metering 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 of the current sampling element and the metering current of the micro-control module, and transmit the sampling data to the micro-control module; The magnetic detection module is used to detect the magnetic field to obtain a first magnetic field strength and a magnetic field direction, and transmit the first magnetic field strength and the magnetic field direction to the micro control module; The microcontrol module is used to receive the 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 electric energy metering products, characterized in that: include: A data acquisition module, used to acquire the first position of the metering product to be output, the first magnetic field strength, the magnetic field direction, the vacuum magnetic permeability, the second position of the current element to be measured, the current element length, the current element direction, the third position of the current sampling element, the coil radius and the sampling data; A metering angle calculation module, used to calculate the angle between the metering product to be output and the current element to be measured according to the first position, the second position, the magnetic field direction and the current element direction; an induced current calculation module, configured to calculate, according to the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum magnetic permeability, the coil radius and the angle, to obtain the induced current generated by the current sampling element; The metering data output module is used to perform compensation calculation according to the sampling data and the induced current to obtain the metering current of the metering product to be output.

7. The anti-interference system for electric energy metering products according to 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 according to the first position, the second position, the magnetic field direction and the current element direction, including: A spatial coordinate system construction submodule, used to construct a spatial rectangular coordinate system with the magnetic field direction as the horizontal axis of the spatial rectangular coordinate system and the current element direction as the vertical axis of the spatial rectangular coordinate system; A distance calculation submodule, used for calculating the straight-line distance between the metering product to be output and the current element to be measured according to the first position and the second position; The angle calculation submodule is used to calculate the angle between the metering product to be output and the current element to be measured according to the first position, the straight-line distance and the spatial rectangular coordinate system.

8. The anti-interference system for electric energy metering products according to claim 6, characterized in that: The induced current calculation module is used to calculate according to the first magnetic field strength, the first position, the second position, the third position, the current element length, the vacuum magnetic permeability, the coil radius and the angle to obtain the induced current generated by the current sampling element, including: a current element current calculation submodule, configured to calculate according to the first magnetic field strength, the first position, the second position, the current element length, the vacuum permeability, and the angle to obtain the current element current; A second magnetic field strength calculation submodule, configured to calculate a second magnetic field strength at a current sampling element according to the current element current, the second position, the third position, the current element length, and the vacuum permeability; The sampling element calculation submodule is used to calculate the induced current of the current sampling element according to 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 comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, an anti-interference method for an electric energy metering product as described in any one of claims 1 to 5 is implemented.

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, the device where the computer-readable storage medium is located is controlled to execute an anti-interference method for electric energy metering products as described in any one of claims 1 to 5.

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