Vertical magnetic field interference resistant inductor, electric power meter thereof and manufacturing method of vertical magnetic field interference resistant inductor

Abstract

The invention relates to a vertical magnetic field interference resistant inductor, an electric power meter and a manufacturing method thereof, the vertical magnetic field interference resistant inductor comprises a Rogowski coil and an annular vertical magnetic field counteracting coil located in the Rogowski coil, the Rogowski coil comprises an even number of self-adhesion hollow coils which are connected in series end to end, the wire diameter, the number of turns, the number of layers, the inner diameter and the outer diameter of each hollow coil are consistent, and the vertical magnetic field counteracting coil is located in the Rogowski coil. The Rogowski coils are arranged in the same horizontal plane and are symmetrically distributed on the same horizontal plane with a circle as the center, hole parts of the hollow coils jointly form an annular channel, the inning area of the vertical magnetic field offset coil is equal to the inning area defined by the Rogowski coils, and a pre-positioning support is arranged in the annular channel in a penetrating and matched mode. The vertical magnetic field counteracting coil is located at the center of the annular channel, and the Rogowski coil and the vertical magnetic field counteracting coil are provided with output ends. Therefore, the technical problem that small current detection is easily interfered by an external power frequency electromagnetic field is solved.

Description

Technical Field

[0001] This invention relates to an anti-vertical magnetic field interference sensor for use in electrical instruments, its power meter and manufacturing method thereof, and particularly to an anti-vertical magnetic field interference sensor, its power meter and manufacturing method thereof applicable to the field of power transmission. Background Technology

[0002] Electronic instrument transformers are a key component of primary equipment. Currently, current transformers are the primary method used for AC current detection.

[0003] There are two main types of current transformers. One type is the iron core coil transformer, which is made in different sizes according to the rated current. Its disadvantages are that it is large in size and high in cost. It is used in iron cores and has magnetic saturation phenomenon and nonlinearity. Therefore, its current measurement range is narrow and it is commonly used for 0.1In to 2In (rated current).

[0004] Another type is the Rogowski coil current sensor. Also known as an air-core transformer or magnetic potential gauge, the Rogowski coil is widely used for measuring large currents. A Rogowski coil is a coil uniformly wound around a non-magnetic frame, surrounding a conductor, and is used to measure the current flowing through the conductor. A Rogowski coil current sensor consists of two main parts: the Rogowski coil sensing head and the subsequent signal integration and processing circuitry. The sensing head is the signal sensing element of the measuring element; it establishes a coupling relationship with the measured current by capturing the electromagnetic field in space. Rogowski coils are characterized by their small size and low material cost, excellent linearity, and wide measurement range, suitable for currents from 0.1 In to tens of thousands of A or even higher. However, they are particularly susceptible to electromagnetic interference, especially power frequency electromagnetic fields. They are typically used for detecting large currents, such as AC currents of several hundred amperes or more. When used for small currents, they are highly susceptible to interference from external power frequency electromagnetic fields. This causes the sampling current output by the Rogowski coil to include not only the measuring current flowing in the measured conductor but also interference signal current generated by the surrounding electromagnetic field. When the measuring current is small, the interference signal current may even cover the measuring current, leading to a large measurement error and failing to accurately reflect the actual current, thus creating certain limitations.

[0005] Therefore, in the power sector, especially under the stringent requirements related to the safety of electricity use for the general public, how to optimize instrument transformers to improve their ability to resist external magnetic field interference is an urgent problem that needs to be studied and solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide an anti-vertical magnetic field interference sensor, its power meter, and its manufacturing method that can resist or eliminate external vertical magnetic field interference in all directions.

[0007] To achieve the above-mentioned technical objectives, the present invention adopts the following technical approach:

[0008] A vertical magnetic field interference-resistant sensor includes a ring-shaped Rogowski coil and a ring-shaped vertical magnetic field cancellation coil located inside the Rogowski coil. The Rogowski coil includes several self-adhesive hollow coils connected end-to-end. Each hollow coil has a hollow cavity inside. The wire diameter, number of turns, number of layers, inner diameter, and outer diameter of each hollow coil are consistent. There are an even number of hollow coils, which are symmetrically distributed around a circle on the same horizontal plane, and the cavities together form a ring channel. The enclosed area of ​​the vertical magnetic field cancellation coil is equal to the enclosed area of ​​the Rogowski coil. A pre-positioning bracket is inserted through the ring channel, and the pre-positioning bracket connects several hollow coils together in series. The vertical magnetic field cancellation coil is fixed on the pre-positioning bracket and located at the center of the ring channel. The Rogowski coil and the vertical magnetic field cancellation coil are provided with output terminals.

[0009] As a further improvement of the present invention, the spacing between each adjacent hollow coil is <0.2mm or less than 1-5% of the radius of the Rogowski coil.

[0010] As a further improvement of the present invention, the prepositioning support is made of a soft material.

[0011] As a further improvement of the present invention, the prepositioning bracket is provided with a bracket through hole in the middle or side, and the vertical magnetic field canceling coil is inserted or held in the bracket through hole.

[0012] As a further improvement of the present invention, the Rogowski coil is used to surround the outside of the primary current line and to allow the primary current line to pass through the center of a circle symmetrically distributed in the center of the Rogowski coil. The hollow coil is long-waisted and is arranged parallel to the primary current line.

[0013] As a further improvement of the present invention, one end of the vertical magnetic field cancelling coil is electrically connected to one end of the Rogowski coil, and the other end of the vertical magnetic field cancelling coil extends into an extension portion, the vertical magnetic field cancelling coil and the extension portion together forming a first output line; the other end of the Rogowski coil is electrically connected to a second output line, and the extension portion of the first output line and the second output line form the output terminal.

[0014] As a further improvement of the present invention, the Rogowski coil includes eight or more of the aforementioned hollow coils.

[0015] As a further improvement of the present invention, the anti-vertical magnetic field interference sensor further includes a housing for accommodating the Rogowski coil and the vertical magnetic field cancellation coil. The housing includes an annular bottom wall, an inner wall extending laterally from the inner circle of the bottom wall, and an outer wall extending laterally from the outer circle of the bottom wall. The bottom wall, inner wall, and outer wall form a semi-open annular receiving cavity. The Rogowski coil is housed in the receiving cavity. The inner wall passes through the center of the Rogowski coil to form a primary current passage hole for a primary current line to pass through the exact center of the Rogowski coil and the vertical magnetic field cancellation coil. The receiving cavity is provided with a coil positioning hole for fixing each hollow coil, and a stepped portion for positioning the vertical magnetic field cancellation coil is provided between adjacent coil positioning holes.

[0016] To achieve the above-mentioned technical objectives, the present invention may also employ the following technical methods:

[0017] An electrical meter includes a housing of the electrical meter and the aforementioned anti-vertical magnetic field interference sensor located within the housing of the electrical meter.

[0018] To achieve the above-mentioned technical objectives, the present invention may also employ the following technical methods:

[0019] A method for manufacturing a vertical magnetic field interference resistant sensor, comprising:

[0020] Multiple hollow coils are continuously wound from a single enameled wire and connected in series. Each hollow coil includes a single coil layer that is continuously wound on a coil fixture and arranged in a neat manner according to the wire diameter. After each single coil layer is wound, the next single coil layer is wound in the opposite direction on the outside. The adjacent inner and outer single coil layers are arranged neatly with each other. The number of single coil layers is odd and ≥3 layers.

[0021] On the next coil fixture that is vertically and horizontally offset from the coil fixture, the next hollow coil is continuously wound.

[0022] Multiple coil jigs are arranged in a stepped manner and wound one by one. After the multiple hollow coils are wound on the multiple coil jigs, they are removed from the coil jigs to complete automated production. A flexible pre-positioning coil support frame is set up to pass through or hold the vertical magnetic field cancelling coil in the pre-positioning coil support frame.

[0023] Align and pass through the holes of each hollow coil, and insert the prepositioning coil support frame, which is equipped with the vertical magnetic field cancelling coil, into the hole.

[0024] Multiple hollow coils, a vertical magnetic field cancelling coil, and a pre-positioning coil support frame are arranged together in a ring, so that the multiple hollow coils are symmetrically distributed on the same horizontal plane with the circle as the center. The holes together form a ring channel, and the vertical magnetic field cancelling coil is located at the center of the ring channel.

[0025] Compared to existing technologies, the Rogowski coil of the anti-vertical magnetic field interference sensor of this invention comprises an even number of self-adhesive hollow coils connected end-to-end. Each hollow coil has the same wire diameter, number of turns, number of layers, inner diameter, and outer diameter, and is symmetrically distributed around a circle on the same horizontal plane. The holes together form an annular channel. The enclosed area of ​​the vertical magnetic field cancellation coil is equal to the enclosed area of ​​the Rogowski coil. A pre-positioning bracket is inserted within the annular channel, connecting several hollow coils in series. The vertical magnetic field cancellation coil is fixed to the pre-positioning bracket and located at the center of the annular channel. Both the Rogowski coil and the vertical magnetic field cancellation coil have output terminals. Thus, the Rogowski coil and the vertical magnetic field cancellation coil enable the anti-vertical magnetic field interference sensor to cancel external magnetic field interference from all directions as a whole. This solves the technical problem that current ordinary Rogowski coils are easily affected by external power frequency electromagnetic field interference when used for small current detection, leading to large measurement errors and failing to accurately reflect the actual current. This overcomes the current limitations of Rogowski coil applications. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the anti-vertical magnetic field interference sensor of the present invention before packaging;

[0027] Figure 2 This is a schematic diagram of the anti-vertical magnetic field interference sensor of the present invention from another angle before packaging;

[0028] Figure 3 yes Figure 2 A schematic diagram of the exploded structure of the shell separated from the middle;

[0029] Figure 4 yes Figure 3 A schematic diagram of the exploded structure after the shell has been removed;

[0030] Figure 5 yes Figure 4 A schematic diagram of the hollow coil in the middle section;

[0031] Figure 6 yes Figure 4 A schematic diagram of the exploded structure after removing the Rogowski coil;

[0032] Figure 7 This is a schematic diagram of the structure of the first and second output lines of the anti-vertical magnetic field interference sensor of the present invention.

[0033] Figure label:

[0034] Anti-vertical electric field interference sensor 100 enameled wire 1

[0035] Rogowski coil 2, hollow coil 20

[0036] Coil start 201 Coil end 202

[0037] The primary current passes through the center 200 of the hole 203.

[0038] Single coil layer 2210 ring channel 204

[0039] Vertical magnetic field cancellation coil 3 prepositioning bracket 30

[0040] Through hole 301 Spacer 302

[0041] First output line 31 coil 311

[0042] Extension section 312 Second output line 32

[0043] Shell 6 bottom wall 61

[0044] Step section 6111 coil positioning hole 610

[0045] 62 output lines on the outer wall, 621 positioning points

[0046] The inner wall 63 has a primary current passing through hole 630.

[0047] Containment cavity 64 Detailed Implementation

[0048] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0049] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0050] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0051] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0052] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0053] Please refer to Figures 1 to 7The diagram shown is a structural schematic of the first embodiment of the anti-vertical magnetic field interference sensor 100 of the present invention. The anti-vertical magnetic field interference sensor 100 of the present invention includes a ring-shaped Rogowski coil 2 and a ring-shaped vertical magnetic field cancellation coil 3 located inside the Rogowski coil 2. The Rogowski coil 2 includes a plurality of self-adhesive hollow coils 20 connected end-to-end. In this embodiment, the Rogowski coil 2 is continuously wound from a single enameled wire 1. The enameled wire 1 is self-adhesive or coated with adhesive, so that the enameled wire 1 adheres to each other while being wound, preventing it from becoming tangled. The hollow coils 20 are wound one by one. The Rogowski coil 2 includes a plurality of hollow coils 20 connected in series. Each hollow coil 20 includes a single coil layer 2210 continuously wound on a coil jig (not shown) arranged neatly according to wire diameter. After each single coil layer 2210 is wound, the next single coil layer 2210 is wound in the opposite direction on the outside. Adjacent inner and outer single coil layers 2210 are arranged neatly. The number of single coil layers 2210 is odd. And ≥3 layers, after one hollow coil 20 is wound, the next hollow coil 20 is wound. After the Rogowski coil 2 is wound, it is removed from the fixture, so that each hollow coil 20 has a hollow hole 203 inside. Therefore, no magnetic or non-magnetic core needs to be set in the hole 203. The wire diameter, number of turns, number of layers, inner diameter and outer diameter of each hollow coil 20 are consistent. There are an even number of hollow coils 20, which are symmetrically distributed around a circle on the same horizontal plane. That is, an even number of hollow coils 20 are axially symmetrically distributed. In this way, since the hollow coils 20 are symmetrically distributed around the center of the circle, the spatial position of adjacent hollow coils 20 is "mirror" or "rotationally symmetrical" with respect to the center of symmetry. When they are connected in series with the correct polarity (winding direction), the induced electromotive force generated by the same vertical interference magnetic field in adjacent hollow coils 20 will form a relationship of equal magnitude and opposite direction. When subjected to external magnetic field interference, the generated induced electromotive force can be uniformly canceled out, achieving better resistance to external magnetic field interference and improving the accuracy and anti-interference of the meter. The holes 203 together form an annular channel 204. The area enclosed by the vertical magnetic field cancelling coil 3 is equal to the area enclosed by the Rogowski coil 2. A pre-positioning bracket 30 is installed in the annular channel 204. The pre-positioning bracket 30 connects several hollow coils 20 together in series. The vertical magnetic field cancelling coil 3 is fixed on the pre-positioning bracket 30 and located at the center of the annular channel 204. The Rogowski coil 2 and the vertical magnetic field cancelling coil 3 are provided with output terminals 31 and 32. The primary current of the Rogowski coil 2, which is symmetrically distributed around the circle, can pass through the center 200 to allow the primary current line (not shown) to pass through. The output terminals 31 and 32 can perform electromagnetic induction detection on the current flowing through the primary current line and output corresponding signals.With this configuration, the anti-vertical magnetic field interference sensor 100 of the present invention can better maintain the consistency of the structure and distribution of each hollow coil 20. It can effectively utilize geometric symmetry and series reverse connection to achieve mutual cancellation of the induced electromotive force of the interference magnetic field. When subjected to magnetic field interference perpendicular to the plane where the Rogowski coils 2 are distributed, the vertical magnetic field cancellation coil 3 located at the center of the Rogowski coils 2 can better cancel the induced electromotive force generated by the Rogowski coils 2 themselves. Thus, the Rogowski coils 2 and the vertical magnetic field cancellation coil 3 enable the anti-vertical magnetic field interference sensor 100 of the present invention to perfectly cancel external magnetic field interference from all directions as a whole. This solves the technical problem that the current ordinary Rogowski coils (not shown) are easily interfered with by external power frequency electromagnetic fields when used for small current detection, resulting in large measurement errors and failing to reflect the actual current. It breaks through the current limitations of Rogowski coil applications. Furthermore, the aforementioned anti-vertical magnetic field interference sensor 100 exhibits no magnetic saturation, making it extremely suitable for measuring very large currents, currents containing DC components (such as short-circuit fault currents and currents in power electronic equipment), and severely distorted currents. It boasts a wide frequency response, free from the limitations of eddy current losses, hysteresis losses, and distributed capacitance inherent in iron cores, possessing a very wide bandwidth (from a few Hz to several MHz, or even higher). This allows for accurate measurement of high-frequency currents, fast transient currents (such as lightning strikes, switching surges, and rapid turn-off currents of power electronic switches), and currents containing abundant harmonics. It also exhibits excellent linearity, with the output signal (induced voltage) strictly proportional to the rate of change (di / dt) of the measured current. Under constant coil design parameters (such as turns density and cross-sectional area) and without saturation, its response is linear. This design ensures a good linear relationship between input (current change rate) and output (voltage) throughout the entire measurement range, resulting in high measurement accuracy. It also features low load effect, with relatively low output impedance, minimizing the load effect on the measured circuit and virtually eliminating any impact on the measured current loop, making it easy to connect to the measurement system. Furthermore, it is flexible, lightweight, and easy to install, facilitating installation in space-constrained locations. The coil itself has good electrical isolation from the measured high-voltage conductor, improving operational safety. It offers a wide measurement range; by adjusting the number of coil turns and other component parameters, the same coil design can cover a very wide current measurement range (from a few amperes to millions of amperes) without requiring different turns ratios as in traditional CTs. Finally, it is free of residual magnetism, leaving no residual magnetism after measurement and not affecting the accuracy of subsequent measurements, making it particularly suitable for measuring non-periodic transient high currents.

[0054] In this invention, the anti-vertical magnetic field interference sensor 100 eliminates the need for any core in each hollow coil 20, preventing interference between cores and ensuring that the spacing between adjacent hollow coils 20 is less than 0.2 mm or less than 1-5% of the radius of the Rogowski coil. Since the gap between adjacent coils is a weak point for external magnetic field interference, especially in mass production where gaps cannot be completely eliminated, the magnetic field will preferentially penetrate through the gap, disrupting the symmetrical cancellation condition. For example, when the gap width reaches 5% of the coil diameter, the interference suppression ratio may drop by more than 20 dB. Furthermore, the gap causes unequal effective cross-sectional areas of adjacent coils (higher magnetic flux density on the gap side), making the induced electromotive force generated by the magnetic field no longer strictly equal and unable to completely cancel each other out. This design avoids magnetic leakage between adjacent hollow coils 20, improving the detection accuracy and stability of the entire anti-vertical magnetic field interference sensor 100.

[0055] In a preferred embodiment of the present invention, the pre-positioning bracket 30 is made of a soft material, such as silicone, rubber, or soft PVC. This arrangement facilitates the insertion or holding of the vertical magnetic field cancellation coil 3, ensuring that the vertical magnetic field cancellation coil 3 is stably positioned at the center of each hole 203 of the Rogowski coil 2. Specifically, the vertical magnetic field cancellation coil 3 can also be a soft wire. After the wire is inserted or held in the pre-positioning bracket 30, the pre-positioning bracket 30 can be inserted into the holes 203 of each hollow coil 20, thereby connecting the hollow coils 20 in series. Then, the vertical magnetic field cancellation coil 3, the pre-positioning bracket 30, and each hollow coil 20 are bent to form a uniformly symmetrical ring distribution on the same plane with an axial center.

[0056] The prepositioning bracket 30 has a protruding spacer 302 on one side, which is located between two adjacent hollow coils 20. This arrangement facilitates the positioning of each hollow coil 20 at its corresponding position on the prepositioning bracket 30, preventing displacement and thus satisfying the strict geometric symmetry of the Rogowski coil 2. This ensures that each hollow coil 20 has the same "viewpoint" to the vertical magnetic field, achieving mutual cancellation of the induced electromotive forces of the interfering magnetic fields.

[0057] The prepositioning bracket 30 has a bracket through hole 301 in its middle or on its side, and the vertical magnetic field canceling coil 3 passes through or is held in the bracket through hole 301. That is, when the prepositioning bracket 30 has a through hole 301 in its middle, the vertical magnetic field canceling coil 3 passes through the through hole 301; when the prepositioning bracket 30 has a through hole 301 on its side, the vertical magnetic field canceling coil 3 passes through the through hole 301. Figure 4As described above, the vertical magnetic field cancellation coil 3 is laterally clamped within the through hole 301. Since the overall Rogowski coil 2 is relatively small in size, the pre-positioning bracket 30 itself is small in size. Compared with the way of passing through, the lateral clamping method can be more convenient for the clamping and positioning of the vertical magnetic field cancellation coil 3 on the pre-positioning bracket 30.

[0058] The Rogowski coil 2 is used to surround the outside of the primary current line and to allow the primary current line to pass through the center of the circle that is symmetrically distributed about the center of the Rogowski coil 2. The hollow coil 20 is long-waisted and is arranged parallel to the primary current line. With such an arrangement, compared with a circular hollow coil 20, the long-waisted hollow coil 20 can increase the magnetic induction area in the axial direction. That is, the hollow coil 20 surrounds the outside of the primary current line and has a longer parallel length with the primary current line, thereby increasing the magnetic induction area for the primary current line and improving the current detection intensity for the primary current line.

[0059] As shown Figure 3 As shown, one end of the vertical magnetic field cancellation coil is electrically connected to one end of the Rogowski coil 2. That is, the end 202 of the winding coil of the Rogowski coil 2 is wound around the head of the vertical magnetic field cancellation coil 3. After the vertical magnetic field cancellation coil 3 forms a loop portion 311 within the pre-positioning bracket 30, the other end of the loop portion 311 further extends to form an extension portion 312. The vertical magnetic field cancellation coil 3 and the extension portion 312 together form the first output line 31, that is, the loop portion 311 and the extension portion 312 together form the first output line 31; the start end 201 of the coil of the Rogowski coil 2 is wound and electrically connected to the second output line 32. The extension portion 312 of the first output line 31 and the second output line 32 are arranged in parallel or twisted together to form the output terminals 31, 32. With such an arrangement, the vertical magnetic field cancellation coil 3 and the Rogowski coil 2 can be connected in series with each other and transmit the detection signal outward through the output terminals 31, 32. Preferably, the output terminals 31, 32 are preferably multi-strand wires, such as UL1569 or UL3266 wire gauges 26#, 28# cable models.

[0060] Preferably, the Rogowski coil 2 includes more than 8 of the hollow coils 20. That is, more than 8 even-numbered hollow coils 20 are evenly symmetrically distributed in a ring shape with the axial center on the same plane. Thus, it has better anti-electromagnetic interference ability. In other embodiments of the present invention, it can also be other numbers of the hollow coils 20.

[0061] The anti-vertical magnetic field interference sensor 100 further includes a housing 6 for accommodating the Rogowski coil 2 and the vertical magnetic field cancellation coil 3. The housing 6 includes an annular bottom wall 61, an inner wall 63 extending laterally from the inner circle of the bottom wall 61, and an outer wall 62 extending laterally from the outer circle of the bottom wall 61. The bottom wall 61, the inner wall 63, and the outer wall 62 form a semi-open annular receiving cavity 64. The Rogowski coil 2 is accommodated in the receiving cavity 64. The inner wall 63 passes through the center of the Rogowski coil 2 to form a primary current passage hole 630 for allowing the primary current line to pass through the exact center of the Rogowski coil 2 and the vertical magnetic field cancellation coil 3. The receiving cavity 64 is provided with a coil positioning hole 610 for fixing each hollow coil 20. A step portion 6111 for positioning the vertical magnetic field cancellation coil 3 is provided between adjacent coil positioning holes 610. With this configuration, the receiving cavity 64 of the housing 6 can more securely house the Rogowski coil 2 and the vertical magnetic field cancellation coil 3, allowing the primary current line to pass precisely through the center of the Rogowski coil 2 and the vertical magnetic field cancellation coil 3, thereby accurately sensing the flow information of the primary current line. Furthermore, the uniformly sized hollow coils 20 of the Rogowski coil 2 are evenly arranged around the primary current line to cancel the induced electromotive force generated by external magnetic field interference. Similarly, the vertical magnetic field cancellation coil 3 is evenly arranged around the primary current line to cancel the induced electromotive force generated by external vertical magnetic field interference. The coil positioning holes 610 can precisely hold and accommodate a single hollow coil 20, ensuring that each hollow coil 20 is evenly distributed as required above. This guarantees that the positions of the Rogowski coil 2 and the vertical magnetic field cancellation coil 3 are fixed before and after encapsulation, thus effectively preventing external electromagnetic interference from affecting measurement accuracy. The outer wall 62 is also provided with output line positioning holes 621 for fixing the first output line 31 and the second output line 32.

[0062] The housing 6 can be made of PC with glass fiber, PPS, or PEEK, and the Rogowski coil 2 is encapsulated in epoxy resin within the receiving cavity 64. This provides the housing 6 with better strength, stability, and corrosion resistance, thereby extending the overall service life of the vertical magnetic field interference sensor 100.

[0063] This invention also protects an electrical meter, including a power meter housing and an anti-vertical magnetic field interference sensor 100 located within the power meter housing. The core component of the power meter lies in the anti-vertical magnetic field interference sensor 100's resistance to external magnetic field interference. The anti-vertical magnetic field interference sensor 100's ability to resist external magnetic field interference enables the power meter to have excellent power data detection accuracy, giving it a core competitive advantage in the market.

[0064] A method for manufacturing a vertical magnetic field interference resistant sensor 100, comprising the following steps:

[0065] Multiple hollow coils 20 are continuously wound from a single enameled wire 1 and connected in series. Each hollow coil 20 includes a single coil layer 2210 continuously wound on a coil fixture, arranged in a straight line according to wire diameter. After each single coil layer 2210 is wound, the next single coil layer 2210 is wound in the opposite direction on the outside. The adjacent inner and outer single coil layers 2210 are arranged in a straight line. The number of single coil layers 2210 is odd and ≥3 layers.

[0066] On the next coil fixture that is vertically and horizontally offset from the coil fixture, the next hollow coil 20 is continuously wound.

[0067] Multiple coil jigs are arranged in a stepped manner and wound one by one. After the multiple hollow coils 20 are wound on the multiple coil jigs, they are removed from the coil jigs to complete automated production. A flexible pre-positioning coil support frame is set up to pass through or hold the vertical magnetic field cancelling coil 3 in the pre-positioning coil support frame.

[0068] Align and pass through the holes 203 of each hollow coil 20, and pass through the prepositioning coil support frame with the vertical magnetic field cancelling coil 3 in the holes 203.

[0069] Multiple hollow coils 20, vertical magnetic field cancelling coils 3, and prepositioning coil support frame are arranged together in a ring, so that multiple hollow coils 20 are symmetrically distributed on the same horizontal plane with the circle as the center. The holes 203 together form an annular channel 204, and the vertical magnetic field cancelling coil 3 is located at the exact center of the annular channel 204.

[0070] Thus, the manufacturing method of the anti-vertical magnetic field interference sensor 100 can better maintain the consistency of the structure and distribution of each hollow coil 20, and can effectively utilize geometric symmetry and series reverse connection to achieve mutual cancellation of the induced electromotive force of the interference magnetic field. When subjected to magnetic field interference perpendicular to the plane where the Rogowski coils 2 are distributed, the vertical magnetic field cancellation coil 3 located at the center of the Rogowski coils 2 can better cancel the induced electromotive force generated by the Rogowski coils 2 themselves. Thus, the Rogowski coils 2 and the vertical magnetic field cancellation coil 3 enable the anti-vertical magnetic field interference sensor 100 of the present invention to perfectly cancel external magnetic field interference from all directions as a whole. This breaks through the current limitations of Rogowski coil applications and solves the technical problem that ordinary Rogowski coils (not shown) are easily interfered with by external power frequency electromagnetic fields when used for small current detection, resulting in large measurement errors and failing to reflect the actual current normally.

[0071] Preferably, the Rogowski coil 2 is continuously wound from the same enameled wire 1. This arrangement facilitates the manufacturing of the Rogowski coil 2 and ensures consistency in the structural parameters of each hollow coil 20, while also helping to cancel out the induced electromotive force generated between the hollow coils 20 due to external magnetic field interference.

[0072] It is worth noting that in this invention, the order of the above steps is not limited and can be adjusted according to the actual situation, all of which are within the protection scope of this invention.

[0073] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0074] The directional terms used in the various technical features described in the above embodiments, such as front, back, left, right, up, and down, are used only for the convenience of describing and understanding the various technical features, and do not constitute a limitation on specific directions in the actual use of the technical solution.

[0075] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A sensor resistant to vertical magnetic field interference, characterized in that: The device includes a ring-shaped Rogowski coil and a ring-shaped vertical magnetic field cancelling coil located inside the Rogowski coil. The Rogowski coil comprises several self-adhesive hollow coils connected end-to-end. Each hollow coil has a hollow cavity inside. The wire diameter, number of turns, number of layers, inner diameter, and outer diameter of each hollow coil are consistent. There are an even number of hollow coils, which are symmetrically distributed around a circle on the same horizontal plane, and the cavities together form a ring-shaped channel. The enclosed area of ​​the vertical magnetic field cancelling coil is equal to the enclosed area of ​​the Rogowski coil. A pre-positioning bracket is inserted through the ring-shaped channel, and the pre-positioning bracket connects several hollow coils together in series. The vertical magnetic field cancelling coil is fixed on the pre-positioning bracket and located at the center of the ring-shaped channel. Both the Rogowski coil and the vertical magnetic field cancelling coil have output terminals.

2. The anti-vertical magnetic field interference sensor according to claim 1, characterized in that: The spacing between each adjacent hollow coil is <0.2mm or less than 1-5% of the radius of the Rogowski coil.

3. The anti-vertical magnetic field interference sensor according to claim 1, characterized in that: The prepositioning bracket is made of a soft material.

4. The anti-vertical magnetic field interference sensor according to claim 1, characterized in that: The prepositioning bracket has a bracket through hole in the middle or on the side, and the vertical magnetic field canceling coil is inserted or held in the bracket through hole.

5. The anti-vertical magnetic field interference sensor according to claim 1, characterized in that: The Rogowski coil is used to surround the outside of the primary current line and to allow the primary current line to pass through the center of a circle symmetrically distributed in the center of the Rogowski coil. The hollow coil is long-waisted and is arranged parallel to the primary current line.

6. The anti-vertical magnetic field interference sensor according to claim 1, characterized in that: One end of the vertical magnetic field cancelling coil is electrically connected to one end of the Rogowski coil, and the other end of the vertical magnetic field cancelling coil extends into an extension portion, which together form a first output line; the other end of the Rogowski coil is electrically connected to a second output line, and the extension portion of the first output line and the second output line form the output terminal.

7. The anti-vertical magnetic field interference sensor according to claim 1, characterized in that: The Rogowski coil comprises eight or more of the aforementioned hollow coils.

8. The anti-vertical magnetic field interference sensor according to claim 1, characterized in that: The anti-vertical magnetic field interference sensor also includes a housing for housing the Rogowski coil and the vertical magnetic field cancellation coil. The housing includes an annular bottom wall, an inner wall extending laterally from the inner circle of the bottom wall, and an outer wall extending laterally from the outer circle of the bottom wall. The bottom wall, inner wall, and outer wall form a semi-open annular receiving cavity. The Rogowski coil is housed in the receiving cavity. The inner wall passes through the center of the Rogowski coil to form a primary current passage hole for the primary current line to pass through the exact center of the Rogowski coil and the vertical magnetic field cancellation coil. The receiving cavity is provided with coil positioning holes for fixing each hollow coil, and a stepped portion for positioning the vertical magnetic field cancellation coil is provided between adjacent coil positioning holes.

9. An electrical meter, characterized in that: It includes a power meter housing and a vertical magnetic field interference sensor according to any one of claims 1 to 8 located inside the power meter housing.

10. A method for manufacturing a vertical magnetic field interference resistant sensor, for manufacturing the vertical magnetic field interference resistant sensor according to any one of claims 1 to 8, comprising: Multiple hollow coils are continuously wound from a single enameled wire and connected in series. Each hollow coil includes a single coil layer that is continuously wound on a coil fixture and arranged in a neat manner according to the wire diameter. After each single coil layer is wound, the next single coil layer is wound in the opposite direction on the outside. The adjacent inner and outer single coil layers are arranged neatly with each other. The number of single coil layers is odd and ≥3 layers. On the next coil fixture that is vertically and horizontally offset from the coil fixture, the next hollow coil is continuously wound. Multiple coil jigs are arranged in a stepped manner and wound one by one. After the multiple hollow coils are wound on the multiple coil jigs, they are removed from the coil jigs to complete automated production. A flexible pre-positioning coil support frame is set up to pass through or hold the vertical magnetic field cancelling coil in the pre-positioning coil support frame. Align and pass through the holes of each hollow coil, and insert the prepositioning coil support frame, which is equipped with the vertical magnetic field cancelling coil, into the hole. Multiple hollow coils, a vertical magnetic field cancelling coil, and a pre-positioning coil support frame are arranged together in a ring, so that the multiple hollow coils are symmetrically distributed on the same horizontal plane with the circle as the center. The holes together form a ring channel, and the vertical magnetic field cancelling coil is located at the center of the ring channel.

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