Open-close type inductor against vertical magnetic field interference and electric power meter

Abstract

The utility model relates to open and close type anti -vertical magnetic field interference inductor and electric power instrument thereof, including open and close type rogowski coil and inside open and close type annular vertical magnetic field cancellation coil, the vertical magnetic field cancellation coil surrounds the reclamation area equal to the reclamation area that open and close type rogowski coil surrounds, open and close type rogowski coil includes first, second rogowski coil, the vertical magnetic field cancellation coil includes first, second loop segment, first, second rogowski coil all include the connecting end with open and close end located both ends, the connecting end of first, second rogowski coil is mutually electrically connected, and the open and close end of first, second rogowski coil is electrically connected with first loop segment or second loop segment in the inside of each other respectively, and the other end of first, second loop segment is used to form the output end of open and close type anti -vertical magnetic field interference inductor together. In this way, the technical problem that small current detection is vulnerable to external power frequency electromagnetic field interference is solved, and installation and maintenance are convenient.

Description

Technical Field

[0001] This utility model relates to an openable anti-vertical magnetic field interference sensor and its power meter for use in power instruments, and particularly to an openable anti-vertical magnetic field interference sensor and its power meter applicable to the field of power transmission. Background Technology

[0002] In the process of building and developing the national smart grid, electronic instrument transformers, as a core component of primary equipment in the power system, directly determine the accuracy and stability of grid operation status monitoring and are key devices for accurately acquiring critical electrical parameters such as current and voltage. Currently, current transformers remain the mainstream equipment in the field of AC current detection, mainly divided into the following two categories:

[0003] One type is the iron-core coil current transformer, which requires the design of iron core structures of different sizes according to the rated current (In) specifications. It not only has the problems of large size and high production cost, but also the iron core is prone to magnetic saturation, which leads to obvious nonlinearity in output characteristics. Ultimately, the measurement range is limited, and it is usually only suitable for the range of 0.1In to 2In, which is difficult to meet the needs of wide-range current monitoring.

[0004] Another type is the Rogowski coil current sensor (also known as a hollow current transformer or magnetic potential meter). It measures current by uniformly winding a coil onto a non-magnetic frame and then encasing the conductor being measured. It consists of two parts: a Rogowski coil sensing head and a signal integrator / processor circuit. The sensing head, as the core sensing element, establishes a coupling relationship between the captured electromagnetic field and the measured current. This type of sensor has advantages such as small size and low material cost. Its coreless structure also gives it excellent linearity. The measurement range can cover currents from 0.1 In to tens of thousands of amperes or even larger, making it widely used in high-current detection scenarios. However, Rogowski coils have two major limitations: First, they are extremely sensitive to electromagnetic interference, especially power frequency electromagnetic interference. In low-current detection scenarios below a few hundred amperes, external interference signals can easily overwrite the actual measurement signal, causing significant errors. Second, traditional Rogowski coils are integral structures that cannot be disassembled. They can only be installed when the primary current line is not laid or the power is off. If current monitoring or equipment maintenance is required on an already running line, the power must be turned off, which not only affects the continuity of power supply but also increases the complexity and safety risks of on-site operations.

[0005] In summary, in the power sector, especially in demanding scenarios involving public electricity safety and power supply continuity, optimizing the structure and performance of Rogowski coil current transformers to address their weak resistance to external magnetic field interference while overcoming the limitations of installation and maintenance caused by the integrated structure has become a key technical challenge that urgently needs to be solved by those skilled in the art. Utility Model Content

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

[0007] To achieve the above technical objectives, this utility model adopts the following technical approach:

[0008] A retractable vertical magnetic field interference-resistant sensor includes a ring-shaped retractable Rogowski coil and a retractable 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 identical. There are an even number of hollow coils, symmetrically distributed around a circle on the same horizontal plane. The cavities together form a ring-shaped channel. The vertical magnetic field cancelling coil is located at the center of the ring-shaped channel. The area enclosed by the vertical magnetic field cancelling coil is equal to the area enclosed by the Rogowski coil. The retractable... The Rogowski coil includes a first Rogowski coil and a second Rogowski coil that together form a complete circular ring. The vertical magnetic field cancellation coil includes a first loop segment located within the annular channel of the first Rogowski coil and a second loop segment located within the annular channel of the second Rogowski coil. Both the first and second Rogowski coils include a connecting end and an opening / closing end located at both ends. The connecting ends of the first and second Rogowski coils are electrically connected to each other. The opening / closing ends of the first and second Rogowski coils are respectively electrically connected to the first loop segment or the second loop segment located within them. The other ends of the first and second loop segments are used to jointly form the output terminal of the opening / closing anti-vertical magnetic field interference sensor.

[0009] As a further improvement of this utility model, a matching openable pre-positioning bracket is provided inside the openable Rogowski coil. The pre-positioning bracket is used to connect several hollow coils together in series. The pre-positioning bracket includes a semi-circular first pre-positioning bracket and a semi-circular second pre-positioning bracket. The first loop segment is located inside the first pre-positioning bracket and at the center of the annular channel of the first Rogowski coil. The second loop segment is located inside the second pre-positioning bracket and at the center of the annular channel of the second Rogowski coil.

[0010] As a further improvement of this utility model, the first loop segment includes a head end connected to the opening and closing end of the first Rogowski coil and an end end located at the other end of the head end, the end end further extending with a first extension portion; the second loop segment includes a head end connected to the opening and closing end of the second Rogowski coil and an end end located at the other end of the head end, the end end further extending with a second extension portion, the first extension portion and the second extension portion are twisted together to form the output end of the opening and closing anti-vertical magnetic field interference sensor.

[0011] As a further improvement of this utility model, a single hollow coil includes continuously winding single coil layers arranged neatly according to wire diameter on a coil fixture. 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 to each other. The number of single coil layers is odd and ≥3 layers. After one hollow coil is wound, the next identical hollow coil is wound.

[0012] As a further improvement of this utility model, the first Rogowski coil and the second Rogowski coil are wound in a continuous and unidirectional manner. The end of the first Rogowski coil is electrically connected to the beginning of the first loop segment, and the beginning of the second Rogowski coil is electrically connected to the beginning of the second loop segment. The output terminal is located near the beginning of the first Rogowski coil and the end of the second Rogowski coil.

[0013] As a further improvement of this utility model, the beginning of the first Rogowski coil is directly connected to the end of the second Rogowski coil or electrically connected through a beginning-end connecting wire.

[0014] As a further improvement of this utility model, the spacing between each adjacent hollow coil is less than 1-5% of the radius of the Rogowski coil.

[0015] As a further improvement of this utility model, the prepositioning bracket is a positioning soft rubber strip, and the prepositioning bracket has 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.

[0016] As a further improvement of this utility model, the openable anti-vertical magnetic field interference sensor further includes a first housing for accommodating the first Rogowski coil and the first loop segment, and a second housing for accommodating the second Rogowski coil and the second loop segment. The first housing and the second housing are symmetrically arranged and each includes a semi-circular annular bottom wall, an inner wall extending laterally from the inner circle of the bottom wall, an outer wall extending laterally from the outer circle of the bottom wall, and end walls located at both ends connecting the inner wall and the outer wall. The bottom wall, inner wall, outer wall, and end walls form a semi-open semi-circular annular receiving cavity. The first Rogowski coil and the second Rogowski coil are respectively housed in each of the receiving cavities. The inner wall passes through the center of the Rogowski coil to form a primary current passage hole for opening and closing to allow the primary current line to pass through the 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.

[0017] To achieve the above-mentioned technical objectives, the present invention may also employ the following technical methods:

[0018] An electrical meter includes an electrical meter housing and the aforementioned openable anti-vertical magnetic field interference sensor located within the electrical meter housing.

[0019] Compared to existing technologies, the vertical magnetic field cancellation coil of this invention has an area equal to the area enclosed by the Rogowski coil in its openable type anti-vertical magnetic field interference sensor. The openable Rogowski coil includes a first Rogowski coil and a second Rogowski coil that can together form a complete circular ring. The vertical magnetic field cancellation coil includes a first loop segment located within the annular channel of the first Rogowski coil and a second loop segment located within the annular channel of the second Rogowski coil. Both the first and second Rogowski coils include a connecting end and an opening / closing end located at both ends. The connecting ends of the first and second Rogowski coils are electrically connected to each other. The opening / closing ends of the first and second Rogowski coils are respectively electrically connected to the first loop segment or the second loop segment located within them. The other ends of the first and second loop segments are used to jointly form the output terminal of the openable type anti-vertical magnetic field interference sensor. Thus, the Rogowski coil and the vertical magnetic field cancellation coil enable the openable anti-vertical magnetic field interference sensor to cancel external magnetic field interference from all directions as a whole. This solves the technical problem that ordinary Rogowski coils are easily affected by external power frequency electromagnetic fields when used for small current detection, resulting in large measurement errors and failing to reflect the actual current. This breaks through the current limitations of Rogowski coil applications. Furthermore, it can be opened or closed synchronously as needed, making it convenient to install to or disconnect from the next current line. This facilitates current monitoring or equipment maintenance of the operating lines without affecting the continuity of power supply, and significantly reduces the complexity and safety risks of on-site operations. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the openable anti-vertical magnetic field interference sensor of this utility model in the open state;

[0021] Figure 2 This is a schematic diagram of the structure of the openable anti-vertical magnetic field interference sensor of this utility model in the closed state;

[0022] Figure 3 This utility model presents an exploded view of the structure of the opening and closing type anti-vertical magnetic field interference sensor, including the vertical magnetic field cancellation coil and the positioning soft rubber strip.

[0023] Figure 4 A schematic diagram of the combination of the vertical magnetic field cancellation coil and the positioning soft rubber strip in the opening and closing type anti-vertical magnetic field interference sensor of this utility model;

[0024] Figure 5 A schematic diagram of the structure of the Rogowski coil of the opening and closing type anti-vertical magnetic field interference sensor of this utility model;

[0025] Figure 6 This utility model presents a schematic diagram of the combination of a Rogowski coil, a vertical magnetic field cancellation coil, and a positioning soft rubber strip in an openable anti-vertical magnetic field interference sensor.

[0026] Figure 7yes Figure 6 A combined diagram from another angle.

[0027] Figure 8 This utility model presents a schematic diagram of the structure of a hinged anti-vertical magnetic field interference sensor housing.

[0028] Figure 9 This utility model presents a schematic diagram of the structure of a single hollow coil in an openable anti-vertical magnetic field interference sensor.

[0029] Figure label:

[0030] 100 Openable anti-vertical electric field interference sensor

[0031] 103 connecting wires and 10 hollow coils

[0032] Single coil layer 1001, hole 1002

[0033] First Rogowski coil 11, connection terminal 1103

[0034] Opening / closing end 1104, coil start end 1101

[0035] Coil end 1102 Second Rogowski coil 12

[0036] Connecting end 1203 Opening / closing end 1204

[0037] Coil start 1201 Coil end 1202

[0038] The primary current passes through the center 105 of the annular channel 104.

[0039] First segment 211 Head end 2111

[0040] End portion 2112 First extension portion 212

[0041] Second segment 221, head end 2211

[0042] End portion 2212 Second extension portion 222

[0043] First pre-positioning bracket 31, bracket through hole 311

[0044] Second prepositioning bracket 32, bracket through hole 312

[0045] First shell 61, bottom wall 611

[0046] Inner wall 612 Outer wall 613

[0047] End walls 614, 615; Receiving cavity 616

[0048] Coil positioning hole 618 Second housing 62

[0049] Bottom wall 621 Inner wall 622

[0050] Outer wall 623 End walls 624, 625

[0051] Containment cavity 626, coil positioning cavity 628 Detailed Implementation

[0052] 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 present invention.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] Please refer to Figures 1 to 9The diagram shown is a structural schematic of the openable anti-vertical electric field interference sensor 100 of this utility model. This utility model's openable anti-vertical electric field interference sensor 100 includes annularly distributed openable Rogowski coils and annular openable vertical magnetic field cancelling coils located inside the Rogowski coils. The Rogowski coils include a plurality of self-adhesive hollow coils 10 connected end-to-end. Each hollow coil 10 has a hollow hole 1002 inside. The wire diameter, number of turns, number of layers, inner diameter, and outer diameter of each hollow coil 10 are consistent. There are an even number of hollow coils 10, which are symmetrically distributed around a circle on the same horizontal plane. The holes 1002 together form an annular channel 104. The vertical magnetic field cancelling coil is located at the center of the annular channel 104. The area enclosed by the vertical magnetic field cancelling coil is equal to the area enclosed by the Rogowski coils. In this embodiment, the Rogowski coil is continuously wound from enameled wire. The enameled wire has its own adhesiveness or is coated with adhesive, so that the enameled wire sticks together while being wound, preventing it from becoming tangled and improving winding accuracy and efficiency. The Rogowski coil of this invention includes a first Rogowski coil 11 and a second Rogowski coil 12 that together form a complete circular ring. Both the first and second Rogowski coils include connecting ends 1103 and 1203 at both ends and opening / closing ends 1104 and 1204. The connecting ends 1103 and 1203 of the first and second Rogowski coils 11 and 12 are electrically connected to each other. The first and second Rogowski coils 11 and 12 can be opened or closed at the opening / closing ends 1104 and 1204 for installation, housing, or disassembly from the primary current line (not shown). The connecting ends 1103 and 1203 can be integrally connected or electrically connected through a structure such as a beginning and end connecting wire 103. The vertical magnetic field cancelling coil includes a separately arranged first loop segment 211 and a second loop segment 221. The first loop segment 211 is located within the annular channel 104 of the first Rogowski coil 11, and the second loop segment 221 is located within the annular channel 104 of the second Rogowski coil 12. The connecting terminals 1103 and 1203 of the first Rogowski coil 11 and the second Rogowski coil 12 are electrically connected to each other. The opening and closing terminals 1104 and 1204 of the first Rogowski coil 11 and the second Rogowski coil 12 are respectively electrically connected to the first circuit segment 211 or the second circuit segment 221 located within them. Figure 6As shown, the opening / closing end 1104 of the first Rogowski coil 11 is adjacent to the head end 2111 of the first loop segment 211, achieving an electrical connection; the opening / closing end 1204 of the second Rogowski coil 12 is adjacent to the head end 2211 of the second loop segment 221, achieving an electrical connection. The other ends of the first loop segment 211 and the second loop segment 221 are used to jointly form the output terminal of the opening / closing anti-vertical electric field interference sensor 100. That is, after the first loop segment 211 and the second loop segment 221 pass through their respective annular channels 104, their ends 2112 and 2212 further extend to jointly form the output terminal of the opening / closing anti-vertical electric field interference sensor 100, outputting the collected signal to the outside. No magnetic or non-magnetic core needs to be placed inside the hole 1002. The wire diameter, number of turns, number of layers, inner diameter, and outer diameter of each hollow coil 10 are consistent. There are an even number of hollow coils 10, which are arranged symmetrically around a circle on the same horizontal plane. That is, an even number of hollow coils 10 are axially symmetrically distributed. In this way, since the hollow coils 10 are symmetrically distributed around the center of the circle, the spatial position of adjacent hollow coils 10 is "mirror image" 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 interfering magnetic field in adjacent hollow coils 10 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. All the holes 1002 together form a complete annular channel 104. The first loop segment 211 and the second loop segment 221 of the vertical magnetic field cancelling coil connect several hollow coils 10 in series. The first loop segment 211 and the second loop segment 221 are fixed at the center of the annular channel 104. The merged first Rogowski coil 11 and second Rogowski coil 12 together form the Rogowski coil symmetrically distributed around the circle. The primary current of the Rogowski coil can pass through the center 105 to allow the primary current line (not shown). The output terminal can perform electromagnetic induction detection on the current flowing through the primary current line and output a corresponding signal.With this configuration, the openable anti-vertical electric field interference sensor 100 of this invention can better maintain the consistency of the structure and distribution of each hollow coil 10. 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 are distributed, the vertical magnetic field cancellation coil located at the center of the Rogowski coils can better cancel the induced electromotive force generated by the Rogowski coils themselves. Thus, the Rogowski coils and the vertical magnetic field cancellation coil enable the openable anti-vertical electric field interference sensor 100 of this invention to perfectly cancel external magnetic field interference from all directions as a whole, solving the problem of using ordinary Rogowski coils (not shown) for small current detection. This invention overcomes the technical problem of Rogowski coils being highly susceptible to interference from external power frequency electromagnetic fields, leading to significant measurement errors and an inability to accurately reflect actual currents. Furthermore, the hollow interior of the Rogowski coil, without a magnetic or iron core, gives the open-type anti-vertical electric field interference sensor 100 non-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. Its wide frequency response, free from the limitations of eddy current losses, hysteresis losses, and distributed capacitance caused by iron cores, provides a very wide bandwidth (from a few Hz to several MHz, or even higher), enabling accurate measurement of high-frequency currents and fast transient currents (such as lightning strikes and switching operation surges). It can handle surge currents, fast-turn-off currents of power electronic switches, and currents containing rich harmonics; it has good linearity, with the output signal (induced voltage) strictly proportional to the rate of change of the measured current (di / dt). Under constant coil design parameters (such as turns density and cross-sectional area) and without saturation, its response is linear, maintaining a good linear relationship between input (current change rate) and output (voltage) throughout the measurement range, resulting in high measurement accuracy; it has low load effect, with relatively low output impedance, resulting in very small load effect on the measured circuit, almost no impact on the measured current loop, making it easy to connect to the measurement system; it is flexible, lightweight, and easy to install, facilitating installation in space-constrained locations, and the coil itself has good electrical isolation from the measured high-voltage conductor. This design improves operational safety; it has a wide measurement range, allowing the same coil design to cover a very wide current measurement range (from a few amperes to millions of amperes) by adjusting the number of coil turns and other device parameters, without requiring different turns ratios as in traditional CTs; it has no 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; and the first and second Rogowski coils 11 and 12, along with the first circuit segment 211 and the second circuit segment 221, can be opened or closed synchronously as needed, facilitating installation to or removal from the next current line, enabling current monitoring or equipment maintenance of existing lines without affecting the continuity of power supply, and significantly reducing the complexity and safety risks of on-site operations.

[0058] A open-type pre-positioning bracket is matched and penetrated in the open-type Rogowski coil, the pre-positioning bracket is used for connecting a plurality of the hollow coils 10 in series, the pre-positioning bracket comprises a first semicircular pre-positioning bracket 31 and a second semicircular pre-positioning bracket 32, the first return line segment 211 is located in the first pre-positioning bracket 31 and at the center of the annular channel 104 of the first Rogowski coil 11, and the second return line segment 221 is located in the second pre-positioning bracket 32 and at the center of the annular channel 104 of the second Rogowski coil 12. With this arrangement, it can be ensured that the first return line segment 211 and the second return line segment 221 are located at the center of the first and second Rogowski coils 11 and 12, so that the enclosed area of the vertical magnetic field cancellation coil is equal to the enclosed area surrounded by the Rogowski coil, and it is ensured that the first and second Rogowski coils 11, 12, the first return line segment 211 and the second return line segment 221 can enable the open-type anti-vertical electric field interference inductor 100 to cancel external magnetic field interference from various directions as a whole.

[0059] The first return line segment 211 comprises a head end 2111 connected to the opening and closing end 1104 of the first Rogowski coil 11 and a tail end 2112 located at the other end of the head end 2111, and a first extension part 212 further extends from the tail end 2112; the second return line segment 221 comprises a head end 2211 connected to the opening and closing end 1204 of the second Rogowski coil 12 and a tail end 2212 located at the other end of the head end 2211, a second extension part 222 further extends from the tail end 2212, and the first extension part 212 and the second extension part 222 are twisted with each other to jointly form the output end of the open-type anti-vertical electric field interference inductor 100. With this arrangement, the first return line segment 211 and the second return line segment 221 can jointly form the vertical magnetic field cancellation coil, and the mutual twisting of the first extension part 212 and the second extension part 222 can cancel external electromagnetic interference per se, thereby outputting a more accurate detection signal.

[0060] Refer Figure 8 As shown, in the preferred mode of the present utility model, each individual hollow coil 10 of the Rogowski coil comprises a single coil layer 1001 which is continuously wound on an individual coil jig (not shown) and arranged neatly according to wire diameters, after each single coil layer 1001 is wound, the next single coil layer 1001 is reversely wound on the outer side, adjacent inner and outer single coil layers 1001 are arranged neatly with each other, the number of the single coil layers 1001 is an odd number and is greater than or equal to 3 layers; after one hollow coil 10 is wound, the next identical hollow coil 10 is wound. With this arrangement, the wire diameter, number of turns, number of layers, inner diameter and outer diameter of each individual hollow coil 10 are consistent, which ensures the mutual electromagnetic interference cancellation effect and facilitates continuous winding of the Rogowski coil.

[0061] The first Rogowski coil 11 and the second Rogowski coil 12 are wound in a continuous, same direction, meaning they are connected in series with the correct polarity (winding direction), such as... Figure 6 As shown, in this embodiment, the first hollow coil 10 of the first Rogowski coil 11 is wound from the inside out. After completing the first hollow coil 10, the next identical hollow coil 10 is wound clockwise continuously. Similarly, the first hollow coil 10 of the second Rogowski coil 12 is wound from the inside out, and the next identical hollow coil 10 is wound clockwise continuously after completing the first hollow coil 10. In this way, the induced electromotive forces of each hollow coil 10 can cancel each other out after being disturbed by an external magnetic field. The coil start end 1101 of the first Rogowski coil 11 and the coil end 1202 of the second Rogowski coil 12 are directly connected or electrically connected through the start-end connecting wire 103. Direct connection facilitates the integrated production of the first and second Rogowski coils 11 and 12; while separate winding followed by connection through the start-end connecting wire 103 facilitates the installation and fitment of the first and second Rogowski coils 11 and 12 with other components. The coil end 1102 of the first Rogowski coil 11 is electrically connected to the head end 2111 of the first loop segment 211, and the coil beginning 1201 of the second Rogowski coil 12 is electrically connected to the head end 2211 of the second loop segment 221. The output terminal is located near the coil beginning 1101 of the first Rogowski coil 11 and the coil end 1202 of the second Rogowski coil 12. This arrangement allows the first and second Rogowski coils 11 and 12 to form a complete ring, and the first and second loop segments 211 and 221 to form a complete ring. While ensuring resistance to external electromagnetic interference, this arrangement facilitates the openable / closeable installation of the openable / closeable anti-vertical electric field interference sensor 100.

[0062] Each hollow coil 10 of the open-type anti-vertical electric field interference sensor 100 of this invention does not require any core, thus avoiding interference between cores. This results in the spacing between adjacent hollow coils 10 being 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 of the present invention avoids magnetic leakage between adjacent hollow coils 10, improving the detection accuracy and stability of the entire open-type anti-vertical electric field interference sensor 100.

[0063] The pre-positioning bracket is a flexible positioning strip, such as silicone, rubber, or flexible PVC. The pre-positioning bracket has through holes 311 and 312 in its center or on its side. The vertical magnetic field cancelling coil passes through or is held within these through holes 311 and 312. That is, the first loop segment 211 and the second loop segment 221 can pass through or be held within the through holes 311 and 312 of the first pre-positioning bracket 31 and the second pre-positioning bracket 32. This arrangement facilitates the precise installation of the first loop segment 211 and the second loop segment 221. Specifically, the first loop segment 211 and the second loop segment 221 of the vertical magnetic field cancelling coil can also be flexible wires. After the wires are inserted or held in the prepositioning bracket, the prepositioning bracket can be inserted into the hole 1002 of each hollow coil 10, thereby connecting the hollow coils 10 in series. Then, the vertical magnetic field cancelling coil, the prepositioning bracket and each hollow coil 10 are bent to form a uniformly symmetrical ring distribution on the same plane with the axial center.

[0064] The openable anti-vertical electric field interference sensor 100 further includes a first housing 61 for housing the first Rogowski coil 11 and the first loop segment 211, and a second housing 62 for housing the second Rogowski coil 12 and the second loop segment 221. The first housing 61 and the second housing 62 are symmetrically arranged and each includes a semi-circular annular bottom wall 611, 621, inner walls 612, 622 extending laterally from the inner ring of the bottom walls 611, 621, outer walls 613, 623 extending laterally from the outer ring of the bottom walls 611, 621, and end walls 614, 615, 624, 625 connecting the inner walls 612, 622 and the outer walls 613, 623 at both ends. The bottom walls 611, 621, inner walls 612, 622, outer walls 613, 623, and end walls 614, 615, 624, 625 form semi-open, semi-circular annular receiving cavities 616 and 626, respectively. The first Rogowski coil 11 and the second Rogowski coil 12 are respectively received in the receiving cavities 616 and 626. The inner walls 612 and 622 pass through and surround the center of the Rogowski coil to form a primary current passage hole 630 for opening and closing to allow the primary current line to pass through the center of the Rogowski coil and the vertical magnetic field cancelling coil. The receiving cavities 616 and 626 are provided with a plurality of coil positioning holes 618 and 628 for fixing each hollow coil 10. With this configuration, the end walls 614, 615, 624, and 625 can prevent short circuits between adjacent first Rogowski coils 11 and first loop segments 211 and second Rogowski coils 12 and second loop segments 221, respectively. After encapsulating the first Rogowski coils 11 and first loop segments 211 and the second Rogowski coils 12 and second loop segments 221 in two separate housings, they can be easily opened and closed, thus facilitating their installation on or away from the primary current line. This makes it convenient for the installation and maintenance of the openable anti-vertical electric field interference sensor 100.

[0065] The housing can be made of PC with glass fiber, PPS, or PEEK, and the Rogowski coil is encapsulated in epoxy resin within the receiving cavities 616 and 626. This provides the housing with better strength, stability, and corrosion resistance, thereby extending the service life of the entire openable anti-vertical electric field interference sensor 100.

[0066] Preferably, the Rogowski coil comprises 16 or more hollow coils 10. That is, the 16 or more even-numbered hollow coils 10 are evenly and symmetrically distributed in a ring around the axial center on the same plane, thus providing better electromagnetic interference resistance. In other embodiments of this invention, other numbers of hollow coils 10 may also be used.

[0067] The Rogowski coil is used to surround the primary current line, allowing the primary current line to pass through the center of a circle symmetrically distributed around the center of the Rogowski coil. The hollow coil 10 is elongated and arranged parallel to the primary current line. This arrangement, compared to a perfectly circular hollow coil 10, increases the magnetic field area in the axial direction. Specifically, the hollow coil 10 surrounds the primary current line and has a longer parallel length with it, thereby increasing the magnetic field area around the primary current line and improving the current detection intensity.

[0068] This utility model also protects an electric power meter, including a power meter housing and an openable anti-vertical electric field interference sensor 100 located inside the power meter housing. The main core component of the electric power meter lies in the anti-external magnetic field interference capability of the openable anti-vertical electric field interference sensor 100. The ability of the openable anti-vertical electric field interference sensor 100 to resist external magnetic field interference enables the electric power meter to have excellent power data detection accuracy, giving the electric power meter a core competitive advantage in the market.

[0069] The opening and closing type anti-vertical electric field interference sensor 100 of this utility model can be manufactured by the following method, including the following steps:

[0070] Multiple hollow coils 10 are continuously wound from enameled wire and connected in series. Each hollow coil 10 includes a single coil layer 1001 continuously wound on a coil fixture and arranged in a neat manner according to the wire diameter. After each single coil layer 1001 is wound, the next single coil layer 1001 is wound in the opposite direction on the outside. The adjacent inner and outer single coil layers 1001 are arranged neatly with each other. The number of single coil layers 1001 is odd and ≥3 layers.

[0071] On the next coil fixture that is vertically and horizontally offset from the coil fixture, the next hollow coil 10 is continuously wound.

[0072] Multiple coil jigs are arranged in a stepped manner and wound one by one. After the multiple hollow coils 10 are wound on the multiple coil jigs, they are removed from the coil jigs, completing the automated production of the first Rogowski coil 11 and / or the second Rogowski coil 12. In this utility model, the first Rogowski coil 11 and the second Rogowski coil 12 can be continuously wound from a single enameled wire, that is, the coil start end 1101 of the first Rogowski coil 11 and the coil end end 1202 of the second Rogowski coil 12 are integrally connected and wound. In other embodiments, the first Rogowski coil 11 and the second Rogowski coil 12 can also be wound from two enameled wires respectively.

[0073] The first loop segment 211 is threaded or held in the first prepositioning bracket 31 and threaded in the center of the annular channel 104 of the first Rogowski coil 11; the second loop segment 221 is threaded or held in the second prepositioning bracket 32 ​​and threaded in the center of the annular channel 104 of the second Rogowski coil 12.

[0074] The coil start end 1101 of the first Rogowski coil 11 is integrally connected to the coil end 1202 of the second Rogowski coil 12 or electrically connected through the start-end connecting wire 103.

[0075] The first loop segment 211 head end 2111 is electrically connected to the coil end 1102 of the first Rogowski coil 11, and the second loop segment 221 head end 2211 is electrically connected to the coil start end 1201 of the second Rogowski coil 12.

[0076] The end 2112 of the first loop segment 211 and the end 2212 of the second loop segment 221 together form the output terminal of the open-type anti-vertical electric field interference sensor 100;

[0077] Several hollow coils 10, the first loop segment 211, the second loop segment 221, the first prepositioning bracket 31, and the second prepositioning bracket 32 ​​are arranged together to form an openable ring, so that the multiple hollow coils 10 are symmetrically distributed on the same horizontal plane with the circle as the center. The holes 1002 together form an annular channel 104. The first loop segment 211 and the second loop segment 221 are located at the center of the annular channel 104, so that the reclamation area enclosed by the first loop segment 211 and the second loop segment 221 is equal to the reclamation area enclosed by the first and second Rogowski coils 11 and 12.

[0078] Thus, the manufacturing method of the open-type anti-vertical electric field interference sensor 100 can better maintain the consistency of the structure and distribution of each hollow coil 10, 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 are distributed, the vertical magnetic field cancellation coil located at the center of the Rogowski coils can better cancel the induced electromotive force generated by the Rogowski coils themselves, thereby enabling the Rogowski coils and the vertical magnetic field cancellation coil to perfectly cancel each other out as a whole in the open-type anti-vertical electric field interference sensor 100 of this invention. The technology overcomes the limitations of current Rogowski coil applications by eliminating external magnetic field interference from all directions. It solves the technical problem that ordinary Rogowski coils (not shown) are easily affected by external power frequency electromagnetic fields when used for small current detection, resulting in large measurement errors and failing to accurately reflect the actual current. Furthermore, the first and second Rogowski coils 11 and 12, along with the first circuit segment 211 and the second circuit segment 221, can be opened or closed synchronously as needed, facilitating installation to or disconnection from the next current line. This allows for convenient current monitoring or equipment maintenance of existing lines without affecting the continuity of power supply, significantly reducing the complexity and safety risks of on-site operations.

[0079] It is worth noting that in this utility model, 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 utility model.

[0080] 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 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.

[0081] 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.

[0082] 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.

[0083] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A switchable anti-vertical magnetic field interference sensor, characterized in that: The system includes a ring-shaped, openable Rogowski coil and an openable, 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 identical. There are an even number of hollow coils, symmetrically distributed around a circle on the same horizontal plane. The cavities together form a ring-shaped channel. The vertical magnetic field cancelling coil is located at the center of the ring-shaped channel. The area enclosed by the vertical magnetic field cancelling coil is equal to the area enclosed by the Rogowski coil. The openable Rogowski coil includes... The first Rogowski coil and the second Rogowski coil together form a complete circular ring. The vertical magnetic field cancellation coil includes a first loop segment located within the annular channel of the first Rogowski coil and a second loop segment located within the annular channel of the second Rogowski coil. Both the first and second Rogowski coils include a connecting end and an opening / closing end located at both ends. The connecting ends of the first and second Rogowski coils are electrically connected to each other. The opening / closing ends of the first and second Rogowski coils are respectively electrically connected to the first loop segment or the second loop segment located within them. The other ends of the first loop segment and the second loop segment are used to jointly form the output terminal of the opening / closing anti-vertical magnetic field interference sensor.

2. The openable / closing anti-vertical magnetic field interference sensor according to claim 1, characterized in that: The opening and closing Rogowski coil is fitted with a matching opening and closing pre-positioning bracket. The pre-positioning bracket is used to connect several hollow coils together in series. The pre-positioning bracket includes a semi-circular first pre-positioning bracket and a semi-circular second pre-positioning bracket. The first loop segment is located in the first pre-positioning bracket and at the center of the annular channel of the first Rogowski coil. The second loop segment is located in the second pre-positioning bracket and at the center of the annular channel of the second Rogowski coil.

3. The openable / closing anti-vertical magnetic field interference sensor according to claim 1, characterized in that: The first loop segment includes a head end connected to the opening and closing end of the first Rogowski coil and an end end located at the other end of the head end, the end end further extending into a first extension portion; the second loop segment includes a head end connected to the opening and closing end of the second Rogowski coil and an end end located at the other end of the head end, the end end further extending into a second extension portion, the first extension portion and the second extension portion being twisted together to form the output end of the opening and closing anti-vertical magnetic field interference sensor.

4. The openable / closing anti-vertical magnetic field interference sensor according to claim 1, characterized in that: A single hollow coil comprises continuously winding single coil layers arranged neatly according to wire diameter on a coil fixture. After each single coil layer is wound, the next single coil layer is wound in the opposite direction on the outside. Adjacent inner and outer single coil layers are arranged neatly. The number of single coil layers is odd and ≥3 layers. After a hollow coil is wound, the next identical hollow coil is formed.

5. The openable / closing anti-vertical magnetic field interference sensor according to claim 3, characterized in that: The first Rogowski coil and the second Rogowski coil are wound continuously in the same direction. The end of the first Rogowski coil is electrically connected to the beginning of the first loop segment, and the beginning of the second Rogowski coil is electrically connected to the beginning of the second loop segment. The output terminal is located near the beginning of the first Rogowski coil and the end of the second Rogowski coil.

6. The openable / closing anti-vertical magnetic field interference sensor according to claim 1, characterized in that: The beginning of the first Rogowski coil is directly connected to the end of the second Rogowski coil or electrically connected through a beginning-end connecting wire.

7. The openable / closing anti-vertical magnetic field interference sensor according to claim 1, characterized in that: The spacing between each adjacent hollow coil is less than 1-5% of the radius of the Rogowski coil.

8. The openable / closing anti-vertical magnetic field interference sensor according to claim 2, characterized in that: The prepositioning bracket is a positioning soft rubber strip, and the prepositioning bracket has 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.

9. The openable / closing anti-vertical magnetic field interference sensor according to claim 1, characterized in that: The openable anti-vertical magnetic field interference sensor further includes a first housing for housing the first Rogowski coil and the first loop segment, and a second housing for housing the second Rogowski coil and the second loop segment. The first housing and the second housing are symmetrically arranged and each includes a semi-circular annular bottom wall, an inner wall extending laterally from the inner circle of the bottom wall, an outer wall extending laterally from the outer circle of the bottom wall, and end walls at both ends connecting the inner wall and the outer wall. The bottom wall, inner wall, outer wall, and end walls form a semi-open semi-circular receiving cavity. The first Rogowski coil and the second Rogowski coil are respectively housed in each of the receiving cavities. The inner wall passes through the center of the Rogowski coil to form a primary current passage hole for opening and closing to allow the primary current line to pass through the 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.

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

Images