Current sensing device

Abstract

The utility model belongs to the technical field of electronic sensing, and particularly discloses a current sensing device. The current sensing device comprises a first PCB type Rogowski coil, a second PCB type Rogowski coil and a third Rogowski coil, wherein the first PCB type Rogowski coil and the second PCB type Rogowski coil are stacked at intervals to form a tubular structure, and the third Rogowski coil is uniformly wound on the tubular structure; and the first PCB type Rogowski coil and the second PCB type Rogowski coil are connected in series according to a stacking sequence and then are connected in series with the third Rogowski coil. The third Rogowski coil and the PCB type coil are combined, and the PCB type coil serves as a winding framework of the third Rogowski coil, so that the induction signal of the Rogowski coil can be increased to the maximum extent in a limited space size, and the sensitivity of current sensing is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electronic sensing, and more particularly, to a current sensing device. BACKGROUND

[0002] More than 50% of the faults in power systems come from insulation faults. During long-term energized operation, insulation equipment is affected by high-voltage electric field, chemical corrosion, mechanical stress and environmental factors, and its performance gradually declines and its insulation strength gradually decreases. The deterioration of insulation performance will cause an increase in leakage current. The increase in leakage current causes the temperature of the insulation equipment to rise, resulting in active loss and thermal collapse, and in severe cases, will lead to damage or explosion, cause insulation breakdown, cause equipment damage, large-scale power outages, and cause huge losses. The insulation performance of equipment is generally evaluated by accurately monitoring the size and phase angle of the leakage current of the equipment and deriving the corresponding parameters. The leakage current is usually very weak, and the Rogowski coil has good linearity, high measurement accuracy, and is isolated from the measured signal, so it has a wide application in high-voltage environments for small current detection.

[0003] As a non-contact current sensor, there are mainly two kinds of Rogowski coils, as shown in the following two figures: Figure 1 One is a traditional Rogowski coil, in which the enameled wire is uniformly wound on a hard or flexible non-magnetic skeleton; and the other is a PCB (Printed Circuit Board) type Rogowski coil, in which the Rogowski coil is printed on a PCB. The mutual inductance coefficient between the Rogowski coil and the measured current conductor is the most critical parameter that determines the measurement accuracy and sensitivity. However, because the two kinds of Rogowski coils do not contain a magnetic core, the mutual inductance coefficient is small, and when detecting the current signal, the induced voltage is very weak, so it is impossible to detect very small currents. CONTENT OF THE INVENTION

[0004] In view of the above defects or improvement needs of the prior art, the present application provides a current sensing device, which aims to solve the technical problem that the existing Rogowski coil cannot detect small currents.

[0005] To achieve the above-mentioned purpose, in a first aspect, the present application provides a current sensing device, comprising: a first PCB type Rogowski coil, a second PCB type Rogowski coil and a third Rogowski coil; wherein the first PCB type Rogowski coil and the second PCB type Rogowski coil are stacked in a tubular structure, and the third Rogowski coil is uniformly wound on the tubular structure; and the first PCB type Rogowski coil and the second PCB type Rogowski coil are connected in series in the stacking order and connected in series with the third Rogowski coil.

[0006] Preferably, the number of the first PCB type Rogowski coil and the second PCB type Rogowski coil is equal.

[0007] Preferably, the winding directions of the first and second PCB-type Rogowski coils are opposite.

[0008] Preferably, the winding positions of the first and second PCB-type Rogowski coils are mirror images of each other.

[0009] Preferably, in the tube-type structure, the deflection angles of the first and second PCB-type Rogowski coils adjacent to each other are different.

[0010] Preferably, the side of the first PCB-type Rogowski coil has positive and negative terminals with a half-hole process, and the side of the second PCB-type Rogowski coil has positive and negative terminals with a half-hole process; in the tube-type structure, the positive / negative terminals of the upper layer are aligned and connected with the negative / positive terminals of the lower layer.

[0011] Preferably, the third Rogowski coil is wound in an interval winding mode of one positive winding and one reverse winding.

[0012] Preferably, the winding fixing unit is located outside the tube-type structure and forms a winding skeleton together with the tube-type structure, and the winding skeleton is used for being uniformly wound by the third Rogowski coil.

[0013] Preferably, the winding fixing unit has uniform comb-shaped slots for limiting the winding position of the coil.

[0014] Preferably, the shielding cover is located inside the shielding cover.

[0015] Preferably, the shielding cover is made of Permalloy.

[0016] Preferably, the signal processing unit is connected to the first input end of the signal processing unit through the series connection of the first, second, and third PCB-type Rogowski coils, and is connected to the second input end of the signal processing unit through the series connection of the first, second, and third PCB-type Rogowski coils.

[0017] Preferably, the signal processing unit is used for collecting an induced signal, amplifying and analog-to-digital converting the induced signal, performing integral operation on the signal in the digital field, restoring the phase of the signal, and accurately measuring the current signal.

[0018] Overall, the above technical solutions conceived by the present application have the following beneficial effects compared with the prior art:

[0019] (1) The application adopts two kinds of PCB type Rogowski coils to form a tube type structure, and a third Rogowski coil is wound around the tube type structure, thereby forming a comprehensive Rogowski coil. The comprehensive Rogowski coil can improve the mutual inductance coefficient of the coil in a limited space, thereby realizing precise measurement of a small current signal.

[0020] (2) In the application, positive and negative terminals with a half-hole process are designed on the edge of the PCB type Rogowski coil. The upper and lower layers of the PCB type Rogowski coil are connected in series through the positive and negative terminals, thereby omitting the connector and reducing the failure risk of the connection part. At the same time, the space between the upper and lower layers of the PCB type Rogowski coil is reduced, more PCB type Rogowski coils can be accommodated in the same space, and the mutual inductance coefficient of the device is effectively improved.

[0021] (3) In the application, the winding direction of the first PCB type Rogowski coil and the second PCB type Rogowski coil is opposite, the winding position is a mirror image, and the adjacent upper and lower layers are deflected and staggered after stacking. Therefore, the axial electromagnetic interference is reduced by being a mirror image, the capacitive coupling between the single PCB boards is reduced by the deflection and staggering of the upper and lower layers, and the self interference is reduced.

[0022] (4) The application is provided with a winding fixing unit with a comb-shaped slot, which can effectively improve the winding process of the third Rogowski coil and ensure the uniformity and consistency of the winding.

[0023] (5) The application is provided with a Permalloy shield, which can reduce the interference of the electric field and the magnetic field on the Rogowski coil in the device, thereby improving the sensing and measuring accuracy of the application. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a schematic diagram of the Rogowski coil proposed in the background technology of the application.

[0025] Figure 2 It is a schematic diagram of a current sensing device provided by the embodiment of the application.

[0026] Figure 3 It is a winding schematic diagram of the first PCB type Rogowski coil and the second PCB type Rogowski coil provided by the embodiment of the application.

[0027] Figure 4 It is a schematic diagram of the first PCB type Rogowski coil and the second PCB type Rogowski coil provided by the embodiment of the application.

[0028] Figure 5 It is an appearance schematic diagram of the winding fixing unit provided by the embodiment of the application.

[0029] Figure 6 It is a schematic diagram of the shield provided by the embodiment of the application.

[0030] Figure 7 is a current sensor device installation and measurement flowchart provided by an embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0032] In the present application, the term " / " describes the "or" relationship, for example, positive / negative, which means positive or negative.

[0033] In the present application, the terms "first" and "second" and the like in the specification and claims are used to distinguish different objects, and are not used to describe the specific order of the objects. For example, the first PCB type Rogowski coil and the second PCB type Rogowski coil are used to distinguish different PCB type Rogowski coils, and are not used to describe the specific order of the PCB type Rogowski coils.

[0034] In the present application, the words "exemplary" or "for example" are used to mean serving as an example, instance, or illustration, any implementation or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or advantageous than other implementations or design solutions. Rather, the use of the words "exemplary" or "for example" is intended to present relevant concepts in a concrete manner.

[0035] In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more, for example, a plurality of Rogowski coils means two or more Rogowski coils, and the like; a plurality of elements means two or more elements, and the like.

[0036] The technical solutions of the present application are further described below in combination with the embodiments of the present application.

[0037] Embodiment 1:

[0038] In the embodiments of the present application, the structure, installation and measurement process of a current sensor device are introduced. Thus, the technical solutions of the present application are further described.

[0039] As Figure 2As shown, the current sensing device of the embodiment of the present application comprises: three first PCB type Rogowski coils, three second PCB type Rogowski coils and one third Rogowski coil; wherein the first PCB type Rogowski coils and the second PCB type Rogowski coils are stacked in a spaced manner to form a tube type structure, that is, the first PCB type Rogowski coils of version A and the second PCB type Rogowski coils of version B are stacked in a spaced manner. In the embodiment, three first PCB type Rogowski coils and three second PCB type Rogowski coils are stacked in a spaced manner to form a tube type structure.

[0040] The present application does not limit the number of first PCB type Rogowski coils and second PCB type Rogowski coils. A plurality of first PCB type Rogowski coils and a plurality of second PCB type Rogowski coils can be stacked in a spaced manner to form a tube type structure. Alternatively, one first PCB type Rogowski coil and one second PCB type Rogowski coil can be stacked in a spaced manner to form a tube type structure. Both of the above options belong to the technical solution of the present application.

[0041] When the number of first PCB type Rogowski coils and second PCB type Rogowski coils is equal, the effect of the present application is optimal.

[0042] In the embodiment, the third Rogowski coil is uniformly wound on the tube type structure; the first PCB type Rogowski coils and the second PCB type Rogowski coils are connected in series according to the stacking order and are connected in series with the third Rogowski coil.

[0043] The winding method of the first PCB type Rogowski coil and the second PCB type Rogowski coil in the embodiment is as shown in Figure 3 , wherein Figure 3 The first PCB type Rogowski coil on the left is wound clockwise, and the second PCB type Rogowski coil on the right is wound counterclockwise. The winding directions of the two coils are opposite. Moreover, the winding positions of the first PCB type Rogowski coil and the second PCB type Rogowski coil are mirror images of each other. In this way, the magnetic field interference in the axial direction perpendicular to the plane can be reduced.

[0044] When the first PCB type Rogowski coil and the second PCB type Rogowski coil are stacked in a spaced manner, the deflection angles of the first PCB type Rogowski coil and the second PCB type Rogowski coil adjacent to each other are different. As shown in Figure 3 , the deflection angle of the first PCB type Rogowski coil on the left is smaller than that of the second PCB type Rogowski coil on the right. The deflection misalignment of the upper and lower layers can effectively reduce the capacitive coupling between the single PCB boards and reduce self interference.

[0045] Meanwhile, the positive terminal and the negative terminal of the half-hole process are designed on the side surface of the first PCB type Rogowski coil, and the positive terminal and the negative terminal of the half-hole process are also designed on the side surface of the second PCB type Rogowski coil. The positive terminal and the negative terminal are connected to the two ends of the PCB type Rogowski coil.

[0046] AsFigure 4 As shown, when the first PCB-type Rogowski coil and the second PCB-type Rogowski coil are stacked with a spacing, the positive / negative terminals of the upper layer are connected in alignment with the negative / positive terminals of the lower layer, thereby connecting the PCB-type Rogowski coil of the upper layer and the PCB-type Rogowski coil of the lower layer in series. In the embodiment of the present application, the series connection of the upper layer and the lower layer is achieved through the positive and negative terminals of the half-hole process, thereby being able to omit the connector, reduce the risk of failure, and at the same time reduce the spacing after the first PCB-type Rogowski coil and the second PCB-type Rogowski coil are stacked, so that more PCB-type Rogowski coils can be accommodated in the same space, and the mutual inductance coefficient of the device is effectively improved.

[0047] The first PCB-type Rogowski coil and the second PCB-type Rogowski coil are stacked with a spacing to form a tube-type structure. As shown, Figure 5 In the embodiment, a hollow barrel-shaped winding fixing unit accommodating tube-type structure is designed, and the winding fixing unit and the internal tube-type structure together serve as a winding skeleton of the third Rogowski coil, and the third Rogowski coil is uniformly wound on the winding skeleton.

[0048] The winding fixing unit has uniform comb-shaped slots, and the third Rogowski coil is wound along the uniform comb-shaped slots. In this way, the uniformity and consistency of winding can be ensured.

[0049] The third Rogowski coil is wound in an interval winding mode of one positive winding and one reverse winding, thereby reducing the axial magnetic field interference.

[0050] As shown, Figure 6 The shielding cover is used to accommodate the first PCB-type Rogowski coil, the second PCB-type Rogowski coil and the third Rogowski coil after they are combined in series as described above. The shielding cover can reduce the interference of electric field and magnetic field on the coils in the device, thereby improving the sensing accuracy of the present application.

[0051] The embodiment of the present application further includes a signal processing unit; one end of the first PCB-type Rogowski coil, the second PCB-type Rogowski coil and the third Rogowski coil after being connected in series is connected to a first input end of the signal processing unit, and the other end is connected to a second input end of the signal processing unit.

[0052] The signal processing unit is used to collect the induced signal, and after the amplification and analog-to-digital conversion of the induced signal, the integral operation of the signal in the digital field is performed, the signal phase is restored, and the current signal is accurately measured.

[0053] Embodiment 2:

[0054] The embodiment of the present application introduces the installation and measurement process of a current sensing device. Thus, the technical solution of the present application is further illustrated. As shown, Figure 7 The specific steps include:

[0055] (1) A plurality of first PCB-type Rogowski coils and a plurality of second PCB-type Rogowski coils are stacked in a tube type structure;

[0056] (2) In the tube type structure, the negative / positive electrode of the upper layer PCB-type Rogowski coil is connected to the positive / negative electrode of the lower layer PCB-type Rogowski coil, and thus the plurality of first PCB-type Rogowski coils and the plurality of second PCB-type Rogowski coils in the tube type structure are sequentially connected in series in the stacking order, as shown in Figure 4

[0057] (3) The stacked and connected tube type structure is placed in a winding fixing unit;

[0058] (4) The enameled wire of the third Rogowski coil is wound along the comb-shaped slot on the winding fixing unit, and is uniformly wound by adopting the interval winding mode of one positive winding and one reverse winding;

[0059] (5) After the third Rogowski coil is wound, the third Rogowski coil is connected in series at the tail end of the tube type structure;

[0060] (6) The first PCB-type Rogowski coil, the second PCB-type Rogowski coil and the third Rogowski coil connected in series are placed in a shielding box, and the two ends of the series-connected coils are led out;

[0061] (7) The two ends of the series-connected coils are connected to a signal processing unit, the signal processing unit collects the sensing signal, and performs signal amplification and analog-to-digital conversion, and then performs signal integration in the digital field to accurately measure the current signal.

[0062] The method can realize the combination of the PCB-type Rogowski coil and the traditional Rogowski coil in a limited space. Thus, the mutual inductance coefficient can be improved in the limited space, and the precise measurement of the small current signal can be realized.

[0063] It should be understood that expressions such as "include" and "may include" used in the present application indicate the presence of the disclosed functions, operations or constituent elements, and do not limit one or more additional functions, operations and constituent elements. In the present application, terms such as "include" and / or "have" can be interpreted to mean that specific features, numbers, operations, constituent elements, components or combinations thereof are present, but cannot be interpreted to exclude the presence or addition of one or more other features, numbers, operations, constituent elements, components or combinations thereof.

[0064] ​In the description of the embodiments of the present application, it should be noted that unless otherwise clearly specified and limited, the term "connection" should be understood broadly, for example, "connection" can be detachable connection, or can be non-detachable connection; can be direct connection, or can be indirect connection through intermediate medium. Among them, "fixed connection" refers to the relative position relationship after connection is unchanged. "Rotary connection" refers to the relative rotation after connection. "Sliding connection" refers to the relative sliding after connection. The orientation language mentioned in the embodiments of the present application, such as "top", "bottom", "inner", "outer", "left", "right", etc., is only the direction of the drawing, therefore, the orientation language used is to better, more clearly illustrate and understand the embodiments of the present application, and is not indicative or implied that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, therefore, it cannot be understood as a limitation on the embodiments of the present application.

[0065] In addition, in the embodiments of the present application, the mathematical concepts mentioned, such as symmetry, equality, parallel, perpendicular, etc. These limitations are all for the current process level, and are not strictly defined in the mathematical sense, and a small amount of deviation is allowed, such as approximately symmetric, approximately equal, approximately parallel, approximately perpendicular, etc. For example, A is parallel to B, which means that A and B are parallel or approximately parallel, and the included angle between A and B can be between 0 degrees and 10 degrees. A is perpendicular to B, which means that A and B are perpendicular or approximately perpendicular, and the included angle between A and B can be between 80 degrees and 100 degrees.

[0066] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A current sensing device, characterized by, The application relates to a PCB type Roshen coil. The first PCB type Roshen coil and the second PCB type Roshen coil are equal in number.

2. The current sensing device of claim 1, wherein, The first PCB type Roshen coil and the second PCB type Roshen coil are opposite in winding direction.

3. The current sensing device of claim 1, wherein, The first PCB type Roshen coil and the second PCB type Roshen coil are mirror images in winding position.

4. The current sensing device of claim 1, wherein, The deflection angles of the first PCB type Roshen coil and the second PCB type Roshen coil are different.

5. The current sensing device of claim 1, wherein, The side of the first PCB type Roshen coil is provided with positive and negative terminals of a half-hole process, and the side of the second PCB type Roshen coil is provided with positive and negative terminals of a half-hole process; the positive / negative terminals of the upper layer are aligned and connected with the negative / positive terminals of the lower layer in the tube type structure.

6. The current sensing device of claim 1, wherein, The third Roshen coil is wound in an interval winding mode of one positive winding and one reverse winding.

7. The current sensing device of claim 1, wherein, The winding fixing unit is located outside the tube type structure and forms a winding framework together with the tube type structure, and the winding framework is used for being uniformly wound by the third Roshen coil.

8. The current sensing device of claim 1, wherein, The winding fixing unit is provided with uniform comb-shaped slots, which are used for limiting the winding position of the coil.

9. The current sensing device of claim 8, wherein, The first PCB type Roshen coil, the second PCB type Roshen coil and the third Roshen coil are located in the shielding cover.

10. The current sensing device of claim 1, wherein, ​

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