TMR current transformer

Abstract

The invention discloses a TMR current transformer in the technical field of current measurement, and aims to solve the problems that in the prior art, only measurement of single current can be achieved generally, measurement work of alternating current and direct current is difficult to meet at the same time, and an air gap is prone to being affected by temperature or vibration and the like. The sensor comprises a sensing assembly, a coil assembly, a shell assembly and a signal processing module, the sensing assembly is arranged in the coil assembly, the coil assembly and the signal processing module are both arranged in the shell assembly, and the sensing assembly and the coil assembly are both electrically connected with the signal processing module; the device can be used for accurate measurement of alternating current and direct current, the size of the air gap is accurately controlled through the gap control piece, meanwhile, the TMR sensor is fixed, the air gap and the TMR sensor are prevented from being affected by temperature, vibration and the like, interference of a complex electromagnetic field of a power grid on the TMR sensor is avoided, and the measurement accuracy of the TMR sensor is improved. And the measurement accuracy is ensured.

Description

Technical Field

[0001] This invention relates to a TMR current transformer, belonging to the field of current measurement technology. Background Technology

[0002] Current transformers are key devices for power system control, protection, and metering. DC neutral current transformers need to exhibit the characteristics of low current during bipolar symmetrical operation and high current during unipolar operation, requiring high measurement accuracy across the entire measurement range. Imported zero-flux current transformers based on fluxgate magnetometers are expensive and lack timely after-sales service. With the development of sensor technology, highly sensitive magnetoresistive sensing technology has demonstrated excellent performance in current measurement, meeting the high-precision measurement requirements of DC neutral current transformers across the entire range. Examples include CN116298469B and CN115469137B. However, these technologies are currently only at the principle and method exploration stage, without specifying the specific structural form of the product.

[0003] Existing TMR sensors are typically susceptible to air gap effects from temperature or vibration. Furthermore, due to the high sensitivity of TMR sensors, traditional single-shell shielding cannot effectively prevent interference from the complex electromagnetic fields of the power grid, thus affecting the measurement accuracy of TMR sensors under complex conditions. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a TMR current transformer that can be used for accurate measurement of both AC and DC current. The gap size is precisely controlled by a gap control component, which also serves to fix the TMR sensor, preventing the air gap and the TMR sensor from being affected by temperature and vibration, thus ensuring the measurement accuracy of this application. Through the cooperation of shielding layers, the TMR sensor is protected from different shielding directions. Multi-layered isolation shielding measures prevent interference from the complex electromagnetic field of the power grid on the TMR sensor, ensuring the stability of the TMR sensor during operation.

[0005] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution: The present invention provides a TMR current transformer, including a sensing component, a coil component, a housing component, and a signal processing module. The sensing component is disposed inside the coil component, and both the coil component and the signal processing module are disposed inside the housing component. Both the sensing component and the coil component are electrically connected to the signal processing module. The sensing component includes a magnetic core, a feedback winding is wound around the outer wall of the magnetic core, an air gap is formed on the magnetic core, and a gap control component for fixing the TMR sensor is provided in the air gap; The coil assembly includes a shielding box, and a shielding layer is provided inside the shielding box. The shielding layer is a multi-layered, thin-film, highly magnetically permeable material with insulation between the layers. The shielding box is made of a highly conductive material.

[0006] Furthermore, the gap control component includes a first fixing component and a second fixing component, with a gap plate and a mounting component provided between the first fixing component and the second fixing component. The first fixing component, the second fixing component, the gap plate, and the mounting component cooperate to form a cavity for placing the TMR sensor.

[0007] Furthermore, the shielding box and the shielding layer cooperate to form a cavity for placing the sensing component. A first notch is provided on the shielding layer. When the sensing component is fixed inside the cavity, the TMR sensor is located on one side of the first notch.

[0008] Furthermore, the housing assembly includes a shielding housing, the coil assembly is detachably connected to the inner wall of the shielding housing, the shielding housing has a second notch, and the outer wall of the shielding housing is detachably connected to a junction box for placing the signal processing module on one side of the second notch.

[0009] Furthermore, the number of coil assemblies is multiple.

[0010] Furthermore, all of the coil assemblies are detachably connected to the inner wall of the shielding housing via studs.

[0011] Furthermore, an epoxy separator is provided between two adjacent coil assemblies.

[0012] Furthermore, the signal processing module is detachably connected to the junction box via a module mounting bracket, and the signal processing module is electrically connected to the sensing component via a signal line.

[0013] Furthermore, the junction box is provided with wiring terminals, and the sensing component and the signal processing module are both electrically connected to the wiring terminals.

[0014] Furthermore, the outer wall of the shielding housing is detachably connected to a sleeve, and the outer wall of the shielding housing is detachably connected to a mounting bracket.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: This TMR current transformer can be used for accurate measurement of both AC and DC current. The gap size is precisely controlled by a gap control component, which also serves to fix the TMR sensor, preventing the air gap and the TMR sensor from being affected by temperature and vibration, thus ensuring the measurement accuracy of this application. Through the cooperation of shielding layers, the TMR sensor is protected from different shielding directions. This multi-layered isolation shielding avoids interference from the complex electromagnetic field of the power grid, ensuring the stability of the TMR sensor during operation. Attached Figure Description

[0016] Figure 1 This is a top cross-sectional view of a TMR current transformer according to an embodiment of the present invention; Figure 2 This is a three-dimensional structural diagram of a TMR current transformer according to an embodiment of the present invention; Figure 3 This is a three-dimensional structural diagram of the shielding box provided according to an embodiment of the present invention; Figure 4 This is a three-dimensional structural schematic diagram of a sensing component provided according to an embodiment of the present invention; Figure 5 This is a three-dimensional structural schematic diagram of the clearance control component provided according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the main structure of the sleeve provided according to an embodiment of the present invention.

[0017] In the diagram: 100, Sensing component; 101, Magnet core; 102, TMR sensor; 103, Gap control component; 1031, First fixing component; 1032, Second fixing component; 1033, Gap plate; 1034, Mounting component; 104, Feedback winding; 105, Air gap; 200, Coil assembly; 201, Shielding layer; 202, Shielding box; 203, First notch; 300, Housing assembly; 301, Shielding housing; 302, Junction box; 303, Mounting bracket; 304, Module mounting bracket; 305, Stud; 306, Epoxy partition; 400, Signal processing module; 401, Terminal block. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] like Figures 1-3 As shown, the present invention provides a TMR current transformer, including a sensing component 100, a coil assembly 200, a housing assembly 300, and a signal processing module 400. The sensing component 100 is disposed inside the coil assembly 200, and both the coil assembly 200 and the signal processing module 400 are disposed inside the housing assembly 300. Both the sensing component 100 and the coil assembly 200 are electrically connected to the signal processing module 400. The sensing component 100 includes a magnet. The core 101 has a feedback winding 104 wound around its outer wall. An air gap 105 is formed on the core 101, and a gap control element 103 for fixing the TMR sensor 102 is provided in the air gap 105. The coil assembly 200 includes a shielding box 202, and a shielding layer 201 is provided inside the shielding box 202. The shielding layer 201 is a multi-layered, thin-film, high-permeability magnetic material with insulation between the layers. The shielding box 202 is made of a high-conductivity material.

[0022] Specifically, during operation, the housing assembly 300 can be directly installed at the point to be measured to measure low-voltage current, or it can be installed at the point to be measured through a bushing to measure high-voltage current. This application can be used for precise measurement of AC current, precise measurement of DC current, and precise measurement of current in situations where AC and DC currents are superimposed, with high measurement accuracy across the entire range. The gap control component 103 precisely controls the size of the air gap 105 and simultaneously fixes the TMR sensor 102, preventing temperature-related damage to the air gap 105 and the TMR sensor 102. The shielding layer 201 is composed of one or more layers of thin-film high-permeability magnetic material, fixed inside the shielding box 202, with insulation between the layers to avoid product heating and vibration caused by electromagnetic fields. The shielding box 202 is made of highly conductive material. The shielding layer 201 and the shielding layer 202 can work together to protect the TMR sensor 102 from different shielding directions. Through multi-layer isolation shielding measures, the interference of complex electromagnetic fields of the power grid on the TMR sensor is avoided, ensuring the stability of the TMR sensor 102 during operation.

[0023] Optionally, the magnetic core 101 is a ring structure made of highly magnetic material, and the feedback winding 104 is uniformly wound on the outer wall of the magnetic core 101; the gap control component 103 fixes the TMR sensor 102 at the center of the air gap 105; the magnetic core 101 is used to gather the induced magnetic field according to the measured current, and the TMR sensor 102 is used to output the induced signal according to the induced magnetic field; the signal processing module 400 is used to perform current measurement based on the signals from the sensing component 100 and the coil component 200.

[0024] like Figure 4 and Figure 5 As shown in one embodiment, the gap control component 103 includes a first fixing component 1031 and a second fixing component 1032. A gap plate 1033 and a mounting component 1034 are provided between the first fixing component 1031 and the second fixing component 1032. The first fixing component 1031, the second fixing component 1032, the gap plate 1033 and the mounting component 1034 cooperate to form a cavity for placing the TMR sensor 102.

[0025] Specifically, the first fixing member 1031, the second fixing member 1032, the gap plate 1033, and the mounting member 1034 cooperate to install and fix them at the air gap 105, thereby locking the size of the air gap 105. The TMR sensor 102 is installed inside the cavity to ensure that the TMR sensor 102 is located at the exact center of the air gap 105. Optionally, the mounting member 1034 is detachably connected to the first fixing member 1031 and the second fixing member 1032.

[0026] like Figure 1 and Figure 3 As shown in one embodiment, the shielding box 202 cooperates with the shielding layer 201 to form a cavity for placing the sensing component 100. The shielding layer 201 has a first notch 203. When the sensing component 100 is fixed inside the cavity, the TMR sensor 102 is located on one side of the first notch 203.

[0027] Specifically, the shielding layer 201 is fixed to the inside of the shielding box 202; optionally, the shielding layer 201 and the shielding box 202 are detachably connected; the cavity is annular; the sensing component 100 is fixed in the annular cavity of the shielding layer 201 and the shielding box 202, and the TMR sensor 102 is directly opposite the first notch 203, and wiring can be installed through the first notch 203, ensuring the stability of the structural connection.

[0028] like Figure 1 and Figure 2 As shown, in one embodiment, the housing assembly 300 includes a shielding housing 301, the coil assembly 200 is detachably connected to the inner wall of the shielding housing 301, the shielding housing 301 has a second notch, and the outer wall of the shielding housing 301 is detachably connected to a junction box 302 for placing the signal processing module 400 on one side of the second notch; the number of coil assemblies 200 is multiple; each of the multiple coil assemblies 200 is detachably connected to the inner wall of the shielding housing 301 by studs 305; and an epoxy partition 306 is detachably connected between two adjacent coil assemblies 200.

[0029] Specifically, multiple coil assemblies 200 are detachably connected to the inner wall of the shielding housing 301 via the same stud 305, and the epoxy partition 306 protects two adjacent coil assemblies 200. The TMR sensor 102 in the current transformer proposed in this invention can be replaced by adjusting its position through the junction box 302. If the TMR sensor 102 malfunctions, the junction box 302 can be removed directly, and the sensor can be replaced without disassembling the product, which is convenient for maintenance.

[0030] like Figure 1As shown, in one embodiment, the signal processing module 400 is detachably connected to the junction box 302 via a module mounting bracket 304, and the signal processing module 400 is electrically connected to the sensing component 100 via a signal line; the junction box 302 is provided with a terminal block 401, and both the sensing component 100 and the signal processing module 400 are electrically connected to the terminal block 401; the outer wall of the shielding housing 301 is detachably connected to a mounting bracket 303.

[0031] In use, the shielding housing 301 can be directly installed at the point to be measured using the mounting bracket 303 to measure the low-voltage side current; alternatively, it can be installed at the point to be measured via a through-wall bushing to measure the high-voltage current. Figure 6 As shown.

[0032] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A TMR current transformer, characterized by, The application relates to a sensor coil assembly, which comprises a sensing assembly (100), a coil assembly (200), a shell assembly (300) and a signal processing module (400), the sensing assembly (100) is arranged in the coil assembly (200), the coil assembly (200) and the signal processing module (400) are arranged in the shell assembly (300), and the sensing assembly (100) and the coil assembly (200) are electrically connected with the signal processing module (400). The sensing assembly (100) comprises a magnetic core (101), a feedback winding (104) is arranged on the outer wall of the magnetic core (101), an air gap (105) is formed in the magnetic core (101), and a gap control piece (103) for fixing a TMR sensor (102) is arranged in the air gap (105). The coil assembly (200) comprises a shielding box body (202), a shielding layer (201) is arranged in the shielding box body (202), the shielding layer (201) is a plurality of laminated film-shaped high-permeability materials, insulation isolation is arranged between layers, and the shielding box body (202) is a high-conductivity material.

2. The TMR current transformer of claim 1, wherein, The gap control piece (103) comprises a first fixing piece (1031) and a second fixing piece (1032), a gap plate (1033) and a mounting piece (1034) are arranged between the first fixing piece (1031) and the second fixing piece (1032), and the first fixing piece (1031), the second fixing piece (1032), the gap plate (1033) and the mounting piece (1034) are matched to form a cavity for placing the TMR sensor (102).

3. The TMR current transformer of claim 1, wherein, The shielding box body (202) and the shielding layer (201) are matched to form a cavity for placing the sensing assembly (100), a first notch (203) is formed in the shielding layer (201), and when the sensing assembly (100) is fixed in the cavity, the TMR sensor (102) is located on one side of the first notch (203).

4. The TMR current transformer of claim 1, wherein, The shell assembly (300) comprises a shielding shell (301), the coil assembly (200) is detachably connected with the inner wall of the shielding shell (301), a second notch is formed in the shielding shell (301), and a junction box (302) for placing the signal processing module (400) is detachably connected with the outer wall of the shielding shell (301) on one side of the second notch.

5. The TMR current transformer of claim 4, wherein, The number of the coil assemblies (200) is plural.

6. The TMR current transformer of claim 5, wherein, The coil assemblies (200) are detachably connected with the inner wall of the shielding shell (301) through studs (305).

7. The TMR current transformer of claim 5, wherein, Epoxy partition plates (306) are detachably connected between adjacent two coil assemblies (200).

8. The TMR current transformer of claim 4, wherein, The signal processing module (400) is detachably connected with the junction box (302) through a module mounting rack (304), and the signal processing module (400) is electrically connected with the sensing assembly (100) through a signal line.

9. The TMR current transformer of claim 4, wherein, The terminal block (401) is arranged in the terminal box (302), and the sensing assembly (100) and the signal processing module (400) are electrically connected with the terminal block (401).

10. The TMR current transformer of claim 4, wherein, The outer wall of the shielding shell (301) is detachably connected with a sleeve, and the outer wall of the shielding shell (301) is detachably connected with a mounting bracket (303).

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