A current measuring device for power distribution transmission lines

Abstract

This invention discloses a current measuring device for power distribution transmission lines, belonging to the technical field of current measuring devices. It includes a housing and a magnetic ring. The housing has a wire hole, and the magnetic ring is disposed inside the housing and coaxial with the wire hole. Multiple TMR magnetic field sensors are arranged in a circular array on the circumferential side of the magnetic ring. The housing also houses a miniature power supply and a wireless communication module. The miniature power supply is electrically connected to the wireless communication module and each TMR magnetic field sensor, and the wireless communication module is electrically connected to each TMR magnetic field sensor. The housing and the magnetic ring are a symmetrically joined structure about the wire hole axis. At least one clamping component is provided inside the wire hole to keep the cable under test coaxial with the magnetic ring. This invention can be stably installed on cables, and the clamping component can not only clamp cables of different diameters but also keep the clamped cable coaxial with the magnetic ring, thus adapting to complex and diverse power distribution lines and significantly improving measurement accuracy.

Description

Technical Field

[0001] This invention relates to the field of current measuring device technology, specifically to a current measuring device for power distribution transmission lines. Background Technology

[0002] TMR (Transmission Magnetism) magnetic field sensor technology is relatively mature and has been applied in the field of current measurement. Its principle is based on a non-contact current sensor technology developed using the magnetic tunnel junction effect. Because TMR magnetic field sensors measure spatial magnetic fields, their dynamic range often far exceeds the magnetic field strength generated by power transmission lines, almost eliminating magnetic saturation. However, the high sensitivity of TMR magnetic field sensors to magnetic fields also means that the background magnetic field around actual transmission lines and interfering magnetic fields from other lines have a significant impact on the results, making it difficult to directly apply TMR magnetic field sensors to real-time current measurement of power transmission lines.

[0003] For example, the invention patent application with publication number CN119959606A discloses an integrated voltage and current intelligent sensing device and method based on insulators. Its current sensing unit utilizes the magnetic focusing ability of an open magnetic ring air gap and optimized design of the magnetic ring structure parameters to improve magnetic field measurement sensitivity, placing a TMR chip on the opening of the magnetic ring body. A multi-level magnetic ring structure is used to optimize magnetic focusing performance and anti-interference capability.

[0004] However, the above-mentioned devices still have shortcomings when facing the current measurement conditions of distribution network lines: First, on suspended distribution network transmission lines, components such as magnetic rings need to rely on insulators for stable installation, which has limitations; Second, once the measuring device is freed from the insulator, it is prone to slippage and rotation due to instability of the center of gravity, making it difficult to install stably on the cable, especially difficult to adapt to cables of different diameters and models, and it is difficult to ensure the coaxiality of the cable and the magnetic ring, which will produce errors in the measurement results and make it difficult to adapt to complex and diverse distribution network lines. Summary of the Invention

[0005] The purpose of this invention is to provide a current measuring device for power distribution transmission lines, so as to solve the problems in the prior art where current measuring devices are difficult to install stably on cables of different diameters and where it is difficult to ensure the coaxiality of the cable and the magnetic ring.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a current measuring device for power distribution transmission lines, comprising: a housing and a magnetic ring; the housing has a wire hole; the magnetic ring is disposed inside the housing and coaxial with the wire hole; a plurality of TMR magnetic field sensors arranged in a circular array are disposed on the circumferential side of the magnetic ring; the measuring axis of each TMR magnetic field sensor is consistent with the axis of the magnetic ring; a miniature power supply and a wireless communication module are also disposed inside the housing; the miniature power supply is electrically connected to the wireless communication module and each TMR magnetic field sensor; the wireless communication module is electrically connected to each TMR magnetic field sensor; the housing and the magnetic ring are a spliced ​​structure symmetrical about the axis of the wire hole; at least one clamping component is provided inside the wire hole to keep the cable under test coaxial with the magnetic ring.

[0007] Furthermore, the magnetic ring has a U-shaped outer opening on its periphery, and the TMR magnetic field sensor is connected to the U-shaped outer opening through an insulating component.

[0008] Furthermore, the two parts of the outer shell that are spliced ​​together are a first shell and a second shell. A hinge support is rotatably connected to the first shell. The hinge support is slidably connected to the second shell in a direction perpendicular to the splicing surface of the second shell. An elastic element is provided between the second shell and the hinge support.

[0009] Furthermore, the clamping assembly includes a first wire clamp, a second wire clamp, and a centering mechanism. The first wire clamp is elastically slidably connected within the first housing, and the second wire clamp is elastically slidably connected within the second housing. The first wire clamp and the second wire clamp move synchronously in opposite directions through the centering mechanism to clamp the cable with the relative wire hole centered.

[0010] Furthermore, at least one first guide rod is fixedly connected to the first housing, and the first wire clamp is slidably sleeved on the first guide rod through the through hole thereon. A first spring is sleeved on the first guide rod, and the elastic force of the first spring acts on the first wire clamp in the direction close to the axis of the wire hole.

[0011] Furthermore, the centering mechanism includes a first sleeve, a second sleeve, and a plug rod. The first sleeve is slidably connected inside the first housing and is slidably connected to the first inclined groove on the first wire clamp via a first sliding post fixedly connected to it. The second sleeve is slidably connected inside the second housing and is slidably connected to the second inclined groove on the second wire clamp via a second sliding post fixedly connected to it. The plug rod is elastically slidably connected to one end of the second sleeve. When the second housing rotates to align with the first housing, the plug rod is inserted into the first sleeve. During the process of the second housing sliding closer to the first housing, the first wire clamp and the second wire clamp elastically abut against the cable under test and separate synchronously.

[0012] Furthermore, a third spring is provided inside the second sleeve, and the elastic force of the third spring causes the insertion rod to extend outward from the second sleeve.

[0013] Furthermore, an operating rod is fixedly connected to the insertion rod, with one end of the operating rod extending to the outside of the second housing.

[0014] Furthermore, the first sleeve includes a smooth cylindrical section and a threaded sleeve section connected together. The insert rod is provided with external threads. After the insert rod is inserted into the smooth cylindrical section, the insert rod and the threaded sleeve section are engaged by rotating the operating rod.

[0015] Furthermore, there are two clamping components, distributed on both sides of the magnetic ring.

[0016] Compared with the prior art, the power distribution line current measuring device provided by the present invention designs the shell and the magnetic ring into a spliced ​​structure that is symmetrical about the axis of the wire hole, and sets a clamping component in the wire hole to keep the cable under test and the magnetic ring coaxial. This allows the device to be stably installed on the cable. Moreover, the clamping component can not only clamp cables of different diameters, but also keep the clamped cable in a coaxial state with the magnetic ring, thus adapting to complex and diverse power distribution lines, and significantly improving the measurement accuracy. Attached Figure Description

[0017] To provide a clearer description of the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the embodiments will be briefly introduced below.

[0018] Figure 1 A schematic diagram of the structure when the outer casing is fully opened, provided for an embodiment;

[0019] Figure 2 This is a schematic diagram of the structure when the first housing and the second housing are aligned, as provided in the embodiment.

[0020] Figure 3 A front view of the structure when the first housing and the second housing are aligned, provided for an embodiment;

[0021] Figure 4 A top view of the structure when the first housing and the second housing are aligned, provided for an embodiment;

[0022] Figure 5 for Figure 4 Cross-sectional view along the BB line;

[0023] Figure 6 for Figure 4 Isometric sectional view along line BB;

[0024] Figure 7 For reality Figure 4 Cross-sectional view along line AA;

[0025] Figure 8 This is a structural diagram of the cable clamping method provided in the embodiment;

[0026] Figure 9 A front view of the structure when clamping the cable as provided in the embodiment;

[0027] Figure 10 A top view of the structure when clamping the cable as provided in the embodiment;

[0028] Figure 11 for Figure 10 Cross-sectional view along the DD line;

[0029] Figure 12 for Figure 10 Isometric sectional view along line DD;

[0030] Figure 13 For reality Figure 10 Cross-sectional view along the CC line.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. First housing; 2. Second housing; 3. Wire hole; 4. First magnetic ring; 5. Second magnetic ring; 6. TMR magnetic field sensor; 7. Miniature power supply; 8. Wireless communication module; 9. Clamping assembly; 91. First wire clamp; 92. First guide rod; 93. First spring; 94. Sleeve section; 95. Screw sleeve section; 96. First connecting rod; 97. First sliding column; 98. First inclined groove; 99. Second wire clamp; 910. Second guide rod; 911. Second spring; 912. Second sleeve; 913. Second connecting rod; 914. Second sliding column; 915. Second inclined groove; 916. Insert rod; 917. Third spring; 918. Operating lever; 10. Hinge support; 11. Elastic element. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0034] Please see Figures 1-13This invention provides a current measuring device for power distribution lines, comprising a housing and a magnetic ring. The housing has a circular wire hole 3 for cables to pass through. The magnetic ring is a circular magnetic conductor located inside the housing and is coaxial with the wire hole 3. Multiple TMR magnetic field sensors 6 are arranged in a circular array on the circumferential side of the magnetic ring. The measuring axis of each TMR magnetic field sensor 6 is aligned with the axis of the magnetic ring. Specifically, the circumference of the magnetic ring has a U-shaped outer opening, and the TMR magnetic field sensors 6 are connected to the U-shaped outer opening through an insulating component. The housing also contains a miniature power supply 7 and a wireless communication module 8. The miniature power supply 7 is electrically connected to the wireless communication module 8 and each TMR magnetic field sensor 6, and the wireless communication module 8 is electrically connected to each TMR magnetic field sensor 6. When measuring cable current, the miniature power supply 7 and the wireless communication device are in the on state. The TMR magnetic field sensors transmit the measurement data to the wireless communication device, and the communication host computer receives the measurement data through an external signal relay device.

[0035] In this invention, the outer shell and the magnetic ring are symmetrically joined about the axis of the wire hole 3. Specifically, the two parts of the outer shell that are joined together are the first shell 1 and the second shell 2, and the two parts of the magnetic ring that are joined together are the first magnetic ring 4 and the second magnetic ring 5. The first magnetic ring 4 is located inside the first shell 1, and the second magnetic ring 5 is located inside the second shell 2. In this embodiment, four TMR magnetic field sensors 6 are preferred, two of which are located on the first magnetic ring 4 inside the first shell 1, and the other two are located on the second magnetic ring 5 inside the second shell 2. The axis of the wire hole 3 is located on the joining surface of the outer shell, that is, the wire hole 3 is composed of a first half-hole and a second half-hole joined together. The first half-hole is located on the first shell 1, and the second half-hole is located on the second shell 2. At least one clamping component 9 is provided inside the wire hole 3 to keep the cable under test coaxial with the magnetic ring. The clamping component 9 is also composed of two parts distributed inside the first shell 1 and the second shell 2.

[0036] By designing the outer shell and the magnetic ring into a symmetrical splicing structure about the axis of the wire hole 3, and setting the clamping component 9 in the wire hole 3 to keep the cable under test and the magnetic ring coaxial, the device can be stably installed on the cable. The clamping component 9 can not only clamp cables of different diameters, but also keep the clamped cable in a coaxial state with the magnetic ring, thus adapting to complex and diverse power distribution lines, and significantly improving the measurement accuracy.

[0037] The connection between the second shell 2 and the first shell 1 is a rotational and sliding connection. Specifically, a hinge support 10 is rotatably connected to the first shell 1. The hinge support 10 is slidably connected to the second shell 2 along a direction perpendicular to the splicing surface of the second shell 2. An elastic element 11 is provided between the second shell 2 and the hinge support 10. The elastic element 11 can be a spring rod, which is arranged along the sliding direction of the hinge support 10. One end of the spring rod is fixedly connected to the second shell 2, and the other end is fixedly connected to the hinge support 10. During the process of the second shell 2 sliding relative to the hinge support 10 to approach the first shell 1, the spring rod is compressed and stores energy. When closing the shell, the second shell 2 is first flipped so that the second shell 2 and the hinge support 10 rotate relative to the first shell 1 to an aligned state, that is, the splicing surfaces of the second shell 2 and the first shell 1 are parallel and have a gap. Then, the elastic force of the elastic element 11 is overcome and the second shell 2 is pressed to slide relative to the hinge support 10, so that the second shell 2 and the first shell 1 are joined together, and the first half hole and the second half hole are joined to form a complete wire hole 3. The second housing 2 and the first housing 1 can be locked together by a snap-fit ​​mechanism.

[0038] The clamping assembly 9 mainly includes a first wire clamp 91, a second wire clamp 99, and a centering mechanism connecting the first wire clamp 91 and the second wire clamp 99. At least one first guide rod 92 is fixedly connected inside the first housing 1. The first wire clamp 91 is slidably sleeved on the first guide rod 92 through a through hole, thereby slidably connecting the first wire clamp 91 relative to the first housing 1. One end of the first wire clamp 91, having a first wire groove, passes through the first housing 1 and enters the first half-hole. A first spring 93 is sleeved on the first guide rod 92. One end of the first spring 93 abuts against the first housing 1, and the other end abuts against the first wire clamp 91. Its elastic force acts on the first wire clamp 91 in a direction close to the axis of the first half-hole. At least one second guide rod 910 is fixedly connected inside the second housing 2. The second wire clamp 99 is slidably sleeved on the second guide rod 910 through a through hole, thereby slidably connecting the second wire clamp 99 relative to the second housing 2. One end of the second wire clamp 99, having a second wire groove, passes through the second housing 2 and enters the second half-hole. A second spring 911 is sleeved on the second guide rod 910. One end of the second spring 911 abuts against the second housing 2, and the other end abuts against the second wire clamp 99. Its elastic force acts on the second wire clamp 99 in the direction close to the axis of the second half hole.

[0039] The first wire clamp 91 and the second wire clamp 99 move synchronously in opposite directions through a centering mechanism, so that the first wire clamp 91 and the second wire clamp 99 can clamp the cable in the center relative to the wire hole 3, so as to ensure the coaxiality of the cable under test and the magnetic ring. The centering mechanism mainly includes a first connecting rod 96, a first sleeve and a first sliding column 97 provided in the first housing 1, and a second connecting rod 913, a second sliding column 914, a second sleeve 912 and an insertion rod 916 provided in the second housing 2. The end of the insertion rod 916 is provided with a ball head to reduce the friction between it and the splicing surface.

[0040] The first connecting rod 96 is slidably connected within the first housing 1 along a direction parallel to the splicing surface of the first housing 1. One end of the rod is fixedly connected to the first sleeve, and the other end is fixedly connected to the first sliding column 97. The first wire clamp 91 has a first inclined groove 98, and the first sliding column 97 is located within the first inclined groove 98 and slidably connected to the first inclined groove 98. When the first wire clamp 91 slides relative to the first housing 1, the first sleeve moves along a direction parallel to the splicing surface of the first housing 1 through the cooperation of the first inclined groove 98 and the first sliding column 97 via the first connecting rod 96. The second connecting rod 913 is slidably connected within the second housing 2 along a direction parallel to the splicing surface of the second housing 2. One end of the rod is fixedly connected to the second sleeve 912, and the other end is fixedly connected to the second sliding column 914. The second wire clamp 99 has a second inclined groove 915, and the second sliding column 914 is located within the second inclined groove 915 and slidably connected to the second inclined groove 915. The insertion rod 916 is slidably inserted into one end of the second sleeve 912. A third spring 917 is installed inside the second sleeve 912. One end of the third spring 917 abuts against the insertion rod 916, and the other end abuts against a limiting bolt at the other end of the second sleeve 912. When the spring force of the third spring 917 is released, the insertion rod 916 extends outward from the second sleeve 912. When the second wire clamp 99 slides relative to the second housing 2, the second sleeve 912 and the insertion rod 916 move in a direction parallel to the splicing surface of the second housing 2 via the cooperation of the second inclined groove 915 and the second sliding post 914 and the second connecting rod 913.

[0041] When the second housing 2 rotates relative to the first housing 1 and is about to reach the alignment state, the insertion rod 916 abuts against the splicing surface of the first housing 1, compressing the third spring 917. The insertion rod 916 retracts into the second housing 2 until the second housing 2 rotates relative to the first housing 1 and reaches the alignment state. At this point, the insertion rod 916 and the first sleeve are in a coaxial state, and the elastic force of the third spring 917 is released, allowing the insertion rod 916 to be inserted into the first sleeve. This connects the second sleeve 912 and the first sleeve through the insertion rod 916. Figure 2-7The second sleeve 912 can move synchronously with the first sleeve in a direction parallel to the splicing surface. On the other hand, it can restrict the relative rotation between the second housing 2 and the first housing 1, keeping the second housing 2 and the first housing 1 in an aligned state. During the subsequent pressing of the second housing 2 to align and splice it with the first housing 1, the first wire clamp 91 and the second wire clamp 99 elastically abut and clamp the cable under test. The first wire clamp 91 and the second wire clamp 99 will synchronously separate under the obstruction of the cable. Thus, the first wire clamp 91 slides relative to the first housing 1 and, through the first inclined groove 98 and the first sliding post 97, moves the first sleeve in a direction parallel to the splicing surface. The second wire clamp 99 slides relative to the second housing 2 and, through the second inclined groove 915 and the second sliding post 914, moves the second sleeve 912 and the insertion rod 916 in a direction parallel to the splicing surface. Because the insertion rod 916 is inserted into the first sleeve, the first sleeve and the second sleeve 912 move synchronously. Therefore, the first wire clamp 91 and the second wire clamp 99 retract into the housing to the same extent, and the cable remains centered and clamped by the first wire clamp 91 and the second wire clamp 99. The cable remains coaxial with the wire hole 3 and the magnetic ring. Figure 8-13 .

[0042] After the cable measurement is completed, an operating lever 918 is provided for easy disassembly of the device. One end of the operating lever 918 is fixedly connected to the insertion rod 916. The limiting bolt at the end of the second sleeve 912 is designed as a hollow structure. The operating end of the operating lever 918 passes through the limiting bolt and the second housing 2 in sequence and extends to the outside of the second housing 2. When disassembling the device, the operating end of the operating lever 918 is pulled away from the second housing 2 by overcoming the elastic force of the third spring 917, causing the insertion rod 916 to slide into the second sleeve 912 and exit the first sleeve. At this time, the rotational lock between the second housing 2 and the first housing 1 is released, and the second housing 2 can be rotated open relative to the first housing 1, and then removed from the cable.

[0043] For locking the second housing 2 and the first housing 1 during assembly, in addition to using a snap-fit ​​structure, this embodiment also provides a locking structure that is more stable and easier to operate. Specifically, the first sleeve includes a smooth cylindrical section 94 and a threaded sleeve section 95 coaxially fixedly connected. The threaded sleeve section 95 has internal threads, and the insertion rod 916 has external threads. When the second housing 2 and the first housing 1 are aligned, the third spring 917 causes the insertion rod 916 to insert into the smooth cylindrical section 94, as shown below. Figure 7When the second housing 2 slides and closes relative to the first housing 1 until they are joined together, the third spring 917 is further compressed and deformed. The external thread of the insert rod 916 abuts against the internal thread of the threaded sleeve section 95. Then, by rotating the operating end of the rotating operating rod 918, the insert rod 916 is rotated together, thereby enabling the insert rod 916 to be threadedly connected and engaged with the threaded sleeve section 95, until the end cap of the operating end abuts against the outer surface of the second housing 2. At this point, the second housing 2 and the first housing 1 are locked together, and they remain in a joined and engaged state. Figure 13 When it is necessary to disassemble this device, simply rotate the operating end in the opposite direction to disengage the threaded connection between the insert rod 916 and the threaded sleeve section 95 of the first sleeve, and then pull the operating end to remove the insert rod 916 from the smooth cylinder section 94 of the first sleeve, so that the second housing 2 and the first housing 1 can be opened.

[0044] It should be noted that the number of clamping components 9 is preferably two, with the two clamping components 9 distributed on both sides of the magnetic ring. This can further improve the stable clamping effect on the cable and improve the coaxiality between the cable and the magnetic ring.

[0045] The foregoing description of certain exemplary embodiments of the present invention should not be construed as limiting the scope of protection of the claims. Those skilled in the art will recognize that the described embodiments can be modified in other ways without departing from the spirit and scope of the invention.

Claims

1. A power distribution line current measurement device, comprising: The application relates to a cable detection device. The cable detection device comprises a shell and a magnetic ring, a wire hole is arranged on the shell, the magnetic ring is arranged in the shell and coaxial with the wire hole, a plurality of TMR magnetic field sensors are arranged on the circumferential side of the magnetic ring in a circumferential array, and the measuring axis of each TMR magnetic field sensor is consistent with the axis of the magnetic ring; A micro power supply and a wireless communication module are further arranged in the shell, the micro power supply is electrically connected with the wireless communication module and the TMR magnetic field sensors, and the wireless communication module is electrically connected with the TMR magnetic field sensors; The shell and the magnetic ring are a symmetrical splicing structure about the axis of the wire hole, and at least one clamping assembly is arranged in the wire hole to keep the measured cable coaxial with the magnetic ring; The two parts of the shell spliced with each other are a first shell and a second shell, a hinge support is rotatably connected to the first shell, the hinge support is slidably connected to the second shell in a direction perpendicular to the splicing surface of the second shell, and an elastic element is arranged between the second shell and the hinge support; during the sliding of the second shell relative to the hinge support to approach the first shell, the elastic element is compressed to store energy; The clamping assembly comprises a first wire clamp, a second wire clamp and a centering mechanism, the first wire clamp is slidably connected in the first shell, the second wire clamp is slidably connected in the second shell, and the first wire clamp and the second wire clamp are reversely and synchronously moved to clamp the cable in the center relative to the wire hole through the centering mechanism; The centering mechanism comprises a first sleeve, a second sleeve and a plug rod, the first sleeve is slidably connected in the first shell, the first sleeve is slidably connected with the first inclined groove on the first wire clamp through the first slide column fixedly connected with the first sleeve, the second sleeve is slidably connected in the second shell, the second sleeve is slidably connected with the second inclined groove on the second wire clamp through the second slide column fixedly connected with the second sleeve, and the plug rod is slidably connected at one end of the second sleeve; when the second shell is rotated to be aligned with the first shell, the plug rod is inserted into the first sleeve; during the sliding of the second shell to approach the first shell, the first wire clamp and the second wire clamp are elastically abutted on the measured cable and synchronously separated.

2. The distribution line current measurement apparatus according to claim 1, characterized by The circumferential side of the magnetic ring is provided with a U-shaped outer opening, and the TMR magnetic field sensor is connected into the U-shaped outer opening through an insulating element.

3. The distribution line current measurement apparatus of claim 1, wherein, At least one first guide rod is fixedly connected to the first shell, the first wire clamp is slidably sleeved on the first guide rod through a through hole on the first wire clamp, and a first spring is sleeved on the first guide rod, and the elastic force of the first spring acts on the first wire clamp in the direction close to the axis of the wire hole.

4. The distribution line current measurement apparatus of claim 1, wherein A third spring is arranged in the second sleeve, and the elastic force of the third spring makes the plug rod extend to the outside of the second sleeve.

5. The distribution line current measurement apparatus of claim 1, wherein, An operating rod is fixedly connected to the plug rod, and one end of the operating rod extends to the outside of the second shell.

6. The distribution line current measurement apparatus of claim 5, wherein, The first sleeve comprises a light cylinder segment and a screw segment connected with each other, the plug rod is provided with external threads, and after the plug rod is inserted into the light cylinder segment, the plug rod is threadedly connected with the screw segment by rotating the operating rod.

7. The distribution line current measurement apparatus of claim 1, wherein, There are two clamping assemblies, which are distributed on the two sides of the magnetic ring.

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