A current probe for non-contact cable fault detection

Abstract

The application discloses a current probe for non-contact cable fault detection, two flange connectors are arranged on a ring-shaped shielding shell, a first flange connector is used as a current injection probe, and a second flange connector is used as a current detection probe, a core wire of the first flange connector is connected with one end of a copper band, the other end of the copper band is fixed in the first half-circular ring-shaped shielding shell after being wound around a first half-circular magnetic ring and a second half-circular magnetic ring once, one end of a wrapped wire of the second flange connector is connected with a core wire, and the other end of the wrapped wire is fixed in the second half-circular ring-shaped shielding shell after being wound around a third half-circular magnetic ring and a fourth half-circular magnetic ring eight times. The original connection of the contact type cable fault detection needs to be disconnected, and the technical problem that the cable is damaged twice.

Description

Technical Field

[0001] This invention relates to the field of auxiliary tools for power equipment testing, and in particular to a current probe for non-contact cable fault detection. Background Technology

[0002] Cables have wide applications in power systems and communication technologies. During long-term operation, cables are prone to early faults such as damage from external forces, insulation aging, and moisture caused by construction, quality issues, or natural factors. These faults can seriously affect the safe and stable operation of power systems and may even cause catastrophic accidents. Therefore, it is necessary to detect and eliminate cable faults as early as possible.

[0003] Current non-destructive cable fault detection methods are mostly contact-based, requiring direct connection between the sensor and the cable conductor for signal injection and detection. This necessitates disconnecting the existing cable connection, altering the power system's interface terminals, and even offline operation of the power system, potentially leading to power outages and other unnecessary losses. Therefore, this invention provides a current probe for non-contact cable fault detection, avoiding the need to disconnect the cable's original connection and the resulting secondary damage to the cable. Summary of the Invention

[0004] This invention provides a current probe for non-contact cable fault detection, which solves the technical problem that contact cable fault detection requires disconnecting the original connection of the cable, which can cause secondary damage to the cable.

[0005] In view of this, the present invention provides a current probe for non-contact cable fault detection, comprising an annular shielding shell, a magnetic ring, a copper strip, a wrapped wire, a flange connector, a hinge, and a fixing buckle;

[0006] The annular shielding shell includes a first semi-circular annular shielding shell and a second semi-circular annular shielding shell, with the inner middle of the first and second semi-circular annular shielding shells being disconnected.

[0007] One end of the first semi-circular annular shielding shell and the second semi-circular annular shielding shell are connected by a hinge, and the other end is connected by a fixed buckle.

[0008] The magnetic ring includes a first semicircular magnetic ring, a second semicircular magnetic ring, a third semicircular magnetic ring, and a fourth semicircular magnetic ring. The first and second semicircular magnetic rings are arranged vertically within the annular cavity of the first semicircular annular shielding shell, and the third and fourth semicircular magnetic rings are arranged vertically within the annular cavity of the second semicircular annular shielding shell.

[0009] The first, second, third, and fourth semicircular magnetic rings are made of nickel-zinc ferrite material;

[0010] The flange connector includes a first flange connector for use as a current injection probe and a second flange connector for use as a current detection probe. A first mounting through hole is provided on the outer arc surface of the first semi-circular annular shielding shell, and a second mounting through hole is provided on the outer arc surface of the second semi-circular annular shielding shell. The first flange connector is mounted on the first mounting through hole, and the second flange connector is mounted on the second mounting through hole.

[0011] One end of the copper strip is fixedly connected to the core wire of the first flange connector, and the other end passes through the first mounting through hole, wraps around the first semi-circular magnetic ring and the second semi-circular magnetic ring once, and is then fixed inside the first semi-circular annular shielding shell. One end of the wrapped wire is fixedly connected to the core wire of the second flange connector, and the other end passes through the second mounting through hole, wraps around the third semi-circular magnetic ring and the fourth semi-circular magnetic ring eight times, and is then fixed inside the second semi-circular annular shielding shell.

[0012] Optionally, it also includes POE foam;

[0013] The first semicircular magnetic ring and the second semicircular magnetic ring are fixed in the annular cavity of the first semicircular annular shielding shell by POE foam pads.

[0014] The third and fourth semicircular magnetic rings are fixed within the annular cavity of the second semicircular annular shielding shell by POE foam pads.

[0015] Optionally, the inner diameter of the first, second, third, and fourth semicircular magnetic rings is 35.5 mm ± 0.1 mm, the outer diameter is 61 mm ± 0.1 mm, and the height is 20 mm ± 0.1 mm.

[0016] Optionally, the number of fasteners is two.

[0017] Optionally, one end of the copper strip is fixed to the first flange connector by welding, and the other end is fixed to the inside of the first semi-circular shielding shell by welding. One end of the wrapping wire is fixed to the second flange connector by welding, and the other end is fixed to the inside of the second semi-circular shielding shell by welding.

[0018] Optionally, the wrapping wire is a high-temperature wrapping wire.

[0019] As can be seen from the above technical solutions, the current probe for non-contact cable fault detection provided by the present invention has the following advantages:

[0020] The current probe for non-contact cable fault detection provided by this invention has two flange connectors on an annular shielded housing. The first flange connector serves as a current injection probe, and the second flange connector serves as a current detection probe. The core wire of the first flange connector is connected to one end of a copper strip, and the other end of the copper strip is wrapped around the first and second semi-circular magnetic rings once before being fixed inside the first semi-circular shielded housing. The core wire of the second flange connector is connected to one end of a wrapped wire, and the other end of the wrapped wire is wrapped around the third and fourth semi-circular magnetic rings eight times before being fixed inside the second semi-circular shielded housing. This probe is used for cable fault detection. During testing, the current probe is attached to the cable. The injection end of the current probe can be connected to a signal generator to inject a high-frequency signal into the cable. Then, the detection end of the current probe is connected to an oscilloscope or other detection receiver to detect the current in the cable. By measuring the detected current and comparing it with the injected high-frequency signal, the location of the cable fault can be determined. This method achieves non-contact cable fault detection while ensuring the sensitivity and operating frequency range of the current probe. It solves the technical problem that contact cable fault detection requires disconnecting the original cable connection and causes secondary damage to the cable.

[0021] Meanwhile, the current probe for non-contact cable fault detection provided by the present invention has an inner diameter of 35.5mm±0.1mm, an outer diameter of 61mm±0.1mm, and a height of 20mm±0.1mm for the first, second, third, and fourth semi-circular magnetic rings, so that the effective cross-sectional area of ​​the magnetic core meets the effective cross-sectional area requirements of the injection and detection probes in existing engineering. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the current probe for non-contact cable fault detection provided in this invention.

[0024] Figure 2 This is a schematic diagram of the longitudinal section of the annular shielding shell of the current probe for non-contact cable fault detection provided in this invention.

[0025] Figure 3 This is a schematic diagram of the cross-section (facing the first semi-circular shielding shell) of the current probe for non-contact cable fault detection provided in this invention.

[0026] The attached figures are labeled as follows:

[0027] 1. Cable; 2. First semi-circular shielding shell; 3. Second semi-circular shielding shell; 4. First flange connector; 5. Second flange connector; 6. Fixing buckle; 7. Copper strip; d. Spacing. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] For easier understanding, please refer to Figures 1 to 3 The present invention provides an embodiment of a current probe for non-contact cable fault detection, comprising an annular shielding shell, a magnetic ring, a copper strip, a wrapped wire, a flange connector, a hinge, and a fixing buckle;

[0030] The annular shielding shell includes a first semi-circular annular shielding shell and a second semi-circular annular shielding shell, with the inner middle of the first and second semi-circular annular shielding shells being disconnected.

[0031] One end of the first semi-circular annular shielding shell and the second semi-circular annular shielding shell are connected by a hinge, and the other end is connected by a fixed buckle.

[0032] The magnetic ring includes a first semicircular magnetic ring, a second semicircular magnetic ring, a third semicircular magnetic ring, and a fourth semicircular magnetic ring. The first and second semicircular magnetic rings are arranged vertically within the annular cavity of the first semicircular annular shielding shell, and the third and fourth semicircular magnetic rings are arranged vertically within the annular cavity of the second semicircular annular shielding shell.

[0033] The first, second, third, and fourth semicircular magnetic rings are made of nickel-zinc ferrite material;

[0034] The flange connector includes a first flange connector for use as a current injection probe and a second flange connector for use as a current detection probe. A first mounting through hole is provided on the outer arc surface of the first semi-circular annular shielding shell, and a second mounting through hole is provided on the outer arc surface of the second semi-circular annular shielding shell. The first flange connector is mounted on the first mounting through hole, and the second flange connector is mounted on the second mounting through hole.

[0035] One end of the copper strip is fixedly connected to the core wire of the first flange connector, and the other end passes through the first mounting through hole, wraps around the first semi-circular magnetic ring and the second semi-circular magnetic ring once, and is then fixed inside the first semi-circular annular shielding shell. One end of the wrapped wire is fixedly connected to the core wire of the second flange connector, and the other end passes through the second mounting through hole, wraps around the third semi-circular magnetic ring and the fourth semi-circular magnetic ring eight times, and is then fixed inside the second semi-circular annular shielding shell.

[0036] It should be noted that the first, second, third, and fourth semi-circular magnetic rings are made of nickel-zinc ferrite material, which helps to improve the operating temperature range, thus adapting to high-power operation, and also improves the performance of the current probe at high frequencies. The first and second semi-circular annular shielding shells of the current probe are connected at one end by a hinge and at the other end by a locking buckle, forming a clamp-like structure. In use, the probe is opened, and then the cable to be tested is inserted. Two locking buckles are used, which reduces cost while ensuring secure mounting.

[0037] The number of coil turns and the winding method have a significant impact on the performance of the current probe. To prevent magnetic saturation in the injected current probe, only one turn of coil is used. Simultaneously, to enable the injected current probe to handle large currents without damage, the coil wire used in the injected current probe must have a large cross-sectional area. Therefore, in this invention, the coil wire used in the injected current probe is made of copper strip. One end of the copper strip is fixedly connected to the core wire of the first flange connector, and the other end passes through the first mounting through-hole, wraps around the first and second semi-circular magnetic rings once, and is then fixed inside the first semi-circular annular shielding shell. For the current detection probe, to improve the detection sensitivity, the number of coil turns is set to 8. The coil uses wrapped wire, one end of which is fixedly connected to the core wire of the second flange connector, and the other end passes through the second mounting through-hole, wraps around the third and fourth semi-circular magnetic rings 8 times, and is then fixed inside the second semi-circular annular shielding shell. Furthermore, this invention uses an annular shielding shell with electromagnetic shielding properties. The above configuration of the injected current probe, current detection probe, and annular shielding shell helps to reduce the transfer impedance of the coil and maintain a stable transfer impedance within the operating frequency range. By integrating the current injection and detection probes into a single frame and using a nickel-zinc magnetic core with high permeability, the coupling effect of the injection probe is ensured, and the sensitivity of the probe when performing current detection is improved. In this way, the input and detection functions are combined in situations where both current injection and current detection probes are used simultaneously.

[0038] The inner middle of the first and second semi-circular annular shielding shells is broken, that is, as shown in the figure. Figure 2As shown, the inner middle of the first and second semi-circular annular shielding shells has a gap d, where d>0. The first and second semi-circular magnetic rings can be arranged vertically within the annular cavity of the first semi-circular annular shielding shell, and the third and fourth semi-circular magnetic rings can be arranged vertically within the annular cavity of the second semi-circular annular shielding shell. This eliminates the need to divide the first and second semi-circular annular shielding shells into independent first upper semi-circular annular shielding shells, first lower semi-circular shielding shells, second upper semi-circular shielding shells, and second lower semi-circular shielding shells, thus saving manufacturing process resources.

[0039] One end of the copper strip is welded to the first flange connector, and the other end is welded to the inside of the first semi-circular shielding shell. One end of the wrapped wire is welded to the second flange connector, and the other end is welded to the inside of the second semi-circular shielding shell. This welding method provides strong connection stability. The wrapped wire uses high-temperature wrapping, which offers even higher reliability.

[0040] The inner diameter of the first, second, third, and fourth semicircular magnetic rings is 35.5 mm ± 0.1 mm, the outer diameter is 61 mm ± 0.1 mm, and the height is 20 mm ± 0.1 mm. This ensures that the effective cross-sectional area of ​​the magnetic core meets the requirements of the existing engineering injection and detection probes.

[0041] The current probe in this invention also includes POE foam. The first and second semi-circular magnetic rings are fixed within the annular cavity of the first semi-circular annular shielding shell via POE foam pads, while the third and fourth semi-circular magnetic rings are fixed within the annular cavity of the second semi-circular annular shielding shell via POE foam pads. Compared to EVA foam, it is lighter and has better cold resistance, aging resistance, ozone resistance, and chemical resistance.

[0042] The current probe for non-contact cable fault detection provided by this invention has two flange connectors on an annular shielded housing. The first flange connector serves as a current injection probe, and the second flange connector serves as a current detection probe. The core wire of the first flange connector is connected to one end of a copper strip, and the other end of the copper strip is wrapped around the first and second semi-circular magnetic rings once before being fixed inside the first semi-circular shielded housing. The core wire of the second flange connector is connected to one end of a wrapped wire, and the other end of the wrapped wire is wrapped around the third and fourth semi-circular magnetic rings eight times before being fixed inside the second semi-circular shielded housing. This probe is used for cable fault detection. During testing, the current probe is attached to the cable. The injection end of the current probe can be connected to a signal generator to inject a high-frequency signal into the cable. Then, the detection end of the current probe is connected to an oscilloscope or other detection receiver to detect the current in the cable. By measuring the detected current and comparing it with the injected high-frequency signal, the location of the cable fault can be determined. This method achieves non-contact cable fault detection while ensuring the sensitivity and operating frequency range of the current probe. It solves the technical problem that contact cable fault detection requires disconnecting the original cable connection and causes secondary damage to the cable.

[0043] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A current probe for non-contact cable fault detection, characterized in that, Includes annular shielding housing, magnetic ring, copper strip, wrapped wire, flange connector, hinge, and retaining clip; The annular shielding shell includes a first semi-circular annular shielding shell and a second semi-circular annular shielding shell, with the inner middle of the first and second semi-circular annular shielding shells being disconnected. One end of the first semi-circular annular shielding shell and the second semi-circular annular shielding shell are connected by a hinge, and the other end is connected by a fixed buckle. The magnetic ring includes a first semicircular magnetic ring, a second semicircular magnetic ring, a third semicircular magnetic ring, and a fourth semicircular magnetic ring. The first and second semicircular magnetic rings are arranged vertically within the annular cavity of the first semicircular annular shielding shell, and the third and fourth semicircular magnetic rings are arranged vertically within the annular cavity of the second semicircular annular shielding shell. The first, second, third, and fourth semicircular magnetic rings are made of nickel-zinc ferrite material; The flange connector includes a first flange connector for use as a current injection probe and a second flange connector for use as a current detection probe. A first mounting through hole is provided on the outer arc surface of the first semi-circular annular shielding shell, and a second mounting through hole is provided on the outer arc surface of the second semi-circular annular shielding shell. The first flange connector is mounted on the first mounting through hole, and the second flange connector is mounted on the second mounting through hole. One end of the copper strip is fixedly connected to the core wire of the first flange connector, and the other end passes through the first mounting through hole, wraps around the first semi-circular magnetic ring and the second semi-circular magnetic ring once, and is then fixed inside the first semi-circular annular shielding shell. One end of the wrapped wire is fixedly connected to the core wire of the second flange connector, and the other end passes through the second mounting through hole, wraps around the third semi-circular magnetic ring and the fourth semi-circular magnetic ring eight times, and is then fixed inside the second semi-circular annular shielding shell.

2. The current probe for non-contact cable fault detection according to claim 1, characterized in that, Also includes POE foam; The first semicircular magnetic ring and the second semicircular magnetic ring are fixed in the annular cavity of the first semicircular annular shielding shell by POE foam pads. The third and fourth semicircular magnetic rings are fixed within the annular cavity of the second semicircular annular shielding shell by POE foam pads.

3. The current probe for non-contact cable fault detection according to claim 1, characterized in that, The inner diameter of the first, second, third, and fourth semicircular magnetic rings is 35.5 mm ± 0.1 mm, the outer diameter is 61 mm ± 0.1 mm, and the height is 20 mm ± 0.1 mm.

4. The current probe for non-contact cable fault detection according to claim 1, characterized in that, There are two fasteners.

5. The current probe for non-contact cable fault detection according to claim 1, characterized in that, One end of the copper strip is fixed to the first flange connector by welding, and the other end is fixed to the inside of the first semi-circular shielding shell by welding. One end of the wrapping wire is fixed to the second flange connector by welding, and the other end is fixed to the inside of the second semi-circular shielding shell by welding.

6. The current probe for non-contact cable fault detection according to claim 1, characterized in that, The wrapping wire is a high-temperature wrapping wire.

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