A detecting device for detecting the AC current in series in a DC control power supply of a relay protection

Abstract

The application provides a detection device for detecting AC current in a relay protection DC control power supply, which comprises a fully-closed shell, an alarm and two wire holes arranged oppositely outside the shell, a fixed layer and an AC detector arranged in the shell, a cavity in the fixed layer, a wire groove connecting the two wire holes together outside the cavity, and an AC detector embedded in the cavity of the fixed layer and isolated from the relay protection DC control power supply wires in the wire groove, and a signal output end connected with the alarm and used for collecting electromagnetic fields generated by AC current when the relay protection DC control power supply wires in the shell have AC current, processing and analyzing the collected electromagnetic fields to form an alarm signal output to the alarm for alarm. The application realizes non-contact online detection and avoids safety hazards such as DC grounding, short circuit or new parasitic loop.

Description

Technical Field

[0001] This invention relates to the field of relay protection detection technology, and in particular to a detection device for AC current being introduced into a DC control power supply for relay protection. Background Technology

[0002] Currently, the number of relay protection devices in substations and power plants is increasing with the development of the power grid, leading to a corresponding increase in the number of DC control power supplies for these devices, sometimes reaching dozens. However, the increase in AC power supplies used by external equipment (such as printer protection devices) or for the maintenance of the relay protection devices themselves, due to factors such as the close arrangement of AC / DC connection terminals or construction, often results in AC current being introduced into the DC control power supply of the relay protection devices. This reduces the sensitivity of the protection devices and threatens the safe and stable operation of the power grid.

[0003] In existing technologies, access-type online detection devices are used to monitor AC current introduced into the DC control power supply of relay protection. However, this can easily cause safety hazards such as DC grounding, short circuits, or new parasitic circuits, affecting the sensitivity of the relay protection device's protection action. Summary of the Invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide a detection device for AC current being introduced into a DC control power supply for relay protection, so as to realize non-contact online detection and avoid safety hazards such as DC grounding, short circuit or new parasitic circuit.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a detection device for AC current interfering in a relay protection DC control power supply. This device works in conjunction with the relay protection DC control power supply wires and includes a fully enclosed housing.

[0006] The outer casing is equipped with an alarm and two wire holes arranged opposite each other.

[0007] The housing contains a fixing layer and an AC detector. The fixing layer has a cavity for fixing the AC detector, and an external groove for connecting the two wire holes and allowing the relay protection DC control power supply wire to pass through. The AC detector is embedded in the cavity of the fixing layer and isolated from the relay protection DC control power supply wire passing through the wire groove. It has a signal output terminal connected to the alarm, which collects the electromagnetic field generated by the AC current when there is AC current in the relay protection DC control power supply wire, processes and analyzes the collected electromagnetic field as a voltage signal, and outputs an alarm signal to the alarm.

[0008] The AC detector also has a voltage terminal and a grounding terminal; the voltage terminal is connected to a working power supply line that extends out of the housing and is connected to an external power supply; the grounding terminal is connected to a grounding wire that extends out of the housing and is connected to the earth.

[0009] The fixing layer is made of insulating material and fills the entire shell.

[0010] The shell is composed of a shielding layer and an outer wrapping layer; wherein,

[0011] The shielding layer is made of a shielding material and is wrapped around the outer surface of the fixing layer to shield electromagnetic interference signals outside the shell.

[0012] The outer wrapping layer is made of insulating material and is wrapped around the outer surface of the shielding layer.

[0013] The housing also has a long notch for cable entry; wherein,

[0014] The elongated notch is located above the wire groove, and it passes through the outer wrapping layer and the shielding layer in sequence and is connected to the wire groove.

[0015] The shell is also provided with a sealing body; wherein,

[0016] The sealing body is slidably installed outside the housing and can slide back and forth along the outer perimeter of the housing. When it slides to the first preset position, it covers the long strip notch, and when it slides to the second preset position, it exposes the long strip notch.

[0017] The sealing body has a double-layer structure, with the layer closer to the shell made of a shielding material and the layer farther away from the shell made of an insulating material.

[0018] The alarm is a buzzer; the insulating material is silicone.

[0019] The shell is in the shape of a hollow cylinder.

[0020] Implementing the embodiments of the present invention has the following beneficial effects:

[0021] This invention uses an AC detector embedded in a cavity of a fixed layer, isolated from the DC control power supply wires for relay protection that pass through a wire groove. When AC current flows through the DC control power supply wires for relay protection, the invention collects the electromagnetic field generated by the AC current, processes and analyzes the collected electromagnetic field as a voltage signal, and outputs an alarm signal to the alarm device. This achieves non-contact online detection and avoids safety hazards such as DC grounding, short circuits, or new parasitic circuits. 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, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0023] Figure 1 This is a front sectional view of a detection device for AC current being inserted into a DC control power supply for relay protection, provided in an embodiment of the present invention.

[0024] Figure 2 This is a side view of a detection device for AC current being inserted into a DC control power supply for relay protection, provided in an embodiment of the present invention.

[0025] Figure 3 This is a bottom view of a detection device for AC current being introduced into a DC control power supply for relay protection, provided in an embodiment of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0027] like Figures 1 to 3 As shown in the figure, this is a detection device for AC current being inserted into a DC control power supply for relay protection, proposed in an embodiment of the present invention. It cooperates with the DC control power supply conductor T for relay protection and includes a fully enclosed, hollow cylindrical (or other structured) housing 1; wherein,

[0028] The housing 1 is equipped with an alarm (such as a buzzer or indicator light) 11 and two wire holes 12 arranged opposite each other; these two wire holes 12 are hollow holes to allow the relay protection DC control power supply wire T to pass through;

[0029] The housing 1 contains a fixing layer 13 and an AC detector 14. The fixing layer is made of insulating material and fills the entire housing. It has a cavity for fixing the AC detector 14 and an external wire groove 15 for connecting two wire holes 12 and for the relay protection DC control power supply wire T to pass through. The AC detector 14 is embedded in the cavity of the fixing layer 13 and is isolated from the relay protection DC control power supply wire T passing through the wire groove 15. It has a signal output terminal (not shown) connected to the alarm 11. When there is AC current in the relay protection DC control power supply wire T, it collects the electromagnetic field generated by the AC current and processes and analyzes the collected electromagnetic field to form an alarm signal output to the alarm 11 for alarm.

[0030] It should be noted that electromagnetic field voltage signal processing and analysis includes converting the strength of the electromagnetic field into a voltage signal of corresponding level, as well as the circuit oscillation, detection, amplification and shaping of the voltage signal before output.

[0031] It is understood that the AC current detector 14 can be equipped with a built-in rechargeable battery to provide the operating voltage, or it can be equipped with an external power supply. In this case, the AC current detector 14 also has a voltage terminal (not shown), which is connected to a power supply line 141 that extends out of the housing 1 and is connected to the external power supply. Of course, for grounding protection, the AC current detector 14 also has a grounding terminal (not shown), which is connected to a grounding wire 142 that extends out of the housing 1 and is connected to the earth.

[0032] In this embodiment of the invention, in order to shield the electromagnetic interference signals outside the housing 1 from the influence of the detection results and to ensure operational safety, the housing 1 adopts a double-layer structure consisting of a shielding layer 16 and an outer wrapping layer 17. The shielding layer 16 is made of a shielding material (which can be designed according to the actual environment) and is wrapped around the outer surface of the fixing layer 13 to shield the electromagnetic interference signals outside the housing 1. The outer wrapping layer 17 is made of an insulating material (such as silicone) and is wrapped around the outer surface of the shielding layer 16.

[0033] In this embodiment of the invention, in order to facilitate the installation and disassembly of the DC control power supply wire T for relay protection, the housing 1 is designed with a certain structure, such as a long strip notch 18 for the wire inlet on the housing 1; the long strip notch 18 is located above the wire groove 15, and it passes through the outer wrapping layer 17 and the shielding layer 16 in sequence and is connected to the wire groove 15, so that the long strip notch 18 and the wire groove 15 are connected to form an outward-opening groove.

[0034] Of course, considering the groove formed by the long notch 18 and the wire groove 15 connecting the DC control power supply wire T of the relay protection, electromagnetic interference signals outside the housing 1 may affect the detection results. Therefore, a sealing body 19 is provided on the housing 1 to prevent this. At this time, the sealing body 19 is slidably installed outside the housing 1 and can slide back and forth along the outer perimeter of the housing 1 (e.g., Figure 1 and 2 As indicated by the middle arrow, the sealing body 19 covers the elongated notch 18 when it slides to the first preset position, and exposes the elongated notch 18 when it slides to the second preset position. The sealing body 19 adopts a double-layer structure. The layer near the shell 1 is made of a shielding material (which can be the same material as the shielding layer 16), and the layer away from the shell 1 is made of an insulating material (such as silicone). Therefore, when the sealing body 19 is closed, it achieves a complete shielding ring, shielding external electromagnetic interference signals and preventing interference with the test results.

[0035] Implementing the embodiments of the present invention has the following beneficial effects:

[0036] This invention uses an AC detector embedded in a cavity of a fixed layer, isolated from the DC control power supply wires for relay protection that pass through a wire groove. When AC current flows through the DC control power supply wires for relay protection, the invention collects the electromagnetic field generated by the AC current, processes and analyzes the collected electromagnetic field as a voltage signal, and outputs an alarm signal to the alarm device. This achieves non-contact online detection and avoids safety hazards such as DC grounding, short circuits, or new parasitic circuits.

[0037] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A detection device for AC current being inserted into a DC control power supply for relay protection, which is used in conjunction with the conductors of the DC control power supply for relay protection, characterized in that, Including a fully enclosed shell; among which, The outer casing is equipped with an alarm and two wire holes arranged opposite each other. The housing contains a fixing layer and an AC detector. The fixing layer has a cavity for fixing the AC detector, and an external groove for connecting the two wire holes and allowing the relay protection DC control power supply wire to pass through. The AC detector is embedded in the cavity of the fixing layer and isolated from the relay protection DC control power supply wire passing through the wire groove. It has a signal output terminal connected to the alarm, which collects the electromagnetic field generated by the AC current when there is AC current in the relay protection DC control power supply wire, processes and analyzes the collected electromagnetic field as a voltage signal, and outputs an alarm signal to the alarm. The AC detector also has a voltage terminal and a grounding terminal; wherein, the voltage terminal is connected to a working power supply line that extends out of the housing and is connected to an external power supply; the grounding terminal is connected to a grounding wire that extends out of the housing and is connected to the earth. The fixing layer is made of insulating material and fills the entire shell; the shell consists of a shielding layer and an outer wrapping layer; wherein, the shielding layer is made of a material with shielding function and is wrapped around the outer surface of the fixing layer to shield electromagnetic interference signals outside the shell; the outer wrapping layer is made of insulating material and is wrapped around the outer surface of the shielding layer.

2. The detection device for AC current being inserted into the DC control power supply of relay protection as described in claim 1, characterized in that, The housing is also provided with a long notch for cable entry; wherein... The elongated notch is located above the wire groove, and it passes through the outer wrapping layer and the shielding layer in sequence and is connected to the wire groove.

3. The detection device for AC current interfering in a DC control power supply for relay protection as described in claim 2, characterized in that, The shell is also provided with a sealing element; wherein... The sealing body is slidably installed outside the housing and can slide back and forth along the outer perimeter of the housing. When it slides to the first preset position, it covers the long strip notch, and when it slides to the second preset position, it exposes the long strip notch.

4. The detection device for AC current being inserted into the DC control power supply for relay protection as described in claim 3, characterized in that, The sealing body adopts a double-layer structure, with the layer closer to the shell made of a shielding material and the layer farther away from the shell made of an insulating material.

5. The detection device for AC current being inserted into the DC control power supply for relay protection as described in claim 4, characterized in that, The alarm is a buzzer; the insulating material is silicone.

6. The detection device for AC current being inserted into the DC control power supply for relay protection as described in claim 5, characterized in that, The shell is in the shape of a hollow cylinder.

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