Line bushing type voltage and current sensor

Abstract

The utility model provides a kind of outlet bushing type voltage current sensor, including current sensor coil, voltage sensor, bushing body and conducting rod, conducting rod is arranged in bushing body, current sensor coil is sleeved in the outside of conducting rod, output end is located bushing body surface;Voltage sensor includes the support of tower type spiral structure and multiple capacitors arranged at intervals, support one end is equipped with with the primary installation end being connected with conducting rod, the other end is equipped with the secondary outlet terminal being located bushing body surface.The utility model solves the technical problem that voltage current integration sensor is difficult to realize electric field uniformity and insulation cooperation under the condition that ring main unit outlet bushing inner space is limited.

Description

Technical Field

[0001] This utility model relates to the field of power online monitoring equipment technology, specifically to an outgoing bushing type voltage and current sensor. Background Technology

[0002] As a critical switching device in power distribution networks, ring main units typically require the insulation crossing of conductive rods and the acquisition and measurement of voltage and current signals within a limited space at their outgoing terminals. Traditional current and voltage measurements often rely on independent instrument transformers or external sensing components, which are not only bulky and have complex wiring, but also fail to meet the insulation requirements of the compact internal space of the ring main unit, as well as creepage distances and electrical clearances.

[0003] In existing technologies, voltage measurement often employs capacitive or resistive voltage division. However, these structures are susceptible to electromagnetic interference in high-voltage miniaturization environments, exhibiting limited stability of the voltage division ratio and anti-interference capabilities, as well as weak output drive capability. While Rogowski coils can achieve non-contact current detection, they require active secondary processing circuitry, resulting in complex power supply and signal transmission, which is not conducive to integrated design within the bushing.

[0004] To improve system integration and reliability, the industry trend is to integrate voltage and current sensors into the bushing of a ring main unit. By arranging a current sensing coil inside the bushing and surrounding it with a capacitive voltage sensing unit, electrical parameter measurements can be performed without occupying additional external space. Voltage sensors typically employ a capacitive voltage divider structure, with multiple capacitors forming a voltage divider network on a support, where the high-voltage arm is connected in series and the low-voltage arm in parallel. To address space constraints and uneven electric field, a spiral or conical spiral support structure can be used, with capacitor elements arranged at reasonable intervals. The primary lead is positioned near the conductive rod, and the secondary lead is positioned near the bushing surface to optimize the electric field distribution, reduce the risk of partial discharge, and suppress signal crosstalk. This achieves a compact overall design with integrated sensor, reliable insulation, and a robust structure.

[0005] For example, Chinese patent CN208156079U discloses an electronic metering sensor for ring main units. This sensor includes a ring current sensor and a capacitive voltage sensor, achieving voltage division sampling through a thin-film capacitor. It is combined with a ring current transformer to form a cable accessory, solving the shortcomings of traditional CTs (current transformers) in terms of accuracy and stability. Simultaneously, the 10kV voltage division technology ensures the system's operational stability. However, this solution still has room for improvement in terms of space utilization, sensor unit layout, electric field uniformity, and integration level. Utility Model Content

[0006] In view of the deficiencies in the existing technology, the purpose of this utility model is to provide a bushing-type voltage and current sensor.

[0007] According to the present invention, a bushing-type voltage and current sensor includes a current sensor coil, a voltage sensor, a bushing body, and a conductive rod. The conductive rod is inserted into the bushing body, and the current sensor coil is sleeved outside the conductive rod. The output end of the current sensor coil is located on the surface of the bushing body. The voltage sensor includes a bracket and multiple capacitors. The bracket has a spiral structure, and the multiple capacitors are arranged at intervals on the bracket. One end of the bracket is provided with a primary mounting end connected to the conductive rod, and the other end of the bracket is provided with a secondary output terminal located on the surface of the bushing body.

[0008] Preferably, the bracket has a conical spiral structure, with the primary installation end connected to the end with a smaller diameter and the secondary output terminal connected to the end with a larger diameter.

[0009] Preferably, the primary installation end is a first connecting line, which is arranged radially inward, and the secondary output terminal is a second connector, with the bracket end connected to the second connector via the second connecting line and the connecting plate.

[0010] Preferably, the output terminal of the current sensor coil is a first connector.

[0011] Preferably, the bracket is made of insulating material, and the surface of the bracket is covered with copper foil. The capacitor, the first connecting wire, and the second connecting wire are fixedly connected to the copper foil by soldering.

[0012] Preferably, the first connecting wire is fixedly connected to the conductive rod and the bracket by soldering.

[0013] Preferably, the second connecting wire is fixedly connected to the bracket and the second connecting plate by soldering.

[0014] Preferably, the second connector is fixedly connected to the second connecting plate by soldering.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The voltage sensor employs a conical spiral structure. The primary mounting end of the bracket faces and connects to the conductive rod. The secondary output terminal reliably connects to the secondary connector via a second connecting plate on the bushing body surface. The geometric taper creates a natural interface transition between the primary and secondary ends in the axial and radial directions, shortening the primary high-voltage connection path, reducing electric field distortion, and reserving stable creepage distances and electrical clearances for the secondary leads and terminations. Multiple capacitors are spaced along the conical spiral bracket, balancing the electric field distribution circumferentially and axially, reducing local peaks and parasitic parameter unevenness. Simultaneously, the conical spiral provides layered space for capacitors and leads, optimizing conductor routing and shielding layout, and reducing signal crosstalk. This structure facilitates the integration of the voltage sensor entirely within the bushing body, achieving zoned integration of primary and secondary functional ends. This reduces installation footprint, improves overall structural compactness and assembly consistency, while also ensuring withstand voltage performance, anti-interference capability, and ease of maintenance. Attached Figure Description

[0016] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the internal structure of the voltage and current sensor in this embodiment; Figure 2 This is an external schematic diagram of the voltage and current sensor in this embodiment; Figure 3 A schematic diagram of a voltage sensor at one angle; Figure 4 This is a schematic diagram of a voltage sensor from another angle.

[0017] In the figure, 1. Sleeve body, 2. Conductive rod, 3. Current sensor coil, 4. Voltage sensor, 5. First connector, 6. Second connector, 7. Bracket, 8. Capacitor, 9. First connecting line, 10. Second connecting line, 11. Second connecting plate. Detailed Implementation

[0018] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0019] This application provides a bushing-type voltage and current sensor for detecting the electrical parameters of the primary conductor rod at the outgoing end of high-voltage power distribution equipment such as ring main units. This sensor integrates a voltage sensor and a current sensor into the internal structure of the bushing, enabling simultaneous acquisition of primary voltage and current signals within a limited space, thus improving the compactness and reliability of the device. Figure 1 , Figure 2 As shown, it includes a bushing body 1, a conductive rod 2, a current sensor coil 3, and a voltage sensor 4. The conductive rod 2 passes axially inside the bushing body 1, serving as a primary conductor path. The current sensor coil 3 is sleeved on the outside of the conductive rod 2, used to sense changes in the magnetic field of the primary current and output the corresponding secondary signal. The output end of the current sensor coil 3 is located on the surface of the bushing body 1, and a standardized interface output is achieved through a first connector 5, facilitating signal acquisition and maintenance.

[0020] A voltage sensor 4 is installed between the conductive rod 2 and the bushing body 1. Its structure includes a bracket 7 and multiple capacitor elements 8. The bracket 7 adopts a spiral or preferably conical spiral structure, with several capacitor units 8 spaced apart along the spiral path on the outer surface of the bracket 7. Electrically, each capacitor 8 forms a voltage divider network with the high-voltage arm connected in series and the low-voltage arm connected in parallel, used to achieve capacitor-based voltage division measurement of the high-voltage signal. One end of the bracket 7 has a primary mounting terminal electrically connected to the conductive rod 2, and the other end has a secondary output terminal located on the surface of the bushing body 1, used to lead out the voltage sensing signal.

[0021] In the preferred structure, the diameter of the bracket 7 gradually increases from the inside out, forming a conical spiral shape. The primary mounting end is located at the smaller diameter end and is connected to the conductive rod 2 via the first connecting line 9. The secondary output terminal is located at the larger diameter end and is connected to the second aviation plug 6 via the second connecting line 10 and the second connecting plate 11. The aviation plug is mounted on the sleeve surface as a secondary signal interface. The bracket 7 is made of insulating material, and its surface is covered with copper foil, which serves as the welding conductor layer for the capacitor 8 and the connecting lines. The capacitor 8, the first connecting line 9, and the second connecting line 10 are all fixed to the copper foil surface by soldering to ensure conductivity stability and mechanical strength. The first connecting line 9 is fixedly connected to the conductive rod 2 and the bracket 7 by soldering, achieving reliable electrical contact on the high-voltage side. The second connecting line 10 is firmly fixed to the bracket 7 and the second connecting plate 11 by soldering, and the second aviation plug 6 is installed on the second connecting plate 11 by soldering, forming a complete secondary output path.

[0022] During operation, the conductive rod 2 conducts the primary current, and the current sensor coil 3 in the outer sleeve senses the change in its magnetic field, converting the primary current signal into a proportional output secondary signal. Simultaneously, the voltage divider network of capacitor 8 in the voltage sensor 4 establishes a uniform electric field between the high potential of the conductive rod 2 and the low potential outside the sleeve, achieving stable voltage division of the high-voltage signal. The geometric structure of the spiral or conical spiral support 7 improves the electric field distribution, reduces the risk of partial discharge, and suppresses electromagnetic crosstalk between capacitors 8, thereby achieving structural integration and optimized insulation for high-precision voltage and current measurement.

[0023] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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. Therefore, they should not be construed as limitations on this application.

[0024] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the substantive content of this utility model. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A bushing-type voltage and current sensor, characterized in that, The device includes a current sensor coil (3), a voltage sensor (4), a bushing body (1), and a conductive rod (2). The conductive rod (2) is inserted into the bushing body (1). The current sensor coil (3) is sleeved outside the conductive rod (2). The output end of the current sensor coil is located on the surface of the bushing body (1). The voltage sensor (4) includes a bracket (7) and multiple capacitors (8). The bracket (7) has a spiral structure. The multiple capacitors (8) are arranged at intervals on the bracket (7). One end of the bracket (7) is provided with a primary mounting end connected to the conductive rod (2). The other end of the bracket is provided with a secondary output terminal. The secondary output terminal is located on the surface of the bushing body (1).

2. The bushing-type voltage and current sensor according to claim 1, characterized in that, The bracket (7) has a conical spiral structure. The primary installation end is connected to the end of the bracket (7) with a smaller diameter, and the secondary output terminal is connected to the end of the bracket (7) with a larger diameter.

3. The bushing-type voltage and current sensor according to claim 1 or 2, characterized in that, The primary installation end is the first connecting line (9), which is arranged radially inward. The secondary output terminal is the second navigation plug (6), and the end of the bracket (7) is connected to the second navigation plug (6) through the second connecting line (10) and the connecting plate (11).

4. The bushing-type voltage and current sensor according to claim 1, characterized in that, The output terminal of the current sensor coil (3) is the first connector (5).

5. The bushing-type voltage and current sensor according to claim 3, characterized in that, The bracket (7) is made of insulating material, and the surface of the bracket is covered with copper foil. The capacitor, the first connecting line, and the second connecting line are fixedly connected to the copper foil by soldering.

6. The bushing-type voltage and current sensor according to claim 3, characterized in that, The first connecting line (9) is fixedly connected (10) to the conductive rod (2) and the bracket (7) by soldering.

7. The bushing-type voltage and current sensor according to claim 3, characterized in that, The second connecting line (10) is fixedly connected to the bracket (7) and the second connecting plate (11) by soldering.

8. The bushing-type voltage and current sensor according to claim 3, characterized in that, The second connector (6) is fixedly connected to the second connector plate (11) by soldering.

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