Integrated sleeve type electronic current and voltage combined transformer with temperature monitoring function

Abstract

The utility model relates to the technical field of power equipment, in particular to an integrated sleeve type electronic current and voltage combined transformer with a temperature monitoring function. Comprising a secondary signal transmission assembly, an insulating shell, and a conducting rod, a temperature monitoring module, a current measuring module, a voltage measuring module and a capacitance monitoring module which are arranged in the insulating shell, a boss is arranged at the side part of the insulating shell, and the conducting rod penetrates through the center of the insulating shell; the capacitance monitoring module comprises a capacitance wiring terminal and a capacitance induction net coaxially arranged with the conducting rod, and the current measuring module comprises a Rogowski coil arranged on the outer side of the capacitance induction net in a sleeving mode; the voltage measuring module comprises a primary ceramic capacitor fixed on the outer side of the conducting rod and a secondary capacitor connected in series with the primary ceramic capacitor; the secondary signal transmission assembly is embedded in the boss, and the Rogowski coil, the secondary capacitor and the temperature monitoring module are all connected with the secondary signal transmission assembly. The system provided by the utility model has the advantages of high integration level, strong adaptability, excellent safety, reliable performance, controllable cost and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of electric power equipment, especially to integrated bushing type electronic current voltage combination mutual inductor with temperature monitoring. BACKGROUND

[0002] As the core power distribution equipment of modern urban distribution network, industrial park, commercial center, large building, infrastructure (such as airport, station, hospital), residential area and renewable energy station (such as wind power station, photovoltaic power station) booster station, etc., ring network cabinet is widely used due to its high reliability, compact structure, high degree of modularization and other advantages.

[0003] However, the ring network cabinet generally adopts a compact design of full insulation and full sealing, and the internal space is extremely limited. With the continuous improvement of the automation level of the distribution network, more and more secondary devices need to be integrated in the ring network cabinet to realize state monitoring, protection and control functions. Among them, the high-precision, wide-band measurement of the primary loop current and voltage signal and the monitoring of the internal key state of the equipment (such as temperature, insulation) are increasingly prominent.

[0004] The current implementation of the above signal acquisition and state monitoring in the ring network cabinet mainly faces the following technical problems:

[0005] Installation space is severely limited: the compact full insulation and sealing structure of the ring network cabinet makes it extremely difficult or even impossible to install traditional electromagnetic current transformers (CT), electromagnetic voltage transformers (PT) or their combination devices in the cabinet. Even the relatively small electronic mutual inductor (such as independent Rogowski coil ECT plus capacitor voltage divider EVT), independent installation of multiple devices in a small space also has the problem of physical interference and insufficient space.

[0006] High transformation cost: to meet the automation transformation needs, independent CT, PT and other mutual inductor devices usually need to be additionally installed in the limited cabinet space. This not only increases the purchase cost of the devices, but also leads to high construction difficulty, long cycle and high cost in the complex installation process (especially for the transformation of the already operating ring network cabinet), which greatly restricts the promotion of automation transformation.

[0007] Single function and low integration: traditional mutual inductor usually only has a single current or voltage measurement function. If current, voltage measurement and temperature, insulation state monitoring functions are needed, multiple different types of sensors need to be installed, further aggravating the space occupation and cost problem, and independent installation of each sensor makes it difficult to ensure the compactness and reliability of the overall structure.

[0008] Therefore, there is an urgent need to develop a new type of instrument transformer solution that is highly compact in structure, highly integrated in function, can directly replace the original standard installation components (such as bushings) in the ring main unit, and can simultaneously meet the needs of current and voltage measurement, internal temperature monitoring and insulation status monitoring, so as to overcome the bottleneck problems of installation difficulties, high costs and single functions faced by existing technologies in the automation transformation of ring main units. Utility Model Content

[0009] To address the aforementioned problems, the purpose of this utility model is to provide an integrated bushing-type electronic current and voltage combined transformer with temperature monitoring, in order to solve the problems of traditional transformers being difficult to install, costly, and having limited functionality, making it difficult to meet the comprehensive monitoring needs of current, voltage, temperature, and insulation status in automation upgrades.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] This utility model provides an integrated bushing-type electronic current and voltage combined transformer with temperature monitoring, including a secondary signal transmission component, an insulating shell, and a conductive rod, a temperature monitoring module, a current measurement module, a voltage measurement module, and a capacitance monitoring module disposed inside the insulating shell. The insulating shell has a boss on its side, and the conductive rod passes through the center of the insulating shell.

[0012] The capacitance monitoring module includes capacitance terminals and a cylindrical capacitance sensing mesh. The capacitance sensing mesh is arranged coaxially with the conductive rod. The capacitance terminals are embedded in the boss and connected to the capacitance sensing mesh.

[0013] The current measurement module includes a Rogowski coil fitted around the outside of the capacitive sensing grid;

[0014] The voltage measurement module includes a primary ceramic capacitor fixed to the outside of the conductive rod and a secondary capacitor connected in series with the primary ceramic capacitor.

[0015] The secondary signal transmission component is embedded on the boss, and the Rogowski coil, secondary capacitor and temperature monitoring module are all connected to the secondary signal transmission component.

[0016] The secondary signal transmission component includes a female connector, a connector, a male connector, and a multi-core shielded twisted pair cable. The female connector is embedded in the boss and gathers the output signal lines of the Rogowski coil, the secondary capacitor, and the temperature monitoring module. The two ends of the multi-core shielded twisted pair cable are connected to the male connector and the female connector, respectively. The male connector mates with the female connector, and the connector is used to output signals to external devices.

[0017] The metal housing of the connector female is electrically connected to the grounding terminal via a shielded wire, and the grounding terminal is located on the boss.

[0018] The shielding layer of the multi-core shielded twisted pair cable, the outer shell of the male connector, and the outer shell of the female connector are electrically connected to form a grounding anti-interference circuit.

[0019] The temperature monitoring module includes a resistance temperature sensor embedded in the insulating housing. The resistance temperature sensor is located outside the capacitive sensing network shown, and the signal line of the resistance temperature sensor is connected to the connector socket.

[0020] The Rogowski coil includes a non-magnetic coil frame and coil wires wound around the coil frame. The two ends of the coil wires are connected to the connector socket. The Rogowski coil outputs a voltage signal that is proportional to the derivative of the measured current.

[0021] The insulating shell is a tubular structure cast from epoxy resin. The front and rear ends of the insulating shell are conical and cylindrical, respectively. A flange plate is provided in the middle of the insulating shell, and the flange plate extends radially to form the boss.

[0022] The mounting surface of the flange plate is provided with a sealing groove.

[0023] The secondary capacitor is disposed inside the boss.

[0024] The advantages and beneficial effects of this utility model are as follows: The integrated bushing-type electronic current and voltage combined transformer with temperature monitoring provided by this utility model has the advantages of high integration, strong adaptability, excellent safety, reliable performance, and controllable cost. It innovatively integrates four functions: coil current measurement, capacitive voltage division measurement, embedded thermal resistor temperature monitoring, and capacitive induction network insulation monitoring, without the need for additional equipment. It adopts a standard bushing shape and can directly replace the original bushing of the ring main unit without modifying the cabinet to fit the compact space. It forms a dual safety guarantee through temperature early warning and insulation monitoring, and ensures data reliability by relying on anti-interference technology and high-precision measurement principles. At the same time, the fully sealed maintenance-free design reduces operation and maintenance costs, saves the cost of purchasing independent equipment and expanding the cabinet, reduces the transformation cost of typical scenarios, and comprehensively solves the problem of automated transformation of ring main units.

[0025] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0026] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0027] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0028] Figure 1 This is a schematic diagram of the structure of the integrated bushing-type electronic current and voltage combined transformer with temperature monitoring according to this utility model.

[0029] Figure 2 This is a front view of the integrated bushing-type electronic current and voltage combined transformer with temperature monitoring according to this utility model.

[0030] Figure 3 for Figure 2 The left view;

[0031] Figure 4 This is a circuit diagram of the current measurement module in this utility model;

[0032] Figure 5 This is a circuit diagram of the voltage measurement module in this utility model.

[0033] The components include: 1. Insulating shell; 4. Sealing groove; 5. Conductive rod; 6. Resistance temperature sensor; 7. Rogowski coil; 8. Coil frame; 9. Coil wire; 10. Capacitive sensing mesh; 11. Primary ceramic capacitor; 12. Secondary capacitor; 13. Connector female; 14. Connector male; 15. Multi-core shielded twisted pair cable; 16. Connector; 17. Capacitor terminal; 18. Grounding terminal; 19. Shielded wire; 101. Cone; 102. Flange plate; 103. Cylindrical-like shape. Detailed Implementation

[0034] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0035] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0036] See Figures 1 to 5As shown, this utility model provides an integrated bushing-type electronic current and voltage combined transformer with temperature monitoring, including a secondary signal transmission component, an insulating shell 1, and a conductive rod 5, a temperature monitoring module, a current measurement module, a voltage measurement module, and a capacitance monitoring module disposed within the insulating shell 1. The insulating shell 1 has a boss on its side, and the conductive rod 5 penetrates the center of the insulating shell 1. The capacitance monitoring module includes a capacitor terminal 17 and a cylindrical capacitor sensing network 10, with the capacitor sensing network 10 arranged coaxially with the conductive rod 5. The capacitor terminal 17 is embedded in the boss and connected to the capacitor sensing network 10. The current measurement module includes a Rogowski coil 7 sleeved on the outside of the capacitor sensing network 10. The voltage measurement module includes a primary ceramic capacitor 11 fixed to the outside of the conductive rod 5 and a secondary capacitor 12 connected in series with the primary ceramic capacitor 11. The secondary signal transmission component is embedded in the boss, and the Rogowski coil 7, the secondary capacitor 12, and the temperature monitoring module are all connected to the secondary signal transmission component.

[0037] See Figures 1 to 3 As shown in the embodiment of this utility model, the secondary signal transmission component includes a female connector 13, a male connector 14, a multi-core shielded twisted pair cable 15, and a connector 16. The female connector 13 is embedded in the boss and collects the output signal lines of the Rogowski coil 7, the secondary capacitor 12, and the temperature monitoring module. The two ends of the multi-core shielded twisted pair cable 15 are connected to the male connector 14 and the connector 16, respectively. The male connector 14 mates with the female connector 13, and the connector 16 is used to output signals to external devices. Specifically, the connector 16 is an RJ45 connector.

[0038] Specifically, the multi-core shielded twisted pair cable 15 adopts a structure of multiple sets of twisted wire cores + metal shielding layer, and is connected to connector 16 at the end. It is used to output all secondary signals (current, voltage, and temperature monitoring values) collected by connector female 13 to an external intelligent electronic device (IED). Each of the three secondary signals (current, voltage, and temperature monitoring values) uses one set of shielded twisted pair cable for transmission. The shielding layer of the multi-core shielded twisted pair cable 15, the outer shell of connector male 14, and the outer shell of connector female 13 are electrically connected. The metal shell of connector female 13 is electrically connected to grounding terminal 18 through shielding wire 19. Grounding terminal 18 is located on a boss, forming a complete grounding anti-interference loop. See [link to documentation]. Figure 4 and Figure 5 As shown.

[0039] See Figure 1As shown in the embodiment of this utility model, the temperature monitoring module includes a resistance temperature sensor 6 embedded in an insulating shell 1. The resistance temperature sensor 6 is located outside the capacitive sensing network 10. The resistance temperature sensor 6 is electrically insulated by being wrapped in the insulating shell 1. The signal line of the resistance temperature sensor 6 is connected to the connector socket 13. The resistance temperature sensor 6 senses the internal temperature in real time, ensuring that it can accurately reflect the temperature of the core area inside the transformer.

[0040] Specifically, the capacitive sensing mesh 10 is a cylindrical metal mesh, coaxially arranged outside the conductive rod 5, forming a parallel-plate capacitor with epoxy resin filling the space between the plates. The capacitive sensing mesh 10 and the conductive rod 5 together constitute a monitoring capacitor, used to sense and output a capacitance value reflecting the state of the insulating medium. The capacitance signal is connected via leads to the capacitor terminal 17 for external measurement.

[0041] Furthermore, the capacitive sensing network 10 is fixed by a support structure to ensure the coaxiality and distance stability between it and the conductive rod 5, thereby ensuring the accuracy of the monitored capacitance value.

[0042] See Figure 4 As shown in the embodiment of this utility model, the Rogowski coil 7 includes a non-magnetic coil frame 8 and a coil conductor 9. The coil conductor 9 is insulated enameled wire, uniformly wound on the non-magnetic annular coil frame 8 to form a coreless Rogowski coil 7. It is then coaxially fitted onto the outside of the conductive rod 5 to sense changes in the primary current. Both ends of the coil conductor 9 are connected to connector female sockets 13. The output terminal of the Rogowski coil 7 generates a voltage signal proportional to the derivative of the measured current, possessing advantages such as wide dynamic range, high linearity, no magnetic saturation, and no hysteresis. The voltage signal is converted back to the primary current value by an external integrating circuit; this transformer does not contain an integrator.

[0043] Specifically, a Rogowski coil, also known as a hollow coil, is a toroidal coil uniformly wound on a non-ferromagnetic material. It is a current transformer with a single-turn primary winding and a multi-turn secondary winding. Its function is to convert a high-voltage, high-current signal on the primary bus into a low-voltage, low-current signal on the secondary side. The measured primary current can then be obtained by integrating the coil's output signal using microelectronics. Rogowski coils possess inherent advantages such as no magnetic saturation, wide dynamic range, high linearity, and wide frequency response, making them particularly suitable for current measurement under complex operating conditions, offering high measurement accuracy and reliability.

[0044] Specifically, the conductive rod 5 is a rod-shaped metal conductor that runs through the central axis of the current transformer. Both ends of the conductive rod 5 have threaded holes or other forms of fixing devices. The two ends of the conductive rod 5 serve as the inflow and outflow terminals of the current transformer, namely terminals P1 and P2, respectively. The high-voltage end of the primary ceramic capacitor 11 is fixedly connected to the outer wall of the conductive rod 5, forming the high-voltage arm of the capacitor voltage divider circuit. The secondary capacitor 12 is connected in series with the primary ceramic capacitor 11, forming the low-voltage arm of the capacitor voltage divider circuit, outputting the divided secondary voltage signal to the connector socket 13.

[0045] In this embodiment of the invention, the insulating shell 1 is a tubular fully sealed structure formed by epoxy resin casting and curing. The tubular fully sealed structure encapsulates and fixes the conductive rod 5, temperature monitoring module, current measurement module, voltage measurement module, capacitance monitoring module, and connector socket 13, forming a fully sealed, maintenance-free integrated structure. During the curing process, reliable insulation between electrical components and between components and the shell is ensured.

[0046] Furthermore, the front and rear ends of the insulating shell 1 are a cone 101 and a near-cylinder 103, respectively. A flange plate 102 is provided in the middle of the insulating shell 1, and a boss extends radially from one side of the flange plate 102. The secondary capacitor 12 is disposed inside the boss. See [reference needed]. Figure 1 and Figure 2 As shown. The cone 101 is a standard-sized outer cone that can be connected to a standard equipment cone sleeve. The near-cylinder 103 is a regular, approximately cylindrical shape, facilitating installation through openings in the switchgear.

[0047] Furthermore, the mounting surface of the flange plate 102 is provided with a sealing groove 4 along the circumference, and a sealing ring is embedded in the sealing groove 4, so that the flange plate 102 can be fixed and sealed with the equipment panel.

[0048] In this embodiment of the invention, the connector female socket 13 is a multi-core connector, fixedly installed and embedded inside epoxy resin. The main body of the connector female socket 13 (including all internal terminals) is integrally cured and encapsulated with the epoxy resin during the current transformer casting process, ensuring the sealing and reliability of the internal electrical connections. Only the mating socket is exposed on the cured epoxy resin surface. The terminals inside the epoxy resin of the connector female socket 13 are electrically connected to the output signal lines of the current measurement module, voltage measurement module, and temperature monitoring module, respectively, realizing the internal aggregation of all measurement signals. The metal shell of the connector female socket 13 is electrically connected to the grounding terminal 18 to achieve reliable grounding of the multi-core shielded twisted pair cable 15, enhancing anti-interference capabilities.

[0049] See Figure 5 As shown in the embodiment of this utility model, the voltage measurement module is based on the principle of capacitive voltage division and specifically consists of the following three parts:

[0050] High voltage arm: The high voltage end of the primary ceramic capacitor 11 is fixedly connected to the outer wall of the conductive rod 5 to form a voltage divider circuit high voltage arm, which directly carries the primary high voltage.

[0051] Low-voltage arm: The secondary capacitor 12 and the primary ceramic capacitor 11 are connected in series to form the low-voltage arm of the voltage divider circuit;

[0052] Signal output: Obtain the low voltage signal after voltage division across the secondary capacitor 12.

[0053] All functional modules (conductive rod 5, temperature monitoring module, current measurement module, voltage measurement module, capacitance monitoring module, and connector sockets for secondary signal transmission components) are encapsulated in an epoxy resin shell using an epoxy resin integral casting and curing process, forming a fully sealed, single integrated structure. This design achieves three core advantages:

[0054] Deep integration of functions: The RTD temperature sensor 6 is tightly integrated with the current and voltage transformer modules in three-dimensional space, eliminating the need for independent sensor wiring space.

[0055] Extreme space compression: The internal components are optimized through coaxial arrangement and three-dimensional stacking to minimize the overall volume, which is close to the size of a standard sleeve; Plug and play interface: Connector 16 directly outputs three types of signals (current, voltage, temperature) transmitted via multi-core shielded twisted pair cable 15, seamlessly connecting to external intelligent electronic devices (IEDs) and greatly simplifying the complexity of field wiring.

[0056] This utility model innovatively integrates four major functions—real-time temperature monitoring, wideband non-saturated current measurement based on Rogowski coils, capacitive voltage divider measurement, and capacitor condition monitoring reflecting insulation degradation—into a single standardized bushing structure, thus solving three major pain points in the automation transformation of ring main units:

[0057] Space constraints: It can directly replace the original standard sleeve installation without taking up additional cabinet space.

[0058] Upgrade cost: Eliminating the purchase and expansion costs of independent PT / CT / temperature sensors reduces costs by over 60% (based on typical scenario calculations).

[0059] Safety Early Warning: The embedded temperature sensor and capacitor monitoring network form a dual insulation failure early warning mechanism, significantly improving equipment reliability. It is particularly suitable for space-constrained compact ring main unit retrofitting scenarios, providing a cost-effective solution for intelligent upgrades of distribution networks.

[0060] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. An integrated bushing-type electronic current-voltage combination transformer with temperature monitoring, characterized by, The secondary signal transmission assembly, the insulating shell, the conductive rod arranged in the insulating shell, the temperature monitoring module, the current measuring module, the voltage measuring module and the capacitance monitoring module are included, wherein the side of the insulating shell is provided with a boss, and the conductive rod penetrates through the center of the insulating shell; The capacitance monitoring module includes a capacitance terminal and a cylindrical capacitance induction net, the capacitance induction net is coaxially arranged with the conductive rod, the capacitance terminal is embedded on the boss, and the capacitance terminal is connected with the capacitance induction net; The current measuring module includes a Rogowski coil sleeved outside the capacitance induction net; The voltage measuring module includes a primary ceramic capacitor fixed outside the conductive rod and a secondary capacitor connected in series with the primary ceramic capacitor; The secondary signal transmission assembly is embedded on the boss, and the Rogowski coil, the secondary capacitor and the temperature monitoring module are connected with the secondary signal transmission assembly.

2. The integrated bushing-type electronic current-voltage combination transformer with temperature monitoring according to claim 1, characterized in that, The secondary signal transmission assembly includes a connector female seat, a connector, a connector male head and a multi-core shielded twisted pair wire, wherein the connector female seat is embedded in the boss, the connector female seat collects the output signal lines of the Rogowski coil, the secondary capacitor and the temperature monitoring module; the two ends of the multi-core shielded twisted pair wire are respectively connected with the connector male head and the connector, the connector male head is connected with the connector female seat, and the connector is used for outputting signals to external equipment.

3. The integrated bushing-type electronic current-voltage combination transformer with temperature monitoring according to claim 2, characterized in that, The metal shell of the connector female seat is electrically connected with a grounding terminal through a shielding wire, and the grounding terminal is arranged on the boss.

4. The integrated bushing-type electronic current-voltage combination transformer with temperature monitoring according to claim 3, characterized in that, The shielding layer of the multi-core shielded twisted pair wire, the connector male head shell and the connector female seat shell are electrically connected, and a ground anti-interference loop is formed.

5. The integrated bushing-type electronic current-voltage combination transformer with temperature monitoring according to claim 2, characterized in that, The temperature monitoring module includes a thermal resistance temperature sensor embedded in the insulating shell, the thermal resistance temperature sensor is located outside the capacitance induction net, and the signal line of the thermal resistance temperature sensor is connected to the connector female seat.

6. The integrated bushing-type electronic current-voltage combination transformer with temperature monitoring according to claim 2, characterized in that, The Rogowski coil includes a non-magnetic coil frame and a coil wire wound on the coil frame, the two ends of the coil wire are connected to the connector female seat, and the Rogowski coil outputs a voltage signal proportional to the derivative of the measured current.

7. The integrated bushing-type electronic current-voltage combination transformer with temperature monitoring according to claim 1, characterized in that, The insulating shell adopts a tubular structure cast by epoxy resin, the front end and the rear end of the insulating shell are a conical body and a cylindrical body respectively, the middle part of the insulating shell is provided with a flange plate, and one side of the flange plate extends radially to form the boss.

8. The integrated bushing-type electronic current-voltage combination transformer with temperature monitoring according to claim 7, characterized in that, The mounting surface of the flange plate is provided with a sealing groove.

9. The integrated bushing-type electronic current-voltage combination transformer with temperature monitoring according to claim 1, characterized in that, The secondary capacitor is arranged inside the boss.

Images