Voltage and current combined electronic transformer with accurate measurement function

Abstract

The utility model discloses a voltage and current combined electronic transformer with an accurate measurement function, which relates to the technical field of transformers and comprises a current amorphous iron core, a current coil, a non-inductive resistor, a primary ceramic capacitor and a secondary capacitor. According to the utility model, the primary ceramic capacitor is fixed on the conducting rod to form the primary capacitor, the primary capacitor and the secondary capacitor are used for voltage division and secondary voltage signals are output, and the shielded twisted pair is used for output, so that the signal transmission anti-interference capability is strong, and the product precision is high; the current part adopts a low-energy-consumption small-iron-core coil principle, low-temperature-drift non-inductive metal film resistors are adopted in the circuit to output small voltage signals in parallel, the temperature drift coefficient is small, shielded twisted pairs are adopted for output, the anti-interference capability of transmission signals is high, and the product precision is high; and the secondary voltage signal device and the current sensor take epoxy resin as insulating filler and are poured and molded together to form the full-sealed maintenance-free voltage and current combined electronic transformer.

Description

Technical Field

[0001] The utility model relates to the technical field of mutual inductors, in particular to a voltage and current combined electronic mutual inductor with a precise measurement function. Background Art

[0002] With the development of smart grids, ring main units (RMUs), crucial equipment for segmenting, branching, demarcating, and connecting distribution networks, need to feature adaptive, comprehensive local feeder automation, short-circuit / ground fault detection, and local line selection, segment location, and isolation for single-phase ground faults. These functions also support the primary and secondary closing of substation outgoing line switches. To ensure stable and reliable electrical performance of these devices, voltage sensors providing current measurement and protection signals must fully embody the characteristics and requirements of "low loss, energy conservation and environmental protection, high efficiency, cost-effectiveness, stable and reliable performance, and miniaturization." To meet the State Grid's requirements for refined line loss management and achieve line loss measurement on distribution network branches, new requirements are being placed on primary voltage transformers to ensure accurate measurement. With the rapid advancement of electronic technology, microcomputer-based relay protection devices have gradually taken a leading position. In relay protection and measurement, the control portion of energy flow and information flow are separated, eliminating the need for high-power output transformer sampling for monitoring equipment. Furthermore, with the rapid development of the power industry and the increasing complexity of power grids, intelligent voltage transformers are being widely used to improve power factor and grid quality.

[0003] The space inside the ring main unit is extremely small and has a fully insulated structure, which is not conducive to the direct installation of traditional transformers and large electronic current transformers plus electronic voltage transformers. With the deepening of distribution network automation transformation, a large number of secondary devices have been put into use, but how to collect signals, measure, monitor and protect them is a difficult problem. Special voltage transformers and current transformers are required, which are costly and occupy a lot of space. Especially for the transformation of ring main units that have been put into operation, it is extremely difficult and costly to add traditional transformer devices. Utility Model Content

[0004] The purpose of the present invention is to provide a voltage and current combined electronic transformer with precise measurement function, so as to solve the problems raised in the above background technology.

[0005] To solve the above technical problems, the present utility model provides the following technical solution: A combined voltage and current electronic transformer with precise measurement function, comprising a current housing, a voltage housing, and a conductive rod. The conductive rod is disposed inside the voltage housing in a penetrating manner. The current housing is sleeved on the outer wall of the voltage housing. Inside the current housing, there are a current amorphous core and a current coil. The current amorphous core is perpendicular to the conductive rod. The current coil is wound around the outer wall of the current amorphous core. A non-inductive resistor is connected in parallel to the current coil. Inside the voltage housing, there is a primary ceramic capacitor, which is fixedly connected to the outer wall of the conductive rod. The primary ceramic capacitor and a secondary capacitor are connected in series. The current housing and the voltage housing are fixedly sealed by epoxy resin perfusion.

[0006] Further, the current coil outputs a current signal through a current shielded twisted pair. A resistor and a voltage shielded twisted pair are connected in parallel to the secondary capacitor. The current amorphous core is annular, and the secondary capacitor is disposed inside the current housing.

[0007] Further, an outer shielding net is disposed inside the voltage housing outside the primary ceramic capacitor. The primary ceramic capacitor is fixedly connected to the outer wall of the conductive rod through a plurality of primary capacitor fixing members. The outer shielding net is fixedly connected to the voltage housing through an outer shielding net fixing member.

[0008] Further, the voltage housing further includes a temperature reduction adjustment box and a temperature reduction pipeline. The temperature reduction adjustment box is disposed on the outer wall of the voltage housing. The temperature reduction pipeline is disposed inside the epoxy resin. The temperature reduction pipeline communicates with the temperature reduction adjustment box. Both the temperature reduction adjustment box and the temperature reduction pipeline are made of insulating materials.

[0009] Further, an inlet liquid cavity and an outlet liquid cavity are provided inside the temperature reduction adjustment box. One end of the temperature reduction pipeline communicates with the inlet liquid cavity, and the other end of the temperature reduction pipeline communicates with the outlet liquid cavity. A condenser is provided inside the inlet liquid cavity. A liquid infusion channel is provided between the inlet liquid cavity and the outlet liquid cavity.

[0010] Further, a first sealing plate rotatably connected is provided on the inner wall of the liquid infusion channel near the outlet liquid cavity side. A second sealing plate movably connected is provided inside the outlet liquid cavity. A servo electric cylinder is provided outside the outlet liquid cavity of the temperature reduction adjustment box. The output end of the servo electric cylinder is fixedly connected to the center of the outer wall of the second sealing plate.

[0011] Further, a first connecting shaft is provided at the top of the inner wall of the liquid infusion channel. The top of the first sealing plate is movably sleeved on the outer wall of the first connecting shaft. A first torsion spring is provided between the first connecting shaft and the first sealing plate.

[0012] Furthermore, a number of rotatably connected sleeves are provided on the inner wall of the cooling pipeline. A third sealing plate is provided on the outer wall of the sleeve inside the cooling pipeline. A stop block matching the third sealing plate is provided on the inner wall of the cooling pipeline, and the stop block is arranged on the side of the inner wall of the cooling pipeline away from the sleeve.

[0013] Furthermore, a number of second connecting shafts are provided on the inner wall of the cooling pipeline. The sleeve is movably sleeved outside the second connecting shaft. A second torsion spring is provided between the second connecting shaft and the third sealing plate, and the stop block is arranged at one end of the inner wall of the cooling pipeline close to the liquid outlet cavity.

[0014] Furthermore, the cooling pipeline includes a first pipeline, a second pipeline, a third pipeline and a fourth pipeline. The first pipeline, the second pipeline, the third pipeline and the fourth pipeline are distributed in a cross shape inside the epoxy resin. The first pipeline is communicated with the bottom of the liquid outlet cavity. The first pipeline is communicated with the second pipeline through a first connecting pipe. The second pipeline is communicated with the third pipeline through a second connecting pipe. The third pipeline is communicated with the fourth pipeline through a third connecting pipe. The fourth pipeline is communicated with the top of the outer wall of the liquid inlet cavity.

[0015] Compared with the prior art, the beneficial effects achieved by the utility model are as follows:

[0016] 1. The utility model is provided with a current amorphous core, a current coil, a non-inductive resistor, a primary ceramic capacitor and a secondary capacitor. The current signal is transmitted through a current shielded twisted pair. The primary ceramic capacitor is fixed on a conductive rod through a primary capacitor fixing piece to form a primary capacitor. A voltage division ratio is formed through the primary ceramic capacitor and the secondary capacitor. The secondary capacitor is potted in the current housing to convert a secondary voltage signal, and the voltage signal is transmitted through a voltage shielded twisted pair. The secondary voltage signal device and the current sensor use epoxy resin as an insulating filler and are potted together to form a fully sealed and maintenance-free voltage-current combined electronic transformer. For the voltage part, the primary ceramic capacitor is fixed on the conductive rod to form a primary capacitor, which is used for voltage division with the secondary capacitor to output a secondary voltage signal. The signal is output by a shielded twisted pair, and the signal transmission has strong anti-interference ability and high product accuracy. For the current part, the principle of a low-energy consumption and small iron core coil is adopted. A low-temperature drift non-inductive metal film resistor is used in the circuit to output a small voltage signal in parallel, and the temperature drift coefficient is small. The signal is output by a shielded twisted pair, and the signal transmission has strong anti-interference ability and high product accuracy. By adopting non-traditional voltage transformer and current transformer technologies, the electronic voltage-current transformer is combined into two fully sealed wholes, which are combined and fixed, and the original cable and each cable accessory can be directly replaced with this combined electronic transformer. The acquisition of voltage and current signals, measurement, monitoring and protection are realized. This combined electronic voltage and current transformer is installed on an air-insulated or gas-insulated switchgear, and its volume is one-sixth of that of a traditional voltage and current transformer, its weight is one-fifth of that of a traditional voltage and current transformer, and its energy consumption is less than one-tenth of that of a traditional voltage and current transformer. It is applied to the primary and secondary integrated ring main unit of distribution equipment to meet the development needs of "digitization, intelligence and networking" in various fields of the power industry.

[0017] 2. In the utility model, the cooling and temperature regulating box is used for cooling down and transporting the coolant. The cooling pipeline provides a flow channel for the coolant inside the epoxy resin. The coolant cools down the epoxy resin inside the cooling pipeline, which can effectively improve the cooling performance of the epoxy resin, and then improve the cooling performance of the transformer. It can effectively avoid the overheating of the transformer caused by the common operation of current and voltage, and then improve the service life of the transformer. The cooling insulating oil inside the liquid outlet cavity is pushed into the cooling pipeline. The cooling insulating oil inside the cooling pipeline cools down the epoxy resin, which can effectively reduce the operating temperature of the transformer and effectively avoid the damage of the transformer caused by overheating. After the cooling insulating oil enters the cooling pipeline for circulation, it returns to the liquid inlet cavity of the cooling and temperature regulating box. At this time, the first sealing plate seals the liquid infusion channel, and the cooling insulating oil inside the liquid inlet cavity stays inside the liquid inlet cavity and cannot enter the liquid outlet cavity. The condenser inside the liquid inlet cavity cools down the cooling insulating oil inside the liquid inlet cavity, thereby improving the subsequent cooling effect of the cooling insulating oil. Description of the Drawings

[0018] The accompanying drawings are used to provide a further understanding of the present utility model and form a part of the description. Together with the embodiments of the present utility model, they are used to explain the present utility model and do not constitute a limitation to the present utility model. In the accompanying drawings:

[0019] Figure 1 is the front view of the whole of the present utility model;

[0020] Figure 2 is the front sectional view of the whole of the present utility model;

[0021] Figure 3 is the present utility model Figure 2 the enlarged schematic view at position A in;

[0022] Figure 4 is the side sectional view of the whole of the present utility model;

[0023] Figure 5 is the circuit schematic diagram of the current part of the present utility model;

[0024] Figure 6 is the circuit schematic diagram of the voltage part of the present utility model;

[0025] Figure 7 is the wiring schematic diagram of the current part of the present utility model;

[0026] Figure 8 is the wiring schematic diagram of the voltage part of the present utility model;

[0027] Figure 9 is the front view of the temperature reduction adjustment box and the temperature reduction pipeline of the present utility model;

[0028] Figure 10 is the present utility model Figure 9 the side sectional view of;

[0029] Figure 11 is the front sectional view of the temperature reduction adjustment box of the present utility model;

[0030] Figure 12 is the front sectional view of another state of the temperature reduction adjustment box of the present utility model;

[0031] In the figure: 1. current housing; 2. voltage housing; 3. current amorphous core; 4. current coil; 5. non-inductive resistor; 6. current shielded twisted pair; 7. conductive rod; 8. primary ceramic capacitor; 9. secondary capacitor; 10. voltage shielded twisted pair; 11. outer shielding mesh; 12. primary capacitor fixing part; 13. outer shielding mesh fixing part; 14. cooling adjustment box; 15. cooling pipeline; 16. liquid inlet cavity; 17. liquid outlet cavity; 18. condenser; 19. infusion channel; 20. first sealing plate; 21. second sealing plate; 22. servo cylinder; 23. first connecting shaft; 24. sleeve; 25. third sealing plate; 26. block; 27. second connecting shaft; 28. first pipeline; 29. second pipeline; 30. third pipeline; 31. fourth pipeline; 32. first connecting pipe; 33. second connecting pipe; 34. third connecting pipe. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] See also Figures 1-12The utility model provides a technical solution: a voltage and current combined electronic mutual inductor with precise measurement function, including a current housing 1, a voltage housing 2 and a conductive rod 7, the conductive rod 7 is arranged through the inner side of the voltage housing 2, the current housing 1 is sleeved on the outer wall of the voltage housing 2, a current amorphous iron core 3 and a current coil 4 are arranged inside the current housing 1, the current amorphous iron core 3 and the conductive rod 7 are perpendicular to each other, the current coil 4 is wound around the outer wall of the current amorphous iron core 3, the current coil 4 is connected in parallel with a non-inductive resistor 5, a primary ceramic capacitor 8 is arranged inside the voltage housing 2, and the primary ceramic capacitor 8 is fixedly connected to the outer wall of the conductive rod 7, the The primary ceramic capacitor 8 and the secondary capacitor 9 are connected in series, and the current housing 1 and the voltage housing 2 are sealed and fixed by epoxy resin perfusion; the voltage housing 2 also includes a cooling regulating box 14 and a cooling pipeline 15, the cooling regulating box 14 is provided on the outer wall of the voltage housing 2, the cooling pipeline 15 is provided on the inner side of the epoxy resin, the cooling pipeline 15 is connected to the cooling regulating box 14, and the cooling regulating box 14 and the cooling pipeline 15 are both made of insulating material; a liquid inlet cavity 16 and a liquid outlet cavity 17 are provided inside the cooling regulating box 14, one end of the cooling pipeline 15 is connected to the liquid inlet cavity 16, and the other end of the cooling pipeline 15 is connected to the liquid outlet cavity 17, A condenser 18 is provided inside the liquid inlet chamber 16, and an infusion channel 19 is provided between the liquid inlet chamber 16 and the liquid outlet chamber 17; a first sealing plate 20 is provided on the inner wall of the infusion channel 19 near the liquid outlet chamber 17 to be rotatably connected, and a second sealing plate 21 is provided inside the liquid outlet chamber 17 to be movably connected. The cooling regulating box 14 is provided with a servo electric cylinder 22 on the outside of the liquid outlet chamber 17, and the output end of the servo electric cylinder 22 is fixedly connected to the center of the outer wall of the second sealing plate 21; a first connecting shaft 23 is provided on the top of the inner wall of the infusion channel 19, and the top of the first sealing plate 20 is movably sleeved on the outer wall of the first connecting shaft 23, and the first connecting shaft 23 and the first sealing plate A first torsion spring is provided between the plates 20; a plurality of rotatably connected sleeves 24 are provided on the inner wall of the cooling pipeline 15, and a third sealing plate 25 is provided on the outer wall of the sleeve 24 inside the cooling pipeline 15, and a stopper 26 matching the third sealing plate 25 is provided on the inner wall of the cooling pipeline 15, and the stopper 26 is provided on the side of the inner wall of the cooling pipeline 15 away from the sleeve 24; a plurality of second connecting shafts 27 are provided on the inner wall of the cooling pipeline 15, and the sleeve 24 is movably sleeved on the outside of the second connecting shaft 27, a second torsion spring is provided between the second connecting shaft 27 and the third sealing plate 25, and the stopper 26 is provided on the inner wall of the cooling pipeline 15 near the end of the liquid outlet cavity 17.

[0034] The current coil 4 outputs a current signal through the current shielding twisted pair 6. A resistor and a voltage shielding twisted pair 10 are connected in parallel to the secondary capacitor 9. The current amorphous iron core 3 is annular, and the secondary capacitor 9 is arranged inside the current housing 1. An external shielding net 11 is arranged outside the primary ceramic capacitor 8 inside the voltage housing 2. The primary ceramic capacitor 8 is fixedly connected to the outer wall of the conductive rod 7 through a plurality of primary capacitor fixing members 12. The external shielding net 11 is fixedly connected to the voltage housing 2 through an external shielding net fixing member 13.

[0035] The cooling pipeline 15 includes a first pipeline 28, a second pipeline 29, a third pipeline 30 and a fourth pipeline 31. The first pipeline 28, the second pipeline 29, the third pipeline 30 and the fourth pipeline 31 are distributed in a cross shape inside the epoxy resin. The first pipeline 28 is communicated with the bottom of the liquid outlet cavity 17. The first pipeline 28 is communicated with the second pipeline 29 through a first connecting pipe 32. The second pipeline 29 is communicated with the third pipeline 30 through a second connecting pipe 33. The third pipeline 30 is communicated with the fourth pipeline 31 through a third connecting pipe 34. The fourth pipeline 31 is communicated with the top of the outer wall of the liquid inlet cavity 16. The first pipeline 28, the second pipeline 29, the third pipeline 30 and the fourth pipeline 31 cooperate to perform cooling treatment on the epoxy resin internally in different directions and positions, and the cooling effect on the mutual inductor is better. The cooling insulating oil inside the cooling adjustment box 14 enters the epoxy resin from the first pipeline 28 of the cooling pipeline 15, then enters the second pipeline 29 through the first connecting pipe 32, then enters the third pipeline 30 through the second connecting pipe 33, and then enters the fourth pipeline 31 through the third connecting pipe 34. The cooling insulating oil in the fourth pipeline 31 enters the cooling adjustment box 14 to ensure that the cooling insulating oil inside the cooling pipeline 15 returns to the cooling adjustment box 14 for cooling treatment after flowing.

[0036] The working principle of the present utility model:

[0037] Referring to the attached Figures 1-12 description, the present utility model is provided with a current amorphous iron core 3, a current coil 4, a non-inductive resistor 5, a primary ceramic capacitor 8 and a secondary capacitor 9;

[0038] The current signal is transmitted out through the current shielding twisted pair 6. The primary ceramic capacitor 8 is fixed on the conductive rod through the primary capacitor fixing member 12 to form a primary capacitor. A voltage division ratio is formed through the primary ceramic capacitor 8 and the secondary capacitor 9. The secondary capacitor 9 is poured inside the current housing 1 to convert a secondary voltage signal, and the voltage signal is transmitted through the voltage shielding twisted pair 10. The secondary voltage signal device and the current sensor use epoxy resin as an insulating filler and are poured and molded together to form a fully sealed maintenance-free voltage-current combined electronic mutual inductor;

[0039] The current part of this utility model adopts the principle of low-power iron core, and the voltage part adopts the principle of pure capacitor voltage division. The principle is explained below:

[0040] The voltage sensor uses the principle of pure capacitive voltage division. In order to prevent the primary capacitor breakdown from affecting the secondary circuit, a discharge tube is connected in parallel with the secondary capacitor in the voltage secondary signal converter. When the primary capacitor breaks down, the voltage across the secondary capacitor is directly zero, protecting the secondary circuit from damage. At the same time, a resistor is connected in parallel with the secondary capacitor to adjust the phase difference.

[0041] The current transformer uses a small core coil low-power principle: the current transformer consists of a primary winding with a small core and a secondary winding with minimal losses. The secondary winding is connected to the integrated element Ra, so its secondary output is a voltage signal. The voltage drop Us generated by the secondary current 12 across the integrated element Ra has an amplitude proportional to the primary current and is in phase. Moreover, the smaller the internal losses of the transformer and the secondary power required by the load, the wider the measurement range and the higher the accuracy.

[0042] The components inside the entire product are arranged in an orderly and intelligent combination to avoid electromagnetic interference, output small voltage signals, and have no mutual interference, resulting in superior performance;

[0043] The voltage part uses a primary ceramic capacitor fixed on the conductive rod to form a primary capacitor, which is divided with the secondary capacitor to output a secondary voltage signal. The output is made of shielded twisted pair cable, which has strong anti-interference ability of the transmission signal and high product precision.

[0044] The secondary voltage signal is partially injected into the current sensor, so that the voltage and current sensors are integrated together, which is both separate and combined, easy to install and takes up less space;

[0045] The current part adopts the principle of low-energy small iron core coil. The circuit uses low-temperature drift non-inductive metal film resistors in parallel to output small voltage signals. The temperature drift coefficient is small. When working outdoors at -25℃ to +75℃, the product error range remains unchanged. The output uses shielded twisted pair cable, the transmission signal has strong anti-interference ability and high product precision.

[0046] This utility model can measure, monitor and protect voltage and current, replacing traditional cables, voltage transformers and current transformers. One product has the functions of the above three products at the same time. The key energy consumption is less than one-tenth of the original. The voltage and current output signals are independent and do not interfere with each other. The transmission capacity is strong and can be connected in parallel with 15-meter-long shielded twisted-pair cables. The structure with unchanged terminal accuracy is easy to install, reduces on-site wiring, saves space and is convenient for maintenance. The product outputs a small voltage signal that will not harm the controlled equipment. It can be directly connected to secondary integrated automation equipment such as instruments and relay protection devices to realize voltage and current measurement, monitoring, protection and zero-sequence functions. It has complete functions, is simple and convenient to install and use, reduces energy consumption during operation, and does not require equipment maintenance.

[0047] The utility model is compact, flexible, and easy to install. It does not require destroying the original design. In particular, for cabinets that have been put into operation, the product can be installed in the existing space without changing the original equipment or adding new space. It can save users a lot of costs and greatly reduce the difficulty of construction. It enables many ring network cabinets that were not suitable for transformation to obtain measurement, monitoring, and protection functions, and provides a new solution for the distribution network automation secondary equipment of the ring network cabinet. This product can directly replace the original cables and cable accessories with the existing bushing-type voltage and current combined electronic mutual inductor, adding voltage and current measurement, monitoring, and protection functions, greatly reducing the difficulty of on-site construction and the risk of construction failure. It does not occupy any additional space.

[0048] This utility model adopts non-traditional voltage transformer and current transformer technology. The electronic voltage and current transformers are combined into two fully sealed units. The combination is fixed, and the original cables and cable accessories can be directly replaced with this combined electronic transformer. The voltage and current signals are collected, and measurement, monitoring, and protection are achieved. This electronic voltage and current combination transformer is installed on air-insulated or gas-insulated switchgear. It is one-sixth the volume, one-fifth the weight, and less than one-tenth the energy consumption of traditional voltage and current transformers. It is used in primary and secondary integrated ring network cabinets of power distribution equipment to meet the development needs of "digitalization, intelligence, and networking" in various fields of the power industry.

[0049] The cooling regulating box 14 in the present invention is used to provide cooling and delivery work for the coolant, and the cooling pipe 15 provides a flow channel for the coolant inside the epoxy resin. The coolant cools the epoxy resin inside the cooling pipe 15, which can effectively improve the cooling performance of the epoxy resin, thereby improving the cooling performance of the mutual inductor, and effectively avoiding excessive heat in the mutual inductor caused by the combined work of current and voltage, thereby increasing the service life of the mutual inductor.

[0050] The liquid inlet chamber 16 inside the cooling regulating box 14 is used to receive and store the cooling insulating oil transported by the cooling pipeline 15. The liquid outlet chamber 17 is used to withdraw the cooling insulating oil inside the cooling regulating box 14 into the cooling pipeline 15. The infusion channel 19 is used to connect the liquid inlet chamber 16 and the liquid outlet chamber 17. The cooling insulating oil inside the liquid inlet chamber 16 enters the liquid outlet chamber 17 through the infusion channel 19. The first sealing plate 20 can seal and block the infusion channel 19. The infusion channel 19 can be opened and closed by adjusting the angle of the first sealing plate 20. The second sealing plate 21 performs a sealing process inside the liquid outlet chamber 17. At the same time, the second sealing plate 21 is adjusted to move linearly to squeeze and discharge the cooling insulating oil inside the liquid outlet chamber 17.

[0051] Adjust the servo electric cylinder 22 to perform telescopic adjustment. The servo electric cylinder 22 drives the second sealing plate 21 to perform linear motion adjustment inside the liquid outlet cavity 17. When adjusting the servo electric cylinder 22 to extend, the cooling insulating oil inside the liquid outlet cavity 17 is pushed outwards. The second sealing plate 21 contacts the first sealing plate 20. When the second sealing plate 21 performs linear motion adjustment, the second sealing plate 21 can push the first sealing plate 20. The first sealing plate 20 retracts into the liquid infusion channel 19 and performs a blocking and sealing treatment on the liquid infusion channel 19. At this time, the cooling insulating oil inside the liquid inlet cavity 16 stops entering the liquid outlet cavity 17, and at the same time, it also prevents the cooling insulating oil inside the liquid outlet cavity 17 from entering the liquid inlet cavity 16 during the extrusion process, ensuring that the cooling insulating oil in the liquid outlet cavity 17 enters the temperature reduction pipeline 15 under the extrusion action. At this time, the second sealing plate 21 continues to move downward, pushing the cooling insulating oil inside the liquid outlet cavity 17 into the temperature reduction pipeline 15. The cooling insulating oil inside the temperature reduction pipeline 15 performs a temperature reduction and cooling treatment on the epoxy resin, which can effectively reduce the operating temperature of the mutual inductor and effectively prevent the mutual inductor from being damaged due to excessive temperature;

[0052] When the second sealing plate 21 pushes the cooling insulating oil inside the liquid outlet cavity 17 into the temperature reduction pipeline 15, the cooling insulating oil enters the temperature reduction pipeline 15 for circulation and then returns to the liquid inlet cavity 16 of the temperature reduction adjustment box 14. At this time, the first sealing plate 20 seals the liquid infusion channel 19. The cooling insulating oil inside the liquid inlet cavity 16 stays inside the liquid inlet cavity 16 and cannot enter the liquid outlet cavity 17. The condenser 18 inside the liquid inlet cavity 16 cools the cooling insulating oil inside the liquid inlet cavity 16, thereby improving the subsequent temperature reduction and cooling effect of the cooling insulating oil;

[0053] Adjust the servo electric cylinder 22 to contract. The servo electric cylinder 22 drives the second sealing plate 21 to move upward. The second sealing plate 21 continues to move upward and separates from the first sealing plate 20 and no longer contacts. The first sealing plate 20 loses the pressure of the second sealing plate 21. The first sealing plate 20 performs elastic rebound and reset under the action of the first torsion spring. The top of the first sealing plate 20 swings upward along the first connecting shaft 23, and the first sealing plate 20 separates from the liquid infusion channel 19, opening the liquid infusion channel 19. The liquid inlet cavity 16 and the liquid outlet cavity 17 are communicated. The cooled cooling insulating oil enters the liquid outlet cavity 17 from the liquid inlet cavity 16. Then adjust the servo electric cylinder 22 to extend, and again push the cooling insulating oil inside the liquid outlet cavity 17 into the temperature reduction pipeline 15, realizing the circulation drive of the cooling insulating oil and ensuring the temperature reduction and cooling treatment effect on the mutual inductor;

[0054] After the cooling insulating oil enters the cooling pipeline 15 under the push of the second sealing plate 21, the cooling insulating oil directly impacts and pushes the third sealing plate 25, and the third sealing plate 25 swings under the push of the cooling insulating oil. The cooperation of the second connecting shaft 27 and the sleeve 24 ensures the stability of the swing of the third sealing plate 25. The second torsion spring provides elastic torsional support for the third sealing plate 25. When the cooling insulating oil enters the cooling pipeline 15 under the push of the second sealing plate 21, the cooling insulating oil impacts and pushes the third sealing plate 25, and the third sealing plate 25 swings. The second torsion spring is compressed, and the third sealing plate 25 opens the passage of the cooling pipeline 15, and the cooling insulating oil moves normally along the cooling pipeline 15; when the second sealing plate 21 moves up and does not squeeze the cooling insulating oil, the cooling insulating oil impacts the third sealing plate 25. The impact force of the plate 25 is reduced, the second torsion spring rebounds and automatically resets the third sealing plate 25, the block 26 blocks the third sealing plate 25, and the third sealing plate 25 closes the passage of the cooling pipeline 15 again, and limits the position of the block 26, so that the third sealing plate 25 will not swing across the block 26, so that the third sealing plate 25 and the second torsion spring cooperate to form a one-way valve, which can effectively prevent the cooling insulating oil from flowing back. The cooling insulating oil is continuously transported forward along the cooling pipeline 15 under the push of the second sealing plate 21 inside the liquid outlet chamber 17, which can effectively ensure that the cooling insulating oil inside the cooling pipeline 15 can all participate in the circulation process, and at the same time ensure that the cooling insulating oil inside the cooling pipeline 15 undergoes normal heat exchange processing, thereby improving the cooling treatment effect of the cooling pipeline 15.

[0055] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A combined voltage and current electronic transformer with precise measurement function, comprising a current outer shell (1), a voltage outer shell (2) and a conductive rod (7), characterized in that: The conductive rod (7) is disposed through the inside of the voltage housing (2). The current housing (1) is sleeved on the outer wall of the voltage housing (2). Inside the current housing (1), there are a current amorphous iron core (3) and a current coil (4). The current amorphous iron core (3) is perpendicular to the conductive rod (7). The current coil (4) is wound around the outer wall of the current amorphous iron core (3). A non-inductive resistor (5) is connected in parallel with the current coil (4). Inside the voltage housing (2), there is a primary ceramic capacitor (8). The primary ceramic capacitor (8) is fixedly connected to the outer wall of the conductive rod (7). The primary ceramic capacitor (8) and the secondary capacitor (9) are connected in series. The current housing (1) and the voltage housing (2) are fixedly sealed by epoxy resin perfusion.

2. The voltage and current combined electronic transformer with precise measurement function according to claim 1, characterized in that: The current coil (4) outputs a current signal through a current shielding twisted pair (6). A resistor and a voltage shielding twisted pair (10) are connected in parallel with the secondary capacitor (9). The current amorphous iron core (3) is annular. The secondary capacitor (9) is disposed inside the current housing (1).

3. The combined voltage and current electronic transformer with precise measurement function according to claim 1, characterized in that: Inside the voltage housing (2), an outer shielding net (11) is disposed outside the primary ceramic capacitor (8). The primary ceramic capacitor (8) is fixedly connected to the outer wall of the conductive rod (7) through a plurality of primary capacitor fixing members (12). The outer shielding net (11) is fixedly connected to the voltage housing (2) through an outer shielding net fixing member (13).

4. A combined voltage and current electronic transformer with precise measurement function according to claim 1, characterized in that: The voltage housing (2) further includes a temperature reduction adjustment box (14) and a temperature reduction pipeline (15). The temperature reduction adjustment box (14) is disposed on the outer wall of the voltage housing (2). The temperature reduction pipeline (15) is disposed inside the epoxy resin. The temperature reduction pipeline (15) communicates with the temperature reduction adjustment box (14). Both the temperature reduction adjustment box (14) and the temperature reduction pipeline (15) are made of insulating materials.

5. The voltage-current combined electronic transformer with accurate measurement function according to claim 4, characterized in that: Inside the temperature reduction adjustment box (14), there are a liquid inlet chamber (16) and a liquid outlet chamber (17). One end of the temperature reduction pipeline (15) communicates with the liquid inlet chamber (16). The other end of the temperature reduction pipeline (15) communicates with the liquid outlet chamber (17). A condenser (18) is disposed inside the liquid inlet chamber (16). There is a liquid infusion channel (19) between the liquid inlet chamber (16) and the liquid outlet chamber (17).

6. The combined voltage and current electronic transformer with precise measurement function according to claim 5, characterized in that: On the inner wall of the liquid infusion channel (19) near the side of the liquid outlet chamber (17), there is a first sealing plate (20) rotatably connected. Inside the liquid outlet chamber (17), there is a second sealing plate (21) movably connected. Outside the liquid outlet chamber (17) of the temperature reduction adjustment box (14), there is a servo electric cylinder (22). The output end of the servo electric cylinder (22) is fixedly connected to the center of the outer wall of the second sealing plate (21).

7. The voltage-current combined electronic transformer with accurate measurement function according to claim 6, characterized in that: At the top of the inner wall of the liquid infusion channel (19), there is a first connecting shaft (23). The top of the first sealing plate (20) is movably sleeved on the outer wall of the first connecting shaft (23). There is a first torsion spring between the first connecting shaft (23) and the first sealing plate (20).

8. A combined voltage and current electronic transformer with precise measurement function according to claim 6, characterized in that: The inner wall of the cooling pipeline (15) is provided with a number of sleeves (24) rotatably connected. The outer wall of the sleeve (24) is provided with a third sealing plate (25) inside the cooling pipeline (15). The inner wall of the cooling pipeline (15) is provided with a stop block (26) matching the third sealing plate (25). The stop block (26) is arranged on the side of the inner wall of the cooling pipeline (15) far from the sleeve (24).

9. The voltage and current combined electronic transformer with precise measurement function according to claim 8, characterized in that: The inner wall of the cooling pipeline (15) is provided with a number of second connecting shafts (27). The sleeve (24) is movably sleeved outside the second connecting shaft (27). A second torsion spring is arranged between the second connecting shaft (27) and the third sealing plate (25). And the stop block (26) is arranged at one end of the inner wall of the cooling pipeline (15) close to the liquid outlet cavity (17).

10. A combined voltage and current electronic transformer with precise measurement function according to claim 6, characterized in that: The cooling pipeline (15) includes a first pipeline (28), a second pipeline (29), a third pipeline (30) and a fourth pipeline (31). The first pipeline (28), the second pipeline (29), the third pipeline (30) and the fourth pipeline (31) are distributed in a cross shape inside the epoxy resin. The first pipeline (28) is communicated with the bottom of the liquid outlet cavity (17). The first pipeline (28) is communicated with the second pipeline (29) through a first connecting pipe (32). The second pipeline (29) is communicated with the third pipeline (30) through a second connecting pipe (33). The third pipeline (30) is communicated with the fourth pipeline (31) through a third connecting pipe (34). The fourth pipeline (31) is communicated with the top of the outer wall of the liquid inlet cavity (16).

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