High-voltage combined electronic transformer and use method thereof

Abstract

The invention relates to the technical field of power system transformers, in particular to a high-voltage combined electronic transformer and a using method thereof. The high-voltage combined electronic mutual inductor comprises a current mutual inductor, a voltage mutual inductor, an insulation supporting structure and a merging unit, the voltage mutual inductor comprises at least one coupling capacitor and a voltage dividing capacitor which are stacked in sequence, and the current mutual inductor is connected with the coupling capacitor at the top end of the voltage mutual inductor; the voltage-dividing capacitors are arranged at the lower end of the voltage transformer, the insulating supporting structures are arranged on the outer sides of the coupling capacitors and the voltage-dividing capacitors, and signal transmission parts are arranged in the insulating supporting structures; the current transformer comprises a non-magnetic saturation Rogowski coil and a digital-to-analog conversion part, and the non-magnetic saturation Rogowski coil is used for testing primary current and converting the primary current into analog quantity; the digital-to-analog conversion part converts the analog quantity into a current optical signal and transmits the current optical signal to the merging unit through the signal transmission part; the voltage transformer transmits an obtained voltage optical signal to the merging unit.

Description

Technical Field

[0001] The present invention relates to the technical field of power system transformers, and particularly to a high-voltage combined electronic transformer and its usage method. Background Art

[0002] In the prior art, an open substation needs to use independent current transformers and independent voltage transformers for current and voltage measurement, which occupies a large area. Since transformers are used for electric energy metering, current measurement, automatic control, and relay protection in high-voltage power systems, a large number of current transformers and voltage transformers are used in high-voltage power systems. Due to the existence of problems such as core hysteresis and magnetic saturation in traditional current transformers, it is difficult to accurately measure current with a single set of current transformers; and when the core is magnetically saturated, the secondary output of the current transformer will be distorted, resulting in an increase in measurement error or misoperation of relay equipment. Traditional voltage transformers are prone to ferroresonance, resulting in distortion of the secondary output, which will also cause an increase in measurement error or misoperation of relay equipment. Summary of the Invention

[0003] The purpose of the present invention is to provide a high-voltage combined electronic transformer and its usage method to solve the problems of insufficient stability of ultra-high-voltage capacitive voltage transformers, magnetic saturation of current transformers, and large floor area in the prior art.

[0004] To solve the above problems, the present invention proposes a high-voltage combined electronic transformer, and the technical solution adopted is as follows: A high-voltage combined electronic transformer includes: a current transformer, a voltage transformer, an insulating support structure, and a merging unit. The voltage transformer includes at least one coupling capacitor and a voltage-dividing capacitor stacked in sequence. The current transformer is arranged at the top position of the high-voltage combined electronic transformer and is connected to the coupling capacitor at the top of the voltage transformer. The voltage-dividing capacitor is arranged at the lower end of the voltage transformer. The insulating support structure is arranged outside each coupling capacitor and voltage-dividing capacitor, and a signal transmission component connected to the current transformer is arranged inside it; the current transformer includes a non-magnetically saturated Rogowski coil with multiple taps and a digital-to-analog conversion component. The non-magnetically saturated Rogowski coil is used to measure the primary current of the high-voltage combined electronic transformer and convert the primary current into an analog quantity; the digital-to-analog conversion component converts the analog quantity into a current optical signal and transmits it to the merging unit through the signal transmission component; the voltage transformer transmits the obtained voltage optical signal to the merging unit.

[0005] Further, the insulation support structure is a composite bushing, and the composite bushing includes a fiberglass barrel and silicone rubber umbrella skirts arranged on the outer side of the fiberglass barrel; the signal transmission component is a plurality of optical fibers, one ends of the plurality of optical fibers are connected to the current transformer, the other ends are connected to the merging unit, and the plurality of optical fibers are arranged in a cross double helix manner between the fiberglass barrel and the silicone rubber umbrella skirts.

[0006] Further, the digital-to-analog conversion component is connected to a non-magnetically saturated Rogowski coil and is connected to a plurality of optical fibers. The non-magnetically saturated Rogowski coil is used to measure the primary current of the high-voltage combined electronic current transformer and convert it into an analog quantity, and then transmit it to the digital-to-analog conversion component; the digital-to-analog conversion component is used to receive and convert the analog quantity into an optical current signal and transmit it to the plurality of optical fibers; the plurality of optical fibers are used to receive the optical current signal and transmit it to the merging unit.

[0007] Further, the current transformer further includes a power supply module, and the digital-to-analog conversion component is connected to the power supply module. When the power line where the high-voltage combined electronic current transformer is located is in an operating state, the power supply module takes power from the capacitor on the coupling capacitor and transmits it to the digital-to-analog conversion component to achieve power supply; when the power line where the high-voltage combined electronic current transformer is located is in a power-off state, the power supply module transmits the laser at the bottom of the high-voltage combined electronic current transformer to the digital-to-analog conversion component through the plurality of optical fibers to achieve power supply.

[0008] Further, when the power line where the high-voltage combined electronic current transformer is located is in an operating state, the power supply module includes a transmission bushing and a power line arranged in the transmission bushing. The transmission bushing is installed on the top plate of the composite bushing, one end of the power line is connected to the digital-to-analog conversion component, and the other end is connected to the capacitor on the coupling capacitor.

[0009] Further, the current transformer further includes a housing, and grading rings are arranged at the upper and lower ends of the housing; the digital-to-analog conversion component is a circuit board, a circuit board shielding box and a shielding cover are arranged in the housing, the circuit board is arranged in the circuit board shielding box, the non-magnetically saturated Rogowski coil is arranged in the shielding cover, and the circuit board is connected to the non-magnetically saturated Rogowski coil.

[0010] Further, high-purity nitrogen is arranged inside the coupling capacitor and the voltage-dividing capacitor.

[0011] Further, the voltage transformer further includes a signal acquisition component and an oil tank disposed at the bottom. An optoelectronic conversion module is disposed in the oil tank and is configured to convert the voltage analog signal acquired by the signal acquisition component into a voltage optical signal. An uninterruptible power supply and a laser converter are disposed inside the oil tank. When the power line where the high-voltage combined electronic transformer is located is in a power-off state, the uninterruptible power supply is used to supply power to the voltage transformer, and the power supply module transmits the laser emitted by the laser converter to the analog-to-digital conversion component of the current transformer through multiple optical fibers to achieve power supply.

[0012] Further, shielding rings are provided between the coupling capacitors and between the coupling capacitor and the voltage-dividing capacitor. Multiple optical fibers between the coupling capacitors and between the coupling capacitor and the voltage-dividing capacitor are connected by aerospace-grade optical fiber plugs and are placed inside the shielding rings between the coupling capacitors and between the coupling capacitor and the voltage-dividing capacitor.

[0013] The present invention also provides a method for using a high-voltage combined electronic transformer. The technical solution adopted is as follows: A method for using a high-voltage combined electronic transformer, based on the above-mentioned high-voltage combined electronic transformer, includes the following steps: The non-magnetically saturated Rogowski coil in the current transformer measures the primary current of the high-voltage combined electronic transformer and converts the primary current into an analog quantity. The analog-to-digital conversion component converts the analog quantity into a current optical signal and transmits the current optical signal to the merging unit through the signal transmission component. The high voltage passes through a voltage transformer composed of at least one coupling capacitor and one voltage-dividing capacitor stacked in sequence to achieve low-voltage output, and transmits the output low-voltage voltage optical signal to the merging unit.

[0014] Compared with the prior art, the present application has the following beneficial effects: The present invention is an improved invention, which provides a novel high-voltage combined electronic transformer. By setting the combination of a current transformer and a voltage transformer, it can obtain current optical signals and voltage optical signals simultaneously, and can replace traditional independent current transformers and independent voltage transformers in the power system. At the same time, through at least one coupling capacitor and one voltage-dividing capacitor stacked in sequence, the high voltage is gradually stepped down to obtain the final voltage division. Through the insulating support structure arranged on the outer side of each coupling capacitor and voltage-dividing capacitor, the insulation and support between the coupling capacitor and the current transformer, between the coupling capacitors, and between the coupling capacitor and the voltage-dividing capacitor are realized, and the insulation structure is simple. The current transformer of the high-voltage combined electronic transformer of the present invention uses a Rogowski coil without magnetic saturation with multiple taps to measure the primary current of the high-voltage combined electronic transformer and converts the primary current into an analog quantity. Utilizing the non-magnetic saturation characteristic of the Rogowski coil solves the problem of magnetic saturation of traditional transformers, avoids the problems of magnetic saturation, open circuit, and explosion danger of current transformers, as well as ferroresonance and short circuit of voltage transformers. Moreover, the multiple taps of the Rogowski coil without magnetic saturation can achieve full coverage of the measurement of the primary current of the existing power grid, with high standardization, realizing the accurate measurement of current data and voltage data, and improving the reliability of power grid operation.

[0015] Compared with traditional transformers, the high-voltage combined electronic transformer of the present invention has the following advantages: (1) The current transformer is arranged at the top position of the high-voltage combined electronic transformer, that is, installed on the upper part of the coupling part of the voltage transformer, reducing the floor area. (2) The voltage transformer has no inductive elements, avoiding the generation of ferroresonance; by changing the number of coupling capacitors, voltage measurement under various voltage systems can be realized. (3) The output quantities of the current transformer and the voltage transformer are digital quantities, enabling the digitization and intellectualization of the power system.

[0016] The insulating support structure is a composite bushing, and the composite bushing includes a fiberglass barrel and silicone rubber umbrella skirts arranged on the outer side of the fiberglass barrel; the signal transmission component is multiple optical fibers. One end of the multiple optical fibers is connected to the current transformer, and the other end is connected to the merging unit, and the multiple optical fibers are arranged in a cross double helix between the fiberglass barrel and the silicone rubber umbrella skirts. In this structure, composite bushing insulation is used, with strong anti-fouling flashover ability; at the same time, the cross double helix arrangement of multiple optical fibers can eliminate the interference of the electric fields of the coupling capacitors and voltage-dividing capacitors in the composite bushing on the signals of the optical fibers.

[0017] The current transformer further includes a power supply module. The digital-to-analog conversion component is connected to the power supply module. When the power line where the high-voltage combined electronic current transformer is located is in an operating state, the power supply module draws power from the capacitance of the coupling capacitor and transmits it to the digital-to-analog conversion component to achieve power supply. When the power line where the high-voltage combined electronic current transformer is located is in a power-off state, the power supply module transmits the laser at the bottom of the high-voltage combined electronic current transformer to the digital-to-analog conversion component through multiple optical fibers to achieve power supply. This structure adopts an oil-free design, avoiding the explosion risk of traditional oil transformers and not requiring sulfur hexafluoride gas, making it more environmentally friendly.

[0018] The current transformer further includes a housing. Voltage equalizing rings are provided at the upper and lower ends of the housing. The digital-to-analog conversion component is a circuit board. A circuit board shielding box and a shielding cover are provided inside the housing. The circuit board is arranged in the circuit board shielding box, and the non-magnetically saturated Rogowski coil is arranged inside the shielding cover, and the circuit board is connected to the non-magnetically saturated Rogowski coil. In this structure, voltage equalizing rings are provided at the upper and lower ends of the housing, which can reduce the radio interference level.

[0019] High-purity nitrogen is provided inside the coupling capacitor and the voltage dividing capacitor. This structure adopts an oil-free design, with high-purity nitrogen filled inside as internal insulation to achieve an oil-free design and avoid the oil leakage problem of traditional transformers. Brief Description of the Drawings

[0020] Figure 1 is the main structural view of the high-voltage combined electronic current transformer of the present invention; Figure 2 is the right structural view of the high-voltage combined electronic current transformer of the present invention; Figure 3 is the structural schematic diagram of the current transformer in the high-voltage combined electronic current transformer of the present invention; Figure 4 is the structural schematic diagram of the connection between the coupling capacitor and the coupling capacitor in the high-voltage combined electronic current transformer of the present invention; In the figure, 1. Current transformer; 2. Coupling capacitor; 3. Voltage dividing capacitor; 4. Fiberglass barrel; 5. Silicone rubber umbrella skirt; 6. Optical fiber; 7. Non-magnetically saturated Rogowski coil; 8. Transmission sleeve; 9. Power cord; 10. Housing; 11. Circuit board shielding box, 12. Circuit board; 13. Shielding cover; 14. Primary winding; 15. Voltage equalizing ring; 16. Photoelectric conversion module; 17. Shielding ring; 18. Optical fiber plug; 19. Secondary terminal box; 20. Hoisting hole; 21. Grounding plate. Detailed Description of the Invention

[0021] As cited in the background art, the stability of extra-high voltage capacitive voltage transformers in the prior art is insufficient, and current transformers have problems such as magnetic saturation and large floor space. Therefore, the present invention provides a high-voltage combined electronic transformer, comprising: a current transformer 1, a voltage transformer, an insulating support structure, and a merging unit. The current transformer 1 obtains current optical signals; the voltage transformer obtains voltage optical signals; the voltage transformer includes at least one coupling capacitor 2 and a voltage-dividing capacitor 3 stacked in sequence to gradually reduce the high voltage and obtain the final voltage division; the current transformer 1 is arranged at the top position of the high-voltage combined electronic transformer and is connected to the coupling capacitor 2 at the top of the voltage transformer, and the voltage-dividing capacitor 3 is arranged at the lower end of the voltage transformer; the insulating support structure is arranged outside each coupling capacitor 2 and voltage-dividing capacitor 3 to achieve insulation and support between the coupling capacitor 2 and the current transformer 1, between the coupling capacitor 2 and the coupling capacitor 2, and between the coupling capacitor 2 and the voltage-dividing capacitor 3; and a signal transmission component connected to the current transformer 1 is arranged inside it for transmitting current optical signals; the current transformer 1 includes a non-magnetically saturated Rogowski coil 7 with multiple taps and a digital-to-analog conversion component. The non-magnetically saturated Rogowski coil 7 is used to measure the primary current of the high-voltage combined electronic transformer and convert the primary current into an analog quantity, and the digital-to-analog conversion component converts the analog quantity into a current optical signal and transmits it to the merging unit through the signal transmission component, avoiding problems such as magnetic saturation, open circuit, and explosion hazards, as well as ferroresonance and short circuit of the voltage transformer; and the multiple taps of the non-magnetically saturated Rogowski coil 7 can achieve full coverage of the measurement of the primary current of the existing power grid, with high standardization; the voltage transformer transmits the obtained voltage optical signal to the merging unit. The high-voltage combined electronic transformer of the present invention realizes accurate measurement of current data and voltage data, and improves the reliability of power grid operation.

[0022] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application and should not be construed as limiting the present application.

[0023] It should be noted that the terms "first", "second", etc. in the description, claims and the above-mentioned drawings of the present invention are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0024] Specific Embodiment 1 of the high-voltage combined electronic current transformer of the present invention: In this embodiment, as Figure 1 、 Figure 2 and Figure 3 shown, the high-voltage combined electronic current transformer includes: a current transformer 1, a voltage transformer, an insulating support structure and a merging unit. The voltage transformer includes two coupling capacitors 2 stacked in sequence and a voltage dividing capacitor 3. The current transformer 1 is arranged at the top position of the high-voltage combined electronic current transformer and is connected to the coupling capacitor 2 at the top of the voltage transformer. The voltage dividing capacitor 3 is arranged at the lower end of the voltage transformer. The insulating support structure is arranged outside each coupling capacitor 2 and the voltage dividing capacitor 3, and a signal transmission component connected to the current transformer 1 is arranged inside it; the current transformer 1 includes a non-magnetically saturated Rogowski coil 7 with multiple taps and a digital-to-analog conversion component. The non-magnetically saturated Rogowski coil 7 is used to measure the primary current of the high-voltage combined electronic current transformer and convert the primary current into an analog quantity. The digital-to-analog conversion component converts the analog quantity into a current optical signal and transmits it to the merging unit through the signal transmission component. The voltage transformer transmits the obtained voltage optical signal to the merging unit. Among them, the non-magnetically saturated Rogowski coil 7 has multiple taps, that is, multiple output terminals, and can accurately measure any primary current. A lifting member is installed at the bottom of the high-voltage combined electronic current transformer, and a lifting hole 20 is provided on the lifting member for the transportation of the high-voltage combined electronic current transformer.

[0025] Specifically, the insulating support structure is a composite bushing. The composite bushing includes a fiberglass barrel 4 and a silicone rubber umbrella skirt 5 arranged outside the fiberglass barrel 4; the signal transmission component is multiple optical fibers 6. One ends of the multiple optical fibers 6 are connected to the current transformer 1, and the other ends are connected to the merging unit, and the multiple optical fibers 6 are arranged in a cross double helix between the fiberglass barrel 4 and the silicone rubber umbrella skirt 5. Among them, the composite bushing is used for insulation and support and has strong anti-fouling flashover ability; the multiple optical fibers 6 are arranged in a cross double helix structure, which can eliminate the interference of the electric fields of the coupling capacitor 2 and the voltage dividing capacitor 3 in the bushing on the signals of the optical fibers 6.

[0026] The digital-to-analog conversion component is connected to the non-magnetically saturated Rogowski coil 7 and is connected to multiple optical fibers 6. The non-magnetically saturated Rogowski coil 7 is used to measure the primary current of the high-voltage combined electronic current transformer and convert it into an analog quantity, and then transmit it to the digital-to-analog conversion component; the digital-to-analog conversion component is used to receive and convert the analog quantity into a current optical signal and transmit it to multiple optical fibers 6, and the multiple optical fibers 6 are used to receive the current optical signal and transmit it to the merging unit to achieve isolation between high voltage and low voltage.

[0027] In other embodiments, the voltage transformer includes a coupling capacitor 2 and a voltage-dividing capacitor 3 stacked in sequence.

[0028] In other embodiments, the voltage transformer includes three coupling capacitors 2 and a voltage-dividing capacitor 3 stacked in sequence.

[0029] Specific embodiment 2 of the high-voltage combined electronic current transformer of the present invention: Based on the above technical concept of the present invention, or based on the specific embodiments of the present invention introduced above, another embodiment is provided below.

[0030] In this embodiment, as Figure 1 、 Figure 2 and Figure 3 shown, the current transformer 1 further includes a power supply module. The digital-to-analog conversion component is connected to the power supply module. When the power line where the high-voltage combined electronic current transformer is located is in an operating state, the power supply module takes power from the capacitor on the coupling capacitor 2 and transmits it to the digital-to-analog conversion component to achieve power supply; when the power line where the high-voltage combined electronic current transformer is located is in a power-off state, the power supply module transmits the laser at the bottom of the high-voltage combined electronic current transformer to the digital-to-analog conversion component through multiple optical fibers 6 to achieve power supply. Among them, when the power line where the high-voltage combined electronic current transformer is located is in an operating state, the power supply module includes a transmission bushing 8 and a power line 9 arranged in the transmission bushing 8. The transmission bushing 8 is installed on the top plate of the composite bushing, one end of the power line 9 is connected to the digital-to-analog conversion component, and the other end is connected to the capacitor on the coupling capacitor 2. The current transformer 1 further includes a housing 10, and grading rings 15 are arranged at the upper and lower ends of the housing 10; the digital-to-analog conversion component is a circuit board 12, a circuit board shielding box 11 and a shielding cover 13 are arranged in the housing 10, the circuit board 12 is arranged in the circuit board shielding box 11, the non-magnetically saturated Rogowski coil 7 is arranged in the shielding cover 13, and the circuit board 12 is connected to the non-magnetically saturated Rogowski coil 7.

[0031] Specifically, the Rogowski coil 7 without magnetic saturation measures the primary current of the high-voltage combined electronic current transformer, converts the primary current into an analog quantity and outputs it to the circuit board 12. The circuit board 12 receives the analog quantity and converts it into a current optical signal, and the current optical signal is finally transmitted to the bottom of the product, i.e., the merging unit, through multiple optical fibers 6. When the power line where the high-voltage combined electronic current transformer is located is in the operating state, the power supply module takes power on the capacitor of the coupling capacitor 2 and transmits it to the power supply module of the circuit board 12, converting the alternating current into direct current to supply power to the circuit board 12; when the power line where the high-voltage combined electronic current transformer is located is in the power-off state, the power supply module transmits the laser at the bottom of the high-voltage combined electronic current transformer to the circuit board 12 through multiple optical fibers 6 and converts it into direct current to realize the power supply to the circuit board 12.

[0032] In other embodiments, the current transformer 1 can also adopt an all-fiber structure. Multiple optical fibers 6 are wound around the primary winding 14 as the center inside the shielding housing 13. Through the principle of the Faraday magneto-optical effect, the current measurement function can be realized.

[0033] Specific embodiment 3 of the high-voltage combined electronic current transformer of the present invention: Based on the above technical concept of the present invention, or on the basis of the specific embodiments of the present invention introduced above, another embodiment is provided below.

[0034] In this embodiment, as Figure 1 、 Figure 2 、 Figure 3 and Figure 4As shown in the figure, high-purity nitrogen gas is provided inside the coupling capacitor 2 and the voltage-dividing capacitor 3. The coupling capacitor 2 and the voltage-dividing capacitor 3 adopt an oil-free design, and are filled with high-purity nitrogen gas as internal insulation to achieve the oil-free design and avoid the oil leakage problem of traditional transformers. The voltage transformer further includes a signal acquisition component and an oil tank arranged at the bottom. An optoelectronic conversion module 16 is arranged in the oil tank and is used to convert the voltage analog signal collected by the signal acquisition component into a voltage optical signal. Since the oil tank is at the low potential at the lower part of the product, its optoelectronic conversion module 16 can be powered by the commercial power supply. Specifically, through the cooperation of the coupling capacitor 2 and the voltage-dividing capacitor 3, the high voltage on the high-voltage side is stepped down and divided by the coupling capacitor 2 and the voltage-dividing capacitor 3, and then led out from the middle-voltage bushing of the voltage-dividing capacitor 3 to the oil tank part at the lower part of the high-voltage combined electronic transformer, and is converted into a voltage optical signal through the optoelectronic conversion module 16 inside the oil tank and output. An uninterruptible power supply and a laser converter are arranged inside the oil tank. When the power line where the high-voltage combined electronic transformer is located is in a power-off state, the uninterruptible power supply is used to supply power to the voltage transformer; the power supply module transmits the laser emitted by the laser converter to the digital-to-analog conversion component of the current transformer 1 through multiple optical fibers 6 to achieve power supply. Among them, the laser converter is arranged inside the oil tank; a secondary terminal box 19 is provided on one side of the oil tank, which serves as the outlet of the oil tank. Multiple optical fibers 6 are led out from the secondary terminal box 19 and connected to the merging unit; a grounding plate 21 is arranged on one side of the oil tank and is used for grounding the high-voltage combined electronic transformer. A shielding ring 17 is arranged between the coupling capacitor 2 and the coupling capacitor 2, and between the coupling capacitor 2 and the voltage-dividing capacitor 3. Multiple optical fibers 6 between the coupling capacitor 2 and the coupling capacitor 2, and between the coupling capacitor 2 and the voltage-dividing capacitor 3 are connected by aviation-grade optical fiber plugs 18 and are placed inside the shielding ring 17 between the coupling capacitor 2 and the coupling capacitor 2, and between the coupling capacitor 2 and the voltage-dividing capacitor 3.

[0035] Specific embodiment 1 of the usage method of the high-voltage combined electronic transformer of the present invention: The present application also provides a usage method of a high-voltage combined electronic transformer. Based on the above high-voltage combined electronic transformer, it includes the following steps: The non-magnetically saturated Rogowski coil 7 in the current transformer 1 measures the primary current of the high-voltage combined electronic transformer and converts the primary current into an analog quantity. The digital-to-analog conversion component converts the analog quantity into a current optical signal and transmits the current optical signal to the merging unit through the signal transmission component; the high voltage passes through a voltage transformer composed of at least one coupling capacitor 2 and one voltage-dividing capacitor 3 stacked in sequence to achieve low-voltage output, and transmits the output low-voltage voltage optical signal to the merging unit.

[0036] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. The scope of patent protection of the present invention is subject to the claims. Any equivalent structural changes made by using the description and drawings of the present invention shall equally be included in the protection scope of the present invention.

Claims

1. A high-voltage combined electronic current transformer, characterized in that Comprising: A current transformer (1), a voltage transformer, an insulating support structure, and a merging unit. The voltage transformer includes at least one coupling capacitor (2) and a voltage-dividing capacitor (3) stacked in sequence. The current transformer (1) is arranged at the top position of the high-voltage combined electronic transformer and is connected to the coupling capacitor (2) at the top of the voltage transformer. The voltage-dividing capacitor (3) is arranged at the lower end of the voltage transformer. The insulating support structure is arranged outside each coupling capacitor (2) and voltage-dividing capacitor (3), and a signal transmission component connected to the current transformer (1) is arranged inside it. The current transformer (1) includes a non-magnetically saturated Rogowski coil (7) with multiple taps and a digital-to-analog conversion component. The non-magnetically saturated Rogowski coil (7) is used to measure the primary current of the high-voltage combined electronic transformer and convert the primary current into an analog quantity. The digital-to-analog conversion component converts the analog quantity into a current optical signal and transmits it to the merging unit through the signal transmission component. The voltage transformer transmits the obtained voltage optical signal to the merging unit.

2. The high-voltage combined electronic current transformer according to claim 1, wherein The insulating support structure is a composite bushing, and the composite bushing includes a fiberglass barrel (4) and a silicone rubber umbrella skirt (5) arranged outside the fiberglass barrel (4). The signal transmission component is multiple optical fibers (6). One ends of the multiple optical fibers (6) are connected to the current transformer (1), and the other ends are connected to the merging unit. The multiple optical fibers (6) are arranged in a cross double helix between the fiberglass barrel (4) and the silicone rubber umbrella skirt (5).

3. The high-voltage combined electronic current transformer according to claim 2, characterized in that, The digital-to-analog conversion component is connected to the non-magnetically saturated Rogowski coil (7) and connected to multiple optical fibers (6). After the non-magnetically saturated Rogowski coil (7) measures the primary current of the high-voltage combined electronic transformer and converts it into an analog quantity, it transmits the analog quantity to the digital-to-analog conversion component. The digital-to-analog conversion component is used to receive and convert the analog quantity into a current optical signal and transmit it to the multiple optical fibers (6). The multiple optical fibers (6) are used to receive the current optical signal and transmit it to the merging unit.

4. The high-voltage combined electronic transformer according to claim 3, characterized in that, The current transformer (1) further includes a power supply module. The digital-to-analog conversion component is connected to the power supply module. When the power line where the high-voltage combined electronic transformer is located is in an operating state, the power supply module takes power from the capacitance on the coupling capacitor (2) and transmits it to the digital-to-analog conversion component to achieve power supply. When the power line where the high-voltage combined electronic transformer is located is in a power-off state, the power supply module transmits the laser at the bottom of the high-voltage combined electronic transformer to the digital-to-analog conversion component through the multiple optical fibers (6) to achieve power supply.

5. The high-voltage combined electronic current transformer according to claim 4, wherein When the power line where the high-voltage combined electronic transformer is located is in an operating state, the power supply module includes a transmission bushing (8) and a power line (9) arranged in the transmission bushing (8). The transmission bushing (8) is installed on the top plate of the composite bushing. One end of the power line (9) is connected to the digital-to-analog conversion component, and the other end is connected to the capacitance on the coupling capacitor (2).

6. The high-voltage combined electronic current transformer according to claim 5, wherein, The current transformer (1) further includes a housing (10), and grading rings (15) are arranged at the upper and lower ends of the housing (10); the digital-to-analog conversion component is a circuit board (12), a circuit board shielding box (11) and a shielding cover (13) are arranged in the housing (10), the circuit board (12) is arranged in the circuit board shielding box (11), the non-magnetically saturated Rogowski coil (7) is arranged in the shielding cover (13), and the circuit board (12) is connected to the non-magnetically saturated Rogowski coil (7).

7. The high-voltage combined electronic current transformer according to claim 4, characterized in that, High-purity nitrogen is arranged inside the coupling capacitor (2) and the voltage dividing capacitor (3).

8. The high-voltage combined electronic current transformer according to claim 7, characterized in that, The voltage transformer further includes a signal acquisition component and an oil tank arranged at the bottom, and an optoelectronic conversion module (16) is arranged in the oil tank for converting the voltage analog signal acquired by the signal acquisition component into a voltage optical signal; an uninterruptible power supply and a laser converter are arranged inside the oil tank. When the power line where the high-voltage combined electronic type transformer is located is in a power-off state, the uninterruptible power supply is used to supply power to the voltage transformer, and the power supply module transmits the laser emitted by the laser converter to the digital-to-analog conversion component in the current transformer (1) through multiple optical fibers (6) to achieve power supply.

9. The high-voltage combined electronic current transformer according to claim 8, characterized in that, Shielding rings (17) are arranged between the coupling capacitors (2) and between the coupling capacitor (2) and the voltage dividing capacitor (3). Multiple optical fibers (6) between the coupling capacitors (2) and between the coupling capacitor (2) and the voltage dividing capacitor (3) are connected by aviation-grade optical fiber plugs (18) and are placed inside the shielding rings (17) between the coupling capacitors (2) and between the coupling capacitor (2) and the voltage dividing capacitor (3).

10. A method for using a high-voltage combined electronic current transformer, characterized in that, Based on the high-voltage combined electronic type transformer according to any one of claims 1-9, the following steps are included: The non-magnetically saturated Rogowski coil (7) in the current transformer (1) tests the primary current of the high-voltage combined electronic type transformer and converts the primary current into an analog quantity. The digital-to-analog conversion component converts the analog quantity into a current optical signal and transmits the current optical signal to the merging unit through the signal transmission component; the high voltage passes through a voltage transformer composed of at least one coupling capacitor (2) and one voltage dividing capacitor (3) stacked in sequence to achieve low-voltage output, and transmits the output low-voltage voltage optical signal to the merging unit.

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