High-voltage sensor, high-voltage electric appliance, high-voltage bushing, high-voltage monitoring system

Abstract

The application relates to the field of high-voltage electrical apparatus, and relates to a high-voltage sensor, a high-voltage electrical apparatus, a high-voltage bushing and a high-voltage monitoring system. The high-voltage sensor comprises an insulating core body, a plurality of capacitor screens are arranged in the insulating core body in an alternating manner with insulating layers, the capacitor screens comprise a plurality of voltage-sharing capacitor screens for realizing high-voltage insulation, and an optical fiber is arranged in the insulating core body. The optical fiber is wound into a plurality of turns to form an optical fiber coil. The optical fiber coil is connected with a first lead-out wire and extends out of the insulating core body, and is used as a current sensor. The small-sized and solidified insulating core body can protect the optical fiber from being damaged, and the optical fiber can be closer to a conductor coated by the insulating core body, so that the strength of collected signals is improved. The high-voltage electrical apparatus and the high-voltage bushing comprise the high-voltage sensor. The high-voltage monitoring system comprises the high-voltage electrical apparatus and a monitoring device connected with the high-voltage electrical apparatus.

Description

Technical Field

[0001] This invention relates to the field of high-voltage electrical appliances, and specifically to a high-voltage sensor, high-voltage electrical appliance, and high-voltage monitoring system based on a capacitive insulating core. Background Technology

[0002] Existing high-voltage electrical equipment includes bushings, cable terminals, voltage transformers, current transformers, disconnect switches, circuit breakers, surge arresters, and insulators. Insulation protection is achieved through a capacitive insulating core. Multiple voltage-equalizing capacitors, alternately arranged around the insulating layer, gradually divide the high voltage to ground potential, thus achieving insulation protection. Further, voltage-dividing capacitors are wound within the insulating core. The voltage-equalizing capacitors form voltage-equalizing capacitor C1, and the voltage-dividing capacitors form voltage-dividing capacitor C2. Voltage-equalizing capacitor C1 and voltage-dividing capacitor C2 are connected in series to form a capacitive voltage divider, further forming a voltage transformer (this type of low-power voltage transformer is also called VT). This type of voltage transformer VT has low power consumption and high safety, thus constituting a high-voltage sensor that can function as a voltage transformer to collect voltage signals. In addition, existing technologies typically also include an air-core coil surrounding the insulating core, which can function as a current transformer to collect current signals, increasing the size of the high-voltage electrical equipment.

[0003] Furthermore, insulating oil in transformers is essential for their normal operation. It not only provides insulation but also acts as a coolant, preventing the transformer from operating in high-temperature environments. If the transformer system malfunctions, its internal temperature rises, and the temperature of the insulating oil itself will increase accordingly. If not addressed promptly, this will affect the safe operation and lifespan of the transformer. Therefore, existing technologies incorporate temperature detection devices to monitor the temperature of the insulating oil. Detection methods involving direct contact with the insulating oil offer high reliability and are popular with users. These contact-type temperature detection devices can employ various temperature sensors, including mercury thermometers, resistance temperature sensors, pressure thermometers, semiconductor digital temperature sensors, and fiber optic temperature sensors. However, these require separate drilling and installation on the transformer, increasing construction difficulty and cost.

[0004] Furthermore, online oil chromatography monitoring of transformers is an important means of digital and intelligent management of key equipment such as oil-immersed transformers or reactors. It can be used to monitor whether there are latent overheating, discharge, or other faults in the transformer, thus ensuring the safe and efficient operation of the power grid. It is a fundamental technology for realizing state perception, analysis and diagnosis, state prediction, and decision-making. However, existing oil chromatography monitoring requires the installation of a separate oil circuit and connection to the oil chromatography monitoring equipment, which is not only cumbersome to construct but also costly. Summary of the Invention

[0005] The purpose of this invention is to overcome at least one defect of the prior art and provide a high-voltage sensor, a high-voltage electrical appliance, and a high-voltage monitoring system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A high-voltage sensor includes an insulating core, within which are arranged multiple capacitive screens alternately surrounding an insulating layer. Each capacitive screen includes multiple voltage-equalizing capacitive screens for achieving high-voltage insulation. An optical fiber is also provided within the insulating core, the optical fiber being wound with multiple turns to form an optical fiber loop. A first lead wire extends from the optical fiber loop to the outside of the insulating core and is used as a current sensor.

[0008] Furthermore, the optical fiber is wound on any one of the insulating layers within the insulating core.

[0009] Furthermore, the optical fiber is wound on the insulating layer between two adjacent capacitor screens of the insulating core, or the optical fiber is wound on the insulating layer outside all the capacitor screens, and an insulating layer is set outside the optical fiber to form an integral insulating core.

[0010] Furthermore, the plurality of capacitive screens include a voltage equalizing capacitor screen forming a voltage equalizing capacitor and a voltage dividing capacitor screen forming a voltage dividing capacitor. The voltage equalizing capacitor and the voltage dividing capacitor are connected in series to form a capacitive voltage divider. A second signal line is connected between the voltage equalizing capacitor and the voltage dividing capacitor and extends out of the insulating core body.

[0011] Furthermore, the plurality of capacitive screens also include a plurality of shielded capacitive screens forming a shielded anti-interference capacitor. The plurality of shielded capacitive screens are alternately arranged with the insulating layer and at least surround a portion of the voltage equalizing capacitive screen, for shielding external interference signals.

[0012] Furthermore, the plurality of capacitive screens also include an insulating information capacitor screen forming an insulating information acquisition capacitor. The insulating information acquisition capacitor is wound around the outside of the shielding anti-interference capacitor. The insulating information acquisition capacitor and the shielding anti-interference capacitor are connected in series. A third lead is connected between the shielding anti-interference capacitor and the insulating information acquisition capacitor and extends out of the insulating core body. Alternatively, the insulating information acquisition capacitor is located between the equalizing capacitor and the dividing capacitor. The insulating information acquisition capacitor is connected in series between the equalizing capacitor and the dividing capacitor. The series-connected equalizing capacitor, the insulating information acquisition capacitor, and the dividing capacitor are connected in parallel with the shielding anti-interference capacitor. The third lead is led out from between the equalizing capacitor and the insulating information acquisition capacitor and extends out of the insulating core body.

[0013] Furthermore, a λ / 4 waveplate and a reflector are also provided inside the insulating core, and the λ / 4 waveplate and the reflector are connected to both ends of the fiber coil.

[0014] Furthermore, one end of the fiber optic loop is a fiber grating, and the other end extends out as the first lead; or, two first leads extend from both ends of the fiber optic loop.

[0015] Furthermore, an oil chromatography detection fiber and an oil temperature detection fiber are also installed inside the insulating core.

[0016] Furthermore, the insulating core uses epoxy resin-impregnated glass fiber as the insulating layer, semiconducting or metal strips as the capacitor screen, and the optical fiber is a sensing optical fiber; the optical fiber is wound on the insulating layer on the outside of all the capacitor screens, and the optical fiber is covered by the insulating layer.

[0017] The present invention also provides a high-voltage electrical appliance, which includes a high-voltage sensor according to any of the above-described embodiments.

[0018] Furthermore, the high-voltage electrical appliance is any one of bushings, cable terminals, current transformers, disconnect switches, circuit breakers, surge arresters, and insulators.

[0019] The present invention also provides a high-voltage bushing, wherein the high-voltage bushing includes a high-voltage sensor according to any of the above-described embodiments.

[0020] The present invention also provides a high-voltage monitoring system, including the aforementioned high-voltage electrical appliance and a monitoring device connected to the high-voltage electrical appliance.

[0021] This invention creates a high-voltage sensor based on a capacitive insulating core, in which an optical fiber is directly embedded within the insulating core, forming an integrated high-voltage sensor capable of acquiring current signals. It offers the following advantages: First, it eliminates the need for an external hollow coil, reducing the sensor's size; second, the solidified insulating core protects the optical fiber from damage and displacement; and third, the optical fiber can be positioned closer to the conductor encased in the insulating core, improving the strength of the acquired signal.

[0022] High-voltage electrical appliances employing the aforementioned anti-interference structure with insulating cores include bushings, cable terminals, current transformers, disconnect switches, circuit breakers, surge arresters, and insulators, integrating the function of current transformers and featuring a small device size.

[0023] Furthermore, this invention creates a high-voltage bushing based on a capacitive insulating core, in which an oil temperature detection fiber and / or an oil chromatography detection fiber are directly embedded within the insulating core for monitoring oil temperature and performing oil chromatography detection. This allows the high-voltage bushing to not only function as a bushing but also to perform oil temperature detection and / or oil chromatography detection functions. It eliminates the need for separate openings for oil temperature detection and oil chromatography detection, and the solidified insulating core protects the oil temperature detection fiber and / or oil chromatography detection fiber from damage, eliminating the need for additional high-voltage isolation structures and protective housings.

[0024] In addition, a hollow protective tube is provided outside the second monitoring end of the oil temperature detection optical fiber and / or the first monitoring end of the oil chromatography detection optical fiber, which can protect the first monitoring end and the second monitoring end, and the insulating oil can also enter the protective tube.

[0025] Furthermore, the protective tube is not only hollow in the axial direction, but also has multiple small holes in the radial direction, which allows the insulating oil to flow and improves the reliability of the test results, rather than continuously testing the insulating oil in a fixed part. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the multifunctional high-voltage sensor based on the insulating sleeve in Embodiment 1. It shows a partial cross-sectional view of the insulating core of the insulating sleeve, wherein the right half shows a schematic diagram of the internally wound capacitor screen, and the left half shows a schematic diagram of the optical fiber.

[0027] Figure 2 yes Figure 1 Enlarged view of section A;

[0028] Figure 3 This is the electrical schematic diagram of the voltage equalizing capacitor C1, voltage dividing capacitor C2, and shielding anti-interference capacitor C3, which are composed of capacitor screens inside the insulating core.

[0029] Figure 4 This is the electrical schematic diagram of Embodiment 1 of the voltage equalizing capacitor C1, voltage dividing capacitor C2, shielding anti-interference capacitor C3, and insulation information acquisition capacitor C4, which are composed of a capacitor screen inside the insulating core.

[0030] Figure 5 This is the electrical schematic diagram of Embodiment 2, which shows the relationship between the equalizing capacitor C1, the voltage dividing capacitor C2, the shielding and anti-interference capacitor C3, and the insulating information acquisition capacitor C4, which are composed of a capacitor screen inside the insulating core.

[0031] Figure 6 This is a schematic block diagram of an embodiment of an optical fiber current transformer;

[0032] Figure 7 This is a schematic diagram of the structure of the multifunctional high-voltage sensor based on the insulating bushing in Embodiment 2, showing a partial cross-sectional view of the insulating core of the insulating bushing.

[0033] Figure 8 yes Figure 7 An enlarged view of part B;

[0034] Figure 9 This is a schematic diagram of an embodiment of a laser oil chromatography sensor;

[0035] Figure 10 This is an example of an optical fiber temperature sensor. Detailed Implementation

[0036] The specific embodiments of the present invention are further described below with reference to the accompanying drawings. The present invention is not limited to the descriptions of the following embodiments.

[0037] like Figure 1 As shown, the present invention provides a high-voltage sensor that can be used in the capacitive insulating core of various high-voltage electrical appliances. The insulating core 10 has multiple capacitive screens arranged alternately around the insulating layer. The capacitive screens include multiple voltage-equalizing capacitive screens 101 for achieving high-voltage insulation. The voltage-equalizing capacitive screens 101 gradually equalize and reduce the high potential inside the insulating core to the low potential outside, until it reaches the ground potential.

[0038] Furthermore, the plurality of equalizing capacitor screens 101 constitute an equalizing capacitor C1. The capacitor screen also includes a plurality of voltage dividing capacitor screens 102 surrounding the equalizing capacitor C1. The plurality of voltage dividing capacitor screens 102 are alternately wound with an insulating layer, and the plurality of voltage dividing capacitor screens 102 constitute a voltage dividing capacitor C2. The equalizing capacitor C1 and the voltage dividing capacitor C2 are connected in series to form a capacitor voltage divider. A second signal line is connected between the equalizing capacitor C1 and the voltage dividing capacitor C2 and extends to the outside of the insulating core 10 to realize the function of a voltage transformer, to collect voltage signals, and can also be used for harmonic detection.

[0039] Furthermore, the capacitor screen also includes multiple shielding capacitor screens 103 surrounding the equalizing capacitor C1. These shielding capacitor screens 103, alternately arranged with an insulating layer, constitute a shielding anti-interference capacitor C3 for shielding external interference signals. The multiple shielding capacitor screens 103 at least partially surround the equalizing capacitor screen 101 to improve the accuracy of the voltage transformer's signal acquisition. The electrical schematic diagram of the equalizing capacitor C1, the voltage dividing capacitor C2, and the shielding anti-interference capacitor C3 can be found in [reference needed]. Figure 3 .

[0040] Furthermore, an insulation information capacitor screen 104 can also be provided inside the insulating core 10. That is, the multiple capacitor screens within the insulating core 10 also include the insulation information capacitor screen 104 forming the insulation information acquisition capacitor C4. A third lead extends from the insulation information capacitor screen 104 to the outside of the insulating core 10, used for online monitoring of the insulation information of the insulating core, such as partial discharge monitoring. The multiple capacitor screens within the insulating core 10 form an equalizing capacitor C1, a voltage dividing capacitor C2, a shielding anti-interference capacitor C3, and an insulation information acquisition capacitor C4. The electrical schematic diagrams of the equalizing capacitor C1, voltage dividing capacitor C2, shielding anti-interference capacitor C3, and insulation information acquisition capacitor C4 can be found in [reference needed]. Figure 4 and Figure 5 Two implementation examples.

[0041] like Figure 1 , 4As shown, the insulating information capacitor screen 104 constituting the insulating information acquisition capacitor C4 is wrapped around the shielding anti-interference capacitor C3. The two ends of the series connection between the shielding anti-interference capacitor C3 and the insulating information acquisition capacitor C4 are connected in parallel to the two ends of the series-connected equalizing capacitor C1 and voltage dividing capacitor C2. The third lead is led out from between the shielding anti-interference capacitor C3 and the insulating information acquisition capacitor C4. Or, as shown... Figure 5 As shown, the insulating information capacitor screen 104 constituting the insulating information acquisition capacitor C4 is wrapped between the equalizing capacitor C1 and the voltage dividing capacitor C2. The insulating information acquisition capacitor C4 is connected in series between the equalizing capacitor C1 and the voltage dividing capacitor C2. The series-connected equalizing capacitor C1, insulating information acquisition capacitor C4 and voltage dividing capacitor C2 are connected in parallel with the shielding anti-interference capacitor C3. The third lead is led out from between the equalizing capacitor C1 and the insulating information acquisition capacitor C4 and extends to the outside of the insulating core 10.

[0042] This is existing technology in this field. In addition, existing technology usually also includes an air coil in the insulating core 10 as a current transformer to collect current signals, but this increases the radial dimension of the high-voltage electrical appliance and increases the difficulty of subsequent installation and maintenance.

[0043] The improvement of this application lies in that an optical fiber 201 is also embedded within the insulating core 10. The optical fiber 201 is wound with multiple turns to form an optical fiber coil 20. The optical fiber coil 20 has a first lead extending out of the insulating core 10 to serve as a current sensor, realizing the function of a current transformer and achieving current monitoring. By directly embedding the optical fiber 201 within the insulating core 10, this application constructs an integrated high-voltage sensor based on the insulating core 10. Firstly, it eliminates the need for an external hollow coil, reducing the size of the high-voltage sensor. Secondly, the solidified insulating core 10 protects the optical fiber 201 from damage and displacement. Thirdly, the optical fiber 201 can be closer to the conductor covered by the insulating core 10, which is beneficial for improving the strength of the acquired signal.

[0044] The optical fiber 201 can be wound on any insulating layer within the insulating core 10, forming an integral part of the insulating core 10. For example, the optical fiber 201 can be wound on the insulating layer between two adjacent capacitor screens of the insulating core 10, such as between two adjacent equalizing capacitor screens 101, or between two adjacent dividing capacitor screens 102, or between adjacent equalizing capacitor screens 101 and dividing capacitor screens 102, or between shielding capacitor screens 103 or insulating information capacitor screens 104. Preferably, the optical fiber 201 is wound on the insulating layer outside the equalizing capacitor C1 to avoid damage or influence from high potential. Alternatively, the optical fiber 201 can be wound on different insulating layers, i.e., multiple turns can be located on different insulating layers, which is also within the scope of this application, but will increase the construction difficulty.

[0045] In this embodiment, the optical fiber 201 is wound around the insulating layer on the outside of all the capacitor screens. Specifically, the optical fiber 201 is wound around the equalizing capacitor C1 and the dividing capacitor C2, and an insulating layer is then wrapped around the optical fiber 201 to form an integral insulating core 10, which facilitates construction. The insulating layer wound on the optical fiber coil 20 can be epoxy resin-impregnated glass fiber, heat shrink tubing, etc. In this embodiment, the insulating core 10 uses epoxy resin-impregnated glass fiber as the insulating layer and semiconducting tape or metal tape as the capacitor screen. The insulating layer and the capacitor screen are alternately wound around the conductor or insulating pillar to form a sleeve-shaped insulating core 10. Of course, other materials can also be used as the insulating layer and the capacitor screen.

[0046] Further, refer to Figure 7 In one embodiment, an oil chromatography detection fiber 202 is also provided inside the insulating core 10 for monitoring oil chromatography, and / or an oil temperature detection fiber 203 for monitoring oil temperature.

[0047] Thus, the capacitor-based insulating core 10 of this embodiment forms a multifunctional high-voltage sensor that functions as a current transformer, voltage transformer, harmonic monitoring, and partial discharge monitoring. It should be noted that, as in other embodiments, the insulation information capacitor screen 104, and / or the shielding capacitor screen 103, and / or the voltage divider capacitor screen 102 may be omitted as needed; that is, only the current transformer function may be implemented, which also falls within the scope of this application.

[0048] Example 1

[0049] like Figure 1-2 The illustrated embodiment is a high-voltage bushing, comprising an insulating core 10 covering a conductor 30, wherein the conductor 30 is a conductive rod or conductive tube. A mounting flange 40 is fixedly provided on the outer side of the middle part of the insulating core 10. The mounting flange 40 is used for fixed installation with power equipment. The mounting flange 40 divides the insulating core 10 into a first bushing part located outside the power equipment and a second bushing part for insertion into the power equipment. The end of the second bushing part can be provided with a plug-in contact to engage with the power equipment. The end of the first bushing part is provided with a terminal block and an equalizing ring, etc. An insulating skirt (not shown in the figure) is provided on the outer sleeve of the first bushing part. For example, the high-voltage bushing in this embodiment is a transformer bushing, which is plugged into and installed with a transformer. This is the prior art in this field.

[0050] Multiple capacitor screens are arranged alternately around the insulating layer within the insulating core 10. These capacitor screens include an equalizing capacitor screen 101 forming an equalizing capacitor C1, a voltage-dividing capacitor screen 102 forming a voltage-dividing capacitor C2, a shielding capacitor screen 103 forming a shielding anti-interference capacitor C3, and an insulation information capacitor screen 104 forming an insulation information acquisition capacitor C4. The equalizing capacitor C1 and the voltage-dividing capacitor C2 are connected in series to form a capacitor voltage divider, which functions as a voltage transformer. A second signal line extends from the equalizing capacitor C1 to the outside of the insulating core 10 and connects to external monitoring equipment via a second signal terminal 42. The multiple shielding capacitor screens 103 are arranged around at least a portion of the equalizing capacitor screen 101 to shield against external interference signals. The insulation information acquisition capacitor C4 is wound around the outside of the shielded anti-interference capacitor C3. The insulation information acquisition capacitor C4 and the shielded anti-interference capacitor C3 are connected in series. A third lead is connected between the shielded anti-interference capacitor C3 and the insulation information acquisition capacitor C4 and extends to the outside of the insulating core 10. It is connected to an external monitoring device through the second signal terminal 42 for monitoring insulation information such as partial discharge.

[0051] An optical fiber 201 is also embedded within the insulating core 10. The optical fiber 201 is wound with multiple turns to form an optical fiber coil 20, which functions as a current transformer to collect current signals. A first lead wire extends from the optical fiber coil 20 to the outside of the insulating core 10 and connects to an external monitoring device via a first signal terminal 41. The monitoring device includes a current sensor processing module, which comprises a light source and a signal processing unit. The light source emits light into the optical fiber 201. Utilizing the characteristic that the polarization plane of light rotates due to the magnetic field during propagation in the optical fiber, the signal processing unit detects and processes this polarization plane rotation characteristic to measure the current in the conductor 30. This is existing technology in the field and can be implemented using various existing solutions, such as transmission sensing, reflection sensing, or Sagnac interferometry sensing.

[0052] Figure 6A scheme for implementing a reflective sensing fiber optic current transformer is provided. An optical fiber coil 20, wound with optical fiber 201, is provided within the insulating core 10 of a high-voltage bushing. The optical fiber 201 is a sensing optical fiber. A λ / 4 waveplate and a reflector are also provided within the insulating core 10, connected to both ends of the optical fiber coil 20. One end of the optical fiber 201 is connected to the reflector. After being wound multiple turns, the optical fiber 201 is connected to the λ / 4 waveplate and extends from the insulating core 10. A monitoring device is provided in the ground potential area outside the high-voltage bushing. Optical signal transmission is achieved between the high-voltage bushing and the monitoring device via a polarization-maintaining optical cable. The monitoring device includes a current sensor processing module, which comprises a light source, a circulator, a polarizer, a phase modulator, a photoelectric converter, an A / D converter, and a signal processing unit. The output of the light source is connected to the first port of the circulator, the second port of the circulator is connected to the input of the polarizer, the output of the polarizer is connected to the input of the phase modulator, and the output of the phase modulator is connected to one end of the polarization-maintaining optical cable. The third port of the circulator is connected to the input of the photoelectric converter, the output of the photoelectric converter is connected to the input of the A / D converter, and the output of the A / D converter is connected to the input of the signal processing unit. The light emitted from the light source enters the polarizer via the circulator, then passes through the phase modulator and is transmitted to the high-voltage bushing via the polarization-maintaining optical cable. It is converted into circularly polarized light by a λ / 4 waveplate, propagates along the sensing fiber, and rotates due to the Faraday effect under the influence of the magnetic field generated by the current-carrying conductor. It is then reflected back by a mirror. During the return journey, due to the non-reciprocal nature of the λ / 4 waveplate, the polarization state undergoes an orthogonal transformation, forming an interference signal. The returned light passes through a phase modulator and polarizer, and is then sent to a photoelectric converter via a circulator. This converted light is then converted into an electrical signal, which is further processed by an A / D converter and a signal processing unit to achieve high-precision measurement of the current in the current-carrying conductor. The signal processing unit includes an MCU processor or a microcontroller.

[0053] As another implementation scheme of current transformer, only an optical fiber coil 20 wound with optical fiber 201 is provided in the insulating core 10 of the high voltage bushing. There is no need for λ / 4 wave plate and reflector. One end of the optical fiber 201 located in the insulating core 10 is a fiber grating. The fiber grating is used as the reflective element. That is, one end of the optical fiber coil 20 is a fiber grating, and the other end extends out as the first lead.

[0054] As another implementation scheme for fiber optic current transformers, transmission sensing can also be used. Only an optical fiber coil 20 wound with optical fiber 201 is provided within the insulating core 10 of the high-voltage bushing, eliminating the need for a λ / 4 waveplate and reflector. The current sensor processing module includes a light source, a polarizer, an analyzer, and a signal processing unit. Two first leads extend from both ends of the optical fiber coil 20 to the monitoring device in the ground potential region, realizing transmission sensing. One first lead (optical fiber) connects to the polarizer and the light source, and the other first lead (optical fiber) connects to the analyzer. The signal is processed by a photoelectric converter, an A / D converter, and the signal processing unit to monitor the current in the current-carrying conductor. Its drawbacks include low sensitivity to polarization state changes and the need for two round-trip transmission optical fibers. The optical fiber coil increases environmental interference and affects measurement accuracy. Obviously, the current sensor processing module can also use Sagnac interferometric sensing or other sensing methods, which will not be elaborated further.

[0055] In this embodiment, the insulating core 10 uses epoxy resin-impregnated glass fiber as the insulating layer, a semi-conductive strip or metal strip as the capacitor screen, and the optical fiber 201 is a sensing optical fiber. The insulating core 10 is wound on a conductive rod, with the insulating layer and capacitor screen alternately wrapped around the conductive rod to form the insulating core 10. Specifically, the multiple capacitor screens, from the inside to the outside of the insulating core 10, are respectively a voltage equalization capacitor screen 101, a voltage dividing capacitor screen 102, and a grounding capacitor screen. The multiple capacitor screens are basically coaxial and concentric. The multiple voltage equalization capacitor screens 101 and the insulating layer are alternately wrapped to form a voltage equalization capacitor C1. The multiple voltage equalization capacitor screens 101 gradually divide the high voltage to provide insulation. The innermost voltage equalization capacitor screen 101 is a high-voltage capacitor screen, used to connect to high voltage, and is electrically connected to the terminals of the high-voltage bushing at the same potential. The outermost voltage equalization capacitor screen 101 is connected to... The voltage dividing capacitor C2 consists of multiple stacked and insulated voltage equalizing capacitor screens 101 along the axial direction of the insulating core 10. A voltage dividing capacitor screen 102 is located between the equalizing capacitor screen 101 and the grounding capacitor screen. The voltage dividing capacitor C2 formed by the voltage dividing capacitor screens 102 is located outside the equalizing capacitor C1. The grounding capacitor screen is located outside the voltage dividing capacitor C2. A second lead is connected between the equalizing capacitor C1 and the voltage dividing capacitor C2, serving as the signal source for the voltage transformer and enabling its function. The grounding capacitor screen is connected to the mounting flange 40 for grounding. Multiple shielding capacitor screens 103 are located between the high-voltage capacitor screen and the grounding capacitor screen. These shielding capacitor screens 103 are stacked and insulated from one end of the insulating core 10 to the corresponding mounting flange 40 along the axial direction of the insulating core 10, radially wrapping around the equalizing capacitor C1 to shield against external signal interference. Among the multiple shielded capacitor screens 103, the innermost shielded capacitor screen 103 is connected to a high voltage, and the outermost shielded capacitor screen 103 is grounded. The two ends of the shielding anti-interference capacitor C3 are connected in parallel to the two ends of the series-connected equalizing capacitor C1 and voltage dividing capacitor C2, which is used to shield the signal source collected by the capacitor divider from external interference signals and improve the signal acquisition accuracy. The insulating information capacitor screen 104 is alternately wrapped around the shielded capacitor screen 103 with the insulating layer. The outermost voltage dividing capacitor screen 102, or the outermost shielded capacitor screen 103, or the outermost insulating information capacitor screen 104, or the grounding capacitor screen can be a single capacitor screen or multiple different capacitor screens. Fiber optic cables 201 are wound around the insulating layer on the outside of all capacitor screens, a λ / 4 waveplate and a reflector are placed inside, and the fiber optic cables 201, the λ / 4 waveplate and the reflector are wrapped with heat-shrink tubing to form an integrated insulating core 10. The heat-shrink tubing is the new insulating layer wrapped around the fiber optic cables 201. Since the outermost insulating layer of the insulating core 10 is relatively thick, it can be cured and shaped with epoxy resin, and grooves can be dug in the insulating core 10 without damaging the grounding capacitor screen to install the optical fiber 201, λ / 4 waveplate and reflector; and then the insulating core 10 is formed by wrapping with epoxy resin or heat shrink tubing.Then, a flange 40 is fixedly installed in the middle of the insulating core 10, dividing the insulating core 10 into a first part of the bushing located outside the power equipment and a second part of the bushing for insertion into the power equipment. The first signal line is led out from the first signal terminal 41, and the second and third signal lines are led out from the second signal terminal 42. A silicone rubber insulating skirt is installed on the first part of the bushing.

[0056] It should be noted that, in other embodiments, the voltage equalizing capacitor screen 101 can be divided into at least two groups. One group is disposed within the first part of the bushing, gradually reducing the high voltage to a low voltage to achieve insulation protection; the other group is disposed within the second part of the bushing, similarly gradually reducing the high voltage to a low voltage to achieve insulation protection. The voltage dividing capacitor screen 102, the shielding capacitor screen 103, and the insulation information capacitor screen 104 are disposed within the first part of the bushing. In another optional embodiment, the positions of the voltage dividing capacitor screen 102, the shielding capacitor screen 103, and the insulation information capacitor screen 104 can be different. In another optional embodiment, the insulation information capacitor screen 104, and / or the shielding capacitor screen 103, and / or the voltage dividing capacitor screen 102 can be omitted as needed. In another optional embodiment, only one signal terminal or more signal terminals can be provided, all of which fall within the scope of protection of this application.

[0057] Example 2

[0058] like Figure 7-8 The high-voltage bushing of Embodiment 2 shown is structurally identical to that of Embodiment 1, including an insulating core 10 covering the conductor 30. The insulating core 10 includes a first bushing part and a second bushing part. The second bushing part is inserted into the transformer for electrical connection and extends into the transformer's insulating oil. The first bushing part is covered with an insulating skirt (not shown in the figure) located outside the transformer. Multiple capacitor screens are arranged alternately around the insulating layer within the insulating core 10. An optical fiber 201 is also embedded within the insulating core 10. The optical fiber 201 is wound with multiple turns to form an optical fiber loop 20, used to realize the function of a current transformer. The identical parts are not repeated.

[0059] The difference between Embodiment 2 and Embodiment 1 is that an oil chromatography detection fiber optic cable 202 and an oil temperature detection fiber optic cable 203 are also provided inside the insulating core. The first monitoring end of the oil chromatography detection fiber optic cable 202 extends slightly from the second part of the bushing, and the other end extends from the first part of the bushing as a fourth lead-out wire, connected to an external monitoring device via a first signal terminal 41. After the second part of the bushing is inserted into the transformer, the first monitoring end is immersed in the transformer's insulating oil to monitor the oil chromatography, thereby monitoring the quality status of the insulating oil. Similarly, the second monitoring end of the oil temperature detection fiber optic cable 203 extends slightly from the second part of the bushing, and the other end extends from the first part of the bushing as a fifth lead-out wire, connected to an external monitoring device via a first signal terminal 41. After the second part of the bushing is inserted into the transformer, the oil temperature detection fiber optic cable 203 is immersed in the transformer's insulating oil to monitor the oil temperature.

[0060] The high-voltage bushing in this embodiment not only has the function of a bushing, but also has the functions of oil temperature detection and oil chromatography detection. It does not require separate opening for oil temperature detection or laying of pipeline for oil chromatography detection. Moreover, the solidified insulating core 10 can protect the oil chromatography detection optical fiber 202 and the oil temperature detection optical fiber 203 from damage, eliminating the need for additional high-voltage isolation structures and protective shells.

[0061] The oil chromatography detection fiber 202 is a hollow-core fiber (HCF), allowing insulating oil to enter at least the first monitoring end of the hollow fiber for oil chromatography detection. Like traditional glass-core fibers, the hollow-core fiber consists of a core, cladding, and coating. Its core is air, and the cladding is based on a microstructure design, typically composed of a series of tiny air holes arranged along the length of the fiber to form a specific periodic structure. The cross-section of the cladding resembles a honeycomb composed of fine silicon filaments, which is existing technology in this field.

[0062] In one optional embodiment, the first monitoring end is a hollow optical fiber, and the insulating oil can enter at least into the first monitoring end of the hollow optical fiber. The hollow optical fiber transmits light from the light source to the first monitoring end part with low loss. The insulating oil interacts with the light, and the resulting Raman spectrum is transmitted back through the hollow optical fiber.

[0063] A further preferred embodiment is provided, wherein the first monitoring end is a hollow fiber optic sensing head, specifically, the first monitoring end has nanoscale micropores arranged in the radial direction of the hollow fiber optic cable, forming a hollow fiber optic sensing head. This allows the insulating oil introduced into the hollow fiber optic sensing head to interact well with light, and the generated Raman spectrum is transmitted back through the hollow fiber optic cable. The micropore structure ensures good contact between the oil and light. Simultaneously, the micropores not only make it easier for the insulating oil to enter the hollow fiber optic cable, but also ensure that the measured insulating oil is flowable rather than fixed, improving the accuracy of oil chromatographic monitoring. The perforation of the hollow fiber optic cable is performed using a femtosecond laser and... Laser-based, ultrashort pulses focused on the sidewalls, nonlinear absorption enables precise ablation of materials with almost no thermal effects or microcracks.

[0064] Preferably, the second monitoring end of the oil temperature detection fiber optic cable 203 is a fiber optic temperature sensor. In this embodiment, the fiber optic temperature sensor is a fiber optic grating, which measures the oil temperature by changing the physical properties of light transmitted in the fiber with temperature.

[0065] The monitoring device includes a laser oil chromatography sensor processing module and a fiber optic temperature sensor processing module. The laser oil chromatography sensor processing module is connected to the fourth lead of the oil chromatography detection fiber optic cable 202 for detecting oil chromatograms. The laser oil chromatography sensor processing module includes a light source and a signal processing unit, and can be implemented using existing chromatographic detection technology or by purchasing existing oil chromatography detection equipment. The fiber optic temperature sensor processing module is connected to the fifth lead of the oil temperature detection fiber optic cable 203 for detecting oil temperature. The fiber optic temperature sensor processing module includes a light source and a signal processing unit, and can be implemented using existing fiber optic temperature detection technology or by purchasing existing fiber optic temperature detection equipment.

[0066] like Figure 9 As shown, an embodiment of a laser oil chromatography sensor processing module is provided. The high-voltage bushing and monitoring equipment are connected via a hollow-core optical fiber cable for optical signal transmission. The laser oil chromatography sensor processing module includes a pump laser, a hollow-core optical fiber circulator, a photoelectric converter, an A / D converter, and a signal processing unit. The output of the pump laser is connected to the first port of the hollow-core optical fiber circulator; the second port of the hollow-core optical fiber circulator is connected to one end of the hollow-core optical fiber cable; the third port of the circulator is connected to the input of the photoelectric converter; the output of the photoelectric converter is connected to the input of the A / D conversion circuit; and the output of the A / D converter is connected to the input of the signal processing unit.

[0067] The optical signal emitted by the pump light source is transmitted sequentially through a circulator and a hollow optical fiber cable to the oil chromatography test area. The Raman spectral signal excited by the pump light returns to the circulator along the original path and is then transmitted to a photoelectric converter. The electrical signal obtained by the photoelectric converter is processed sequentially by an A / D converter and a signal processing unit to achieve chromatographic detection. The signal processing unit includes an MCU processor or microcontroller, as well as peripheral circuits such as filtering circuits. If necessary, the signal processed by the signal processing unit can also be output to external dedicated equipment for analysis.

[0068] like Figure 10 As shown, an embodiment of a fiber optic temperature sensor processing module is provided, in which a high-voltage bushing and a monitoring device are connected via an optical cable for optical signal transmission. The fiber optic temperature sensor processing module includes a broadband light source, a circulator, a photoelectric converter, an A / D converter, and a signal processing unit. The output of the broadband light source is connected to the first port of the circulator; the second port of the circulator is connected to one end of the optical cable; the third port of the circulator is connected to the input of the photoelectric converter; the output of the photoelectric converter is connected to the input of the A / D conversion circuit; and the output of the A / D converter is connected to the input of the signal processing unit. The optical signal emitted by the light source is transmitted sequentially through the circulator and the optical cable to the fiber optic grating temperature measurement area. The optical signal reflected by the fiber optic grating returns along the original path to the circulator and is then transmitted by the circulator to the photoelectric converter. The electrical signal obtained by the photoelectric converter is processed sequentially by the A / D converter and the signal processing unit to achieve temperature detection. The signal processing unit includes an MCU processor or microcontroller, as well as peripheral circuits such as filtering circuits. If necessary, the signal processed by the signal processing unit can also be output to external dedicated equipment for analysis.

[0069] like Figure 7-8As shown, the oil chromatography detection fiber 202 extends along the axis of the insulating core 10, distributed in the first and second parts of the sleeve. The first monitoring end extends from the second part of the sleeve of the insulating core 10, and the other end is led out from the first signal terminal 41 as a fourth lead. The oil temperature detection fiber 203 extends along the axis of the insulating core 10, distributed in the first and second parts of the sleeve. The second monitoring end extends from the second part of the sleeve of the insulating core 10, and the other end is led out from the first signal terminal 41 as a fifth lead. The oil chromatography detection fiber 202 and the oil temperature detection fiber 203 can be disposed on any insulating layer within the insulating core 10, forming an integral part of the insulating core 10. For example, they can be disposed on the insulating layer between two adjacent capacitor screens of the insulating core 10. Preferably, the oil chromatography detection fiber 202 and the oil temperature detection fiber 203 are disposed on the insulating layer outside the equalizing capacitor C1 to avoid damage or influence of high potential on the fiber 201. The oil chromatography detection fiber 202 and the oil temperature detection fiber 203 can be placed on different insulation layers.

[0070] In this embodiment, both the oil chromatography detection fiber 202 and the oil temperature detection fiber 203 are disposed on the insulating layer on the outer side of all the capacitor screens. The oil chromatography detection fiber 202 and the oil temperature detection fiber 203 are respectively disposed at different positions on both radial sides of the insulating core 10. Without damaging the grounding capacitor screen, grooves can be dug in the insulating core 10 to install the oil chromatography detection fiber 202 and the oil temperature detection fiber 203, and then the insulating core 10 can be formed integrally by wrapping it with epoxy resin or heat shrink tubing.

[0071] Preferably, a hollow protective tube (not shown in the figure) is also provided outside the first monitoring end of the oil chromatography detection fiber 202 and / or the second monitoring end of the oil temperature detection fiber 203, which can protect the first and second monitoring ends, and the insulating oil can also enter the protective tube.

[0072] Furthermore, the protective tube is not only hollow in the axial direction, but also has multiple small holes in the radial direction, which allows the insulating oil to flow and improves the reliability of the test results, rather than continuously testing the insulating oil in a fixed part.

[0073] The high-voltage bushing in this embodiment not only has the function of a bushing, but also the functions of a current sensor, voltage sensor, oil temperature sensor, and oil chromatography sensor, forming a multi-functional high-voltage sensor based on the high-voltage bushing. When installed on a transformer, it can eliminate the need for existing independent current transformers, voltage transformers, oil temperature detection equipment, and oil chromatography detection equipment, greatly reducing the size of the transformer combined electrical equipment and the footprint of the high-voltage equipment.

[0074] Obviously, as another optional solution in Embodiment 2, only one of the oil chromatography detection fiber 202 or the oil temperature detection fiber 203 can be provided. As another optional solution in Embodiment 2, the fiber optic loop 20 wound around the fiber optic 201 can also be omitted, and an independent current transformer coil can be sleeved outside the insulating core 10.

[0075] It should be noted that the high-voltage sensor based on an insulating core created by this invention is not limited to the transformer bushings of the above embodiments, but can also be used in wall bushings or other high-voltage bushings with similar structure and function. Furthermore, the high-voltage sensor based on an insulating core created by this invention can also be used in various other types of high-voltage electrical appliances such as current transformers, cable terminals, disconnecting switches, circuit breakers, surge arresters, and insulators, as long as it includes a capacitive insulating core 10 passing through the conductor. The oil temperature detection and oil chromatography detection functions of this embodiment are not limited to transformer oil monitoring, but can also be used in equipment that uses insulating oil and needs to be connected to high-voltage electrical appliances, such as oil temperature detection and oil chromatography detection of oil-immersed reactors, etc., installed on bushings or surge arresters connected to oil-immersed reactors, wherein the bushings or surge arresters include the high-voltage sensor based on an insulating core of this application.

[0076] For example, the insulating core 10 in Implementation 1 can remove the insulating information capacitor screen 104, shielding capacitor screen 103, and voltage dividing capacitor screen 102, and can be connected to a high-voltage line as a new type of current transformer.

[0077] For example, in one embodiment of a cable terminal, the cable terminal includes an insulating core 10. One end of the insulating core 10 has a mounting flange, and the other end has an upper flange and a terminal block. The insulating core 10 covers a conductive rod. A stress cone is also provided inside one end of the cavity of the insulating core 10. The stress cone is fitted onto the cable and tightly pressed into the insulating core 10. The conductor end of the cable is electrically connected and fixed to the conductive rod. An insulating skirt 23 is provided over the insulating core 10. This is prior art in the art. Multiple capacitor screens are arranged alternately around the insulation layer within the cable terminal. The capacitor screens include multiple voltage-equalizing capacitor screens 101 for achieving high-voltage insulation. An optical fiber 201 is provided within the insulating core 10. The optical fiber 201 is wound with multiple turns to form an optical fiber loop 20, which functions as a current transformer.

[0078] In embodiment three, this application also provides a high-voltage monitoring system, including the high-voltage electrical appliance of this application and a monitoring device connected to the high-voltage electrical appliance. The high-voltage electrical appliance includes the high-voltage sensor based on the capacitive insulating core of this application. The monitoring device is able to detect the current signal and voltage signal flowing through the conductor, monitor harmonics, and monitor partial discharge based on the high-voltage sensor.

[0079] This application also provides a high-voltage monitoring system, including the high-voltage bushing of this application and a monitoring device connected to the high-voltage bushing. The monitoring device is capable of detecting current signals and voltage signals flowing through the conductor, monitoring harmonics, monitoring partial discharge, and monitoring the chromatogram and oil temperature of the insulating oil in the transformer based on the high-voltage sensor of the insulating core of the high-voltage bushing.

[0080] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the inventive concept, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A high-voltage sensor, comprising an insulating core (10), wherein a plurality of capacitive screens are disposed within the insulating core (10) and alternately arranged around an insulating layer, the capacitive screens including a plurality of voltage-equalizing capacitive screens (101) for achieving high-voltage insulation, characterized in that: An optical fiber (201) is also provided inside the insulating core (10). The optical fiber (201) is wound with multiple turns to form an optical fiber loop (20). The optical fiber loop (20) is connected to a first lead wire that extends out of the insulating core (10) and is used as a current sensor.

2. The high-voltage sensor according to claim 1, characterized in that: The optical fiber (201) is wound on any one of the insulating layers inside the insulating core (10).

3. The high-voltage sensor according to claim 1, characterized in that: The optical fiber (201) is wound on the insulating layer between two adjacent capacitor screens of the insulating core (10), or the optical fiber (201) is wound on the insulating layer outside all the capacitor screens, and an insulating layer is set outside the optical fiber (201) to form an integral insulating core (10).

4. The high-voltage sensor according to claim 1, characterized in that: The plurality of capacitive screens include a voltage equalizing capacitor screen (101) forming a voltage equalizing capacitor (C1) and a voltage dividing capacitor screen (102) forming a voltage dividing capacitor (C2). The voltage equalizing capacitor (C1) and the voltage dividing capacitor (C2) are connected in series to form a capacitor voltage divider. A second signal line is connected between the voltage equalizing capacitor (C1) and the voltage dividing capacitor (C2) and extends to the outside of the insulating core (10).

5. The high-voltage sensor according to claim 4, characterized in that: The plurality of capacitive screens also include a plurality of shielded capacitive screens (103) forming a shielded anti-interference capacitor (C3). The plurality of shielded capacitive screens (103) are alternately arranged with an insulating layer and at least surround a portion of the equalizing capacitive screen (101) for shielding external interference signals.

6. The high-voltage sensor according to claim 5, characterized in that: The plurality of capacitive screens also include an insulating information capacitive screen (104) forming an insulating information acquisition capacitor (C4). The insulating information acquisition capacitor (C4) is wound around the outside of the shielding anti-interference capacitor (C3). The insulating information acquisition capacitor (C4) and the shielding anti-interference capacitor (C3) are connected in series. A third lead is connected between the shielding anti-interference capacitor (C3) and the insulating information acquisition capacitor (C4) and extends to the outside of the insulating core (10). Alternatively, the insulating information acquisition capacitor (C4) is located between the equalizing capacitor (C1) and the dividing capacitor (C2). The insulating information acquisition capacitor (C4) is connected in series between the equalizing capacitor (C1) and the dividing capacitor (C2). The series-connected equalizing capacitor (C1), insulating information acquisition capacitor (C4) and dividing capacitor (C2) are connected in parallel with the shielding anti-interference capacitor (C3). The third lead is led out from between the equalizing capacitor (C1) and the insulating information acquisition capacitor (C4) and extends to the outside of the insulating core (10).

7. The high-voltage sensor according to claim 1, characterized in that: A λ / 4 waveplate and a reflector are also provided inside the insulating core (10), and the λ / 4 waveplate and the reflector are connected to both ends of the fiber coil (20).

8. The high-voltage sensor according to claim 1, characterized in that: One end of the fiber optic loop (20) is a fiber grating, and the other end extends out as the first lead; or, two first leads extend from both ends of the fiber optic loop (20).

9. The high-voltage sensor according to claim 1, characterized in that: The insulating core also contains an oil chromatography detection fiber (202) and an oil temperature detection fiber (203).

10. The high-voltage sensor according to claim 1, characterized in that: The insulating core (10) uses epoxy resin-impregnated glass fiber as the insulating layer, and a semi-conductive strip or metal strip as the capacitor screen. The optical fiber (201) is a sensing optical fiber. The optical fiber (201) is wound on the insulating layer on the outside of all the capacitor screens and the optical fiber (201) is covered by the insulating layer.

11. A high-voltage electrical appliance, characterized in that: The high-voltage electrical appliance includes the high-voltage sensor according to any one of claims 1-10.

12. The high-voltage electrical appliance according to claim 11, characterized in that: The high-voltage electrical equipment is any one of bushings, cable terminals, current transformers, disconnect switches, circuit breakers, surge arresters, and insulators.

13. A high-pressure bushing, characterized in that: The high-voltage bushing includes the high-voltage sensor according to any one of claims 1-10.

14. A high-voltage monitoring system, characterized in that: It includes the high-voltage electrical appliance as described in claim 11 or 12, and the monitoring equipment connected to the high-voltage electrical appliance.

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