Multi-parasitic oscillator ultrahigh frequency partial discharge detection antenna

Abstract

The invention discloses a multi-parasitic array ultrahigh frequency partial discharge detection antenna. The antenna comprises an antenna radiation oscillator, a metal sleeve pressing block, a first metal reflection disc, a parasitic oscillator, a second metal reflection disc, a first medium supporting body, a second medium supporting body and a reflection base plate which are sequentially and fixedly installed in series in the axial direction of the antenna. By adopting a composite gradual change combination result, a metal sleeve, a parasitic array subarray and other broadband impedance conversion ring means, impedance conversion, working bandwidth expansion, broadband radiation capability improvement and antenna radiation physical size reduction are realized. The multi-parasitic-oscillator ultrahigh-frequency partial discharge detection antenna structure is small in installation size, meets the installation requirements of bottom contour and miniaturization in a closed and limited space, and is suitable for being applied to various scenes. Besides, the antenna with the design can meet the requirements of vertical polarization and symmetrical omnidirectional radiation on the working frequency band of 300MHz-1500MHz, and the radiation efficiency of the antenna is better.

Description

Technical Field

[0001] This invention relates to the field of ultra-high voltage online partial discharge monitoring technology, and mainly to a multi-parasitic array ultra-high frequency partial discharge detection antenna. Background Technology

[0002] In high-voltage, ultra-high-voltage, and extra-high-voltage power distribution systems, partial discharge signal monitoring of gas-insulated switchgear (GIS) is an important means of assessing the health of power equipment systems. Existing methods for monitoring discharge signals in GIS include ultrasonic waves, current pulses, and ultra-high frequency (UHF) methods, each with its own advantages. However, only the UHF method possesses multiple characteristics such as long-range acquisition, target identification, and interference localization, and it is easily integrated with intelligent health management systems for backend data management. Partial discharge signals are generally caused by ionization and breakdown of metal particles, sharp metals, dielectric surfaces, and internal dielectric filling gaps in GIS within high-voltage, high-field-strength environments. Continuous partial discharge alters the chemical and physical structure of the insulating material, leading to structural component failure and functional degradation, and causing high-voltage ionization arcing that damages high-voltage transmission lines. Partial discharge signals, as a form of interference energy, propagate in GIS as electromagnetic waves, primarily in the 300MHz–1500MHz frequency band.

[0003] The detection of UHF partial discharge signals was first explored in the late 1980s by Hampton and Meats, who used a UHF antenna in a gas-insulated substation to detect free metal particle discharge phenomena (Hampton B, Meats RJ. Diagnostic measurements at UHF in gas insulated substations. IEE Proc C Gener Transm Distrib 135(2):137-145). Their research used a monopole antenna as the UHF antenna sensor model, which had a relatively simple structure and limited functionality, only capable of point-frequency detection, and could not meet the requirements for detection in the 300MHz~1500MHz frequency band. Another type is the capacitor disk-type pole antenna, proposed by M.D. Judd and O. Farish of the University of Strathclyde, UK in 1995 (Judd M, Farish O. Broadband couplers for UHF detection of partial discharge in gas-insulated substations. IEE Proc Sci Meas Technol 142(3): 237-243). The pole antenna structure with a reflector disk and a metal capacitor disk loaded on top extends the operating frequency band of the system. However, the introduction of the capacitor disk increases the physical size of the detection system. Especially when it is smaller than 150mm, its working capacity drops sharply, which cannot meet the requirements of miniaturized installation. With the improvement of modern circuit manufacturing processes, optimized Hilbert curve antennas have been etched onto PCBs to operate in the UHF band, such as the partial discharge detection antenna design proposed by scholars Li J and Jiang T (Li J, Jiang T. Optimization of UHF Hilbert antenna for partial discharge detection of transformers. IEEE Trans Antennas Propag60(5):2536-2540, 2012.). However, in high-voltage environments, the dielectric material of PCB antennas is prone to self-discharge. The higher the ambient voltage, the greater the probability of discharge, which can easily lead to electric field breakdown and arcing, posing a safety hazard. This makes such antennas unsuitable for use in high electric field environments. With the continuous improvement of safety requirements for various high-voltage, ultra-high-voltage, and extra-high-voltage transmission lines and power distribution equipment, UHF antenna detection devices for partial discharge detection must also meet the requirements of easy internal installation, symmetrical omnidirectional radiation, and avoidance of self-discharge in high electric field environments.How to achieve the characteristics of partial discharge measurement antennas that meet space constraints, have wide bandwidth, high efficiency, and low cost is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] According to an embodiment of the present invention, to overcome the above-mentioned shortcomings of the prior art, a multi-parasitic array ultra-high frequency partial discharge detection antenna is provided, comprising an antenna radiating array, a metal sleeve clamping block, a first metal reflector, a parasitic array, a second metal reflector, a first dielectric support, a second dielectric support, and a reflective base, which are sequentially and serially fixed along the antenna axis. The antenna radiating array is an axisymmetric rotating body; the metal sleeve clamping block is disposed outside the antenna radiating array, with a portion of its bottom surface located on the upper surface of the first metal reflector and a portion of its bottom surface pressed against the upper surface of the first dielectric support; the first metal reflector is disposed outside the antenna radiating array, with its outer bottom surface flush and tangentially mounted to the upper surface of the reflective base, and its bottom surface embedded in a through hole of the reflective base; the parasitic array is symmetrically arranged around the radiating array along the antenna radiating array axis and penetrates the upper surface of the second metal reflector and is fixed to the second metal reflector; the second metal reflector is a component that is symmetrically arranged along the antenna radiating array axis. A symmetrical rotating body has its bottom surface flush and tangent to the upper surface of the reflective base. The inner ring surface of its rotating body is in contact with the outer surface of the first metal reflective disk, and it is distributed around the outside of the first metal reflective disk. The first dielectric support is a rotating annular body, located outside the antenna radiating array, and embedded inside the first metal reflective disk, ensuring that its upper surface is flush with the upper surface of the first metal reflective disk. The second dielectric support is a rotating body, located outside the antenna radiating array, and embedded inside the first metal reflective disk, ensuring that its lower surface is flush with the lower surface of the first metal reflective disk. The base has a first mounting through hole.

[0005] Preferably, the antenna radiating element is made of hard aluminum, and its structure consists of two parts from top to bottom: a radiator and a feed element. The radiator, from top to bottom, comprises three parts: a coaxial radiating cylinder, a coaxial radiating extension frustum, and an impedance matching radiating ring. The coaxial radiating cylinder is connected in series with the feed element, its bottom surface is tangentially connected to the top surface of the feed element, and its diameter is 0.06 times the wavelength, with a height of 0.122 times the wavelength. The coaxial radiating extension frustum has a smaller diameter, its bottom surface is tangentially connected to the top surface of the coaxial radiating cylinder, and its diameter is the same as the diameter of the coaxial radiating cylinder. The coaxial radiating extension frustum has a larger diameter, its top surface dimension is 0.234 times the wavelength, and its height is 0.075 times the wavelength. The impedance matching radiating ring wraps around the outer edge of the larger diameter upper surface of the coaxial radiating frustum. Its inner diameter is 3mm smaller than the diameter of the larger upper surface of the coaxial radiating frustum. The outer diameter is calculated using electromagnetic optimization to optimize the antenna standing wave parameters within the antenna's operating frequency band. The feed element consists of four coaxial and serially fixed parts: an upper cylinder, a second cylinder, a frustum, and a lower cylinder. The upper cylinder is located inside the feed cylinder of the radiating element, with its bottom end flush with the bottom end of the feed cylinder of the radiating element. The second cylinder is located away from the radiating element, with its upper surface connected to the bottom end of the upper cylinder and its bottom end connected to the larger diameter bottom surface of the frustum. The frustum is located away from the bottom end of the feed cylinder of the radiating element, with its larger diameter top surface connected to the bottom end of the upper cylinder and its smaller diameter bottom surface connected to the top end of the lower cylinder. The lower cylinder is located away from the radiating element. Its top end is connected to the bottom surface of the frustum with a smaller diameter. Its bottom end is flush with the bottom end of the dielectric sleeve and the second dielectric support and is also flush with the upper surface of the first step of the chassis through hole. Its bottom end has an M3 through hole for connecting to the radio frequency plug.

[0006] Preferably, the first dielectric support material is polyetheretherketone, and its structure is a rotating cylinder with an outer diameter of 0.144 times the wavelength, an inner diameter of 0.043 times the wavelength, and a height of 0.037 times the wavelength. It is located outside the antenna radiating element and embedded inside the first metal reflector, ensuring that its upper surface is flush with the upper surface of the first metal reflector.

[0007] Preferably, the second dielectric support material is polyetheretherketone (PEEK), and its structure is a rotating body composed of two stacked and fixed frustums connected in series. It is positioned outside the antenna radiating element and embedded inside the first metal reflector, ensuring that its lower surface is flush with the lower surface of the first metal reflector. The inner diameter of the rotating body is 0.013 times the wavelength. The first cylindrical layer has an outer diameter of 0.058 times the wavelength and a height of 0.015 times the wavelength. The second frustum has an outer diameter of 0.036 times the wavelength and a height of 0.006 times the wavelength.

[0008] Preferably, the metal sleeve pressing block is made of hard aluminum and has a hollow cylindrical structure. The outer diameter of the cylinder is 0.21 times the wavelength, the inner diameter is 0.108 times the wavelength, and the height is 0.105 times the wavelength. The metal sleeve pressing block is located outside the antenna radiating element. Three-quarters of its bottom surface in the outer radial direction is located on the upper surface of the first metal reflector, and one-quarter of its bottom surface in the inner radial direction is pressed against the upper surface of the first dielectric support.

[0009] Preferably, the first metal reflector is made of hard aluminum, and its overall structure consists of three interconnected rings and a composite cylinder. The upper ring has an outer diameter of 0.276 times the wavelength, and its inner diameter and thickness are the same as the outer diameter and thickness of the first dielectric support. Its bottom surface is tangent to and flush with the upper surface of the middle ring and the upper surface of the reflector base. The middle ring has an outer diameter of 0.171 times the wavelength, its inner diameter is the same as the outer diameter of the first dielectric support, and its thickness is 0.006 times the wavelength. Its lower surface is flush with the upper surface of the lower ring. The lower ring has an outer diameter of 0.144 times the wavelength, its inner diameter is 0.102 times the wavelength, and its thickness is 0.038 times the wavelength. Its lower surface is flush with the upper surface of the composite cylinder. The composite cylinder structure is composed of a hollow frustum and a cylinder. The larger diameter of the upper surface of the hollow cylindrical platform is the same as the diameter of the lower ring, and its height is 0.0512 times the wavelength. The smaller diameter of the lower surface is the same as the outer diameter of the second-layer cylinder of the second dielectric support, and it is in close contact with the upper surface of the hollow cylinder. The outer diameter and height of the cylinder are the same as those of the second-layer cylinder of the second dielectric support.

[0010] Preferably, the parasitic inductor material is hard aluminum, and the overall structure consists of spheres and cylinders connected vertically in a series along the axial direction. The upper end is a sphere with a diameter of 0.06 wavelengths, and the lower end is a cylinder with a diameter equal to the radius of the sphere and a height of 0.12 wavelengths. A total of six parasitic inductors form an array, which are fixed at 60° intervals around the radiating inductor along its height axis, with the inductor's height axis 0.168 wavelengths away from the radiating inductor's height axis. The parasitic inductors penetrate the upper surface of the second metal reflector and are fixed to it.

[0011] Preferably, the second metal reflector is made of hard aluminum, and its overall structure is a rotating body with an inverted trapezoidal cross-section. The top (smaller) rotating surface of the trapezoid is at the same height and tangent to the outer edge of the annular structure on the first metal reflector. The bottom (larger) rotating surface of the trapezoid has a height of 0.166 times the wavelength. The height side of the trapezoid has a dimension of 0.171 times the wavelength, and the surface formed by its rotation is tangent to and flush with the upper surface of the reflector base.

[0012] Preferably, the reflector base is made of hard aluminum and has a disc-shaped structure. A mounting through-hole is located at the center of the disc and consists of two interconnected hollow cylinders. The diameter of the first cylinder is the same as the diameter and height of the bottom of the second metal pressure block. The diameter and height of the second cylinder meet the requirements for installing commercially available N-type RF connectors. The central axis of the mounting through-hole is the axis connecting the antenna radiating element, the first metal pressure block, the second metal pressure block, the first dielectric support, and the second dielectric support.

[0013] Beneficial Effects: According to an embodiment of the present invention, a multi-parasitic element ultra-high frequency partial discharge detection antenna can achieve impedance transformation, expand the operating bandwidth, enhance broadband radiation capability, and reduce the physical size of the antenna radiation by employing a broadband sleeve structure and an equivalent broadband radiator composed of parasitic element arrays. The structural design of this embodiment can reduce the physical installation size, meeting the requirements for concealed installation in narrow spaces, and is applicable to various scenarios. Furthermore, the antenna designed above can meet the requirements of vertical polarization and symmetrical omnidirectional radiation in the 300MHz~1500MHz operating frequency band, and achieves optimal antenna radiation efficiency.

[0014] Attached image description: Figure 1 This is a schematic diagram of a multi-parasitic array ultra-high frequency partial discharge detection antenna according to an embodiment of the present invention; Figure 2 This is a side view schematic diagram of a multi-parasitic array ultra-high frequency partial discharge detection antenna according to an embodiment of the present invention; Figure 3 This is an exploded structural diagram of a multi-parasitic array ultra-high frequency partial discharge detection antenna according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the antenna radiating element structure of a multi-parasitic element ultra-high frequency partial discharge detection antenna according to an embodiment of the present invention; Figure 5 The return loss curve of a multi-parasitic array ultra-high frequency partial discharge detection antenna according to an embodiment of the present invention; Figure 6 This is a typical frequency elevation plane radiation curve of a multi-parasitic array ultra-high frequency partial discharge detection antenna according to an embodiment of the present invention; Figure 7 This is a typical frequency azimuth radiation pattern curve of a multi-parasitic array ultra-high frequency partial discharge detection antenna according to an embodiment of the present invention; In the figure: 1. Antenna radiating element, 2. Metal sleeve clamping block, 3. First metal reflector, 4. Parasitic element, 5. Second metal reflector, 6. First dielectric support, 7. Second dielectric support, 8. Reflecting chassis, 9. Radio frequency connector.

[0015] Detailed Description of Embodiments: The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, further illustrating the present invention.

[0016] First, combine Figures 1 to 4 This invention describes a multi-parasitic array ultra-high frequency partial discharge detection antenna, which is widely used in partial discharge monitoring in gas-insulated switchgear and other scenarios. By employing electromagnetic calculation and analysis methods, and continuously optimizing and adjusting the structural dimensions of the antenna radiating array, metal sleeve clamping block, first metal reflector, parasitic array, second metal reflector, first dielectric support, and second dielectric support, an antenna scheme that meets the standing wave ratio and radiation pattern requirements of the desired operating frequency band can be obtained. The specific implementation method is as follows: like Figure 1 , 2 As shown, an embodiment of the present invention provides a multi-parasitic array ultra-high frequency partial discharge detection antenna, comprising an antenna radiating array, a metal sleeve pressing block, a first metal reflector, a parasitic array, a second metal reflector, a first dielectric support, a second dielectric support, and a reflective chassis.

[0017] Specifically, such as Figure 1 , 2As shown, the antenna radiating element is made of hard aluminum, and its structure consists of two parts from top to bottom: a radiator and a feed element. The radiator, from top to bottom, comprises a coaxial radiating cylinder, a coaxial radiating extension frustum, and an impedance matching radiating ring. The coaxial radiating cylinder is connected in series with the feed element; its bottom surface is tangentially connected to the top surface of the feed element. The cylinder has a diameter of 20mm and a height of 41mm. The coaxial radiating extension frustum, with a smaller diameter, has a bottom surface tangentially connected to the top surface of the coaxial radiating cylinder, and its diameter is the same as that of the coaxial radiating cylinder. The coaxial radiating extension frustum has a larger diameter, with an upper surface dimension of 78mm and a height of 25mm. The impedance matching radiating ring wraps around the outer edge of the larger diameter upper surface of the coaxial radiating extension frustum. Its inner diameter is 3mm smaller than the larger diameter of the larger upper surface of the coaxial radiating extension frustum. The outer diameter will be calculated using electromagnetic optimization to achieve the optimal antenna standing wave parameters within the antenna's operating frequency band. The feed element comprises four coaxial and serially fixed parts: an upper cylinder, a second cylinder, a frustum, and a lower cylinder. The upper cylinder is located inside the feed cylinder of the radiating element, with its bottom end flush with the bottom end of the feed cylinder of the radiating element. The second cylinder is located away from the radiating element, with its upper surface connected to the bottom end of the upper cylinder and its bottom end connected to the larger-diameter bottom surface of the frustum. The frustum is located away from the bottom end of the feed cylinder of the radiating element, with its larger-diameter top surface connected to the bottom end of the upper cylinder and its smaller-diameter bottom surface connected to the top end of the lower cylinder. The lower cylinder is located away from the radiating element, with its top surface connected to the smaller-diameter bottom surface of the frustum, and its bottom end flush with the bottom end of the dielectric sleeve and the second dielectric support, as well as flush with the upper surface of the first step of the chassis through-hole. An M3 through-hole is provided at its bottom end for connection to the RF connector. The antenna radiating element extends the antenna's radiation path by employing a design that superimposes multiple layers of gradient geometry on a series of radiating elements. This achieves a balanced distribution of current on the antenna surface, avoids current concentration in specific areas causing reflection loss, reduces the conductor length for current distribution, thereby expanding the antenna's operating frequency band and reducing its size.

[0018] Preferably, the first dielectric support material is polyetheretherketone, and its structure is a rotating cylinder with an outer diameter of 48 mm, an inner diameter of 14 mm, and a height of 12.3 mm. It is located outside the antenna radiating element and embedded inside the first metal reflector, ensuring that its upper surface is flush with the upper surface of the first metal reflector.

[0019] Preferably, the second dielectric support material is polyetheretherketone (PEEK), and its structure is a rotating body composed of two stacked and fixed frustums connected in series. It is positioned outside the antenna radiating element and embedded inside the first metal reflector, ensuring that its lower surface is flush with the lower surface of the first metal reflector. The rotating body has an inner diameter of 4.3 mm. The first layer is a cylinder with an outer diameter of 19.3 mm and a height of 5 mm. The second layer is a frustum with an outer diameter of 12 mm and a height of 2 mm.

[0020] Preferably, the metal sleeve pressing block is made of hard aluminum and has a hollow cylindrical structure with an outer diameter of 70 mm, an inner diameter of 36 mm, and a height of 35 mm. The metal sleeve pressing block is located outside the antenna radiating element, with three-quarters of its bottom surface in the outer radial direction and the inner radial direction pressed against the upper surface of the first metal reflector.

[0021] Preferably, the first metal reflector is made of hard aluminum, and its overall structure consists of three interconnected rings and a composite cylinder. The upper ring has an outer diameter of 92mm, and its inner diameter and thickness are the same as the outer diameter and thickness of the first dielectric support. Its bottom surface is tangent to and flush with the upper surface of the middle ring and the upper surface of the reflector base. The middle ring has an outer diameter 57mm wavelength, an inner diameter the same as the outer diameter of the first dielectric support, and a thickness of 2mm. Its lower surface is flush with the upper surface of the lower ring. The lower ring has an outer diameter of 48mm, an inner diameter of 34mm, and a thickness of 12.7mm. Its lower surface is flush with the upper surface of the composite cylinder. The composite cylinder structure is composed of a hollow frustum and a cylinder. The larger diameter of the upper surface of the hollow cylindrical platform is the same as the diameter of the lower ring, and its height is 17mm. The smaller diameter of the lower surface is the same as the outer diameter of the second-layer cylinder of the second medium support, and it is in close contact with the upper surface of the hollow cylinder. The outer diameter and height of the cylinder are the same as those of the second-layer cylinder of the second medium support.

[0022] Preferably, the parasitic inductor is made of hard aluminum, and its overall structure consists of spheres and cylinders connected vertically in a series along the axial direction. The upper end is a sphere with a diameter of 20 mm, and the lower end is a cylinder with a diameter equal to the radius of the sphere and a height of 40 mm. A total of six parasitic inductors form an array, which are fixed around the radiating inductor at 60° angles along its height axis, with a 56 mm interval between their height axes. The parasitic inductors penetrate the upper surface of the second metal reflector and are fixed to it.

[0023] Preferably, the second metal reflector is made of hard aluminum, and its overall structure is a rotating body with an inverted trapezoidal cross-section. The top (smaller) rotating surface of the trapezoid is at the same height and tangent to the outer edge of the annular structure on the first metal reflector. The bottom (larger) rotating surface of the trapezoid has a height of 55mm. The height side of the trapezoid is 57mm, and the surface formed by its rotation is tangent to and flush with the upper surface of the reflector base.

[0024] Preferably, the chassis is a disc with mounting holes, providing sufficient space to allow for the connection between the antenna radiating element and external RF connectors, and to meet the axially symmetrical series compact installation requirements of the first metal pressure block, second metal pressure block, first dielectric support, and second dielectric support. The mounting holes are located at the center of the disc, and their central axis serves as the rotation axis for the antenna radiating element, first metal pressure block, second metal pressure block, first dielectric support, and second dielectric support. The entire antenna structure is a rotating body structure, with all components sharing the same central axis with the chassis, enabling omnidirectional radiation and a more compact structure.

[0025] Preferably, the first and second dielectric support structures are made of polyetheretherketone, which has the characteristics of high pressure resistance and high and low temperature resistance. The antenna radiating element, the first metal block, the second metal block and the reflector chassis are made of hard aluminum, which can meet the performance requirements of the partial discharge measurement antenna in terms of sensitivity, frequency response and other aspects.

[0026] In the description of this invention, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "top," "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0027] It should be noted that, in this specification, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0028] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A multi-parasitic array ultra-high frequency partial discharge detection antenna, characterized in that, It comprises: an antenna radiating element, a metal sleeve clamping block, a first metal reflector, a parasitic element, a second metal reflector, a first dielectric support, a second dielectric support, and a reflective base. The antenna radiating element is an axisymmetric rotating body; the metal sleeve clamping block is located outside the antenna radiating element, with a portion of its bottom surface located on the upper surface of the first metal reflector and a portion of its bottom surface pressed against the upper surface of the first dielectric support; The first metal reflector is located outside the antenna radiator, with its outer bottom surface flush and tangent to the upper surface of the reflector base, and its bottom surface is embedded in the through hole of the reflector base. The parasitic array is symmetrically arranged around the antenna radiator along its axis and penetrates the upper surface of the second metal reflector to be fixed to it. The second metal reflector is a symmetrical rotating body along the axis of the antenna radiator, with its bottom surface flush and tangent to the upper surface of the reflector base. The inner ring surface of its rotating body is in contact with the outer surface of the first metal reflector and is distributed around the first metal reflector. The first dielectric support is a rotating annular body located outside the antenna radiator and embedded inside the first metal reflector, ensuring that its upper surface is flush with the upper surface of the first metal reflector. The second dielectric support is a rotating body located outside the antenna radiator and embedded inside the first metal reflector, ensuring that its lower surface is flush with the lower surface of the first metal reflector. The base has a first mounting through hole.

2. The multi-parasitic array ultra-high frequency partial discharge detection antenna, characterized in that, The antenna radiating element is made of hard aluminum, and its structure consists of two parts from top to bottom: a radiator and a feed element. The radiator, in its rotating form, comprises three parts from top to bottom: a coaxial radiating cylinder, a coaxial radiating extension frustum, and an impedance matching radiating ring. The coaxial radiating cylinder is connected in series with the feed element, its bottom surface tangentially connected to the top surface of the feed element. The cylinder has a diameter of 20mm and a height of 41mm. The coaxial radiating extension frustum, with a smaller diameter, has its bottom surface tangentially connected to the top surface of the coaxial radiating cylinder, and its diameter is the same as that of the coaxial radiating cylinder. The coaxial radiating extension frustum has a larger diameter, with an upper surface dimension of 78mm and a height of 25mm. The impedance matching radiating ring wraps around the outer edge of the larger diameter upper surface of the coaxial radiating extension frustum. Its inner diameter is 3mm smaller than the larger diameter of the larger upper surface of the coaxial radiating extension frustum. The outer diameter will be calculated using electromagnetic optimization to achieve the optimal antenna standing wave parameters within the antenna's operating frequency band. The feed element comprises four coaxial and serially fixed parts: an upper cylinder, a second cylinder, a frustum, and a lower cylinder. The upper cylinder is located inside the feed cylinder of the radiating element, with its bottom end flush with the bottom end of the feed cylinder of the radiating element. The second cylinder is located away from the radiating element, with its upper surface connected to the bottom end of the upper cylinder and its bottom end connected to the larger-diameter bottom surface of the frustum. The frustum is located away from the bottom end of the feed cylinder of the radiating element, with its larger-diameter top surface connected to the bottom end of the upper cylinder and its smaller-diameter bottom surface connected to the top end of the lower cylinder. The lower cylinder is located away from the radiating element, with its top surface connected to the smaller-diameter bottom surface of the frustum, and its bottom end flush with the bottom end of the dielectric sleeve and the second dielectric support, as well as flush with the upper surface of the first step of the chassis through-hole. An M3 through-hole is provided at its bottom end for connection to the RF connector.

3. The multi-parasitic array ultra-high frequency partial discharge detection antenna, characterized in that, The parasitic array is made of hard aluminum and consists of spheres and cylinders connected vertically in a series along the axial direction. The upper part is a sphere with a diameter of 20mm, and the lower part is a cylinder with a diameter equal to the radius of the sphere and a height of 40mm. A total of six parasitic arrays are arranged in an array, fixed at 60° intervals around the radiating array along its height axis. The distance between the parasitic array's height axis and the radiating array's height axis is 56mm. The parasitic arrays penetrate the upper surface of the second metal reflector and are fixed to it.

4. The multi-parasitic array ultra-high frequency partial discharge detection antenna, characterized in that, The second metal reflector is made of hard aluminum, and its overall structure is a rotating body with an inverted trapezoidal cross-section. The top (smaller) rotating surface of the trapezoid is at the same height and tangent to the outer edge of the annular structure on the first metal reflector. The bottom (larger) rotating surface of the trapezoid has a height of 55mm. The height side of the trapezoid is 57mm, and its rotating surface is tangent to and flush with the upper surface of the reflector base.

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