Non-contact sensing device for extra-high voltage direct current transmission line

Abstract

According to the non-contact sensing device used for the extra-high voltage direct current power transmission line, a probe fixing frame is arranged in an upper shell, the length of the probe fixing frame in the upper shell is not smaller than 5 cm, a probe is installed on the probe fixing frame, a lower shell is detachably connected with the upper shell, and the lower shell is detachably connected with the upper shell. An optical fiber channel inlet is formed in the lower shell, the optical fiber channel inlet is of a Y-shaped structure, the Y-shaped structure comprises a vertical section and two inclined sections obliquely extending outwards from the top of the vertical section, and an optical fiber channel outlet is communicated with the two inclined sections of the Y-shaped structure and extends into the upper shell; and a communication optical fiber extends from the vertical section of the Y-shaped structure to the inclined section, then extends out of the outlet of the optical fiber channel and is connected with the probe.

Description

Technical Field

[0001] The invention relates to the technical field of ultra-high voltage direct current transmission lines, in particular to a non-contact sensor device for ultra-high voltage direct current transmission lines. Background Art

[0002] The transmission distance of UHV DC transmission lines is long, and the topography and climate vary greatly. The requirements for rapid fault isolation, fault recovery, fault cause analysis and prevention capabilities are very high. The fault handling of transmission lines also involves cross-regional management issues. The power dispatching and operation and maintenance departments attach great importance to the distance measurement results. After a DC line fault occurs, it is usually required to provide the distance measurement results or waveform files in time as a guide for fault line inspection and auxiliary judgment of the fault type. Improving the positioning accuracy of the fault location system is conducive to improving the efficiency of fault investigation and maintenance, and improving the operation and maintenance level and reliability of transmission lines. The existing DC transmission line fault location devices are all based on the transient traveling wave principle, and the fault location is achieved through double-end ranging or single-end ranging methods. The actual operation of the device shows that the double-end ranging system has higher accuracy, the error of single-end ranging is larger, and the accuracy cannot meet the actual operation requirements. The performance of the existing voltage traveling wave sensing technology is insufficient, the dynamic characteristics are easily distorted, and the signal bandwidth is too low, which leads to unreliable startup of the fault location equipment and difficulty in setting the fixed value.

[0003] The information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0004] In view of the shortcomings or defects of the prior art, a non-contact sensing device for ultra-high voltage direct current transmission lines is provided to measure the high-frequency characteristics of the wave head, which can improve the accuracy of direct current transmission fault locating when combined with traveling wave positioning.

[0005] The purpose of the present invention is achieved through the following technical solutions.

[0006] A non-contact sensing device for an ultra-high voltage direct current transmission line comprises: Upper shell, A probe fixing frame is arranged in the upper shell, A probe, which is mounted on the probe fixing frame, a lower housing, which is detachably connected to the upper housing, The optical fiber channel inlet is arranged in the lower shell, and the optical fiber channel inlet is a Y-shaped structure, which includes a vertical section and two inclined sections extending outward from the top of the vertical section. an optical fiber channel outlet, which communicates with the two inclined sections of the Y-shaped structure and extends into the upper housing, The communication optical fiber extends from the vertical section to the inclined section of the Y-shaped structure, then extends out of the optical fiber channel outlet and connects to the probe.

[0007] In the non-contact sensing device for ultra-high voltage direct current transmission lines, the probe includes a voltage sensor to sense the measured voltage in a non-contact manner and convert it into an output signal.

[0008] In the non-contact sensor device for ultra-high voltage direct current transmission lines, the probe fixing frame is made of insulating dielectric material.

[0009] In the non-contact sensor device for an ultra-high voltage direct current transmission line, the upper shell includes a flat bottom surface and an arc-shaped surface protruding upward from the bottom surface.

[0010] In the non-contact sensor device for ultra-high voltage direct current transmission lines, the arc-shaped surface is a hemispherical surface.

[0011] In the non-contact sensing device for an ultra-high voltage direct current transmission line, the probe is located at the center of the hemispherical surface.

[0012] In the non-contact sensor device for an ultra-high voltage direct current transmission line, the probe fixing frame is connected to the upper shell by a first screw.

[0013] In the non-contact sensor device for an ultra-high voltage direct current transmission line, the lower housing is connected to the upper housing via a second screw.

[0014] In the non-contact sensor device for an ultra-high voltage direct current transmission line, a groove parallel to the vertical section is provided in the lower shell.

[0015] In the non-contact sensor device for the ultra-high voltage direct current transmission line, the non-contact sensor device has a symmetrical structure.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention adopts a non-contact sensing device for ultra-high voltage direct current transmission lines, effectively solving the problem of insufficient measurement sensitivity of current optical fiber voltage sensors to voltage refraction and reflection traveling waves under transmission line faults, and further improving the single-end ranging accuracy of the fault location system and the reliability of its ranging results. At the same time, the system has the advantages of using optical fiber to transmit traveling wave signals, saving the high cost of primary equipment, avoiding forced shutdown of DC due to coupling capacitor failure, and improving the reliability of DC transmission operation. Specifically, the probe structure and position advantages: the probe is installed in a specially designed upper shell, the upper shell has a flat bottom surface and an upwardly protruding arc surface (such as a hemispherical surface), and the probe is located at the center of the hemispherical surface. This structure makes the electric field distribution around the probe more uniform and stable, which is conducive to accurately capturing subtle changes in voltage signals. In ultra-high voltage direct current transmission lines, when a fault generates a traveling wave, the wave head contains rich high-frequency information. The probe can more keenly sense the voltage change caused by the wave head in this optimized position, thereby realizing the measurement of high-frequency characteristics. For example, compared with traditional sensors that are randomly placed or have simple structures, this probe located at the center of the sphere can reduce the signal measurement error caused by uneven electric fields and better obtain high-frequency signals.

[0017] Insulation and anti-interference guarantee: The probe holder is made of insulating dielectric material, which effectively isolates external interference. When measuring high-frequency signals, external electromagnetic interference can easily affect the measurement accuracy, and the insulating material can prevent the interference signal from entering the measurement circuit, ensuring that the probe receives a pure voltage signal caused by the wave head, thereby accurately extracting high-frequency features. At the same time, the overall symmetrical structure of the device also helps to reduce the interference caused by structural asymmetry, further ensuring the accuracy of measuring high-frequency features.

[0018] Support for fiber optic transmission: The unique Y-shaped fiber optic channel inlet and the communication fiber connected to it provide guarantee for the transmission of high-frequency signals. The optical fiber has a wide-band characteristic and can losslessly transmit the high-frequency voltage signal sensed by the probe, avoiding the problem of high-frequency information loss due to insufficient bandwidth in traditional transmission methods. From the Y-shaped fiber optic channel inlet to the optical fiber connected to the probe, a stable signal transmission path is formed, ensuring the integrity of the high-frequency signal from the probe to the subsequent processing equipment.

[0019] Signal transmission and processing coordination: When the probe measures the high-frequency characteristic signal of the wave head, the signal is quickly and accurately transmitted to the relevant fault location equipment through the optical fiber. On the equipment side, these high-frequency signals are analyzed using advanced signal processing algorithms. Since there is a certain correlation between the high-frequency characteristics of the wave head and the fault location, the location of the fault point can be determined by processing and calculating parameters such as the arrival time and amplitude change of the high-frequency signal, combined with the traveling wave positioning principle. For example, based on the speed of the high-frequency signal propagating on the transmission line and the time difference when it arrives at the probes at different positions, the fault distance can be calculated more accurately using double-ended ranging or improved single-ended ranging methods.

[0020] Data fusion and optimization: The probe measurement data of this application is fused with other possible monitoring data (such as current and other related data). In the process of fault location, the high-frequency characteristics of the voltage wave head and the changes in other electrical quantities are comprehensively considered to further optimize the fault location results. By establishing a multi-parameter fault location model, the high-frequency voltage information provided by the probe is used as one of the key inputs, and is complemented and verified with other data, the reliability and accuracy of fault location are improved. Compared with relying solely on traditional traveling wave location methods, the fault location can be judged more accurately, and the overall performance of DC power transmission fault location is improved. The above description is only an overview of the technical solution of the present invention. In order to make the technical means of the present invention clearer and to achieve the degree that those skilled in the art can implement it according to the contents of the specification, and in order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation method of the present invention is illustrated below. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] By reading the detailed description of the preferred specific embodiments below, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The drawings in the specification are only for the purpose of illustrating the preferred embodiments and are not considered to be limitations of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work. Moreover, the same reference numerals are used to represent the same components throughout the drawings.

[0022] In the attached picture: Figure 1 This is a schematic diagram of the structure of a non-contact sensor device for ultra-high voltage direct current transmission lines; Figure 2 For along Figure 1 Schematic diagram of the upper part of the middle AA line; Figure 3 For along Figure 1 Schematic diagram of the lower part of the AA line.

[0023] The present invention is further explained below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0024] The specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0025] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the attached claims.

[0026] To facilitate understanding of the embodiments of the present invention, several specific embodiments will be further explained below with reference to the accompanying drawings, and each of the accompanying drawings does not constitute a limitation on the embodiments of the present invention.

[0027] For a better understanding, Figures 1 to 3 As shown, a non-contact sensing device for ultra-high voltage direct current transmission lines comprises: Upper shell 1, The probe fixing frame 5 is arranged in the upper housing 1. The probe is mounted on the probe fixing frame 5, and the length of the probe fixing frame is not less than 90 mm to ensure that the probe is tightly mounted and the sensitivity requirements of the sensor device are met. The lower shell 2 is detachably connected to the upper shell 1. The optical fiber channel inlet 3 is arranged in the lower housing 2. The optical fiber channel inlet 3 is a Y-shaped structure, which includes a vertical section and two inclined sections extending outward from the top of the vertical section. The optical fiber channel outlet 7 is connected to the two inclined sections of the Y-shaped structure and extends into the upper housing 1. The communication optical fiber extends from the vertical section of the Y-shaped structure to the inclined section, and then extends out of the optical fiber channel outlet 7 and connects to the probe. The device adopts a unique optical fiber channel design, and the optical fiber channel inlet is a Y-shaped structure, through which the communication optical fiber is connected to the probe. This optical fiber transmission mode has the advantages of high bandwidth, low loss, and strong anti-interference ability. Different from the low signal transmission bandwidth and susceptibility to interference that may exist in the traditional voltage traveling wave sensing technology, it can quickly and accurately transmit the voltage signal sensed by the probe, ensuring the integrity and high-frequency characteristics of the signal, so that the fault location device can reliably receive high-quality signals, solving the problems of unreliable startup of the fault location device and difficulty in setting the fixed value due to the low signal bandwidth, and effectively improving the accuracy and reliability of fault location. The probe overcomes the performance defects of the existing voltage traveling wave sensing technology through the synergistic effect of structural design, insulating materials and optical fiber transmission system. In the preferred embodiment of the non-contact sensing device for ultra-high voltage direct current transmission lines, the probe includes a voltage sensor to non-contactly sense the measured voltage and convert it into an output signal.

[0028] In the preferred embodiment of the non-contact sensing device for ultra-high voltage direct current transmission lines, the probe holder 5 is made of insulating dielectric material. The probe holder is made of insulating dielectric material to effectively isolate the probe from possible interference sources in the outside world, prevent signal leakage or interference introduction due to poor insulation, ensure the purity of the signal, and avoid signal distortion. At the same time, good insulation performance also helps to maintain the stability of the electrical performance of the probe itself, which is crucial for accurately measuring voltage traveling wave signals. Compared with some sensing technologies with poor insulation performance, the reliability of measurement is improved. In the preferred embodiment of the non-contact sensing device for ultra-high voltage direct current transmission lines, the upper shell 1 includes a flat bottom surface and an arc-shaped surface protruding upward from the bottom surface.

[0029] In a preferred embodiment of the non-contact sensor device for an ultra-high voltage direct current transmission line, the arc-shaped surface is a hemispherical surface.

[0030] In a preferred embodiment of the non-contact sensing device for ultra-high voltage direct current transmission lines, the probe is located at the center of the hemispherical surface. The probe is mounted on a probe holder, which is located in an upper shell. The upper shell includes a flat bottom surface and an upwardly protruding curved surface (such as a hemispherical surface), and the probe is located at the center of the hemispherical surface, which helps to optimize the measurement environment. This design enables the probe to better capture the measured voltage signal during measurement and reduce the impact of external interference on the measurement. Compared with traditional contact or existing non-contact sensing technologies, the accuracy and stability of the measurement are improved, thereby avoiding the problem of dynamic characteristic distortion caused by a poor measurement environment. In a preferred embodiment of the non-contact sensing device for ultra-high voltage direct current transmission lines, the probe holder 5 is connected to the upper shell 1 by a first screw 6.

[0031] In a preferred embodiment of the non-contact sensor device for an ultra-high voltage direct current transmission line, the lower housing 2 is connected to the upper housing 1 via a second screw 8 .

[0032] In a preferred embodiment of the non-contact sensor device for ultra-high voltage direct current transmission lines, a groove 4 parallel to the vertical section is provided in the lower shell 2. After the groove is engaged with the support rod, additional mechanical support can be provided for the entire sensor device. In the complex environment of ultra-high voltage direct current transmission lines, it may be affected by external forces such as wind and vibration. The support rod is fixed in the lower shell through the groove, which can effectively prevent the internal components of the device from displacement or shaking, ensure that the probe, optical fiber channel and other key components are always in the correct position, maintain the integrity and stability of the device structure, and ensure the accuracy and reliability of the measurement. This interlocking structure provides convenience for positioning and fixing during the assembly process of the device. During assembly, the staff can quickly and accurately install each component based on the matching relationship between the groove and the support rod, thereby improving the assembly efficiency. At the same time, in subsequent maintenance and repair work, it is also convenient to disassemble and reinstall related components.

[0033] In the preferred embodiment of the non-contact sensing device for ultra-high voltage direct current transmission lines, the non-contact sensing device is a symmetrical structure. The entire device is a symmetrical structure, which further ensures the balance and stability of the measurement, so that the probe senses the voltage signal more consistently in all directions, reduces the signal deviation that may be caused by structural asymmetry, and helps to maintain stable dynamic characteristics. In one embodiment, the probe measures the high-frequency characteristic signal of the wave head, and the fault location device is connected to the communication optical fiber to analyze the high-frequency characteristic signal based on the signal processing algorithm to determine the location of the fault point. Since the high-frequency characteristics of the wave head are related to the fault location, the arrival time and amplitude change parameters of the high-frequency characteristic signal are processed and calculated, and the location of the fault point can be determined in combination with the traveling wave location principle. For example, according to the speed of the high-frequency characteristic signal propagating on the transmission line and the time difference of reaching the probes at different positions, the fault distance can be calculated more accurately by using a double-end ranging method or an improved single-end ranging method.

[0034] Furthermore, data fusion and optimization are performed to fuse the high-frequency characteristic signals measured by the probe with monitoring data such as current. In the process of fault location, the fault location results are optimized based on the high-frequency characteristic signals of the voltage wave head and monitoring data such as current. By establishing a multi-parameter fault location model, the high-frequency voltage information provided by the probe is used as one of the key inputs, and is complemented and verified with other data, which improves the reliability and accuracy of fault location. Compared with relying solely on traditional traveling wave location methods, it can more accurately determine the fault location and improve the overall performance of DC transmission fault location.

[0035] In one embodiment, a non-contact sensing device for an ultra-high voltage direct current transmission line includes: an upper shell 1, a lower shell 2, and a probe fixing frame 5. A probe fixing frame 5 is provided inside the upper shell 1 to place the probe, and a groove 4 and a fiber channel inlet 3 are provided inside the lower shell 2. The upper shell 1 is connected to the lower shell 2 by a second screw 8, and the interior of the upper shell 1 is connected by a first screw 6. The fiber channel inlet 3 inside the lower shell 2 is a Y-shaped structure, which is convenient for two communication optical fibers to enter and exit. The communication optical fiber enters the device through the fiber channel inlet 3, passes through the fiber channel outlet 7, enters the interior of the upper shell 1 and connects to the probe. The shell material is polytetrafluoroethylene, and the overall shape is similar to a mushroom, with a hemisphere on the top. The non-contact sensing device is fixed by a filling glue fixing method and is fixed by a fully insulating medium insulating support. The voltage sensor senses the measured voltage and converts it into a usable output signal. The non-contact sensing device used in UHV DC transmission lines can measure the high-frequency characteristics of the wave head. Combined with traveling wave positioning, it can improve the accuracy of DC transmission fault positioning, promote the popularization and application of electro-optical induction voltage sensing technology in the fields of electromagnetic environment monitoring and power equipment fault monitoring, and promote the rapid development of electromagnetic environment monitoring and power equipment status monitoring. It is of great significance to improve the technical level of traditional industries and drive technological innovation of related domestic scientific research, design, manufacturing, construction and other enterprises.

[0036] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0037] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A non-contact sensing device for ultra-high voltage direct current transmission lines, characterized in that: These include, Upper shell, A probe fixing frame is arranged in the upper shell, A probe, which is mounted on the probe fixing frame, a lower housing, which is detachably connected to the upper housing, The optical fiber channel inlet is arranged in the lower shell, and the optical fiber channel inlet is a Y-shaped structure, which includes a vertical section and two inclined sections extending outward from the top of the vertical section. an optical fiber channel outlet, which communicates with the two inclined sections of the Y-shaped structure and extends into the upper housing, The communication optical fiber extends from the vertical section to the inclined section of the Y-shaped structure, then extends out of the optical fiber channel outlet and connects to the probe.

2. The non-contact sensor device for ultra-high voltage direct current transmission line according to claim 1, characterized in that: The probe includes a voltage sensor to sense the voltage to be measured in a non-contact manner and convert it into an output signal.

3. The non-contact sensor device for ultra-high voltage direct current transmission line according to claim 1, characterized in that: The probe fixing frame is made of insulating dielectric material and has a length of not less than 90 mm, so that the measured signal meets the basic sensitivity requirements.

4. The non-contact sensor device for ultra-high voltage direct current transmission line according to claim 1, characterized in that: The upper shell includes a flat bottom surface and an arc-shaped surface protruding upward from the bottom surface.

5. The non-contact sensor device for ultra-high voltage direct current transmission line according to claim 4, characterized in that: The arc surface is a hemispherical surface.

6. The non-contact sensor device for ultra-high voltage direct current transmission line according to claim 5, characterized in that: The probe is located at the center of the hemispherical surface.

7. The non-contact sensing device for ultra-high voltage direct current transmission lines according to claim 1, characterized in that: The probe fixing frame is connected to the upper shell body through a first screw.

8. The non-contact sensor device for ultra-high voltage direct current transmission line according to claim 1, characterized in that: The lower shell is connected to the upper shell by a second screw.

9. The non-contact sensor device for ultra-high voltage direct current transmission line according to claim 1, characterized in that: A groove parallel to the vertical section is provided in the lower shell.

10. The non-contact sensor device for ultra-high voltage direct current transmission line according to claim 1, characterized in that: The non-contact sensing device has a symmetrical structure.

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