Method and device for testing strength of three-post insulator assembly process of GIL (Gas Insulated Line) equipment

Abstract

The invention discloses a GIL equipment three-post insulator assembling process strength testing method and device, and the method comprises the steps: firstly dividing a detection region, taking an annular platform region, corresponding to the peripheral side of an embedded cylinder, of a body as a first detection region, and taking an outer side wall region, far away from the first detection region, of the body as a second detection region; fBG sensors are arranged in the first detection area and the second detection area respectively, and the FBG sensors in the first detection area are optical fiber multi-grating sensors and are arranged in a double-circle mode. The fiber bragg grating sensor in the second detection area is a fiber bragg grating strain rosette sensor; the optical fiber multi-grating sensor in the first detection area and the optical fiber grating strain rosette sensor in the second detection area are respectively connected with an external optical fiber grating demodulator, and the optical fiber grating demodulator is in communication connection with an upper computer and collects and stores sampling data of the first detection area and the second detection area through matching software of the upper computer; finally, analysis and evaluation are completed, and mechanical performance or stress-strain state measurement and evaluation under the typical assembly load are achieved.

Description

Technical Field

[0001] This invention belongs to the field of high-voltage electrical equipment testing technology, specifically relating to a method and apparatus for strength testing during the assembly process of three-post insulators in GIL equipment. Background Technology

[0002] Gas-insulated transmission lines (GILs) are high-voltage, high-current power transmission equipment that uses SF6 gas or an SF6 / N2 mixture for insulation, with the conductor and metal enclosure arranged coaxially. They have broad development and application prospects. The three-post insulator is a crucial component of the GIL, supporting the internal conductor and isolating the high-voltage conductor from the low-voltage enclosure. Its mechanical properties are key factors for the long-term stable operation of the GIL, and the mechanical strain generated during assembly, especially during crimping, is one of the inducing factors for three-post insulator failures.

[0003] Currently, the mechanical performance testing of three-post insulators usually involves measuring their breaking strength under typical loads (such as applying tension or bending moment to the legs). In terms of testing technology, resistance strain gauges are the main technical means for strain measurement of three-post insulators. Ultrasonic testing has also been reported to be applied to the strength testing of three-post insulators. However, existing technologies are difficult to measure and evaluate the mechanical performance or stress-strain state under typical assembly loads, and the distributed testing capabilities and environmental adaptability of testing technologies are also insufficient.

[0004] Therefore, how to provide a testing method and device that can effectively measure strain state and assess strength under typical assembly loads, and improve the mechanical strength testing and analysis capabilities of three-post insulators, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a strength testing device and method for the assembly process of three-post insulators in GIL (Gas Insulator Line) equipment. The assembly process refers to the assembly and transportation of GILs, including crimping, insertion into the cylinder, rotation, and transportation. This method can effectively measure the strain state and assess the strength under typical assembly loads, improving the mechanical strength testing and analysis capabilities of three-post insulators. It has significant economic value for the early detection of defects and the long-term safe operation of GILs.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a strength testing method for the assembly process of a three-post insulator in a GIL device, wherein the three-post insulator includes a body and three posts extending radially from the outer contour of the body, and includes the following steps: Step 1: Divide the detection area. The perforation of the three-post insulator body is provided with an inner tube for fixing the current-carrying conductor. The annular platform area on the periphery of the body corresponding to the inner tube is the first detection area, and the outer wall area of ​​the body away from the first detection area is the second detection area. Step 2: Arrange fiber Bragg grating sensors in the first detection area and the second detection area respectively. The fiber Bragg grating sensors in the first detection area are fiber multi-grating sensors arranged in a double-ring layout. The fiber grating sensor in the second detection area is a fiber grating strain gauge sensor. According to the assembly process and testing requirements, fiber grating strain gauge sensors are arranged at different positions in the second detection area to achieve plane strain testing. Step 3: Apply typical assembly loads during the assembly process to the three-post insulator using an external loading device; Step 4: Data acquisition. Connect the fiber optic multi-grating sensor in the first detection area and the fiber optic strain gauge sensor in the second detection area to an external fiber optic demodulator. The fiber optic demodulator is connected to a host computer and acquires and stores the sampling data of the first and second detection areas through the matching software of the host computer. Step 5: Analysis and evaluation. The host computer software draws time-strain curves at different test locations during the assembly process, extracts the maximum strain and final mechanical strain of each assembly process, and performs strength analysis to achieve measurement and evaluation of mechanical performance or stress-strain state under typical assembly loads.

[0007] The beneficial technical effects of this invention are as follows: by rationally dividing the detection area on the three-post insulator and rationally arranging fiber optic grating sensors in the detection area, and obtaining stress and strain data of the three-post insulator assembly process based on the detection data, the typical assembly load is to apply a load to a specific position of the product under test to achieve strength testing of typical areas, making it easy to analyze the stress performance of the product. By specifically arranging the strain sensors in the first and second detection areas, the load strain state of the area can be accurately obtained, which can effectively realize strain state measurement and strength evaluation under typical assembly load, and improve the mechanical strength testing and analysis capabilities of the three-post insulator.

[0008] Preferably, in step one, the outer contour of the first detection area is 6mm to 8mm away from the edge of the perforation.

[0009] Preferably, in step two, the fiber optic multi-grating sensor is arranged in the first detection area to form a first detection ring and a second detection ring, and the fiber optic multi-grating sensor of the first detection ring is 2mm away from the inner wall of the perforation.

[0010] The resulting technical effect is that the dual-ring fiber optic multi-grating sensor can measure regional strain at multiple points with high precision, which facilitates the accurate acquisition of regional strength test data and subsequent strength analysis and evaluation.

[0011] Preferably, the gratings of the fiber optic multi-grating sensor in the first detection ring are arranged at 30° intervals in the circumferential direction, and the fiber optic multi-grating sensor in the second detection ring is arranged 4mm away from the inner wall of the perforation. The gratings of the fiber optic multi-grating sensor in the second detection ring are arranged at 30° intervals in the circumferential direction, and there is a 15° misalignment angle between the gratings of the first detection ring and the second detection ring in the circumferential direction.

[0012] The resulting technical effect is that the first and second detection rings are arranged in an inner and outer double-ring configuration, with the sensor gratings corresponding to the inner and outer rings circumferentially staggered to facilitate the acquisition of strain data in the region from multiple points, thus providing a more accurate reflection of the load strain state in the region.

[0013] Preferably, the gratings of the fiber optic multi-grating sensor in the first detection ring are arranged at 30° intervals in the circumferential direction, and the second detection ring is a wavy ring. The gratings corresponding to the second detection ring overlap with the gratings corresponding to the first detection ring and are offset by 30°.

[0014] The resulting technical effect is that, unlike the above arrangement, the detection positions of the first and second detection rings overlap, but the arrangement directions of the sensor gratings are reversed to obtain strain data in different directions.

[0015] Preferably, in step five, the strength analysis is achieved using a high-stress zone analysis method based on numerical models and test data; The high-stress zone analysis method based on numerical models and test data involves simulating the assembly process through numerical analysis, applying assembly loads in the finite element model, calculating the global stress-strain distribution of the three-post insulator, correcting the assembly loads to make the strain response at the test point consistent with the test data, and extracting the maximum stress-strain value from the numerical model.

[0016] Preferably, the numerical model is a finite element model of a three-post insulator; The finite element model described above is designed using substructure modeling technology and meridional element partitioning technology; The substructure modeling technique described above involves finite element mesh generation for epoxy casting model parts. First, the substructure method is used to separate the irregular model in the low-stress horizontal zone and the regular model in the high-stress zone. A cylindrical substructure is established in the connection area with the inner cylinder. Hexahedral mesh and meridional element generation techniques are used to control the element generation quality in the high-stress zone. The remaining parts of the casting part are analyzed using the more adaptable tetrahedral element method.

[0017] The resulting technical effect is that the strength analysis, with the help of the finite element model, compensates for the observation and analysis of stress areas that cannot be tested through data inversion. It can effectively realize the measurement of strain state and strength assessment under typical assembly loads, and improve the mechanical strength testing and analysis capabilities of three-post insulators.

[0018] This invention also discloses an apparatus for strength testing during the assembly process of the three-post insulator of the above-mentioned GIL equipment, comprising: a fiber Bragg grating sensor, a fiber Bragg grating demodulator, and a host computer. The fiber Bragg grating sensor is arranged in both the first and second detection areas of the three-post insulator. The fiber Bragg grating demodulator is connected to the fiber Bragg grating sensor via a wire and is used to measure and analyze the fiber Bragg grating sensor signal. The host computer is communicatively connected to the fiber Bragg grating demodulator and sets sampling parameters and stores sampling data based on software.

[0019] Preferably, the fiber Bragg grating sensor is a bare fiber multi-grating sensor or a fiber Bragg grating strain gauge sensor. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the sensor layout in the first detection area of ​​a strength testing method for the assembly process of a three-post insulator in a GIL device according to the present invention. Figure 2 This is a schematic diagram of the sensor layout in the first detection area of ​​a strength testing method for the assembly process of a three-post insulator in a GIL device according to the present invention. Figure 3 This is a schematic diagram illustrating the division of the first and second detection areas in a strength testing method for the assembly process of a three-post insulator in a GIL device according to the present invention. Figure 4 This is a schematic diagram illustrating the high-stress zone analysis of a three-post insulator in a GIL device, provided by the present invention.

[0021] 1. Body, 2. Support column, 3. Inner tube, 4. First detection area, 5. Second detection area, 6. First detection ring, 7. Second detection ring. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] See the appendix of this invention. Figures 1 to 4 According to an embodiment of the present invention, a method for strength testing during the assembly process of a three-post insulator for GIL equipment is provided, wherein the three-post insulator includes a body 1 and three posts 2 extending radially from the outer contour of the body, as shown in the attached figure. Figure 3 The simulated structure includes the following steps: Step 1: Divide the detection area. The perforation of the three-post insulator body is provided with an inner cylinder 3 for fixing the current-carrying conductor. The annular platform area on the side of the body 1 corresponding to the inner cylinder 3 is the first detection area 4, and the outer wall area of ​​the body 1 away from the first detection area 4 is the second detection area 5. Step 2: Arrange fiber Bragg grating sensors in the first detection area 4 and the second detection area 5 respectively. The fiber Bragg grating sensors in the first detection area 4 are fiber multi-grating sensors and are arranged in a double-ring layout. The fiber grating sensor in the second detection area 5 is a fiber grating strain rosette sensor. According to the assembly process and testing requirements, fiber grating strain rosette sensors are arranged at different positions in the second detection area to realize plane strain testing. The second detection area has enough space to use strain rosette sensors to realize plane strain testing. Step 3: Apply typical assembly loads during the assembly process to the three-post insulator using an external loading device; Step 4: Data acquisition. Connect the fiber optic multi-grating sensor in the first detection area 4 and the fiber optic strain gauge sensor in the second detection area 5 to the external fiber optic demodulator. The fiber optic demodulator is connected to the host computer and the sampling data of the first and second detection areas are acquired and stored through the matching software of the host computer. Step 5: Analysis and evaluation. The host computer software draws time-strain curves at different test locations during the assembly process, extracts the maximum strain and final mechanical strain of each assembly process, and performs strength analysis to achieve measurement and evaluation of mechanical performance or stress-strain state under typical assembly loads.

[0024] Specifically, in step one, the outer contour of the first detection area 4 is 6mm~8mm away from the edge of the perforation.

[0025] More specifically, in step two, the fiber optic multi-grating sensor is arranged in the first detection area to form a first detection ring 6 and a second detection ring 7, with the fiber optic multi-grating sensor of the first detection ring 6 2mm away from the inner wall of the perforation.

[0026] The detection rings in the first detection area have at least two possible layouts. The first is a double-ring layout, with the fiber optic multi-grating sensor's gratings in the first detection ring 6 spaced 30° apart circumferentially and 2mm from the inner wall of the perforation. The fiber optic multi-grating sensor in the second detection ring 7 is positioned 4mm from the inner wall of the perforation, with its gratings also spaced 30° apart circumferentially. Correspondingly, the gratings in the first and second detection rings have a 15° circumferential misalignment. (See attached diagram.) Figure 1 .

[0027] The second type is a stacked ring cross layout. In the first detection ring 6, the fiber optic multi-grating sensor's gratings are spaced 30° apart circumferentially and 2mm away from the perforation. The second detection ring 7 is a wavy ring, with the gratings corresponding to the second detection ring overlapping with those corresponding to the first detection ring at a 30° offset angle. See the appendix for details. Figure 2 .

[0028] Specifically, in step five, the strength analysis is achieved using a high-stress zone analysis method based on numerical models and test data; The high-stress zone analysis method based on numerical models and test data involves simulating the assembly process through numerical analysis, applying assembly loads in the finite element model, calculating the global stress-strain distribution of the three-post insulator, correcting the assembly loads to make the strain response at the test point consistent with the test data, and extracting the maximum stress-strain value from the numerical model.

[0029] Data consistency is defined as the least squares error between the calculated and measured values ​​being less than 10%.

[0030] The numerical model is a finite element model of a three-post insulator; The finite element model employs local fine-grained modeling techniques such as substructure and meridional element division, and the Abqus finite element software can be used optionally. The substructure modeling technique described above involves finite element mesh generation for epoxy casting model parts. First, the substructure method is used to separate the irregular model in the low-stress horizontal zone and the regular model in the high-stress zone. A cylindrical substructure is established in the connection area with the inner cylinder. Hexahedral mesh and meridional element generation techniques are used to control the element generation quality in the high-stress zone. The remaining parts of the casting part are analyzed using the more adaptable tetrahedral element method.

[0031] This invention also discloses an apparatus for strength testing during the assembly process of the above-mentioned GIL equipment three-post insulator, comprising: a fiber Bragg grating sensor, a fiber Bragg grating demodulator, and a host computer. The fiber Bragg grating sensor is arranged in both the first and second detection areas of the three-post insulator. The fiber Bragg grating demodulator is connected to the fiber Bragg grating sensor via a wire and is used to measure and analyze the fiber Bragg grating sensor signal. The host computer is communicatively connected to the fiber Bragg grating demodulator and sets sampling parameters and stores sampling data based on software.

[0032] The fiber Bragg grating sensor is a fiber multi-grating sensor or a fiber Bragg grating strain gauge sensor, and optionally a fiber Bragg grating sensor.

[0033] Fiber Bragg grating sensor design includes the design of grating length and grating spacing for bare fiber multi-grating sensors; The grating length is limited by the size of the test structure and must be no less than 2mm. The grating spacing is designed based on the distance between the measurement points and their relative angles, and the fiber bending radius must be no less than 15mm.

[0034] The apparatus and methods disclosed in the embodiments are described simply because they correspond to the methods disclosed in the embodiments. For relevant details, please refer to the method section.

[0035] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for strength testing during the assembly process of a three-post insulator for GIL equipment, wherein the three-post insulator includes a body (1) and three posts (2) extending radially from the outer contour of the body, characterized in that, Includes the following steps: Step 1: Divide the detection area. The perforation of the three-post insulator body is provided with an inner tube (3) for fixing the current-carrying conductor. The annular platform area on the periphery of the body (1) corresponding to the inner tube (3) is the first detection area (4). The outer wall area of ​​the body (1) away from the first detection area (4) is the second detection area (5). Step 2: Arrange fiber optic grating sensors in the first detection area (4) and the second detection area (5) respectively. The fiber optic grating sensor in the first detection area (4) is a fiber multi-grating sensor and is arranged in a double-ring layout. The fiber grating sensor in the second detection area (5) is a fiber grating strain gauge sensor. According to the assembly process and testing requirements, fiber grating strain gauge sensors are arranged at different positions in the second detection area to achieve plane strain testing. Step 3: Apply typical assembly loads during the assembly process to the three-post insulator using an external loading device; Step 4: Data acquisition. Connect the fiber optic multi-grating sensor in the first detection area (4) and the fiber optic strain gauge sensor in the second detection area (5) to the external fiber optic demodulator. The fiber optic demodulator is connected to the host computer and the sampling data of the first and second detection areas are acquired and stored through the matching software of the host computer. Step 5: Analysis and evaluation. The host computer software draws time-strain curves at different test locations during the assembly process, extracts the maximum strain and final mechanical strain of each assembly process, and performs strength analysis to achieve measurement and evaluation of mechanical performance or stress-strain state under typical assembly loads.

2. The method for strength testing during the assembly process of a three-post insulator for GIL equipment according to claim 1, characterized in that, In step one, the outer contour of the first detection area (4) is 6mm~8mm away from the edge of the perforation.

3. The method for strength testing during the assembly process of a three-post insulator for GIL equipment according to claim 1, characterized in that, In step two, the fiber optic multi-grating sensor is arranged in the first detection area to form a first detection ring (6) and a second detection ring (7), and the fiber optic multi-grating sensor of the first detection ring (6) is 2mm away from the inner wall of the perforation.

4. The method for strength testing during the assembly process of a three-post insulator for GIL equipment according to claim 3, characterized in that, The fiber optic multi-grating sensor of the first detection ring (6) is arranged with gratings spaced 30° apart in the circumferential direction. The fiber optic multi-grating sensor of the second detection ring (7) is arranged 4mm away from the inner wall of the perforation. The gratings of the fiber optic multi-grating sensor of the second detection ring (7) are arranged with gratings spaced 30° apart in the circumferential direction. The gratings of the first detection ring and the second detection ring are misaligned by 15° in the circumferential direction.

5. The method for strength testing during the assembly process of a three-post insulator for GIL equipment according to claim 3, characterized in that, The fiber optic multi-grating sensor of the first detection ring (6) has gratings arranged at 30° intervals in the circumferential direction. The second detection ring (7) is a wavy ring. The gratings corresponding to the second detection ring (7) overlap with the gratings corresponding to the first detection ring and have a 30° offset angle.

6. The method for strength testing during the assembly process of a three-post insulator for GIL equipment according to claim 1, characterized in that, In step five, the strength analysis is achieved using a high-stress zone analysis method based on numerical models and test data. The high-stress zone analysis method based on numerical models and test data involves simulating the assembly process through numerical analysis, applying assembly loads in the finite element model, calculating the global stress-strain distribution of the three-post insulator, correcting the assembly loads to make the strain response at the test point consistent with the test data, and extracting the maximum stress-strain value from the numerical model.

7. The method for strength testing during the assembly process of a three-post insulator for GIL equipment according to claim 6, characterized in that, The numerical model described is a finite element model of a three-post insulator; The finite element model described above is designed using substructure modeling technology and meridional element partitioning technology; The substructure modeling technique described above involves finite element mesh generation for epoxy casting model parts. First, the substructure method is used to separate the irregular model in the low-stress horizontal zone and the regular model in the high-stress zone. A cylindrical substructure is established in the connection area with the inner cylinder. Hexahedral mesh and meridional element generation techniques are used to control the element generation quality in the high-stress zone. The remaining parts of the casting part are analyzed using the more adaptable tetrahedral element method.

8. An apparatus used in the strength testing method for the assembly process of three-post insulators of GIL equipment as described in any one of claims 1-7, characterized in that, include: The fiber Bragg grating sensor, fiber Bragg grating demodulator, and host computer are provided. The fiber Bragg grating sensor is arranged in both the first and second detection areas of the three-post insulator. The fiber Bragg grating demodulator is connected to the fiber Bragg grating sensor through a wire and is used to measure and analyze the fiber Bragg grating sensor signal. The host computer is communicatively connected to the fiber Bragg grating demodulator and sets sampling parameters and stores sampling data based on software.

9. A strength testing device for the assembly process of a three-post insulator in a GIL device according to claim 8, characterized in that, The fiber optic grating sensor is a fiber optic multi-grating sensor or a fiber optic strain gauge sensor.

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