Anti-seismic test method for 500kV dry-type anti-explosion and anti-seismic transformer bushing

Abstract

The invention relates to an anti-seismic test method for a 500kV dry-type anti-explosion anti-seismic transformer bushing. The anti-seismic test method is characterized by comprising the following specific steps: the acceleration, displacement and strain of the transformer bushing are included; a natural earthquake state is simulated by adopting an anti-seismic test method designed for the anti-seismic transformer bushing; the sensor is arranged on the transformer bushing, parameter changes of the transformer bushing in a simulated earthquake state are respectively detected through the accelerometer, the displacement meter and the strain gauge, and the detection anti-seismic transformer bushing can meet the anti-seismic requirement; according to the test method disclosed by the invention, the accuracy and scientificity of an anti-seismic test result of the anti-seismic transformer bushing are improved, and a reference basis is provided for subsequent improvement of the anti-seismic transformer bushing.

Description

Technical Field

[0001] The invention relates to the technical field of earthquake-resistant transformers, and in particular to an earthquake-resistant test method for a 500kV dry-type explosion-proof and earthquake-resistant transformer bushing. Background Art

[0002] The rubber-impregnated paper capacitor transformer bushing is mainly used in AC transformers, and plays the role of current carrying, insulation and mechanical support; the main components include the general cap, head cover, insulator, connection flange, mounting flange, tail terminal, shielding and capacitor core; a 6mm rubber ring is placed between the top of the boss and the end face of the connection flange, and the axial size is matched to ensure that the boss is clamped and also plays a buffering role; in order to meet the use requirements of seismic intensity 9 in GB / T 50260, it is necessary to conduct seismic tests. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a 500kV dry-type explosion-proof and earthquake-resistant transformer bushing seismic test method, which can realize the seismic performance detection of the 500kV dry-type explosion-proof and earthquake-resistant transformer bushing.

[0004] In order to solve the above technical problems, the technical solution of the present invention is: a 500kV dry-type explosion-proof and earthquake-resistant transformer bushing seismic test method, the innovation of which lies in: the specific seismic test method is as follows: including the acceleration, displacement and strain of the transformer bushing; S1: Installation and fixation of the specimen: Install the transformer seismic bushing on the ground with a test angle of 3° to the vertical direction; S2: Specimen arrangement and measurement point arrangement: Prepare several sensors, including accelerometers, displacement gauges and strain gauges; Acceleration measurement points are arranged at the table (MAT), top of hollow composite insulator (MA1), 1 / 2 of hollow composite insulator (MA2), top of mounting flange (MA3), top of bracket (MA4) and bottom of hollow composite insulator (MA5), totaling 6 measurement points; each measurement point should be arranged as a three-way sensor (-X, -Y, -Z), with a total of 18 acceleration channels; displacement measurement points are arranged at 3 measurement points, including the bottom of hollow composite insulator (MD1), top of bracket (MD2) and top of hollow composite insulator (MD3), each measurement point only measures the displacement in the vibration direction, with a total of 3 displacement channels; strain measurement points are arranged at the root of hollow composite insulator (MS1), 1 / 4 of hollow composite insulator (MS2), 1 / 2 of hollow composite insulator (MS3), mounting flange (MS4), rib plate (MS5), totaling 16 strain channels; S3: Test conditions and experimental methods: The ratio of artificial wave X-direction PGA to Z-direction PGA is 0.6; white noise and artificial waves are used to simulate seismic waves; before and after each artificial wave test, white noise sweep frequency range is 0-50Hz, acceleration peak is 0.1g, and duration is 70s; artificial wave is an acceleration time-history wave fitted according to the test response spectrum damping ratio ξ=2%; including artificial wave time history input in X direction and artificial wave time history input in Z direction; the artificial wave of each condition is modulated according to the acceleration peak of the condition and the dynamic amplification factor of the bracket, and then used as the table input for seismic test.

[0005] The advantages of the present invention are: 1) In the present invention, a seismic test method designed for seismic-resistant transformer bushings is adopted to simulate natural earthquake conditions; a sensor is arranged on the transformer bushing, and parameter changes of the transformer bushing under the simulated earthquake condition are respectively detected by an accelerometer, a displacement meter and a strain gauge, so as to detect whether the seismic-resistant transformer bushing can meet the seismic requirements; the test method of the present invention improves the accuracy and scientificity of the seismic test results of the seismic-resistant transformer bushings, and provides a reference basis for the subsequent improvement of the seismic-resistant transformer bushings. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0007] Figure 1 The present invention provides a measurement point arrangement diagram for a 500kV dry-type explosion-proof and earthquake-resistant transformer bushing earthquake resistance test method.

[0008] Figure 2 The invention discloses a test response spectrum for a 500kV dry-type explosion-proof and earthquake-resistant transformer bushing earthquake-resistant test method.

[0009] Figure 3 The invention discloses an X-direction artificial wave acceleration time history for testing a 500kV dry-type explosion-proof and earthquake-resistant transformer bushing earthquake-resistant test method.

[0010] Figure 4 The invention discloses a Z-direction artificial wave acceleration time history for testing a 500kV dry-type explosion-proof and earthquake-resistant transformer bushing earthquake-resistant test method. DETAILED DESCRIPTION

[0011] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0012] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0013] like Figures 1 to 4 A 500kV dry-type explosion-proof and earthquake-resistant transformer bushing seismic test method is shown, and the specific seismic test method is as follows: including acceleration, displacement and strain of the transformer bushing.

[0014] S1: Installation and fixation of the specimen: Install the transformer seismic bushing on the ground with a test angle of 3° to the vertical direction.

[0015] S2: Specimen arrangement and measuring point arrangement: Prepare several sensors, including accelerometers, displacement gauges and strain gauges; Acceleration measuring points are arranged at table top (MAT), top of hollow composite insulator (MA1), 1 / 2 of hollow composite insulator (MA2), top of mounting flange (MA3), top of bracket (MA4) and bottom of hollow composite insulator (MA5), totaling 6 measuring points; Each measuring point should be arranged as a three-way sensor (-X, -Y, -Z), with a total of 18 acceleration channels; Displacement measuring points are arranged at 3 measuring points, including bottom of hollow composite insulator (MD1), top of bracket (MD2) and top of hollow composite insulator (MD3), each measuring point only measures displacement in the vibration direction, with a total of 3 displacement channels; Strain measuring points are arranged at root of hollow composite insulator (MS1), 1 / 4 of hollow composite insulator (MS2), 1 / 2 of hollow composite insulator (MS3), mounting flange (MS4), rib (MS5), totaling 16 strain channels.

[0016] S3: Test conditions and experimental methods: The test conditions are shown in Table 5.3-1; the ratio of artificial wave X-direction PGA to Z-direction PGA is 0.6; white noise and artificial waves are used to simulate seismic waves; before and after each artificial wave test, white noise sweep frequency range is 0-50Hz, acceleration peak is 0.1g, and duration is 70s; artificial waves are acceleration time-history waves fitted according to the test response spectrum damping ratio ξ=2%; including artificial wave time history input in X direction and artificial wave time history input in Z direction; artificial waves in each condition are modulated according to the acceleration peak of the condition and the dynamic amplification factor of the bracket, and then used as table input for seismic test.

[0017] The vibration table laboratory is carried out on the MTS6.1m×6.1m earthquake simulation vibration table. The main technical indicators of the system are shown in Table 4.1-1; The test data of the test piece is acquired using the data acquisition system of NI Company, with 128 channels and a sampling frequency of 100Hz-100kHz. The acceleration sensor model is Lance accelerometer, with a range of ±5g; the strain is tested using 1 / 4 bridge; Artificial wave vibration table tests were conducted under the conditions of 0.1g×2, 0.2g×2 and 0.4g×2. Tables 6.2-1 to 6.2-3 show the peak acceleration of the test pieces under each condition; Tables 6.2-4 to 6.2.6 show the peak strain of the test pieces under each condition; Tables 6.2-7 to 6.2-9 show the peak displacement of the test pieces under each condition. The calculated peak relative displacement between the top and the table of the hollow composite insulator is 88.100mm.

[0018] According to the strain test results, the stress is calculated as follows: Where: is the stress calculated according to the measured strain (MPa); is the elastic modulus; is the measured strain value of the measuring point; is the spectrum correction coefficient; According to the Code for Seismic Design of Power Facilities (GB 50260-2013) and the test plan provided by the client, the load effect combined stress of the test piece should include the seismic action of the structure, 0.25 times the design wind load, 0.75 times the terminal tension, internal pressure of the equipment, etc.

[0019] The safety factor of the test hollow composite insulator is as follows: It can be seen from Table 6.2-6 that the maximum strain of the hollow composite insulator under the 0.4g×2 (X+Z) working condition is located at the root of its X direction, which is 1546με. According to the elastic modulus of the hollow composite insulator provided by the client, 18Gpa, and the spectrum correction coefficient is 1, the stress of the earthquake action is calculated to be 27.83Mpa according to formula (6.2-1). The maximum strain of the mounting flange under the 0.4g×2 working condition is located at the root of the rib plate in the X direction, which is 992με; the elastic modulus of the mounting flange is 70Gpa, and the spectrum correction coefficient is 1; the calculated stress of the earthquake action is 69.44Mpa.

[0020] The wind load stress at the root of the hollow composite insulator is 3.53Mpa, the internal pressure stress is 0MPa, The terminal tensile stress is 4.89Mpa, the wind load stress at the mounting flange is 1.51Mpa, the internal pressure stress is 0MPa, and the terminal tensile stress is 2.08Mpa. The combined stress of the hollow composite insulator is 31.65Mpa, and the combined stress of the mounting flange is 71.08Mpa.

[0021] The breaking stress of the hollow composite insulator is 105MPa, and the safety factor of the hollow composite insulator calculated by formula (6.2-2) is 3.32. The yield strength of the mounting flange is 125MPa, and the stress of the mounting flange is 0.57 of its yield strength.

[0022] The safety factors of the main components of the test sample under 0.4g×2 working condition (X+Z) are listed in Table 6.2-10: The elastic modulus (18GPa) and breaking stress (105MPa) of hollow composite insulators, the elastic modulus (70Gpa) and yield strength (125MPa) of mounting flanges, and the stress and relative displacement caused by wind load groups, internal pressure and terminal tension at the corresponding parts, the safety factor of the root of the hollow composite insulator of the specimen after considering the action combination is 3.32 in the 0.4g×2 (factor 2 is the dynamic amplification factor) working condition (X+Z) vibration table test, which meets the requirement of 1.67. The mounting flange stress is 0.57 of its yield strength, which meets the requirement of not exceeding 0.90. The peak displacement of the top of the hollow composite insulator relative to the table surface after the combination is 88.100mm.

[0023] The white noise sweep frequency test showed that the basic frequency was 3Hz before the earthquake test, and the basic frequencies were 3.375Hz, 3.375Hz and 3.25Hz respectively after the test, with no significant change. After the test piece was subjected to the 0.4g×2 (X+Z) working condition, the appearance inspection showed no abnormality, and there was no obvious leakage after on-site inspection.

[0024] The specimen passed the seismic mechanical properties test under 0.4g×2 (X+Z) working condition.

[0025] Those skilled in the art should understand that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and improvements, and these changes and improvements shall all fall within the scope of the present invention claimed for protection.

Claims

1. A 500kV dry-type explosion-proof and earthquake-resistant transformer bushing seismic test method, characterized in that: The specific seismic test methods are as follows: including acceleration, displacement and strain of transformer bushing; S1: Installation and fixation of the specimen: Install the transformer seismic bushing on the ground with a test angle of 3° to the vertical direction; S2: Specimen arrangement and measurement point arrangement: Prepare several sensors, including accelerometers, displacement gauges and strain gauges; Acceleration measurement points are arranged at the table (MAT), top of hollow composite insulator (MA1), 1 / 2 of hollow composite insulator (MA2), top of mounting flange (MA3), top of bracket (MA4) and bottom of hollow composite insulator (MA5), totaling 6 measurement points; each measurement point should be arranged as a three-way sensor (-X, -Y, -Z), with a total of 18 acceleration channels; displacement measurement points are arranged at 3 measurement points, including the bottom of hollow composite insulator (MD1), top of bracket (MD2) and top of hollow composite insulator (MD3), each measurement point only measures the displacement in the vibration direction, with a total of 3 displacement channels; strain measurement points are arranged at the root of hollow composite insulator (MS1), 1 / 4 of hollow composite insulator (MS2), 1 / 2 of hollow composite insulator (MS3), mounting flange (MS4), rib plate (MS5), totaling 16 strain channels; S3: Test conditions and experimental methods: The ratio of artificial wave X-direction PGA to Z-direction PGA is 0.6; white noise and artificial waves are used to simulate seismic waves; before and after each artificial wave test, white noise sweep frequency range is 0-50Hz, acceleration peak is 0.1g, and duration is 70s; artificial wave is an acceleration time-history wave fitted according to the test response spectrum damping ratio ξ=2%; including artificial wave time history input in X direction and artificial wave time history input in Z direction; the artificial wave of each condition is modulated according to the acceleration peak of the condition and the dynamic amplification factor of the bracket, and then used as the table input for seismic test.

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