Device and method for evaluating arc extinguishing characteristic of multi-gap lightning arrester

Abstract

The invention discloses a device and a method for evaluating the arc extinguishing characteristic of a multi-gap lightning arrester. The device comprises a test platform, an impulse current generator, a voltage measuring probe, a current measuring coil, an image shooting unit and a control and measurement system, the test platform is used for being connected with the multi-gap lightning arrester, and the impulse current generator, the current measuring coil and the voltage measuring probe are all connected with the test platform and the control and measurement system. The multi-gap lightning arrester arc extinguishing characteristic evaluation method based on magnetohydrodynamics is provided for the first time, the current situation that existing multi-gap lightning arrester performance evaluation lacks scientific basis is changed, and support is provided for multi-gap lightning arrester performance evaluation.

Description

Technical Field

[0001] The present invention belongs to the technical field of lightning protection for transmission lines in petrochemical industry, and particularly relates to an evaluation device and method for the arc extinguishing characteristics of a multi-gap lightning arrester. Background Art

[0002] Installing a line lightning arrester is an effective means to improve the lightning protection level of a transmission line. The multi-gap lightning arrester has multiple arc ejection holes and can efficiently extinguish the lightning current arc. After the multi-gap lightning arrester breaks down, it ejects an arc magnetohydrodynamic fluid, and its arc extinguishing characteristic law conforms to the principles of magnetohydrodynamics.

[0003] The existing performance characterization methods for multi-gap lightning arresters do not consider the basic principles of magnetohydrodynamics, fail to obtain the characteristic law of arc magnetohydrodynamics, and do not combine magnetohydrodynamics with the arc extinguishing characteristic parameters of multi-gap lightning arresters. Only type tests such as lightning impulse and high-current withstand are carried out on multi-gap lightning arresters, and the arc extinguishing performance of multi-gap arc ejection holes cannot be reflected. The present invention proposes an experimental device and method for evaluating the arc extinguishing characteristics of multi-gap lightning arresters, and obtains the changing characteristics of arc magnetohydrodynamics during the arc extinguishing process of multi-gap lightning arresters, so as to provide a basis for the structural research and development of multi-gap lightning arresters. Summary of the Invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention proposes an evaluation device and method for the arc extinguishing characteristics of a multi-gap lightning arrester, which is reasonably designed, overcomes the deficiencies of the prior art, and has good effects.

[0005] In order to achieve the above object 1, the present invention adopts the following technical solution:

[0006] An evaluation device for the arc extinguishing characteristics of a multi-gap lightning arrester includes a test platform, an impulse current generator, a voltage measurement probe, a current measurement coil, an image capturing unit, and a control and measurement system; the test platform is used to connect the multi-gap lightning arrester, and the impulse current generator, the current measurement coil, the voltage measurement probe, and the image capturing unit are all connected to the test platform and the control and measurement system.

[0007] Further, the image capturing unit is a high-speed camera.

[0008] Further, the distance between the high-speed camera and the test platform is 5 m.

[0009] Further, the control and measurement system includes an oscilloscope and a computer, and the oscilloscope is connected to the current measurement coil and the voltage measurement probe.

[0010] Further, the multi-gap lightning arrester belongs to a lightning arrester for 110 kV power transmission and distribution lines and is installed between the phase line and the ground.

[0011] In order to achieve the above object 2, the present invention adopts the following technical solution:

[0012] A method for evaluating the arc extinguishing characteristics of a multi-gap lightning arrester, using a device for evaluating the arc extinguishing characteristics of a multi-gap lightning arrester as described above, includes the following steps:

[0013] S1. Set up a device for evaluating the arc extinguishing characteristics of a multi-gap lightning arrester, connect the multi-gap lightning arrester to be tested to the test platform, and set the charging voltage and impulse current;

[0014] S2. The impulse current generator generates impulse current waves with different waveforms and amplitudes. When the impulse current flows through the multi-gap lightning arrester, a jet-shaped arc magnetohydrodynamic is generated;

[0015] S3. The high-speed camera captures the high-speed motion state of the arc magnetohydrodynamic and transmits it to the control and measurement system, calculates the jet velocity of the arc magnetohydrodynamic, performs image calibration and post-processing on the captured arc jet photos, and calculates the temperature change characteristics of the arc based on the dual-wavelength two-color temperature measurement method;

[0016] S4. The voltage probe obtains the residual voltage of the multi-gap lightning arrester, and the current measurement coil obtains the impulse current, and transmits them to the oscilloscope. The oscilloscope collects and records them, and then transmits them to the control and measurement system.

[0017] Further, the acquisition speed of the high-speed camera is more than 10,000 frames per second.

[0018] Further, compare the obtained jet velocity, residual voltage, and temperature of the arc magnetohydrodynamic with relevant standards and literature to evaluate the arc extinguishing characteristics of the multi-gap lightning arrester.

[0019] Further, the impulse current generator can generate impulse current waves with waveforms of 8 / 20 μs, 4 / 10 μs, 10 / 350 μs, 30 / 80 μs and amplitudes of 0 - 200 kA.

[0020] Further, the jet velocity expression is:

[0021] V = L×10 -3 / t;

[0022] Wherein, V is the jet velocity, with the unit of m / s;

[0023] L is the upward ejection distance of the arc, with the unit of mm;

[0024] t is the ejection time, with the unit of s.

[0025] The beneficial technical effects brought by the present invention:

[0026] (1) The present invention first proposes a method for evaluating the arc extinguishing characteristics of a multi-gap lightning arrester based on magnetohydrodynamics, changing the current situation that the performance evaluation of existing multi-gap lightning arresters lacks a scientific basis.

[0027] (2) The present invention constructs a test device for obtaining the arc magnetohydrodynamic motion law of a multi-gap arrester, providing support for the performance evaluation of the multi-gap arrester. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of an arc extinguishing characteristic evaluation device for a multi-gap arrester in the present invention;

[0029] Figure 2 It is a schematic diagram of the multi-gap structure in the present invention;

[0030] Figure 3 It is a flowchart of a method for evaluating the arc extinguishing characteristics of a multi-gap arrester in the present invention; SPECIFIC EMBODIMENTS

[0031] The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. On the contrary, they are merely examples of methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0032] The terms used in the present disclosure are for the purpose of describing specific embodiments only and are not intended to limit the present disclosure. The singular forms "a", "said", and "the" used in the present disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0033] The following further illustrates the specific embodiments of the present invention with reference to specific embodiments:

[0034] The multi-gap arrester tested in the present invention belongs to the arrester for 110 kV power transmission and distribution lines and is installed between the phase wire and the ground. After the lightning current hits the high-voltage transmission line conductor, the lightning current is discharged to the ground through the multi-gap arrester, establishing an arc magnetohydrodynamic discharge channel. The arc magnetohydrodynamic jets out through the arc extinguishing holes of the multi-gap arrester, weakening the lightning energy.

[0035] An arc extinguishing characteristic evaluation device for a multi-gap arrester, as Figure 1 shown, includes a test platform, an impulse current generator, a voltage measurement probe, a current measurement coil, an image capture unit, and a control and measurement system; the test platform is used to connect the multi-gap arrester, and the impulse current generator, the current measurement coil, the voltage measurement probe, and the image capture unit are all connected to the test platform and the control and measurement system.

[0036] The basic composition structure of the multi-gap arrester is a multi-gap structure, as Figure 2 shown, and the multi-gap structure includes but is not limited to the following parameters:

[0037] L1 represents the depth of the arc extinguishing hole;

[0038] represents the diameter of the arc extinguishing hole;

[0039] L2 represents the gap distance;

[0040] The shaded part is the insulating material;

[0041] The middle circular part is the spherical metal electrode;

[0042] Based on the magnetohydrodynamics (MHD) theory, during the process of the multi-gap arrester spraying arc magnetofluid, the evaluation characterization indexes of the multi-gap arrester performance include, but are not limited to, the following characterization indexes: arc conductivity, maximum arc spraying height, maximum arc spraying speed, and arc temperature.

[0043] The image is taken by a high-speed camera;

[0044] The distance between the high-speed camera and the test platform is 5 m;

[0045] The control and measurement system includes an oscilloscope and a computer. The oscilloscope is connected to the current measurement coil and the voltage measurement probe;

[0046] A method for evaluating the arc extinguishing characteristics of a multi-gap arrester uses a device for evaluating the arc extinguishing characteristics of a multi-gap arrester as described above, as Figure 3 shown, and includes the following steps:

[0047] S1. Set up a device for evaluating the arc extinguishing characteristics of a multi-gap arrester, connect the multi-gap arrester to be tested to the test platform, and set the charging voltage and impulse current;

[0048] S2. The impulse current generator generates impulse current waves with different waveforms and amplitudes. When the impulse current flows through the multi-gap arrester, a spray-like arc magnetofluid is generated;

[0049] S3. The high-speed camera takes pictures of the high-speed motion state of the arc magnetofluid and transmits it to the control and measurement system, calculates the spraying speed of the arc magnetofluid, performs image calibration and post-processing on the taken arc spraying photos, and calculates the temperature change characteristics of the arc based on the double-wavelength two-color temperature measurement method. The shooting part needs to be processed in a blackbody environment in advance;

[0050] The expression for the spraying speed is:

[0051] V = L × 10 -3 / t;

[0052] where V is the spraying speed, and the unit is m / s;

[0053] L is the upward ejection distance of the arc, with the unit of mm;

[0054] t is the ejection time, with the unit of s.

[0055] S4. The voltage probe obtains the residual voltage of the multi-gap arrester, and the current measurement coil obtains the impulse current and transmits it to the oscilloscope. The oscilloscope collects and records it, and then transmits it to the control and measurement system.

[0056] The acquisition speed of the high-speed camera is more than 10,000 frames per second. Otherwise, the high-speed motion state of the arc magnetohydrodynamics cannot be captured. According to the frame rate of the high-speed camera and the motion forms of the arc magnetohydrodynamics at different times, the ejection speed of the arc magnetohydrodynamics is calculated.

[0057] Compare the obtained ejection speed, residual voltage, and temperature of the arc magnetohydrodynamics with relevant standards and literature to evaluate the arc extinguishing characteristics of the multi-gap arrester.

[0058] The impulse current generator can generate impulse current waves with waveforms of 8 / 20 μs, 4 / 10 μs, 10 / 350 μs, 30 / 80 μs and amplitudes of 0 - 200 kA.

[0059] Embodiment 1

[0060] Apply an 8 / 20 μs impulse current wave of 17.9 kA to the multi-gap arrester to obtain its arc extinguishing characteristics;

[0061] An arc extinguishing characteristic evaluation device for a multi-gap arrester includes a test platform, an impulse current generator, a voltage measurement probe, a current measurement coil, an image capturing unit, and a control and measurement system; the test platform is used to connect the multi-gap arrester, and the impulse current generator, the current measurement coil, and the voltage measurement probe are all connected to the test platform and the control and measurement system.

[0062] The basic composition structure of the multi-gap arrester is a multi-gap structure. As Figure 2 shown, the multi-gap structure includes but is not limited to the following parameters:

[0063] L1 represents the depth of the arc extinguishing hole, and its value is 12 mm;

[0064] represents the diameter of the arc extinguishing hole, and its value is 3 mm;

[0065] L2 represents the gap distance, and its value is 0.8 mm;

[0066] The shaded part is the insulating material;

[0067] The middle circular part is the spherical metal electrode;

[0068] Based on the magnetohydrodynamics (MHD) theory, during the process of a multi-gap arrester jetting arc magnetofluid, the evaluation characterization indexes of the multi-gap arrester performance include, but are not limited to, the following characterization indexes: arc conductivity, maximum arc jet height, maximum arc jet speed, and arc temperature.

[0069] The image is taken by a high-speed camera;

[0070] The distance between the high-speed camera and the test platform is 5 m;

[0071] The control and measurement system includes an oscilloscope and a computer. The oscilloscope is connected to the current measurement coil and the voltage measurement probe.

[0072] A method for evaluating the arc extinction characteristics of a multi-gap arrester, using a device for evaluating the arc extinction characteristics of a multi-gap arrester as described above, includes the following steps:

[0073] S1. Set up the device for evaluating the arc extinction characteristics of the multi-gap arrester, connect the multi-gap arrester to be tested to the test platform, set the charging voltage to 26 kV, and the impulse current waveform to 8 / 20 μs;

[0074] S2. The impulse current generator generates impulse current waves with different waveforms and amplitudes. When the impulse current flows through the multi-gap arrester, jet-shaped arc magnetofluid is generated;

[0075] S3. The high-speed camera takes pictures of the high-speed motion state of the arc magnetofluid and transmits it to the control and measurement system, and calculates the jet speed of the arc magnetofluid;

[0076] The expression for the jet speed is:

[0077] V = L × 10 -3 / t;

[0078] where V is the jet speed, with the unit of m / s;

[0079] L is the upward ejection distance of the arc, with the unit of mm;

[0080] t is the ejection time, with the unit of s;

[0081] When t = 4.64 μs, the upward ejection distance of the arc increases to 9 mm, and the jet speed V = (9 - 0) × 10 -3 / (4.64 - 0) × 10 -6 = 1939 m / s. Arcs appear in all multi-gap holes, with stronger brightness at the head and end, and relatively uniform brightness distribution in the middle 8 holes;

[0082] When t = 9.29 μs, the upward ejection distance of the arc increases to 14 mm, and the jet speed V = (14 - 9) × 10 -3 / (9.29 - 4.64)×10 -6 = 718 m / s.

[0083] Image calibration and post - processing were performed on the arc jet photos taken by the high - speed camera at t = 9.29 μs. Based on the dual - wavelength two - color temperature measurement method, the temperature change characteristics of the arc were calculated. The arc temperature reached the highest, and the temperature at the center of the arc column was about 12,000 K;

[0084] S4. The voltage probe obtained the residual voltage of the multi - gap arrester as 1.96 kV, and the current measurement coil obtained the impulse current as 17.9 kA, and transmitted them to the oscilloscope. The oscilloscope collected and recorded them, and then transmitted them to the control and measurement system.

[0085] The acquisition speed of the high - speed camera is more than 10,000 frames per second. Otherwise, the high - speed motion state of the arc magnetohydrodynamics cannot be captured. According to the frame rate of the high - speed camera and the motion forms of the arc magnetohydrodynamics at different times, the jet speed of the arc magnetohydrodynamics was calculated.

[0086] The obtained jet speed, residual voltage, temperature of the arc magnetohydrodynamics were compared with relevant standards and literature to evaluate the arc extinguishing characteristics of the multi - gap arrester.

[0087] The impulse current generator can generate impulse current waves with waveforms of 8 / 20 μs, 4 / 10 μs, 10 / 350 μs, 30 / 80 μs and amplitudes of 0 - 200 kA.

[0088] Example 2

[0089] Apply an 8 / 20 μs impulse current wave of 60 kA to the multi - gap arrester to obtain its arc extinguishing characteristics;

[0090] An arc extinguishing characteristic evaluation device for a multi - gap arrester includes a test platform, an impulse current generator, a voltage measurement probe, a current measurement coil, an image shooting unit and a control and measurement system; the test platform is used to connect the multi - gap arrester, and the impulse current generator, the current measurement coil and the voltage measurement probe are all connected to the test platform and the control and measurement system.

[0091] The basic composition structure of the multi - gap arrester is a multi - gap structure. As Figure 2 shown, the multi - gap structure includes but is not limited to the following parameters:

[0092] L1 represents the depth of the arc extinguishing hole, and its value is 18 mm;

[0093] represents the diameter of the arc extinguishing hole, and its value is 5 mm;

[0094] L2 represents the gap distance, and its value is 1 mm;

[0095] The shaded part is made of insulating material;

[0096] The middle circular part is a spherical metal electrode;

[0097] Based on the magnetohydrodynamics (MHD) theory, during the process of the multi-gap arrester spraying arc magnetofluid, the evaluation characterization indexes of the multi-gap arrester performance include, but are not limited to, the following characterization indexes: arc conductivity, maximum arc spraying height, maximum arc spraying speed, and arc temperature.

[0098] The image is captured by a high-speed camera;

[0099] The distance between the high-speed camera and the test platform is 5 m;

[0100] The control and measurement system includes an oscilloscope and a computer. The oscilloscope is connected to the current measurement coil and the voltage measurement probe.

[0101] A method for evaluating the arc extinction characteristics of a multi-gap arrester, using a device for evaluating the arc extinction characteristics of a multi-gap arrester as described above, includes the following steps:

[0102] S1. Set up the device for evaluating the arc extinction characteristics of the multi-gap arrester, connect the multi-gap arrester to be tested to the test platform, set the charging voltage to 23437 V, and the impulse current waveform to 8 / 20 μs;

[0103] S2. The impulse current generator generates impulse current waves with different waveforms and amplitudes. When the impulse current flows through the multi-gap arrester, a spray-like arc magnetofluid is generated;

[0104] S3. The high-speed camera captures the high-speed motion state of the arc magnetofluid and transmits it to the control and measurement system, and the spraying speed of the arc magnetofluid is calculated;

[0105] The expression for the spraying speed is:

[0106] V = L × 10 -3 / t;

[0107] where V is the spraying speed, with the unit of m / s;

[0108] L is the upward spraying distance of the arc, with the unit of mm;

[0109] t is the spraying time, with the unit of s;

[0110] When t = 4.64 μs, the upward spraying distance of the arc increases to 4 mm, and the spraying speed V = (4 - 0) × 10 -3 / (4.64 - 0) × 10 -6 = 862 m / s. Arcs appear in all multi-gap holes, with stronger brightness at the head and tail, and relatively uniform brightness distribution in the middle 8 holes;

[0111] At t = 6.96 μs, the upward ejection distance of the arc increases to 9 mm, and the ejection speed V = (9 - 4)×10 -3 / (6.96 - 4.64)×10 -6 = 2155 m / s.

[0112] Image calibration and post - processing are performed on the arc ejection photos taken by the high - speed camera at t = 9.29 μs. Based on the double - wavelength two - color temperature measurement method, the temperature change characteristics of the arc are calculated. The arc temperature reaches the highest, and the center temperature of the arc column is about 12000 K;

[0113] S4. The voltage probe obtains the residual voltage of the multi - gap arrester as 1.56 kV, and the current measurement coil obtains the impulse current as 60 kA, and transmits them to the oscilloscope. The oscilloscope collects and records them, and then transmits them to the control and measurement system.

[0114] The acquisition speed of the high - speed camera is above 10000 frames per second. Otherwise, the high - speed motion state of the arc magnetohydrodynamics cannot be captured. According to the frame rate of the high - speed camera and the motion forms of the arc magnetohydrodynamics at different times, the ejection speed of the arc magnetohydrodynamics is calculated.

[0115] The obtained ejection speed, residual voltage, and temperature of the arc magnetohydrodynamics are compared with relevant standards and literature to evaluate the arc extinguishing characteristics of the multi - gap arrester.

[0116] The impulse current generator can generate impulse current waves with waveforms of 8 / 20 μs, 4 / 10 μs, 10 / 350 μs, 30 / 80 μs and amplitudes of 0 - 200 kA.

[0117] Embodiment 3

[0118] Apply an 8 / 20 μs impulse current wave of 42 kA to the multi - gap arrester to obtain its arc extinguishing characteristics;

[0119] An arc extinguishing characteristic evaluation device for a multi - gap arrester, comprising a test platform, an impulse current generator, a voltage measurement probe, a current measurement coil, an image shooting unit, and a control and measurement system; the test platform is used to connect the multi - gap arrester, and the impulse current generator, the current measurement coil, and the voltage measurement probe are all connected to the test platform and the control and measurement system.

[0120] The basic composition structure of the multi - gap arrester is a multi - gap structure. As Figure 2 shown, the multi - gap structure includes but is not limited to the following parameters:

[0121] L1 represents the depth of the arc extinguishing hole, and its value is 12 mm;

[0122] represents the diameter of the arc extinguishing hole, and its value is 3 mm;

[0123] L2 represents the clearance distance, and its value is 0.8 mm;

[0124] The shaded part is the insulating material;

[0125] The middle circular part is the spherical metal electrode;

[0126] Based on the magnetohydrodynamics (MHD) theory, during the process of the multi-gap arrester spraying arc magnetofluid, the evaluation characterization indexes of the multi-gap arrester performance include, but are not limited to, the following characterization indexes: arc conductivity, maximum arc spraying height, maximum arc spraying speed, and arc temperature.

[0127] The image is taken by a high-speed camera;

[0128] The distance between the high-speed camera and the test platform is 5 m;

[0129] The control and measurement system includes an oscilloscope and a computer. The oscilloscope is connected to the current measurement coil and the voltage measurement probe.

[0130] A method for evaluating the arc extinguishing characteristics of a multi-gap arrester, using a device for evaluating the arc extinguishing characteristics of a multi-gap arrester as described above, includes the following steps:

[0131] S1. Set up the device for evaluating the arc extinguishing characteristics of the multi-gap arrester, connect the multi-gap arrester to be tested to the test platform, set the charging voltage to 34 kV, and the impulse current waveform to 8 / 20 μs;

[0132] S2. The impulse current generator generates impulse current waves with different waveforms and amplitudes. When the impulse current flows through the multi-gap arrester, a spray-shaped arc magnetofluid is generated;

[0133] S3. The high-speed camera takes pictures of the high-speed motion state of the arc magnetofluid and transmits it to the control and measurement system, and calculates the spraying speed of the arc magnetofluid;

[0134] The expression for the spraying speed is:

[0135] V = L × 10 -3 / t;

[0136] Where, V is the spraying speed, and the unit is m / s;

[0137] L is the upward spraying distance of the arc, and the unit is mm;

[0138] t is the spraying time, and the unit is s;

[0139] When t = 11.11 μs, the upward spraying distance of the arc increases to 17 mm, and the spraying speed V = (17 - 0) × 10 -3 / (11.11 - 0) × 10-6 = 1530 m / s. Electric arc glow appears in all multi-gap holes, and the electric arc jet from the multi-gap holes is in a cluster shape;

[0140] At t = 16.66 μs, the upward ejection distance of the electric arc increases to 24 mm, and the ejection speed V = (24 - 17) × 10 -3 / (16.66 - 11.11) × 10 -6 = 1261 m / s.

[0141] Image calibration and post-processing are performed on the electric arc jet photo taken by the high-speed camera at t = 16.66 μs. Based on the dual-wavelength two-color temperature measurement method, the temperature change characteristics of the electric arc are calculated. The electric arc temperature reaches the highest, and the temperature at the center of the arc column is about 12000 K;

[0142] S4. The voltage probe obtains the residual voltage of the multi-gap lightning arrester as 2.62 kV, and the current measurement coil obtains the impulse current as 42 kA, and transmits it to the oscilloscope. The oscilloscope collects and records it, and then transmits it to the control and measurement system.

[0143] The acquisition speed of the high-speed camera is above 10000 frames per second. Otherwise, the high-speed motion state of the arc magnetohydrodynamics cannot be captured. According to the frame rate of the high-speed camera and the motion morphology of the arc magnetohydrodynamics at different times, the ejection speed of the arc magnetohydrodynamics is calculated.

[0144] The obtained ejection speed, residual voltage, and temperature of the arc magnetohydrodynamics are compared with relevant standards and literature to evaluate the arc extinguishing characteristics of the multi-gap lightning arrester.

[0145] The impulse current generator can generate impulse current waves with waveforms of 8 / 20 μs, 4 / 10 μs, 10 / 350 μs, 30 / 80 μs, and amplitudes of 0 - 200 kA.

[0146] Example 4

[0147] Apply an 8 / 20 μs impulse current wave of 24.7 kA to the multi-gap lightning arrester to obtain its arc extinguishing characteristics;

[0148] An arc extinguishing characteristic evaluation device for a multi-gap lightning arrester, comprising a test platform, an impulse current generator, a voltage measurement probe, a current measurement coil, an image capturing unit, and a control and measurement system; the test platform is used to connect the multi-gap lightning arrester, and the impulse current generator, the current measurement coil, and the voltage measurement probe are all connected to the test platform and the control and measurement system.

[0149] The basic composition structure of the multi-gap lightning arrester is a multi-gap structure. As Figure 2 shown, the multi-gap structure includes but is not limited to the following parameters:

[0150] L1 represents the arc extinguishing hole depth, and its value is 12 mm;

[0151] represents the arc extinguishing hole diameter, and its value is 3 mm;

[0152] L2 represents the gap distance, and its value is 0.8 mm;

[0153] The shaded part is the insulating material;

[0154] The middle circular part is the spherical metal electrode;

[0155] Based on the magnetohydrodynamics (MHD) theory, during the process of the multi-gap arrester spraying arc magnetofluid, the evaluation characterization indexes of the multi-gap arrester performance include, but are not limited to, the following characterization indexes: arc conductivity, maximum arc spraying height, maximum arc spraying speed, and arc temperature.

[0156] The image is taken by a high-speed camera;

[0157] The distance between the high-speed camera and the test platform is 5 m;

[0158] The control and measurement system includes an oscilloscope and a computer, and the oscilloscope is connected to the current measurement coil and the voltage measurement probe.

[0159] A method for evaluating the arc extinguishing characteristics of a multi-gap arrester, using a device for evaluating the arc extinguishing characteristics of a multi-gap arrester as described above, includes the following steps:

[0160] S1. Set up a device for evaluating the arc extinguishing characteristics of a multi-gap arrester, connect the multi-gap arrester to be tested to the test platform, set the charging voltage to 40 kV, and the impulse current waveform to 8 / 20 μs;

[0161] S2. The impulse current generator generates impulse current waves with different waveforms and amplitudes. When the impulse current flows through the multi-gap arrester, a jet-like arc magnetofluid is generated;

[0162] S3. The high-speed camera takes pictures of the high-speed motion state of the arc magnetofluid and transmits it to the control and measurement system, and calculates the spraying speed of the arc magnetofluid;

[0163] The expression for the spraying speed is:

[0164] V = L × 10 -3 / t;

[0165] Where, V is the spraying speed, and the unit is m / s;

[0166] L is the upward spraying distance of the arc, and the unit is mm;

[0167] t is the spraying time, and the unit is s;

[0168] At t = 6.57 μs, the upward ejection distance of the arc increases to 11 mm, and the ejection speed V = (11 - 0) × 10 -3 / (6.57 - 0) × 10 -6 = 1674 m / s. Arclight appears in all multi-gap holes, with stronger light at the head and end, and a relatively uniform brightness distribution in the middle 8 holes;

[0169] At t = 10.95 μs, the upward ejection distance of the arc increases to 27 mm, and the ejection speed V = (27 - 11) × 10 -3 / (10.95 - 6.57) × 10 -6 = 3653 m / s.

[0170] Image calibration and post-processing are performed on the arc ejection photo taken by the high-speed camera at t = 10.95 μs. Based on the double-wavelength two-color temperature measurement method, the temperature change characteristics of the arc are calculated, and the arc temperature reaches the highest, with the center temperature of the arc column being approximately 12000 K;

[0171] S4. The voltage probe obtains the residual voltage of the multi-gap arrester as 2.08 kV, and the current measurement coil obtains the impulse current as 24.7 kA, and transmits it to the oscilloscope. The oscilloscope performs acquisition and recording, and then transmits it to the control and measurement system.

[0172] The acquisition speed of the high-speed camera is above 10000 frames per second. Otherwise, the high-speed motion state of the arc magnetohydrodynamics cannot be captured. According to the frame rate of the high-speed camera and the motion forms of the arc magnetohydrodynamics at different times, the ejection speed of the arc magnetohydrodynamics is calculated.

[0173] Compare the obtained ejection speed, residual voltage, and temperature of the arc magnetohydrodynamics with relevant standards and literature to evaluate the arc extinction characteristics of the multi-gap arrester.

[0174] The impulse current generator can generate impulse current waves with waveforms of 8 / 20 μs, 4 / 10 μs, 10 / 350 μs, 30 / 80 μs, and amplitudes of 0 - 200 kA.

[0175] Example 5

[0176] Apply an 8 / 20 μs impulse current wave of 13.1 kA to the multi-gap arrester to obtain its arc extinction characteristics;

[0177] An arc extinction characteristic evaluation device for a multi-gap arrester includes a test platform, an impulse current generator, a voltage measurement probe, a current measurement coil, an image shooting unit, and a control and measurement system; the test platform is used to connect the multi-gap arrester, and the impulse current generator, current measurement coil, and voltage measurement probe are all connected to the test platform and the control and measurement system.

[0178] The basic composition structure of the multi-gap arrester is a multi-gap structure. As Figure 2 shown, the multi-gap structure includes but is not limited to the following parameters:

[0179] L1 represents the depth of the arc quenching hole, and its value is 12 mm;

[0180] represents the diameter of the arc quenching hole, and its value is 3 mm;

[0181] L2 represents the gap distance, and its value is 0.8 mm;

[0182] The shaded part is the insulating material;

[0183] The middle circular part is the spherical metal electrode;

[0184] Based on the magnetohydrodynamics (MHD) theory, during the process of the multi-gap arrester spraying arc magnetofluid, the evaluation characterization indexes of the performance of the multi-gap arrester include but are not limited to the following characterization indexes: arc conductivity, maximum arc spraying height, maximum arc spraying speed, and arc temperature.

[0185] The image is taken by a high-speed camera;

[0186] The distance between the high-speed camera and the test platform is 5 m;

[0187] The control and measurement system includes an oscilloscope and a computer. The oscilloscope is connected to the current measurement coil and the voltage measurement probe.

[0188] A method for evaluating the arc quenching characteristics of a multi-gap arrester, using a device for evaluating the arc quenching characteristics of a multi-gap arrester as described above, includes the following steps:

[0189] S1. Set up a device for evaluating the arc quenching characteristics of a multi-gap arrester, connect the multi-gap arrester to be tested to the test platform, set the charging voltage to 22 kV, and the impulse current waveform to 8 / 20 μs;

[0190] S2. The impulse current generator generates impulse current waves with different waveforms and amplitudes. When the impulse current flows through the multi-gap arrester, a spray-shaped arc magnetofluid is generated;

[0191] S3. The high-speed camera takes pictures of the high-speed motion state of the arc magnetofluid and transmits it to the control and measurement system, and calculates the spraying speed of the arc magnetofluid;

[0192] The expression for the spraying speed is:

[0193] V = L × 10 -3 / t;

[0194] where V is the spraying speed, and the unit is m / s;

[0195] L is the upward ejection distance of the arc, with the unit of mm;

[0196] t is the ejection time, with the unit of s;

[0197] At t = 5.33 μs, the upward ejection distance of the arc increases to 2 mm, and the ejection speed V = (2 - 0) × 10 -3 / (5.33 - 0) × 10 -6 = 375 m / s. Electric arc lights appear in all multi-gap holes. The light is stronger at the head and the end, and the brightness distribution of the 8 holes in the middle is relatively uniform;

[0198] At t = 14.67 μs, the upward ejection distance of the arc increases to 12 mm, and the ejection speed V = (12 - 2) × 10 -3 / (14.67 - 5.33) × 10 -6 = 1071 m / s.

[0199] Image calibration and post-processing are performed on the arc ejection photo taken by the high-speed camera at t = 14.67 μs. Based on the double-wavelength two-color temperature measurement method, the temperature change characteristics of the arc are calculated. The arc temperature reaches the highest, and the temperature at the center of the arc column is about 12000 K;

[0200] S4. The voltage probe obtains the residual voltage of the multi-gap arrester as 2.28 kV, and the current measurement coil obtains the impulse current as 13.1 kA and transmits it to the oscilloscope. The oscilloscope collects and records it, and then transmits it to the control and measurement system.

[0201] The acquisition speed of the high-speed camera is more than 10000 frames per second. Otherwise, the high-speed motion state of the arc magnetohydrodynamics cannot be captured. According to the frame rate of the high-speed camera and the motion forms of the arc magnetohydrodynamics at different times, the ejection speed of the arc magnetohydrodynamics is calculated.

[0202] The obtained ejection speed, residual voltage, and temperature of the arc magnetohydrodynamics are compared with relevant standards and literature to evaluate the arc extinguishing characteristics of the multi-gap arrester.

[0203] The impulse current generator can generate impulse current waves with waveforms of 8 / 20 μs, 4 / 10 μs, 10 / 350 μs, 30 / 80 μs, and amplitudes of 0 - 200 kA.

[0204] Example 6

[0205] Apply an 8 / 20 μs impulse current wave of 16.8 kA to the multi-gap arrester to obtain its arc extinguishing characteristics;

[0206] A device for evaluating the arc quenching characteristics of a multi-gap arrester, comprising a test platform, an impulse current generator, a voltage measurement probe, a current measurement coil, an image capturing unit, and a control and measurement system; the test platform is used to connect the multi-gap arrester, and the impulse current generator, the current measurement coil, and the voltage measurement probe are all connected to the test platform and the control and measurement system.

[0207] The basic composition structure of the multi-gap arrester is a multi-gap structure. As Figure 2 shown, the multi-gap structure includes but is not limited to the following parameters:

[0208] L1 represents the depth of the arc quenching hole, and its value is 12 mm;

[0209] represents the diameter of the arc quenching hole, and its value is 3 mm;

[0210] L2 represents the gap distance, and its value is 0.8 mm;

[0211] The shaded part is the insulating material;

[0212] The middle circular part is a spherical metal electrode;

[0213] Based on the magnetohydrodynamics (MHD) theory, during the process of the multi-gap arrester spraying arc magnetofluid, the evaluation characterization indexes of the performance of the multi-gap arrester include but are not limited to the following characterization indexes: arc conductivity, maximum spraying height of the arc, maximum spraying speed of the arc, and arc temperature.

[0214] The image capturing unit is a high-speed camera;

[0215] The distance between the high-speed camera and the test platform is 5 m;

[0216] The control and measurement system includes an oscilloscope and a computer, and the oscilloscope is connected to the current measurement coil and the voltage measurement probe.

[0217] A method for evaluating the arc quenching characteristics of a multi-gap arrester, using the device for evaluating the arc quenching characteristics of a multi-gap arrester as described above, includes the following steps:

[0218] S1. Set up the device for evaluating the arc quenching characteristics of the multi-gap arrester, connect the multi-gap arrester to be tested to the test platform, set the charging voltage to 28 kV, and the impulse current waveform to 8 / 20 μs;

[0219] S2. The impulse current generator generates impulse current waves with different waveforms and amplitudes. When the impulse current flows through the multi-gap arrester, a spray-like arc magnetofluid is generated;

[0220] S3. The high-speed camera captures the high-speed motion state of the arc magnetofluid and transmits it to the control and measurement system, and calculates the spraying speed of the arc magnetofluid;

[0221] The jet velocity expression is as follows:

[0222] V = L × 10 -3 / t;

[0223] Wherein, V is the jet velocity, with the unit of m / s;

[0224] L is the upward jet distance of the arc, with the unit of mm;

[0225] t is the jet time, with the unit of s;

[0226] When t = 5.33 μs, the upward jet distance of the arc increases to 3 mm, and the jet velocity V = (3 - 0) × 10 -3 / (5.33 - 0) × 10 -6 = 562 m / s, and arc lights appear in all multi-gap holes. The light is stronger at the head and the end, and the brightness distribution of the 8 holes in the middle is relatively uniform;

[0227] When t = 14.67 μs, the upward jet distance of the arc increases to 13 mm, and the jet velocity V = (13 - *3) × 10 -3 / (14.67 - 5.33) × 10 -6 = 1071 m / s.

[0228] Image calibration and post-processing are performed on the arc jet photo taken by the high-speed camera at t = 14.67 μs. Based on the dual-wavelength two-color temperature measurement method, the temperature change characteristics of the arc are calculated, and the arc temperature reaches the highest, with the center temperature of the arc column being approximately 12000 K;

[0229] S4. The voltage probe obtains the residual voltage of the multi-gap arrester as 1.96 kV, and the current measurement coil obtains the impulse current as 16.8 kA and transmits it to the oscilloscope. The oscilloscope performs acquisition and recording, and then transmits it to the control and measurement system.

[0230] The acquisition speed of the high-speed camera is above 10000 frames per second. Otherwise, the high-speed motion state of the arc magnetohydrodynamics cannot be captured. According to the frame rate of the high-speed camera and the motion forms of the arc magnetohydrodynamics at different moments, the jet velocity of the arc magnetohydrodynamics is calculated.

[0231] The obtained jet velocity, residual voltage, and temperature of the arc magnetohydrodynamics are compared with relevant standards and literature to evaluate the arc extinguishing characteristics of the multi-gap arrester.

[0232] The impulse current generator can generate impulse current waves with waveforms of 8 / 20 μs, 4 / 10 μs, 10 / 350 μs, 30 / 80 μs, and amplitudes of 0 - 200 kA.

[0233] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and the devices and structures not described in detail should be understood to be implemented in a common manner in the art; any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above, or modify it into an equivalent embodiment with equivalent changes, which does not affect the essence of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. An evaluation device for the arc extinguishing characteristics of a multi-gap lightning arrester, characterized in that, It includes a test platform, an impulse current generator, a voltage measurement probe, a current measurement coil, an image capture unit, and a control and measurement system; the test platform is used to connect a multi-gap lightning arrester, and the impulse current generator, the current measurement coil, the voltage measurement probe, and the image capture unit are all connected to the test platform and the control and measurement system.

2. The arc extinguishing characteristic evaluation device for a multi-gap lightning arrester according to claim 1, characterized in that The image capture unit is a high-speed camera.

3. The arc extinction characteristic evaluation device of a multi-gap lightning arrester according to claim 2, characterized in that, The distance between the high-speed camera and the test platform is 5 m.

4. The arc quenching characteristic evaluation device for a multi-gap lightning arrester according to claim 1, characterized in that, The control and measurement system includes an oscilloscope and a computer, and the oscilloscope is connected to the current measurement coil and the voltage measurement probe.

5. The arc extinction characteristic evaluation device of a multi-gap lightning arrester according to claim 1, characterized in that, The multi-gap lightning arrester belongs to the lightning arrester for 110 kV power transmission and distribution lines and is installed between the phase line and the ground.

6. A method for evaluating the arc quenching characteristics of a multi-gap lightning arrester, characterized in that, Using the device for evaluating the arc quenching characteristics of a multi-gap lightning arrester according to any one of claims 1-5, it includes the following steps: S1. Build the device for evaluating the arc quenching characteristics of a multi-gap lightning arrester, connect the multi-gap lightning arrester to be tested to the test platform, and set the charging voltage and the impulse current. S2. The impulse current generator generates impulse current waves with different waveforms and different amplitudes. When the impulse current flows through the multi-gap lightning arrester, a jet-shaped arc magnetohydrodynamic is generated. S3. The high-speed camera captures the high-speed motion state of the arc magnetohydrodynamic and transmits it to the control and measurement system, calculates the jet speed of the arc magnetohydrodynamic, performs image calibration and post-processing on the captured arc jet photos, and calculates the temperature change characteristics of the arc based on the dual-wavelength two-color temperature measurement method. S4. The voltage probe obtains the residual voltage of the multi-gap lightning arrester, the current measurement coil obtains the impulse current, and transmits them to the oscilloscope. The oscilloscope collects and records them and then transmits them to the control and measurement system.

7. A method for evaluating the arc quenching characteristics of a multi-gap lightning arrester according to claim 6, characterized in that, The acquisition speed of the high-speed camera is more than 10,000 frames per second.

8. A method for evaluating the arc quenching characteristics of a multi-gap lightning arrester according to claim 6, characterized in that, Compare the obtained jet speed, residual voltage, and temperature of the arc magnetohydrodynamic with relevant standards and literature to evaluate the arc quenching characteristics of the multi-gap lightning arrester.

9. A method for evaluating the arc quenching characteristics of a multi-gap lightning arrester according to claim 6, characterized in that, The impulse current generator can generate impulse current waves with waveforms of 8 / 20 μs, 4 / 10 μs, 10 / 350 μs, 30 / 80 μs and amplitudes of 0-200 kA.

10. A method for evaluating the arc extinguishing characteristics of a multi-gap lightning arrester according to claim 6, characterized in that, The expression of the jet speed is: V = L × 10 -3 / t; Where, V is the jet speed, the unit is m / s, L is the upward ejection distance of the arc, the unit is mm, and t is the ejection time, the unit is s.

Images