Method and system for determining altitude correction coefficient of corona onset initial voltage
By conducting insulation gap simulation tests in railway traction power supply systems in high-altitude and complex climate areas, the altitude correction coefficient is determined, which solves the problem of difficulty in determining the altitude correction coefficient in insulation characteristic tests and achieves the stability and reliability of electrical insulation performance.
Patent Information
- Application Number
- CN202411293917.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-14
- Publication Date
- 2025-01-24
AI Technical Summary
In railway traction power supply systems in high-altitude complex climate areas, it is difficult to effectively determine the altitude correction coefficient when the insulation characteristic test is performed, resulting in unstable electrical insulation performance.
By performing an insulation gap simulation test under different test environment conditions, the test results data of the start voltage of fainting, and calculating the absolute humidity based on the relative humidity and environmental temperature, the altitude correction factor is determined by the fitting method.
It achieves accurate correction of corona onset voltage in complex environments, improves the stability and reliability of insulation performance, and is suitable for railway traction power supply systems with high altitudes and high bridge-to-tunnel ratios.
Smart Images
Figure CN119355455A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of insulation characteristic testing, and in particular to a method and system for determining an altitude correction coefficient of a corona inception voltage. Background Art
[0002] China's railways are developing rapidly. In 2022, the mileage of China's railways in the east has exceeded 140,000 kilometers, of which the mileage of high-speed railways ranks first in the world. China's railways run from north to south and from east to west, and the climate regions they pass through are complex. At the same time, railway lines in high-altitude and complex climate regions such as the Qinghai-Tibet Railway and the Sichuan-Tibet Railway are developing rapidly, especially the Sichuan-Tibet Railway, which has a total length of about 1,700km. More than 80% will be built in the form of tunnels and bridges. The total length of tunnels along the entire line is 1,400km, and the cumulative climbing height is more than 16,000 meters. The bridge-tunnel ratio is high and the pollution dispersion capacity is poor; the altitude rises from 1,000m to 4,500km. The Sichuan-Tibet Railway has a high altitude, a high bridge-tunnel ratio, a large temperature difference and other comprehensive extreme harsh environments that bring challenges to the insulation of the traction power supply. It is urgent to determine the altitude correction factor through insulation gap simulation tests. Summary of the invention
[0003] The present invention provides a method and system for determining an altitude correction coefficient of a corona onset voltage, which can obtain an altitude correction coefficient of the corona onset voltage corresponding to a sample under the same relative humidity and different absolute humidity, so as to be suitable for correcting the corona onset voltage in a complex environment.
[0004] In a first aspect, the present disclosure provides a method for determining an altitude correction coefficient of a corona onset voltage, comprising:
[0005] Acquire test result data of insulation gap simulation tests of the sample to be tested under multiple groups of different test environment conditions, wherein the test result data includes the test environment conditions and the corona inception voltage of the sample to be tested under the test environment conditions, wherein the test environment conditions include ambient temperature, relative humidity and altitude;
[0006] According to the relative humidity and ambient temperature in each group of test result data, the absolute humidity corresponding to the group of test result data is obtained;
[0007] The test result data with the same relative humidity were fitted according to the preset corona onset voltage correction calculation formula to obtain the altitude correction coefficient of the corona onset voltage corresponding to the tested sample at the same relative humidity and different absolute humidity.
[0008] In some embodiments, the steps of the insulation gap simulation test include:
[0009] Pre-treat the samples to be tested;
[0010] Placing the pretreated sample under set test environment conditions, wherein the test environment conditions include ambient temperature, relative humidity and altitude;
[0011] A voltage is applied to the sample to be tested in the set test environment conditions, and the voltage applied to the sample to be tested is gradually increased by a step-by-step voltage-boosting method until partial discharge is detected on the sample to be tested. The voltage applied to the sample to be tested at this time is used as the corona initiation voltage of the sample to be tested in the current test environment conditions.
[0012] In some embodiments, the sample to be tested is pretreated, including:
[0013] The surface of the sample to be tested is wiped with anhydrous ethanol, and the wiped sample to be tested is dried.
[0014] In some embodiments, the pre-treated sample to be tested is subjected to an insulation gap simulation test through a preset insulation gap simulation test device to obtain the test result data, wherein the insulation gap simulation test device includes a test power supply, an oscilloscope, a pulse current measurement branch, an ultrasonic measurement branch, a current sensor, a metal shell, and a high-voltage electrode and a grounding electrode arranged in the metal shell;
[0015] The high voltage end of the test power supply is connected to the high voltage electrode, and the low voltage end of the test power supply is connected to the ground electrode;
[0016] The first end of the current sensor is connected to the ground electrode, the second end of the current sensor is connected to the input end of the pulse current measurement branch, and the output end of the pulse current measurement branch is connected to the first signal input end of the oscilloscope;
[0017] The input end of the ultrasonic measurement branch is connected to the inner wall of the metal shell, and the output end of the ultrasonic measurement branch is connected to the second signal input end of the oscilloscope.
[0018] In some embodiments, the pulse current measurement branch includes a first amplifier and a filter, the input end of the first amplifier serves as the input end of the pulse current measurement branch, the output end of the first amplifier is connected to the input end of the filter, and the output end of the filter serves as the output end of the pulse current measurement branch.
[0019] In some embodiments, the ultrasonic measurement branch includes a second amplifier, an input end of the second amplifier serves as an input end of the ultrasonic measurement branch, and an output end of the second amplifier serves as an output end of the ultrasonic measurement branch.
[0020] In some embodiments, the insulation gap simulation test includes:
[0021] Placing the pre-treated sample between the high voltage electrode and the ground electrode;
[0022] Adjust the relative humidity and ambient temperature in the metal housing, and simulate the conditional altitude by adjusting the air pressure in the metal housing, so that the sample to be tested is in the set test environment conditions;
[0023] The voltage of the test power supply is gradually increased by a step-by-step voltage-boosting method, and after each voltage boost, the oscilloscope is observed to see whether a negative pulse signal is collected, and the voltage value after the voltage boost, as well as the discharge phase and amplitude are recorded;
[0024] If a negative pulse signal is observed on the oscilloscope, record the relative humidity, ambient temperature and altitude of the environment where the sample to be tested is located at this time, and use the voltage value after the voltage boost as the corona initiation voltage of the sample to be tested under the current test environment conditions.
[0025] In some embodiments, after placing the sample to be tested in a set test environment condition, and before gradually increasing the voltage of the test power supply by using a step-by-step voltage boost method, the method further includes:
[0026] The initial voltage of the test power supply is set to zero, and the trigger threshold of the oscilloscope is set to an amplitude lower than the negative background noise.
[0027] In some embodiments, the corona onset voltage correction calculation formula is:
[0028] U c (H)=U 01 (1+K H H)
[0029] Where U c (H) is the corona onset voltage at an altitude of H, U 01 is the corona onset voltage at zero altitude, K H is the altitude correction factor of the corona onset voltage.
[0030] In a second aspect, the present disclosure provides a system for determining an altitude correction coefficient of a corona onset voltage, comprising:
[0031] An acquisition module is used to acquire test result data of insulation gap simulation tests of the sample to be tested under multiple groups of different test environment conditions, wherein the test result data includes the test environment conditions and the corona inception voltage of the sample to be tested under the test environment conditions, wherein the test environment conditions include ambient temperature, relative humidity and altitude;
[0032] A calculation module, which obtains the absolute humidity corresponding to each set of test result data according to the relative humidity and ambient temperature in the test result data;
[0033] The fitting module is used to fit the test result data with the same relative humidity according to the preset corona onset voltage correction calculation formula to obtain the altitude correction coefficient of the corona onset voltage corresponding to the tested sample at the same relative humidity and different absolute humidity.
[0034] The present disclosure provides a method and system for determining an altitude correction coefficient of a corona inception voltage. The method obtains test result data of an insulation gap simulation test under different test environment conditions, and performs fitting according to a preset corona inception voltage correction calculation formula based on the obtained test result data of the insulation gap simulation test under different test environment conditions, so as to obtain the altitude correction coefficient of the corona inception voltage of a sample to be tested under different ambient temperatures and relative humidities. Thus, the corona inception voltage of a device in a complex environment can be simulated based on the obtained altitude correction coefficient of the corona inception voltage of the sample to be tested under different ambient temperatures and relative humidities. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The present disclosure will be described in more detail below based on embodiments and with reference to the accompanying drawings:
[0036] Figure 1 A schematic flow chart of a method for determining an altitude correction coefficient of a corona onset voltage provided in an embodiment of the present disclosure;
[0037] Figure 2 It is a flow chart of the insulation gap simulation test process;
[0038] Figure 3 It is a structural schematic diagram of the insulation gap simulation test device;
[0039] Figure 4 This is a waveform diagram of a negative pulse signal collected by an oscilloscope;
[0040] Figure 5 is the characteristic diagram of the discharge pulse spectrum, where Figure 5 (a) is the discharge pulse spectrum characteristic diagram of the surface scratch sample model when the discharge voltage is 1.38V; Figure 5 (b) is the discharge pulse spectrum characteristic diagram of the surface metal burr sample model when the discharge voltage is 2.99V; Figure 5 (c) is the discharge pulse spectrum characteristic diagram of the surface insulation burr sample model when the discharge voltage is 3.31V; Figure 5 (d) is the discharge pulse spectrum characteristic diagram of the intact sample model when the discharge voltage is 3.50V;
[0041] Figure 6 is the PRPD diagram, where Figure 6 (a) PRPD diagram of the surface scratch sample model when the discharge voltage is 3.50 V; Figure 6(b) PRPD diagram of the surface metal burr sample model when the discharge voltage is 4.07V; Figure 6 (c) PRPD diagram of the surface insulation burr sample model when the discharge voltage is 4.44V; Figure 6 (d) PRPD diagram of the intact sample model when the discharge voltage is 4.91V;
[0042] Figure 7 This is a curve showing the effect of altitude on the corona inception voltage under different ambient temperatures and relative humidity.
[0043] In the drawings, the same reference numerals are used for the same components and the drawings are not drawn to scale.
[0044] Reference numerals: voltage regulator 110 , protection resistor 120 , resistor divider 130 , voltage transformer 140 , metal housing 200 , high voltage electrode 300 , ground electrode 400 , current sensor 500 , first amplifier 610 , filter 620 , second amplifier 710 , oscilloscope 800 , high-speed camera 900 . DETAILED DESCRIPTION
[0045] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, and to fully understand and implement how the present disclosure applies technical means to solve technical problems and achieve the corresponding technical effects, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only embodiments of a part of the present disclosure, not all of the embodiments. The embodiments of the present disclosure and the various features in the embodiments can be combined with each other without conflict, and the technical solutions formed are all within the scope of protection of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present disclosure.
[0046] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.
[0047] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.
[0048] Embodiment 1
[0049] Figure 1 The present invention provides a flow chart of a method for determining an altitude correction factor of a corona onset voltage according to an embodiment of the present invention. Figure 1 As shown, a method for determining an altitude correction coefficient of a corona onset voltage comprises:
[0050] Step S11, obtaining test result data of insulation gap simulation tests of the sample to be tested under multiple groups of different test environment conditions, the test result data including the test environment conditions and the corona initiation voltage of the sample to be tested under the test environment conditions, the test environment conditions including ambient temperature, relative humidity and altitude.
[0051] The samples to be tested include surface defect samples, internal defect samples and intact samples. Among them, the surface defect sample is a single-layer structure, the internal defect sample is an equal-thickness multi-layer structure, and the total thickness of the surface defect sample is equal to that of the internal defect sample. In some embodiments, the surface defect samples include surface metal burr samples, surface insulation burr samples and surface scratch samples. The surface metal burr sample is a structure in which an air gap and a copper paste are set at intervals on the surface of the intact sample; the surface insulation burr sample is a structure in which an air gap and an insulating tape are set at intervals on the surface of the intact sample; the surface scratch sample is a structure in which an air gap scratch is set at intervals on the surface of the intact sample, and the diameter (width) of the air gap scratch is 1mm, 2mm, 3mm, and 5mm respectively; the internal defect sample is a structure in which an air gap is opened in the middle layer of the intact sample.
[0052] Step S12, according to the relative humidity and ambient temperature in each set of test result data, obtain the absolute humidity corresponding to the set of test result data. Specifically, the absolute humidity is the saturated water vapor content at the ambient temperature multiplied by the relative humidity.
[0053] Step S13, fitting the test result data with the same relative humidity according to a preset corona inception voltage correction calculation formula to obtain the altitude correction coefficient of the corona inception voltage corresponding to the tested sample at the same relative humidity and different absolute humidity.
[0054] Wherein, the corona onset voltage correction calculation formula is:
[0055] U c (H)=U 01 (1+K H H)
[0056] Where U c (H) is the corona onset voltage at an altitude of H, U 01 is the corona onset voltage at zero altitude, K H is the altitude correction factor of the corona onset voltage.
[0057] In some embodiments, Figure 2 As shown, the steps of the insulation gap simulation test include:
[0058] Step S21, pre-treating the sample to be tested, specifically, the pre-treating the sample to be tested includes wiping the surface of the sample to be tested with anhydrous ethanol and drying the wiped sample to be tested. The sample to be tested can be simulated using the CIGR EmethodII model.
[0059] Step S22, placing the pre-treated sample to be tested in a set test environment condition, wherein the test environment condition includes ambient temperature, relative humidity and altitude.
[0060] Specifically, the simulation of the altitude H can be achieved by adjusting the air pressure P in the environment where the sample to be tested is located. The conversion relationship between air pressure and altitude is: The influence of the actual air pressure change at different altitudes is taken into account, and the lowest air pressure in the historical statistical data at that altitude is used for correction. The relative humidity can be adjusted by using a dehumidifier and a humidifier. The ambient temperature can be adjusted by using a refrigeration device and a heating device (such as a hot air blower).
[0061] Step S23, applying voltage to the sample to be tested in the set test environment conditions, and gradually increasing the voltage applied to the sample to be tested by a step-by-step voltage-boosting method until partial discharge is detected on the sample to be tested, and taking the voltage applied to the sample to be tested at this time as the corona initiation voltage of the sample to be tested in the current test environment conditions.
[0062] In some embodiments, the pre-treated sample is subjected to an insulation gap simulation test by a preset insulation gap simulation test device to obtain the test result data. Figure 3As shown, the insulation gap simulation test device includes a test power supply, an oscilloscope 800, a pulse current measurement branch, an ultrasonic measurement branch, a current sensor 500, a metal shell 200, and a high-voltage electrode 300 and a grounding electrode 400 arranged in the metal shell 200; the high-voltage end of the test power supply is connected to the high-voltage electrode 300, and the low-voltage end of the test power supply is connected to the grounding electrode 400; the first end of the current sensor 500 is connected to the grounding electrode 400, the second end of the current sensor 500 is connected to the input end of the pulse current measurement branch, and the output end of the pulse current measurement branch is connected to the first signal input end of the oscilloscope 800; the input end of the ultrasonic measurement branch is connected to the inner wall of the metal shell 200, and the output end of the ultrasonic measurement branch is connected to the second signal input end of the oscilloscope 800.
[0063] Specifically, the pulse current measurement branch includes a first amplifier 610 and a filter 620, the input end of the first amplifier 610 serves as the input end of the pulse current measurement branch, the output end of the first amplifier 610 is connected to the input end of the filter 620, and the output end of the filter 620 serves as the output end of the pulse current measurement branch. The ultrasonic measurement branch includes a second amplifier 710, the input end of the second amplifier 710 serves as the input end of the ultrasonic measurement branch, and the output end of the second amplifier 710 serves as the output end of the ultrasonic measurement branch. The test power supply includes a voltage regulator 110, a protective resistor 120 and a resistor divider 130. The high voltage end of the secondary winding of the voltage regulator 110 is connected to the first end of the protective resistor 120, and the second end of the protective resistor 120 serves as the high voltage end of the test power supply. The resistor divider 130 is connected between the high voltage end and the low voltage end of the secondary winding of the voltage regulator 110, and the voltage divider end of the resistor divider 130 is connected to the first end of the voltage transformer 140, and the second end of the voltage transformer 140 is grounded.
[0064] In some embodiments, the insulation gap simulation test device further includes a high-speed camera 900. The high-speed camera 900 is used to capture an instantaneous image of a partial discharge phenomenon occurring on the sample to be tested that is clamped between the high-voltage electrode 300 and the ground electrode 400.
[0065] The process of performing the insulation gap simulation test using the above insulation gap simulation test device includes:
[0066] Step S31, placing the pre-treated sample between the high voltage electrode 300 and the ground electrode 400;
[0067] Step S32, adjusting the relative humidity and ambient temperature in the metal housing 200, and adjusting the air pressure in the metal housing 200 to simulate the altitude adjustment, so that the sample to be tested is in the set test environment conditions;
[0068] Step S33, using a step-by-step voltage boosting method to gradually increase the voltage of the test power supply, and after each voltage boost, observing whether the oscilloscope 800 collects a negative pulse signal, and recording the voltage value after the voltage boost, as well as the discharge phase and amplitude;
[0069] Step S34, if it is observed that the oscilloscope 800 does not collect a negative pulse signal, the voltage of the test power supply is increased again; if it is observed that the oscilloscope 800 collects a negative pulse signal, the relative humidity, ambient temperature and altitude of the environment in which the sample to be tested is located are recorded at this time, and the voltage value after this voltage increase is used as the corona starting voltage of the sample to be tested under the current test environment conditions.
[0070] In some embodiments, step S35 is further included between step S31 and step S32, in which the initial voltage of the test power supply is set to zero and the trigger threshold of the oscilloscope 800 is set to an amplitude lower than the negative background noise.
[0071] In a specific application example, the intact sample is a disc structure with epoxy resin as a solid medium. The diameter of the intact sample is 80mm. The surface defect sample is composed of a single layer of intact samples with a thickness of 3mm, and the internal defect sample is composed of 3 layers of intact samples with a thickness of 1mm. The high-voltage electrode adopts a cylindrical copper electrode with a diameter and height of 25mm, and the grounding electrode adopts a cylindrical copper electrode with a diameter of 40mm and a height of 15mm. The preset altitude range is 200m to 4000m, the preset relative humidity range is 30% to 70%, and the preset ambient temperature range is 15℃ to 35℃. This test measured the corona inception voltage values under 9 altitudes H, namely 200m, 1000m, 1500m, 2000m, 2500m, 2800m, 3000m, 3500m and 4000m, 4 relative humidity RH, namely 30%, 45%, 60% and 70%, and 5 ambient temperatures t, namely 15℃, 20℃, 25℃, 30℃ and 35℃, for a total of 180 test environmental conditions.
[0072] Step S41, selecting the sample to be tested as a surface defect sample, an internal defect sample or a good sample, wiping the surface of the sample to be tested with anhydrous ethanol, and drying it for standby use;
[0073] Step S42, placing the dried sample to be tested between the high voltage electrode 300 and the ground electrode 400;
[0074] Step S43, adjust the relative humidity RH, ambient temperature t and altitude H in the metal housing 200 so that the sample to be tested is in the set test environment conditions. The altitude H can be achieved by adjusting the air pressure P in the environment where the sample to be tested is located. The conversion relationship between air pressure and altitude is: The influence of the actual air pressure change at different altitudes is taken into account, and the lowest air pressure in the historical statistical data at that altitude is used for correction. The relative humidity can be adjusted by using a dehumidifier and a humidifier. The ambient temperature can be adjusted by using a refrigeration device and a heating device (such as a hot air blower).
[0075] Step S44, setting the initial voltage of the test power supply to zero, and setting the trigger threshold of the oscilloscope 800 to an amplitude lower than the negative background noise.
[0076] Step S45, gradually increase the voltage of the test power supply by a step-by-step voltage-boosting method, wait for 10 seconds after each increase of 0.2 KV, observe whether the oscilloscope 800 collects a negative pulse signal, and record the voltage value after the voltage boost, as well as the discharge phase and amplitude;
[0077] Step S46, if it is observed that the oscilloscope 800 does not collect a negative pulse signal, the voltage of the test power supply is increased again; if it is observed that the oscilloscope 800 collects a negative pulse signal, the negative pulse signal is as follows Figure 4 As shown, the voltage value after the boost, the discharge phase and amplitude, as well as the relative humidity, ambient temperature and altitude of the environment in which the sample to be tested is located at this time are recorded, and the voltage value after the boost is used as the corona initiation voltage of the sample to be tested under the current test environment conditions.
[0078] Surface metal burr samples, surface insulation burr samples, surface scratch samples, intact samples and internal defect samples with different air gap sizes are respectively used as samples to be tested to perform steps S41 to S46, and the following results are obtained: Figure 5 The discharge pulse spectrum characteristic diagrams of the surface metal burr samples, surface insulation burr samples, surface scratch samples, intact samples and internal defect samples with different sizes of air gaps are shown in the figure, and the corona discharge signals collected by the oscilloscope are processed into the corresponding partial discharge phase distribution diagrams (PRPD). The PRPD diagrams corresponding to the surface metal burr samples, surface insulation burr samples, surface scratch samples, intact samples and internal defect samples with different sizes of air gaps are shown in the figure. Figure 6 shown.
[0079] Depend on Figure 5 and Figure 6It can be seen that the amplitude-frequency characteristics of different defect types on the epoxy resin surface discharge in non-uniform pressure air tend to be consistent, and the main peak frequency is around 2-3MHz. The similarities of several surface defect discharge models are that the positive pulse amplitude is much higher than the negative pulse, with obvious polarity effect, and no discharge pulse appears at 0° and 180°. The discharge phases of these surface defect discharge models are slightly different.
[0080] Under each test environment condition, the insulation gap simulation test was repeated 5 to 8 times, and the average value of the corona inception voltage obtained in each test was taken as the final corona inception voltage under the test environment condition. The test results of the corona inception voltage under 180 test environment conditions are shown in Table 1.
[0081] Table 1 shows the results of the insulation corona inception voltage between equivalent electrodes under different environmental parameters (unit: kV)
[0082]
[0083]
[0084] It can be seen from Table 1 that the relative standard deviation of the overall test result data is 0.28% to 5.23%.
[0085] Step S47, obtaining the absolute humidity corresponding to each set of test result data according to the relative humidity and ambient temperature in the test result data.
[0086] Step S48, fitting the test result data with the same relative humidity in Table 1 according to the preset corona onset voltage correction calculation formula to obtain the altitude correction coefficient K of the corona onset voltage corresponding to the sample under test at the same relative humidity and different absolute humidity H , and the corona onset voltage U of the sample to be tested at zero altitude 01 The corona onset voltage correction calculation formula is:
[0087] U c (H)=U 01 (1+K H H)
[0088] Where U c (H) is the corona onset voltage at an altitude of H, U 01 is the corona onset voltage at zero altitude, K H is the altitude correction factor of the corona onset voltage.
[0089] The altitude correction coefficient determined by fitting and the corona onset voltage at zero altitude are used to update the corona onset voltage correction calculation formula to obtain the corona onset voltage correction calculation formula under different ambient temperatures and relative humidity. Then, the updated corona onset voltage correction calculation formula is used to fit the following: Figure 7 The curve of the corona onset voltage under different relative humidity is affected by altitude. Figure 7 The horizontal axis is the altitude, and the vertical axis is the corona inception voltage (corona inception voltage). Figure 7 Each point represents test result data. Figure 7 (a) Figure 7 (b) Figure 7 (c) Figure 7 (d) Corona onset voltage affected by altitude for relative humidity RH of 30%, 45%, 60%, and 70%, respectively. Absolute humidity = relative humidity × (saturated water vapor pressure / gas constant) × temperature. Figure 7 Each of the corona onset voltage curves in the graph represents the corona onset voltage curve under the same relative humidity and different absolute humidity. Figure 7 It can be seen that as the absolute humidity h a With the increase of altitude, the decrease of corona onset voltage is weakened.
[0090] Embodiment 2
[0091] This embodiment provides a system for determining an altitude correction coefficient of a corona onset voltage, comprising:
[0092] An acquisition module is used to acquire test result data of insulation gap simulation tests of the sample to be tested under multiple groups of different test environment conditions, wherein the test result data includes the test environment conditions and the corona inception voltage of the sample to be tested under the test environment conditions, wherein the test environment conditions include ambient temperature, relative humidity and altitude;
[0093] A calculation module, which obtains the absolute humidity corresponding to each set of test result data according to the relative humidity and ambient temperature in the test result data;
[0094] The fitting module is used to fit the test result data with the same relative humidity according to the preset corona onset voltage correction calculation formula to obtain the altitude correction coefficient of the corona onset voltage corresponding to the tested sample at the same relative humidity and different absolute humidity.
[0095] The specific implementation details of the system provided in this embodiment refer to the first embodiment and will not be repeated here.
[0096] The system provided in this embodiment obtains test result data of insulation gap simulation tests of the sample to be tested under multiple groups of different test environment conditions, the test result data including the test environment conditions and the corona inception voltage of the sample to be tested under the test environment conditions, the test environment conditions including ambient temperature, relative humidity and altitude, and obtains the absolute humidity corresponding to the group of test result data according to the relative humidity and ambient temperature in each group of test result data; the test result data with the same relative humidity are fitted according to a preset corona inception voltage correction calculation formula to obtain the altitude correction coefficient of the corona inception voltage corresponding to the sample to be tested at the same relative humidity and different absolute humidity, so that the corona inception voltage of the device in a complex environment can be simulated according to the obtained altitude correction coefficient of the corona inception voltage corresponding to the sample to be tested at different relative humidity and absolute humidity.
[0097] Embodiment 3
[0098] On the basis of the above embodiments, this embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method described in the above embodiments.
[0099] In some implementations of this embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in the above embodiment are implemented.
[0100] In some implementations of this embodiment, a computer program product is provided, including a computer program / instructions, and when the computer program is executed by a processor, the steps of the method described in the above embodiment are implemented.
[0101] The processor may include, but is not limited to, one or more processors or microprocessors, etc. Each processor may be an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a controller, a microcontroller, a microprocessor or other electronic components to execute the methods in the above embodiments.
[0102] The computer-readable storage medium may be implemented by any type of volatile or non-volatile storage device or a combination thereof, and the computer-readable storage medium may include but is not limited to, for example, random access memory (RAM), read-only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, computer storage media (e.g., hard disk, floppy disk, solid-state drive, removable disk, CD-ROM, DVD-ROM, Blu-ray disc, etc.).
[0103] The computer-readable storage medium may also store at least one computer executable program / instruction, which may be, for example, a computer-readable instruction. The computer-readable storage medium includes, but is not limited to, for example, a volatile memory and / or a non-volatile memory. The volatile memory may include, for example, a random access memory (RAM) and / or a cache memory (cache), etc. The computer-readable storage medium may include, for example, a read-only memory (ROM), a hard disk, a flash memory, etc. For example, a non-transitory computer-readable storage medium may be connected to a computing device such as a computer, and then, when the computing device runs the computer-readable instructions stored on the computer-readable storage medium, the various methods described above may be performed.
[0104] In addition, the computer device may also include (but not limited to) a data bus, an input / output (I / O) bus, a display, and input / output devices (eg, keyboard, mouse, speaker, etc.), etc.
[0105] The processor may communicate with external devices via an I / O bus via a wired or wireless network.
[0106] In one embodiment, the at least one computer executable instruction may also be compiled into or constitute a software product / computer program product, wherein one or more computer executable instructions are executed by a processor to perform the various functions and / or method steps in the embodiments described in the present technology.
[0107] In the embodiments provided in the present disclosure, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the above-mentioned module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.
[0108] It should be noted that in the present disclosure, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element limited by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.
[0109] Although the embodiments disclosed in the present disclosure are as above, the above contents are only embodiments adopted for facilitating the understanding of the present disclosure and are not intended to limit the present disclosure. Any technician in the technical field to which the present disclosure belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present disclosure, but the scope of patent protection of the present disclosure shall still be subject to the scope defined in the attached claims.
Claims
1. A method for determining an altitude correction coefficient of a corona onset voltage, characterized in that: include: Acquire test result data of insulation gap simulation tests of the sample to be tested under multiple groups of different test environment conditions, wherein the test result data includes the test environment conditions and the corona inception voltage of the sample to be tested under the test environment conditions, wherein the test environment conditions include ambient temperature, relative humidity and altitude; According to the relative humidity and ambient temperature in each group of test result data, the absolute humidity corresponding to the group of test result data is obtained; The test result data with the same relative humidity were fitted according to the preset corona onset voltage correction calculation formula to obtain the altitude correction coefficient of the corona onset voltage corresponding to the tested sample at the same relative humidity and different absolute humidity.
2. The method according to claim 1, characterized in that The steps of the insulation gap simulation test include: Pre-treat the samples to be tested; Place the pre-treated samples under the set test environment conditions; A voltage is applied to the sample to be tested in the set test environment conditions, and the voltage applied to the sample to be tested is gradually increased by a step-by-step voltage-boosting method until partial discharge is detected on the sample to be tested. The voltage applied to the sample to be tested at this time is used as the corona initiation voltage of the sample to be tested in the current test environment conditions.
3. The method according to claim 2, characterized in that Pre-treat the samples to be tested, including: The surface of the sample to be tested is wiped with anhydrous ethanol, and the wiped sample to be tested is dried.
4. The method according to claim 2, characterized in that: The pre-treated sample to be tested is subjected to an insulation gap simulation test through a preset insulation gap simulation test device to obtain the test result data, wherein the insulation gap simulation test device includes a test power supply, an oscilloscope, a pulse current measurement branch, an ultrasonic measurement branch, a current sensor, a metal shell, and a high-voltage electrode and a grounding electrode arranged in the metal shell; The high voltage end of the test power supply is connected to the high voltage electrode, and the low voltage end of the test power supply is connected to the ground electrode; The first end of the current sensor is connected to the ground electrode, the second end of the current sensor is connected to the input end of the pulse current measurement branch, and the output end of the pulse current measurement branch is connected to the first signal input end of the oscilloscope; The input end of the ultrasonic measurement branch is connected to the inner wall of the metal shell, and the output end of the ultrasonic measurement branch is connected to the second signal input end of the oscilloscope.
5. The method according to claim 4, characterized in that The pulse current measurement branch includes a first amplifier and a filter, the input end of the first amplifier serves as the input end of the pulse current measurement branch, the output end of the first amplifier is connected to the input end of the filter, and the output end of the filter serves as the output end of the pulse current measurement branch.
6. The method according to claim 4, characterized in that The ultrasonic measurement branch includes a second amplifier, an input end of the second amplifier serves as an input end of the ultrasonic measurement branch, and an output end of the second amplifier serves as an output end of the ultrasonic measurement branch.
7. The method according to claim 4, characterized in that The insulation gap simulation test includes: Placing the pre-treated sample between the high voltage electrode and the ground electrode; Adjust the relative humidity and ambient temperature inside the metal casing, and simulate the altitude adjustment by adjusting the air pressure inside the metal casing, so that the sample to be tested is in the set test environment conditions; The voltage of the test power supply is gradually increased by a step-by-step voltage-boosting method, and after each voltage boost, the oscilloscope is observed to see whether a negative pulse signal is collected, and the voltage value after the voltage boost, as well as the discharge phase and amplitude are recorded; If a negative pulse signal is observed on the oscilloscope, record the relative humidity, ambient temperature and altitude of the environment where the sample to be tested is located at this time, and use the voltage value after the voltage boost as the corona initiation voltage of the sample to be tested under the current test environment conditions.
8. The method according to claim 7, characterized in that After placing the sample to be tested in the set test environment conditions, and before gradually increasing the voltage of the test power supply by using a step-by-step voltage-boosting method, the method further includes: The initial voltage of the test power supply is set to zero, and the trigger threshold of the oscilloscope is set to an amplitude lower than the negative background noise.
9. The method according to claim 1, characterized in that: The corona onset voltage correction calculation formula is: U c (H)=U 01 (1+K H H) Where U c (H) is the corona onset voltage at an altitude of H, U 01 is the corona onset voltage at zero altitude, K H is the altitude correction factor of the corona onset voltage.
10. A system for determining the altitude correction factor of the corona onset voltage, characterized in that: include: An acquisition module is used to acquire test result data of insulation gap simulation tests of the sample to be tested under multiple groups of different test environment conditions, wherein the test result data includes the test environment conditions and the corona inception voltage of the sample to be tested under the test environment conditions, wherein the test environment conditions include ambient temperature, relative humidity and altitude; A calculation module, which obtains the absolute humidity corresponding to each set of test result data according to the relative humidity and ambient temperature in the test result data; The fitting module is used to fit the test result data with the same relative humidity according to the preset corona onset voltage correction calculation formula to obtain the altitude correction coefficient of the corona onset voltage corresponding to the tested sample at the same relative humidity and different absolute humidity.