Equivalent experimental method for pressure generated by arc discharge in transformer oil

Abstract

Disclosed is an equivalent experimental method for pressure generated by arc discharge in transformer oil. In the method, gas is injected into an oil tank filled with transformer oil, and the pressure in the oil tank is measured to obtain the steady-state pressure in the oil tank. p s ; Determine the temperature of the injected gas. If it is room temperature gas, then use the peak temperature of the gas production T max Calculate the equivalent peak pressure of the arc discharge p max If the temperature of the injected gas is equal to the temperature of the arc generating gas, the peak pressure generated by the injected gas is the peak pressure of the equivalent arc discharge. p max , after the injected gas is cooled to room temperature, the steady-state pressure in the tank is p s ;Measure the volume of injected gas V g ; Calculate the equivalent arc discharge energy based on the relationship between gas volume and arc energy E arc ; Compare the arc discharge energy E arc The pressure waveform generated by the discharge and the pressure waveform of the equivalent experiment are compared to verify the feasibility of the equivalent method.

Description

Technical Field

[0001] The invention relates to the technical field of transformer oil arc discharge, in particular to an equivalent experimental method for pressure generated by arc discharge in transformer oil. Background Art

[0002] Arc discharge in transformer oil generates gas, which will increase the pressure in the oil tank, further leading to oil tank rupture or even explosion and fire. The mechanism of pressure increase caused by arc discharge in transformer oil is the generation of high-temperature gas. Arc discharge experiments are expensive and risky, and because of the high energy and high power after internal faults in UHV equipment, even the experimental station with the largest experimental capacity level cannot reach the level under real faults. Therefore, it is necessary to consider equivalent experimental methods for arc discharge and verify the equivalence of equivalent experimental methods under feasible experimental conditions.

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

[0004] The arc discharge experiment has high cost and high risk, and the discharge experiment capacity is insufficient, and it cannot simulate the fault level of the UHV transformer. This disclosure provides an equivalent experimental method for the pressure generated by arc discharge in transformer oil. Based on the equivalent experimental method proposed in this article, the arc discharge experiment operation can be simplified, the discharge experiment cost can be reduced, and when the discharge experiment capacity is insufficient, in order to simulate the ability level of arc discharge inside the UHV transformer, an equivalent experiment needs to be carried out.

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

[0006] The present invention discloses an equivalent experimental method for pressure generated by arc discharge in transformer oil, comprising the following steps:

[0007] Inject gas into the oil tank filled with transformer oil and measure the pressure inside the oil tank to obtain the steady-state pressure inside the oil tank. p s ;

[0008] Determine the temperature of the injected gas. If it is room temperature gas, then use the peak temperature of the gas produced to determine the temperature of the injected gas. T max Calculate the peak pressure of the arc discharge p max If the temperature of the injected gas is equal to the temperature of the arc generating gas, the peak pressure generated by the injected gas is the peak pressure of the equivalent arc discharge. p max , after the injected gas is cooled to room temperature, the steady-state pressure in the tank is p s ;

[0009] Measuring the volume of injected gas V g ;

[0010] According to the relationship between gas volume and arc energy, the equivalent arc discharge energy is calculated. E arc ;

[0011] Compare the arc discharge energy E arc The pressure waveform generated when the pressure is increased verifies the feasibility of the equivalent method.

[0012] In the method, the oil tank is in a sealed state and is provided with a pressure sensor for measuring the pressure change in the oil tank.

[0013] In the method, the water displacement gas collection method is used to calculate the gas volume.

[0014] In the method described, the relationship between arc discharge energy and gas production is 70~135mL / kJ. V g Calculate the energy of the equivalent arc discharge experiment E arc .

[0015] In the method described, the arc gas generation temperature reaches 2000K.

[0016] In addition, the present invention discloses an equivalent experimental system for pressure generated by arc discharge in transformer oil, which comprises:

[0017] The injection device is used to inject gas into the oil tank filled with transformer oil and measure the pressure in the oil tank to obtain the steady-state pressure in the oil tank. p s ;

[0018] A processing device based on judgment is used to judge the temperature of the injected gas. If it is room temperature gas, it is based on the peak temperature of the gas production. T max Calculate the equivalent peak pressure of the arc discharge p max If the temperature of the injected gas is equal to the temperature of the arc generating gas, the peak pressure generated by the injected gas is the peak pressure of the equivalent arc discharge. p max , after the injected gas is cooled to room temperature, the steady-state pressure in the tank is p s ;

[0019] Measuring device for measuring the volume of injected gas V g ;

[0020] A calculation device for calculating the equivalent arc discharge energy based on the relationship between the gas volume and the arc energy E arc ;

[0021] A comparison device is used to compare the arc discharge energy E arc The pressure waveform generated by the discharge and the pressure waveform of the equivalent experiment are compared to verify the feasibility of the equivalent method.

[0022] In addition, the present invention also discloses a computer storage medium, wherein the storage medium includes computer instructions, and when the computer is run on the computer, the computer executes any of the methods described above.

[0023] In addition, the present invention also discloses an electronic device, wherein the electronic device comprises:

[0024] A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein:

[0025] When the processor executes the program, any of the methods described above is implemented.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] In view of the high cost and high risk of arc discharge experiments, the insufficient discharge experiment capacity and the inability to simulate the fault level of ultra-high voltage transformers, the present invention provides an equivalent experimental method for generating pressure by arc discharge in transformer oil. Based on the equivalent experimental method proposed in this article, the arc discharge experiment operation can be simplified and the discharge experiment cost can be reduced. When the discharge experiment capacity is insufficient, an equivalent experiment needs to be carried out to simulate the ability level of arc discharge inside the ultra-high voltage transformer.

[0028] The above description is only an overview of the technical solution of the present invention. In order to make the technical means of the present invention clearer and to achieve the extent that those skilled in the art can implement it according to the contents of the specification, and in order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are exemplified below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] By reading the detailed description of the preferred specific embodiments below, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The drawings in the specification are only for the purpose of illustrating the preferred embodiments and are not considered to be limitations of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work. Moreover, the same reference numerals are used to represent the same components throughout the drawings.

[0030] In the attached picture:

[0031] Figure 1 It is a schematic diagram of the flow of an equivalent experimental method for pressure generated by arc discharge in transformer oil;

[0032] Figure 2 It is a schematic diagram of the arc discharge equivalent experimental platform;

[0033] Figure 3 It is a schematic diagram comparing the arc discharge equivalent experiment results with the discharge experiment results.

[0034] The present invention is further explained below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0035] The specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0036] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the attached claims.

[0037] To facilitate understanding of the embodiments of the present invention, several specific embodiments will be further explained below with reference to the accompanying drawings, and each of the accompanying drawings does not constitute a limitation on the embodiments of the present invention.

[0038] For a better understanding, Figures 1 to 3 As shown, an equivalent experimental method for the pressure generated by arc discharge in transformer oil includes:

[0039] In a preferred embodiment of the method, gas is injected into an oil tank filled with transformer oil, and a pressure sensor is used to measure the pressure in the oil tank to obtain a steady-state pressure in the oil tank. p s Furthermore, the steady-state pressure in the fuel tank p s The value is the value after reaching stability. The oil tank is in a closed state, and is provided with a pressure sensor for measuring the pressure change in the oil tank. The low-frequency response performance of the pressure sensor should meet the needs of steady-state pressure measurement in the oil tank, and a piezoresistive pressure sensor should generally be used. The steady-state pressure in the oil tank refers to the value when the pressure in the oil tank reaches stability after the gas injection is completed. In this implementation case, a high-pressure gas source is used as the pressure source for the equivalent experiment, and an electromagnetic valve is used to achieve remote control of the equivalent experiment. When the solenoid valve is opened, under the action of the pressure difference, compressed gas enters the experimental oil tank from the high-pressure gas source, and a pressure sensor and a data acquisition system are used to record the pressure changes of the equivalent experiment. Figure 2 shown.

[0040] Determine the temperature of the injected gas. If it is room temperature gas, then use the peak temperature of the gas produced to determine the temperature of the injected gas. T max Using the ideal gas state equation, calculate the peak pressure of the arc discharge If the temperature of the injected gas is equal to the temperature of the arc-generating gas, the instantaneous peak pressure generated in the oil tank after the gas is injected is measured by a high-frequency pressure sensor, which is the equivalent peak pressure of the arc discharge. p max , after the injected gas is cooled to room temperature, the steady-state pressure in the tank is p s In this embodiment, the temperature of the injected gas is room temperature gas. According to the literature, the peak temperature of the gas is T max It is 2000K.

[0041] Measuring the volume of injected gas V g ; Since the injected gas is insoluble in water and oil, the volume of the injected gas can be calculated using the drainage gas collection method. In this embodiment, the volume of the room temperature gas injected using the high pressure gas source is V g =410mL, producing steady-state pressure p s =118kPa.

[0042] According to the relationship between gas volume and arc energy, the relationship between arc discharge energy and gas production is 70~135mL / kJ. V g Calculate the energy of the equivalent arc discharge experiment E arc =5.4kJ.

[0043] Compare the arc discharge energy E arc The pressure waveform generated during the discharge experiment verifies the feasibility of the equivalent method. The pressure change waveform in the oil tank during the discharge experiment is measured using a pressure sensor. Compare the pressure peak value obtained according to the equivalent experiment p max With steady-state pressure p s , and the pressure peak and steady-state pressure obtained from the discharge experiment, as well as the rising experiment of the two pressure waveforms. If the above indicators are within the acceptable error range, the equivalent experiment is considered to be equivalent. In the experiment, the arc energy was measured because the exact value of the arc discharge energy could not be controlled. E arc =5.3kJ discharge experiment. The pressure change waveform in the oil tank during the discharge experiment was measured using a pressure sensor. Compare the pressure peak value obtained from the equivalent experiment p max With steady-state pressure p s , and the pressure peak and steady-state pressure obtained in the discharge experiment, as well as the rising experiment of the two pressure waveforms. If the above indicators are within the acceptable error range, the equivalent experiment is considered to be equivalent. The pressure curve measured in the discharge experiment and the pressure curve of the equivalent experiment are compared. Figure 3 shown.

[0044] Furthermore, in another embodiment, the present invention further discloses a computer storage medium, wherein the storage medium includes computer instructions, and when the computer is run on the computer, the computer executes any of the methods described above.

[0045] In addition, in another embodiment, the present invention further discloses an electronic device, wherein the electronic device includes:

[0046] A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein:

[0047] When the processor executes the program, any of the methods described above is implemented.

[0048] In addition, in another embodiment, the present invention discloses an equivalent experimental system for pressure generated by arc discharge in transformer oil, which comprises:

[0049] The injection device is used to inject gas into the oil tank filled with transformer oil and measure the pressure in the oil tank to obtain the steady-state pressure in the oil tank. p s ;

[0050] A processing device based on judgment is used to judge the temperature of the injected gas. If it is room temperature gas, it is based on the peak temperature of the gas production. T max Calculate the equivalent peak pressure of the arc discharge p max If the temperature of the injected gas is equal to the temperature of the arc generating gas, the peak pressure generated by the injected gas is the peak pressure of the equivalent arc discharge. p max , after the injected gas is cooled to room temperature, the steady-state pressure in the tank is p s ;

[0051] Measuring device for measuring the volume of injected gas V g ;

[0052] A calculation device for calculating the equivalent arc discharge energy based on the relationship between the gas volume and the arc energy E arc ;

[0053] A comparison device is used to compare the arc discharge energy E arc The pressure waveform generated by the discharge and the pressure waveform of the equivalent experiment are compared to verify the feasibility of the equivalent method.

[0054] In another embodiment, for the system, wherein,

[0055] The oil tank is in a sealed state and is provided with a pressure sensor for measuring the pressure change in the oil tank, and the low-frequency response of the pressure sensor needs to meet the requirements of steady-state pressure measurement.

[0056] In another embodiment, for the system, wherein,

[0057] The measuring device uses a water displacement gas collection method to calculate the gas volume.

[0058] In another embodiment, for the system, wherein,

[0059] The calculation device is based on the injected gas volume V g Calculate the energy of the equivalent arc discharge experiment E arc .

[0060] In a more specific embodiment,

[0061] The pressure changes caused by arc discharge are simulated by injecting gas into the transformer tank, and the effectiveness of the equivalent method is verified by comparing the pressure waveforms generated by actual arc discharge and equivalent experiments.

[0062] The experimental equipment includes:

[0063] Oil tank: a sealed oil tank filled with transformer oil;

[0064] Injection device: used to inject gas into the fuel tank;

[0065] Pressure sensor: installed on the fuel tank to measure the pressure change in the fuel tank;

[0066] Temperature sensor: used to measure the temperature of injected gas;

[0067] Drainage gas collection device: used to collect and measure the volume of injected gas;

[0068] Data acquisition system: records the data from the pressure sensor.

[0069] The specific experimental steps are as follows:

[0070] 1) Preparation stage:

[0071] Fill the tank completely with transformer oil and ensure that the tank is airtight;

[0072] Install the pressure sensor and ensure that its low-frequency response can meet the steady-state pressure measurement requirements;

[0073] Prepare the injection device and drainage and gas collecting device.

[0074] 2) Injection of gas:

[0075] Inject a certain amount of gas into the fuel tank, which can be air or other inert gas;

[0076] The temperature of the injected gas is measured using a temperature sensor.

[0077] 3) Measuring steady-state pressure:

[0078] If the injected gas is room temperature gas, record the initial pressure in the tank as the steady-state pressure;

[0079] If the injected gas temperature is equal to the temperature of the arc generating gas, record the maximum pressure after the gas is injected as the peak pressure, and record the steady-state pressure after the gas cools to room temperature.

[0080] 4) Gas volume measurement:

[0081] The volume of injected gas is calculated by drainage gas collection method;

[0082] Based on the relationship between gas volume and arc energy, the equivalent arc discharge energy is calculated.

[0083] 5) Data analysis:

[0084] The pressure waveform produced by actual arc discharge under the same arc discharge energy conditions is compared with the pressure waveform of the equivalent experiment to verify the feasibility of the equivalent method.

[0085] The following exemplary data are obtained:

[0086] The parameters are set as follows:

[0087] Fuel tank specifications: capacity 100 liters, diameter 50 cm;

[0088] Transformer oil: density is about 880kg / m³;

[0089] Gas injection volume: 10 liters;

[0090] Gas temperature: 20 degrees Celsius (normal temperature);

[0091] The data collection is as follows:

[0092] Initial steady-state pressure: Before gas is injected, the pressure in the tank is 1 atmosphere (101.325 kPa).

[0093] The pressure changes after gas injection are as follows:

[0094] After the gas was injected, the pressure in the tank rose to 110 kPa;

[0095] After the gas cooled to room temperature, the pressure dropped back to 102 kPa.

[0096] For the above embodiment, based on the relationship between the injected gas volume (10 liters) and the arc energy, assuming that the relationship between the arc discharge energy and the gas production is 100mL / kJ, that is, each liter of gas is equivalent to 10 kilojoules of arc energy, then 10 liters of gas is equivalent to 10,000 joules of arc energy.

[0097] For the above embodiments, the pressure waveforms are compared as follows:

[0098] The pressure waveform generated by the actual arc discharge: the peak pressure reaches 110 kPa, and then gradually drops to 101.325 kPa.

[0099] Pressure waveform produced by the equivalent experiment: the peak pressure reaches 110 kPa and then cools to 102 kPa.

[0100] Therefore, by comparing the pressure waveform generated by the actual arc discharge with the pressure waveform of the equivalent experiment, it can be seen that the two have good consistency in peak pressure and pressure drop trend, which verifies the feasibility of the equivalent method.

[0101] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. An equivalent experimental method for pressure generated by arc discharge in transformer oil, characterized in that: It includes the following steps, Inject gas into the oil tank filled with transformer oil and measure the pressure inside the oil tank to obtain the steady-state pressure inside the oil tank. p s ; Determine the temperature of the injected gas. If it is room temperature gas, then use the peak temperature of the gas produced to determine the temperature of the injected gas. T max Calculate the equivalent peak pressure of the arc discharge p max If the temperature of the injected gas is equal to the temperature of the arc generating gas, the peak pressure generated by the injected gas is the peak pressure of the equivalent arc discharge. p max , after the injected gas is cooled to room temperature, the steady-state pressure in the tank is p s ; Measuring the volume of injected gas V g ; According to the relationship between gas volume and arc energy, the equivalent arc discharge energy is calculated. E arc ; Compare the arc discharge energy E arc The pressure waveform generated by the discharge and the pressure waveform of the equivalent experiment are compared to verify the feasibility of the equivalent method; in, According to the volume of injected gas V g Calculate the energy of the equivalent arc discharge experiment E arc .

2. The method according to claim 1, characterized in that The oil tank is in a sealed state and is provided with a pressure sensor for measuring the pressure change in the oil tank, and the low-frequency response of the pressure sensor needs to meet the requirements of steady-state pressure measurement.

3. The method according to claim 1, characterized in that The gas volume was calculated using the drainage gas collection method.

4. An equivalent experimental system for pressure generated by arc discharge in transformer oil, characterized in that: It includes: The injection device is used to inject gas into the oil tank filled with transformer oil and measure the pressure in the oil tank to obtain the steady-state pressure in the oil tank. p s ; A processing device based on judgment is used to judge the temperature of the injected gas. If it is room temperature gas, it is based on the peak temperature of the gas production. T max Calculate the equivalent peak pressure of the arc discharge p max If the temperature of the injected gas is equal to the temperature of the arc generating gas, the peak pressure generated by the injected gas is the peak pressure of the equivalent arc discharge. p max , after the injected gas is cooled to room temperature, the steady-state pressure in the tank is p s ; Measuring device for measuring the volume of injected gas V g ; A calculation device for calculating the equivalent arc discharge energy based on the relationship between the gas volume and the arc energy E arc ; A comparison device is used to compare the arc discharge energy E arc The pressure waveform generated by the discharge and the pressure waveform of the equivalent experiment are compared to verify the feasibility of the equivalent method; in, The calculation device is based on the injected gas volume V g Calculate the energy of the equivalent arc discharge experiment E arc .

5. The system according to claim 4, characterized in that The oil tank is in a sealed state and is provided with a pressure sensor for measuring the pressure change in the oil tank, and the low-frequency response of the pressure sensor needs to meet the requirements of steady-state pressure measurement.

6. The system according to claim 4, characterized in that The measuring device uses a water displacement gas collection method to calculate the gas volume.

7. A computer storage medium, wherein: The storage medium includes computer instructions, which, when executed on a computer, enable the computer to execute the method according to any one of claims 1 to 3.

8. An electronic device, wherein: The electronic device comprises: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the method according to any one of claims 1 to 3 is implemented.

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