System and method for testing mechanical strength of transformer oil tank under arc discharge simulation

Abstract

The invention discloses a system and a method for testing the mechanical strength of a transformer oil tank under arc discharge simulation, and the system comprises the components of a tested transformer oil tank which is used for accommodating a liquid medium; the pulse power supply is used for generating pulse voltage and supplying power to the electrodes; the electrodes are arranged in the tested transformer oil tank, are connected with the pulse power supply and are used for introducing pulse voltage and generating pulse arc discharge between the two electrodes so as to simulate the arc discharge fault of the transformer; the pressure detection probes are arranged at different positions in the tested transformer oil tank and are used for detecting the intensity of pressure waves generated by arc discharge; and the conductive connecting piece is used for connecting the electrode and the tested transformer oil tank. According to the test system and method provided by the embodiment of the invention, the accuracy and reliability of test data can be remarkably improved, and the mechanical strength of the transformer oil tank can be more comprehensively evaluated.

Description

Technical Field

[0001] The present invention relates to the technical field of transformers, and in particular to a system and method for testing the mechanical strength of a transformer oil tank under arc discharge simulation. Background Art

[0002] As a crucial component of the power system, transformers bear the heavy responsibility of transmitting and distributing electrical energy. They not only play a key role in voltage conversion in transmission and substations, but also improve the efficiency and stability of the power grid by optimizing power transmission, ensuring that electricity can be effectively transmitted from power plants to end users. Internal short-circuit arc faults are one of the most serious transformer failures, and reports of transformer explosions have become common in recent years.

[0003] When an arc fault occurs inside a transformer, the arc triggers the chemical decomposition and physical vaporization of the transformer oil. The released gases absorb the energy of the arc, causing a sharp rise in local temperature and accompanying volume expansion. This expansion process is usually somewhat suppressed by the presence of transformer oil. The persistent pressure differential creates a series of pressure waves, the cumulative effect of which can lead to high pressure inside the transformer. Once the pressure on the transformer tank exceeds its maximum mechanical strength, it can rupture and even explode.

[0004] Currently, the test method for the mechanical strength of transformer oil tanks mainly adopts a static or steady-state method, which increases the internal pressure by injecting gas or liquid. This method cannot truly simulate the transient pressure changes when arc discharge occurs inside the transformer, and fails to fully reflect the actual impact of the arc discharge process inside the transformer on the mechanical strength of the oil tank. Summary of the Invention

[0005] In view of this, the present invention proposes a system and method for testing the mechanical strength of a transformer oil tank under arc discharge simulation, aiming to solve one or more of the technical problems mentioned in the above background technology section.

[0006] In a first aspect, an embodiment of the present invention provides a system for testing the mechanical strength of a transformer tank under arc discharge simulation, the test system comprising: a tested transformer tank for containing a liquid medium; a pulse power supply for generating a pulse voltage to power an electrode; electrodes disposed in the tested transformer tank and connected to the pulse power supply for applying a pulse voltage to generate a pulse arc discharge between two electrodes to simulate an arc discharge fault in the transformer; pressure detection probes disposed at different positions in the tested transformer tank for detecting the intensity of the pressure wave generated by the arc discharge; and a conductive connector for connecting the electrodes to the tested transformer tank.

[0007] Further, the electrodes include a high-voltage electrode and a low-voltage electrode, which are respectively connected to the high-voltage side two-phase bushings of the transformer under test tank.

[0008] Further, the test system further includes: an electrode adjusting device, which is arranged between the high-voltage side two-phase bushings of the transformer under test tank, and includes an adjusting rod and a limit bolt; wherein, the adjusting rod is used to adjust the distance between the high-voltage electrode and the low-voltage electrode to meet the requirements of different test conditions.

[0009] Further, the electrodes adopt a tip-tip structure, a tip-plate structure or a plate-plate structure.

[0010] Further, the pulse power supply includes a Marx impulse voltage generator, which includes: a voltage regulator, a silicon stack, a current-limiting resistor, a capacitor bank and a trigger gap; wherein, the output end of the voltage regulator is sequentially connected to the silicon stack, the current-limiting resistor, the capacitor bank and the trigger gap.

[0011] Further, the pulse power supply further includes: a voltage divider, with both ends respectively connected to the two electrodes, for measuring the discharge voltage between the electrodes; a Rogowski coil set, which is arranged on the low-voltage output line, for measuring the discharge current signal between the electrodes and generating a proportional voltage signal.

[0012] Further, the test system further includes: a first oscilloscope, which is used to display the signal detected by the pressure detection probe.

[0013] Further, it is characterized in that the test system further includes: a second oscilloscope, which is used to display the signals measured by the voltage divider and the Rogowski coil set.

[0014] In a second aspect, an embodiment of the present invention further provides a method for testing the mechanical strength of a transformer tank under arc discharge simulation, which is applied to the test system for the mechanical strength of a transformer tank under arc discharge simulation provided in each of the above embodiments. The test method includes: injecting a liquid medium into the transformer tank under test and installing the electrodes; using a pulse power supply to supply power to the electrodes to simulate an arc discharge fault occurring in the transformer; collecting and recording the pressure wave intensity generated by the arc discharge detected by the pressure detection probe; checking the condition of the transformer tank under test after the discharge, and judging the structural strength of the transformer tank under test according to the inspection situation.

[0015] Further, the inspection situation includes whether the tank of the transformer under test is ruptured and the range of the flying debris after the tank of the test transformer is ruptured. Judging the structural strength of the tank of the transformer under test according to the inspection situation includes: if the tank of the transformer is not ruptured, or although it is ruptured but all the flying debris is contained within the defined area, it can be determined that the structural strength of the tank of the transformer under test meets the requirements; if the tank of the transformer is ruptured and the flying debris exceeds the defined area, it is determined that the structural strength of the tank of the transformer under test does not meet the requirements.

[0016] The test system and method for the mechanical strength of a transformer tank under arc discharge simulation provided by the embodiments of the present invention supply a pulsed voltage to an electrode through a pulsed power supply to generate pulsed arc discharge between two electrodes, can truly simulate the arc discharge phenomenon under actual operating conditions, truly restore the transient pressure change, and significantly improve the accuracy and reliability of test data; by detecting the intensity of the pressure wave generated by arc discharge with pressure detection probes arranged at different positions in the tank of the transformer under test, the mechanical strength of the transformer tank can be evaluated more comprehensively, and the possible weak points of the tank under different working conditions can be revealed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Shows a schematic structural diagram of a test system for the mechanical strength of a transformer tank under arc discharge simulation according to an embodiment of the present invention;

[0018] Figure 2 Shows an exemplary flowchart of a test method for the mechanical strength of a transformer tank under arc discharge simulation according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] Now refer to the drawings to introduce the exemplary embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely, and to fully convey the scope of the present invention to those skilled in the art. The terms in the exemplary embodiments shown in the drawings are not limitations on the present invention. In the drawings, the same unit / element uses the same reference numeral.

[0020] Unless otherwise specified, the terms (including scientific and technical terms) used herein have the ordinary meaning understood by those skilled in the art. In addition, it can be understood that the terms defined in the commonly used dictionary should be understood to have a meaning consistent with the context of their related fields, and should not be understood as idealized or overly formal meanings.

[0021] Figure 1 Shows a schematic structural diagram of a test system for the mechanical strength of a transformer tank under arc discharge simulation according to an embodiment of the present invention.

[0022] As Figure 1 shown, the test system includes:

[0023] The test transformer tank 101, which is used to contain a liquid medium;

[0024] The pulse power supply 102, which is used to generate a pulse voltage to supply power to the electrodes;

[0025] The electrodes 103, which are arranged in the test transformer tank and connected to the pulse power supply, are used to apply a pulse voltage to generate a pulsed arc discharge between the two electrodes, so as to simulate the arc discharge fault of the transformer;

[0026] The pressure detection probes 104, which are arranged at different positions in the test transformer tank, are used to detect the intensity of the pressure wave generated by the arc discharge;

[0027] The conductive connecting piece 105, which is used to connect the electrodes and the test transformer tank.

[0028] Specifically, the test transformer tank is an actual transformer tank, without changing the structure of the transformer tank, and the transformer tank is a sealed structure, ensuring the authenticity and accuracy of the measured pressure wave, reducing the test cost and improving the efficiency.

[0029] The liquid medium contained in the test transformer tank can be water or other liquid media. The test uses the test method of intrinsic breakdown to simulate the voltage breakdown of liquid media such as water in actual situations. When the voltage rises to a certain level, the liquid media such as water cannot prevent the current from passing through, thus causing breakdown.

[0030] The pulse power supply can generate a pulse voltage signal with a short duration and a high amplitude, which is used to generate an arc discharge in the simulation experiment.

[0031] The pressure detection probes can be arranged at different positions inside the transformer tank, which are used to detect the change of the pressure waveform generated during the arc discharge in real time and obtain the pressure distribution data at multiple points inside the tank. The pressure detection probes are composed of highly sensitive pressure sensors. The pressure sensors are fixed inside the tank through a special interface and can adjust their installation positions according to the test requirements to monitor the pressure changes in different areas. The signal output end of the pressure sensor is connected to the data acquisition module, and after filtering and signal amplification, it is transmitted to the oscilloscope and the storage device. By monitoring the pressure signal in real time, the pressure waveform data caused by the arc discharge can be accurately obtained, providing an important basis for studying the propagation characteristics of the pressure wave.

[0032] In the above embodiments, the intrinsic breakdown test method is used to simulate arc discharge. The intrinsic breakdown directly reflects the voltage withstand ability of the insulating material in the sample, can simulate the voltage breakdown process under actual operating conditions, and thus more realistically evaluate the performance of the insulating material. In addition, since the intrinsic breakdown does not require the use of an arc ignition wire for initiation, it is applicable to the testing of various types of insulating materials and their samples. The intrinsic breakdown test can evaluate the voltage withstand characteristics of the insulating material under different voltage conditions, determine its breakdown voltage, strength, and voltage withstand ability, thereby providing a scientific basis for evaluating the safety and reliability of the insulating material. Compared with the arc ignition wire method, the application of the intrinsic breakdown test in the arc test system has higher real reducibility and wide applicability, and can more comprehensively evaluate the comprehensive performance of the insulating material, which is a more real and reliable test method.

[0033] Further, the electrodes include a high-voltage electrode and a low-voltage electrode, which are respectively connected to the high-voltage side two-phase bushings of the transformer under test.

[0034] Specifically, the high-voltage side A, B, and C three-phase bushings are provided on the oil tank, and any two phases can be respectively used to connect the high-voltage electrode and the low-voltage electrode. The high-voltage side bushings are made of high-strength insulating materials and are fixed on the oil tank wall through flanges and sealing gaskets, which can effectively isolate the high-voltage part from the external environment and ensure the safety and stability of the test process. The electrodes are connected to the original high-voltage bushings of the transformer through conductive connectors, with electrical insulation protection functions, effectively avoiding the occurrence of leakage during the test.

[0035] Further, the test system further includes:

[0036] An electrode adjusting device, which is arranged between the high-voltage side two-phase bushings of the transformer under test and includes an adjusting rod and a limit bolt;

[0037] Among them, the adjusting rod is used to adjust the distance between the high-voltage electrode and the low-voltage electrode to meet the requirements of different test conditions.

[0038] Specifically, the adjusting rod can accurately adjust the distance between the high-voltage electrode and the low-voltage electrode by rotation to meet the requirements of different test conditions. The electrode is connected to the adjusting rod by bolts. The adjusting device is designed as a detachable structure, which is convenient for the replacement and maintenance of the test electrodes.

[0039] Further, the electrodes adopt a tip-tip structure, a tip-plate structure, or a plate-plate structure.

[0040] Specifically, the electrode material is made of copper-tungsten alloy with good electrical conductivity, and different forms of electrode structures can be adopted according to different test conditions and working conditions requirements.

[0041] Further, the pulse power supply 102 includes a Marx impulse voltage generator 1021, including:

[0042] A voltage regulator, a silicon stack, a current-limiting resistor, a capacitor bank, and a trigger gap;

[0043] Among them, the output terminal of the voltage regulator is sequentially connected to the silicon stack, the current-limiting resistor, the capacitor bank, and the trigger gap.

[0044] Specifically, the high-voltage end of the capacitor bank is connected to the high-voltage electrode. The main function of the pulse power supply is to generate a pulse voltage, simulate arc discharge in liquid media such as water, and adjust the amplitude of the pulse voltage by adjusting the settings of the voltage regulator. The output terminal of the voltage regulator is sequentially connected to the silicon stack, the current-limiting resistor, the capacitor bank, and the trigger gap, and the high-voltage end of the capacitor bank is connected to the high-voltage electrode, which can generate a pulse voltage of up to 500 kV.

[0045] In the above embodiment, by adjusting the output voltage of the voltage regulator to change the charging voltage of each capacitor, the amplitude of the pulse voltage is adjusted. This system can more accurately simulate the arc discharge phenomenon occurring inside the actual transformer oil tank, making the test results more reliable and valuable for reference.

[0046] Furthermore, the pulse power supply 102 further includes:

[0047] A voltage divider 1022, with both ends connected to two electrodes respectively, for measuring the discharge voltage between the electrodes;

[0048] A Rogowski coil set 1023, arranged on the low-voltage output line, for measuring the discharge current signal between the electrodes and generating a proportional voltage signal.

[0049] Specifically, the pulse power supply system is equipped with a voltage divider and a Rogowski coil. The voltage divider is used to divide and measure the discharge voltage between the electrodes, with the high-voltage end connected to the high-voltage electrode and the low-voltage end connected to the low-voltage electrode; the Rogowski coil is sleeved on the low-voltage output line, for collecting the discharge current signal between the electrodes and generating a proportional voltage signal to ensure the accuracy and integrity of data collection. The pressure detection probe combines the voltage divider and the Rogowski coil, and can synchronously collect voltage, current, and pressure data, providing comprehensive support for the analysis of arc discharge behavior and the pressure propagation characteristics inside the oil tank.

[0050] Furthermore, the test system further includes:

[0051] A first oscilloscope 106, for displaying the signals detected by the pressure detection probe.

[0052] Specifically, the pressure detection probe sends the detected signals to the first oscilloscope.

[0053] Furthermore, the test system further includes:

[0054] A second oscilloscope 107, for displaying the signals measured by the voltage divider and the Rogowski coil set.

[0055] Specifically, the voltage divider and the Rogowski coil set send the measured signals to the second oscilloscope.

[0056] The test system provided by the above embodiments provides a pulsed voltage to the electrodes through a pulsed power supply to generate pulsed arc discharge between the two electrodes, which can truly simulate the arc discharge phenomenon under actual operating conditions, truly restore the transient pressure change, and significantly improve the accuracy and reliability of test data; by detecting the pressure wave intensity generated by the arc discharge through the pressure detection probes arranged at different positions in the tank of the transformer under test, the mechanical strength of the transformer tank can be evaluated more comprehensively, and the possible weak points of the tank under different working conditions can be revealed.

[0057] The test system provided by some of the above embodiments adopts an adjustable pulsed power supply and various electrode forms, which can flexibly adjust the test conditions, realize the simulation of various working conditions, further expand the applicable range of the test method, and provide a reliable basis for optimizing the explosion-proof design of the transformer.

[0058] Figure 2 An exemplary flowchart of a method for testing the mechanical strength of a transformer tank under arc discharge simulation according to an embodiment of the present invention is shown.

[0059] As Figure 2 shown, the method is applied to the test system for the mechanical strength of a transformer tank under arc discharge simulation provided by the above respective embodiments, and includes:

[0060] Step S201: Inject a liquid medium into the transformer tank under test and install the electrodes.

[0061] Step S202: Supply power to the electrodes using a pulsed power supply to simulate an arc discharge fault in the transformer.

[0062] Step S203: Collect and record the pressure wave intensity generated by the arc discharge detected by the pressure detection probes.

[0063] Step S204: Check the condition of the transformer tank under test after the discharge, and judge the structural strength of the transformer tank under test according to the inspection results.

[0064] Further, the inspection results include whether the transformer tank under test is ruptured and the range of flying debris after the rupture of the transformer tank under test. Judging the structural strength of the transformer tank under test according to the inspection results includes:

[0065] If the transformer tank is not ruptured, or although it is ruptured but all the flying debris is contained within the defined area, it can be determined that the structural strength of the transformer tank under test meets the requirements;

[0066] If the transformer oil tank ruptures and the flying debris exceeds the defined area, it is determined that the structural strength of the tested transformer oil tank does not meet the requirements.

[0067] Specifically, inject a liquid medium such as test water into the tested transformer oil tank and install the electrodes, ensuring the sealing of the oil tank and the integrity of the connection of the test device. Use the pulsed power supply system to supply power to the test electrodes to simulate the occurrence of arc discharge inside the transformer under actual conditions. During the discharge process, measure the discharge voltage between the electrodes through a voltage divider, collect the discharge current signal through a Rogowski coil, and set the pressure monitoring probe near the oil tank wall to record the pressure change generated during the internal discharge of the transformer.

[0068] Judge the structural strength of the transformer oil tank according to the inspection situation of the oil tank: If the transformer oil tank does not rupture at the specified arc initiation position and specified pressure, or although it ruptures but all the flying debris is contained within the defined area, it can be determined that the design of the transformer oil tank meets the requirements; if the transformer oil tank ruptures and the flying debris exceeds the defined area, necessary improvement measures should be taken according to the evaluation results.

[0069] The testing method provided by the above embodiments can provide a pulsed voltage to the electrodes through a pulsed power supply to generate a pulsed arc discharge between the two electrodes, which can truly simulate the arc discharge phenomenon under actual operating conditions, truly restore the transient pressure change, and significantly improve the accuracy and reliability of the test data; by detecting the pressure wave intensity generated by the arc discharge through the pressure detection probes set at different positions in the tested transformer oil tank, the mechanical strength of the transformer oil tank can be evaluated more comprehensively, and the possible weak points of the oil tank under different working conditions can be revealed. This testing method has accurate data, simple operation, can truly restore the actual working conditions, and has broad application prospects and important technical value.

[0070] The testing method provided by some of the above embodiments adopts an adjustable pulsed power supply and various electrode forms, which can flexibly adjust the test conditions, realize the simulation of various working conditions, further expand the applicable range of the test method, and provide a reliable basis for optimizing the explosion-proof design of the transformer.

[0071] The present invention has been described by referring to a few embodiments. However, as is well known to those skilled in the art, other embodiments equivalent to those disclosed above of the present invention equally fall within the scope of the present invention as defined by the appended patent claims.

[0072] Generally, all terms used in the claims are construed according to their ordinary meaning in the technical field, unless otherwise expressly defined therein. All references to "a / the [device, component, etc.]" are to be construed openly as at least one instance of the device, component, etc., unless otherwise expressly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed, unless expressly stated.

[0073] Those skilled in the art will appreciate that embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

[0074] The present invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and / or block of the flowchart illustrations and / or block diagrams, and combinations of flows and / or blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing device, create means for implementing the functions specified in Figure 1 one or more of the flows Figure 1 or blocks.

[0075] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means that implement the functions specified in Figure 1 one or more of the flows Figure 1 or blocks.

[0076] These computer program instructions may also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are performed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one or more of the flows Figure 1 or blocks.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: it is still possible to modify the specific implementation manners of the present invention or make equivalent replacements, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A test system for the mechanical strength of a transformer oil tank under arc discharge simulation, characterized in that, The test system includes: a test transformer oil tank for containing a liquid medium; a pulse power supply for generating a pulse voltage to supply power to the electrodes; electrodes disposed in the test transformer oil tank and connected to the pulse power supply, for introducing a pulse voltage to generate a pulsed arc discharge between the two electrodes, so as to simulate an arc discharge fault occurring in the transformer; pressure detection probes disposed at different positions in the test transformer oil tank for detecting the intensity of the pressure wave generated by the arc discharge; conductive connectors for connecting the electrodes to the test transformer oil tank.

2. The test system according to claim 1, wherein The electrodes include a high-voltage electrode and a low-voltage electrode, which are respectively connected to the two-phase bushings on the high-voltage side of the test transformer oil tank.

3. The test system according to claim 2, characterized in that, The test system further includes: an electrode adjusting device disposed between the two-phase bushings on the high-voltage side of the test transformer oil tank, including an adjusting rod and a limit bolt; wherein, the adjusting rod is used to adjust the distance between the high-voltage electrode and the low-voltage electrode to meet the requirements of different test conditions.

4. The test system according to claim 1, characterized in that The electrodes adopt a tip-tip structure, a tip-plate structure or a plate-plate structure.

5. The test system according to claim 1, wherein The pulse power supply includes a Marx impulse voltage generator, including: a voltage regulator, a silicon stack, a current-limiting resistor, a capacitor bank and a trigger gap; wherein, the output end of the voltage regulator is sequentially connected to the silicon stack, the current-limiting resistor, the capacitor bank and the trigger gap.

6. The test system according to claim 1, wherein The pulse power supply further includes: a voltage divider with both ends respectively connected to the two electrodes for measuring the discharge voltage between the electrodes; a Rogowski coil set disposed on the low-voltage output line for measuring the discharge current signal between the electrodes and generating a proportional voltage signal.

7. The test system according to claim 1, wherein The test system further includes: a first oscilloscope for displaying the signals detected by the pressure detection probes.

8. The test system according to claim 6, characterized in that, The test system further includes: a second oscilloscope for displaying the signals measured by the voltage divider and the Rogowski coil set.

9. A test method for the mechanical strength of a transformer oil tank under arc discharge simulation, characterized in that, For a test system for the mechanical strength of a transformer oil tank under the arc discharge simulation as described in any one of claims 1-8, the test method includes: Injecting a liquid medium into the test transformer oil tank and installing the electrodes; Using the pulse power supply to supply power to the electrodes to simulate an arc discharge fault occurring in the transformer; Collecting and recording the intensity of the pressure wave generated by the arc discharge detected by the pressure detection probes; Inspecting the situation of the test transformer oil tank after the discharge and judging the structural strength of the test transformer oil tank according to the inspection situation.

10. The test method according to claim 9, characterized in that, The inspection situation includes whether the test transformer oil tank is ruptured and the range of the flying debris after the test transformer oil tank is ruptured. Judging the structural strength of the test transformer oil tank according to the inspection situation includes: If the transformer oil tank is not ruptured, or although it is ruptured but all the flying debris is contained within the defined area, it can be determined that the structural strength of the test transformer oil tank meets the requirements; If the transformer oil tank is ruptured and the flying debris exceeds the defined area, it is determined that the structural strength of the test transformer oil tank does not meet the requirements.

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