Transformer insulation cushion block anti-short circuit electromagnetic force impact evaluation method and system

Abstract

The invention discloses an anti-short-circuit electromagnetic force impact evaluation method and system for a transformer insulation cushion block, and the method comprises the steps: obtaining a to-be-tested transformer insulation cushion block, and testing a first performance parameter of the to-be-tested transformer insulation cushion block; configuring short-circuit electromagnetic force impact test conditions of the to-be-tested transformer insulation cushion block; wherein the transformer insulation cushion block to be tested corresponds to a plurality of short-circuit electromagnetic force impact test conditions; each short-circuit electromagnetic force impact test condition corresponds to an electromagnetic impact force amplitude, an electromagnetic impact force time interval and an electromagnetic impact force frequency; according to the short-circuit electromagnetic force impact test condition, performing a simulation short-circuit electromagnetic force impact test on the to-be-tested transformer insulation cushion block, testing a second performance parameter, and comparing the second performance parameter with the first performance parameter to obtain a total comparison result; and determining the anti-short-circuit electromagnetic force capability of the to-be-tested transformer insulation cushion block according to the total comparison result, and by implementing the method, the anti-short-circuit electromagnetic force impact evaluation cost of the transformer insulation cushion block is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of transformer short-circuit resistance, and in particular to a method and system for evaluating the short-circuit electromagnetic force impact resistance of a transformer insulating pad. Background Art

[0002] In the power system, the transformer is one of the key electrical equipment, and its reliability is directly related to the safe operation of the entire system. When the transformer winding is subjected to the dynamic short-circuit electromagnetic force impact, axial and auxiliary instability and tangential twisting may occur, causing the insulation pad to be misplaced, fall off, and the support bar to fall, and in severe cases, the insulation layer is damaged. The result of the dynamic short-circuit electromagnetic force impact will change the insulation distance between wires with different potentials, and voltage breakdown may occur, causing electrical short circuits between turns, layers, or windings.

[0003] At present, the short-circuit withstand capacity of transformer insulation spacers is mainly evaluated by directly conducting short-circuit current impulse tests on the transformer body. The short-circuit current impulse test on the transformer body is used to test the short-circuit withstand capacity of the transformer insulation spacers. However, the short-circuit current impulse test has extremely high requirements on the test conditions and test costs, and cannot be promoted and applied on a large scale. Summary of the invention

[0004] The embodiment of the present invention provides a method for evaluating the resistance of transformer insulating spacers to short-circuit electromagnetic force impact, which can effectively solve the problem of extremely high requirements on test conditions and test costs in the short-circuit current impact test in the prior art.

[0005] An embodiment of the present invention provides a method for evaluating the resistance of a transformer insulating spacer to short-circuit electromagnetic force impact, comprising:

[0006] Obtaining an insulating spacer of the transformer to be tested, and testing a first performance parameter of the insulating spacer of the transformer to be tested, which is used to represent initial performance;

[0007] Configure the short-circuit electromagnetic force impact test conditions of the transformer insulation pad to be tested; wherein the transformer insulation pad to be tested corresponds to a plurality of short-circuit electromagnetic force impact test conditions; each short-circuit electromagnetic force impact test condition corresponds to an electromagnetic impact force amplitude, an electromagnetic impact force time interval and an electromagnetic impact force number;

[0008] Performing a simulated short-circuit electromagnetic force impact test on the insulation pad of the transformer to be tested according to the short-circuit electromagnetic force impact test conditions corresponding to the insulation pad of the transformer to be tested;

[0009] The second performance parameter of the insulating spacer of the transformer to be tested which has undergone a simulated short-circuit electromagnetic force impact test is tested, and the second performance parameter of the insulating spacer of the transformer to be tested is compared with the first performance parameter to obtain a total comparison result for indicating a performance change; and the short-circuit electromagnetic force resistance capability of the insulating spacer of the transformer to be tested is determined based on the total comparison result.

[0010] Further, when the first performance parameter is a mechanical performance parameter, the determination of the short-circuit electromagnetic force resistance capability of the transformer insulation pad to be tested includes:

[0011] Compare the first mechanical property parameter used to represent the insulating spacer of the transformer to be tested before the simulated short-circuit electromagnetic force impact test with the second mechanical property parameter used to represent the insulating spacer after the simulated short-circuit electromagnetic force impact test, and obtain a first comparison result used to represent the change of the mechanical property of the insulating spacer of the transformer to be tested in the total comparison result;

[0012] The short-circuit resistance capability of the insulating spacer of the transformer to be tested is determined according to the first comparison result.

[0013] Further, when the first performance parameter is an appearance structure parameter, the determination of the short-circuit electromagnetic force resistance capability of the transformer insulation pad to be tested includes:

[0014] Compare the first appearance structure parameter used to represent the insulating spacer of the transformer to be tested before the simulated short-circuit electromagnetic force impact test with the second appearance structure parameter used to represent the insulating spacer of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, and obtain a second comparison result used to represent the appearance structure change of the insulating spacer of the transformer to be tested in the total comparison result;

[0015] The short-circuit electromagnetic force resistance capability of the insulating spacer of the transformer to be tested is determined according to the second comparison result.

[0016] Furthermore, the first mechanical performance parameter includes: a first pressure waveform and a first pressure value; the second mechanical performance parameter includes: a second pressure waveform and a second pressure value;

[0017] The first mechanical property parameter used to represent the insulating spacer of the transformer to be tested before the simulated short-circuit electromagnetic force impact test is compared with the second mechanical property parameter used to represent the insulating spacer of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, including:

[0018] The second pressure waveform and the second pressure value of the transformer insulation pad to be tested after the simulated short-circuit electromagnetic force impact test are respectively compared with the initial first pressure waveform and the first pressure value of the transformer insulation pad to be tested.

[0019] Further, the first appearance structure parameter includes: a first deformation amount, a first thickness and a first area; the second appearance structure parameter includes: a second deformation amount, a second thickness and a second area;

[0020] Comparing the first appearance structure parameter used to represent the insulation pad of the transformer to be tested before the simulated short-circuit electromagnetic force impact test with the second appearance structure parameter used to represent the insulation pad of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, including:

[0021] The first deformation amount, the first thickness and the first area of ​​the insulating pad of the transformer to be tested before the simulated short-circuit electromagnetic force impact test are compared with the second deformation amount, the second thickness and the second area after the simulated short-circuit electromagnetic force impact test.

[0022] Further, the short-circuit electromagnetic force impact test condition includes: a first test condition for representing a static electromagnetic impact force test, a second test condition for representing a dynamic electromagnetic impact force test, and a third test condition for representing a static electromagnetic impact force test after the dynamic electromagnetic impact force test;

[0023] The electromagnetic impact force amplitude corresponding to the first test condition is consistent with the electromagnetic impact force amplitude corresponding to the third test condition;

[0024] The number of electromagnetic impact forces corresponding to the first test condition is consistent with the number of electromagnetic impact forces corresponding to the third test condition.

[0025] Furthermore, the electromagnetic impact force corresponding to the second test condition presents periodic changes;

[0026] The calculation of the electromagnetic impact force corresponding to the second test condition includes:

[0027] The electromagnetic impact force corresponding to the second test condition is calculated according to the electromagnetic impact force amplitude corresponding to the second test condition, the preset electromagnetic impact force frequency and the preset period interval.

[0028] Furthermore, the method further comprises: before carrying out a simulated short-circuit electromagnetic force impact test on the insulating pad of the transformer to be tested, performing an oil immersion treatment.

[0029] Furthermore, the insulating spacer of the transformer to be tested is composed of a plurality of insulating paperboards of uniform thickness stacked together.

[0030] As an improvement of the above solution, another embodiment of the present invention provides a transformer insulation pad resistance to short-circuit electromagnetic force impact assessment system, including:

[0031] A pad parameter acquisition module, used to acquire the insulating pad of the transformer to be tested, and test a first performance parameter of the insulating pad of the transformer to be tested, which is used to represent the initial performance;

[0032] A condition configuration module is used to configure the short-circuit electromagnetic force impact test conditions of the transformer insulation pad to be tested; wherein the transformer insulation pad to be tested corresponds to a plurality of short-circuit electromagnetic force impact test conditions; each short-circuit electromagnetic force impact test condition corresponds to an electromagnetic impact force amplitude, an electromagnetic impact force time interval and an electromagnetic impact force number;

[0033] A simulation test module, used for performing a simulated short-circuit electromagnetic force impact test on the insulation pad of the transformer to be tested according to the short-circuit electromagnetic force impact test conditions corresponding to the insulation pad of the transformer to be tested;

[0034] The insulating pad evaluation module is used to test the second performance parameter of the insulating pad of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, and compare the second performance parameter of the insulating pad of the transformer to be tested with the first performance parameter to obtain a total comparison result used to represent the performance change; and determine the short-circuit electromagnetic force resistance capability of the insulating pad of the transformer to be tested based on the total comparison result.

[0035] By implementing the present invention, at least the following beneficial effects are achieved:

[0036] The present invention provides a method for evaluating the resistance of transformer insulating pads to short-circuit electromagnetic force impact. The method can obtain the transformer insulating pad to be tested, and test the first performance parameter of the transformer insulating pad to be tested for indicating the initial performance; configure the short-circuit electromagnetic force impact test conditions of the transformer insulating pad to be tested; wherein the transformer insulating pad to be tested corresponds to a plurality of short-circuit electromagnetic force impact test conditions; each short-circuit electromagnetic force impact test condition corresponds to an electromagnetic impact force amplitude, an electromagnetic impact force time interval and an electromagnetic impact force number; perform a simulated short-circuit electromagnetic force impact test on the transformer insulating pad to be tested according to the short-circuit electromagnetic force impact test conditions corresponding to the transformer insulating pad to be tested; test the second performance parameter of the transformer insulating pad to be tested after the simulated short-circuit electromagnetic force impact test, and compare the second performance parameter of the transformer insulating pad to be tested with the first performance parameter to obtain a total comparison result for indicating the performance change; and determine the short-circuit electromagnetic force resistance capability of the transformer insulating pad to be tested according to the total comparison result. By performing a simulated short-circuit electromagnetic force impact test on the transformer insulating pad, instead of directly performing an impact test on the transformer body, the configured short-circuit electromagnetic force impact test conditions can simulate the working environment of the transformer insulating pad under normal operation, and the simulated short-circuit electromagnetic force impact test is performed on the transformer insulating pad to be tested under the short-circuit electromagnetic force impact test conditions. By comparing the first performance parameter and the second performance parameter, the specific change in the performance of the insulating pad after being subjected to the short-circuit electromagnetic force impact can be obtained, so as to determine the short-circuit electromagnetic force resistance of the transformer insulating pad to be tested according to the first comparison result. The test conditions are not demanding, the test cost is low, and large-scale promotion and application can be carried out. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a flow chart of a method for evaluating the resistance of transformer insulation pads to short-circuit electromagnetic force impact provided by one embodiment of the present invention;

[0038] Figure 2It is a schematic diagram of a transformer insulation pad to be tested in a method for evaluating the resistance of transformer insulation pad to short-circuit electromagnetic force impact provided by an embodiment of the present invention;

[0039] Figure 3 It is a schematic diagram of a pressure waveform of a method for evaluating the resistance of a transformer insulating spacer to short-circuit electromagnetic force impact provided by an embodiment of the present invention;

[0040] Figure 4 It is a schematic diagram of a short-circuit current waveform of a method for evaluating the resistance of a transformer insulating spacer to short-circuit electromagnetic force impact provided by an embodiment of the present invention;

[0041] Figure 5 It is a structural schematic diagram of a transformer insulation pad resistance to short-circuit electromagnetic force impact assessment system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0044] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0045] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0046] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0047] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0048] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0049] See also Figure 1 , is a flow chart of a method for evaluating the short-circuit electromagnetic force impact resistance of a transformer insulating spacer provided by an embodiment of the present invention, comprising:

[0050] S1. Obtain an insulating spacer block of a transformer to be tested, and test a first performance parameter of the insulating spacer block of the transformer to be tested, which is used to represent initial performance;

[0051] S2, configuring the short-circuit electromagnetic force impact test conditions of the insulation pad of the transformer to be tested; wherein the insulation pad of the transformer to be tested corresponds to a plurality of short-circuit electromagnetic force impact test conditions; each short-circuit electromagnetic force impact test condition corresponds to an electromagnetic impact force amplitude, an electromagnetic impact force time interval and an electromagnetic impact force number;

[0052] S3, performing a simulated short-circuit electromagnetic force impact test on the insulation pad of the transformer to be tested according to the short-circuit electromagnetic force impact test conditions corresponding to the insulation pad of the transformer to be tested;

[0053] S4. Test the second performance parameter of the insulating spacer of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, and compare the second performance parameter of the insulating spacer of the transformer to be tested with the first performance parameter to obtain a total comparison result for indicating the performance change; determine the short-circuit electromagnetic force resistance capability of the insulating spacer of the transformer to be tested according to the total comparison result.

[0054] Specifically, the initial performance of the transformer insulation pad to be tested should be tested before testing to obtain the first performance parameter, which is convenient for comparison with subsequent test results. The short-circuit electromagnetic force impact test condition simulates the environmental conditions of the transformer insulation pad in the working state by configuring different electromagnetic impact force amplitudes, electromagnetic impact force time intervals, and electromagnetic impact force times.

[0055] In a preferred embodiment of the present invention, first obtain the insulation pad of the transformer to be tested, and test the first performance parameter of the insulation pad of the transformer to be tested for indicating the initial performance, and then configure the short-circuit electromagnetic force impact test conditions of the insulation pad of the transformer to be tested; wherein, the insulation pad of the transformer to be tested corresponds to several short-circuit electromagnetic force impact test conditions; each short-circuit electromagnetic force impact test condition corresponds to an electromagnetic impact force amplitude, an electromagnetic impact force time interval and an electromagnetic impact force number; then perform a simulated short-circuit electromagnetic force impact test on the insulation pad of the transformer to be tested according to the short-circuit electromagnetic force impact test conditions corresponding to the insulation pad of the transformer to be tested; then test the second performance parameter of the insulation pad of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, and compare the second performance parameter of the insulation pad of the transformer to be tested with the first performance parameter to obtain a total comparison result for indicating the performance change, and finally determine the short-circuit electromagnetic force resistance of the insulation pad of the transformer to be tested according to the total comparison result. By comparing the first performance parameter and the second performance parameter, the performance change of the insulation pad of the transformer to be tested after the simulated short-circuit electromagnetic force impact test can be understood, which is helpful to evaluate its short-circuit electromagnetic force resistance. If it is found that the performance has declined significantly, the design of the insulating spacer can be optimized to improve its ability to resist short-circuit electromagnetic forces. Ensuring that the transformer insulating spacer has good ability to resist short-circuit electromagnetic forces can reduce the risk of accidents caused by short circuits and improve the reliability and stability of the entire transformer system.

[0056] Preferably, when the first performance parameter is a mechanical performance parameter, determining the short-circuit electromagnetic force resistance capability of the transformer insulation pad to be tested includes:

[0057] Compare the first mechanical property parameter used to represent the insulating spacer of the transformer to be tested before the simulated short-circuit electromagnetic force impact test with the second mechanical property parameter used to represent the insulating spacer after the simulated short-circuit electromagnetic force impact test, and obtain a first comparison result used to represent the change of the mechanical property of the insulating spacer of the transformer to be tested in the total comparison result;

[0058] The short-circuit resistance capability of the insulating spacer of the transformer to be tested is determined according to the first comparison result.

[0059] Preferably, when the first performance parameter is an appearance structure parameter, determining the short-circuit electromagnetic force resistance capability of the transformer insulation pad to be tested includes:

[0060] Compare the first appearance structure parameter used to represent the insulating spacer of the transformer to be tested before the simulated short-circuit electromagnetic force impact test with the second appearance structure parameter used to represent the insulating spacer of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, and obtain a second comparison result used to represent the appearance structure change of the insulating spacer of the transformer to be tested in the total comparison result;

[0061] The short-circuit electromagnetic force resistance capability of the insulating spacer of the transformer to be tested is determined according to the second comparison result.

[0062] In a preferred embodiment of the present invention, the mechanical properties of the insulating pad of the transformer to be tested may change after the simulated short-circuit electromagnetic force impact test. Therefore, in order to evaluate the accuracy of the short-circuit electromagnetic force resistance of the insulating pad of the transformer to be tested, it is also necessary to record the first mechanical performance parameter used to represent the insulating pad of the transformer to be tested before the simulated short-circuit electromagnetic force impact test, and record the second mechanical performance parameter used to represent the second mechanical performance parameter after the simulated short-circuit electromagnetic force impact test, and then compare the first mechanical performance parameter with the second mechanical performance parameter to obtain the first comparison result used to represent the change in the mechanical properties of the insulating pad of the transformer to be tested in the total comparison result, and finally determine the short-circuit electromagnetic force resistance of the insulating pad of the transformer to be tested according to the first comparison result. By comparing the changes in the mechanical performance parameters, the mechanical performance changes of the insulating pad under the short-circuit electromagnetic force impact can be quickly identified, thereby improving the test efficiency and improving the efficiency of evaluating the short-circuit electromagnetic force resistance of the insulating pad of the transformer to be tested.

[0063] In a preferred embodiment of the present invention, the insulating pad of the transformer to be tested may be deformed after being subjected to a simulated short-circuit electromagnetic force impact test. Therefore, in order to evaluate the accuracy of the short-circuit electromagnetic force resistance capability of the insulating pad of the transformer to be tested, it is also necessary to record the first appearance structural parameter used to represent the insulating pad of the transformer to be tested before the simulated short-circuit electromagnetic force impact test, and record the second appearance structural parameter used to represent the appearance structural parameter after the simulated short-circuit electromagnetic force impact test, and then compare the first appearance structural parameter with the second appearance structural parameter to obtain a second comparison result in the total comparison result to represent the appearance structural change of the insulating pad of the transformer to be tested, and finally determine the short-circuit electromagnetic force resistance capability of the insulating pad of the transformer to be tested according to the second comparison result. By comparing the changes in the appearance structural parameters, the structural changes of the insulating pad under the short-circuit electromagnetic force impact can be quickly identified, thereby improving the test efficiency and improving the efficiency of evaluating the short-circuit electromagnetic force resistance capability of the insulating pad of the transformer to be tested.

[0064] Specifically, the first mechanical performance parameter includes: a first pressure waveform and a first pressure value; the second mechanical performance parameter includes: a second pressure waveform and a second pressure value;

[0065] The first mechanical property parameter used to represent the insulating spacer of the transformer to be tested before the simulated short-circuit electromagnetic force impact test is compared with the second mechanical property parameter used to represent the insulating spacer of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, including:

[0066] The second pressure waveform and the second pressure value of the transformer insulation pad to be tested after the simulated short-circuit electromagnetic force impact test are respectively compared with the initial first pressure waveform and the first pressure value of the transformer insulation pad to be tested.

[0067] In a preferred embodiment of the present invention, the first pressure value represents the pressure value of the insulating pad during the stress process when a small pressure is applied to the insulating pad of the transformer to be tested before the simulation test; the first pressure waveform represents the entire process of the insulating pad bearing pressure from the beginning of application to the final stabilization or peak value before the simulation test. The first performance parameter can ensure that the insulating pad is in a normal state before the simulation test, and the evaluation result is not inaccurate due to external factors such as incomplete or unqualified materials. The second pressure value represents the pressure value borne during the simulation test; the second pressure waveform represents the entire process of the insulating pad being subjected to a large electromagnetic impact force from the beginning to the final stabilization or peak value during the simulation test, and this second pressure waveform can reveal the reaction characteristics of the insulating pad when it is impacted. Comparing the first pressure value and the second pressure value can intuitively understand the change in the maximum pressure that the insulating pad can withstand before and after being impacted by the short-circuit electromagnetic force. This helps to determine whether the insulating pad has performance degradation during the test or whether it can maintain its original pressure bearing capacity. Comparing the first pressure waveform with the second pressure waveform can provide a more detailed analysis of the dynamic response of the insulating spacer during the impact process, including its deformation rate and recovery when subjected to force. This information is crucial for predicting the performance of the insulating spacer in actual operation.

[0068] Preferably, the first appearance structure parameter includes: a first deformation amount, a first thickness and a first area; the second appearance structure parameter includes: a second deformation amount, a second thickness and a second area;

[0069] Comparing the first appearance structure parameter used to represent the insulation pad of the transformer to be tested before the simulated short-circuit electromagnetic force impact test with the second appearance structure parameter used to represent the insulation pad of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, including:

[0070] The first deformation amount, the first thickness and the first area of ​​the insulating pad of the transformer to be tested before the simulated short-circuit electromagnetic force impact test are compared with the second deformation amount, the second thickness and the second area after the simulated short-circuit electromagnetic force impact test.

[0071] In a preferred embodiment of the present invention, the first deformation refers to the deformation of the insulating pad before the simulation test; the first thickness refers to the thickness of the insulating pad before the simulation test; the first area refers to the floor area of ​​the insulating pad before the simulation test. The second deformation refers to the deformation of the insulating pad after the simulation test; the second thickness refers to the thickness of the insulating pad after the simulation test; the second area refers to the floor area of ​​the insulating pad after the simulation test. The first deformation, first thickness and first area of ​​the insulating pad of the transformer to be tested before the simulated short-circuit electromagnetic force impact test are compared with the second deformation, second thickness and second area after the simulated short-circuit electromagnetic force impact test, respectively, to obtain a second comparison result for indicating the change in appearance structure. By comparing the changes in deformation, thickness and area, the structural changes of the insulating pad under the short-circuit electromagnetic force impact can be more accurately evaluated.

[0072] Schematically, the short-circuit electromagnetic force impact test condition includes: a first test condition for representing a static electromagnetic impact force test, a second test condition for representing a dynamic electromagnetic impact force test, and a third test condition for representing a static electromagnetic impact force test after the dynamic electromagnetic impact force test.

[0073] Specifically, the electromagnetic impact force amplitude corresponding to the first test condition is consistent with the electromagnetic impact force amplitude corresponding to the third test condition.

[0074] Specifically, the number of electromagnetic impact forces corresponding to the first test condition is consistent with the number of electromagnetic impact forces corresponding to the third test condition.

[0075] Specifically, the electromagnetic impact force corresponding to the second test condition presents periodic changes;

[0076] The calculation of the electromagnetic impact force corresponding to the second test condition includes:

[0077] The electromagnetic impact force corresponding to the second test condition is calculated according to the electromagnetic impact force amplitude corresponding to the second test condition, the preset electromagnetic impact force frequency and the preset period interval.

[0078] In a preferred embodiment of the present invention, the configuration of the short-circuit electromagnetic force impact test condition includes three stages: first, the configuration of the first test condition for representing the static electromagnetic impact force test, second, the configuration of the second test condition for representing the dynamic electromagnetic impact force test; and third, the configuration of the third test condition for representing the static electromagnetic impact force test after the dynamic electromagnetic impact force test. The electromagnetic impact force amplitude corresponding to the first test condition is consistent with the electromagnetic impact force amplitude corresponding to the third test condition, and the number of electromagnetic impact forces corresponding to the first test condition is consistent with the number of electromagnetic impact forces corresponding to the third test condition, that is, the electromagnetic impact forces corresponding to the first test condition and the third test condition are consistent in magnitude and number of impacts. Under the first test condition, the insulating pad is first subjected to the applied electromagnetic impact force, and then after the second test condition test, under the third test condition, in order to eliminate the cumulative effect of the force, the electromagnetic impact force amplitude and the number of electromagnetic impact forces corresponding to the third test condition are consistent, so as to obtain a more accurate insulating pad comparison result. The electromagnetic impact force corresponding to the second test condition presents a periodic change, simulates the electric force generated by the equivalent short-circuit current, and is applied to the insulating pad to achieve the effect of the transformer insulating pad being impacted by dynamic force.

[0079] Preferably, before the insulation pad of the transformer to be tested is subjected to a simulated short-circuit electromagnetic force impact test, it is immersed in oil.

[0080] Preferably, the insulating spacer block of the transformer to be tested is composed of a plurality of insulating paperboards stacked together with uniform thickness.

[0081] In a preferred embodiment of the present invention, an insulating paperboard with a thickness of 1.5 mm or 2 mm is selected. Figure 2 As shown, the test samples are cut into several certain sizes, such as 30×30mm, and then the test samples are stacked in multiple layers (stacked thickness is 10-15mm) for pressure drying, and the pressure is maintained for 5 minutes. Then, the test samples are dried in kerosene gas phase under pressure, and the drying temperature is 110°C, the continuous drying time is 36 hours, and the vacuum degree is 30 Pa. After drying out of the oven, the insulating pad is pressurized again at a pressure of 35kg / cm2, and then the test pad sample is placed in a container filled with transformer oil for oil immersion treatment, and left to stand for 24 hours to obtain the transformer insulation pad to be tested, and then the transformer insulation pad to be tested is placed in a fatigue testing machine that can load an adjustable pressure waveform.

[0082] In a preferred embodiment of the present invention, a steady-state force of 2MPa, i.e., Fs=1.8kN, is applied to the insulating pad of the transformer to be tested according to the first test condition (electromagnetic impact force amplitude 2MPa, electromagnetic impact force time interval 1 minute, electromagnetic impact force number 1 time), for 1 minute, and the deformation, thickness, area, pressure value and pressure waveform of the insulating pad after the first test condition test are recorded. Then, a dynamic force of Fm / 2+Fm / 2*sin(2*π*f*t) is applied to the insulating pad of the transformer to be tested according to the second test condition (electromagnetic impact force amplitude Fm, electromagnetic impact force time interval 20ms, electromagnetic impact force number 9 times), where Fm is the dynamic force peak value, f is the dynamic force waveform frequency, and t is time. The dynamic electromagnetic impact force parameters applied to the insulating pad of the transformer to be tested are shown in Table 1. The test lasts for 9 cycles, and the deformation, thickness, area, pressure value and pressure waveform of each insulating pad of the transformer to be tested under the second test condition are recorded.

[0083] Table 1

[0084]

[0085]

[0086] Then, a steady-state force of 2MPa, i.e., Fs=1.8kN, is applied to the insulating spacer of the transformer to be tested according to the third test condition (electromagnetic impact force amplitude 2MPa, electromagnetic impact force time interval 2 minutes, electromagnetic impact force number 1 time) for 2 minutes, and the deformation, thickness, area, pressure value and pressure waveform of the insulating spacer under the third test condition are recorded to obtain the final second deformation, second thickness, second area, second pressure value and second pressure waveform. The first test condition is the first time that a force is applied to the insulating spacer of the transformer to be tested. The third test condition is to apply a force to the insulating spacer of the transformer to be tested after it has been subjected to 9 cycles. In order to eliminate the cumulative effect of the force, the electromagnetic impact force time interval corresponding to the third test condition is longer, so as to obtain the final stable data. Figure 3 It can be seen that except for the slight difference between the first cycle and the set value, the dynamic pressure waveforms of other cycles are consistent with the set parameter values, which verifies the effectiveness and practicality of the simulation of the dynamic short-circuit electromagnetic force impact test of the transformer insulation pad in this embodiment. At the same time, the amplitude of the dynamic short-circuit force that the pad can withstand can be determined by adjusting the size of Fm.

[0087] Specifically, in the prior art, the theoretical verification of the short-circuit resistance of transformer insulation pads is carried out. However, due to the lack of dynamic short-circuit electromagnetic force test data support, it is difficult to accurately reflect the dynamic characteristics of the insulation pads during the short-circuit process, and the effectiveness of the theoretical verification of the short-circuit resistance of transformer insulation pads cannot be guaranteed. Under short-circuit conditions, a large short-circuit current will flow through the winding, and the short-circuit current waveform is as follows: Figure 4 As shown, it is a periodic and decaying waveform (stable after several cycles). Short-circuit current will generate huge electromagnetic force in the winding. The electromagnetic force of the transformer winding can be decomposed into radial short-circuit force and axial short-circuit force. Usually, the dynamic characteristics of transformer short-circuit refer to the change process caused by axial force. The calculation expression of electromagnetic force is F = BI d L, where B is the winding leakage flux, which depends on the short-circuit current I d The size and spatial position of the winding, L is the length of the winding. The transformer winding and insulating spacer structure can be equivalent to a "mass-spring" model. The axial force on the transformer winding is transmitted to the insulating spacer. The dynamically changing axial force causes dynamic changes in the insulating spacer and may cause mechanical damage to the insulating spacer, thereby causing the spacer's short-circuit resistance to decrease and causing internal faults. This embodiment sets a dynamic force that changes with time to simulate the electric force generated by the equivalent short-circuit current and applies it to the insulating spacer, so as to achieve the effect of the transformer insulating spacer being impacted by dynamic force.

[0088] By implementing this embodiment, an insulating pad of a transformer to be tested is obtained, and a first performance parameter of the insulating pad of the transformer to be tested, which is used to represent the initial performance, is tested; a short-circuit electromagnetic force impact test condition is configured for the insulating pad of the transformer to be tested; wherein the insulating pad of the transformer to be tested corresponds to a plurality of short-circuit electromagnetic force impact test conditions; each short-circuit electromagnetic force impact test condition corresponds to an electromagnetic impact force amplitude, an electromagnetic impact force time interval, and an electromagnetic impact force number; a simulated short-circuit electromagnetic force impact test is performed on the insulating pad of the transformer to be tested according to the short-circuit electromagnetic force impact test condition corresponding to the insulating pad of the transformer to be tested; a second performance parameter of the insulating pad of the transformer to be tested that has undergone the simulated short-circuit electromagnetic force impact test is tested, and the second performance parameter of the insulating pad of the transformer to be tested is compared with the first performance parameter to obtain a first comparison result representing a performance change; and the short-circuit electromagnetic force resistance capability of the insulating pad of the transformer to be tested is determined according to the first comparison result. By performing a simulated short-circuit electromagnetic force impact test on the transformer insulating pad, instead of directly performing an impact test on the transformer body, the configured short-circuit electromagnetic force impact test conditions can simulate the working environment of the transformer insulating pad under normal operation, and the simulated short-circuit electromagnetic force impact test is performed on the transformer insulating pad to be tested under the short-circuit electromagnetic force impact test conditions. By comparing the first performance parameter and the second performance parameter, the specific change in the performance of the insulating pad after being subjected to the short-circuit electromagnetic force impact can be obtained, so as to determine the short-circuit electromagnetic force resistance of the transformer insulating pad to be tested according to the first comparison result. The test conditions are not demanding, the test cost is low, and large-scale promotion and application can be carried out.

[0089] See also Figure 5 , is a schematic diagram of a structure of a transformer insulation pad resistance to short-circuit electromagnetic force impact assessment system provided by an embodiment of the present invention, comprising:

[0090] A pad parameter acquisition module, used to acquire the insulating pad of the transformer to be tested, and test a first performance parameter of the insulating pad of the transformer to be tested, which is used to represent the initial performance;

[0091] A condition configuration module is used to configure the short-circuit electromagnetic force impact test conditions of the transformer insulation pad to be tested; wherein the transformer insulation pad to be tested corresponds to a plurality of short-circuit electromagnetic force impact test conditions; each short-circuit electromagnetic force impact test condition corresponds to an electromagnetic impact force amplitude, an electromagnetic impact force time interval and an electromagnetic impact force number;

[0092] A simulation test module, used for performing a simulated short-circuit electromagnetic force impact test on the insulation pad of the transformer to be tested according to the short-circuit electromagnetic force impact test conditions corresponding to the insulation pad of the transformer to be tested;

[0093] The insulating pad evaluation module is used to test the second performance parameter of the insulating pad of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, and compare the second performance parameter of the insulating pad of the transformer to be tested with the first performance parameter to obtain a total comparison result used to represent the performance change; and determine the short-circuit electromagnetic force resistance capability of the insulating pad of the transformer to be tested based on the total comparison result.

[0094] The present invention provides a transformer insulating pad resistance to short-circuit electromagnetic force impact assessment system, which obtains the transformer insulating pad to be tested according to a pad parameter acquisition module, and tests the first performance parameter of the transformer insulating pad to be tested for indicating the initial performance; configures the short-circuit electromagnetic force impact test condition of the transformer insulating pad to be tested according to the condition configuration module; wherein the transformer insulating pad to be tested corresponds to a plurality of short-circuit electromagnetic force impact test conditions; each short-circuit electromagnetic force impact test condition corresponds to an electromagnetic impact force amplitude, an electromagnetic impact force time interval and an electromagnetic impact force number; in a simulation test module, performs a simulated short-circuit electromagnetic force impact test on the transformer insulating pad to be tested according to the short-circuit electromagnetic force impact test condition corresponding to the transformer insulating pad to be tested; tests the second performance parameter of the transformer insulating pad to be tested after the simulated short-circuit electromagnetic force impact test through the insulating pad assessment module, and compares the second performance parameter of the transformer insulating pad to be tested with the first performance parameter to obtain a total comparison result for indicating the performance change; and determines the short-circuit electromagnetic force resistance capability of the transformer insulating pad to be tested according to the total comparison result. By performing a simulated short-circuit electromagnetic force impact test on the transformer insulating pad, instead of directly performing an impact test on the transformer body, the configured short-circuit electromagnetic force impact test conditions can simulate the working environment of the transformer insulating pad under normal operation, and the simulated short-circuit electromagnetic force impact test is performed on the transformer insulating pad to be tested under the short-circuit electromagnetic force impact test conditions. By comparing the first performance parameter and the second performance parameter, the specific change in the performance of the insulating pad after being subjected to the short-circuit electromagnetic force impact can be obtained, so as to determine the short-circuit electromagnetic force resistance of the transformer insulating pad to be tested according to the first comparison result. The test conditions are not demanding, the test cost is low, and large-scale promotion and application can be carried out.

[0095] It should be noted that the system embodiment described above is merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the drawings of the system embodiment provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0096] Those skilled in the art can clearly understand that, for the sake of convenience and brevity, the specific working process of the system described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0097] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for evaluating the short-circuit electromagnetic force impact resistance of transformer insulation pads. It is characterized in that include: Obtaining an insulating spacer of the transformer to be tested, and testing a first performance parameter of the insulating spacer of the transformer to be tested, which is used to represent initial performance; Configure the short-circuit electromagnetic force impact test conditions of the transformer insulation pad to be tested; wherein the transformer insulation pad to be tested corresponds to a plurality of short-circuit electromagnetic force impact test conditions; each short-circuit electromagnetic force impact test condition corresponds to an electromagnetic impact force amplitude, an electromagnetic impact force time interval and an electromagnetic impact force number; Performing a simulated short-circuit electromagnetic force impact test on the insulation pad of the transformer to be tested according to the short-circuit electromagnetic force impact test conditions corresponding to the insulation pad of the transformer to be tested; The second performance parameter of the insulating spacer of the transformer to be tested which has undergone a simulated short-circuit electromagnetic force impact test is tested, and the second performance parameter of the insulating spacer of the transformer to be tested is compared with the first performance parameter to obtain a total comparison result for indicating a performance change; and the short-circuit electromagnetic force resistance capability of the insulating spacer of the transformer to be tested is determined based on the total comparison result.

2. A method for evaluating the resistance of transformer insulation pads to short-circuit electromagnetic force impact as claimed in claim 1, It is characterized in that In the case where the first performance parameter is a mechanical performance parameter, the determination of the short-circuit electromagnetic force resistance capability of the transformer insulation pad to be tested includes: Compare the first mechanical property parameter used to represent the insulating spacer of the transformer to be tested before the simulated short-circuit electromagnetic force impact test with the second mechanical property parameter used to represent the insulating spacer after the simulated short-circuit electromagnetic force impact test, and obtain a first comparison result used to represent the change of the mechanical property of the insulating spacer of the transformer to be tested in the total comparison result; The short-circuit resistance capability of the insulating spacer of the transformer to be tested is determined according to the first comparison result.

3. A method for evaluating the resistance of transformer insulation pads to short-circuit electromagnetic force impact as claimed in claim 1, It is characterized in that In the case where the first performance parameter is an appearance structure parameter, the determination of the short-circuit electromagnetic force resistance capability of the transformer insulation pad to be tested includes: Compare the first appearance structure parameter used to represent the insulating spacer of the transformer to be tested before the simulated short-circuit electromagnetic force impact test with the second appearance structure parameter used to represent the insulating spacer of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, and obtain a second comparison result used to represent the appearance structure change of the insulating spacer of the transformer to be tested in the total comparison result; The short-circuit electromagnetic force resistance capability of the insulating spacer of the transformer to be tested is determined according to the second comparison result.

4. A method for evaluating the resistance of transformer insulation pads to short-circuit electromagnetic force impact as claimed in claim 2, It is characterized in that The first mechanical performance parameter includes: a first pressure waveform and a first pressure value; the second mechanical performance parameter includes: a second pressure waveform and a second pressure value; The first mechanical property parameter used to represent the insulating spacer of the transformer to be tested before the simulated short-circuit electromagnetic force impact test is compared with the second mechanical property parameter used to represent the insulating spacer of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, including: The second pressure waveform and the second pressure value of the transformer insulation pad to be tested after the simulated short-circuit electromagnetic force impact test are respectively compared with the initial first pressure waveform and the first pressure value of the transformer insulation pad to be tested.

5. A method for evaluating the resistance of transformer insulation pads to short-circuit electromagnetic force impact as claimed in claim 3, It is characterized in that The first appearance structure parameters include: a first deformation amount, a first thickness and a first area; the second appearance structure parameters include: a second deformation amount, a second thickness and a second area; Comparing the first appearance structure parameter used to represent the insulation pad of the transformer to be tested before the simulated short-circuit electromagnetic force impact test with the second appearance structure parameter used to represent the insulation pad of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, including: The first deformation amount, the first thickness and the first area of ​​the insulating pad of the transformer to be tested before the simulated short-circuit electromagnetic force impact test are compared with the second deformation amount, the second thickness and the second area after the simulated short-circuit electromagnetic force impact test.

6. A method for evaluating the resistance of transformer insulation pads to short-circuit electromagnetic force impact as claimed in claim 1, It is characterized in that The short-circuit electromagnetic force impact test condition includes: a first test condition for representing a static electromagnetic impact force test, a second test condition for representing a dynamic electromagnetic impact force test, and a third test condition for representing a static electromagnetic impact force test after the dynamic electromagnetic impact force test; The electromagnetic impact force amplitude corresponding to the first test condition is consistent with the electromagnetic impact force amplitude corresponding to the third test condition; The number of electromagnetic impact forces corresponding to the first test condition is consistent with the number of electromagnetic impact forces corresponding to the third test condition.

7. A method for evaluating the resistance of transformer insulation pads to short-circuit electromagnetic force impact as claimed in claim 6, It is characterized in that The electromagnetic impact force corresponding to the second test condition presents periodic changes; The calculation of the electromagnetic impact force corresponding to the second test condition includes: The electromagnetic impact force corresponding to the second test condition is calculated according to the electromagnetic impact force amplitude corresponding to the second test condition, the preset electromagnetic impact force frequency and the preset period interval.

8. A method for evaluating the resistance of transformer insulation pads to short-circuit electromagnetic force impact as claimed in claim 1, It is characterized in that Also includes: Before carrying out a simulated short-circuit electromagnetic force impact test on the insulating pad of the transformer to be tested, an oil immersion treatment is carried out.

9. A method for evaluating the resistance of transformer insulation pads to short-circuit electromagnetic force impact as claimed in claim 1, It is characterized in that The transformer insulation pad to be tested is composed of a plurality of insulation paperboards with the same thickness stacked together.

10. A transformer insulation pad resistance to short-circuit electromagnetic force impact assessment system, It is characterized in that include: A pad parameter acquisition module, used to acquire the insulating pad of the transformer to be tested, and test a first performance parameter of the insulating pad of the transformer to be tested, which is used to represent the initial performance; A condition configuration module is used to configure the short-circuit electromagnetic force impact test conditions of the transformer insulation pad to be tested; wherein the transformer insulation pad to be tested corresponds to a plurality of short-circuit electromagnetic force impact test conditions; each short-circuit electromagnetic force impact test condition corresponds to an electromagnetic impact force amplitude, an electromagnetic impact force time interval and an electromagnetic impact force number; A simulation test module, used for performing a simulated short-circuit electromagnetic force impact test on the insulation pad of the transformer to be tested according to the short-circuit electromagnetic force impact test conditions corresponding to the insulation pad of the transformer to be tested; The insulating pad evaluation module is used to test the second performance parameter of the insulating pad of the transformer to be tested after the simulated short-circuit electromagnetic force impact test, and compare the second performance parameter of the insulating pad of the transformer to be tested with the first performance parameter to obtain a total comparison result used to represent the performance change; and determine the short-circuit electromagnetic force resistance capability of the insulating pad of the transformer to be tested based on the total comparison result.

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