Equivalent test device and test method for transformer coil

Abstract

The present invention relates to the technical field of transformer testing equipment, and relates to an equivalent testing device and testing method for transformer coils. The equivalent testing device includes a bearing structure, an electromagnetic driving component, an equivalent sample and a testing component; the electromagnetic driving component includes a driving coil, a driven coil and a transmission structure, and the driving coil and the driven coil are magnetically matched; the equivalent sample is connected to the output end of the transmission structure; the testing component includes a high-speed camera and an infrared thermometer. In the equivalent testing device of this embodiment, by setting the electromagnetic driving component to connect the equivalent sample, the driving force of the electromagnetic driving component can be changed by adjusting the pulse power source voltage to simulate the influence of the electric force on the equivalent winding under different short-circuit current conditions, and at the same time, the temperature can be increased by inputting a long pulse current to the equivalent sample to change the input energy, thereby realizing the simulation of the equivalent sample under various short-circuit fault situations, and the test is convenient and the use effect is good.

Description

Technical Field

[0001] The present invention relates to the technical field of transformer testing equipment, and in particular to an equivalent testing device and a testing method for a transformer coil. Background Art

[0002] The quality of the transformer is a key factor affecting the safe and reliable operation of the power system, and the detection of coil materials is a key link in the control of the power system. In recent years, short-circuit accidents of transformers have occurred from time to time, which has had a great impact on the safe operation of the power grid. When a short circuit suddenly occurs on the secondary side, there will be a large amount of short-circuit current in the coil, which will not only bring a large electromagnetic field to the various components of the transformer, but also cause the temperature of the coil to rise sharply. Both of these situations will cause the deformation of the coil material, which will have a certain impact on the normal operation and reliability of the transformer. Therefore, the short-circuit test of the transformer was verified, and the deformation of the coil winding was used to measure the damage of the material in the test.

[0003] However, this method requires the use of the transformer as a whole for testing, the test materials are expensive, the assembly is difficult, and it is difficult to conduct continuous material testing. Moreover, it is difficult for the detection sensor to achieve signal transmission inside the transformer, which is prone to signal interference, poor reliability, and easy to damage the detection equipment. Therefore, how to design a test method that can effectively test its structure and performance is a technical problem that urgently needs to be solved. Summary of the invention

[0004] The present invention provides an equivalent testing device and a testing method for a transformer coil, which are used to achieve the purpose of quickly and effectively detecting a transformer circuit.

[0005] The present invention proposes an equivalent test device for transformer coils, comprising:

[0006] load-bearing structure;

[0007] An electromagnetic drive assembly, comprising a drive coil, a driven coil and a transmission structure, wherein the drive coil is magnetically matched with the driven coil, the driven coil is connected to an input end of the transmission structure and is used to drive the transmission structure to move in a first direction;

[0008] an equivalent sample connected to an output end of the transmission structure, and the transmission structure is used to drive the equivalent sample to move along the first direction; and

[0009] The testing assembly comprises a high-speed camera and an infrared thermometer, wherein the high-speed camera and the infrared thermometer are both arranged toward the equivalent sample.

[0010] According to one embodiment of the present invention, the transmission structure includes a pushing rod and a driven rod, the axial ends of the pushing rod are respectively connected to the driven coil and the equivalent sample, the driven rod is connected to one end of the equivalent sample away from the pushing rod, and the pushing rod, the equivalent sample and the driven rod are coaxially arranged.

[0011] According to one embodiment of the present invention, the electromagnetic drive component also includes a stress wave amplifier, which is respectively connected to the driven coil and the push rod, and one end of the push rod away from the equivalent sample can be movably inserted into the drive coil and the driven coil.

[0012] According to an embodiment of the present invention, the stress wave amplifier, the pushing rod and the driven rod are made of elastic steel.

[0013] According to one embodiment of the present invention, the equivalent sample includes an equivalent winding and a wiring part, the number of the wiring parts is two, and the two wiring parts are respectively connected to the opposite ends of the equivalent winding, and the side of the wiring part away from the equivalent winding is connected to the transmission structure.

[0014] According to an embodiment of the present invention, the equivalent winding is arranged in a spiral structure along the first direction, and the outer diameter of the equivalent winding is smaller than the diameter of the pushing rod.

[0015] According to one embodiment of the present invention, the equivalent sample also includes a positioning boss and a positioning convex portion, which is connected to a side of the wiring portion away from the equivalent winding and is enclosed with the wiring portion to form a space for fixing the push rod, and the push rod abuts against the inner side of the positioning convex portion.

[0016] According to one embodiment of the present invention, the high-speed camera and the infrared thermometer are arranged at 90°.

[0017] According to one embodiment of the present invention, the test component also includes a spectrometer, which is arranged between the high-speed camera and the infrared thermometer, and the high-speed camera and the infrared thermometer are symmetrically arranged on opposite sides of the spectrometer, and the angle between the spectrometer and the first direction is 45°.

[0018] The present invention also provides an equivalent test method for transformer coils, comprising the following steps:

[0019] Providing an equivalent sample, and connecting the equivalent sample to a power source;

[0020] Providing an electromagnetic drive assembly, the electromagnetic drive assembly comprising a drive coil and a driven coil, the drive coil and the driven coil being magnetically matched;

[0021] A test assembly is provided, which includes a high-speed camera and an infrared thermometer, wherein the high-speed camera and the infrared thermometer are arranged on one side of the equivalent sample.

[0022] Implementing the embodiments of the present invention has the following beneficial effects:

[0023] In the equivalent test device of the present embodiment, by setting an electromagnetic drive component to connect to the equivalent sample, the driving force of the electromagnetic drive component can be changed by adjusting the pulse power source voltage to simulate the influence of the electric force on the equivalent winding under different short-circuit current conditions. At the same time, the temperature can be increased by inputting a long pulse current into the equivalent sample to change the input energy, thereby realizing the simulation of equivalent samples under various short-circuit fault situations, with convenient testing and good use effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] in:

[0026] Figure 1 is a schematic diagram of the structure of an equivalent test device in an embodiment of the present invention;

[0027] Figure 2 is a schematic diagram of the cross-sectional structure of an equivalent sample in an embodiment of the present invention;

[0028] Figure 3 is a circuit diagram of an equivalent test device in an embodiment of the present invention;

[0029] Figure 4 It is a schematic flow chart of the equivalent testing method of the present invention;

[0030] Reference numerals:

[0031] 10. Equivalent test device;

[0032] 110, fixed end cover; 120, first load-bearing bracket; 130, second load-bearing bracket; 140, third load-bearing bracket;

[0033] 200, electromagnetic drive assembly; 210, drive coil; 220, driven coil; 230, transmission structure; 231, push rod; 232, driven rod; 240, stress wave amplifier;

[0034] 300, equivalent sample; 310, equivalent winding; 320, connection part; 321, connection hole; 330, positioning protrusion;

[0035] 400. test component; 410. high-speed camera; 420. infrared thermometer; 430. spectroscope. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] See also Figures 1 to 4 As shown, an embodiment of the present invention provides an equivalent test device 10 for transformer coils, which includes a bearing structure, an electromagnetic drive component 200, an equivalent sample 300 and a test component 400; the electromagnetic drive component 200 includes a drive coil 210, a driven coil 220 and a transmission structure 230, the drive coil 210 and the driven coil 220 are magnetically matched, the driven coil 220 is connected to the input end of the transmission structure 230, and is used to drive the transmission structure 230 to move along a first direction; the equivalent sample 300 is connected to the output end of the transmission structure 230, and the transmission structure 230 is used to drive the equivalent sample 300 to move along the first direction; the test component 400 includes a high-speed camera 410 and an infrared thermometer 420, and the high-speed camera 410 and the infrared thermometer 420 are both arranged toward the equivalent sample 300.

[0038] In the equivalent test device 10 of the present embodiment, by setting the electromagnetic drive component 200 to be connected to the equivalent sample 300, the driving force of the electromagnetic drive component 200 can be changed by adjusting the pulse power source voltage to simulate the influence of the electric force on the equivalent winding 310 under different short-circuit current conditions. At the same time, the temperature can be increased by inputting a long pulse current into the equivalent sample 300 to change the input energy, thereby realizing the simulation of the equivalent sample 300 under various short-circuit fault situations, and the test is convenient and the use effect is good.

[0039] It should be noted that, see Figure 1 As shown, the X direction in the figure is defined as the first direction, and the Y direction perpendicular to the X direction is defined as the second solution, and the X direction is coaxially arranged with the equivalent sample 300, and the Y direction is parallel to the radial direction of the equivalent sample 300.

[0040] Specifically, the transmission structure 230 includes a pushing rod 231 and a driven rod 232. The axial ends of the pushing rod 231 are respectively connected to the driven coil 220 and the equivalent sample 300. The driven rod 232 is connected to an end of the equivalent sample 300 away from the pushing rod 231. The pushing rod 231, the equivalent sample 300 and the driven rod 232 are coaxially arranged and parallel to the X direction.

[0041] In this embodiment, the driving coil 210 and the driven coil 220 can generate magnetic force after being energized, and various driving forces can be formed between the driving coil 210 and the driven coil 220 by controlling the input current, so that the equivalent sample 300 can move under conditions such as reciprocating motion and unidirectional movement, thereby achieving the testing purpose under various environments; by setting a push rod 231 to connect the driven coil 220 and the equivalent sample 300, the push rod 231 can move axially along the X direction under the driving force of the driven coil 220, and the driven rod 232 can be fixedly connected to the external structure, thereby ensuring that the axial ends of the equivalent sample 300 can move relative to each other to achieve the detection purpose.

[0042] Furthermore, the electromagnetic drive component 200 also includes a stress wave amplifier 240, which is respectively connected to the driven coil 220 and the push rod 231, and the end of the push rod 231 away from the equivalent sample 300 can be movably inserted into the drive coil 210 and the driven coil 220.

[0043] See also Figure 1 As shown, in this embodiment, the stress wave amplifier 240 is roughly a conical structure. A circular groove is opened on one side of the stress wave amplifier 240, and the driven coil 220 is fixed in the circular groove of the stress wave amplifier 240. An electromagnetic driving force can be generated by coupling the driving coil 210 and the driven coil 220 to achieve the driving effect of the electromagnetic driving component 200; by setting the stress wave amplifier 240 to be conical, the stress wave amplifier 240 can have a larger installation range to ensure the driving effect of the driven coil 220.

[0044] Specifically, the stress wave amplifier 240 , the pushing rod 231 and the driven rod 232 are made of elastic steel.

[0045] By making the stress wave amplifier 240, the pushing rod 231 and the driven rod 232 of elastic steel material, it can be ensured that the equivalent sample 300 does not produce plastic deformation during movement, reducing the stress wave amplitude during pushing, thereby improving the reliability of the device and the detection accuracy.

[0046] See also Figure 2As shown, in one embodiment, the equivalent sample 300 includes an equivalent winding 310 and a wiring portion 320 , the number of the wiring portions 320 is two, and the two wiring portions 320 are respectively connected to opposite ends of the equivalent winding 310 , and the side of the wiring portion 320 away from the equivalent winding 310 is connected to the transmission structure 230 .

[0047] In this embodiment, the equivalent sample 300 can be processed by cutting and welding to form an integral structure of the equivalent winding 310 and the wiring part 320. During the test, the equivalent sample 300 is firstly connected to the equivalent sample 300 through the two wiring parts 320 to realize a loop connection, so as to heat the equivalent sample 300.

[0048] Specifically, see Figure 2 As shown, the equivalent winding 310 is arranged in a spiral structure along the first direction, and the outer diameter of the equivalent winding 310 is smaller than the diameter of the push rod 231 .

[0049] Furthermore, the equivalent sample 300 also includes a positioning protrusion 330 , which is connected to the side of the wiring portion 320 away from the equivalent winding 310 , and is enclosed with the wiring portion 320 to form a space for fixing the push rod 231 , and the push rod 231 abuts against the inner side of the positioning protrusion 330 .

[0050] In this embodiment, the positioning protrusion 330 is fixedly connected to the wiring portion 320 by cutting, welding, etc. The positioning protrusion 330 is an annular structure and corresponds to the size of the push rod 231. The positioning protrusion 330 is connected to the push rod 231 so that the equivalent sample 300 is coaxially connected to the push rod 231, and the movement between the two along the Y direction is limited.

[0051] Specifically, the wiring portion 320 is provided with a wiring hole 321, and the equivalent winding 310 is connected to the circuit of the third power source through the wiring hole 321. In one embodiment, the wiring hole 321 is provided on the wiring portion 320 and is a through hole, which is used to connect to an external circuit such as the third power source, and the temperature of the equivalent sample 300 is increased by injecting current energy.

[0052] See also Figure 1 As shown, in one embodiment, the high-speed camera 410 and the infrared thermometer 420 are arranged at 90 degrees.

[0053] In this configuration, the high-speed camera 410 and the infrared thermometer 420 are both facing the equivalent winding 310 of the equivalent sample 300 to sense relevant data such as deformation and temperature of the equivalent sample 300; in this embodiment, the test component 400 also includes a control module such as a PLC, an industrial computer, a single-chip microcomputer, etc. The control module signal is connected to the high-speed camera 410 and the infrared thermometer 420, and is used to obtain and calculate the relevant signals sensed by the high-speed camera 410 and the infrared thermometer 420, thereby obtaining the test signal of the equivalent sample 300.

[0054] Furthermore, the test assembly 400 also includes a spectroscope 430, which is disposed between the high-speed camera 410 and the infrared thermometer 420, and the high-speed camera 410 and the infrared thermometer 420 are symmetrically disposed on opposite sides of the spectroscope 430, and the angle between the spectroscope 430 and the first direction is 45°.

[0055] In this embodiment, the high-speed camera 410 is arranged along the Y direction, the infrared thermometer 420 is arranged along the X direction, and the spectrometer 430 is arranged between the high-speed camera 410 and the infrared thermometer 420. The high-speed camera 410 and the infrared thermometer 420 can obtain the signal of the equivalent sample 300 in real time through the spectrometer 430, and at the same time make the combination of the test component 400 and the equivalent sample 300 have a more compact structure.

[0056] See also Figure 1 As shown, in one embodiment, the bearing structure includes a fixed end cover 110, a first bearing bracket 120, a second bearing bracket 130 and a third bearing bracket 140, the fixed end cover 110 is fixed to the side of the driving coil 210 away from the driven coil 220, the first bearing bracket 120 is connected to the fixed end cover 110, the second bearing bracket 130 is connected to the pushing rod 231, and the third bearing bracket 140 is connected to the driven rod 232.

[0057] In this embodiment, the stress wave amplifier 240 is sleeved with the push rod 231, and the end of the push rod 231 away from the stress wave amplifier 240 is inserted into the positioning protrusion 330, and is interconnected with the equivalent sample 300 to form a compression plane to ensure that there is no gap during the transmission process. The same is true for the driven rod 232, and the right side of the driven rod 232 is connected to the fixed plane. The high-speed camera 410 and the infrared thermometer 420 are preferably installed on non-adjacent platforms to ensure that the non-contact diagnosis of the two will not be affected by vibration, and the use effect is good.

[0058] In one embodiment, the cross-sections of the driving coil 210 and the driven coil 220 are both circular, and an electrode is led out from one side of the left surface of the driving coil 210 and coincides with the opening on the fixed end cover 110. The power supply can be connected to the electrode of the driving coil 210 through the fixed end cover 110, and eight fixing holes are opened on the periphery of the driving coil 210 and the driven coil 220. The driving coil 210 and the fixed end cover 110 are fixedly connected by bolts, and the right end of the fixed end cover 110 is pressed against the left surface of the driving coil 210 to form a pressing plane. Similarly, the right end of the driven coil 220 and the left end of the stress wave amplifier 240 form a pressing plane.

[0059] Specifically, when assembling the equivalent test device 10 of this embodiment, the stress wave amplifier 240 is rigidly connected to the push rod 231 and cannot rotate or move relative to each other, and a boss is welded to the outer ring of the stress wave amplifier 240, and the inner diameter of the boss is equal to the outer diameter of the driving coil 210, which is used to fix the driven coil 220 so that it is relatively fixed and non-slip between it and the stress wave amplifier 240; then the push rod 231, the driven rod 232 and the first bearing bracket 120 are fixed on the installation plane, and then the fixed end cover 110 is installed, and the free displacement of the push rod 231 and the driven rod 232 is fixed by a steel clamp, so that the push rod 231 can slide relative to the first bearing bracket 120, and the driven rod 232 can slide relative to the second bearing bracket 130.

[0060] The present invention further provides an equivalent testing method for transformer coils, which can be applied to the equivalent testing device 10 in any one of the above embodiments. Specifically, the equivalent testing method includes the following steps:

[0061] Step S100, providing an equivalent sample 300, and connecting the equivalent sample 300 to a power source;

[0062] Step S200, providing an electromagnetic drive assembly 200, wherein the electromagnetic drive assembly 200 includes a drive coil 210 and a driven coil 220, and the drive coil 210 and the driven coil 220 are magnetically matched;

[0063] Step S300 , providing a test assembly 400 , the test assembly 400 includes a high-speed camera 410 and an infrared thermometer 420 , and the high-speed camera 410 and the infrared thermometer 420 are arranged on one side of the equivalent sample 300 .

[0064] In this embodiment, three pulse power supply currents flow into the driving coil 210 and the equivalent sample 300 in a time sequence, wherein a long pulse current flows into the equivalent sample 300, and a large amount of heat is generated on the equivalent sample 300 due to the Joule heating effect, resulting in a large temperature rise, which is equivalent to the temperature rising sharply when the transformer is short-circuited. After heating, currents are simultaneously supplied to the driving coil 210 and the driven coil 220, and the driving coil 210 and the driven coil 220 generate magnetic fields respectively. The current in the coil interacts with the magnetic field to generate Lorentz force. When the same-direction current is applied, the stress wave amplifier 240 generates a stress wave on the push rod 231. When the reverse current is applied, the extrusion stress wave amplifier 240 generates a stress wave on the push rod 231. The stress wave is transmitted along the push rod 231 to the equivalent sample 300. The temperature condition and the electrodynamic condition appear on the equivalent sample 300 at the same time, causing the equivalent sample 300 to be strained under high temperature conditions. The material undergoes plastic deformation and drives the high-speed camera 410 and the infrared thermometer 420 in a time sequence to record temperature and strain data.

[0065] In the equivalent test device 10, i.e., the test method in this embodiment, the multi-physical field conditions of high current, high temperature, and deformation of the winding metal material of the transformer coil during a short-circuit fault can be simulated, thereby meeting the assessment requirements of the equivalent simulation material during a transformer short-circuit fault.

[0066] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0067] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" 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. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0068] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0069] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An equivalent test device for transformer coils, characterized in that: include: load-bearing structure; An electromagnetic drive assembly, comprising a drive coil, a driven coil and a transmission structure, wherein the drive coil is magnetically matched with the driven coil, the driven coil is connected to an input end of the transmission structure and is used to drive the transmission structure to move in a first direction; An equivalent sample connected to the output end of the transmission structure, and the transmission structure is used to drive the equivalent sample to move along the first direction; as well as A test assembly, comprising a high-speed camera and an infrared thermometer, wherein the high-speed camera and the infrared thermometer are both arranged toward the equivalent sample; The transmission structure includes a push rod and a driven rod, the axial ends of the push rod are respectively connected to the driven coil and the equivalent sample, the driven rod is connected to one end of the equivalent sample away from the push rod, and the push rod, the equivalent sample and the driven rod are coaxially arranged; the equivalent sample includes an equivalent winding and a wiring part, the number of the wiring parts is two, and the two wiring parts are respectively connected to the opposite ends of the equivalent winding, and the side of the wiring part away from the equivalent winding is connected to the transmission structure; the equivalent winding is arranged in a spiral structure along the first direction, and the outer diameter of the equivalent winding is smaller than the diameter of the push rod; The equivalent sample also includes a positioning protrusion, which is connected to a side of the wiring portion away from the equivalent winding and is enclosed with the wiring portion to form a space for fixing the push rod, and the push rod abuts against the inner side of the positioning protrusion.

2. The equivalent test device according to claim 1, characterized in that: The electromagnetic drive component also includes a stress wave amplifier, which is respectively connected to the driven coil and the push rod, and one end of the push rod away from the equivalent sample can be movably inserted into the drive coil and the driven coil.

3. The equivalent test device according to claim 2, characterized in that: The stress wave amplifier, the pushing rod and the driven rod are made of elastic steel.

4. The equivalent test device according to claim 1, characterized in that: The high-speed camera and the infrared thermometer are arranged at 90 degrees.

5. The equivalent test device according to claim 4, characterized in that: The test assembly also includes a spectroscope, which is arranged between the high-speed camera and the infrared thermometer, and the high-speed camera and the infrared thermometer are symmetrically arranged on opposite sides of the spectroscope, and the angle between the spectroscope and the first direction is 45°.

6. An equivalent test method for transformer coils, characterized in that: The equivalent test method for transformer coils is based on the equivalent test device according to any one of claims 1 to 5, and comprises the following steps: Providing an equivalent sample, and connecting the equivalent sample to a power source; Providing an electromagnetic drive assembly, the electromagnetic drive assembly comprising a drive coil and a driven coil, the drive coil and the driven coil being magnetically matched; Providing a test assembly, the test assembly comprising a high-speed camera and an infrared thermometer, wherein the high-speed camera and the infrared thermometer are arranged on one side of the equivalent sample; Three pulse power supply currents flow into the driving coil and the equivalent sample respectively in a time sequence, wherein a long pulse current flows into the equivalent sample, so that the temperature rise generated by the Joule heat effect on the equivalent sample reaches the temperature rise condition of the equivalent transformer short circuit fault, and after heating, input current begins to flow into the driving coil and the driven coil at the same time, the driving coil and the driven coil generate magnetic force by energizing, and the input current is controlled to form a variety of driving forces between the driving coil and the driven coil, so as to achieve the test purpose under various environments; A push rod is provided to connect the driven coil and the equivalent sample. The push rod moves axially along the X direction under the driving force of the driven coil. The driven rod is fixedly connected to the external structure. The axial ends of the equivalent sample can move relatively to achieve the detection purpose.

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