Fault recognition device and method based on transformer fault noise

Abstract

The invention discloses a fault recognition device and method based on transformer fault noise, and relates to the technical field of transformer monitoring. The fault recognition device based on the transformer fault noise comprises a device base arranged at the bottom of a transformer body and a detection support arranged on the side face of the transformer body, a sound gathering cover is fixedly connected to the detection support, a bearing plate is movably connected into the sound gathering cover, and an adjusting unit is arranged on the device base. According to the fault recognition device based on the transformer fault noise, the sound gathering cover is supported through the detection support, it is guaranteed that the stability of sound signals received by the sound receiver is good, then the fault recognition stability and accuracy are improved, and meanwhile the design of the adjusting unit and the bearing plate is adopted; the positions of the sound processing terminal and the sound receiver are conveniently adjusted, and the sound receiver is embedded in the detection support, so that secondary detection is performed when the signal is abnormal, and the fault identification accuracy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of transformer monitoring, and in particular to a fault identification device and method based on transformer fault noise. Background Art

[0002] The fault identification device based on transformer fault noise is a device specially designed to detect and identify transformer faults. The transformer will generate certain noise during normal operation, and when a fault occurs inside it, the noise signal will change. For example, faults such as winding deformation, looseness or core looseness will cause changes in the vibration characteristics of the transformer, thereby generating abnormal noise signals.

[0003] The device can determine whether the transformer has a fault by collecting and analyzing these noise signals. In the prior art, when some transformers used outdoors are exposed to the outside, a commonly used method is to use a bracket to install the device on the side of the transformer and maintain a specified distance from the transformer. During the use of this identification device, it is found that some transformers produce relatively small sounds, and the sound receiving signal of the identification device is weak, which is easy to cause misjudgment. In addition, on rainy days or when there is noise around the transformer, it is also easy to cause misjudgment of the identification device. This is mainly because when the external noise and the fault sound judgment signal are close, it is easy to cause misjudgment. Therefore, when the above-mentioned outdoor transformer uses the identification device, the accuracy and stability of fault identification are affected. In view of the shortcomings of the prior art, the present invention provides a fault identification device and method based on transformer fault noise to solve the above-mentioned problems. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a fault identification device and method based on transformer fault noise, which supports a sound collecting cover through a detection bracket, and collects and amplifies the operating sound of the transformer main body through the sound collecting cover, thereby ensuring that the sound signal received by the sound receiver has good stability, thereby improving the stability and accuracy of fault identification. At the same time, the design of an adjustment unit and a carrier plate is adopted to facilitate the adjustment of the position of the sound processing terminal and the sound receiver, and the sound receiver is embedded in the detection bracket, so as to perform secondary detection when the signal is abnormal. When the sound receiver is embedded in the detection bracket, it receives the sound signal transmitted from the transformer main body to the detection bracket. The sound signal is transmitted in a solid propagation manner, which reduces the influence of external environmental noise and further improves the stability and accuracy of fault identification of the transformer main body.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a fault identification device based on transformer fault noise, comprising a device base arranged at the bottom of the transformer body and a detection bracket arranged on the side of the transformer body, wherein a sound collecting cover is fixedly connected to the detection bracket;

[0006] The interior of the sound collecting cover is movably connected with a bearing plate, and the base of the device is provided with an adjustment unit for adjusting the position of the bearing plate;

[0007] A sound processing terminal is movably connected to the carrier board, and a sound receiver is arranged on the sound processing terminal.

[0008] Preferably, the adjustment unit comprises a guide rail frame fixedly connected to the device base and an adjustment platform movably connected to the guide rail frame, and the adjustment platform is provided with a push plate, and the push plate is connected to the bearing plate;

[0009] The guide rail frame is provided with a motor, an output end of the motor is provided with a screw rod, and the screw rod is threadedly connected with the adjustment platform.

[0010] Preferably, a clamping mechanism is provided between the push plate and the supporting plate, and the clamping mechanism includes a first connecting frame arranged on the push plate and a sliding rod fixedly connected to the first connecting frame, a second connecting frame is sleeved on the sliding rod, and the second connecting frame is fixedly connected to the supporting plate, and a spring is fixedly connected between the first connecting frame and the second connecting frame.

[0011] Preferably, the detection bracket is provided with a detection strip corresponding to the position of the sound receiver, and the device base is provided with a first bracket and a second bracket, and the first bracket and the second bracket are used to support the transformer body and the guide rail frame respectively.

[0012] Preferably, a reinforcement rail is provided on the guide rail frame, a first reinforcement slider is provided at the bottom of the first connecting frame, and a second reinforcement slider is provided at the bottom of the second connecting frame, and the first reinforcement slider and the second reinforcement slider are both slidably connected to the reinforcement rail.

[0013] Preferably, a sleeve is provided on the second connecting frame, the sliding rod is slidably connected to the sleeve, a limit block is provided on the sliding rod, and a plurality of groups of reinforcing ribs are provided on the push plate.

[0014] Preferably, a sleeve is provided on the carrying plate, the sound processing terminal is movably connected in the sleeve, and a locking component for limiting the position of the sound processing terminal is provided on the sleeve.

[0015] Preferably, the locking assembly includes a limit frame fixedly connected to the sleeve, the limit frame is threadedly connected to a screw rod, the screw rod is rotatably connected to a slide, the slide is provided with multiple groups of locking rods, the sound processing terminal is provided with a locking hole, and the locking rod is movably engaged in the locking hole.

[0016] Preferably, a rain shield is provided on the bearing plate for protecting the sound receiver.

[0017] The second aspect of the present invention provides a method for a fault identification device based on transformer fault noise, the method comprising the following steps: step S1, using a sound receiver to receive the sound emitted by the transformer body, using a sound processing terminal to process the received sound, when the sound is within a normal frequency range, it indicates that the transformer body is operating normally;

[0018] Step S2, when the sound processing terminal processes the received sound and the sound is abnormal, the adjustment unit is used to adjust the positions of the carrying plate, the sound processing terminal and the sound receiver so that the sound receiver is embedded in the detection bracket to perform secondary reception and detection on the transformer body;

[0019] Step S3, when the sound of the secondary detection is normal, it is judged that the transformer body is operating normally, and the adjustment unit is used to reset the carrier board, the sound processing terminal and the sound receiver, and re-inspection is performed regularly. When the sound of the secondary detection is abnormal, it is judged that the transformer body is operating faulty.

[0020] The present invention discloses a fault identification device and method based on transformer fault noise, which have the following beneficial effects:

[0021] 1. The fault identification device based on transformer fault noise provides support for the sound collecting cover through the detection bracket, and collects and amplifies the operating sound of the transformer main body through the sound collecting cover, so as to ensure the stability of the sound signal received by the sound receiver, thereby improving the stability and accuracy of fault identification. At the same time, the design of the adjustment unit and the carrier plate is adopted to facilitate the adjustment of the position of the sound processing terminal and the sound receiver, and the sound receiver is embedded in the detection bracket, so as to perform secondary detection when the signal is abnormal. When the sound receiver is embedded in the detection bracket, it receives the sound signal transmitted from the transformer main body to the detection bracket. The sound signal is transmitted in a solid transmission mode, which reduces the influence of external environmental noise and further improves the stability and accuracy of fault identification of the transformer main body.

[0022] 2. The fault identification device based on transformer fault noise, through the design of the tightening mechanism, ensures that when the adjustment unit adjusts the position of the carrying plate and makes the sound receiver and the detection bracket fit together, the sound receiver and the detection bracket are well fitted, and also provides a buffer during the contact process between the sound receiver and the detection bracket, thereby reducing the wear of the sound receiver and increasing the life of the sound receiver.

[0023] 3. The fault identification device based on transformer fault noise limits the sound processing terminal through the socket, ensuring that the sound processing terminal is easy to install and position. The design of the locking component makes it easy to quickly lock the sound processing terminal when it is clamped inside the socket, and it is also easy to quickly disassemble it later. Therefore, the sound processing terminal is easy to disassemble and maintain, and it is easy to quickly repair, maintain or replace it when the sound processing terminal fails. 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] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 It is a side view of the present invention;

[0027] Figure 3 It is a structural schematic diagram of the sound collecting cover of the present invention;

[0028] Figure 4 It is a structural schematic diagram of the tightening mechanism of the present invention;

[0029] Figure 5 It is a structural schematic diagram of the bearing plate of the present invention;

[0030] Figure 6 It is a structural schematic diagram of the sound processing terminal of the present invention;

[0031] Figure 7 It is a structural schematic diagram of the locking assembly of the present invention;

[0032] Figure 8 It is a schematic structural diagram of the reinforcement rail of the present invention.

[0033] In the figure: 1. device base; 11. first bracket; 12. second bracket; 2. transformer body; 3. detection bracket; 31. detection strip; 4. sound collecting cover; 5. bearing plate; 51. sleeve; 52. rain shield; 6. sound processing terminal; 61. sound receiver; 62. locking hole; 7. adjustment unit; 71. guide rail frame; 711. reinforcement rail; 72. adjustment table; 73. push plate; 731. reinforcement rib; 74. motor; 75. screw rod; 8. tightening mechanism; 81. first connecting frame; 811. first reinforcement slider; 82. slide rod; 821. limit block; 83. second connecting frame; 831. sleeve; 832. second reinforcement slider; 84. spring; 9. locking assembly; 91. limit frame; 92. screw rod; 93. slide table; 94. locking rod. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. 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.

[0035] The embodiment of the present application provides a fault identification device and method based on transformer fault noise, thereby solving the problem that the sound generated by some transformers is relatively small, the sound receiving signal of the identification device is weak, and it is easy to cause misjudgment. In addition, when it rains or there is noise around the transformer, it is also easy to cause misjudgment of the identification device. This is mainly because when the external noise and the fault sound judgment signal are close, it is easy to cause misjudgment. Therefore, when the above-mentioned outdoor transformer uses the identification device, the accuracy and stability of fault identification are affected.

[0036] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0037] The embodiment of the present invention discloses a fault identification device based on transformer fault noise. Figure 1 To Attachment Figure 8 As shown, it includes a device base 1 arranged at the bottom of the transformer body 2 and a detection bracket 3 arranged at the side of the transformer body 2, and a sound collecting cover 4 is fixedly connected to the detection bracket 3;

[0038] The interior of the sound collecting cover 4 is movably connected with a bearing plate 5, and the device base 1 is provided with an adjustment unit 7 for adjusting the position of the bearing plate 5;

[0039] The carrier board 5 is movably connected with a sound processing terminal 6, and the sound processing terminal 6 is provided with a sound receiver 61;

[0040] The fault identification device based on transformer fault noise provides support for the sound collecting cover 4 through the detection bracket 3, and collects and amplifies the operating sound of the transformer main body 2 through the sound collecting cover 4, so as to ensure the stability of the sound signal received by the sound receiver 61, thereby improving the stability and accuracy of fault identification. At the same time, the design of the adjustment unit 7 and the carrier plate 5 is adopted to facilitate the position adjustment of the sound processing terminal 6 and the sound receiver 61, and the sound receiver 61 is embedded in the detection bracket 3, so as to perform secondary detection when the signal is abnormal. When the sound receiver 61 is embedded in the detection bracket 3, it receives the sound signal transmitted from the transformer main body 2 to the detection bracket 3. The sound signal is transmitted in a solid propagation manner, which reduces the influence of external environmental noise and further improves the stability and accuracy of fault identification of the transformer main body 2.

[0041] The adjustment unit 7 includes a guide rail frame 71 fixedly connected to the device base 1 and an adjustment platform 72 movably connected to the guide rail frame 71. The adjustment platform 72 is provided with a push plate 73, which is connected to the bearing plate 5. The guide rail frame 71 is provided with a motor 74, and the output end of the motor 74 is provided with a screw rod 75, which is threadedly connected to the adjustment platform 72.

[0042] The adjustment unit 7 has a compact structure and is easy to operate. When the position of the supporting plate 5 needs to be adjusted, it can be directly driven by the motor 74. When the motor 74 is working, it drives the screw rod 75 to rotate, the screw rod 75 drives the adjustment platform 72 to move, and the adjustment platform 72 drives the supporting plate 5 to move. The sound processing terminal 6 and the sound receiver 61 are driven to move through the supporting plate 5 to achieve position adjustment of the sound receiver 61. When the sound receiver 61 contacts the detection bracket 3, solid sound transmission detection is performed. When the sound receiver 61 is in the initial position, air sound transmission detection is performed. When the two detection methods evaluate the operating sound of the transformer main body 2, it is convenient to remove the influence of external noise and improve the fault identification stability and accuracy of the transformer main body 2.

[0043] A tightening mechanism 8 is provided between the push plate 73 and the load-bearing plate 5. The tightening mechanism 8 includes a first connecting frame 81 provided on the push plate 73 and a slide bar 82 fixedly connected to the first connecting frame 81. A second connecting frame 83 is sleeved on the slide bar 82. The second connecting frame 83 is fixedly connected to the load-bearing plate 5. A spring 84 is fixedly connected between the first connecting frame 81 and the second connecting frame 83.

[0044] The device is designed with a pressing mechanism 8, so that when the adjusting unit 7 adjusts the position of the carrying plate 5 and makes the sound receiver 61 fit with the detection bracket 3, the sound receiver 61 and the detection bracket 3 are well fitted, and a buffer is provided during the contact process between the sound receiver 61 and the detection bracket 3, thereby reducing the wear of the sound receiver 61 and improving the life of the sound receiver 61;

[0045] When the adjustment unit 7 adjusts the movement of the supporting plate 5 and drives the sound processing terminal 6 and the sound receiver 61 to move and touch the detection bracket 3, it will drive the first connecting frame 81 and the second connecting frame 83 to move toward each other and squeeze the spring 84. The sliding rod 82 slides along the second connecting frame 83. The elastic potential energy of the spring 84 increases after being compressed. On the one hand, the sound receiver 61 is buffered during the contact with the detection bracket 3. On the other hand, the elastic force of the spring 84 is applied to the second connecting frame 83 and the supporting plate 5, so that there is positive pressure between the sound receiver 61 and the detection bracket 3, maintaining a fitting state and a tight fit.

[0046] A detection strip 31 corresponding to the position of the sound receiver 61 is provided on the detection bracket 3, and a first bracket 11 and a second bracket 12 are provided on the device base 1. The first bracket 11 and the second bracket 12 are respectively used to support the transformer body 2 and the guide rail frame 71. An embedding groove corresponding to the position of the sound receiver 61 is opened on the detection strip 31, so that the sound receiver 61 is embedded with the detection bracket 3 when squeezed, thereby reducing the influence of noise in the external air and improving the accuracy of fault noise recognition of the transformer body 2.

[0047] A reinforcement rail 711 is provided on the guide rail frame 71, a first reinforcement slider 811 is provided at the bottom of the first connecting frame 81, and a second reinforcement slider 832 is provided at the bottom of the second connecting frame 83. The first reinforcement slider 811 and the second reinforcement slider 832 are both slidably connected to the reinforcement rail 711. Through the design of the reinforcement rail 711, the first reinforcement slider 811 and the second reinforcement slider 832, the first bracket 11 and the second bracket 12 are laterally supported, thereby ensuring the stability of the clamping mechanism 8.

[0048] A sleeve 831 is provided on the second connecting frame 83, and the sliding rod 82 is slidably connected to the sleeve 831. A limit block 821 is provided on the sliding rod 82, and a plurality of reinforcing ribs 731 are provided on the push plate 73. The design of the sleeve 831 ensures that the sliding rod 82 is subjected to stable force, and the limit block 821 is designed to provide a limit to the sliding rod 82 to prevent the sliding rod 82 from being separated from the second connecting frame 83. The plurality of reinforcing ribs 731 ensure that the push plate 73 has high strength, good stability, and is not easy to deform, so that the adjustment unit 7 has good adjustment stability for the supporting plate 5, the sound processing terminal 6 and the sound receiver 61.

[0049] A sleeve 51 is provided on the carrier plate 5, and the sound processing terminal 6 is movably connected in the sleeve 51. A locking assembly 9 for limiting the position of the sound processing terminal 6 is provided on the sleeve 51. The device limits the sound processing terminal 6 through the sleeve 51 to ensure that the sound processing terminal 6 is easy to install and position.

[0050] The locking assembly 9 includes a limit frame 91 fixedly connected to the sleeve 51, a screw rod 92 is threadedly connected to the limit frame 91, a slide 93 is rotatably connected to the screw rod 92, a plurality of lock rods 94 are arranged on the slide 93, a locking hole 62 is opened on the sound processing terminal 6, and the lock rod 94 is movably engaged in the locking hole 62;

[0051] The device is designed with a locking assembly 9, so that the sound processing terminal 6 can be quickly locked when it is clamped in the sleeve 51, and can also be quickly disassembled later, so that the sound processing terminal 6 is easy to disassemble and maintain, and when the sound processing terminal 6 fails, it is easy to quickly repair, maintain or replace it;

[0052] When installing the sound processing terminal 6, first clamp the sound processing terminal 6 inside the supporting plate 5. After it is fully clamped, rotate the screw rod 92 so that the screw rod 92 pushes the slide 93 to move, and the slide 93 drives the locking rod 94 to move. When the locking rod 94 is inserted into the locking hole 62, the position of the sound processing terminal 6 is locked.

[0053] A rain shield 52 for protecting the sound receiver 61 is provided on the supporting plate 5. The device provides rain shield and protection for the sound receiver 61 through the rain shield 52, ensuring that the sound receiver 61 has good stability and is less disturbed when it rains.

[0054] The second aspect of the present invention provides a method for a fault identification device based on transformer fault noise, the method comprising the following steps: step S1, using a sound receiver 61 to receive the sound emitted by the transformer main body 2, using a sound processing terminal 6 to process the received sound, when the sound is within a normal frequency range, it indicates that the transformer main body 2 is operating normally;

[0055] Step S2, when the sound processing terminal 6 processes the received sound and the sound is abnormal, the adjustment unit 7 is used to adjust the positions of the carrying plate 5, the sound processing terminal 6 and the sound receiver 61, so that the sound receiver 61 is embedded in the detection bracket 3, and the transformer body 2 is received and detected for the second time;

[0056] Step S3, when the sound of the secondary detection is normal, it is judged that the transformer main body 2 is operating normally, and the adjustment unit 7 is used to reset the carrier board 5, the sound processing terminal 6 and the sound receiver 61, and re-checks are performed regularly. When the sound of the secondary detection is abnormal, it is judged that the transformer main body 2 is operating faulty.

[0057] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0058] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A fault identification device based on transformer fault noise, comprising a device base (1) arranged at the bottom of a transformer body (2) and a detection bracket (3) arranged at the side of the transformer body (2), characterized in that: The detection bracket (3) is fixedly connected with a sound collecting cover (4); The interior of the sound collecting cover (4) is movably connected to a bearing plate (5), and the device base (1) is provided with an adjustment unit (7) for adjusting the position of the bearing plate (5); A sound processing terminal (6) is movably connected to the carrier plate (5), and a sound receiver (61) is provided on the sound processing terminal (6).

2. A fault identification device based on transformer fault noise according to claim 1, characterized in that: The adjustment unit (7) comprises a guide rail frame (71) fixedly connected to the device base (1) and an adjustment platform (72) movably connected to the guide rail frame (71), wherein a push plate (73) is provided on the adjustment platform (72), and the push plate (73) is connected to the bearing plate (5); The guide rail frame (71) is provided with a motor (74), an output end of the motor (74) is provided with a screw rod (75), and the screw rod (75) is threadedly connected to the adjustment platform (72).

3. A fault identification device based on transformer fault noise according to claim 2, characterized in that: A clamping mechanism (8) is provided between the push plate (73) and the supporting plate (5), and the clamping mechanism (8) comprises a first connecting frame (81) arranged on the push plate (73) and a sliding rod (82) fixedly connected to the first connecting frame (81), a second connecting frame (83) is sleeved on the sliding rod (82), and the second connecting frame (83) is fixedly connected to the supporting plate (5), and a spring (84) is fixedly connected between the first connecting frame (81) and the second connecting frame (83).

4. A fault identification device based on transformer fault noise according to claim 2, characterized in that: The detection bracket (3) is provided with a detection strip (31) corresponding to the position of the sound receiver (61), and the device base (1) is provided with a first bracket (11) and a second bracket (12), wherein the first bracket (11) and the second bracket (12) are used to support the transformer body (2) and the guide rail frame (71) respectively.

5. The fault identification device based on transformer fault noise according to claim 3, characterized in that: The guide rail frame (71) is provided with a reinforcing rail (711), the bottom of the first connecting frame (81) is provided with a first reinforcing slider (811), the bottom of the second connecting frame (83) is provided with a second reinforcing slider (832), and the first reinforcing slider (811) and the second reinforcing slider (832) are both slidably connected to the reinforcing rail (711).

6. A fault identification device based on transformer fault noise according to claim 5, characterized in that: The second connecting frame (83) is provided with a sleeve (831), the sliding rod (82) is slidably connected to the sleeve (831), the sliding rod (82) is provided with a limit block (821), and the push plate (73) is provided with multiple groups of reinforcing ribs (731).

7. A fault identification device based on transformer fault noise according to claim 1, characterized in that: The bearing plate (5) is provided with a sleeve (51), the sound processing terminal (6) is movably clamped in the sleeve (51), and the sleeve (51) is provided with a locking assembly (9) for limiting the position of the sound processing terminal (6).

8. A fault identification device based on transformer fault noise according to claim 7, characterized in that: The locking assembly (9) comprises a limit frame (91) fixedly connected to the sleeve (51), a screw rod (92) being threadedly connected to the limit frame (91), a slide table (93) being rotatably connected to the screw rod (92), a plurality of groups of locking rods (94) being provided on the slide table (93), a locking hole (62) being provided on the sound processing terminal (6), and the locking rod (94) being movably engaged in the locking hole (62).

9. The fault identification device based on transformer fault noise according to claim 1, characterized in that: The bearing plate (5) is provided with a rain shield (52) for protecting the sound receiver (61).

10. A method for fault identification device based on transformer fault noise according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: step S1, using a sound receiver (61) to receive the sound emitted by the transformer body (2), and using a sound processing terminal (6) to process the received sound, and when the sound is within a normal frequency range, it indicates that the transformer body (2) is operating normally; Step S2, when the sound processing terminal (6) processes the received sound and the sound is abnormal, the adjustment unit (7) is used to adjust the positions of the carrier plate (5), the sound processing terminal (6) and the sound receiver (61), so that the sound receiver (61) is embedded in the detection bracket (3), and the transformer body (2) is secondary received and detected; Step S3, when the sound detected by the secondary test is normal, it is determined that the transformer main body (2) is operating normally, and the adjustment unit (7) is used to reset the carrier board (5), the sound processing terminal (6) and the sound receiver (61), and re-checks are performed regularly. When the sound detected by the secondary test is abnormal, it is determined that the transformer main body (2) is operating faulty.

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