Comprehensive testing device for conventional transformer test

Abstract

The utility model relates to the field of electrical equipment, specifically disclose a transformer routine test comprehensive testing device, the utility model discloses a plurality of function modules and the display screen for display are set up on the box integration, when detecting the transformer at high place, the user can connect the box and the transformer through the connecting line, and through a plurality of function modules, the function of transformer is detected simultaneously, can effectively avoid the trouble of detection personnel at high place frequently plugging the wiring, and then effectively reduce the repeated action of detection personnel, improve the efficiency of detection personnel, and the user can understand the detection result from the display screen, and can also be plugged through the plug interface and connect the external equipment, and the detection information is transmitted externally.

Description

Technical Field

[0001] This utility model belongs to the field of electrical equipment technology, specifically relating to a comprehensive testing device for conventional transformer testing. Background Technology

[0002] For a long time, in the critical aspects of power equipment maintenance—routine transformer commissioning tests and power outage maintenance—an operating mode heavily reliant on separate, single-function, and independent specialized instruments has dominated. Technicians on site must simultaneously dispatch and operate multiple independent sets of equipment. This not only means a wide variety of instruments and a large amount of workspace occupied, but also results in heavy and cumbersome accessories—each piece of equipment is equipped with a dedicated power supply box, a heavy test host, and bundles of specially made test leads.

[0003] The direct consequence of the decentralized nature of the instruments is that it plunges on-site testing personnel into an extremely tedious and complex cycle of operation. To complete all the tests, technicians have to repeatedly climb to the towering transformer bushing areas. Each switch to a new test means carefully disconnecting all the wiring for the previous test and then reselecting and reconnecting the corresponding dedicated cables according to the requirements of the next test. This process not only demands a high level of professionalism from the operators—requiring precise memorization of the wiring specifications, parameter settings, and safety points for each piece of equipment—but also poses a severe test to their physical strength and stability when working at heights. Maintaining balance while holding tools, identifying cable numbers, and making delicate connections on a narrow work platform is unimaginably difficult.

[0004] To address the difficulties encountered by field testing personnel in using multiple instruments in a coordinated manner during actual testing operations, improvements to the existing transformer testing equipment are necessary. Utility Model Content

[0005] In order to overcome the shortcomings of the existing technology, the purpose of this utility model is to provide a comprehensive testing device for conventional transformer testing, so as to solve the problem that the testing personnel need to use multiple devices when testing transformers, which is inconvenient to operate.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A comprehensive testing device for routine transformer testing, including:

[0008] The box body, on which a box cover is fixedly connected;

[0009] The functional modules are located inside the enclosure, including a short-circuit impedance test module, a DC resistance measurement module, a turns ratio group measurement module, and an on-load tap changer measurement module.

[0010] The insertion interface is located on the housing;

[0011] The main interface is located on the housing and connected to the functional module, and a switching connector is plugged into the main interface;

[0012] The display screen is connected to the housing and is electrically connected to the functional modules and the interface.

[0013] A grounding hole is provided on the enclosure.

[0014] Preferably, the short-circuit impedance test module includes three voltage interfaces Ua, Ub, and Uc, and also includes three current interfaces Ia, Ib, and Ic.

[0015] Preferably, the DC resistance measurement module is divided into a high-voltage DC resistance measurement submodule and a low-voltage DC resistance measurement submodule. The high-voltage DC resistance measurement submodule includes four voltage interfaces U. A U B U C U O It also includes four current interface I A I B I C I O The low-voltage DC resistance measurement submodule includes four voltage interfaces U. a U b U c U o It also includes four current interface I A I B I C I o .

[0016] Preferably, the ratio group measurement module includes two sets of interfaces: one set includes three interfaces A, B, and C, and the other set includes three interfaces a, b, and c.

[0017] Preferably, the on-load tap changer measurement module includes four interfaces: A, B, C, and O.

[0018] Preferably, the interface includes USBM1, USBM2, USBD, RS232, SD and PLJ45 interfaces.

[0019] Preferably, the switching connector includes a first positioning ring, an end head fixedly installed at the end of the first positioning ring, and a plurality of sliding connectors connected to the end head. A sleeve block is rotatably connected to the end head, and a plug rod is fixedly connected to the end of the sleeve block. A plurality of snap-fit ​​grooves that engage with the sliding connectors are fixedly connected to the inner wall of the sleeve block. One snap-fit ​​groove is connected to the plug rod. A main bus is connected to the first positioning ring, and a plurality of branch lines are fixedly connected to the main bus. Each of the branch lines corresponds one-to-one with a plurality of sliding connectors.

[0020] Preferably, the end of the terminal has multiple mounting slots, a fixed connector connected to the branch line is fixedly connected in the mounting slot, a sliding connector sleeved on the fixed connector is slidably connected in the mounting slot, an arc-shaped groove is provided on the snap-fit ​​slot, and the end of the sliding connector is hemispherical.

[0021] Preferably, a first spring is fitted onto the fixed connector head. The first spring is pre-compressed, meaning that one end of the first spring abuts against the inner wall of the mounting groove and the other end abuts against the end of the sliding connector head.

[0022] Preferably, the first positioning ring and the sleeve block are respectively provided with positioning devices. The outer wall of the first positioning ring is provided with a first positioning groove. The positioning device includes a rotating cylinder sleeved on the outside of the first positioning ring, a positioning rod fixedly installed on the inner wall of the rotating cylinder, and a second positioning ring fixedly installed on the sleeve block. The second positioning ring is provided with a second positioning groove. The positioning rod is slidably engaged in the first positioning groove and the second positioning groove. The positioning rod is configured to remain engaged in the first positioning groove after slidingly disengaging from the second positioning groove. The sleeve block is provided with a second spring. One end of the second spring abuts against the inner wall of the rotating cylinder, and the other end abuts against the second positioning ring.

[0023] Compared with the prior art, the beneficial effects of this utility model are:

[0024] This utility model integrates multiple functional modules and a display screen on the enclosure. When testing transformers at high locations, users can connect the enclosure and the transformer via connecting cables and simultaneously perform functional tests on the transformer through multiple functional modules. This effectively avoids the hassle of frequent plugging and unplugging of wires at high locations, thereby reducing repetitive actions and improving the efficiency of the testing personnel. Users can view the test results on the display screen and can also connect external devices through the interface to transmit the test information.

[0025] By setting switching connectors, main lines, and branch lines on the enclosure, one end of the main line is connected to the test device via the switching connector, and the other end is connected to the main interface of the transformer under test via various branch lines. When the user needs to test different functions of the transformer, the branch lines electrically connected to the test device can be quickly switched via the switching connector. By changing the connection status of the branch lines, the conduction line between the test device and the transformer under test can be quickly changed, thereby testing different functions of the transformer under test, reducing the number of operation steps for the operator and improving the testing speed. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the device of this utility model;

[0027] Figure 2 This is a schematic diagram of the surface structure of the device of this utility model;

[0028] Figure 3 This is the wiring diagram for the DC resistance measurement device of this utility model;

[0029] Figure 4 This is the wiring diagram for the short-circuit impedance measurement device of this utility model;

[0030] Figure 5 Wiring diagram for on-load tap changer measurement of the device of this utility model;

[0031] Figure 6 This is the wiring diagram for measuring the transformer ratio group of the device of this utility model;

[0032] Figure 7 This is a schematic diagram of the switching connector, bus, and branch connection structure of this utility model;

[0033] Figure 8 This is a schematic diagram of the cross-sectional structure of the rotating drum of this utility model. Figure 1 ;

[0034] Figure 9 This is a schematic diagram of the rotating drum structure of this utility model;

[0035] Figure 10 This is a schematic diagram of the cross-sectional structure of the rotating drum of this utility model. Figure 2 ;

[0036] Figure 11 This is a schematic diagram of the cross-sectional structure of the rotating drum of this utility model. Figure 3 ;

[0037] In the diagram: 1. Enclosure; 2. Enclosure cover; 3. Short-circuit impedance test module; 4. DC resistance measurement module; 5. Turns ratio group measurement module; 6. On-load tap changer measurement module; 7. Plug-in interface; 8. Switching connector; 81. First positioning ring; 82. First positioning groove; 83. End; 84. Mounting groove; 85. Fixed connector; 86. First spring; 87. Sliding connector; 88. Sleeve block; 89. Plug-in rod; 810. Snap-in groove; 811. Rotary drum; 812. Positioning rod; 813. Second positioning ring; 814. Second positioning groove; 815. Second spring; 9. Main bus; 10. Branch line; 11. Main interface; 12. Display screen; 13. Grounding hole. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0039] Example:

[0040] Please see Figure 1 - Figure 11 As shown, the comprehensive testing device for conventional transformer testing includes:

[0041] Box 1, with a box cover 2 fixedly connected to the box 1;

[0042] The functional modules are located inside the enclosure 1, including a short-circuit impedance test module 3, a DC resistance measurement module 4, a turns ratio group measurement module 5, and an on-load tap changer measurement module 6.

[0043] An interface 7 is provided on the housing 1;

[0044] A main interface 11 is provided on the housing 1 and connected to the functional module, and a switching connector 8 is plugged into the main interface 11;

[0045] The display screen 12 is connected to the housing 1 and electrically connected to the functional module and the interface 7. The display screen 12 is equipped with an under-screen camera to acquire the user's air gesture control commands. A photoelectric sensing device can also be set in the display screen 12 to realize non-contact anti-electric shock based optical suspended contact.

[0046] Grounding hole 13 is provided on the enclosure 1.

[0047] As can be seen from the above, by integrating multiple functional modules and a display screen 12 on the enclosure 1, when testing transformers at high locations, users can connect the enclosure 1 and the transformer via connecting cables and simultaneously perform functional tests on the transformer through multiple functional modules. This effectively avoids the trouble of frequent plugging and unplugging of wires at high locations, thereby effectively reducing repetitive actions by testing personnel and improving their efficiency. Users can view the test results on the display screen 12 and can also connect external devices via the interface 7 to transmit test information.

[0048] By setting a switching connector 8, a bus 9, and branch lines 10 on the housing 1, one end of the bus 9 is connected to the test device through the switching connector 8, and the other end is connected to the main interface 11 of the transformer under test through various branch lines 10. When the user needs to test different functions of the transformer, the branch lines 10 electrically connected to the test device can be quickly switched through the switching connector 8. By changing the connection status of the branch lines 10, the conduction line between the test device and the transformer under test can be quickly changed, thereby testing different functions of the transformer under test, reducing the number of operation steps for the operator and improving the testing speed.

[0049] Because the equipment integrates multiple functional devices and has a very sophisticated structure, in order to prevent damage during use, the equipment housing 1 and the cover 2 can be made of high-strength engineering plastics, or even alloy plates with strong resistance to deformation, in order to enhance the structural stability of the equipment.

[0050] The short-circuit impedance test module 3 includes three voltage interfaces Ua, Ub, and Uc, and three current interfaces Ia, Ib, and Ic. During measurement, the Ua, Ub, Uc and the three current interfaces Ia, Ib, and Ic of the short-circuit impedance test module 3 can be connected to the A, B, and C interfaces of the transformer respectively through wiring to measure the short-circuit impedance of the transformer. The relevant test results are displayed on the display 12.

[0051] Short-circuit impedance is an inherent and crucial parameter of a transformer, reflecting the magnitude of the leakage flux in the windings. It is closely related to the winding geometry, such as the number of turns, height, and spacing. Significant changes in short-circuit impedance are one of the most direct and sensitive indicators of winding displacement and deformation, especially increased phase-to-phase imbalance, leading to radial or axial displacement, inter-turn short circuits, and inter-strand short circuits. The enormous electromagnetic force generated by the short-circuit current is the primary cause of winding deformation. Ensuring that the actual short-circuit impedance meets design and nameplate requirements is crucial for calculating system short-circuit current, setting protection settings, and selecting equipment. Short-circuit impedance is the basis for calculating the short-circuit current that a transformer can withstand and the resulting enormous electromagnetic force. Transformers operating in parallel require very close short-circuit impedances; otherwise, uneven load distribution will occur, affecting operating efficiency and equipment lifespan. Therefore, it is necessary to integrate short-circuit impedance measurement functionality into the equipment.

[0052] The DC resistance measurement module 4 is divided into a high-voltage DC resistance measurement submodule and a low-voltage DC resistance measurement submodule. The high-voltage DC resistance measurement submodule includes four voltage interfaces U. A U B U C U O It also includes four current interface I A I B I C I OThe low-voltage DC resistance measurement submodule includes four voltage interfaces U. a U b U c U o It also includes four current interface I A I B I C I o .

[0053] When testing the DC resistance of a transformer, the testing personnel can connect the four voltage interfaces U of the DC resistance measurement module 4. A U B U C U O and four current interfaces I A I B I C I O Connect them to the A, B, C, and O terminals of the transformer respectively, and then connect the three voltage interfaces U. a U b U c and three current interfaces I A I B I C Connect the transformer to its three terminals a, b, and c respectively to measure the transformer's DC resistance. The measurement results are displayed on the display screen 12.

[0054] DC resistance measurement can detect electrical connection defects in windings, leads, and tap changers. It can identify defects such as poor welding, loose bolts or crimp connections, oxidation, dirt, burning, broken winding wires, poor contact, burnt tap changer contacts, insufficient pressure, incorrect positioning, and problems with bushing caps or lead connector connections. Furthermore, this measurement data serves as the foundation for calculating transformer load losses and can be used to assess inter-turn or inter-strand short circuits. Severe inter-turn short circuits may reduce the effective number of turns in the winding, thus causing changes in the DCR value, although this method is less sensitive than turns ratio or frequency response methods. Inter-strand short circuits typically lead to an increase in DCR and also provide important benchmark comparison data for subsequent condition monitoring and fault diagnosis.

[0055] The ratio group measurement module 5 includes two sets of interfaces: one set includes three interfaces A, B, and C, and the other set includes three interfaces a, b, and c.

[0056] When testing the three-phase turns ratio of a transformer, the testers can connect the three interfaces A, B, and C and the three interfaces a, b, and c of the turns ratio group measurement module 5 to the three interfaces A, B, and C and the three interfaces a, b, and c of the transformer respectively via connecting cables to measure the three-phase turns ratio of the transformer. The measurement results are displayed on the display screen 12.

[0057] The turns ratio serves as a verification of the accuracy of design, manufacturing, and installation, ensuring that the actual turns ratio of each transformer winding meets design and nameplate requirements, and guaranteeing that the output voltage meets system needs. Confirming the correct winding connection method and polarity is crucial for system phase synchronization, protection coordination, and parallel operation. It is used to diagnose winding faults; a short circuit reduces the effective turns of the winding, leading to an abnormal turns ratio for that winding. An out-of-tolerance turns ratio at a specific tap position indicates a potential problem with the switch contacts at that tap or an incorrect switch position indication. When the winding is open-circuited, the turns ratio cannot be measured or the result is abnormal. It also verifies the function of the tap changer; by measuring the turns ratio of all tap positions, it verifies that the tap changer connects correctly at each tap and achieves the expected voltage change.

[0058] The on-load tap changer measurement module 6 includes four interfaces: A, B, C, and O. When inspecting the on-load tap changer of a transformer, the inspector can connect the four interfaces of the on-load tap changer measurement module 6 (A, B, C, and O) to the four interfaces of the transformer (A, B, C, and O) respectively through wiring to measure the on-load tap changer of the transformer. The measurement results are displayed on the display screen 12.

[0059] On-load tap changer (OTC) measurement can measure the resistance value of the transition resistor in the switch to check for burnout and excessive resistance. Measuring the waveform of the circuit resistance change over time during switch switching is one of the most effective means of assessing the mechanical and electrical condition of the OLTC. The DRM waveform clearly reflects the contact quality, degree of erosion, contact duration, bounce, and jamming of the main contacts and transition contacts. Abnormal waveforms directly indicate contact wear, poor contact, or mechanical failure, such as steps, burrs, missing or deformed platforms, or excessively long / short contact times. By measuring the resistance value, it can be determined whether the circuit is burnt out or the resistance change is too large, confirming whether the switch completes the switching according to the designed timing and logic, and identifying dangerous conditions such as bridging and open circuits. DRM and operating time tests can detect problems in the energy storage mechanism, transmission mechanism, and motor drive mechanism. The on-load tap changer is the most faulty moving part of the transformer. Regularly measuring its dynamic characteristics is a key basis for predicting its remaining life and arranging preventive maintenance, effectively avoiding power outages or even equipment damage caused by sudden failures during operation.

[0060] The interface 7 includes USBM1, USBM2, USBD, RS232, SD and PLJ45 interfaces. Measurement personnel can connect external devices through each interface 7 to transmit the device's test information to the outside.

[0061] Regularly measuring the aforementioned functional structures of a transformer using equipment allows for the early detection of potential faults. Subtle changes, such as increased DC resistance imbalance, short-circuit impedance changes, minor turns ratio deviations, and abnormal on-load tap changer waveforms, can be detected before a fault develops into a severe condition leading to overheating, discharge, or even breakdown. This provides valuable time for timely intervention and maintenance, preventing equipment damage and unexpected power outages. It also enables the assessment of equipment health by comparing current measurement results with factory values, acceptance values, historical data, and standard / procedural allowable values, providing a comprehensive evaluation of the current condition of key components such as transformer windings, core, and tap changers. Furthermore, it informs maintenance decisions, as test results are the core basis for developing scientific, economical, and efficient maintenance strategies. This facilitates condition-based maintenance, avoiding over- or under-maintenance. It extends equipment life by promptly detecting and addressing issues such as loose connections, minor contact erosion, and early winding deformation, preventing these defects from worsening over long-term operation and significantly extending the transformer's lifespan. Finally, it ensures the safety and stability of the power grid, as transformers are core equipment in the grid. Ensuring that the transformer's parameters are correct, that it can withstand short-circuit current, that its connections are reliable, and that its voltage regulation function is normal are fundamental guarantees for maintaining system voltage stability, ensuring the correct operation of protection devices, and preventing the escalation of faults. Regular measurements significantly reduce the risk of the transformer itself becoming a source of power grid faults; verifying the effectiveness of maintenance, after transformer overhauls, tap changer replacements, or winding defect repairs, these measurements are necessary steps to verify whether the maintenance work was up to standard and whether the equipment has returned to a healthy state.

[0062] The end of the end 83 is provided with a plurality of mounting grooves 84. A fixed connector 85 connected to the branch line 10 is fixedly connected in the mounting groove 84. A sliding connector 87 sleeved on the fixed connector 85 is slidably connected in the mounting groove 84. An arc-shaped groove is provided on the snap-fit ​​groove 810. The end of the sliding connector 87 is hemispherical. A first spring 86 is sleeved on the fixed connector 85. The first spring 86 is pre-compressed, that is, one end of the first spring 86 abuts against the inner wall of the mounting groove 84 and the other end abuts against the end of the sliding connector 87.

[0063] As can be seen from the above, the user drives the end 83 and the sliding connector 87 to rotate through the first positioning ring 81, thereby changing the sliding connector 87 which is electrically connected to the plug rod 89 through the mounting groove 84. The first spring 86 will apply an outward pushing force to the sliding connector 87, so that the sliding connector 87 is securely abutted in the mounting groove 84. When the sliding connector 87 rotates, the mounting groove 84 will push the sliding connector 87 to compress the first spring 86, thereby causing the sliding connector 87 to disengage from the mounting groove 84. When the sliding connector 87 rotates to another mounting groove 84 position, the compressed first spring 86 returns to its original position and pushes the sliding connector 87 outward, so that the sliding connector 87 is re-engaged in the mounting groove 84.

[0064] The first positioning ring 81 has a first positioning groove 82 on its outer wall. The positioner includes a rotating cylinder 811 sleeved on the outside of the first positioning ring 81, a positioning rod 812 fixedly installed on the inner wall of the rotating cylinder 811, and a second positioning ring 813 fixedly installed on the sleeve block 88. The second positioning ring 813 has a second positioning groove 814. The positioning rod 812 is slidably engaged in the first positioning groove 82 and the second positioning groove 814. The positioning rod 812 is configured to remain engaged with the first positioning groove 82 after sliding away from the second positioning groove 814. A second spring 815 is sleeved on the sleeve block 88. One end of the second spring 815 abuts against the inner wall of the rotating cylinder 811, and the other end abuts against the second positioning ring 813.

[0065] As can be seen from the above, when the second spring 815 is not subjected to external force from the operator and remains in a partially compressed state, the positioning rod 812 is inserted into the first positioning groove 82 and the second positioning groove 814. At this time, the first positioning ring 81 and the second positioning ring 813 cannot rotate relative to each other, and the end 83 cannot rotate with the sleeve block 88. The sliding connector 87 can be stably inserted into the mounting groove 84. When the user needs to replace the sliding connector 87 that is electrically connected to the insertion rod 89 through the mounting groove 84, the user can slide the rotating cylinder 811 to compress the second spring 815, causing the positioning rod 812 to slide out of the first positioning groove 82 and the second positioning groove 814. With the second positioning groove 814 in place, the rotating drum 811 can be rotated. The rotating drum 811 drives the first positioning ring 81 and the bus 9 to rotate via the positioning rod 812 and the first positioning groove 82, thereby driving the end head 83 and the sliding connector 87 to rotate. The sliding connector 87, which is connected to the mounting groove 84 at the end of the plug rod 89, is replaced, and the branch line 10 connected to the test device is replaced. After the circuit connection of the branch line 10 is re-established, the rotating drum 811 is released, and the compressed second spring 815 returns to its original position and extends, causing the rotating drum 811 to move axially, so that the positioning rod 812 is re-inserted into the second positioning groove 814.

[0066] All standard parts used in this invention can be purchased from the market, and irregularly shaped parts can be customized according to the description and drawings. The specific connection methods for each part all employ conventional methods such as bolts, rivets, and welding, which are mature technologies in the prior art. The machinery, parts, and equipment all use conventional models in the prior art, and the circuit connections also use conventional connection methods in the prior art, which will not be detailed here. Any content not described in detail in this specification belongs to the prior art known to those skilled in the art.

[0067] The accompanying drawings of the embodiments disclosed in this utility model only involve the structures involved in the embodiments disclosed in this utility model. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this utility model can be combined with each other.

Claims

1. A comprehensive testing device for conventional transformer testing, characterized in that, include: Box body (1), on which a box cover (2) is fixedly connected; The functional modules are located inside the enclosure (1), including a short-circuit impedance test module (3), a DC resistance measurement module (4), a turns ratio group measurement module (5), and an on-load tap changer measurement module (6). A connector (7) is provided on the housing (1); A main interface (11) is provided on the housing (1) and connected to the functional module, and a switching connector (8) is plugged into the main interface (11); The display screen (12) is connected to the housing (1) and electrically connected to the functional module and the interface (7); A grounding hole (13) is provided on the enclosure (1).

2. The comprehensive testing device for conventional transformer testing according to claim 1, characterized in that: The short-circuit impedance test module (3) includes three voltage interfaces Ua, Ub, and Uc, and three current interfaces Ia, Ib, and Ic.

3. The comprehensive testing device for conventional transformer testing according to claim 1, characterized in that: The DC resistance measurement module (4) is divided into a high-voltage DC resistance measurement submodule and a low-voltage DC resistance measurement submodule. The high-voltage DC resistance measurement submodule includes four voltage interfaces U. A U B U C U O It also includes four current interface I A I B I C I O The low-voltage DC resistance measurement submodule includes four voltage interfaces U. a U b U c U o It also includes four current interface I A I B I C I o .

4. The comprehensive testing device for conventional transformer testing according to claim 1, characterized in that: The ratio group measurement module (5) includes two sets of interfaces, one set including three interfaces A, B and C, and the other set including three interfaces a, b and c.

5. The comprehensive testing device for conventional transformer testing according to claim 1, characterized in that: The on-load tap changer measurement module (6) includes four interfaces: A, B, C, and O.

6. The comprehensive testing device for conventional transformer testing according to claim 1, characterized in that: The interface (7) includes USBM1, USBM2, USBD, RS232, SD and PLJ45 interfaces.

7. The comprehensive testing device for conventional transformer testing according to claim 1, characterized in that: The switching connector (8) includes a first positioning ring (81), an end (83) fixedly installed at the end of the first positioning ring (81), and a plurality of sliding connectors (87) connected to the end (83). A sleeve (88) is rotatably connected to the end (83), and a plug rod (89) is fixedly connected to the end of the sleeve (88). A plurality of snap-fit ​​grooves (810) that snap into the sliding connectors (87) are fixedly connected to the inner wall of the sleeve (88). One snap-fit ​​groove (810) is connected to the plug rod (89). A bus (9) is connected to the first positioning ring (81), and a plurality of branch lines (10) are fixedly connected to the bus (9). The plurality of branch lines (10) correspond one-to-one with the plurality of sliding connectors (87).

8. The comprehensive testing device for conventional transformer testing according to claim 7, characterized in that: The end of the end (83) is provided with a plurality of mounting grooves (84), a fixed connector (85) connected to the branch line (10) is fixedly connected in the mounting groove (84), a sliding connector (87) sleeved on the fixed connector (85) is slidably connected in the mounting groove (84), an arc-shaped groove is provided on the snap-fit ​​groove (810), and the end of the sliding connector (87) is hemispherical.

9. The comprehensive testing device for conventional transformer testing according to claim 8, characterized in that: A first spring (86) is sleeved on the fixed connector (85). The first spring (86) is pre-compressed, that is, one end of the first spring (86) abuts against the inner wall of the mounting groove (84) and the other end abuts against the end of the sliding connector (87).

10. The comprehensive testing device for conventional transformer testing according to claim 7, characterized in that: Positioners are provided on the first positioning ring (81) and the sleeve (88). The outer wall of the first positioning ring (81) is provided with a first positioning groove (82). The positioner includes a rotating cylinder (811) sleeved on the outside of the first positioning ring (81), a positioning rod (812) fixedly installed on the inner wall of the rotating cylinder (811), and a second positioning ring (813) fixedly installed on the sleeve (88). The second positioning ring (813) is provided with a second positioning groove (814). The positioning rod (812) is slidably engaged in the first positioning groove (82) and the second positioning groove (814). The positioning rod (812) is configured to remain engaged with the first positioning groove (82) after sliding away from the second positioning groove (814). A second spring (815) is sleeved on the sleeve (88). One end of the second spring (815) abuts against the inner wall of the rotating cylinder (811), and the other end abuts against the second positioning ring (813).

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