Transformer testing device and testing method

Abstract

The invention relates to the technical field of transformer testing, and discloses a transformer testing device and method, and the device comprises a device housing which is internally provided with an axial through hollow cavity; the testing cylinder is coaxially fixed in the hollow cavity of the device shell, and the outer surface of the testing cylinder is used for winding a winding coil to be tested; the main shaft is arranged in a penetrating mode in the axis direction of the testing cylinder, and the two ends of the main shaft extend out of the device shell; the at least three groups of secondary shafts are uniformly distributed around the main shaft in the circumferential direction; the linkage mechanism is arranged between the main shaft and the secondary shaft and used for converting the axis spinning motion of the main shaft into the radial expansion motion of the secondary shaft; according to the scheme, axial compression force and radial expansion force can be synchronously or independently applied through the main shaft and secondary shaft linkage mechanism, compared with a traditional device which can only apply force in one direction and accurately simulate the multidirectional electromagnetic force coupling effect borne by a winding coil when the transformer is short-circuited, the test result is closer to the actual working condition.

Description

Technical Field

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

[0002] As the core equipment of the power system, the reliability of the transformer directly affects the stable operation of the power grid. The winding is the "heart" of the transformer and undertakes the key task of electromagnetic energy conversion.

[0003] During operation, if a short circuit occurs in the winding, the instantaneous current in the winding can reach dozens of times the rated value, generating huge electromagnetic forces (axial compression force and radial expansion force), which may cause winding deformation, insulation damage, or even structural disintegration. Therefore, there is an urgent need for a transformer testing device to perform mechanical strength testing on the windings during the production stage to avoid failure of the windings in this batch. Summary of the Invention

[0004] The purpose of the present invention is to provide a transformer testing device and a testing method, aiming to solve the problems in the prior art.

[0005] The present invention is implemented as follows: a transformer testing device comprising: The device housing has an axially penetrating hollow cavity provided therein; A test cylinder is coaxially fixed in the hollow cavity of the device housing, and the outer surface of the test cylinder is used for winding the winding coil to be tested; A main shaft is provided along the axis of the test cylinder and has two ends extending to the outside of the device housing; at least three sets of secondary axes, uniformly distributed circumferentially around the primary axis; A linkage mechanism is provided between the main shaft and the secondary shaft, and is used to convert the axial rotation motion of the main shaft into the radial expansion motion of the secondary shaft; The support block is installed in the middle of each secondary shaft. The distance between it and the secondary shaft axis can be adjusted, and it applies radial expansion force to the inner wall of the winding coil as the secondary shaft expands radially; The pressure-extracting machine is fixed to the outer end of the device housing, and its output end is used to drive the main shaft to move axially, and simultaneously drive the support block to apply axial compression force to the end face of the winding coil along the axial direction.

[0006] Preferably, a first support tube and a second support tube are respectively provided at both ends of the main shaft, an expansion motor is fixedly mounted on the inner wall of the second support tube, an output shaft of the expansion motor is connected to the end of the main shaft, and the other end of the main shaft is connected to the internal bearing of the first support tube; A switching motor is fixedly mounted on the inner wall of the first support tube, an eccentric connecting piece is sleeved on the output shaft of the switching motor, and a pressing motor is mounted on the end of the eccentric connecting piece away from the switching motor.

[0007] Preferably, the linkage mechanism comprises a connecting ring sleeved on the outside of both ends of the main shaft, and the first diagonal support rods corresponding to the secondary shaft are evenly distributed and connected around the connecting ring through the rotating shaft; The ends of the first diagonal bracing rods at both ends of the main shaft are distributed toward each other and are respectively connected to fixing rings through rotating shafts, and the secondary shaft is fixed by bolts of the fixing rings.

[0008] Preferably, the surfaces of both ends of the main shaft are respectively provided with forward threads and reverse threads, and the inner walls of the connecting rings at both ends are respectively provided with thread grooves that engage with the forward threads and reverse threads.

[0009] Preferably, the internal bearing of the secondary shaft is connected to a rotating rod, the end of the rotating rod passes through and extends into the interior of the first support tube and is sleeved with a transmission gear; The output shaft of the pressing motor is sleeved with a driving gear meshed with the transmission gear.

[0010] Preferably, connecting blocks are sleeved on both sides of the middle of the rotating rod, and the second oblique support rods are connected between the two connecting blocks through a rotating shaft, and the supporting and pressing blocks are connected through the rotating shafts of the two second oblique support rods.

[0011] Preferably, the surfaces of both ends of the rotating rod are respectively provided with forward threads and reverse threads, and the inner walls of the connecting blocks at both ends are respectively provided with thread grooves engaged with the forward threads and reverse threads.

[0012] Preferably, it further comprises a gland, which is fixed to one side of the device housing, the inner wall of the device housing is provided with two first clamping plates, and one side of the gland is provided with a second clamping plate corresponding to the first clamping plates; The upper and lower surfaces of the test cylinder are respectively provided with two sets of clamping rings corresponding to the first clamping plate and the second clamping plate.

[0013] Preferably, the surface of the test cylinder is evenly distributed with guide grooves corresponding to the support and pressure blocks, and the length of the guide grooves is greater than the length of the winding coil; The supporting and pressing block moves inside and outside the testing cylinder through the guide groove.

[0014] A transformer testing method, applied to the aforementioned transformer testing device, is characterized by: S1. Wind the winding coil to be tested on the outer surface of the test tube and fix it inside the device housing; S2. When the inner wall of the winding coil needs to be tested for expansion force mechanical strength, the corresponding support block is adjusted to move in a direction away from the secondary axis according to the preset position where the radial expansion force needs to be applied to the inner wall of the winding coil; S3. The driving main shaft pushes the surrounding secondary shafts to expand radially through the linkage mechanism, so that the support and pressure blocks act on the inner wall of the winding coil. The main shaft's axial rotation angle is continuously increased, so that the support and pressure blocks apply increasing radial expansion force to the inner wall of the winding, completing the radial expansion force test operation. S4. When it is necessary to perform an axial compressive force mechanical strength test on the end face of the winding coil, adjust the support block to move in the direction close to the secondary axis; S5. The telescopic part of the pressure-applying telescopic machine pushes the support block to be placed outside the end of the winding coil. According to the preset position where the axial compressive force is required to be applied to the end face of the winding coil, the corresponding support block is adjusted to move in a direction away from the secondary axis so that the support block is placed on the end face of the winding coil; S6. Drive the telescopic part of the pressure-applying telescopic machine to push the supporting block along the axial direction, apply increasing axial compressive force to the end face of the winding, and complete the axial compressive force detection operation.

[0015] The present invention discloses a transformer testing device and testing method, the beneficial effects of which are: this scheme can synchronously or independently apply axial compression force and radial expansion force through the main shaft and secondary shaft linkage mechanism. Compared with traditional devices that can only apply force in one direction, this scheme accurately simulates the multi-directional electromagnetic force coupling effect that the winding coil is subjected to when the transformer is short-circuited, and the test results are closer to actual working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1 is a schematic diagram of a transformer testing device provided by an embodiment of the present invention; Figure 2 This is a partial structural diagram of a transformer testing device provided by an embodiment of the present invention; Figure 3 A transformer testing device provided by an embodiment of the present invention Figure 2 A partial cross-sectional view of the part; Figure 4 A transformer testing device provided by an embodiment of the present invention Figure 2 A partial cross-sectional view at point B in FIG. Figure 5 A transformer testing device provided by an embodiment of the present invention Figure 2 Schematic diagram of the internal local structure.

[0017] Marking Description: 1. Device housing; 2. Gland; 3. Test tube; 4. Pressure expansion mechanism; 5. Winding coil; 11. First pallet; 21. Second pallet; 31. First support tube; 32. Second support tube; 33. Snap ring; 34. Guide groove; 35. Main shaft; 36. Connecting ring; 37. First diagonal support rod; 38. Fixed ring; 39. Secondary shaft; 311, switching motor; 312, eccentric connecting piece; 313, pressing motor; 314, driving gear; 321, expansion motor; 391. Rotating rod; 392. Transmission gear; 393. Connecting block; 394. Second diagonal support rod; 395. Support and pressure block. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "up", "down", "left", "right", etc. indicate directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0020] The implementation of the present invention is described in detail below with reference to specific embodiments.

[0021] This solution aims to solve the problem that when a short circuit occurs in the winding during transformer operation, the instantaneous current in the winding can reach dozens of times the rated value, generating huge electromagnetic forces (axial compression and radial expansion), which may cause winding deformation, insulation damage, and even structural disintegration. Therefore, a transformer testing device is provided to perform mechanical strength testing on the windings during the production stage to avoid the problem of unqualified windings in the batch. In this embodiment: Reference Figure 1-Figure 2 As shown, a preferred embodiment of the present invention is provided.

[0022] A transformer testing device according to this embodiment includes: The device housing 1 has an axially penetrating hollow cavity inside; A test cylinder 3 is coaxially fixed in the hollow cavity of the device housing 1, and the outer surface of the test cylinder 3 is used for winding the winding coil 5 to be tested; The main shaft 35 is provided along the axis direction of the test cylinder 3 and has both ends extending to the outside of the device housing 1; At least three groups of secondary shafts 39 are evenly distributed around the primary shaft 35 in the circumferential direction; A linkage mechanism is provided between the main shaft 35 and the secondary shaft 39 and is used to convert the axial rotation motion of the main shaft 35 into the radial expansion motion of the secondary shaft 39; The support block 395 is installed in the middle of each secondary shaft 39. The distance between the support block and the axis of the secondary shaft 39 can be adjusted, and the support block 395 exerts a radial expansion force on the inner wall of the winding coil 5 as the secondary shaft 39 expands radially. The pressure-applying telescopic machine 4 is fixed to the outer side of the end of the device housing 1, and its output end is used to drive the main shaft 35 to move axially, and simultaneously drive the supporting block 395 to apply axial compression force to the end face of the winding coil 5 along the axial direction.

[0023] Among them, refer to the attached Figure 3-Figure 4 As shown, the two ends of the main shaft 35 are respectively provided with a first support tube 31 and a second support tube 32. The telescopic portion of the pressure-applying telescopic machine 4 is connected to the second support tube 32. An expansion motor 321 is fixedly mounted on the inner wall of the second support tube 32. The output shaft of the expansion motor 321 is connected to the end of the main shaft 35, and the other end of the main shaft 35 is connected to the internal bearing of the first support tube 31. A switching motor 311 is fixedly mounted on the inner wall of the first support tube 31. The output shaft of the switching motor 311 is sleeved with an eccentric connecting piece 312. The end of the eccentric connecting piece 312 away from the switching motor 311 is equipped with a pressing motor 313. The linkage mechanism includes a connecting ring 36 sleeved on the outside of the two ends of the main shaft 35, and the first diagonal support rods 37 corresponding to the secondary shaft 39 are evenly distributed around the connecting ring 36 through the rotating shaft. The ends of the first diagonal support rods 37 located at the two ends of the main shaft 35 are distributed facing each other and are respectively connected to the fixing rings 38 through the rotating shaft. The secondary shaft 39 is fixed by the fixing rings 38 bolts. The two end surfaces of the main shaft 35 are respectively provided with forward threads and reverse threads, and the inner walls of the connecting rings 36 at both ends are respectively provided with thread grooves that engage with the forward threads and reverse threads. When the expansion motor 321 drives the main shaft 35 to rotate along the axis, the two groups of connecting rings 36 at both ends are connected by the forward threads and reverse threads to realize reverse synchronous transmission, and then push the fixing rings 38 through the first diagonal support rods 37 to push and drive the secondary shaft 39 to complete the retraction and expansion operation.

[0024] Further, see the attached Figure 5As shown, the internal bearing of the secondary shaft 39 is connected to a rotating rod 391, the end of the rotating rod 391 passes through and extends to the interior of the first support tube 31, and is sleeved with a transmission gear 392; the output shaft of the pressing motor 313 is sleeved with a driving gear 314 that meshes with the transmission gear 392; connecting blocks 393 are sleeved on both sides of the middle of the rotating rod 391, and a second diagonal support rod 394 is connected between the two connecting blocks 393 through a rotating shaft, and the supporting block 395 is connected by the rotating shaft of the two second diagonal support rods 394; the surfaces of both ends of the rotating rod 391 are respectively provided with forward and reverse threads, and the inner walls of the connecting blocks 393 at both ends are respectively opened. A thread groove is provided for engaging with the forward and reverse threads. When the distance between the support and pressure block 395 and the axis of the secondary shaft 39 needs to be adjusted, the output shaft of the switching motor 311 drives the pressure motor 313 at the end of the eccentric connecting piece 312 to rotate, so that the driving gear 314 of the output shaft of the pressure motor 313 engages with the transmission gear 392 at the end of the rotating rod 391. Then, the pressure motor 313 drives the rotating rod 391 to rotate, so that the rotating rod 391 realizes reverse synchronous transmission through the two sets of connecting blocks 393 connected by the forward and reverse threads at both ends of the rotating rod 391. Then, the second oblique support rod 394 pushes the support and pressure block 395 to realize the telescopic operation in and out of the test tube 3. It is worth noting that the rotating rod 391 has an anti-backward structure to prevent the driving gear 314 from accidentally pushing the rotating rod 391 through the transmission gear 392 to rotate during the switching process of the switching motor 311 to the pressing motor 313.

[0025] In the attached Figure 1 In the embodiment, the present application further includes a gland 2, which is clamped and fixed to one side of the device housing 1, and the inner wall of the device housing 1 is provided with two first clamping plates 11, and one side of the gland 2 is provided with a second clamping plate 21 corresponding to the first clamping plate 11, and the upper and lower surfaces of the test cylinder 3 are respectively provided with two groups of clamping rings 33 corresponding to the first clamping plate 11 and the second clamping plate 21, and the two ends of the winding coil 5 are limited between the two groups of clamping rings 33, and the surface of the test cylinder 3 is evenly distributed with guide grooves 34 corresponding to the support and pressure blocks 395, and the length of the guide grooves 34 is greater than the length of the winding coil 5. At the same time, the clamping ring 33 is disconnected at the guide groove 34, and the support and pressure block 395 moves inside and outside the test cylinder 3 through the guide groove 34, so that the support and pressure block 395 can pass through the clamping ring 33 to apply pressure to the end of the winding coil 5; In this embodiment, the contact points between the supporting and pressing block 395 and the inner wall of the winding coil 5 and the contact points between the ends of the winding coil 5 are integrated with pressure sensors to provide real-time feedback on the magnitude of the applied force.

[0026] The present embodiment also includes a transformer testing method, in which the winding coil 5 to be tested is wound on the outer surface of the test tube 3 and fixed inside the device housing 1; when it is necessary to perform an expansion force mechanical strength test on the inner wall of the winding coil 5, the corresponding support and pressure block 395 is adjusted to move in a direction away from the secondary shaft 39 according to the preset position where the radial expansion force is required to be applied to the inner wall of the winding coil 5; the main shaft 35 is driven to push the surrounding secondary shafts 39 to radially expand through the linkage mechanism, so that the support and pressure block 395 acts on the inner wall of the winding coil 5, and the axial rotation angle of the main shaft 35 is continuously increased, so that the support and pressure block 395 applies an increasing radial expansion force to the inner wall of the winding, thereby completing the test. Perform radial expansion force test operation; when it is necessary to perform axial compression force mechanical strength test on the end face of the winding coil 5, adjust the support block 395 to move in the direction close to the secondary axis 39; the telescopic part of the pressure-applying telescopic machine 4 pushes the support block 395 to be placed on the outside of the end of the winding coil 5, and according to the preset position where the axial compression force needs to be applied to the end face of the winding coil 5, adjust the corresponding support block 395 to move in the direction away from the secondary axis 39, so that the support block 395 is placed on the end face of the winding coil 5; drive the telescopic part of the pressure-applying telescopic machine 4 to push the support block 395 along the axial direction, apply increasing axial compression force to the end face of the winding, and complete the axial compression force detection operation.

[0027] This solution uses the linkage mechanism between the main shaft 35 and the secondary shaft 39 to synchronously or independently apply axial compression force and radial expansion force. Compared with traditional devices that can only apply force in one direction, it accurately simulates the multi-directional electromagnetic force coupling effect that the winding coil 5 is subjected to when the transformer is short-circuited, and the test results are closer to actual working conditions.

[0028] On the basis of the above embodiment, the above pressure telescopic machine 4 can be a pneumatic cylinder, an oil cylinder, a motor with a lifting rod, etc., which is not limited in this embodiment.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A transformer testing device, characterized in that: include: A device housing (1) is provided with an axially penetrating hollow cavity therein; A test cylinder (3) is coaxially fixed in the hollow cavity of the device housing (1), and the outer surface of the test cylinder (3) is used for winding the winding coil (5) to be tested; A main shaft (35) is provided along the axial direction of the test cylinder (3), and both ends extend to the outside of the device housing (1); At least three groups of secondary axes (39) are evenly distributed around the primary axis (35); A linkage mechanism is provided between the main shaft (35) and the secondary shaft (39), and is used to convert the axial rotation motion of the main shaft (35) into the radial expansion motion of the secondary shaft (39); A support block (395) is installed in the middle of each secondary shaft (39), and can adjust the distance between the support block and the axis of the secondary shaft (39), and exerts a radial expansion force on the inner wall of the winding coil (5) as the secondary shaft (39) expands radially; The pressure-applying telescopic machine (4) is fixed to the outer side of the end of the device housing (1), and its output end is used to drive the main shaft (35) to move axially and simultaneously drive the support and pressure block (395) to apply axial compression force to the end face of the winding coil (5) along the axial direction.

2. A transformer testing device according to claim 1, characterized in that: The two ends of the main shaft (35) are respectively provided with a first support tube (31) and a second support tube (32); an expansion motor (321) is fixedly mounted on the inner wall of the second support tube (32); the output shaft of the expansion motor (321) is connected to the end of the main shaft (35); and the other end of the main shaft (35) is connected to the internal bearing of the first support tube (31); A switching motor (311) is fixedly mounted on the inner wall of the first support tube (31), an eccentric connecting piece (312) is sleeved on the output shaft of the switching motor (311), and a pressing motor (313) is mounted on one end of the eccentric connecting piece (312) away from the switching motor (311).

3. A transformer testing device according to claim 2, characterized in that: The linkage mechanism comprises a connecting ring (36) sleeved on the outside of both ends of the main shaft (35), and the connecting ring (36) is evenly connected to first diagonal support rods (37) corresponding to the secondary shaft (39) via rotating shafts. The ends of the first diagonal support rods (37) located at both ends of the main shaft (35) are distributed toward each other and are respectively connected to fixing rings (38) via rotating shafts. The secondary shaft (39) is fixed by bolts via the fixing rings (38).

4. A transformer testing device according to claim 3, characterized in that: The surfaces of both ends of the main shaft (35) are respectively provided with forward threads and reverse threads, and the inner walls of the connecting rings (36) at both ends are respectively provided with thread grooves that engage with the forward threads and reverse threads.

5. A transformer testing device according to claim 2, characterized in that: The internal bearing of the secondary shaft (39) is connected to a rotating rod (391), the end of the rotating rod (391) passes through and extends into the interior of the first support tube (31), and is sleeved with a transmission gear (392); The output shaft of the pressing motor (313) is sleeved with a driving gear (314) that meshes with the transmission gear (392).

6. A transformer testing device according to claim 5, characterized in that: Connecting blocks (393) are sleeved on both sides of the middle of the rotating rod (391), and a second diagonal support rod (394) is connected between the two connecting blocks (393) via a rotating shaft. The supporting block (395) is connected via the rotating shaft of the two second diagonal support rods (394).

7. A transformer testing device according to claim 6, characterized in that: The surfaces of both ends of the rotating rod (391) are respectively provided with forward threads and reverse threads, and the inner walls of the connecting blocks (393) at both ends are respectively provided with thread grooves that engage with the forward threads and reverse threads.

8. A transformer testing device according to claim 1, characterized in that: It also includes a pressure cover (2), the pressure cover (2) being fixedly connected to one side of the device housing (1), the inner wall of the device housing (1) being provided with two first clamping plates (11), and one side of the pressure cover (2) being provided with a second clamping plate (21) corresponding to the first clamping plates (11); The upper and lower surfaces of the test cylinder (3) are respectively provided with two groups of clamping rings (33) corresponding to the first clamping plate (11) and the second clamping plate (21).

9. A transformer testing device according to claim 1, characterized in that: The surface of the test cylinder (3) is evenly distributed with guide grooves (34) corresponding to the support and pressure blocks (395), and the length of the guide grooves (34) is greater than the length of the winding coil (5); The supporting and pressing block (395) moves inside and outside the test cylinder (3) through the guide groove (34).

10. A transformer testing method, applied to a transformer testing device according to any one of claims 1 to 9, characterized in that: S1. Winding the winding coil (5) to be tested on the outer surface of the test tube (3) and fixing it inside the device housing (1); S2. When it is necessary to perform an expansion force mechanical strength test on the inner wall of the winding coil (5), the corresponding support block (395) is adjusted to move in a direction away from the secondary axis (39) according to the preset position where the radial expansion force is required to be applied to the inner wall of the winding coil (5); S3, driving the main shaft (35) to push the surrounding secondary shafts (39) to radially expand through the linkage mechanism, so that the support and pressure blocks (395) act on the inner wall of the winding coil (5), and continuously increasing the axial rotation angle of the main shaft (35), so that the support and pressure blocks (395) apply increasing radial expansion force to the inner wall of the winding, completing the radial expansion force test operation; S4. When it is necessary to perform an axial compressive force mechanical strength test on the end face of the winding coil (5), the support and pressure block (395) is adjusted to move in a direction close to the secondary axis (39); S5, the telescopic part of the pressure-applying telescopic machine (4) pushes the supporting block (395) to be placed outside the end of the winding coil (5), and adjusts the corresponding supporting block (395) to move in a direction away from the secondary axis (39) according to the preset position of the end face of the winding coil (5) where the axial compressive force is required to be applied, so that the supporting block (395) is placed on the end face of the winding coil (5); S6. Drive the telescopic portion of the pressure-applying telescopic machine (4) to push the supporting block (395) along the axial direction, apply an increasing axial compressive force to the end face of the winding, and complete the axial compressive force detection operation.

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