Anti-short-circuit dry-type transformer

Abstract

The utility model relates to the field of general parts of transformers, in particular to an anti-short-circuit dry-type transformer. The anti-short-circuit dry-type transformer is used for solving the problems that when an existing dry-type transformer is short-circuited, dislocation and movement of a high-voltage coil cannot be effectively prevented, and the dry-type transformer is prone to being damaged. The anti-short-circuit dry-type transformer comprises an upper clamping piece, a lower clamping piece and a three-phase winding located between the upper clamping piece and the lower clamping piece, insulating cushion blocks are arranged between the upper clamping piece and the winding and between the lower clamping piece and the winding, and a supporting block which is used for being tightly supported between a high-voltage coil and a low-voltage coil of the winding to avoid dislocation and movement of the high-voltage coil is arranged close to the insulating cushion blocks and between the high-voltage coil and the low-voltage coil. A groove is formed in the end, close to the supporting block, of the insulating cushion block, the supporting block is provided with a protruding part which can stretch into the groove and is matched with the groove in shape, and the side, back on to the protruding part, of the supporting block is tightly supported between the high-voltage coil and the low-voltage coil to form a tight supporting part. And by arranging the supporting blocks, deformation of the high-voltage coil during short circuit is avoided, and the service life of the dry-type transformer is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to the general spare part field of transformer, concretely relates to anti short circuit dry type transformer. BACKGROUND

[0002] Transformer is the primary electrical equipment commonly used in power system, it mainly uses transformation voltage. But in power system operation, short circuit fault is difficult to avoid absolutely. When short circuit occurs, the high voltage coil and low voltage coil of winding are subjected to electromagnetic force and can produce transverse and radial misplacement, which can cause serious damage to dry type transformer. Therefore, the existing dry type transformer is usually provided with anti short circuit structure to avoid misplacement of coil.

[0003] The utility model discloses a dry type grounding transformer outlet terminal insulation device, the transformer includes upper clamp piece, lower clamp piece and the three-phase winding of setting between upper clamp piece and lower clamp piece, is provided with the cushion block between upper clamp piece and lower clamp piece and three-phase winding, the cushion block is usually fixed and press -fitted in the upper and lower two ends of winding through the press nail of setting on upper clamp piece and lower clamp piece, and the cushion block can press tightly winding in the upper and lower directions, and this structure can prevent the axial misplacement of coil, but can not effectively prevent the radial misplacement of coil, and when serious, can cause the deformation of winding and further cause the damage of dry type transformer. SUMMARY

[0004] The utility model provides a kind of anti short circuit dry type transformer to solve the problem that the radial misplacement of coil cannot be effectively prevented when the existing dry type transformer short circuits, causes dry type transformer damage.

[0005] The utility model discloses an anti short circuit dry type transformer adopts the following technical scheme:

[0006] Anti short circuit dry type transformer includes upper clamp piece, lower clamp piece and the three-phase winding between upper clamp piece and lower clamp piece, and the insulating cushion block between upper clamp piece and lower clamp piece and every phase winding is provided with, and the support block for being used to be tightly in between high voltage coil and low voltage coil between the insulating cushion block, high voltage coil and low voltage coil is set to avoid the misplacement of high voltage coil, and the end of insulating cushion block close to support block is provided with recess, and support block has the protruding portion that can be inserted into recess and with recess shape adaptation, and the side of support block away from protruding portion is tightly between high voltage coil and low voltage coil to constitute support tight portion.

[0007] Further, support tight portion end is provided with the avoidance installation slot for the insulating cylinder between high voltage coil and low voltage coil to pass in.

[0008] Further, the support tight portion of the support block is arc plate, and the inner side arc surface is adapted to the shape of low voltage coil outer ring, and the outer side arc surface is adapted to the shape of high voltage coil inner ring.

[0009] Further, the supporting block is a silica gel supporting block.

[0010] Further, the insulating pad is provided with a group of pressing pin fixing grooves, and the upper and lower clamping members are provided with corresponding pressing pins to fix the insulating pad.

[0011] Further, the pressing pin is sleeved with a metal gasket to be sealed with the pressing pin fixing groove during installation.

[0012] Further, at least one of the upper and lower clamping members comprises a bent plate with a vertical plate and a horizontal plate, and the horizontal plate is provided with a cantilever plate corresponding to the position of the insulating pad, and the pressing pin fixing hole of the pressing pin is arranged on the cantilever plate.

[0013] Further, a reinforcing inclined brace is arranged between the vertical plate and the cantilever plate.

[0014] Further, the insulating pad is provided with an umbrella skirt on the side facing the high-voltage coil to increase the creepage distance of the surface of the insulating pad.

[0015] Further, a supporting member is arranged between the low-voltage coil and the iron core.

[0016] The utility model provides an improved technical scheme, is provided with the supporting block for supporting between high voltage coil and low voltage coil of winding to avoid the dislocation movement of high voltage coil, and the supporting block is installed with the insulating pad through the protruding portion on it to realize the positioning of supporting block. After the installation of supporting block is completed, can be supported between high voltage coil and low voltage coil to effectively prevent the radial dislocation movement of high voltage coil, avoids the deformation of high voltage coil when short circuit, improves the service life of dry-type transformer. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the front view of the short circuit resisting dry-type transformer of the utility model;

[0018] Figure 2 It is the left view of Figure 1 ;

[0019] Figure 3 It is the plan view of Figure 1 ;

[0020] Figure 4 It is the front view of insulating pad;

[0021] Figure 5 It is the side view of Figure 4 ;

[0022] Figure 6 It is the plan view of Figure 4 ;

[0023] Figure 7 It is the structural schematic view of supporting block;

[0024] Figure 8 is a front view of Figure 7 ;

[0025] Figure 9 is a side view of Figure 7 ;

[0026] Figure 10 is a plan view of Figure 7 ;

[0027] Figure 11 is a structural schematic view of the upper clamp;

[0028] Figure 12 is a structural schematic view of the lower clamp.

[0029] In the figure: 1, high voltage coil; 2, low voltage coil; 3, iron core; 4, insulating pad; 41, press pin fixing groove; 42, recess; 43, umbrella skirt; 5, support block; 51, protruding part; 52, bracing part; 53, inner arc surface; 54, avoiding installation groove; 55, outer arc surface; 6, upper clamp; 61, overhanging plate; 62, reinforcing diagonal brace; 63, press pin fixing hole; 7, lower clamp; 8, silica gel rod; 9, insulating cylinder. DETAILED DESCRIPTION

[0030] The utility model discloses an improved technical scheme for the above technical problem, and the core idea of the utility model is that a support block for bracing between the high voltage coil and the low voltage coil of the winding to avoid misplacement of the high voltage coil is arranged, and the support block is installed in position by the cooperation of the protruding part on the support block and the insulating pad. After the installation of the support block, the support block can be braced between the high voltage coil and the low voltage coil to effectively prevent the radial misplacement of the high voltage coil, avoid the deformation of the high voltage coil in short circuit, and improve the service life of the dry-type transformer.

[0031] According to the above idea, the anti-short-circuit dry-type transformer of the utility model comprises upper and lower clamps and three-phase windings between the upper and lower clamps as shown in Figure 1 , the upper clamp 6 and the lower clamp 7 are provided with insulating pads 4 between each phase winding, and the insulating pads 4 are provided with support blocks 5 for bracing between the high voltage coil 1 and the low voltage coil 2 of the winding to avoid misplacement of the high voltage coil 1 as shown in Figures 7-10 , and one end of the insulating pad 4 close to the support block 5 is provided with a protruding part 51 as shown in Figure 4 .The shown groove 42, the support block 5 has a protruding part 51 which can extend into the groove 42 and fit the shape of the groove 42, the side of the support block 5 which is away from the protruding part 51 is tightly supported between the high-voltage coil 1 and the low-voltage coil 2 to form a supporting part 52. The support block 5 is installed in cooperation with the insulating pad 4 through the protruding part 51 thereon to realize the positioning of the support block 5, which ensures that the position of the support block 5 will not be deviated. The support block 5 is tightly supported between the high-voltage coil 1 and the low-voltage coil 2, which can effectively prevent the lateral movement of the high-voltage coil 1, avoid the deformation of the high-voltage coil 1 when short-circuiting, and improve the service life of the short-circuit-resistant dry-type transformer.

[0032] In the present embodiment, the end of the supporting part 52 is provided with a avoiding installation slot 54 for the insulating cylinder 9 between the high-voltage coil 1 and the low-voltage coil 2 to pass through. In this way, one end of the support block 5 is installed in cooperation with the insulating pad 4 through the protruding part 51, and the other end of the support block is installed with the insulating cylinder 9 through the avoiding installation slot 54, which further ensures that the position of the support block 5 will not be deviated. The groove 42 of the insulating pad 4 in the present embodiment is a square slot, and at this time the insulating cylinder 9 can also support the support block 5 located on the upper side. In addition, in other embodiments, the groove of the insulating pad can be a dovetail groove, and the protruding part of the support block fits the shape of the dovetail groove to ensure that the upper support block will not fall down.

[0033] The core 3, the high-voltage coil 1 and the low-voltage coil 2 of each phase winding in the present embodiment are all in an oblong circular structure as shown in Figure 3 In this way, the center distance between each phase winding of the transformer is reduced, and the size of the transformer in the length direction is more compact. The window width of the core 3 is also narrowed. In the case of the same core 3 section and core 3 height, the core 3 silicon steel sheet used in the present embodiment is less, and the no-load loss of the whole transformer is reduced. The low-voltage coil 2 and the high-voltage coil 1 are pressed after being wound in the straight part, and are integrally cast, which avoids the vibration phenomenon of the copper foil of the low-voltage coil 2 and the high-voltage coil 1 under the action of the periodically changing magnetic field, and makes the low-voltage coil 2 and the high-voltage coil 1 form a solid whole, further improving the short-circuit resistance of the dry-type transformer, and avoiding the generation of large noise due to the vibration of the coil.

[0034] In the present embodiment, as shown in Figure 7 、 Figure 10 The supporting part 52 of the support block 5 is in the shape of a circular arc plate, the inner arc surface 53 fits the shape of the outer circle of the low-voltage coil 2, and the outer arc surface 55 fits the shape of the inner circle of the high-voltage coil 1. In this way, the contact area of the supporting part 52 of the support block 5 with the high-voltage coil 1 and the low-voltage coil 2 is ensured, and the tightness of the high-voltage coil 1 and the low-voltage coil 2 is maximized. In addition, in other embodiments, the supporting part 52 of the support block 5 can also be in the shape of a cylinder or a cuboid, as long as the support block 5 can be placed between the high-voltage coil 1 and the low-voltage coil 2 and realize the tightness of the two.

[0035] In the embodiment, the support block 5 is a silica gel support block 5. The silica gel support block 5 has certain elasticity, and has high mechanical strength while ensuring the support of the low-voltage coil 2 and the high-voltage coil 1. Meanwhile, the silica gel support block 5 also has good heat conduction performance, which is helpful for heat dissipation of the coils. In addition, in other embodiments, the support block 5 can also be a rubber support block 5, an epoxy support block 5 or other insulating support block 5.

[0036] In the embodiment, the insulating pad 4 is provided with a group of press pin fixing grooves 41, and the upper clamp 6 is provided with corresponding press pins to fix the insulating pad 4. As shown in Figure 6 , the insulating pad 4 of the embodiment is provided with two press pin fixing grooves 41, which cooperate with two press pins on the upper clamp 6, so as to ensure the reliability of the fixation of the insulating pad 4. In addition, in other embodiments, the insulating pad 4 can also be provided with three or more press pin fixing grooves 41, of course, a single press pin fixing groove 41 can also be provided, as long as the press pins on the upper clamp 6 can reliably fasten the insulating pad 4. The insulating pad 4 of the embodiment is obtained by pouring the outer part of the metal piece with a smooth circular groove inside, which ensures the structural strength of the insulating pad 4.

[0037] In the embodiment, a metal gasket is sleeved on the press pin to seal with the press pin fixing groove 41 during installation. The metal gasket of the embodiment is adapted to the shape of the press pin fixing groove 41, and after the metal gasket is sealed with the press pin fixing groove 41, a shielding cavity is formed around the space in the counterbore as a whole, so that the end of the press pin close to the coil forms a space with approximately zero magnetic field strength in the air gap in the groove 42, which can avoid the local discharge phenomenon at the insulating pad 4. In addition, in other embodiments, the press pin can also directly cooperate with the press pin fixing groove of the insulating pad to fasten the insulating pad.

[0038] In the embodiment, at least one of the upper and lower clamps includes a bent plate having a vertical plate and a horizontal plate, and a cantilever plate 61 is provided on the horizontal plate corresponding to the position of the insulating pad 4 as shown in Figure 11 , and a press pin fixing hole 63 of the press pin is arranged on the cantilever plate 61. The upper and lower clamps of the embodiment are obtained by bending a steel plate, and the upper clamp 6 of the embodiment is an L-shaped plate, as shown in Figure 11 , the horizontal plate is provided with the cantilever plate 61, which is used to position the insulating pad 4, so as to save the material of the upper clamp 6 and realize the lightweight of the upper clamp 6. The lower clamp 7 of the embodiment is as shown in Figure 2 , Figure 12As shown, the cross section is U-shaped, and the opening faces the transformer external direction, and the upper horizontal surface of the lower clamp 7 is used to connect with the insulating pad 4. In addition, in other embodiments, the upper clamp and the lower clamp can both be a vertical plate and a horizontal plate extending to the corresponding position of the insulating pad at the bottom of the vertical plate, and the pressing nail fixing hole of the pressing nail is arranged on the horizontal plate, and only the reliable fastening of the upper clamp to the insulating pad needs to be ensured.

[0039] In the embodiment, a reinforcing inclined support 62 as shown in Figure 11 、 Figure 12 is arranged between the vertical plate and the overhanging plate 61. In this way, the strength of the overhanging plate 61 can be strengthened, and the toughness and reliability of the upper and lower clamps in the case of short circuit are also increased, and the reliability of the installation of the upper clamp 6 and the insulating pad 4 is further improved.

[0040] In the embodiment, the side of the insulating pad 4 facing the high-voltage coil 1 is provided with an umbrella skirt 43 as shown in Figure 4 、 Figure 5 to increase the creepage distance of the surface of the insulating pad 4. At the same time, under the condition of the same distance, the creepage distance of the high-voltage coil 1 and the clamp is also increased. The setting of the umbrella skirt 43 makes it more difficult for the electric arc to form and maintain in a humid or contaminated environment. This helps to prevent electrical breakdown or short circuit, thereby enhancing the insulation performance of the transformer. Of course, the insulating pad can also be consistent with the side structure of the insulating pad 4 of the transformer of the authorized announcement No. CN206412192U, that is, no umbrella skirt is arranged, and the whole is block-shaped.

[0041] In the embodiment, a straining member is arranged between the low-voltage coil 2 and the iron core 3. The straining member of the embodiment is a strutting bar and a silica gel rod 8. The strutting bar and the silica gel rod 8 can effectively block the inward contraction of the low-voltage coil 2 in the case of short circuit, avoiding the deformation of the low-voltage coil 2 in the case of short circuit, and improving the service life of the dry-type transformer. In addition, in other embodiments, the straining member can also be a round stick and a strutting plate.

[0042] The above is only a preferred embodiment of the present application, and is not used to limit the present application, and the patent protection scope of the present application is subject to the claims, and any equivalent structural changes made by referring to the contents of the specification and drawings of the present application should also be included in the protection scope of the present application.

Claims

1. An anti-short-circuit dry-type transformer comprising upper and lower clamps and three-phase windings located between the upper and lower clamps, and an insulating pad provided between the upper and lower clamps and each phase winding, characterized in that: The support block is arranged between the high-voltage coil and the low-voltage coil of the winding to support the high-voltage coil and prevent the high-voltage coil from moving out of position, and the end of the insulating pad close to the support block is provided with a groove, and the support block has a protruding part which can extend into the groove and match the shape of the groove, and the side of the support block away from the protruding part is supported between the high-voltage coil and the low-voltage coil to form a supporting part. ​ 2. The short-circuit resistant dry-type transformer of claim 1, wherein: The end of the supporting part is provided with a avoiding installation slot for the insulating cylinder between the high-voltage coil and the low-voltage coil to pass through.

3. The dry-type short-circuit resistant transformer according to claim 1 or 2, characterized in that: The supporting part of the support block is in the shape of a circular arc plate, the inner arc surface of which matches the shape of the outer ring of the low-voltage coil, and the outer arc surface matches the shape of the inner ring of the high-voltage coil.

4. The dry-type short-circuit resistant transformer according to claim 1 or 2, characterized in that: The support block is a silica gel support block.

5. The dry-type short-circuit resistant transformer according to claim 1 or 2, characterized in that: The insulating pad is provided with a group of pressing nail fixing grooves, and the upper and lower clamping pieces are provided with corresponding pressing nails to fix the insulating pad.

6. The short-circuit resistant dry-type transformer of claim 5, wherein: A metal gasket is sleeved on the pressing nail to seal with the pressing nail fixing groove during installation.

7. The short-circuit resistant dry-type transformer of claim 5, wherein: At least one of the upper and lower clamping pieces comprises a bent plate having a vertical plate and a horizontal plate, and the horizontal plate is provided with an overhanging plate corresponding to the position of the insulating pad, and the pressing nail fixing hole of the pressing nail is arranged on the overhanging plate.

8. The short-circuit resistant dry-type transformer of claim 7, wherein: A reinforcing inclined support is arranged between the vertical plate and the overhanging plate.

9. The dry-type short-circuit resistant transformer according to claim 1 or 2, characterized in that: The side of the insulating pad facing the high-voltage coil is provided with a skirt to increase the creepage distance of the surface of the insulating pad.

10. The dry-type short-circuit resistant transformer according to claim 1 or 2, characterized in that: A supporting piece is arranged between the low-voltage coil and the iron core.

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