Distribution transformer with independent oil compartment switch

Abstract

The present invention discloses a distribution transformer with an independent oil chamber switch, the distribution transformer with the independent oil chamber switch comprises: a transformer body, a switch slot with one end open; an on-load voltage-adjusting switch, comprising a sealing plate and a switch body arranged on the sealing plate, the switch body is accommodated in the switch slot, the moving contact is kept in close contact with the static contact through a compression spring, the sealing plate covers the open portion and seals the switch slot. In the present invention, the influence of the switch body on the transformer body during operation can be effectively avoided through the cooperation between the transformer body and the on-load voltage-adjusting switch, while improving the power supply reliability of the distribution transformer with the independent oil chamber switch, and also extending the service life of the distribution transformer with the independent oil chamber switch.

Description

Technical Field

[0001] The invention relates to the technical field of electrical engineering, and in particular to a distribution transformer with an independent oil chamber switch. Background Art

[0002] Distribution transformers are a key link in providing power to residents. Their output voltage directly supplies electricity to residents, and the output voltage qualification rate is a key indicator for assessing the reliability of electricity use. With the implementation of the rural revitalization strategy in recent years, the improvement of the rural power supply qualification rate has received widespread attention. However, the power supply radius of rural distribution lines is large, and the resulting low voltage and overvoltage problems seriously affect the power supply qualification rate. In general, low voltage and overvoltage are mainly concentrated in specific periods of the day. For example, low voltage is prone to occur during peak power consumption periods at noon and in the evening, and overvoltage is prone to occur when the load is low in the second half of the night. Distribution transformers need to adjust the switch many times a day.

[0003] Existing distribution transformers mostly adopt no-load voltage regulation, which is adjusted several times every year with the change of seasons. It is impossible to guarantee voltage regulation in a specific period of time, which reduces the power supply reliability of the distribution transformer. In recent years, on-load voltage regulation distribution transformers have gradually begun to be promoted and applied. The on-load voltage regulation switch and the distribution transformer body in the on-load voltage regulation distribution transformer mostly adopt integrated sealing technology, and the whole is sealed in the oil tank of the on-load voltage regulation distribution transformer. When the on-load voltage regulation switch is switched, an arc will be generated. In terms of arc extinguishing of the on-load voltage regulation switch, oil arc extinguishing and vacuum bubble arc extinguishing are mostly used. When the oil arc is extinguished, the arc causes the insulating oil to decompose, and the insulating oil diffuses to the transformer body, affecting the overall insulation performance; while the vacuum arc extinguishing type When the switch is in frequent mechanical action, metal debris will be generated, causing serious pollution to the insulating oil. At the same time, since the oil circuit of the entire body is connected, the impure oil generated by the action of the on-load voltage-changing switch will circulate in the entire oil tank. After a long period of accumulation, the insulating oil will be deteriorated as a whole, seriously affecting the operating performance of the on-load voltage-changing distribution transformer. The oil needs to be filtered as a whole, and the service life will be significantly reduced, resulting in the existing on-load voltage-changing distribution transformer being unable to meet the needs of long-term and frequent voltage regulation. On the other hand, the mechanical life of the on-load voltage-changing switch will be significantly reduced during long-term action. Once a fault occurs, the on-load voltage-changing distribution transformer must be lifted and overhauled. Long-term power outages during the overhaul will seriously affect the power supply reliability. Summary of the invention

[0004] The main purpose of the present invention is to provide a distribution transformer with an independent oil chamber switch, aiming to solve the technical problems of short service life and poor power supply reliability of the distribution transformer in the prior art.

[0005] To achieve the above-mentioned purpose, the distribution transformer with an independent oil chamber switch includes: a transformer body, which has a switch slot with one end open; an on-load tap-changing switch, including a sealing plate and a switch body arranged on the sealing plate, the switch body is accommodated in the switch slot, and the sealing plate covers the open end and seals the switch slot.

[0006] Optionally, the on-load voltage-regulating switch also includes: a mounting bracket mounted on the switch body, the mounting bracket being provided with a compression spring cavity, the compression spring cavity containing a compression spring; a moving contact, a slot side wall of the switch slot being provided with a static contact corresponding to the moving contact, one end of the moving contact partially extending into the compression spring cavity, the other end of the moving contact abutting against the static contact, and the moving contact group squeezing and compressing the compression spring.

[0007] Optionally, three of the moving contacts form a moving contact group, three of the stationary contacts form a stationary contact group, the number of the mounting brackets is multiple, and each of the compression spring cavities has a moving contact group extending therein. The on-load voltage-regulating switch also includes a driver, which is used to adjust the electrical connection between the reference gear and other gears in the multiple groups of moving contact groups.

[0008] Optionally, each of the moving contacts corresponds to a compression spring, and a guide member is connected between each of the moving contacts and the switch body, the input end of the guide member is connected to the moving contact, the output end of the guide member is connected to the switch body, and the compression spring is located between the input end and the output end.

[0009] Optionally, a threading hole is provided on a slot side wall of the switch slot, the stationary contact passes through the threading hole and extends into the switch slot, and an insulating rubber pad is provided between the stationary contact and the threading hole.

[0010] Optionally, the on-load voltage regulating switch further includes a limit pin accommodated in the compression spring cavity, and the moving contact is connected to the compression spring via the limit pin.

[0011] Optionally, a positioning block is provided on the bottom wall of the switch slot, and the switch body is provided with a positioning hole engaged with the positioning block.

[0012] Optionally, a sealing ring is provided between the sealing plate and the transformer body, and the sealing plate is sealed and connected to the transformer body via the sealing ring.

[0013] Optionally, the distribution transformer of the independent oil chamber switch further includes a plurality of fixing parts, and the sealing plate is connected to the transformer body via the plurality of fixing parts.

[0014] Optionally, a plurality of the fixing members are arranged at intervals at the outer edge of the switch body, a lifting ring is provided on a side of the sealing plate away from the switch slot, and the lifting ring corresponds to the position of the switch body.

[0015] In the technical solution of the present invention, the distribution transformer of the independent oil chamber switch sets the transformer body and the on-load voltage regulating switch as independent components, and seals the switch body in the switch slot through a sealing plate, which can ensure the independence of the switch body; when the distribution transformer of the independent oil chamber switch is working, the switch body of the on-load voltage regulating switch can realize gear adjustment through the internal mechanical structure switching to adjust the voltage of the transformer body, which can improve the reliability of power supply of the distribution transformer of the independent oil chamber switch; when the switch body is in motion, the switch slot and the transformer body are isolated by the slot wall to use the switch slot as an independent oil chamber, so that the switch body is completely isolated from the oil chamber in the transformer body, which can avoid the oil decomposition caused by the arc generated when the switch body is frequently in motion and the metal debris generated by the mechanical action from spreading to the transformer body. In the present invention, through the cooperation between the transformer body and the on-load voltage regulating switch, the influence of the switch body on the transformer body when in motion can be effectively avoided, and while improving the power supply reliability of the distribution transformer of the independent oil chamber switch, the service life of the distribution transformer of the independent oil chamber switch can be extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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 the structures shown in these drawings without paying creative work.

[0017] Figure 1 This is an exploded schematic diagram of a distribution transformer of an independent oil compartment switch according to an embodiment of the present invention;

[0018] Figure 2 A schematic diagram of a partial structure of a transformer body according to an embodiment of the present invention;

[0019] Figure 3 This is a schematic structural diagram of an on-load voltage regulating switch according to an embodiment of the present invention;

[0020] Figure 4 This is a partial structural schematic diagram of a distribution transformer of an independent oil compartment switch according to an embodiment of the present invention.

[0021] Description of Figure Numbers:

[0022]

[0023]

[0024] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0026] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0027] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0028] The invention provides a distribution transformer with an independent oil chamber switch.

[0029] like Figure 1 As shown, in one embodiment of the present invention, a distribution transformer 100 with an independent oil chamber switch includes a transformer body 1 and an on-load tap-changing switch 2; the transformer body 1 is provided with a switch slot 11 with one end open; the on-load tap-changing switch 2 includes a sealing plate 21 and a switch body 22 arranged on the sealing plate 21, the switch body 22 is accommodated in the switch slot 11, and the sealing plate 21 covers the open portion and seals the switch slot 11.

[0030] The distribution transformer 100 with an independent oil chamber switch in this embodiment sets the transformer body 1 and the on-load voltage regulating switch 2 as independent components, and seals the switch body 22 in the switch slot 11 through a sealing plate 21, which can ensure the independence of the switch body 22; when the distribution transformer 100 with an independent oil chamber switch is working, the switch body 22 of the on-load voltage regulating switch 2 can achieve gear adjustment through internal mechanical structure switching to adjust the voltage of the transformer body 1, which can improve the power supply reliability of the distribution transformer 100 with an independent oil chamber switch; when the switch body 22 is in motion, the switch slot 11 and the transformer body 1 are isolated by the slot wall, and the switch slot 11 is used as an independent oil chamber, so that the switch body 22 is completely isolated from the oil chamber in the transformer body 1, which can avoid the oil decomposition caused by the arc generated when the switch body 22 is frequently operated and the metal debris generated by the mechanical action from spreading to the transformer body 1. In this embodiment, the cooperation between the transformer body 1 and the on-load tap-changing switch 2 can effectively avoid the influence of the switch body 22 on the transformer body 1 when it is in operation. While improving the power supply reliability of the distribution transformer 100 with an independent oil chamber switch, it can also extend the service life of the distribution transformer 100 with an independent oil chamber switch.

[0031] In one embodiment, the on-load voltage-changing switch 2 further includes a mounting bracket 23 and a moving contact 241; the mounting bracket 23 is mounted on the switch body 22, and the mounting bracket 23 is provided with a compression spring cavity 231, and a compression spring 232 is placed in the compression spring cavity 231; the slot side wall of the switch slot 11 is provided with a static contact 121 corresponding to the moving contact 241, one end of the moving contact 241 partially extends into the compression spring cavity 231, and the other end of the moving contact 241 abuts against the static contact 121, and the moving contact group 24 squeezes and compresses the compression spring 232. The transformer body 1 in this embodiment can connect the high-voltage bushing and the winding tap to the static contact 121 through a high-voltage lead, and winding taps of different gears are connected to different static contacts 121, such as Figure 4 As shown, the compression spring 232 and the moving contact 241 both extend in the left-right direction. When assembling the on-load tap-changing switch 2, the compression spring 232 can be first installed in the compression spring cavity 231, and then the right end of the moving contact 241 can be abutted against the static contact 121, so that the left end of the moving contact 241 squeezes and compresses the compression spring 232, so that the elastic force generated by the elastic deformation of the compression spring 232 ensures the good crimping of the moving contact 241 and the static contact 121, thereby improving the conductive reliability of the on-load tap-changing switch 2.

[0032] Furthermore, three moving contacts 241 form a moving contact group 24, three stationary contacts 121 form a stationary contact group 12, the number of mounting brackets 23 is plural, each compression spring cavity 231 has a moving contact group 24 inserted therein, and the on-load voltage-regulating switch 2 further includes a driver 26. In one embodiment, the number of gears of the on-load voltage-regulating switch 2 is N, the number of moving contacts 241 is 3 (N+1), and one of the groups is a reference gear of the moving contact group 24. When adjusting the gear, the switch body 22 can realize an electrical connection between the reference gear and the three moving contacts 241 of any group of gears among the N switch gears through the driver 26, thereby realizing switch adjustment. Figure 2 and Figure 3 As shown, the number of gears of the on-load voltage regulating switch 2 is 3, the number of moving contacts 241 is 12, and the number of the static contact group 12 is consistent with that of the moving contact group 24 and is arranged in one-to-one correspondence. It should be noted that the arc extinguisher in this embodiment is arranged in the on-load voltage regulating switch 2, and the on-load voltage regulating switch 2 is provided with a voltage regulating control module, and the control logic of the voltage regulating control module of the on-load voltage regulating switch 2 is set. The voltage regulating control module controls the driver 26 according to the detected input terminal voltage, thereby automatically adjusting the switch gear, and realizing the automatic voltage regulation of the distribution transformer 100 of the independent oil chamber switch.

[0033] In addition, the on-load tap-changing switch 2 in this embodiment is connected to the high-voltage side of the distribution transformer 100 of the independent oil chamber switch. The distribution transformer 100 of the independent oil chamber switch takes out various gear taps from the high-voltage side, and is connected to the three-phase connection terminals of each gear in the static contact 121 through leads in the transformer body 1, wherein the reference gear static contact 121 is connected to the rated gear on the high-voltage side. The input side of the distribution transformer 100 of the independent oil chamber switch is connected to the rated gear position on the high-voltage side through a high-voltage bushing. After the switch body 22 is placed in the switch slot 11, all the moving contacts 241 are reliably connected to all the static contacts 121, and then the gear is adjusted through the driver 26 to achieve electrical connection between the reference gear and the moving contact 241 of the gear to be adjusted, thereby achieving electrical connection between the coil tap of the rated gear and the coil tap of the gear to be adjusted. The two taps are of equal potential, which changes the number of turns of the primary winding of the distribution transformer 100 of the independent oil chamber switch, changes the transformation ratio of the distribution transformer 100 of the independent oil chamber switch, and changes the output voltage of the distribution transformer 100 of the independent oil chamber switch accordingly. Finally, the distribution transformer 100 of the independent oil chamber switch can be adjusted. By connecting a conventional freewheeling circuit in parallel between the gears of the gear adjustment switch, the purpose of on-load voltage regulation can be achieved.

[0034] In another embodiment, each movable contact 241 corresponds to a compression spring 232, and a flow guide 25 is connected between each movable contact 241 and the switch body 22, the input end of the flow guide 25 is connected to the movable contact 241, the output end of the flow guide 25 is connected to the switch body 22, and the compression spring 232 is located between the input end and the output end. The flow guide 25 is connected across the switch body 22 and the movable contact 241, and the resistivity of the flow guide 25 is small, which can effectively avoid the current flowing through the compression spring 232, thereby improving the conductivity reliability of the on-load voltage regulating switch 2.

[0035] In this embodiment, a threading hole 13 is provided on the side wall of the switch slot 11, and the static contact 121 passes through the threading hole 13 and extends into the switch slot 11, and an insulating rubber pad is provided between the static contact 121 and the threading hole 13. The insulating rubber pad in this embodiment is an oil-resistant insulating rubber pad, and the threading hole 13 can be sealed by the insulating rubber pad, which facilitates the installation of the static contact 121 and can also prevent the switch body 22 in the switch slot 11 from frequently operating and affecting the transformer body 1.

[0036] In the distribution transformer 100 with an independent oil chamber switch in this embodiment, the on-load voltage regulating switch 2 also includes a limit pin 27 accommodated in the compression spring cavity 231, and the moving contact 241 is connected to the compression spring 232 through the limit pin 27. The limit pin 27 in this embodiment can fix the position of the moving contact 241 and the compression spring 232, and the compression spring 232 is kept in a compressed state by the limit pin 27, so that when the moving contact 241 is squeezed to the left, the squeezing force will be transmitted to the compression spring 232, and the compression spring 232 is always kept under compression, thereby improving the stability of the on-load voltage regulating switch 2. Figure 2 and Figure 3 As shown, a positioning block 14 is disposed on the bottom wall of the switch slot 11 , and a positioning hole 221 engaged with the positioning block 14 is disposed on the switch body 22 . In one embodiment, three positioning blocks 14 are sequentially arranged at intervals along the length direction of the switch slot 11 .

[0037] Specifically, Figure 2 and Figure 3As shown, the center distance between the positioning block 14 and the plane where the static contact 121 is located is k1, and the center distance between the positioning hole 221 in the switch body 22 and the plane where the moving contact 241 is located when the compression spring 232 is in normal travel is k2, and k1<k2. When the switch body 22 is placed in the switch slot 11, the spring will be in a compressed state, and the crimping force and crimping area of ​​the moving contact 241 and the static contact 121 can be adjusted by adjusting the difference between k1 and k2, thereby ensuring good crimping of the moving and static contacts 121, and facilitating the adjustment of the on-load tap-changing switch 2. In one embodiment, the center distance between the positioning block 14 and the plane where the static contact 121 is located is k1=10cm, and the center distance between the positioning hole 221 and the plane where the moving contact 241 is located is k2=15cm, which can ensure that the compression stroke of the compression spring 232 is 5cm. When the required crimping force of the moving and static contacts 121 is 1kN, the compression spring 232 with a spring coefficient of 0.2kN / cm can be selected according to the required crimping force.

[0038] Specifically, the distribution transformer 100 with an independent oil chamber switch further includes a plurality of fixing members 4, the sealing plate 21 is connected to the transformer body 1 through the plurality of fixing members 4, and a sealing ring 3 is provided between the sealing plate 21 and the transformer body 1, and the sealing plate 21 is sealedly connected to the transformer body 1 through the sealing ring 3. The fixing members 4 in this embodiment may be bolts, the sealing plate 21 may be connected to the transformer body 1 through the plurality of fixing members 4, and the sealing ring 3 is provided between the sealing plate 21 and the transformer body 1, so that the sealing ring 3 is arranged around the open edge of the switch slot 11 to improve the sealing performance of the switch slot 11.

[0039] In this embodiment, a plurality of fixing members 4 are arranged at intervals at the outer edge of the switch body 22, and a lifting ring 211 is arranged on the side of the sealing plate 21 away from the groove 11, and the lifting ring 211 corresponds to the position of the switch body 22. Figure 1 As shown, in one embodiment, there are two lifting rings 211, and the two lifting rings 211 are arranged on the outer surface of the sealing plate 21. When the on-load voltage regulating switch 2 needs to be repaired, the fixing member 4 can be removed, and the switch body 22 can be taken out from the switch slot 11 through the lifting ring 211, and the small amount of oil in the switch slot 11 can be replaced, which will not affect the transformer body 1 and facilitate the maintenance of the on-load voltage regulating switch 2. In addition, when the on-load voltage regulating switch 2 is damaged, the power supply can be restored by directly placing the spare on-load voltage regulating switch 2 into the switch slot 11, and the replacement workload is small, which effectively reduces the power outage time when the on-load voltage regulating switch 2 fails, and improves the power supply stability of the distribution transformer 100 with an independent oil chamber switch.

[0040] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A distribution transformer with an independent oil compartment switch, characterized in that: The distribution transformer (100) of the independent oil compartment switch comprises: The transformer body (1) is provided with a switch slot (11) with one end open; An on-load voltage regulating switch (2) comprises a sealing plate (21) and a switch body (22) arranged on the sealing plate (21), wherein the switch body (22) is accommodated in the switch slot (11), and the sealing plate (21) covers the open portion and seals the switch slot (11); A positioning block (14) is provided on the bottom wall of the switch slot (11), and a positioning hole (221) is provided on the switch body (22) for clamping with the positioning block (14); The on-load voltage regulating switch (2) further comprises: A mounting bracket (23) is mounted on the switch body (22); the mounting bracket (23) is provided with a compression spring cavity (231), and a compression spring (232) is placed in the compression spring cavity (231); A moving contact (241), a slot side wall of the switch slot (11) corresponding to the moving contact (241) is provided with a stationary contact (121), one end of the moving contact (241) partially extends into the compression spring cavity (231), the other end of the moving contact (241) abuts against the stationary contact (121), and the moving contact (241) squeezes and compresses the compression spring (232); The center distance between the positioning block (14) and the plane where the static contact (121) is located is k1, and the center distance between the positioning hole (221) and the plane where the moving contact (241) is located when the compression spring (232) is in normal travel is k2, and k1<k2. When the switch body (22) is placed in the switch slot (11), the compression spring (232) is in a compressed state, and the crimping force and crimping area between the moving contact (241) and the static contact (121) can be adjusted by adjusting the difference between k1 and k2.

2. The distribution transformer with independent oil compartment switch according to claim 1, characterized in that: The three moving contacts (241) form a moving contact group (24), the three stationary contacts (121) form a stationary contact group (12), the number of the mounting brackets (23) is multiple, and each of the compression spring cavities (231) has a moving contact group (24) inserted therein, and the on-load voltage regulating switch (2) further includes a driver (26), and the driver (26) is used to adjust the electrical connection between the reference gear and other gears in the multiple groups of moving contact groups (24).

3. The distribution transformer with independent oil compartment switch according to claim 2, characterized in that: Each of the movable contacts (241) corresponds to a compression spring (232), and a flow guide (25) is connected between each of the movable contacts (241) and the switch body (22), the input end of the flow guide (25) is connected to the movable contact (241), the output end of the flow guide (25) is connected to the switch body (22), and the compression spring (232) is located between the input end and the output end.

4. The distribution transformer with independent oil compartment switch according to claim 1, characterized in that: A threading hole (13) is provided on the side wall of the switch slot (11), the stationary contact (121) passes through the threading hole (13) and extends into the switch slot (11), and an insulating rubber pad is provided between the stationary contact (121) and the threading hole (13).

5. The distribution transformer with independent oil compartment switch according to claim 1, characterized in that: The on-load voltage regulating switch (2) further comprises a limit pin (27) accommodated in the compression spring cavity (231), and the moving contact (241) is connected to the compression spring (232) via the limit pin (27).

6. The distribution transformer with independent oil compartment switch according to any one of claims 1 to 5, characterized in that: A sealing ring (3) is provided between the sealing plate (21) and the transformer body (1), and the sealing plate (21) is sealedly connected to the transformer body (1) via the sealing ring (3).

7. The distribution transformer with independent oil compartment switch according to any one of claims 1 to 5, characterized in that: The distribution transformer (100) with an independent oil chamber switch further comprises a plurality of fixing members (4), and the sealing plate (21) is connected to the transformer body (1) via the plurality of fixing members (4).

8. The distribution transformer with independent oil compartment switch according to claim 7, characterized in that: A plurality of the fixing members (4) are arranged at intervals on the outer edge of the switch body (22); a lifting ring (211) is arranged on the side of the sealing plate (21) facing away from the switch slot (11), and the lifting ring (211) corresponds to the position of the switch body (22).

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