阅读说明：本技术 有载分接开关的切换芯子和有载分接开关 (Switching core of on-load tap-changer and on-load tap-changer ) 是由 周海滨 邓军 吕金壮 张长虹 张晋寅 刘青松 潘志城 谢志成 吴瀛 梁晨 于 2021-09-18 设计创作，主要内容包括：本申请提供了一种真空有载分接开关的切换芯子和真空有载分接开关,切换芯子包括上表面由关于第一轴线对称的第一区域和第二区域构成的第一安装盘,第一真空灭弧单元和第二真空灭弧单元分别安装在第一区域和第二区域上,且使第一真空灭弧单元和第二真空灭弧单元关于第一轴线对称,第一真空灭弧单元、第二真空灭弧单元分别与过渡触头单元中的过渡触头、主触头单元中对应的主触头、过渡电阻单元中对应的过渡电阻构成对称的具有第一切换机构与第二切换机构的切换芯子,包含该切换芯子的真空有载分接开关在应用于换流变压器的两个柱头调压时受力均匀,故障率低,可靠性高。(The application provides a switching core of a vacuum on-load tap-changer and the vacuum on-load tap-changer, the switching core comprises a first mounting plate, the upper surface of the first mounting plate is composed of a first area and a second area which are symmetrical about a first axis, a first vacuum arc extinguishing unit and a second vacuum arc extinguishing unit are respectively mounted on the first area and the second area, the first vacuum arc extinguishing unit and the second vacuum arc extinguishing unit are symmetrical about the first axis, the first vacuum arc extinguishing unit and the second vacuum arc extinguishing unit respectively form a switching core which is symmetrical and provided with a first switching mechanism and a second switching mechanism with a transition contact in a transition contact unit, a main contact corresponding to the main contact unit and a transition resistance corresponding to the transition resistance unit, the vacuum on-load tap-changer comprising the switching core is stressed uniformly when being applied to the voltage regulation of two column heads of a converter transformer, and has low failure rate, the reliability is high.)

1. A switching core for a vacuum on-load tap changer comprising:

a first mounting plate, a first surface of which is constituted by a first region and a second region that are symmetrical with respect to a first axis;

a first vacuum interrupter unit mounted on the first region;

a second vacuum arc extinguishing unit installed on the second area and symmetrical to the first vacuum arc extinguishing unit about the first axis;

the transition contact unit is installed on the first surface of the first installation disc and is respectively connected with the first vacuum arc extinguishing chamber unit and the second vacuum arc extinguishing unit;

the main contact unit is respectively connected with the first vacuum arc extinguishing chamber unit, the second vacuum arc extinguishing unit and the transition contact unit;

and the transition resistance unit is respectively connected with the transition contact unit and the main contact unit.

2. The switching core according to claim 1, wherein the first vacuum interrupter unit includes a first vacuum interrupter and a second vacuum interrupter;

the second vacuum arc extinguishing unit comprises a third vacuum arc extinguishing chamber and a fourth vacuum arc extinguishing chamber;

a first connecting line between the central point of the first vacuum arc-extinguishing chamber and the central point of the second vacuum arc-extinguishing chamber is parallel to the first axis;

a second connecting line between the central point of the third vacuum arc-extinguishing chamber and the central point of the fourth vacuum arc-extinguishing chamber is parallel to the first axis;

the first and third vacuum chambers are symmetric about the first axis;

the second vacuum chamber and the fourth vacuum chamber are symmetric about the first axis.

3. The switching core according to claim 2, wherein the excess contact unit comprises:

the first transition contact comprises a first transition moving contact, a first transition fixed contact and a second transition fixed contact, the first transition moving contact is connected with the first vacuum arc-extinguishing chamber, the first transition fixed contact is connected with the main contact unit, and the second transition fixed contact is connected with the transition resistance unit;

the second transition contact comprises a second transition moving contact, a third transition fixed contact and a fourth transition fixed contact, the second transition moving contact is connected with the second vacuum arc-extinguishing chamber, the third transition fixed contact is connected with the main contact unit, and the fourth transition fixed contact is connected with the transition resistance unit;

the third transition contact comprises a third transition moving contact, a fifth transition fixed contact and a sixth transition fixed contact, the third transition moving contact is connected with the third vacuum arc-extinguishing chamber, the fifth transition fixed contact is connected with the main contact unit, and the sixth transition fixed contact is connected with the transition resistance unit;

and the fourth transition contact comprises a fourth transition moving contact, a seventh transition fixed contact and an eighth transition fixed contact, the fourth transition moving contact is connected with the fourth vacuum arc-extinguishing chamber, the seventh transition fixed contact is connected with the contact unit, and the eighth transition fixed contact is connected with the transition resistance unit.

4. The switching core according to claim 3, wherein the first excess contact and the third excess contact are disposed on a first level;

the second transition contact and the fourth transition contact are disposed on a second level;

a first distance between the first transition contact and a center point of the first mounting plate is equal to a second distance between the third transition contact and the center point of the first mounting plate;

a third distance between the second transition contact and the center point of the first mounting pad is equal to a fourth distance between the fourth transition contact and the center point of the first mounting pad.

5. The switching core according to claim 3, wherein the transition movable contact in the transition contact unit is rotated in a shaft rotation manner to make point contact with the corresponding transition stationary contact.

6. The switching core according to claim 1, further comprising a second mounting plate disposed concentrically with the first mounting disk, a first surface of the second mounting plate being opposite to a second surface of the first mounting plate, the second surface of the first mounting plate being opposite to the first surface of the first mounting plate;

the first surface of the second mounting plate is constituted by a third region and a fourth region that are symmetrical about a second axis;

the main contact unit includes a first main contact group located on the third region and a second main contact group located on the fourth region;

the first and second main contact groups are symmetrical about the second axis.

7. The switching core according to claim 6, further comprising a third mounting disk concentrically disposed with the second mounting disk, a first surface of the third mounting disk opposing a second surface of the second mounting disk, the second surface of the second mounting disk being a face opposing the first surface of the second mounting disk;

the first surface of the third mounting plate is constituted by a fifth region and a sixth region that are symmetrical about a third axis;

the excess resistance unit includes a first excess resistance group on the fifth region and a second excess resistance group on the sixth region;

the first and second sets of excess resistances are symmetric about the third axis.

8. The switching core according to claim 7, further comprising:

the rotating shaft sequentially penetrates through the center of the first surface of the third mounting plate, the center of the first surface of the second mounting plate and the center of the first surface of the first mounting plate;

the quick mechanism is arranged on a second surface of the third mounting plate, the second surface of the third mounting plate is a surface opposite to the first surface of the third mounting plate, the quick mechanism comprises a spring part, and the energy released by the spring part drives the rotating shaft to rotate;

the rotation of the rotating shaft drives the first mounting disc, the second mounting disc and the third mounting disc to correspondingly rotate, so that the first vacuum arc extinguishing unit, the second vacuum arc extinguishing unit, the transition contact unit and the main contact unit are driven to execute corresponding switch switching actions.

9. A vacuum on-load tap changer comprising:

the switching core according to any one of claims 1 to 8;

the central rotating shaft of the tapping selector is connected with the rotating shaft of the switching core through a shaft sleeve;

the tapping selector comprises a first tapping selection unit and a second tapping selection unit, wherein the first tapping selection unit is arranged corresponding to the first vacuum arc extinguishing unit, and the second tapping selection unit is arranged corresponding to the second vacuum arc extinguishing unit.

10. The vacuum on-load tap changer of claim 9, further comprising:

the potential resistance unit is connected with the tapping selector, comprises a potential resistance and a potential switch which are sequentially connected and is used for limiting the suspended potential discharge in the polarity conversion process of the on-load tapping switch;

and the operating mechanism is respectively connected with the switching core and the tapping selector and is used for driving the switching core and the tapping selector to execute corresponding switching actions.

Technical Field

The invention relates to the technical field of transformer voltage regulation, in particular to a switching core of an on-load tap-changer and the on-load tap-changer.

Background

An On-load Tap Changer (OLTC) refers to a voltage regulating device adapted to operate under transformer excitation or load for changing the Tap connection position of a transformer winding. The basic principle is to realize the switching between taps in the transformer winding under the condition of ensuring that the load current is not interrupted, thereby changing the number of turns of the winding, namely the voltage ratio of the transformer, and finally realizing the purpose of voltage regulation. The on-load tap changer is used as a core component for completing on-load voltage regulation of the transformer, and the performance state of the on-load tap changer is directly related to the safe operation of the on-load voltage regulation transformer. According to relevant data statistics, the on-load tap-changer fault caused by the on-load tap-changer fault accounts for about 40% of the total fault.

The voltage of the converter transformer is adjusted frequently in operation, the average annual voltage adjustment times are 5000-7000 times, and the maximum voltage can reach 1 ten thousand times per year, so that the on-load tap-changer is required to have long-term safety and reliability, and can meet the requirements of less maintenance or no maintenance after more operation times. Obviously, compared with an on-load tap-changer applied to a three-phase alternating-current transformer in a power system, the on-load tap-changer applied to a converter transformer has more severe operation conditions, and the performance of the on-load tap-changer needs to meet higher requirements.

However, in recent years, on-load tap-changers of converter transformers frequently have faults, and the structure of the on-load tap-changers applied to the converter transformers needs to be optimized to ensure the operational reliability of the on-load tap-changers, so that the on-load tap-changers are not easy to frequently have faults.

Disclosure of Invention

Based on this, the application provides a switching core and vacuum on-load tap-changer of vacuum on-load tap-changer to improve vacuum on-load tap-changer's operational reliability.

A switching core for a vacuum on-load tap changer comprising:

a first mounting plate, a first surface of which is constituted by a first region and a second region that are symmetrical with respect to a first axis;

a first vacuum interrupter unit mounted on the first region;

a second vacuum arc extinguishing unit installed on the second area and symmetrical to the first vacuum arc extinguishing unit about the first axis;

the transition contact unit is installed on the first surface of the first installation disc and is respectively connected with the first vacuum arc extinguishing chamber unit and the second vacuum arc extinguishing unit;

the main contact unit is respectively connected with the first vacuum arc extinguishing chamber unit, the second vacuum arc extinguishing unit and the transition contact unit;

and the transition resistance unit is respectively connected with the transition contact unit and the main contact unit.

In some embodiments, the first vacuum arc extinguishing unit comprises a first vacuum arc extinguishing chamber and a second vacuum arc extinguishing chamber;

the second vacuum arc extinguishing unit comprises a third vacuum arc extinguishing chamber and a fourth vacuum arc extinguishing chamber;

a first connecting line between the central point of the first vacuum arc-extinguishing chamber and the central point of the second vacuum arc-extinguishing chamber is parallel to the first axis;

a second connecting line between the central point of the third vacuum arc-extinguishing chamber and the central point of the fourth vacuum arc-extinguishing chamber is parallel to the first axis;

the first and third vacuum chambers are symmetric about the first axis;

the second vacuum chamber and the fourth vacuum chamber are symmetric about the first axis.

In some embodiments, the transition contact unit includes:

the first transition contact comprises a first transition moving contact, a first transition fixed contact and a second transition fixed contact, the first transition moving contact is connected with the first vacuum arc-extinguishing chamber, the first transition fixed contact is connected with the main contact unit, and the second transition fixed contact is connected with the transition resistance unit;

the second transition contact comprises a second transition moving contact, a third transition fixed contact and a fourth transition fixed contact, the second transition moving contact is connected with the second vacuum arc-extinguishing chamber, the third transition fixed contact is connected with the main contact unit, and the fourth transition fixed contact is connected with the transition resistance unit;

the third transition contact comprises a third transition moving contact, a fifth transition fixed contact and a sixth transition fixed contact, the third transition moving contact is connected with the third vacuum arc-extinguishing chamber, the fifth transition fixed contact is connected with the main contact unit, and the sixth transition fixed contact is connected with the transition resistance unit;

and the fourth transition contact comprises a fourth transition moving contact, a seventh transition fixed contact and an eighth transition fixed contact, the fourth transition moving contact is connected with the fourth vacuum arc-extinguishing chamber, the seventh transition fixed contact is connected with the contact unit, and the eighth transition fixed contact is connected with the transition resistance unit.

In some embodiments, the first transition contact and the third transition contact are disposed on a first level;

the second transition contact and the fourth transition contact are disposed on a second level;

a first distance between the first transition contact and a center point of the first mounting plate is equal to a second distance between the third transition contact and the center point of the first mounting plate;

a third distance between the second transition contact and the center point of the first mounting pad is equal to a fourth distance between the fourth transition contact and the center point of the first mounting pad.

In some embodiments, the transition movable contact in the transition contact unit is rotated in a shaft rotation manner to make point contact with the corresponding transition stationary contact.

In some embodiments, the switching core further comprises a second mounting plate disposed concentrically with the first mounting disk, a first surface of the second mounting plate being opposite to a second surface of the first mounting plate, the second surface of the first mounting plate being opposite to the first surface of the first mounting plate;

the first surface of the second mounting plate is constituted by a third region and a fourth region that are symmetrical about a second axis;

the main contact unit includes a first main contact group located on the third region and a second main contact group located on the fourth region;

the first and second main contact groups are symmetrical about the second axis.

In some embodiments, the switching core further comprises a third mounting plate disposed concentrically with the second mounting disk, a first surface of the third mounting plate being opposite to a second surface of the second mounting plate, the second surface of the second mounting plate being opposite to the first surface of the second mounting plate;

the first surface of the third mounting plate is constituted by a fifth region and a sixth region that are symmetrical about a third axis;

the excess resistance unit includes a first excess resistance group on the fifth region and a second excess resistance group on the sixth region;

the first and second sets of excess resistances are symmetric about the third axis.

In some embodiments, the switching core further comprises:

the rotating shaft sequentially penetrates through the center of the first surface of the third mounting plate, the center of the first surface of the second mounting plate and the center of the first surface of the first mounting plate;

the quick mechanism is arranged on a second surface of the third mounting plate, the second surface of the third mounting plate is a surface opposite to the first surface of the third mounting plate, the quick mechanism comprises a spring part, and the energy released by the spring part drives the rotating shaft to rotate;

the rotation of the rotating shaft drives the first mounting disc, the second mounting disc and the third mounting disc to correspondingly rotate, so that the first vacuum arc extinguishing unit, the second vacuum arc extinguishing unit, the transition contact unit and the main contact unit are driven to execute corresponding switch switching actions.

A vacuum on-load tap changer comprising:

a switching core as claimed in any one of the above;

the central rotating shaft of the tapping selector is connected with the rotating shaft of the switching core through a shaft sleeve;

the tapping selector comprises a first tapping selection unit and a second tapping selection unit, wherein the first tapping selection unit is arranged corresponding to the first vacuum arc extinguishing unit, and the second tapping selection unit is arranged corresponding to the second vacuum arc extinguishing unit.

In some embodiments, the vacuum on-load tap changer further comprises:

the potential resistance unit is connected with the tapping selector, comprises a potential resistance and a potential switch which are sequentially connected and is used for limiting the suspended potential discharge in the polarity conversion process of the on-load tapping switch;

and the operating mechanism is respectively connected with the switching core and the tapping selector and is used for driving the switching core and the tapping selector to execute corresponding switching actions.

The application provides a switching core of a vacuum on-load tap-changer and the vacuum on-load tap-changer, comprising a first mounting plate, the upper surface of which is composed of a first area and a second area which are symmetrical about a first axis, a first vacuum arc extinguishing unit and a second vacuum arc extinguishing unit are respectively mounted on the first area and the second area, and the first vacuum arc extinguishing unit and the second vacuum arc extinguishing unit are symmetrical about a first axis, the first vacuum arc extinguishing unit and the second vacuum arc extinguishing unit respectively form a symmetrical switching core with a first switching mechanism and a second switching mechanism with a transition contact in the transition contact unit, a corresponding main contact in the main contact unit and a corresponding transition resistor in the transition resistor unit, and the vacuum on-load tap-changer comprising the switching core is uniformly stressed when applied to voltage regulation of two column heads of a converter transformer, so that the fault rate is low, and the reliability is high.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural view of a switching core of a vacuum on-load tap changer according to the present application;

FIG. 2 is a top view of a first mounting disk with first and second vacuum arc extinguishing units mounted thereon;

FIG. 3 is a top view of a first mounting disk with a transition contact unit disposed thereon;

figure 4 is a top view of a second mounting disk with the main contact unit mounted thereon;

FIG. 5 is a top view of a third mounting disk with a transition resistance unit mounted thereon;

fig. 6 is a schematic structural diagram of a tap selector according to the present application.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Embodiments of the present application are set forth in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It will be understood that, as used herein, the terms "first," "second," and the like may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, a first resistance may be referred to as a second resistance, and similarly, a second resistance may be referred to as a first resistance, without departing from the scope of the present application. The first resistance and the second resistance are both resistances, but they are not the same resistance.

It is to be understood that "connection" in the following embodiments is to be understood as "electrical connection", "communication connection", and the like if the connected circuits, modules, units, and the like have communication of electrical signals or data with each other.

As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," "includes" or "including," etc., specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

The existing on-load tap-changer is generally a three-phase on-load tap-changer, three phases are uniformly arranged on the circumference according to an angle of 120 degrees, and each phase corresponds to the voltage regulation of one phase of a three-phase alternating current transformer. However, the converter transformer is generally a single-phase dual-column transformer, and when the existing three-phase on-load tap-changer is used for voltage regulation of two columns of the on-load tap-changer, one phase of the three-phase on-load tap-changer is idle, which causes uneven stress on the on-load tap-changer during the action of the on-load tap-changer, so that a supporting structure of the on-load tap-changer is randomly damaged or cracked, and if mechanical failure of the on-load tap-changer cannot be found in time, mechanical failure of the on-load tap-changer occurs. In addition, three groups of contacts are required to be arranged on an installation disc of the existing three-phase on-load tap-changer, the contact margin is small, discharging is easy to occur under the condition that insulating oil is polluted or foreign matters exist, and the fault frequency of the on-load tap-changer can be increased.

After finding and analyzing the problems of the existing on-load tap-changer, researchers of the application design a switching core of a vacuum on-load tap-changer applied to voltage regulation of two column ends of a single-phase double-column-head converter transformer and the vacuum on-load tap-changer.

Fig. 1 is a schematic structural diagram of a switching core of a vacuum on-load tap changer according to an embodiment of the present application. Fig. 2 to 5 are top views of the individual components of fig. 1, respectively, viewed from above. The structure of the switching core provided in the present application is specifically described below with reference to fig. 1 to 5.

As shown in fig. 1, the switching core provided by the present application mainly includes a first mounting plate 1a, a first vacuum arc extinguishing unit 111, a second vacuum arc extinguishing unit 112, a transition contact unit 12, a main contact unit 13, and a transition resistance unit 14.

As shown in fig. 2, a plan view of the first mounting plate 1a on which the first vacuum arc extinguishing unit 111 and the second vacuum arc extinguishing unit 112 are mounted is shown. An upper surface (first surface) of the first mounting plate 1a is a mounting surface of the vacuum arc extinguishing unit, and the upper surface of the first mounting plate 1a is constituted by a first region and a second region that are symmetrical with respect to the first axis ab. The first vacuum interrupter unit 111 is mounted on a first region of the first mounting plate 1a, and the second vacuum interrupter unit 112 is mounted on a second region of the first mounting plate 1a, and is symmetrical to the first vacuum interrupter unit 111 about a first axis ab. A vertical connection line between the first vacuum arc extinguishing unit 111 and the center point of the first mounting plate 1a forms an angle of 180 degrees with a vertical connection line between the second vacuum arc extinguishing unit 112 and the center point of the first mounting plate 1 a.

The transition contact unit 12 is located above the first mounting plate 1a, i.e. mounted close to the first surface of the first mounting plate 1a, and is connected to the first vacuum interrupter unit 111 and the second vacuum interrupter unit 112, respectively. The main contact unit 13 is connected to the first vacuum interrupter unit 111, the second vacuum interrupter unit 112, and the transition contact unit 12, respectively; the excess resistance unit 14 is connected to the excess contact unit 12 and the main contact unit 13, respectively. In some embodiments, the transition contact unit 12 further includes a first transition contact group correspondingly connected to the first vacuum interrupter unit 111 and a second transition contact group correspondingly connected to the second vacuum interrupter unit 112, the main contact unit 13 further includes a first main contact group correspondingly connected to the first vacuum interrupter unit 111 and a second main contact group correspondingly connected to the second vacuum interrupter unit 112, and the transition resistance unit 14 further includes a first transition resistance group correspondingly connected to the first vacuum interrupter unit 111 and a second transition resistance group correspondingly connected to the second vacuum interrupter unit 112. The first vacuum arc extinguishing unit 111, the first transition contact group, the first main contact group and the first transition resistor group form a first switching mechanism, and the second vacuum arc extinguishing unit 112, the second transition contact group, the second main contact group and the second transition resistor form a second switching mechanism. The first switching mechanism and the second switching mechanism are symmetrically arranged and are respectively used for switching the voltages of the two column heads of the converter transformer. The specific configurations of the first transition contact group, the second transition contact group, the first main contact group, the second main contact group, the first transition resistor, and the second transition resistor are described in detail later with reference to fig. 3 to 5.

The switching core of the vacuum on-load tap-changer comprises a first mounting disc, wherein the upper surface of the first mounting disc is composed of a first area and a second area which are symmetrical about a first axis, a first vacuum arc extinguishing unit and a second vacuum arc extinguishing unit are respectively mounted on the first area and the second area, the first vacuum arc extinguishing unit and the second vacuum arc extinguishing unit are symmetrical about the first axis, the first vacuum arc extinguishing unit and the second vacuum arc extinguishing unit are respectively symmetrical with a transition contact in the transition contact unit, a main contact corresponding to the main contact unit and a transition resistor corresponding to the transition resistance unit, and the switching core is provided with a first switching mechanism and a second switching mechanism.

With continued reference to fig. 2, the first vacuum arc-extinguishing unit 111 includes a first vacuum arc-extinguishing chamber 1111 and a second vacuum arc-extinguishing chamber 1112; the second vacuum arc extinguishing unit 1121 includes a third vacuum arc extinguishing chamber 1121 and a fourth vacuum arc extinguishing chamber 1122. A first connection line L1 between the center point of the first vacuum interrupter 1111 and the center point of the second vacuum interrupter 1112 is parallel to the first axis ab; a second connection line L2 between a center point of the third vacuum interrupter 1121 and a center point of the fourth vacuum interrupter 1122 is parallel to the first axis ab, the first vacuum interrupter 1111 and the third vacuum interrupter 1121 are symmetrical with respect to the first axis ac, and the second vacuum interrupter 1121 and the third vacuum interrupter 1122 are symmetrical with respect to the first axis ac. That is, the center point of the square defined by the first vacuum interrupter 1111, the second vacuum interrupter 1112, the third vacuum interrupter 1121, and the fourth vacuum interrupter 1122 coincides with the center point of the first mounting plate 1a in the up-down direction. Here, the vertical direction refers to the stacking direction of the first mounting plate 1a, the main contact unit 13, and the transition resistance unit 14.

Fig. 3 is a top view of the transition contact unit 12, which further includes a first transition contact 121, a second transition contact 122, a third transition contact 123, and a fourth transition contact 124.

The first transition contact 121 includes a first transition moving contact 1211, a first transition stationary contact 1212, and a second transition stationary contact 1213. The first transition moving contact 1211 is connected to the first vacuum interrupter 1111, the first transition stationary contact 1212 is connected to the main contact unit 13, and the second transition stationary contact 1213 is connected to the transition resistance unit 14. Specifically, the first transition moving contact 1211 is connected to the other end of the first vacuum interrupter 1111, which is opposite to the one end fixed to the first mounting plate 1a, and the upper surface potential of the first mounting plate 1a is a neutral zero potential.

The second transition contact 122 includes a second transition moving contact 1221, a third transition fixed contact 1222, and a fourth transition fixed contact 1223. The second transition moving contact 1221 is connected to the second vacuum interrupter 1112, the third transition stationary contact 1222 is connected to the main contact unit 13, and the fourth transition stationary contact 1223 is connected to the transition resistance unit 14. Specifically, the second transition contact 1221 is connected to the other end of the second vacuum interrupter 1112, which is opposite to the end fixed to the first mounting plate 1 a.

The third transition contact 123 includes a third transition moving contact 1231, a fifth transition fixed contact 1232, and a sixth transition fixed contact 1233. The third transition moving contact 1231 is connected to the third vacuum interrupter 1121, the fifth transition stationary contact 1232 is connected to the main contact unit 13, and the sixth transition stationary contact 1233 is connected to the transition resistance unit 14. Specifically, the third transition movable contact 1231 is connected to the other end of the third vacuum interrupter 1121, which is opposite to the end fixed to the first mounting plate 1 a.

The fourth transition contact 124 includes a fourth transition contact 124, a seventh transition fixed contact 1242, and an eighth transition fixed contact 1243. The fourth transition moving contact 1241 is connected to the fourth vacuum interrupter 1122, the seventh transition stationary contact 1242 is connected to the main contact unit 13, and the eighth transition stationary contact 1243 is connected to the transition resistance unit 14. Specifically, the fourth transition contact 1241 is connected to the other end of the fourth vacuum interrupter 1122, which is opposite to the end fixed to the first mounting plate 1 a.

It should be noted here that, in the top view of the transition contact unit 12 shown in fig. 3, the four transition contacts are uniformly arranged on the circumference, but in the up-down direction, the four transition contacts are staggered on the first level and the second level. Specifically, the first transition contact 121 and the third transition contact 123 are disposed at a first level, and the second transition contact 122 and the fourth transition contact 124 are disposed at a second level, which is different from the first level. A first distance between the first transition contact 121 and the center point of the first mounting plate 1a is equal to a second distance between the third transition contact 123 and the center point of the first mounting plate 1 a. A third distance between the second transition contact 122 and the center point of the first mounting plate 1a is equal to a fourth distance between the fourth transition contact 124 and the center point of the first mounting plate 1 a. That is, the first transition contact 121 and the third transition contact 123 are symmetrically arranged at an angle of 180 degrees on the first horizontal circumference. The second transition contact 122 and the fourth transition contact 124 are symmetrically arranged at an angle of 180 degrees on a second horizontal circumference. The first transition contact group corresponding to the first vacuum interrupter unit 111 is composed of the first transition contact 121 and the third transition contact 123, and the second transition contact group corresponding to the second vacuum interrupter unit 112 is composed of the second transition contact 122 and the fourth transition contact 124. Obviously, the first transition contact group and the second transition contact group are also symmetrically arranged in the switching core, so that the stress of each switching mechanism of the vacuum on-load tap-changer in the operation process can be further ensured to be uniform.

In addition, the first transition static contact 1212 and the second transition static contact 1213 are mounted on a first insulating support bar 1210 arranged in the vertical direction, the third transition static contact 1222 and the fourth transition static contact 1223 are mounted on a second insulating support bar 1220 arranged in the vertical direction, the fifth transition static contact 1232 and the sixth transition static contact 1233 are mounted on a third insulating support bar 1230 arranged in the vertical direction, and the seventh transition static contact 1242 and the eighth transition static contact 1243 are mounted on a fourth insulating support bar 1240 arranged in the vertical direction. The first transition moving contact 1211, the second transition moving contact 1221, the third transition moving contact 1231, and the fourth transition moving contact 1241 are all disposed on the rotating shaft 120 at the center of the switching core.

The transition movable contact in the transition contact unit 12 is turned in a shaft-rotating manner to make point contact with the corresponding transition stationary contact. The dynamic transition contact and the corresponding static transition contact are not easy to be damaged due to long-term large-area contact friction. Therefore, each transition contact provided by the application has high arc extinguishing energy, for example, the arc extinguishing capacity can reach more than 500 times, and the arc can be cut off through the transition contact after the corresponding vacuum arc extinguishing fails, so that the reliability of the tap changer is further ensured.

Continuing to refer to fig. 4, it is a top view of the main contact unit 13. In some embodiments, the switching core further comprises a second mounting plate 1b located below the first mounting plate 1a and concentrically arranged with the first mounting plate 1 a. Specifically, a first surface of the second mounting plate 1b is opposite to a second surface of the first mounting plate 1a, and the second surface of the first mounting plate 1a is a surface opposite to the first surface of the first mounting plate 1 a. The first surface of the second mounting disk 1b is constituted by a third region and a fourth region that are symmetrical about the second axis cd. The main contact unit 13 includes a first main contact group 131 located on the third region and a second main contact group 132 located on the fourth region. The first main contact group 131 and the second main contact group 132 are symmetrical about said second axis cd.

The first main contact group 131 includes three stationary main contacts 1310, 1312, 1313 disposed at equal intervals on the circumferential edge of the third region of the second mounting plate 1b, and a movable main contact 1311 fixedly connected to the stationary main contact 1310 at one end and switching between the stationary main contacts 1312, 1313 at the other end. The second main contact group 132 includes three stationary main contacts 1320, 1322, 1323 disposed at equal intervals on the circumferential edge of the third region of the second mounting disk 1b, and a movable main contact 1321 having one end fixedly connected to the stationary main contact 1320 and the other end switching between the stationary main contacts 1322, 1323. The stationary main contacts 1312 and 1313 are connected to a first region of the mounting surface of the first mounting plate 1a, and the stationary main contacts 1322 and 1323 are connected to a second region of the mounting surface of the first mounting plate 1 a. A stationary main contact 1310 is connected to the first tap side output and a stationary main contact 1320 is connected to the second tap side output.

Because in this application, main contact unit only comprises two sets of main contact group that the symmetry set up, the effectual insulating margin that increases between each contact on the second mounting disc, and the atress is also more even simultaneously.

Fig. 5 is a top view of the transition resistance unit 14. In some embodiments, the switching core further comprises a third mounting plate 1c located below the second mounting plate 1b and concentrically arranged with the second mounting plate 1 b. Specifically, a first surface of the third mounting plate 1c is opposite to a second surface of the second mounting plate 1b, and the second surface of the second mounting plate 1b is a surface opposite to the first surface of the second mounting plate 1 b. . The first surface of the third mounting plate 1c is constituted by a fifth region and a sixth region which are symmetrical about the third axis ef. The excessive resistance unit 14 includes a first excessive resistance group 141 on the fifth region and a second excessive resistance group 142 on the sixth region. Wherein the first and second over-resistance groups 141 and 142 are symmetrical about the third axis ef.

In some embodiments, first set of transition resistances 141 includes first transition resistance 1411 and second transition resistance 1412, and second set of transition resistances 142 includes third transition resistance 1421 and fourth transition resistance 1422. A first end of the first transition resistor 1411 is connected to a second transition stationary contact 1213 in the first transition contact 121, and the other end is connected to a main stationary contact 1310 in the first main contact group 131; a first end of the second transition resistor 1412 is connected to the fourth transition stationary contact 1223 in the second transition contact 122, and the other end is connected to the main stationary contact 1310 in the first main contact group 131; a first end of the third transition resistor 1421 is connected to the sixth transition stationary contact 1233 in the third transition contact 121, and the other end is connected to the main stationary contact 1320 in the second main contact group 131; a first end of the fourth transition resistor 1422 is connected to the eighth transition stationary contact 1243 of the fourth transition contact 124, and the other end is connected to the main stationary contact 1320 of the second main contact group 132.

With continued reference to FIG. 1, the switching core also includes a rotating shaft 15 and a snap mechanism 16. The rotating shaft 15 sequentially passes through the center of the upper surface of the third mounting plate 1c, the center of the upper surface of the second mounting plate 1b, and the center of the upper surface of the first mounting plate 1a and then extends to the upper side of the first mounting plate 1 a. A snap mechanism 16 is provided at the bottom of the third mounting plate 1c, the snap mechanism 16 comprising a spring member by which the energy released is brought to rotate the rotation shaft 15. The rotation of the rotating shaft 15 drives the first mounting plate 1a, the second mounting plate 1b, and the third mounting plate 1c to rotate correspondingly, so as to drive the first vacuum arc-extinguishing unit 111, the second vacuum arc-extinguishing unit 112, the transition contact unit 12, and the main contact unit 13 to perform corresponding switching actions.

In addition, the application also provides a vacuum on-load tap-changer, which comprises the switching core provided according to any embodiment of the application, and a tap selector positioned below the switching core. The central rotating shaft of the tapping selector is connected with the rotating shaft of the switching core through a shaft sleeve. The tap selector includes a first tap selection unit 201 disposed corresponding to the first vacuum arc extinguishing unit 111, and a second tap selection unit 202 disposed corresponding to the second vacuum arc extinguishing unit 112. The tapping selector is shown in fig. 6, and includes a rotating shaft 21, an insulating support 22, a movable contact 23, a stationary contact 24, and a polarity converter 25.

The transmission shaft 21 is arranged at the center of the tapping selector, and rotates to drive a moving contact on the tapping selector to act, so that pre-selection of odd-even gear shifting is realized. The insulating supports 22 are arranged at the edge of the tapping selector, and each insulating support is provided with 4 fixed contacts for supporting and fixing. The moving contact 23 is arranged on the transmission shaft 21 and connected with the inner conductor of the rotating shaft 21, so that the pre-connection of the tap selector gear is realized. The static contacts 24 are arranged on the insulating support, two of the 4 static contacts correspond to the first switching mechanism and the second switching mechanism in the switching core, the 4 static contacts are divided into an upper unit and a lower unit, and each unit comprises an even-numbered stage static contact and an odd-numbered stage static contact which are used for connecting the tapping selector with the voltage regulating coil of the converter transformer. The polarity converter 25 is arranged on the side of the tapping selector to realize polarity conversion of the on-load tapping switch.

In addition, in some embodiments, the vacuum on-load tap-changer further comprises a potential resistance unit and an operating mechanism. The power grid resistance unit is positioned below the tapping selector (the power grid resistance unit is close to one end of the tapping selector, which is far away from the switching core), is sequentially connected and consists of a potential resistor and a potential switch, and is used for limiting the suspension potential discharge in the polarity conversion process of the on-load tapping switch; the operating mechanism comprises a control mechanism box, a motor, a transmission shaft and a gear box which are connected in sequence and used for driving the switching core and the tapping selector to execute corresponding switching actions.

In the description herein, references to the description of "some embodiments," "other embodiments," "desired embodiments," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, a schematic description of the above terminology may not necessarily refer to the same embodiment or example.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.