WO2020098750A1

WO2020098750A1 - High-voltage isolation transformer

Info

Publication number: WO2020098750A1
Application number: PCT/CN2019/118525
Authority: WO
Inventors: 郑健超; 张升; 刘远; 王成昊; 魏晓光; 贺之渊; 孙泽来
Original assignee: 全球能源互联网研究院有限公司; 国家电网有限公司
Priority date: 2018-11-14
Filing date: 2019-11-14
Publication date: 2020-05-22
Also published as: CN109599258B; CN109599258A

Abstract

The present application provides a high-voltage isolation transformer, comprising at least one sub-transformer. Where there is one sub-transformer, the high-voltage isolation transformer is equivalent to the sub-transformer; and where there are multiple sub-transformers, the multiple sub-transformers are connected in a cascade manner, and the sub-transformers are all connected to a voltage sharing device in parallel.

Description

High voltage isolation transformer

This application requires the priority of the Chinese patent application filed with the Chinese Patent Office and the application number 201811351232.6 on November 14, 2018. The entire contents of this application are incorporated by reference in this application.

Technical field

This application relates to the field of high-voltage power transmission, such as a high-voltage isolation transformer.

Background technique

The power transformer is one of the most commonly used equipment in the power system. It is mainly used for voltage conversion between different voltage levels, power transmission in the power system, and current conversion in systems with different transmission capacities. However, as far as the power transformer itself is concerned, it is very conventional. . However, with the development of current power technology, especially the development of flexible AC transmission and high-voltage DC transmission, the function of power transformers has been expanded, not only to the power transmission of the power system, but also to many other special occasions, such as for certain critical power The auxiliary power supply of the equipment requires these transformers to have the function of power output and high reliability and high voltage isolation.

In order to achieve voltage isolation and provide the necessary main insulation, the oil-immersed transformers are basically used for the transformers above 35kV currently used in the electric power field. For 35kV and below transformers, dry-insulated transformers, oil-insulated transformers and gas-insulated transformers are used. For some special high-voltage applications, especially power electronic equipment in the field of flexible AC transmission and DC equipment in the field of high-voltage large-capacity DC transmission, oil-free design is required for power equipment, but for high voltages higher than 35kV voltage level System, power transformers rarely have dry insulation structure. If oil-free design is required, the current conventional power transformer cannot meet the needs of engineering applications. Based on conventional design methods, at voltage levels higher than 35kV, dry-type transformers have a technical bottleneck, and the problem of partial discharge at high voltages has not been solved.

In view of the current voltage systems of hundreds of kilovolts and above, how to avoid the use of oil-immersed and gas-filled insulation becomes a design difficulty. For oil-immersed solutions, there is a risk of fire, especially high-voltage large-capacity transformers, which have large internal oil storage It is necessary to configure the oil storage tank and the oil guide groove after the transformer oil leakage, and if necessary, an explosion-proof structure needs to be set. The transformer design and operation and maintenance are complicated, and the reliability is relatively low. For the gas-filled transformer, although the insulation performance is good, and it is easy to avoid the partial discharge of the transformer at high voltage, it is not easy to cause a fire, but the transformer seal design requirements are high, and there is a risk of air leakage under long-term operating conditions, and the operation and maintenance are difficult.

The design of the dry-type transformer provided by the invention patent with application number 201180025143.2 includes one or more winding assemblies assembled to the iron core. Each winding includes high-voltage and low-voltage windings. In each high-voltage low-voltage winding, an insulating resin jacket is included Package low-voltage and high-voltage windings. This typical dry-type transformer is generally suitable for three-phase transformers, the voltage level is basically 35kV, and partial discharge is difficult to control. If it is extended to a voltage level above 35kV, there is currently no mature product application. The insulation design of conventional dry-type transformers is mainly focused on winding insulation. Although the invention patent of 201280007879.1 provides a slightly different winding insulation design method from the conventional winding design, it is also based on epoxy resin insulation optimization design, which also exists. The voltage level is limited and not conducive to winding heat dissipation.

Summary of the invention

In order to avoid the situation that the partial discharge is difficult to control, the voltage level is difficult to expand, and is not conducive to the heat dissipation of the winding in the above related technology, the present application provides a high-voltage isolation transformer, including at least one sub-transformer; Equivalent to sub-transformers; in the case of multiple sub-transformers, multiple sub-transformers are connected in cascade form, each sub-transformer is connected in parallel with a voltage equalizing device, the high-voltage isolation transformer provided by this application avoids the situation that partial discharge is difficult to control, and the voltage The level can be extended to hundreds of kilovolts and above, which is conducive to the cooling of the winding.

A high-voltage isolation transformer provided by the present application includes at least one sub-transformer; when there is one sub-transformer, the high-voltage isolation transformer is equivalent to the sub-transformer; when there are multiple sub-transformers, multiple sub-transformers Connected in a cascade connection, each sub-transformer is connected in parallel with a voltage equalizing device.

BRIEF DESCRIPTION

FIG. 1 is a topological structure diagram of a high-voltage isolation transformer according to an embodiment of the present application;

2 is a topological structure diagram of a pressure equalizing device in an embodiment of the present application;

3 is a schematic diagram of a first wiring form of a neutron transformer according to an embodiment of the present application;

4 is a schematic diagram of a second wiring form of a neutron transformer according to an embodiment of the present application;

5 is a schematic diagram of a third wiring form of a neutron transformer according to an embodiment of the present application;

6 is a perspective view of the physical structure of a neutron transformer according to an embodiment of the present application;

7 is a top view of the physical structure of a neutron transformer according to an embodiment of the present application;

8 is a schematic diagram of a neutron transformer iron core assembly according to an embodiment of the present application;

9 is a structural diagram of a winding sleeve in an embodiment of the present application;

10 is a first structural diagram of a high-voltage isolation transformer according to an embodiment of the present application;

11 is a second structural diagram of a high-voltage isolation transformer according to an embodiment of the present application;

12 is a third structural diagram of a high-voltage isolation transformer according to an embodiment of the present application;

In the picture, 1. Sub-transformer, 2. Voltage equalizing device, 3. Primary winding, 4. Secondary winding, 5. First winding bushing, 6. Second winding bushing, 7. First bracket, 8. Second bracket, 9, first current-carrying busbar, 10, second current-carrying busbar, 11, iron core assembly, 12, first terminal sleeve, 13, second terminal sleeve, 14, first terminal , 15, second terminal, 16, first iron core pull plate, 17, first iron core clamp, 18, second iron core clamp, 19, first body insulation, 20, first creeping insulation, 21 2. Second surface insulation, 22, connecting busbar, 23, support insulator, 24, voltage-sharing shield, 3 ', primary parallel winding, 4', secondary parallel winding, 5 ', compensation winding.

detailed description

The high-voltage isolation transformer provided by the embodiments of the present application is based on a solid insulation structure and adopts a unique structure form and an insulation structure, which can realize a dry structure design in the voltage range of tens of kilovolts to hundreds of kilovolts, and at the same time can realize different voltages No partial discharge design under the rating. The high-voltage isolation transformer provided by the embodiments of the present application is composed of one sub-transformer with a solid insulation structure or a cascade of multiple sub-transformers with a solid insulation structure. The number of sub-transformers depends on the voltage level of the application. Flexible design from tens of kV to hundreds of kV. Each sub-transformer includes high and low voltage winding structure, iron core, supporting structure and high voltage shielding structure of dry insulation structure, in which the combination of high voltage winding and iron core is set to realize the basic transformation of transformer, power transmission and voltage isolation, supporting structure It is set to realize the combination and structural support of the transformer and provide stable structural strength that meets the requirements of application conditions. The high-voltage shielding structure is used to suppress corona discharge when the transformer is applied under high-voltage conditions.

Compared with many technical limitations of traditional dry-type transformers such as insulation isolation, partial discharge suppression, low application voltage level, and inflexible extension applications, the high-voltage isolation transformer provided by the embodiments of the present application circumvents the design limitations of traditional dry-type transformers. The field strength of the transformer under high-voltage conditions is improved, the design structure and material performance of the solid insulation are improved, both the voltage level of the transformer and the partial discharge suppression are improved.

An embodiment of the present application provides a high-voltage isolation transformer, which includes at least one sub-transformer.

In the case of one sub-transformer, the high-voltage isolation transformer of the embodiment of the present application is equivalent to the sub-transformer.

In the case of multiple sub-transformers, multiple sub-transformers are connected in cascade (that is, the output winding of the front-stage sub-transformer is connected to the input winding of the post-stage sub-transformer), as shown in FIG. 1 includes a primary winding 3 and a secondary winding 4, each sub-transformer is a transformer with a transformation ratio of 1: 1 or 1: n or n: 1, and each sub-transformer has a voltage isolation capability, that is, an insulation withstand capability. In the case of multiple sub-transformers in cascade, under the effect of a certain voltage level, in order to ensure that the sub-transformers at all levels can withstand voltage evenly, each sub-transformer is connected in parallel with the voltage equalizing device 2. The core of the high-voltage isolation transformer of the embodiment of the present application lies in the sub-transformer. The transmission characteristics and insulation characteristics of the sub-transformers directly determine the characteristics of the entire high-voltage isolation transformer, and the voltage equalization device has a better improvement in the voltage distribution characteristics of the entire high-voltage isolation transformer.

The high-voltage DC circuit breaker and other power electronic equipment at high potential (with a voltage not lower than 1kV) obtain power from the outside of the equipment to supply high-voltage isolation transformers. The input side of the high-voltage isolation transformers can range from power frequency to hundreds of thousands Hertz AC power supply, the sub-transformer has an independent structure of insulation isolation at high voltage, the output end of each sub-transformer is used as the input end of the next sub-transformer, and the low-potential power is sent to the high-potential power equipment by way of stepwise connection .

The high-voltage isolation transformer has better voltage isolation characteristics under the effect of high voltage, and can be auxiliary configured with a voltage equalizing device with a high voltage equalizing effect; according to the high-voltage isolation transformer under different voltage application conditions such as AC and DC, the voltage equalizing device can It is composed of a voltage-equalizing resistor and voltage-equalizing capacitor that can withstand greater than or equal to the withstand voltage of the sub-transformer (as shown in Figure 2), or it can be a separate voltage-equalizing resistor or voltage-equalizing capacitor.

The primary and secondary windings of the sub-transformer cooperate with the iron core to form a basic transformer electrical structure (as shown in Figure 3). Based on the requirements of different applications of the high-voltage isolation transformer, the sub-transformer can also use the primary winding or the secondary winding to add compensation windings In the extended wiring form, the compensation winding 5 'is located on the same core position side as the primary winding 3 or the secondary winding 4 (as shown in Figure 4). The sub-transformer can also use the extended connection form of the primary and secondary windings connected in parallel as shown in FIG. 5, the primary winding 3 and the secondary winding 4 are arranged on the iron core column, and the primary parallel winding 3 'and the secondary side are added at the same time. The parallel winding 4 ', and the primary and secondary windings are electrically connected in parallel with the primary and secondary parallel windings.

The first-stage sub-transformer in FIG. 1 serves as the input terminal of the low-voltage side, and the last-stage sub-transformer serves as the output terminal of the high-voltage side. As shown in FIGS. 6 and 7, the sub-transformer includes the first winding sleeve 5, the iron core assembly 11, The first bracket 7 and the second bracket 8 are the support structure of the sub-transformer, and effectively integrate multiple components of the sub-transformer into a structural whole.

The above-mentioned sub-transformer further includes a second winding bushing 6 and a current-carrying busbar. The current-carrying busbar realizes the connection between the connection terminals and realizes electrical flow.

The second winding sleeve 6 has the same structure as the first winding sleeve 5, as shown in FIGS. 6 and 9, the winding sleeve is the core component of the sub-transformer insulation isolation, and the first winding sleeve 5 includes the first primary side Winding, first secondary winding, first body insulation 19, first creeping insulation 20, second creeping insulation 21, first terminal 14, second terminal 15, first terminal sleeve 12 and second terminal sleeve 13.

The first primary winding and the first secondary winding are toroidal coils made of conductive materials. The core assembly 11 is a necessary magnetic component of the sub-transformer and a supporting body in the form of a sub-transformer structure. As shown in FIG. 8, the iron core assembly 11 includes an iron core, a first iron core pull plate 16, a second iron core pull plate, a first iron core clamp 17 and a second iron core clamp 18.

The iron core is a rectangular iron core. The rectangular iron core includes two long sides and two short sides. The rectangular iron core is a multi-layered component, generally a silicon steel sheet, or other materials that are suitable for the manufacture of transformer iron cores. The first iron core pull plate 16, the second iron core pull plate, the first iron core clamp 17 and the second iron core clamp 18 form a whole. This structure must not only meet the electromagnetic characteristics of the iron core required by the transformer, but also ensure sufficient mechanical strength. The first iron core pull plate 16 is attached to the upper surface of the iron core, and the second iron core pull plate is attached to the lower surface of the iron core; the first bracket 7 and the second bracket 8 are located on the two short sides of the iron core, respectively The lower side of the core is set to support the iron core; the first iron core clamp 17 and the second iron core clamp 18 are located on the upper sides of the two short sides of the iron core respectively, and are set as fixed iron cores; the first winding sleeve 5 sets On one of the two long sides of the core.

As shown in FIGS. 6 and 9, the first primary winding and the first secondary winding have a circular ring structure, the first primary winding is located inside the first secondary winding, and the first secondary winding is insulated by the first body 19 1. The first creeping insulation 20 and the second creeping insulation 21 are wrapped to achieve high voltage isolation between the first primary winding and the first secondary winding. The first body insulation 19 is located in the middle of the first secondary winding, and the first creeping insulation 20 and the second creeping insulation 21 are located at both ends of the first secondary winding, respectively.

The first terminal sleeve 12 is sleeved outside the first terminal 14, the second terminal sleeve 13 is sleeved outside the second terminal 15, the bottom of the first terminal 14 passes through the outer surface of the first body insulation 19 and is wrapped in The first port of the first secondary winding inside the first body insulation 19 is connected, the bottom of the second terminal 15 passes through the outer surface of the first body insulation 19 and the first secondary winding wrapped inside the first body insulation 19 Is connected to the second port, and the top of the first terminal 14 and the top of the second terminal 15 are respectively located above the first body insulation 19.

The second winding sleeve 6 includes a second primary winding, a second secondary winding, a second body insulation, a third creeping insulation, a fourth creeping insulation, a third terminal, a fourth terminal, a third terminal bushing and The fourth terminal sleeve.

The second primary winding and the second secondary winding have a circular ring structure. The second primary winding is located inside the second secondary winding. The second secondary winding is insulated by the second body, the third creeping insulation and the fourth Along the surface insulation package, the second body insulation is located in the middle of the second secondary winding, and the third and fourth surface insulations are located at both ends of the second secondary winding, respectively.

The third terminal sleeve is sheathed outside the third terminal, the fourth terminal sleeve is sheathed outside the fourth terminal, the bottom of the third terminal passes through the outer surface of the second body insulation and is wrapped inside the second body insulation The first port of the second secondary winding is connected, the bottom of the fourth terminal passes through the outer surface of the second body insulation and is connected to the second port of the second secondary winding wrapped inside the second body insulation, and the third connection The top of the terminal and the top of the fourth terminal are respectively located on the upper portion of the second body insulation.

In the case of a single current-carrying busbar, the first terminal 14 and the third terminal are connected through the first current-carrying busbar 9 (the first primary winding and the second primary winding can be connected in parallel, corresponding to FIG. 3 Connection form), or the second connection terminal 15 and the fourth connection terminal are connected through the second current-carrying busbar 10 (a parallel connection of the first secondary winding and the second secondary winding can be realized, corresponding to the connection form of FIG. 4).

In the case of two current-carrying bus bars, the first terminal 14 and the third terminal are connected through the first current-carrying bus 9, and the second terminal 15 and the fourth terminal are connected through the second current-carrying bus 10 The connection realizes the parallel connection of the first primary winding and the second primary winding and the parallel connection of the first secondary winding and the second secondary winding, corresponding to the wiring form of FIG. 5.

The first creeping insulation 20, the second creeping insulation 21, the third creeping insulation and the fourth creeping insulation are of an umbrella structure; and the first body insulation 19, the first creeping insulation 20, the second creeping insulation 21, and the second creeping insulation 3. The third creeping insulation and the fourth creeping insulation are made of solid resin materials.

The high-voltage isolation transformer provided in the embodiments of the present application further includes a post insulator for supporting the sub-transformer. The voltage equalizing device is disposed inside the post insulator. The post insulator and the equalizing device form a main support structure of the high-voltage isolation transformer.

The number of the above voltage equalizing devices is less than or equal to the number of post insulators, that is, each post insulator may be provided with a voltage equalizing device, or some of the post insulators may be provided with a voltage equalizing device, and the rest of the post insulators are not provided with a voltage equalizing device. , Determined according to the actual situation.

As shown in FIG. 11, the sub-transformer in the high-voltage isolation transformer provided by the embodiment of the present application is provided with a voltage equalizing shield 24 outside.

The sub-transformer can meet the application requirements of any voltage level by adjusting the winding sleeve size according to the transformer application and voltage level. In the case of high voltage, the diameter and length of the winding sleeve can be increased, and the number of surface umbrella structures can be increased to meet the requirements of increasing voltage levels. In the case of low voltage, by reducing the diameter and length of the winding sleeve and reducing the number of surface umbrella structures, it can meet the requirements of reducing the voltage level.

Based on the sub-transformer, through multiple combinations of multiple sub-transformer structures, it can meet the extended application requirements of various voltage levels. Multiple sub-transformers can be arranged one by one in the vertical direction, and multiple sub-transformers can also be arranged in a combination of horizontal and vertical directions, from the first-stage sub-transformer located at the bottom of the high-voltage isolation transformer to the last-stage sub-transformer located above the high-voltage isolation transformer A plurality of sub-transformers are connected in sequence through conductive structural members, which are connected copper bars.

The single-row combination form of the sub-transformers is shown in Figure 10. The adjacent sub-transformers are connected by connecting copper bars. The sub-transformers are supported by pillar insulators and voltage equalizers to form a structural whole. Four adjacent pillar transformers are connected by four pillar insulators. Support, the four pillar insulators can be equipped with voltage equalizing devices, or one, two or three pillar insulators can be equipped with voltage equalizing devices, that is, the number of voltage equalizing devices provided inside the four pillar insulators is more flexible, Set according to actual needs. The voltage equalizing device is equipped with resistance and capacitance in the insulating sleeve, and is filled with insulating material in the sleeve. For high-voltage transformers in high-voltage applications, corona discharge suppression at high voltage needs to be considered. Therefore, it is necessary to design a corresponding voltage-sharing shield (see Figure 11) to improve the electric field and suppress corona discharge at high voltage.

The high-voltage isolation transformer can also have other application structure forms. As shown in FIG. 12, the sub-transformer is arranged in a double-row structure, supported and fixed by the pillar insulator 23 and the voltage equalizing device 2, and electrically connected by the connecting bus bar 22, and A voltage equalizing shield 24 is arranged outside the high-voltage isolation transformer.

In terms of application structure, the high-voltage isolation transformer provided by the embodiments of the present application is not limited to a supporting fixed structure, and a suspension fixed structure may also be used. The post insulator 23 of the structures shown in FIGS. 10 to 12 may be changed to suspension The insulator can be suspended and fixed, and the number of suspended sub-transformers is different according to different voltage levels.

The high-voltage isolation transformers provided in the embodiments of the present application are different from the conventional dry-type transformers of 35 kV and below common in the market in terms of material selection, structural form and manufacturing process. In addition to all the functional characteristics of dry-type transformers, the dry-type transformers described in this application also have many advantages such as flexible expansion of high-voltage applications, compact structure, excellent fire and explosion-proof performance, etc., and can also be flexibly expanded to voltage levels above 35kV Compared with conventional dry-type transformers, it has the advantages of higher insulation strength, low partial discharge suppression, low noise and high heat dissipation. The embodiments of the present application can be used not only for power transmission, but also as an external energy supply source for high-voltage passive power equipment, with dual functions of potential isolation and energy transmission.

The high-voltage isolation transformer provided in this application includes at least one sub-transformer; in the case of one sub-transformer, the high-voltage isolation transformer is equivalent to the sub-transformer; in the case of multiple sub-transformers, multiple sub-transformers are connected in cascade, each A sub-transformer is connected in parallel with a voltage equalizing device. The high-voltage isolation transformer provided by this application avoids the situation that partial discharge is difficult to control. The voltage level can be extended to hundreds of kilovolts and above, and is conducive to heat dissipation of the winding.

This application can effectively reduce the difficulty of transformer insulation design and the difficulty and volume of manufacturing process. It has high insulation withstand strength and low field strength distribution. At the same time, it can effectively suppress partial discharge and realize low partial discharge design of transformers, with voltages above 100 kilovolts. The level of partial discharge does not exceed 50pC.

The sub-transformer in this application adopts a flexible split design of the winding sleeve and the iron core assembly, which can flexibly adjust the outlet position of the terminal block according to the needs of the application scenario, to achieve flexible wiring between the sub-transformers, the isolation transformer as a whole and the outside.

The application can achieve the suppression of corona discharge in a wide voltage range, and at the same time has the advantages of small structural size, high mechanical strength, flexible installation and the like.

The sub-transformer in this application is provided with an insulated shield, which can achieve effective insulation isolation in a compact space.

The overall structure of the high-potential isolation transformer provided by the patent of this application is flexible in layout. It can be either fixed or suspended, which can be flexibly arranged according to the requirements of the application scenario.

Claims

A high-voltage isolation transformer includes at least one sub-transformer; in the case of one sub-transformer, the high-voltage isolation transformer is equivalent to the sub-transformer; in the case of multiple sub-transformers, multiple sub-transformers are connected in cascade, Each sub-transformer is connected in parallel with a voltage equalizing device.
The high-voltage isolation transformer according to claim 1, wherein the sub-transformer includes a first winding bushing, an iron core assembly, a first bracket, and a second bracket; the first winding bushing includes a first primary winding, The first secondary winding, the first body insulation, the first creeping insulation, the second creeping insulation, the first terminal, the second terminal, the first terminal sleeve and the second terminal sleeve.
The high-voltage isolation transformer according to claim 2, wherein the iron core assembly includes an iron core, a first iron core pull plate, a second iron core pull plate, a first iron core clamp, and a second iron core clamp.
The high-voltage isolation transformer according to claim 3, wherein the iron core is a rectangular iron core, the rectangular iron core includes two long sides and two short sides; the first iron core pull plate is attached to the The upper surface of the iron core, the second iron core pull plate is attached to the lower surface of the iron core; the first bracket and the second bracket are respectively located under the two short sides of the iron core , Set to support the iron core; the first iron core clip and the second iron core clip are respectively located on the upper sides of the two short sides of the iron core, and are set as fixed iron cores; the first The winding sleeve is sleeved on one of the two long sides of the iron core.
The high-voltage isolation transformer according to claim 2, wherein the first primary winding and the first secondary winding have a circular ring structure, the first primary winding is located inside the first secondary winding, and the first A secondary winding is wrapped by a first body insulation, a first creeping insulation and a second creeping insulation, the first bulk insulation is located in the middle of the first secondary winding, the first creeping insulation and the second creeping insulation Are located at both ends of the first secondary winding; the first terminal sleeve is sheathed outside the first terminal, the second terminal sleeve is sheathed outside the second terminal, the first The bottom of the connection terminal is connected to the first port of the first secondary winding wrapped inside the insulation of the first body through the outer surface of the insulation of the first body, and the bottom of the second connection terminal is passed through the The outer surface of the first body insulation is connected to the second port of the first secondary winding wrapped inside the first body insulation, and the top of the first terminal and the top of the second terminal Located on the upper portion of the first body insulation.
The high-voltage isolation transformer according to claim 5, the sub-transformer further includes a second winding bushing and a current-carrying busbar; the second winding bushing has the same structure as the first winding bushing, the The second winding sleeve includes a second primary winding, a second secondary winding, a second body insulation, a third creeping insulation, a fourth creeping insulation, a third terminal, a fourth terminal, a third terminal bushing and a first Four-terminal bushing.
The high-voltage isolation transformer according to claim 6, wherein the second primary winding and the second secondary winding have a circular ring structure, the second primary winding is located inside the second secondary winding, and the first The second secondary winding is wrapped by a second main insulation, a third creeping insulation and a fourth creeping insulation, the second main insulation is located in the middle of the second secondary winding, and the third creeping insulation and the fourth creeping insulation are located respectively Two ends of the second secondary winding; the third terminal sleeve is sheathed outside the third terminal, the fourth terminal sleeve is sheathed outside the fourth terminal, and the third terminal Is connected to the first port of the second secondary winding wrapped inside the second body insulation through the outer surface of the second body insulation, and the bottom of the fourth terminal passes through the first The outer surface of the two-body insulation is connected to the second port of the second secondary winding wrapped inside the second body insulation, and the top of the third terminal and the top of the fourth terminal are located at Said second body insulating upper part.
The high-voltage isolation transformer according to claim 7, wherein, in the case where the current-carrying busbar is a single unit, the first terminal and the third terminal are connected through the first current-carrying busbar, Or the second connection terminal and the fourth connection terminal are connected by the second current-carrying busbar; in the case of two current-carrying busbars, the first terminal and the third The connection terminals are connected by a first current-carrying bus bar, and the second connection terminals and the fourth connection terminals are connected by a second current-carrying bus bar.
The high-voltage isolation transformer according to claim 7, wherein the first creeping insulation, the second creeping insulation, the third creeping insulation and the fourth creeping insulation are umbrella-shaped structures; the first body The insulation, the first creeping insulation, the second creeping insulation, the second body insulation, the third creeping insulation, and the fourth creeping insulation are made of solid resin materials.
The high-voltage isolation transformer according to claim 1, wherein the voltage equalizing device includes a voltage equalizing resistor and a voltage equalizing capacitor, or the voltage equalizing device includes a parallel voltage equalizing resistor and a voltage equalizing capacitor.
The high-voltage isolation transformer according to claim 1, further comprising a post insulator for supporting a sub-transformer, the voltage equalizing device is disposed inside the post insulator, the post insulator and the voltage equalizing device form the high-voltage isolation The main body supporting structure of the transformer; the number of the voltage equalizing devices is less than or equal to the number of the pillar insulators.
The high-voltage isolation transformer according to claim 1, wherein a voltage equalizing shield is provided outside the sub-transformer.
The high-voltage isolation transformer according to claim 1, wherein, in the case where there are a plurality of sub-transformers, the plurality of sub-transformers are arranged one by one in the vertical direction, or the plurality of sub-transformers are arranged in combination in the horizontal direction and the vertical direction. The sub-transformers are connected sequentially through conductive structural parts; the conductive structural parts are connected copper bars.