Selector and adjustable transformer for on-load tap changer

Abstract

The utility model relates to a selector for on-load tap changer, the selector includes: selector substrate, install the selector arm on the selector substrate, be equipped with movable contact on the selector arm, install a plurality of fixed contacts on the selector substrate, the fixed contact in a plurality of fixed contacts can be selectively contacted movable contact on the selector arm, wherein, a plurality of fixed contacts are configured respectively as integral fixed contact and are configured to be directly electrically connected with the tap of the regulating winding of adjustable transformer. In addition, the utility model further relates to an adjustable transformer.

Description

Technical Field

[0001] This utility model relates to a selector for an on-load tap changer and an adjustable transformer, wherein the on-load tap changer is used to perform uninterrupted load switching between different taps of the regulating winding of the adjustable transformer. Background Technology

[0002] In power transmission and distribution systems, adjustable transformers, as core power equipment, bear the crucial task of adjusting the output voltage in real time according to changes in grid load and voltage fluctuations. Their operational stability directly determines the quality and safety of the power grid. Adjustable transformers primarily achieve voltage regulation by changing the turns ratio of their windings, and in this process, on-load tap changers (OLTCs) play an indispensable role. OLTCs can switch between different winding taps of the adjustable transformer while it is operating under load, ensuring continuous and uninterrupted voltage regulation. This avoids the impact of power outages on industrial production and residential life, and they are widely used in transmission lines, substations, and large industrial enterprises.

[0003] An on-load tap changer typically includes a selector, an on-load switch, and an optional preselector. In some cases, an on-load tap changer may simply include a selector with N taps, each tap connected to a matching tap of the regulating winding of an adjustable transformer. Therefore, such an on-load tap changer has a position adjustment range of N positions, and the adjustable transformer including such an on-load tap changer has a voltage regulation range of N voltages. To extend the voltage regulation range of the adjustable transformer, a preselector may be provided in addition to the selector. The preselector can selectively connect the regulating winding of the adjustable transformer to the main winding of the adjustable transformer in the same or opposite directions. With the aid of the preselector, a portion of the main winding can be selectively disconnected or connected; that is, the portion of the main winding can be selectively connected or disconnected from the regulating winding.

[0004] However, to achieve electrical connection between the on-load tap changer selector and the regulating winding of the adjustable transformer, the fixed contact of the selector needs to be equipped with a conductive line with a tap, wherein a through hole can be provided for threaded fasteners (such as screws, bolt-nut assemblies, etc.). In this case, during assembly, it is necessary to manually establish the electrical connection between the conductive line and the fixed contact of the selector, and also manually establish the electrical connection between the conductive line and the regulating winding. Given the inherent limitations of the operating space inside the adjustable transformer, these connection requirements undoubtedly further increase the difficulty of the assembly operation. Utility Model Content

[0005] The objective of this invention is to provide a selector and an adjustable transformer for an on-load tap changer, thereby enabling the on-load tap changer to be installed in the adjustable transformer in a simple, efficient and / or reliable manner, and in particular, to achieve a direct electrical connection between the selector and the regulating winding of the adjustable transformer in a simple, efficient and / or reliable manner.

[0006] According to a first aspect of this application, a selector for an on-load tap changer is provided, the selector comprising: a selector base plate; a selector arm mounted on the selector base plate, the selector arm having a movable contact; and a plurality of fixed contacts mounted on the selector base plate, wherein a fixed contact among the plurality of fixed contacts can be selectively contacted by the movable contact on the selector arm, wherein the plurality of fixed contacts are each configured as an integral fixed contact and are configured for direct electrical connection with the tap of the regulating winding of an adjustable transformer.

[0007] In some embodiments, each fixed contact has a connection portion for electrically connecting a tap of an adjusting winding, the connection portion being configured as a crimping section and / or a soldering section of the fixed contact.

[0008] In some embodiments, the connection portion is configured as a connection portion without a through hole for the threaded part.

[0009] In some embodiments, a first portion of the plurality of fixed contacts extends from a first side of the selector substrate through a through-hole on the selector substrate to a second side of the selector substrate, and a second portion of the plurality of fixed contacts extends from the second side of the selector substrate through a through-hole on the selector substrate to the first side of the selector substrate.

[0010] In some embodiments, the plurality of fixed contacts are distributed within a circular outline.

[0011] In some embodiments, the selector further includes a support plate mounted to a selector substrate, the support plate having a hole pattern including predetermined receiving holes for guiding the plurality of fixed contacts accordingly.

[0012] In some embodiments, the hole pattern of the support plate includes two rows of receiving holes, wherein the first row of receiving holes is used to receive a fixed contact disposed on a first side of the selector substrate, and the second row of receiving holes is used to receive a fixed contact disposed on a second side of the selector substrate.

[0013] In some embodiments, the support plate is mounted to a sidewall of the selector substrate, and the longitudinal extension of the support plate is parallel to the longitudinal extension of the sidewall.

[0014] In some embodiments, the length of the contact section of each fixed contact from the support plate to the connection portion of the tap for electrically connecting the regulating winding is between 20 mm and 80 mm.

[0015] In some embodiments, the selector includes a first selector arm disposed on a first side of the selector substrate and a first driver for driving the first selector arm, and the selector includes a second selector arm disposed on a second side of the selector substrate and a second driver for driving the second selector arm, the first driver and the second driver being staggered about a common rotation axis, and fixed contacts being alternately disposed on the first side and the second side of the selector substrate.

[0016] According to a second aspect of this application, an adjustable transformer is provided, comprising: a main winding; an adjusting winding; and an on-load tap changer, the on-load tap changer including a selector and an on-load switch, characterized in that the selector is configured as a selector for an on-load tap changer according to some embodiments of this application.

[0017] In some embodiments, the plurality of fixed contacts of the selector extend from the selector to the regulating winding of the adjustable transformer and are crimped and / or welded to the corresponding taps. Attached Figure Description

[0018] The present application will now be described in more detail with reference to the accompanying drawings and specific embodiments. The schematic drawings are briefly described below:

[0019] Figure 1 A schematic diagram of an on-load tap changer according to a preferred embodiment of this application is shown;

[0020] Figure 2-5 Some example diagrams of selectors according to some embodiments of this application are shown;

[0021] Figure 6 A view of multiple fixed contacts configured as a single fixed contact is shown;

[0022] Figure 7 A schematic diagram of an adjustable transformer according to some embodiments of this application is shown. Detailed Implementation

[0023] The present application will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present application. However, it should be understood that the present application can be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure of the present application more complete and to fully illustrate the scope of protection of the present application to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide more additional embodiments.

[0024] In the various embodiments described, the same reference numerals or element names are used for the same elements, and the disclosure contained throughout the specification can be applied semantically to elements with the same reference numerals or element names. Furthermore, in the various embodiments, the number, implementation, and / or arrangement of elements are not limited to the examples shown, but other numbers, implementations, and / or arrangements can be selected according to actual needs.

[0025] In this document, spatial relation terms such as "up," "down," "left," "right," "front," "back," "high," and "low" are used to describe the relationship between one feature and another in the accompanying drawings. It should be understood that spatial relation terms include not only the orientation shown in the drawings but also different orientations of the device during use or operation. For example, when the device in the drawings is inverted, a feature previously described as "below" other features can now be described as "above" other features. The device can also be oriented in other ways (rotated 90 degrees or in other orientations), in which case the relative spatial relationships will be interpreted accordingly.

[0026] In this document, the term “A or B” includes both “A and B” and “A or B”, rather than exclusively including only “A” or only “B”, unless otherwise specified.

[0027] In this document, the terms "illustrative" or "exemplary" mean "serving as an example, instance, or illustration." Any implementation described herein by example is not necessarily to be construed as preferred or advantageous over other implementations. Moreover, this application is not limited to any stated or implied theory given in the foregoing technical field, background art, utility model content, or specific embodiments.

[0028] In this document, the term “substantially” means any minor variation caused by defects in design or manufacturing, tolerances of devices or components, environmental influences and / or other factors.

[0029] Additionally, terms such as “first,” “second,” etc., may be used in this document for reference purposes only and are not intended to be limiting. For example, unless the context clearly indicates otherwise, the words “first,” “second,” and other such numerical terms relating to structures or elements do not imply order or sequence.

[0030] Some embodiments of this application will now be described in more detail with reference to the accompanying drawings.

[0031] Figure 1A preferred embodiment of the on-load tap changer 10 is illustrated schematically. In this embodiment, the on-load tap changer 10 may include three selectors 20, three preselectors 40, and three on-load switching devices 60. Each selector 20, each preselector 40, and each on-load switching device 60 can be configured for a specific phase of the adjustable transformer. In other words, the on-load tap changer 10 may include multiple phase assemblies, each phase assembly including only one selector 20, only one preselector 40, and only one on-load switching device 60. Therefore, a single-phase configuration of the on-load tap changer 10 (for a single-phase adjustable transformer) may include only one selector 20, one preselector 40, and one on-load switching device 60. It should be noted that the preselector 40 in the on-load tap changer 10 is an optional configuration.

[0032] like Figure 1 As shown, each selector 20 (more precisely, its functional component) can be mounted on a selector substrate 21, each preselector 40 (more precisely, its functional component) can be mounted on a preselector substrate 41, and each on-load tap changer 60 (more precisely, its functional component) can be mounted on an on-load tap changer substrate 61. In some embodiments, each selector 20 can be integrated with a preselector 40. In other words, each selector substrate 21 can include not only selectors 20 but also preselectors 40. It should be noted that, for the three-phase adjustable transformer 30, each phase can be allocated at least two substrates, namely one selector substrate 21 and one on-load tap changer substrate 61, that is, the on-load tap changer 10 can include at least six substrates. In the illustrated embodiment, each phase can be allocated three substrates, namely one selector substrate 21, one preselector 41, and one on-load tap changer substrate 61, that is, the on-load tap changer 10 can include a total of nine substrates. In some embodiments, the individual substrates 21, 41, 61 may be arranged horizontally or vertically in different planes. For example, six or nine substrates (more precisely, the main surfaces of the substrates on which corresponding components are mounted) may be arranged horizontally or vertically side-by-side in six or nine planes. In some embodiments, the individual substrates 21, 41, 61 may be arranged horizontally or vertically in a common plane. For example, six or nine substrates may be oriented horizontally or vertically and arranged side-by-side in a plane. It should be understood that at least a portion of the substrates 21, 41, 61 may be integrated into a single substrate, thereby achieving a compact structure.

[0033] Each substrate 21, 41, 61 is preferably made of an insulating material, such as plastic or fiber-reinforced plastic (such as polyamide or a mixture of polyphthalamide and glass fiber). Each substrate 21, 41, 61 can be mounted onto and held together by the bracket 38. In some embodiments, each substrate 21, 41, 61 can be tightly connected to the strip structure of the bracket 38, for example, by means of threaded connection and / or snap-fit ​​fixing, or it can be first installed individually onto an auxiliary bracket 38 and then fixed to a common bracket via the auxiliary bracket, or it can be supported by spacers, injection-molded splicing tabs, or other auxiliary plate splicing methods. It should be understood that the specific installation and fixing method between each substrate 21, 41, 61 and the bracket 38 can be flexibly selected according to the actual installation space and working conditions, and is not limited to the present exemplary description.

[0034] Advantageously, the on-load tap changer 10 can be configured with a common drive shaft 17 capable of driving all selectors 20, all preselectors 40, and all on-load switches 60. In this embodiment, the drive shaft 17 can, for example, extend through all selector substrates 21, all preselector substrates 41, and all on-load switch substrates 61. The drive shaft 17 can be driven directly or indirectly, for example, via a transmission mechanism, by a drive module 33 (including a motor).

[0035] Figure 2-5 Some example diagrams of the selector 20 according to some embodiments of this application are shown. Figure 2 and 3 The views of selector 20 as seen from the first side are shown respectively. Figure 4 The view of selector 20 as seen from the second side is shown, and Figure 5 The view of selector 20 as seen from the end side is shown.

[0036] like Figure 2-5 As shown, the selector 20 includes a selector substrate 21, selector arms mounted on the selector substrate 21, and a plurality of fixed contacts 28. The selector substrate 21 may be configured as an insulating plate. The selector substrate 21 may be made of an insulating material, such as plastic or fiber-reinforced plastic (e.g., polyamide or a mixture of polyphthalic acid including glass fibers). The selector substrate 21 is exemplary to be generally rectangular and has a first side and an opposite second side.

[0037] like Figure 2-5As shown, the selector arm can be configured, for example, as a Maltese wheel. A movable contact can be provided on the selector arm, which can selectively contact one of the plurality of fixed contacts 28 as the selector arm rotates. Advantageously, a first portion of the fixed contacts 28 can extend from a first side of the selector substrate 21 through a through-hole in the selector substrate 21 to a second side of the selector substrate 21, and a second portion of the fixed contacts 28 can extend from the second side of the selector substrate 21 through a through-hole in the selector substrate 21 to a first side of the selector substrate 21. Thus, the plurality of fixed contacts 28 can be evenly distributed on both sides of the selector substrate 21.

[0038] like Figure 2-5 As shown, the selector 20 may include a first selector arm, such as a first Maltese wheel, and a first actuator (not shown) for driving the first selector arm, disposed on a first side of the selector base plate 21. The first actuator can be operated via a drive shaft 17 extending through the selector base plate 21. Here, the first actuator has a first protrusion that engages with the first Maltese wheel and intermittently drives the first Maltese wheel to rotate. Furthermore, the selector 20 may include a second selector arm, such as a second Maltese wheel, and a second actuator (not shown) for driving the second selector arm, disposed on a second side of the selector base plate 21, which can be operated via a drive shaft 17 extending through the selector base plate 21. The second actuator has a second protrusion that engages with the second Maltese wheel and intermittently drives the second Maltese wheel to rotate. The first and second actuators may be staggered about a common axis of rotation. The plurality of fixed contacts 28 may be alternately disposed on the first and second sides of the selector base plate 21. Advantageously, the plurality of fixed contacts 28 may be evenly distributed in a circular profile, for example. These fixed contacts 28 are in Figure 2 The middle is at least partially covered by the corresponding Maltese wheel, while Figure 3-5 This can be seen because the corresponding Maltese wheel has been removed.

[0039] The selector 20 may have a support plate 100 mounted to the selector substrate 21, more specifically, to a sidewall of the selector substrate 21, the longitudinal extension of which may be parallel to the longitudinal extension of the sidewall. The support plate 100 has a hole pattern including receiving holes for guiding the fixed contacts 28 through the selector 20. In the present embodiment, the hole pattern of the support plate 100 includes two rows of receiving holes extending parallel to each other, wherein a first row of receiving holes receives five fixed contacts 28 disposed on a first side of the selector substrate 21, and a second row of receiving holes receives four fixed contacts 28 disposed on a second side of the selector substrate 21.

[0040] The support plate 100 can be made of plastic or any other suitable material, especially as a single piece. The support plate 100 allows for efficient management of the fixed contacts 28. The predetermined sequence of the fixed contacts 28 and the predetermined spacing between them can be reliably guaranteed. The selector 20 can be easily installed into the on-load tap changer 10. Users can easily operate these fixed contacts 28.

[0041] To achieve the electrical connection between the selector 20 of the on-load tap changer 10 and the regulating winding 32 of the adjustable transformer 30, this application proposes a simple, efficient, and / or reliable connection method: directly establishing an electrical connection between an integrated fixed contact 28 and the regulating winding 32. This solution simplifies the connection path from a structural design perspective by eliminating traditional intermediate conductive lines, fundamentally reducing performance losses and failure risks caused by intermediate components. It also creates favorable conditions for compact equipment design and improved assembly efficiency.

[0042] Figure 6 A view of multiple fixed contacts 28 constituting an integral fixed contact is shown. These integral fixed contacts preferably use copper as the base material. Copper has excellent electrical conductivity and low resistivity, which effectively reduces energy loss during current transmission and ensures efficient electrical connection. Simultaneously, copper also possesses good mechanical strength and ductility, meeting the structural stability requirements of the fixed contacts 28 during installation and use, and resisting certain external impacts and deformations. To further enhance the performance of the fixed contacts 28, silver or gold plating is applied to the copper base material. Both silver and gold are highly conductive metals with strong corrosion resistance and oxidation resistance. Furthermore, the plating reduces the contact resistance on the contact surface, further optimizing current transmission efficiency and ensuring the reliability of the electrical connection.

[0043] To achieve a direct electrical connection between the integrated fixed contact 28 and the adjusting winding 32, each fixed contact 28 may have a connecting portion 282 for electrically connecting the adjusting winding 32 to a tap. This connecting portion 282 may be configured as a crimped section and / or a welded section of the fixed contact 28. In other words, the integrated fixed contact can be electrically connected to the adjusting winding 32 by crimping and / or welding without the need for an additional conductive line with a tap. Therefore, the connecting portion 282 may be configured without a through hole for threaded components.

[0044] Based on the aforementioned connection structure, the electrical connection between the integrated fixed contact 28 and the adjusting winding 32 can be achieved through crimping and / or welding. The crimping connection method applies pressure to the connection using a specialized crimping tool, ensuring a tight fit between the crimped section of the fixed contact 28 and the tap of the adjusting winding 32, forming a robust mechanical and stable electrical connection. The crimping process is simple to operate, requires no complex heating equipment, and is fast, making it suitable for batch assembly. Furthermore, crimped connections offer good shock and vibration resistance, maintaining connection stability during equipment operation and preventing loosening due to vibration. The welding connection method uses high-temperature heating to melt and fuse the contact surfaces of the welding section of the fixed contact 28 and the tap of the adjusting winding 32, forming a permanent metallurgical bond after cooling. This connection method has low contact resistance, excellent conductivity, and high connection strength, ensuring connection reliability during long-term operation, and is particularly suitable for applications with extremely high connection performance requirements. In practical applications, depending on specific usage requirements, working conditions, and production process requirements, one can flexibly choose to use crimping alone, welding alone, or a combination of crimping and welding to achieve the best connection effect.

[0045] Furthermore, to ensure a reasonable layout of the integrated fixed contact 28 within the equipment, while also guaranteeing its conductivity and structural stability, the length of the contact section of each fixed contact 28, extending from the support plate 100 to the connection portion 282 used for electrically connecting the regulating winding 32, is preferably between 20 mm and 80 mm. This length range is determined by considering multiple factors: if the length is too short (less than 20 mm), the installation space for the fixed contact 28 within the equipment may be too cramped, hindering precise docking with the regulating winding 32 tap. Additionally, insufficient conductive area in the contact section may result in high current density during high current transmission, leading to severe localized heating and affecting the safe operation of the equipment. If the length is too long (greater than 80 mm), it will increase the overall space occupied by the fixed contact 28, hindering the miniaturization design of the equipment. Furthermore, an excessively long contact section may reduce its structural rigidity, making it prone to vibration and deformation during equipment operation, affecting connection stability, and potentially increasing the total resistance of the current transmission path, leading to increased power loss. Therefore, a length range of 20 mm to 80 mm can achieve the best balance between ease of installation, conductivity, structural stability and equipment space utilization, ensuring that the integrated fixed contact can give full play to its technical advantages.

[0046] Figure 7 A schematic diagram of an adjustable transformer 30 according to some embodiments of this application is shown. The adjustable transformer 30 may include a main winding 31, an adjusting winding 32, and an on-load tap changer. The selector 20 of the on-load tap changer may be configured as the selector 20 for the on-load tap changer 10 described above. Figure 7 As shown, the plurality of fixed contacts 28 of the selector 20 can be configured as an integral fixed contact and extend from the selector 20 to the adjusting winding 32 of the adjustable transformer 30 and are crimped and / or welded to the corresponding taps.

[0047] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and not for limiting the scope of this application. The various embodiments disclosed herein can be combined in any way without departing from the spirit and scope of this application. Those skilled in the art should also understand that various modifications can be made to the embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A selector for an on-load tap changer, characterized in that, The selector (20) includes: Selector substrate (21); A selector arm is mounted on a selector base plate (21), and a movable contact is provided on the selector arm; A plurality of fixed contacts (28) are mounted on a selector base plate (21), wherein the fixed contacts among the plurality of fixed contacts can be selectively contacted by movable contacts on the selector arm, wherein the plurality of fixed contacts (28) are each configured as an integral fixed contact and are configured to be directly electrically connected to the tap of the regulating winding (32) of the adjustable transformer (30).

2. The selector for an on-load tap changer according to claim 1, characterized in that, Each fixed contact (28) has a connection portion (282) for electrically connecting the tap of the regulating winding (32), the connection portion being configured as a crimped section and / or a welded section of the fixed contact (28).

3. The selector for an on-load tap changer according to claim 2, characterized in that, The connecting part (282) is configured as a connecting part without a through hole for the threaded part.

4. The selector for an on-load tap changer according to any one of claims 1 to 3, characterized in that, The first portion of the plurality of fixed contacts extends from the first side of the selector substrate through a through hole on the selector substrate to the second side of the selector substrate, and the second portion of the plurality of fixed contacts (28) extends from the second side of the selector substrate through a through hole on the selector substrate to the first side of the selector substrate.

5. The selector for an on-load tap changer according to any one of claims 1 to 3, characterized in that, The plurality of fixed contacts are distributed within a circular outline.

6. The selector for an on-load tap changer according to any one of claims 1 to 3, characterized in that, The selector (20) also includes a support plate (100) mounted to the selector substrate (21), the support plate having a hole pattern including predetermined receiving holes for guiding the plurality of fixed contacts accordingly.

7. The selector for an on-load tap changer according to claim 6, characterized in that, The hole pattern of the support plate (100) includes two rows of receiving holes, wherein the first row of receiving holes is used to receive a fixed contact disposed on a first side of the selector substrate, and the second row of receiving holes is used to receive a fixed contact disposed on a second side of the selector substrate.

8. The selector for an on-load tap changer according to claim 6, characterized in that, The support plate (100) is mounted on one side wall of the selector substrate, and the longitudinal extension of the support plate (100) is parallel to the longitudinal extension of the side wall.

9. The selector for an on-load tap changer according to claim 6, characterized in that, The length of the contact section of each fixed contact (28) extending from the support plate (100) to the connection portion of the tap for electrically connecting the regulating winding (32) is between 20 mm and 80 mm.

10. The selector for an on-load tap changer according to any one of claims 1 to 3, characterized in that, The selector (20) includes a first selector arm () disposed on a first side of the selector substrate and a first driver for driving the first selector arm, and the selector (20) includes a second selector arm disposed on a second side of the selector substrate and a second driver for driving the second selector arm. The first driver and the second driver are staggered around a common rotation axis, and each fixed contact (28) is alternately disposed on the first side and the second side of the selector substrate (21).

11. Adjustable transformer, including: Main winding (31); Adjusting winding (32); and An on-load tap changer (10) comprising a selector (20) and an on-load switch, characterized in that the selector (20) is configured as a selector for an on-load tap changer according to any one of claims 1 to 10.

12. The adjustable transformer according to claim 11, characterized in that, The plurality of fixed contacts (28) of the selector (20) extend from the selector (20) to the regulating winding (32) of the adjustable transformer (30) and are crimped and / or welded to the corresponding taps.

Images