A novel bypass switch

Abstract

The application relates to a novel bypass switch, in particular to a bypass switch capable of realizing local control of each module at the secondary end. The bypass switch comprises a shell, a lock catch mechanism assembly and a conductive loop assembly installed in the shell; the conductive loop assembly comprises two static contacts and one moving contact; the lock catch mechanism assembly comprises a pull rod and an electromagnet, the upper end of the pull rod is connected with the moving contact, a closing spring is sleeved at the lower end of the pull rod, and a limiting part matched with a movement top rod of the electromagnet is arranged on the pull rod. A primary lock catch mechanism is adopted to replace a traditional three-stage unlocking structure. 1. A novel lock catch mechanism is used, the lock catch unlocking and closing speed is faster, the number of parts is smaller, and the cost is low; 2. The insulating pull rod can be lengthened, 28kV insulation withstand voltage to ground is realized, and the 10kV system level to ground is met; 3. The conductive main loop of the application is simplified into a three-section structure of static contact-moving contact-static contact, the conductive loop is shortened, the structure is simpler, and the cost of parts is reduced.

Description

Technical Field

[0001] This application relates to a novel bypass switch for use in a 10kV high-voltage frequency converter system. It enables local control of the bypass switches of each module at the secondary end, saving control components within each power unit module. Background Technology

[0002] Currently, bypass switches used in 10kV high-voltage frequency converters, SVG, and flexible DC converter valve power units are mainly divided into two categories: vacuum bypass switches and air bypass switches. Both have obvious shortcomings in fault bypass protection scenarios: 1. Vacuum bypass switches rely on permanent magnet mechanisms combined with vacuum interrupters, resulting in high overall costs; 2. Traditional air bypass switches use multi-stage lever locking structures and long series conductive circuits, resulting in numerous defects in the mechanism and conductive structure. Furthermore, fault repair requires complete disassembly of the equipment casing, making the maintenance process cumbersome.

[0003] 1. Disadvantages of traditional air bypass switch mechanism: It adopts a three-stage linkage unlocking structure of reset lever, trip lever and insulating pull rod. Closing requires three-stage unlocking, resulting in large transmission loss, long closing time and a large number of overall parts; 2. Disadvantages of traditional air bypass switch conductive circuit: The main circuit is a single-break structure consisting of moving side conductor, contact finger seat, spring contact finger, moving contact, and stationary side conductor connected in series. There are many conductive parts, resulting in high processing and assembly costs. 3. Defects of traditional air bypass switches in terms of withstand voltage and maintenance: They rely on closing springs to maintain the closed position, and cannot extend the insulating pull rod to increase the withstand voltage to ground, making it difficult to meet the 28kV withstand voltage requirement of a 10kV system; when the equipment malfunctions, the entire switch cover must be disassembled to inspect the internal modules, making maintenance difficult. Summary of the Invention

[0004] To solve the above-mentioned technical problems, this application provides the following technical solution: A novel bypass switch includes: a housing and a latching mechanism assembly and a conductive circuit assembly installed inside the housing; The conductive circuit assembly includes two stationary contacts and one moving contact; The locking mechanism assembly includes a pull rod, an electromagnet, and a closing spring. The upper end of the pull rod is connected to the moving contact, and the lower end of the pull rod is fitted with a closing spring. The pull rod is provided with a limiting part that is adapted to the moving push rod of the electromagnet.

[0005] Preferably, the conductive circuit assembly is installed inside one end of the housing, and the terminals of the two stationary contacts extend outside the housing.

[0006] Preferably, the pull rod is provided with a tripping operation lever.

[0007] Preferably, the tripping operation lever is located near the limiting part.

[0008] Preferably, the pull rod is arranged vertically inside the housing, the electromagnet is arranged horizontally inside the housing, and the moving push rod of the electromagnet is vertically engaged with the limiting part.

[0009] Preferably, a guide is provided in the contact area between the housing and the pull rod.

[0010] Preferably, the guide includes a first guide and a second guide, and the insulating pull rod is disposed in the area between the first guide and the second guide.

[0011] Preferably, the upper end of the insulating pull rod is provided with a frame, and the moving contact is floatingly installed in the frame.

[0012] Preferably, a contact spring is provided below the moving contact.

[0013] Preferably, the novel bypass switch includes: an auxiliary switch adapted to the limiting part. The auxiliary switch is used for status feedback of the main contact position of the switch, and the auxiliary switch push rod extends to the pull rod limiting part to adapt and complete the switching of the auxiliary switch.

[0014] Preferably, the limiting portion is in the form of a concave ring.

[0015] Preferably, the insulating rod is provided with a plurality of bosses.

[0016] Compared with the prior art, the beneficial effects achieved by this application are: 1. This application adopts a brand-new locking mechanism, which only requires one locking stage to complete the opening and closing locking and unlocking actions, eliminating the multiple sets of transmission levers in the traditional three-stage unlocking structure. The number of parts is greatly reduced, reducing processing and assembly costs. At the same time, the transmission loss is smaller and the unlocking and closing response speed is faster. 2. The conductive main circuit is simplified into a symmetrical arrangement of stationary contact-moving contact-stationary contact, abandoning the complex series structure of traditional multi-segment conductors and multi-layer contact fingers. The overall circuit has fewer parts, the assembly process is simple, and the overall production cost of the product is effectively reduced. 3. The overall ground insulation withstand voltage of this application can reach 28kV, which greatly improves the insulation performance. The ground withstand voltage index fully meets the usage standards of 10kV power distribution system, and the equipment operation safety and stability are stronger.

[0017] The core of this application lies in migrating the bypass switch control function from within each power unit and consolidating it to the secondary ground potential side, thereby achieving localized control of the bypass switches in each module. In cascaded high-voltage frequency converter systems, each power unit is at a floating high potential. Traditional solutions require independent control components within each unit to drive the bypass switch. To address this drawback, this application fully utilizes the product's excellent ground insulation performance, unifying the generation and transmission of control commands on the ground potential side. This allows for direct, safe, and stable control of the bypass switches within each module from the secondary side. This localized control scheme not only simplifies the internal structure of the power unit physically and eliminates dispersed control components, but also improves the centralization and reliability of bypass control at the system level, effectively reducing unit failure rates and maintenance costs. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the present application and form part of the specification. They are used together with the embodiments of the present application to explain the application and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the tripping position in this application; Figure 2 This is a schematic diagram of the closing position in this application; Figure 3 This is a schematic diagram of the insulating pull rod and moving contact assembly of this application; Figure 4 This is a schematic diagram of the bypass switch in this application. Figure 1 ; Figure 5 This is a schematic diagram of the air bypass switch of this application. Figure 2 This diagram and Figure 4 Different perspectives.

[0019] In the diagram: 1. Opening operating lever; 2. Pull rod; 21. Insulating pull rod; 3. Electromagnet; 4. Closing spring; 5. Auxiliary switch; 6. Stationary contact; 7. Moving contact; 8. Contact spring; 9. Housing; 91. Guide component; 92. Signal terminal. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the position or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] Example This application implements an integrated assembly design that incorporates a single-stage locking mechanism for opening and closing, a symmetrical and simplified conductive circuit, and an extended insulating tie rod. The specific design is as follows: like Figure 1 As shown, the locking mechanism assembly consists of an electromagnet 3, a pull rod 2, a closing spring 4, and a closing operating rod 1. At the closing position, the iron core of the electromagnet 3 is vertically engaged with the limiting part, which can be a concave feature of the pull rod to achieve a first-level locking limit. The closing spring 4 is installed at the bottom of the pull rod 2, and the closing operating rod 1 passes through the middle of the pull rod 2 for manual opening and closing. The entire locking mechanism is fixed inside the switch housing by a bracket; the electromagnet 3's push rod directly engages with the pull rod 2, eliminating the need for a multi-stage lever transmission structure.

[0024] like Figure 2 As shown, the conductive circuit adopts a symmetrical arrangement of stationary contact 6-moving contact 7-stationary contact 6. The moving contact 7 is floatingly installed in the end frame of the insulating rod 21. An independent contact spring 8 is installed below the moving contact 7. The contact surface of the contact is provided with a stamped convex structure. After all conductive parts are integrated and assembled, the whole is linked with the insulating rod 21.

[0025] like Figure 3 As shown, the insulating tie rod 21 is located between the conductive main circuit and the secondary control mechanism. The insulating tie rod 21 adopts an I-shaped cross section, and the rod body is provided with a boss to extend the insulation distance to the ground. Limiting ribs are provided inside the housing to constrain the movement trajectory of the tie rod. All screws and nuts assembled in the housing are made of non-metallic insulating material.

[0026] There are three bosses. All three bosses can increase electrical clearance and creepage distance, thus strengthening insulation. Figures 1-3 As shown, the bottom boss is a flat boss, which is used to limit the movement of the casing when the circuit is closed.

[0027] The central boss is larger than the two side bosses to increase the electrical clearance between the charged conductor and the ground potential of the mechanism below. The diameter of the two side bosses is smaller because they meet the creepage distance requirements and do not need to be the same as the central boss, thus reducing the overall moving mass.

[0028] In the open state, the above structure relies on electromagnet 3 to maintain the position. When the switch is closed, the electromagnet unlocks, and the closing spring 4 directly drives the insulating pull rod to complete the closing. There are fewer transmission links and the closing speed is fast. The independent contact spring 8 continuously ensures the contact pressure of the contact, and the conductive circuit heats up less. At the same time, the extended insulating pull rod 10 is equipped with non-metallic fasteners, and the whole machine can withstand a ground voltage of up to 28kV, which meets the 10kV system use standard.

[0029] like Figure 4 / 5, The signal terminals that connect to the electromagnet and auxiliary switch extend out of the housing. The signal terminals include two ± wires for controlling the electromagnet's action and two wires for the auxiliary switch's position feedback.

[0030] This application features a smaller overall structure with lower processing and assembly costs. Equipped with a manual operating lever, it allows for manual operation of opening and closing the circuit breaker during power outage maintenance. The split-type housing design allows for individual disassembly and maintenance of the locking mechanism, conductive circuit, and insulating pull rod 21, eliminating the need for complete switch disassembly during fault maintenance and reducing maintenance difficulty.

[0031] The working principle of this application is as follows: When closing, the electromagnet is energized after receiving the command from the back office. The moving rod of the electromagnet's moving iron core is pulled back. The pull rod is pushed upward by the closing spring at the tail, which moves the insulating pull rod and the moving contact. After the moving contact contacts the stationary contact, the circuit closes. The pull rod continues to move upward and goes over the limit. The protrusion of the insulating pull rod contacts the housing and is limited. When opening, the opening operation rod is manually rotated to move the pull rod, the insulating pull rod and the moving contact. The moving contact separates from the stationary contact. The moving rod of the electromagnet is slid into the groove of the pull rod by the force of the reset spring to complete the opening limit.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Finally, it should be noted that the above are merely preferred embodiments of this application and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A novel bypass switch, characterized in that, include: The housing and the locking mechanism assembly and conductive circuit assembly installed inside the housing; The conductive circuit assembly includes two stationary contacts and one moving contact; The locking mechanism assembly includes a pull rod, an electromagnet, and a closing spring. The upper end of the pull rod is connected to the moving contact, and the lower end of the pull rod is fitted with a closing spring. The pull rod is provided with a limiting part that is adapted to the moving push rod of the electromagnet.

2. The novel bypass switch as described in claim 1, characterized in that, The conductive circuit assembly is installed inside one end of the housing, and the terminals of the two stationary contacts extend outside the housing.

3. A novel bypass switch as described in claim 1, characterized in that, The lever is equipped with a tripping control lever.

4. A novel bypass switch as described in claim 3, characterized in that, The tripping control lever is located near the limiting part.

5. A novel bypass switch as described in claim 1, characterized in that, The pull rod is vertically arranged inside the housing, the electromagnet is horizontally arranged inside the housing, and the moving push rod of the electromagnet is vertically engaged with the limiting part.

6. A novel bypass switch as described in claim 1, characterized in that, The contact area between the housing and the pull rod is provided with a guide.

7. A novel bypass switch as described in claim 1, characterized in that, The guide includes a first guide and a second guide, and the insulating pull rod is disposed in the area between the first guide and the second guide.

8. A novel bypass switch as described in claim 1, characterized in that, The upper end of the insulating pull rod is provided with a frame, and the moving contact is floatingly installed in the frame.

9. A novel bypass switch as described in claim 1, characterized in that, include: An auxiliary switch is adapted to the limiting part.

10. A novel bypass switch as described in claim 1, characterized in that, The limiting part is in the shape of a concave ring.

11. A novel bypass switch as described in claim 1, characterized in that, The insulating tie rod is provided with several protrusions.

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