Distributed parallel contact structure and applied vacuum arc-extinguishing chamber
Patent Information
- Application Number
- CN202510574048.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-06
- Publication Date
- 2025-07-04
Smart Images
Figure CN120261216A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of power switches, and particularly to a distributed parallel contact structure and a vacuum interrupter using the same. Background Art
[0002] The main problems in switching loads by high-voltage circuit breakers are closing inrush current and breaking overvoltage, that is, closing inrush current that may burn out equipment or lines during closing, and breaking overvoltage that may break down the insulation of equipment or lines during opening. A vacuum interrupter is a key component in high-voltage vacuum switchgear.
[0003] Existing vacuum interrupters usually adopt a single contact structure. When closing the circuit, a high-frequency closing inrush current dozens of times or even dozens of times the rated current may be generated, directly burning out the loop equipment or lines, or damaging the surface morphology of the contacts of the vacuum interrupter due to burning, and then it is difficult to withstand the breaking overvoltage when the high-voltage vacuum circuit breaker breaks the circuit, affecting its breaking performance. Closing inrush current burning is one of the factors for the decline of the closing ability and life of vacuum circuit breakers. Therefore, a new type of contact structure is needed to improve the closing ability of the vacuum interrupter and the reliability of the equipment, in order to reduce the maximum inrush current borne by the contacts of the high-voltage vacuum interrupter and alleviate or even eliminate the impact of the damage to the surface morphology of the contacts caused by high-frequency inrush current burning on the breaking performance of the high-voltage vacuum circuit breaker. Summary of the Invention
[0004] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a distributed parallel contact structure and a vacuum interrupter using the same. Considering that the vacuum arc characteristic is a positive volt-ampere characteristic, different from the negative volt-ampere characteristic of gas arcs, the present invention adopts a shunt strategy to reduce the closing inrush current of the vacuum interrupter, convert the single-point high-intensity burning of the contact inrush current into multi-point low-intensity burning, and convert the uncontrollable high-intensity arcing problem in the vacuum medium into a controllable arcing channel mediated by distributed contacts and low-intensity arcing. The peak value of the inrush current borne by each contact during closing of the high inrush current parameter circuit breaker is greatly reduced, thereby solving the problems of the burning hazard of the inrush current during closing of the high-voltage vacuum circuit breaker and the decline of the breaking performance of the contacts caused by closing burning in the prior art.
[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:
[0006] A distributed parallel contact structure includes a distributed parallel contact 100 and a switch control module 200 for controlling the operation of the distributed parallel contact 100; the distributed parallel contact 100 includes N groups of contact units 101 connected in parallel, where N≥2; each group of contact units 101 includes a pair of conductive contact fingers 102, and there is a vacuum 103 between the N groups of contact units 101 connected in parallel both horizontally and vertically, forming N parallel closing branches.
[0007] Each of the contact units 101 may be an embedded structure 104 in which the contact fingers on one side of the contact protrude and the contact fingers on the other side are recessed. When closed, the concave and convex surfaces at both ends come into contact to form N parallel closing branches; or it may be a butt joint structure 105 in which the contact fingers on both sides of the contact protrude. When closed, the convex surfaces at both ends come into contact to form N parallel closing branches; or it may be a cross structure 106 in which the contact fingers on both sides protrude alternately. When closed, the convex surfaces protruding alternately at both ends come into contact with the plane on the opposite side to form N parallel closing branches. These contact unit structures can all provide parallel metal conduction paths for the closing inrush current, guide the total closing inrush current to be shunted, and disperse the single-point concentrated arcing energy to multiple groups of parallel contact units, thereby reducing the risk of contact ablation.
[0008] The contact surfaces of a pair of conductive contact fingers 102 of each of the contact units 101 are circular 107 or polygonal 108. The polygon 108 is an equilateral polygon. The contact finger surfaces of these shapes can also provide parallel metal conduction paths for the closing inrush current and guide the closing inrush current to be shunted.
[0009] The cross-sectional area of each conductive contact finger 102 of each of the contact units 101 is smaller than the cross-sectional area of a single contact and is 1 / N of the cross-sectional area of a single contact, which improves the uniformity of the materials of each parallel contact and can effectively solve the problems of the burning damage caused by the inrush current during the closing of a high-voltage circuit breaker and the degradation of the opening performance of the contact after closing and burning.
[0010] The switch control module 200 controls the number of switch contact groups and the synchronism of the distributed parallel contacts 100.
[0011] A vacuum interrupter, and the vacuum interrupter includes the above-mentioned distributed parallel contact structure.
[0012] Compared with the prior art, the present invention has the following advantages:
[0013] The distributed parallel contact structure and the applied vacuum interrupter provided by the present invention, based on the idea of "diverting rather than blocking", when the contacts close the high-frequency inrush current arc, a large number of parallel branches are used to shunt the closing inrush current of the main circuit, forming a distributed multi-parallel synchronous closing circuit, which fundamentally greatly reduces the peak value of the closing inrush current of each synchronous closing contact. The traditional single-point concentrated arcing energy in the vacuum interrupter is dispersed to multiple groups of parallel contact units, reducing the risk of contact ablation, and can improve the closing ability and service life of the vacuum interrupter.
[0014] Under the prior art, the contacts with high inrush current parameters in a closing circuit always face the problems of closing and burning damage and the degradation of the opening performance of the contacts after closing and burning; in addition, it is difficult to ensure the consistency of the impedances of the parallel branches in a double circuit breaker parallel closing circuit, and the circuit with a lower impedance is more likely to be burned and damaged; as the voltage level increases, while the volume of the contacts of a high-voltage vacuum circuit breaker increases, it is difficult to ensure the uniformity of the materials, which will also increase the destructive force of the inrush current burning.
[0015] The present invention can not only effectively reduce the maximum inrush current peak value of each contact unit through shunt, but also ensure the consistency of the impedance of parallel branches as much as possible by sharing a single closing circuit. Moreover, it can improve the uniformity of the materials of each parallel contact finger by reducing the cross-section of the contact, so as to mitigate or even eliminate the damage to the contact caused by the closing inrush current burning, and solve the problem that the opening performance of the high-voltage vacuum circuit breaker decreases due to the damage to the surface morphology of the contact caused by burning. Brief Description of the Drawings
[0016] Figure 1 is a schematic diagram of the distributed parallel shunt closing circuit of the present invention, and the initial state of each parallel branch is open ( Figure 1 (in (a)), and each parallel branch closes synchronously during closing ( Figure 1 (in (b)).
[0017] Figure 2 is a schematic circuit diagram of the distributed parallel contact structure of the present invention.
[0018] Figure 3 is a schematic side view of an embodiment of the distributed parallel contact structure of the high-voltage vacuum interrupter of the present invention.
[0019] Figure 4 is a schematic longitudinal sectional view of an embodiment of the contact unit in the distributed parallel contact structure of the present invention. Among them, (a) is an embedded structure with one side of the contact unit protruding and the other side recessed, (b) is a butt joint structure with both sides of the contact unit protruding, and (c) is a cross structure with both sides of the contact unit protruding alternately.
[0020] Figure 5 is a schematic cross-sectional view of an embodiment of the contact finger in the distributed parallel contact unit of the present invention. Among them, (a) the surface of the contact finger is circular, and (b) the surface of the contact finger is polygonal.
[0021] Figure 6 is a curve graph showing the relationship between the number of distributed parallel contacts in a 35 kV system and the maximum closing inrush current peak value flowing through each contact. Detailed Embodiments
[0022] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0023] As Figure 1 shown is a schematic diagram of the distributed parallel shunt closing circuit of the high-voltage vacuum circuit breaker of the present invention. Based on the idea of "diverting rather than blocking", the initial state of each parallel branch is open (Figure 1 In (a) below, when the contact closes the high-frequency inrush current arc, each parallel branch closes synchronously during closing. Figure 1 In (b) below. A large number of parallel branches are used to shunt the closing inrush current of the main circuit, forming a distributed multi-parallel synchronous closing circuit, which effectively reduces the peak value of the closing inrush current of each closing circuit fundamentally. The traditional single-point concentrated arcing energy in the vacuum interrupter is dispersed into multiple groups of parallel closing channels, reducing the peak value of the high-frequency inrush current of the closing circuit, reducing the risk of contact ablation, and thus improving the closing ability and service life of the vacuum interrupter.
[0024] As Figure 2 shown is a circuit schematic diagram of the distributed parallel contact structure. The distributed closing contact of the high-voltage circuit breaker provided by the present invention includes a distributed parallel contact 100 and a switch control module 200 for controlling the synchronous closing of multiple parallel contacts in the distributed parallel contact 100. The distributed parallel contact 100 is connected in series in the high-inrush current closing circuit.
[0025] The switch control module 200 controls the number of closed contacts and the synchronization of the distributed parallel contact 100. It can synchronously close all contact units 101, or select the number of parallel contact units to be closed according to the peak value of the inrush current that may appear in the closing circuit, and then control these multiple parallel contact units to close synchronously. It can also close some contact units synchronously, or alternately close groups of contact units synchronously in turn.
[0026] In the embodiment of the present invention, a large number of parallel contact units 101 are distributed in the distributed parallel contact 100, so that the total closing circuit current is shunted, greatly reducing the peak value of the closing inrush current of each contact unit 101. Thus, the maximum inrush current borne by the contacts of the high-voltage circuit breaker can be effectively reduced, and the influence of the damage to the surface morphology of the contacts due to burning on the opening performance of the high-voltage circuit breaker can be alleviated or even eliminated.
[0027] As Figure 3The figure shows a side view schematic diagram of the structure of the distributed parallel contacts 100 of the high-voltage vacuum interrupter of the present invention. The distributed parallel contacts 100 include N groups of contact units 101 connected in parallel, where N≥2; a vacuum 103 is filled between the multiple contact units 101 connected in parallel both horizontally and vertically. It is applicable to the closing scenario with high inrush current parameters. When the high-voltage contacts are closed, multiple parallel contact units are used to shunt the closing inrush current of the main contacts, which can greatly reduce the peak value of the inrush current borne by each contact unit when the high-inrush current parameter circuit breaker is closed. In principle, each synchronously closed contact does not bear an excessive closing inrush current, thus effectively solving the problem of the burning hazard of the inrush current when the high-voltage vacuum circuit breaker is closed and the degradation of the breaking performance of the contacts after closing and burning. All parallel contact units can be synchronously closed, or the number of groups of parallel contact units to be closed can be selected according to the peak value of the inrush current that may appear in the closing circuit, and then these parallel contact units are controlled to be synchronously closed, or the grouped contact units can be alternately synchronously closed in turn.
[0028] In the embodiment of the distributed parallel contacts 100, not only can the maximum inrush current peak value of each contact be effectively reduced due to shunting, but also the consistency of the impedance of the parallel branches can be ensured because a common closing circuit is shared. Moreover, the uniformity of the materials of each parallel contact can be improved due to the reduction of the contact cross-section. Therefore, the damage to the contacts caused by the closing inrush current burning and the problem of the degradation of the breaking performance of the high-voltage circuit breaker due to the damage to the surface morphology of the contacts caused by burning can be alleviated or even eliminated.
[0029] It should be noted that the closing main circuit and each parallel branch can be integrally formed first, and then the break is laser cut to ensure that each pair of conductive contact fingers can be accurately closed. The distributed parallel contact structure of the present invention adopts one closing circuit, one circuit breaker, and multiple contacts, which is beneficial to the consistency of the impedance of each parallel branch and to parallel current sharing. Also, each parallel contact unit 101 and the closing main circuit can be made into discrete components, which is beneficial to the replacement of individual contact components. In addition, the contact material of the branch can be different from the conductor material of the main circuit, and a suitable material can be selected according to the main problems it faces.
[0030] As Figure 4 shown is the structure of each group of parallel contact units 101 in the distributed parallel contact structure, which can be an embedded structure 104 with the contact fingers protruding on one side and recessed on the other side, as Figure 4 shown in (a); or it can be a butt joint structure 105 with the contact fingers protruding on both sides of the contact, as Figure 4 shown in (b); or it can also be a cross structure 106 with the contact fingers protruding alternately on both sides of the contact, as Figure 4 shown in (c).
[0031] As Figure 5The cross-sectional schematic diagram of the finger embodiment in the distributed parallel contact unit of the present invention is shown. In the structure of the distributed parallel contact 100, the contact surfaces of the conductive fingers 102 on both sides of each contact unit 101 can be circular 107, as Figure 5 shown in (a); or can be (equilateral) polygon 108, as Figure 5 shown in (b).
[0032] Vacuum interrupter applying the distributed parallel contact structure of the present invention: The distributed parallel contact structure is applied to the vacuum interrupter. The vacuum interrupter includes a housing, a contact system, an insulating support, and a vacuum seal. The contact system adopts the distributed parallel contact structure to improve the arc extinguishing effect and the reliability of the equipment.
[0033] As Figure 6 shown is the relationship curve graph between the number of distributed parallel contacts in the 35 kV system and the peak value of the maximum closing inrush current flowing through each contact. The simulation results of the embodiment show that when closing the circuit, the peak value of the maximum closing inrush current borne by each contact is related to the number of contacts. The more the number of contacts, the smaller the peak value of the maximum closing inrush current borne by each contact. The peak value of the maximum closing inrush current borne by each contact is inversely proportional to the number of contacts.
[0034] To enable those skilled in the art to better understand and implement the technical solution of the present invention, the role of setting the distributed parallel contact when closing the high-frequency inrush current arc in the vacuum circuit breaker will be introduced first below.
[0035] When a conventional high-voltage vacuum circuit breaker closes the circuit, a high-frequency inrush current arc with a frequency reaching several hundred to several thousand hertz and an amplitude up to dozens of times the normal operating current may be generated.
[0036] To better illustrate the advantages of the present invention, the method of closing the high inrush current parameter circuit in the prior art will be introduced below.
[0037] In the prior art, for closing the contacts of a high inrush current parameter loop, problems such as closing burn damage and the decline of the opening performance of the contacts after closing burn occur. If the double circuit breaker parallel closing loop is adopted, it is difficult to ensure the consistency of the impedance of the parallel branches, and it is difficult to ensure the homogeneity of the material while the volume of the high-voltage circuit breaker contacts increases. In addition, the repeated burning of the contacts may exacerbate their inhomogeneity. Therefore, the prior art cannot fundamentally reduce the harm of the closing inrush current and its influence on the opening performance of the contacts.
[0038] In view of the above problems, the distributed parallel contact structure and the applied vacuum interrupter proposed by the present invention are based on the principle of parallel shunt of the circuit, as Figure 2The closing circuit shown is provided with distributed multi-parallel contacts. When the vacuum arc extinguishing chamber including the distributed parallel contacts closes the circuit, the switch control module in the distributed parallel contact structure of the present invention controls the synchronous closing of multiple groups of parallel contact units. Each parallel contact unit shunts the total inrush current, which can effectively reduce the inrush current peak value borne by each contact unit. Compared with the prior art, when closing a high-inrush current parameter circuit, such as Figure 3 As shown in the embodiment of the distributed parallel contact structure of the high-voltage vacuum arc extinguishing chamber of the present invention, it can not only effectively reduce the maximum inrush current peak value of each finger due to shunting, but also ensure the consistency of the impedance of the parallel branches due to sharing a closing loop. It can also improve the uniformity of the materials of each parallel contact due to reducing the contact cross-section, and can effectively solve the problem of the burning hazard of the inrush current during the closing of the high-voltage circuit breaker and the degradation of the opening performance of the contact after closing and burning.
[0039] The following details the current limiting effect of the distributed parallel contacts provided by the present invention and the vacuum arc extinguishing chamber in which they are applied on the high-frequency closing inrush current in combination with specific data.
[0040] Based on the simulation model built with typical data, a calculation and analysis is carried out on the switching-on operation of a certain 35 kV high-inrush current parameter circuit breaker:
[0041] The following compares the maximum closing inrush current peak values of a single contact and multi-parallel contacts.
[0042] Figure 2 In the single contact unit K in the initial state is open. When the circuit is closed at the moment of the voltage peak value of the single contact unit K, the current peak value flowing through the single contact unit K is the largest. In the embodiment, Figure 3 In the distributed parallel contacts, the number of contacts put into operation is 2, 3,..., 10,... Each contact unit closes synchronously. The relationship curve between the number of distributed parallel contacts in the embodiment and the maximum closing inrush current peak value flowing through each contact is as shown in Figure 6 shown.
[0043] The simulation results of the embodiment show that: when closing the circuit, the maximum closing inrush current peak value borne by each contact unit K1, K2,..., Kn on each parallel branch is related to the number of contact units. The more the number of contact units, the smaller the maximum closing inrush current peak value borne by each contact unit. The maximum closing inrush current peak value borne by each contact unit is inversely proportional to the number of contact units.
[0044] From the above analysis, it can be seen that in the embodiment of the distributed contact high-voltage circuit breaker closing method proposed by the present invention, based on the principle of parallel shunting of the circuit, when setting the synchronous closing of distributed multi-parallel branches, each parallel branch shunts the total inrush current of the shunting circuit, which can greatly reduce the inrush current peak value borne by the contacts of each branch.
[0045] Compared with the prior art, when closing a high inrush current parameter circuit by adopting the solution provided by the present invention, the maximum inrush current peak value of each contact unit can be effectively reduced due to parallel shunting, and the problems of the burning hazard of the inrush current during the closing of the high-voltage circuit breaker and the decline of the contact breaking performance after the closing and burning can be effectively solved.
[0046] By adopting the method of the present invention, the closing inrush current of the high-voltage circuit breaker is shunted by distributed parallel contacts, which can effectively reduce the maximum inrush current peak value flowing through each contact and its influence on the contact breaking performance, reduce the occurrence probability of the inrush current burning hazard and the re-breakdown during the opening of the high-voltage circuit breaker, and is beneficial to ensuring the safety of the equipment and the safe and stable operation of the power grid. By adopting the distributed parallel contacts and the applied vacuum interrupter provided by the present invention, the problems of the burning hazard of the high-frequency inrush current during the closing of the high-voltage circuit breaker and the decline of the contact breaking performance after the closing and burning can be solved.
[0047] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the technical solution of the present invention still fall within the scope of the protection of the technical solution of the present invention.
Claims
1. A distributed parallel contact structure, characterized in that, It includes a distributed parallel contact (100) and a switch control module (200) for controlling the operation of the distributed parallel contact (100); the distributed parallel contact (100) includes N groups of contact units (101) connected in parallel, where N≥2; each group of contact units (101) includes a pair of conductive contact fingers (102), and there is a vacuum (103) between the N groups of contact units (101) connected in parallel both horizontally and vertically, forming N parallel closing branches.
2. The distributed parallel contact structure according to claim 1, characterized in that Each group of the contact units (101) is an embedded structure (104) with one side of the contact finger protruding and the other side recessed, or a butt joint structure (105) with both sides of the contact finger protruding, or a cross structure (106) with the contact fingers protruding alternately on both sides of the contact.
3. The distributed parallel contact structure according to claim 1, characterized in that The contact surfaces of the pair of conductive contact fingers (102) of each group of the contact units (101) are circular (107) or polygonal (108).
4. The distributed parallel contact structure according to claim 1, characterized in that, The polygon (108) is an equilateral polygon.
5. The distributed parallel contact structure according to claim 1, characterized in that, Under the same voltage level, the cross-sectional area of each conductive contact finger (102) of each group of the contact units (101) is smaller than the cross-sectional area of a single contact, and is 1 / N of the cross-sectional area of a single contact, where N is the number of groups of parallel contacts.
6. The distributed parallel contact structure according to claim 1, characterized in that, The switch control module (200) controls the number of switch contact groups and the synchronization of the distributed parallel contact (100).
7. A vacuum interrupter, characterized in that, The vacuum interrupter includes the distributed parallel contact structure according to any one of claims 1 to 5.