Internal and external double-shielding type short-size contact box
By designing a short-sized contact box with internal and external double shielding, the corona discharge problem caused by using the contact box in conjunction with the bent partition is solved, and the contact box can meet the insulation requirements independently, thus avoiding the occurrence of insulation failure.
Patent Information
- Application Number
- CN202520275600.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-20
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2035-02-20
AI Technical Summary
Existing contact boxes in switchgear need to be used in conjunction with bent partitions to meet insulation requirements. This results in the phase-to-phase voltage or phase-to-ground voltage being shared by the epoxy resin insulation material and the air gap, which can easily cause corona discharge and may lead to insulation failure after long-term operation.
The short-sized contact box with internal and external double shielding is adopted, including an insulation structure, a conductor structure, a high-voltage shielding structure and a low-voltage shielding structure. The high-voltage shielding structure is electrically connected to the conductor structure, and the low-voltage shielding structure is connected to the external ground. The insulation structure bears all phase-to-phase voltage and phase-to-ground voltage, avoiding the concentration of electric field in the air gap.
It effectively avoids corona discharge, improves insulation performance, avoids insulation failure caused by high electric field strength in air gaps, and enables the contact box to meet insulation requirements when used alone.
Smart Images
Figure CN223757847U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a contact box for switch cabinet technical field, especially in and out double shielding type short size contact box. BACKGROUND
[0002] At present, the contact box for switch cabinet on the market generally has the following problems: the contact box cannot complete its function alone, and must be used together with the matching bend spacer in the switch cabinet to meet the insulation requirements. In actual application, the two adjacent contact boxes and the contact box and the bend spacer must be used in splicing, resulting in a splicing gap, which makes the inter-phase voltage or the relative ground voltage borne by the epoxy resin insulation material and the air gap. Due to the different voltages induced on the surfaces of the two insulation pieces, and due to the distribution of the stray capacitance in the epoxy resin insulation material and the small air gap, the small air gap bears a large part of the induced voltage. Since the air gap is very small, the electric field strength is very high, which can cause corona discharge in the air gap. When the product is in operation, the surface of the two adjacent contact boxes and the contact box and the bend spacer will generate induced charges and induced voltages. This induced voltage can cause corona discharge in the small air gap between the adjacent contact boxes and the contact box and the bend spacer. Long-term operation can cause insulation failure, resulting in damage to the equipment.
[0003] It should be noted that the information disclosed in this BACKGROUND section is only intended to increase the understanding of the overall background of the present utility model, and should not be considered as acknowledging or implying in any form that this information constitutes prior art known to those skilled in the art. CONTENT OF THE UTILITY MODEL
[0004] The utility model provides a kind of inside and outside double shielding type short size contact box, it includes insulation structure, conductor structure, high voltage shielding structure and low voltage shielding structure.The insulation structure has inner chamber.Conductor structure connects the insulation structure, and is located in the inner chamber.High voltage shielding structure is arranged in insulation structure, and is connected with the conductor structure.Low voltage shielding structure is arranged in insulation structure, the high voltage shielding structure is closer to the conductor structure compared with the low voltage shielding structure, and the low voltage shielding structure is used to connect external ground.
[0005] Further, annular grooves are provided in the insulation structure, which extend along the radial depth direction, and the low voltage shielding structure is closer to the conductor structure compared with the annular grooves.
[0006] Further, the number of annular grooves is 2, which are distributed on different sides of the insulation structure.
[0007] Further, the incoming line end and the outgoing line end of the conductor structure are not on the same horizontal plane.
[0008] Further, the high-voltage shielding structure is elliptical.
[0009] Further, the low-voltage shielding structure is elliptical.
[0010] Further, the material of the insulation structure comprises epoxy resin.
[0011] Further, the outer edge of the insulation structure is a square structure.
[0012] Further, the low-voltage shielding structure is connected with a steel plate of an external grounding potential.
[0013] Further, the inner-outer double shielding type short-size contact box is used for a 40.5kV switch cabinet.
[0014] The inner-outer double shielding type short-size contact box provided by the utility model, through the collocating setting of the insulation structure, the conductor structure, the high-voltage shielding structure and the low-voltage shielding structure, since the high-voltage shielding structure is electrically connected with the conductor structure, the potential between the two is equal, the low-voltage shielding structure is connected with the external grounding, the potential between the two is equal, and then the phase-to-phase voltage and the phase-to-ground voltage in the original structure, which are borne by the insulation structure and the air gap, are all introduced into the insulation structure.
[0015] Other features and advantages of the utility model will be described in the subsequent specification, and part of the technical features and advantages can be obviously obtained from the specification, or be understood by implementing the utility model. BRIEF DESCRIPTION OF DRAWINGS
[0016] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and obviously, part of the drawings in the following description is some embodiments of the utility model, and for those skilled in the art, under the premise of not paying creative labor, other drawings can also be obtained according to these drawings.
[0017] Figure 1 It is the three-dimensional schematic view of the inner-outer double shielding type short-size contact box provided by an embodiment of the utility model;
[0018] Figure 2 It is the structural schematic view of the inner-outer double shielding type short-size contact box provided by an embodiment of the utility model.
[0019] Reference signs:
[0020] 1 - conductor structure; 2 - high voltage shielding structure; 3 - low voltage shielding structure; 4 - annular groove; 5 - insulation structure. DETAILED DESCRIPTION
[0021] To make the objects, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application; as long as there is no conflict, the technical features in the different embodiments of the present application described below can be combined with each other; based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the scope of protection of the present application.
[0022] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "transverse", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or component referred to must have a particular orientation, or be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more. In addition, the term "comprising" and any variations thereof mean "at least including".
[0023] Please refer to Figure 1 and Figure 2 , Figure 1 is a perspective view of an inner-outer double shielding type short size contact box provided by an embodiment of the present application; Figure 2 is a structural view of an inner-outer double shielding type short size contact box provided by an embodiment of the present application. To achieve at least one of the above advantages or other advantages, an embodiment of the present application provides an inner-outer double shielding type short size contact box. As shown in the figure, the inner-outer double shielding type short size contact box includes an insulation structure 5, a conductor structure 1, a high voltage shielding structure 2, and a low voltage shielding structure 3.
[0024] The insulation structure 5 has an inner chamber. The insulation structure 5 is prepared from an insulating material, for example, an epoxy insulating material.
[0025] The conductor structure 1 is connected to the insulation structure 5 and is located in the inner chamber. The conductor structure 1 can be made of a metal material and can be a high-voltage conductor. Alternatively, the conductor structure 1 of the main circuit is cast inside the insulation structure 5, and the insulation structure 5 supports the conductor structure 1.
[0026] The high-voltage shielding structure 2 is arranged in the insulation structure 5 and is connected to the conductor structure 1.
[0027] The low-voltage shielding structure 3 is arranged in the insulation structure 5, and the high-voltage shielding structure 2 is closer to the conductor structure 1 than the low-voltage shielding structure 3, that is, the high-voltage shielding structure 2 is an inner shielding structure, and the low-voltage shielding structure 3 is an outer shielding structure. The low-voltage shielding structure 3 is used to connect to an external ground. Alternatively, the low-voltage shielding structure 3 is connected to a steel plate with an external ground potential.
[0028] Because the high-voltage shielding structure 2 is electrically connected to the conductor structure 1, the potential between the two is equal; the low-voltage shielding structure 3 is connected to the external ground, and the potential between the two is equal, thereby making the inter-phase voltage and the voltage to ground in the original structure, which is borne by the insulation structure 5 and the air gap together, all introduced into the insulation structure 5. In this way, the inter-phase voltage and the voltage to ground are all borne by the insulation structure 5 with good insulation performance, that is, by using the high-low voltage inner-outer double shielding structure, the electric field concentration part is introduced into the insulation structure 5 with high insulation strength, thereby avoiding the possibility of corona discharge in the air gap between adjacent contact boxes and between the contact box and the bending spacer under long-term operation, and the possibility of insulation failure. Moreover, the problem caused by using the bending spacer is avoided, and the problem that the side-phase contact box cannot complete its function alone and must be used together with the matching bending spacer to meet the insulation requirements is solved.
[0029] In the present embodiment, the annular groove 4 is arranged in the insulation structure 5 and extends along the radial depth direction, and the low-voltage shielding structure 3 is closer to the conductor structure 1 than the annular groove 4. The annular groove 4 can play the role of an umbrella skirt, increase the creepage distance, meet the standard requirements, and will not affect the shielding effect because it is arranged outside the high-voltage shielding structure 2 and the low-voltage shielding structure 3. Further, the number of annular grooves 4 is two, which are distributed on different sides of the insulation structure 5, so that the contact insertion depth is relatively small, which is beneficial to heat dissipation of the contact.
[0030] Considering that each phase contact box is used in pairs, namely, the upper contact box matched with the upper contact arm on the circuit breaker and the lower contact box matched with the lower contact arm on the circuit breaker, according to the structure and compartment requirements of the switch cabinet, it is required that the upper and lower contact boxes are separated by a steel plate, and the traditional contact box is arranged at a relatively far position due to the insulation requirement, which requires the size of the contact box to be increased. In order to solve the problem, the conductor structure 1 is controlled to be not in the same horizontal plane at the incoming line end and the outgoing line end, and the outgoing line end is formed with a certain height distance from the incoming line end, so as to solve the above problem.
[0031] Further, in order to completely shield the conductor structure 1, the high-voltage shielding structure 2 is in an elliptical shape, and the low-voltage shielding structure 3 is in an elliptical shape. Correspondingly, the middle core part of the contact box is also designed as an elliptical structure. Further, in order to facilitate the installation and splicing of the contact box, the outer edge of the insulation structure 5 is in a square structure.
[0032] In some embodiments, the inner-outer double shielding type short size contact box can be used in a 40.5kV switch cabinet.
[0033] In summary, the inner-outer double shielding type short size contact box provided by the utility model has the advantages that the insulation structure 5, the conductor structure 1, the high-voltage shielding structure 2 and the low-voltage shielding structure 3 are collocated and arranged, the high-voltage shielding structure 2 is electrically connected with the conductor structure 1, the potential between the two is equal, the low-voltage shielding structure 3 is connected with the external ground, the potential between the two is equal, and the phase-to-phase voltage and the phase-to-ground voltage originally borne by the insulation structure 5 and the air gap in the original structure are all introduced into the insulation structure 5. In this way, the phase-to-phase voltage and the phase-to-ground voltage are all borne by the insulation structure 5 with good insulation performance, so that the possibility of insulation failure under long-time operation can be avoided. Moreover, the problems caused by the use of the bent partition plate are avoided, and the problem that the side phase contact box cannot complete its function alone and must be used together with the matching bent partition plate to meet the insulation requirements is solved.
[0034] In addition, those skilled in the art should understand that although there are many problems in the prior art, each embodiment or technical solution of the utility model can only be improved in one or several aspects, and it is not necessary to solve all the technical problems listed in the prior art or background art at the same time. Those skilled in the art should understand that the content not mentioned in a claim should not be regarded as a limitation of the claim.
[0035] Finally, it should be noted that: the above embodiments are used to illustrate the technical solutions of the present application, but not limited to them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. A short-sized contact box with internal and external double shielding, characterized in that: The internally and externally double-shielded short-size contact box includes: An insulating structure having an internal cavity; A conductor structure, connecting the insulating structure, and located within the inner cavity; A high-voltage shielding structure is installed inside the insulating structure and connected to the conductor structure; A low-voltage shielding structure is disposed within an insulating structure. The high-voltage shielding structure is closer to the conductor structure than the low-voltage shielding structure. The low-voltage shielding structure is used to connect to an external ground.
2. The short-size contact box with internal and external double shielding according to claim 1, characterized in that: The insulating structure has an annular groove extending in the radial depth direction, and the low-voltage shielding structure is closer to the conductor structure than the annular groove.
3. The short-size contact box with internal and external double shielding according to claim 2, characterized in that: There are two annular grooves, distributed on different sides of the insulation structure.
4. The short-size contact box with internal and external double shielding according to claim 1, characterized in that: The input and output terminals of the conductor structure are not on the same horizontal plane.
5. The short-size contact box with internal and external double shielding according to claim 1, characterized in that: The high-voltage shielding structure is elliptical in shape.
6. The short-size contact box with internal and external double shielding according to claim 1, characterized in that: The low-voltage shielding structure is elliptical in shape.
7. The short-size contact box with internal and external double shielding according to claim 1, characterized in that: The insulating structure is made of epoxy resin.
8. The short-size contact box with internal and external double shielding according to claim 1, characterized in that: The outer edge of the insulation structure is square.
9. The short-size contact box with internal and external double shielding according to claim 1, characterized in that: The low-voltage shielding structure is connected to a steel plate with an external grounding potential.
10. The short-size contact box with internal and external double shielding according to claim 1, characterized in that: The internally and externally shielded short-size contact box is used in 40.5kV switchgear.