A high-protection low-voltage draw-out switch cabinet and a protection method thereof

Abstract

The application discloses a high-protection low-voltage draw-out type switch cabinet and a protection method thereof, and relates to the technical field of electrical equipment. The switch cabinet comprises a cold-rolled steel plate outer shielding layer, the inner side of the cold-rolled steel plate outer shielding layer is connected with a double-layer shielding assembly, the inner side of the double-layer shielding assembly is provided with symmetrically-arranged connecting grooves, the connecting grooves are internally provided with draw-out type element mounting assemblies, the draw-out type element mounting assemblies comprise connecting bottom plates mounted in the connecting grooves, the top of each connecting bottom plate is provided with a metal shielding cover, the side wall and the bottom wall of the metal shielding cover are respectively provided with symmetrically-arranged sliding grooves one and two, the inner side of the sliding groove one is internally provided with sliding plates, the two groups of sliding plates are provided with a fixed plate therebetween, and the bottom of the fixed plate is provided with a ball guide rail. The double-layer shielding assembly arranged on the inner side of the cold-rolled steel plate outer shielding layer can solve the problems that the existing switch cabinet has poor adaptability in a complex electromagnetic environment and is prone to element failure and signal distortion caused by electromagnetic interference.

Description

Technical Field

[0001] This invention relates to the field of electrical equipment technology, specifically to a highly protective low-voltage withdrawable switchgear and its protection method. Background Technology

[0002] Traditional low-voltage withdrawable switchgear cannot construct a wide-band, multi-layered electromagnetic shielding system with strong anti-pulse capabilities. It cannot effectively cope with low- and medium-frequency electromagnetic interference and electromagnetic pulse impact in complex electromagnetic environments, resulting in frequent failures of internal electrical components and severe signal distortion in strong electromagnetic interference scenarios. The low-voltage withdrawable switchgear of this application can solve the problems of poor adaptability of existing switchgear in complex electromagnetic environments and easy component failure and signal distortion caused by electromagnetic interference.

[0003] The existing low-voltage withdrawable switchgear has the following drawbacks:

[0004] 1. Patent document CN108429178B discloses a low-voltage withdrawable switchgear. This document mainly considers how to solve the problem that when the drawer unit is withdrawn, it is not possible to effectively prevent the drawer unit from falling accidentally, which is not conducive to the operation of the equipment by the operator. However, it does not consider how to solve the problem that the existing switchgear has poor adaptability to complex electromagnetic environment and is prone to component failure and signal distortion due to electromagnetic interference.

[0005] 2. Patent document CN106786036B discloses a low-voltage withdrawable switchgear. This document mainly considers how to solve the problem of heat generation in the switchgear, but does not consider how to solve the problems of poor electromagnetic compatibility and low maintenance efficiency caused by unreasonable component layout and installation structure in existing switchgear.

[0006] 3. Patent document CN118739102B discloses a low-voltage withdrawable switchgear. This document mainly considers how to solve the problem that in most existing low-voltage withdrawable switchgear, the push mechanism cannot be restricted when the drawer is not pushed all the way down, which leads to dangerous situations such as arcing and short circuits caused by the loose contact of the main contacts of the drawer due to incorrect operation by the operator. However, it does not consider how to solve the problem that the electromagnetic protection performance of the cabinet door of the existing switchgear is rapidly degraded under long-term use or harsh environment due to the inadequate sealing and shielding measures.

[0007] 4. Patent document CN109066441B discloses a low-voltage withdrawable switchgear. This document mainly considers how to solve the problem of inconvenience in moving the drawers, but does not consider how to solve the problem of external electromagnetic interference intruding along the lines and causing internal circuit faults and component malfunctions due to the lack or weakness of shielding at the inlet and outlet positions of existing switchgear. Summary of the Invention

[0008] The purpose of this invention is to provide a highly protective low-voltage withdrawable switchgear and its protection method to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a low-voltage withdrawable switchgear with high protection, comprising a cold-rolled steel plate outer shielding layer, and a double-layer shielding assembly connected to the inner side of the cold-rolled steel plate outer shielding layer, the double-layer shielding assembly being used to provide electromagnetic shielding protection for the inside of the switchgear.

[0010] The double-layer shielding assembly includes a filling gap disposed inside the outer shielding layer of the cold-rolled steel plate, and triangular absorbing rubber blocks are evenly arranged inside the filling gap. The inner side of the triangular absorbing rubber blocks is connected to the inner shielding layer of the galvanized steel plate.

[0011] The inner side of the double-layer shielding assembly has symmetrically arranged connecting slots, and a pull-out component mounting assembly is installed inside the connecting slot. The pull-out component mounting assembly is used to fix electrical components.

[0012] The pull-out component mounting assembly includes a connecting base plate installed inside the connecting groove. A metal shield is installed on the top of the connecting base plate. The side wall and bottom wall of the metal shield are respectively provided with symmetrically arranged sliding groove one and sliding groove two. A sliding plate is installed inside the sliding groove one. A fixing plate is installed between the two sets of sliding plates. A ball guide rail is installed at the bottom of the fixing plate, and the ball guide rail is installed inside the sliding groove two.

[0013] Preferably, a limiting plate is connected to the outer side of the metal shield, and the limiting plate is installed inside the connecting groove;

[0014] The contact surfaces of the limiting plate and the connecting base plate with the connecting groove are provided with a wear-resistant coating, which is a ceramic coating with a thickness of 120μm-260μm.

[0015] Preferably, the front of the metal shielding cover and the cold-rolled steel plate outer shielding layer is connected to a cabinet door shielding assembly via a hinge. The cabinet door shielding assembly is used to provide electromagnetic shielding and sealing protection for the front of the switch cabinet.

[0016] The cabinet door shielding assembly includes a cabinet door frame one and a cabinet door frame two connected by hinges to the front of the metal shielding cover and the cold-rolled steel plate outer shielding layer. Electromagnetic sealing strips are installed on the inner edges of cabinet door frame one and cabinet door frame two. A wire mesh is installed inside the electromagnetic sealing strips. Protective cabinet door one and protective cabinet door two are installed inside the wire mesh. The front of protective cabinet door one and protective cabinet door two are coated with an aluminum oxide film. The back of protective cabinet door one and protective cabinet door two are coated with a metallized polyester film. The metallized polyester film includes a polyester film base layer and a metal conductive layer vapor-deposited on one side surface of the polyester film base layer.

[0017] Handles are installed on the front of both the first and second doors of the protective cabinet.

[0018] Preferably, the conductive metal layer is a copper-zinc alloy layer with a thickness of 62nm-132nm, and the mass ratio of copper to zinc in the copper-zinc alloy layer is 3:2.

[0019] Preferably, a handle one is installed on the front of the connecting base plate, and a handle two is installed on the front of the fixing plate, with handle one located below handle two.

[0020] The surfaces of handle one, handle two and handle three are all provided with anti-slip textures. The anti-slip textures are semi-circular grooves that are evenly distributed. The radius of the semi-circular grooves is mm-mm. Shock-absorbing rubber pads are provided between handle one and the connecting base plate, between handle two and the fixing plate, and between handle three and protective cabinet door one and protective cabinet door two. The thickness of the shock-absorbing rubber pads is 3mm-8mm.

[0021] Preferably, the fixing plate, the metal shielding cover and the connecting base plate are provided with inlet and outlet holes, and inlet and outlet shielding components are installed inside the inlet and outlet holes. The inlet and outlet shielding components are used to shield electromagnetic interference signals that enter the switch cabinet through the inlet and outlet holes.

[0022] The incoming and outgoing line shielding assembly includes a stainless steel shielding sleeve installed inside the incoming and outgoing line holes, and the inside of the stainless steel shielding sleeve is filled with conductive rubber.

[0023] The stainless steel shielding sleeve is fitted with metal flanges at both ends, and the metal flanges are connected to the outer shielding layer of the cold-rolled steel plate by bolts.

[0024] Preferably, an annular sealing gasket is provided at the connection between the metal flange and the stainless steel shielding sleeve. The annular sealing gasket is made of fluororubber and has a thickness of 2mm-6mm. An outwardly protruding annular retaining edge is provided on the outer edge of the metal flange, and the height of the annular retaining edge is 3mm-7mm.

[0025] Preferably, a honeycomb brass ventilation plate is embedded in the top of the cold-rolled steel plate outer shielding layer, the double-layer shielding assembly, and the metal shielding cover, and an electromagnetic interference filter is installed at the bottom of the honeycomb brass ventilation plate.

[0026] The preferred protection method for low-voltage withdrawable switchgear is as follows:

[0027] S1. The component is mounted on top of the fixed plate using a pull-out component mounting assembly;

[0028] S2. Electromagnetic shielding protection is provided inside the switch cabinet through a double-layer shielding assembly;

[0029] S3. Electromagnetic shielding and sealing protection are provided for the front of the switchgear through the cabinet door shielding assembly;

[0030] S4. Electromagnetic interference signals entering the switch cabinet through the inlet / outlet cable shielding assembly are shielded.

[0031] Preferably, step S2 further includes the following steps:

[0032] S21. The outer shielding layer of the cold-rolled steel plate provides initial shielding against external electromagnetic interference. The triangular absorbing rubber block absorbs part of the electromagnetic radiation transmitted through the outer shielding layer of the cold-rolled steel plate within the gap.

[0033] S22. The inner shielding layer of the galvanized steel plate provides further shielding protection to the interior, and works in conjunction with the outer shielding layer of the cold-rolled steel plate and the triangular absorbing rubber block to form a multi-layer electromagnetic shielding structure.

[0034] S3 also includes the following steps:

[0035] S31. The electromagnetic sealing strip and internal wire mesh on the inner edge of the cabinet door frame enhance the structural strength and electromagnetic shielding performance, preventing electromagnetic signals from leaking from the gaps in the cabinet door.

[0036] S32. The aluminum oxide film on the front of the protective cabinet door protects the surface of the cabinet door and prevents the accumulation of surface charge, while the metallized polyester film on the back reflects and shields electromagnetic signals.

[0037] Compared with the prior art, the beneficial effects of the present invention are:

[0038] 1. This invention utilizes a double-layer shielding assembly installed inside the outer shielding layer of a cold-rolled steel plate. The triangular absorbing rubber block effectively absorbs electromagnetic radiation in specific frequency bands, complementing the outer shielding layer of the cold-rolled steel plate and the inner shielding layer of the galvanized steel plate. This creates a wide-band, multi-layered electromagnetic shielding system, significantly improving the electromagnetic shielding effectiveness inside the switchgear. Compared to existing single-shielding structures or simple combination shielding methods, this invention more accurately blocks interference signals in complex electromagnetic environments. This ensures that internal electrical components can operate stably and accurately even in strong electromagnetic interference scenarios, such as areas with concentrated large industrial electrical equipment or near communication base stations. It effectively solves the problem of poor adaptability of existing switchgear in complex electromagnetic environments, and the susceptibility to component failure and signal distortion caused by electromagnetic interference.

[0039] 2. This invention utilizes the coordinated operation of a pull-out component mounting assembly, comprising a metal shield, a sliding plate, a fixing plate, and ball bearing guides. The metal shield provides a localized, independent shielding space for the electrical components, reducing electromagnetic crosstalk between components. The sliding plate and ball bearing guides work together to allow the fixing plate to be smoothly pulled out and pushed in, facilitating component installation, maintenance, and replacement. Furthermore, it exhibits low mechanical wear and high stability during frequent operation. Compared to traditional switchgear where component installation relies heavily on simple frame fixation, resulting in clunky pull-out operations and a lack of independent shielding protection, this invention significantly improves the reliability and ease of operation of electrical components throughout their entire lifespan. It also solves the problems of poor electromagnetic compatibility and low maintenance efficiency caused by unreasonable component layout and installation structure in existing switchgear.

[0040] 3. This invention, through the installation of a cabinet door shielding component, tightly adheres the electromagnetic sealing strip on the cabinet door frame to the wire mesh, forming a dual mechanical and electromagnetic sealing barrier. This prevents electromagnetic signals from leaking through even the smallest door gaps. The alumina film protecting the cabinet door possesses high insulation and corrosion resistance, preventing the accumulation of static charge on the door surface and the risk of discharge. The metallized polyester film efficiently shields external electromagnetic waves based on the principle of electromagnetic reflection. Compared to existing switchgear doors that rely solely on simple sealing strips and door panels for protection, this component significantly improves the electromagnetic shielding integrity and durability at the cabinet door, effectively solving the problem of rapid degradation of electromagnetic protection performance in existing switchgear doors due to inadequate sealing and shielding measures under long-term use or harsh environments.

[0041] 4. This invention utilizes an inlet / outlet shielding assembly installed within the inlet / outlet ports. The stainless steel shielding sleeve, combined with internal conductive rubber, effectively absorbs and shields electromagnetic interference signals transmitted through the inlet / outlet lines. The robust connection between the metal flange and the cold-rolled steel outer shielding layer ensures the integrity of the shielding structure and the reliability of grounding. Compared to existing switchgear that uses only ordinary sleeves or simple shielding rings at the inlet / outlet points, this assembly comprehensively resists external electromagnetic interference from coupling into the switchgear through the lines. This ensures the purity of internal signal transmission and protects electrical components from electromagnetic shocks introduced by the lines. It effectively solves the problem of external electromagnetic interference intruding along the lines and causing internal circuit faults and component malfunctions due to insufficient or weak shielding at the inlet / outlet points of existing switchgear. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0043] Figure 2 This is a cross-sectional structural diagram of the present invention;

[0044] Figure 3 This is a schematic diagram of the double-layer shielding component structure of the present invention;

[0045] Figure 4 This is a schematic diagram of the pull-out component mounting assembly structure of the present invention;

[0046] Figure 5 This is a schematic diagram of the internal structure of the metal shielding cover of the present invention;

[0047] Figure 6 This is a schematic diagram of the cabinet door shielding assembly structure of the present invention;

[0048] Figure 7 This is a schematic diagram of the fixing plate structure of the present invention;

[0049] Figure 8 This is a flowchart illustrating the protection process of the present invention.

[0050] In the diagram: 1. Cold-rolled steel outer shielding layer; 2. Triangular absorbing rubber block; 3. Galvanized steel inner shielding layer; 4. Connecting groove; 5. Connecting base plate; 6. Metal shielding cover; 7. Sliding groove one; 8. Sliding groove two; 9. Sliding plate; 10. Fixing plate; 11. Limiting plate; 12. Cabinet door frame one; 13. Protective cabinet door one; 14. Alumina film; 15. Metallized polyester film; 16. Cable entry / exit hole; 17. Honeycomb brass ventilation plate; 18. Cabinet door frame two; 19. Protective cabinet door two. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0052] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device 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 invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0053] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 7 and Figure 8 The present invention provides an embodiment of a low-voltage withdrawable switchgear with high protection, comprising a cold-rolled steel plate outer shielding layer 1, and a double-layer shielding assembly connected to the inner side of the cold-rolled steel plate outer shielding layer 1, the double-layer shielding assembly being used to provide electromagnetic shielding protection for the inside of the switchgear.

[0055] The double-layer shielding assembly includes a filling gap disposed inside the outer shielding layer 1 of cold-rolled steel plate, and triangular absorbing rubber blocks 2 are evenly arranged inside the filling gap. The inner side of the triangular absorbing rubber blocks 2 is connected to the inner shielding layer 3 of galvanized steel plate.

[0056] The inner side of the double-layer shielding assembly is provided with symmetrically arranged connecting slots 4. A pull-out component mounting assembly is installed inside the connecting slots 4. The pull-out component mounting assembly is used to fix electrical components.

[0057] The pull-out component mounting assembly includes a connecting base plate 5 installed inside the connecting groove 4. A metal shield 6 is installed on the top of the connecting base plate 5. The side wall and bottom wall of the metal shield 6 are respectively provided with symmetrically arranged sliding groove 1 7 and sliding groove 2 8. A sliding plate 9 is installed inside the sliding groove 1 7. A fixing plate 10 is installed between the two sets of sliding plates 9. A ball guide rail is installed at the bottom of the fixing plate 10, and the ball guide rail is installed inside the sliding groove 2 8.

[0058] Furthermore, the cold-rolled steel outer shielding layer 1 withstands the mechanical impact of the external environment and performs initial electromagnetic protection tasks, providing support and a basic protective framework for the internal double-layer shielding components. The gaps provide installation space for the triangular absorbing rubber blocks 2, which are arranged in a uniform distribution. The triangular shape increases the contact area and density of the rubber blocks within the gaps, improving space utilization. The triangular absorbing rubber blocks 2 absorb electromagnetic radiation in specific frequency bands, especially the low-to-medium frequency electromagnetic interference commonly found in industrial environments. They can convert some of the electromagnetic radiation passing through the cold-rolled steel outer shielding layer 1 into heat or other forms of energy, effectively reducing the amount of electromagnetic interference entering deeper into the switchgear, further purifying the internal electromagnetic environment, and reducing the potential impact of electromagnetic interference on electrical components.

[0059] The galvanized steel inner shielding layer 3, as the inner shielding layer of the double-layer shielding assembly, works in conjunction with the cold-rolled steel outer shielding layer 1 and the triangular absorbing rubber block 2. It can further shield and reflect any residual electromagnetic signals that may still exist after the previous two treatments, more effectively isolating internal electrical components from the external electromagnetic environment. This forms a multi-layered electromagnetic shielding structure, greatly improving the overall electromagnetic shielding effectiveness inside the switchgear and ensuring that electrical components operate in a relatively pure electromagnetic environment.

[0060] The connecting slots 4 are symmetrically arranged inside the double-layer shielding assembly. Their shape and size match the connecting base plate 5. The connecting slots 4 serve to connect and support the pull-out component mounting assembly, so that the mounting assembly can be firmly installed inside the double-layer shielding assembly. In addition, during the installation, removal and maintenance of electrical components, they provide a stable track and space constraint for the movement of the assembly, ensuring the smoothness and accuracy of the operation process.

[0061] The connecting base plate 5 provides a stable mounting surface for the metal shield 6 and electrical components, evenly distributing the weight of the electrical components on the connecting groove 4. It also assists in the electromagnetic conduction and grounding of the entire shielding system through its own conductivity, ensuring the firmness of the electrical component installation and the reliability of the electrical connection. At the same time, it provides a smooth moving base in conjunction with the connecting groove 4 during the extraction operation.

[0062] The metal shield 6 provides a locally independent shielding space for the internally installed electrical components, reducing electromagnetic crosstalk between components. The metal shield 6 encloses the electrical components, forming a relatively independent electromagnetic environment, preventing the electromagnetic signals generated by the components themselves from leaking out and affecting other components, while also blocking external electromagnetic interference from entering the shield and affecting the normal operation of the components.

[0063] Sliding groove 7 and sliding groove 8 provide guidance for the sliding plate 9 and the ball bearing guide, enabling the fixed plate 10 to be smoothly pulled out and pushed forward in a predetermined direction within the metal shield 6. This reduces the frictional resistance during the movement of the fixed plate 10, while also reducing mechanical wear caused by friction, thus improving the service life and operational reliability of the pull-out component mounting assembly.

[0064] Please see Figure 2 , Figure 4 and Figure 5 The present invention provides an embodiment of a low-voltage withdrawable switch cabinet with high protection, wherein the outer side of the metal shield 6 is connected to a limiting plate 11, and the limiting plate 11 is installed inside the connecting groove 4.

[0065] The contact surfaces of the limiting plate 11 and the connecting base plate 5 with the connecting groove 4 are provided with a wear-resistant coating. The wear-resistant coating is a ceramic coating with a thickness of 120μm-260μm.

[0066] Furthermore, the limiting plate 11 is connected to the outside of the metal shielding cover 6 and installed inside the connecting groove 4. The shape of the limiting plate 11 is adapted to the contour of the connecting groove 4 to ensure the stability and reliability of the metal shielding cover 6 under various forces. When the pull-out component mounting assembly is pulled out or pushed in the connecting groove 4, the limiting plate 11 can prevent the metal shielding cover 6 from excessive lateral displacement due to uneven force or improper operation, ensuring that it always runs smoothly along the predetermined track. At the same time, when the switch cabinet is subjected to external vibration or impact, the limiting plate 11 can evenly distribute the force to the connecting groove 4, enhancing the seismic resistance and stability of the entire structure, ensuring that the internal electrical components are not damaged or adversely affected by displacement, and maintaining the reliability and stability of the electrical connection.

[0067] The wear-resistant coating is made of ceramic material and is uniformly applied to the contact surfaces of the limiting plate 11 and the connecting base plate 5 with the connecting groove 4. During long-term use, the pull-out component mounting assembly requires frequent pulling and pushing operations within the connecting groove 4, inevitably leading to friction between the contact surfaces of the components. The presence of the wear-resistant ceramic coating significantly reduces wear caused by this friction on the component surfaces. It effectively resists scratches, abrasions, and wear caused by friction, extending the service life of the limiting plate 11, the connecting base plate 5, and the connecting groove 4, and reducing the frequency of component replacement and maintenance costs due to wear. Simultaneously, the high hardness and chemical stability of the ceramic coating prevent corrosion caused by metal surface wear in humid or corrosive environments, further protecting the integrity of the internal structure and the stability of the electrical performance of the switchgear. This ensures reliable operation of the switchgear under various working conditions, continuously providing a good protective and support environment for electrical components.

[0068] Please see Figure 1 and Figure 4 The present invention provides an embodiment of a low-voltage withdrawable switchgear with high protection, wherein the front of the metal shielding cover 6 and the cold-rolled steel plate outer shielding layer 1 are connected by a cabinet door shielding assembly via a hinge, and the cabinet door shielding assembly is used to provide electromagnetic shielding and sealing protection for the front of the switchgear.

[0069] The cabinet door shielding assembly includes a cabinet door frame 12 and a cabinet door frame 2 18 connected to the front of the metal shielding cover 6 and the cold-rolled steel plate outer shielding layer 1 by hinges. Electromagnetic sealing strips are installed on the inner edges of the cabinet door frame 12 and the cabinet door frame 2 18. A wire mesh is provided inside the electromagnetic sealing strips. Protective cabinet door 13 and protective cabinet door 2 19 are installed inside the wire mesh. The front of the protective cabinet door 13 and the protective cabinet door 2 19 is coated with an aluminum oxide film 14. The back of the protective cabinet door 13 and the protective cabinet door 2 19 is coated with a metallized polyester film 15. The metallized polyester film 15 includes a polyester film base layer and a metal conductive layer vapor-deposited on one side surface of the polyester film base layer.

[0070] Handles are installed on the front of the protective cabinet door 13 and the protective cabinet door 29.

[0071] The conductive metal layer is a copper-zinc alloy layer with a thickness of 62nm-132nm, and the mass ratio of copper to zinc in the copper-zinc alloy layer is 3:2.

[0072] Furthermore, cabinet door frame 12 and cabinet door frame 18 are respectively connected to the front of the metal shielding cover 6 and the cold-rolled steel outer shielding layer 1 via hinges, forming the frame structure of the front of the switchgear. Cabinet door frame 12 and cabinet door frame 18 serve as the supporting frame for protective cabinet doors 13 and 19, providing a stable structural foundation for the entire cabinet door shielding assembly. The connection with the metal shielding cover 6 and the cold-rolled steel outer shielding layer 1 ensures the integrity and continuity of the entire switchgear's electromagnetic shielding structure when the cabinet door is closed, effectively preventing electromagnetic signals from leaking from the gaps on the front.

[0073] Electromagnetic sealing strips are installed on the inner edge of the cabinet door frame, with steel wire mesh embedded inside. Utilizing the elastic deformation capability of the electromagnetic sealing strips, they are compressed when protective cabinet doors 13 and 19 are closed, filling the tiny gaps between protective cabinet doors 13 and 19 and cabinet door frames 12 and 18, forming a mechanical seal to prevent dust or moisture and other impurities from entering the switchgear. Simultaneously, due to the presence of the internal steel wire mesh and its own conductivity, it can effectively conduct and shield electromagnetic signals. Working in conjunction with the metallized polyester film 15 of protective cabinet doors 13 and 19, it enhances the overall electromagnetic shielding performance of the cabinet doors, forming the first line of defense against electromagnetic interference and reducing the possibility of electromagnetic interference entering the switchgear through the door gaps.

[0074] The aluminum oxide film 14 has high insulation and good corrosion resistance, forming an insulating barrier to prevent dust and impurities from being adsorbed on the surface of the cabinet door due to static electricity accumulation. At the same time, it avoids safety hazards caused by electrostatic discharge, protects the smoothness and integrity of the surfaces of protective cabinet door 13 and protective cabinet door 2 19, extends the service life of protective cabinet door 13 and protective cabinet door 2 19, and maintains the stability of their electromagnetic shielding performance.

[0075] The metallized polyester film 15 includes a polyester film base layer and a metal conductive layer vapor-deposited on one side of the polyester film base layer. The polyester film base layer provides good flexibility and mechanical support, while the copper-zinc alloy layer with a thickness of 62nm-132nm and a copper-zinc mass ratio of 3:2 vapor-deposited on one side of the base layer serves as the metal conductive layer, exhibiting good conductivity and electromagnetic reflection characteristics. The metal conductive layer can efficiently reflect and shield external electromagnetic interference signals, reflecting most of the electromagnetic energy back to the external environment. Together with the electromagnetic sealing strip, wire mesh, metal shielding cover 6, and cold-rolled steel plate outer shielding layer 1, it constitutes a multi-layered electromagnetic shielding system, ensuring that the electrical components inside the switchgear are protected from external electromagnetic interference. Handle 3 is installed on the front of protective cabinet door 13 and protective cabinet door 29, facilitating the opening and closing of the cabinet doors by operators.

[0076] Please see Figure 1 , Figure 2 , Figure 4 , Figure 5 and Figure 7 The present invention provides an embodiment of a low-voltage withdrawable switch cabinet with high protection, wherein a handle one is installed on the front of the connecting base plate 5, a handle two is installed on the front of the fixing plate 10, and the handle one is located below the handle two.

[0077] The surfaces of handle one, handle two and handle three are all provided with anti-slip textures. The anti-slip textures are semi-circular grooves that are evenly distributed. The radius of the semi-circular grooves is 2mm-5mm. Shock-absorbing rubber pads are provided between handle one and the connecting base plate 5, between handle two and the fixing plate 10, and between handle three and the first protective cabinet door 13 and the second protective cabinet door 19. The thickness of the shock-absorbing rubber pads is 3mm-8mm.

[0078] Furthermore, handle one is installed on the front of the connecting base plate 5, and handle two is installed on the front of the fixing plate 10, arranged vertically. The anti-slip texture on the surface consists of equally spaced semi-circular grooves. These grooves have a moderate depth and a radius between 2mm and 5mm, which can effectively increase the friction between the hand and the handle without causing discomfort to the hand.

[0079] Handle 1 provides a leverage point for pulling out or pushing in the connecting base plate 5 and its accessories, facilitating operation and allowing the connecting base plate 5 to move smoothly within the connecting groove 4. Handle 2 is used for similar operations on the fixing plate 10, especially when maintenance, replacement, or adjustment of electrical components mounted on the fixing plate 10 is required. By pulling handle 2, the fixing plate 10 can be easily pulled out from the metal shielding cover 6, improving the convenience and efficiency of operation.

[0080] Please see Figure 7 The present invention provides an embodiment of a low-voltage withdrawable switchgear with high protection. The fixing plate 10, the metal shielding cover 6 and the connecting base plate 5 are provided with inlet and outlet holes 16. An inlet and outlet shielding component is installed inside the inlet and outlet hole 16. The inlet and outlet shielding component is used to shield electromagnetic interference signals that enter the switchgear through the inlet and outlet hole 16.

[0081] The incoming and outgoing line shielding assembly includes a stainless steel shielding sleeve installed inside the incoming and outgoing line hole 16, and the inside of the stainless steel shielding sleeve is filled with conductive rubber.

[0082] Metal flanges are installed at both ends of the stainless steel shielding sleeve, and the metal flanges are connected to the outer shielding layer 1 of the cold-rolled steel plate by bolts.

[0083] An annular sealing gasket is provided at the connection between the metal flange and the stainless steel shielding sleeve. The annular sealing gasket is made of fluororubber and has a thickness of 2mm-6mm. The outer edge of the metal flange is provided with an outwardly protruding annular retaining edge with a height of 3mm-7mm.

[0084] Furthermore, stainless steel shielding sleeves are installed inside the cable entry / exit holes 16 of the fixed plate 10, the metal shielding cover 6, and the connecting base plate 5. Serving as the main electromagnetic shielding channel for incoming and outgoing lines, the stainless steel shielding sleeves effectively block external electromagnetic interference signals from being conducted along the cables into the switchgear. Their metallic material reflects and absorbs electromagnetic waves, confining most interference signals outside the sleeves, thereby protecting the electrical components inside the switchgear from electromagnetic interference introduced by the lines.

[0085] Conductive rubber is filled inside the stainless steel shielding sleeve. For weak electromagnetic interference signals that penetrate the stainless steel shielding sleeve, the conductive rubber can further absorb and attenuate them. When electromagnetic interference waves enter the conductive rubber, its internal conductive network induces current in the electromagnetic waves. This current is converted into heat or other forms of energy and dissipated within the conductive rubber, thus achieving secondary shielding against electromagnetic interference. This significantly improves the electromagnetic shielding effect at the 16 inlet / outlet holes, ensuring the purity of the signals entering the switchgear.

[0086] Metal flanges are installed at both ends of the stainless steel shielding sleeve and connected to the cold-rolled steel outer shielding layer 1 by bolts. On one hand, the metal flanges fix the stainless steel shielding sleeve, ensuring its stable position within the inlet / outlet holes 16 and preventing displacement or loosening due to external forces. On the other hand, as part of the electromagnetic shielding structure, it connects the stainless steel shielding sleeve and the cold-rolled steel outer shielding layer 1 into a complete electrical path, allowing the electromagnetic shielding effect to be better conducted and synergistically utilized throughout the entire switchgear shielding system. Through a reliable connection with the cold-rolled steel outer shielding layer 1, electromagnetic interference signals that may leak onto the metal flange can be promptly grounded, further enhancing the reliability of the electromagnetic shielding.

[0087] The annular sealing gasket, located at the connection between the metal flange and the stainless steel shielding sleeve, is made of fluororubber and possesses excellent chemical corrosion resistance, high and low temperature resistance, and good elasticity and sealing performance. Its thickness ranges from 2mm to 6mm, forming a tight sealing layer between the metal flange and the stainless steel shielding sleeve. This prevents external dust, moisture, and other impurities from entering the inlet / outlet port 16 through the gap between the metal flange and the stainless steel shielding sleeve, avoiding potential safety hazards such as affecting the electromagnetic shielding performance of the conductive rubber or causing short circuits due to impurity accumulation. Simultaneously, the good sealing performance also helps maintain the electromagnetic shielding integrity of the entire inlet / outlet shielding assembly, preventing electromagnetic interference signals from leaking or intruding through these gaps.

[0088] The annular retaining edge is located on the outer edge of the metal flange, protruding outwards with a height of 3mm-7mm. It protects the connection between the metal flange and the stainless steel shielding sleeve from accidental impacts or damage, ensuring the reliability and stability of the connection. Simultaneously, the annular retaining edge helps guide any dust, water droplets, or other impurities to slide off along its edge, reducing accumulation at the connection point. This further assists the annular sealing gasket in maintaining a good seal and protective effect, ensuring the normal operation of the incoming and outgoing line shielding components and the continued effectiveness of the electromagnetic shielding function.

[0089] Please see Figure 1 , Figure 4 and Figure 5 One embodiment of the present invention is a low-voltage withdrawable switchgear with high protection, wherein a honeycomb brass ventilation plate 17 is embedded in the top of the cold-rolled steel plate outer shielding layer 1, the double-layer shielding assembly and the metal shielding cover 6, and an electromagnetic interference filter is installed at the bottom of the honeycomb brass ventilation plate 17.

[0090] Furthermore, the primary function of the honeycomb brass ventilation plate 17 is to provide ventilation and heat dissipation channels for the inside of the switchgear. During the operation of electrical components, heat is generated. If this heat cannot be dissipated in time, it can lead to excessively high component temperatures, affecting their performance and lifespan, and may even cause malfunctions. The honeycomb brass ventilation plate 17, through natural air convection or forced convection with the assistance of ventilation equipment, exhausts hot air from inside the switchgear and introduces cool air from outside, maintaining the internal temperature within a suitable range and ensuring the normal operating environment of the electrical components. Simultaneously, due to the conductivity of brass, the ventilation plate also participates in the electromagnetic shielding system of the entire switchgear. It can shield against electromagnetic interference that may intrude from the top, working in conjunction with the cold-rolled steel outer shielding layer 1, the double-layer shielding assembly, and the metal shielding cover 6 to prevent external electromagnetic signals from entering the switchgear through the ventilation openings, ensuring the stability of the internal electromagnetic environment and avoiding adverse effects of electromagnetic interference on electrical components.

[0091] An electromagnetic interference (EMI) filter is installed at the bottom of the honeycomb brass ventilation plate 17 to further filter and purify EMI signals entering the switchgear through the honeycomb brass ventilation plate 17. Although the honeycomb brass ventilation plate 17 already has a certain electromagnetic shielding capability, some EMI signals may still penetrate through it. The EMI filter can target these residual interference signals according to their frequency characteristics. For high-frequency EMI, capacitors play a major role, bypassing high-frequency signals to ground through the charging and discharging process; for low-frequency EMI, inductors attenuate and filter low-frequency signals by impeding current changes. Through the action of the EMI filter, the EMI signals entering the switchgear can be reduced to an extremely low level, maximizing the protection of the normal operation of internal electrical components, improving the overall switchgear's anti-interference capability in complex electromagnetic environments, ensuring the stability and reliability of the electrical system, and reducing the occurrence of signal distortion, malfunctions, and other problems caused by EMI.

[0092] Working principle: The outer shielding layer 1 of cold-rolled steel plate serves as the outermost layer of protection for the switch cabinet. It mainly utilizes the good conductivity and magnetic permeability of cold-rolled steel plate to initially shield and block external electromagnetic interference, reflecting or absorbing most of the electromagnetic radiation and reducing the amount of electromagnetic interference entering the switch cabinet.

[0093] The triangular absorbing rubber block 2 is located in the filling gap. When electromagnetic radiation passes through the outer shielding layer 1 of the cold-rolled steel plate, the triangular absorbing rubber block 2 can convert electromagnetic energy into other forms of energy such as heat energy, thereby absorbing part of the electromagnetic radiation and further weakening the intensity of electromagnetic interference entering the interior.

[0094] The inner shielding layer 3 of the galvanized steel sheet, together with the outer shielding layer 1 of the cold-rolled steel sheet and the triangular absorbing rubber block 2, work together to provide further shielding protection for the interior. The galvanized steel sheet has good conductivity, which can reflect and absorb residual electromagnetic radiation, forming a multi-layer electromagnetic shielding structure that effectively protects the electrical components inside the switchgear from external electromagnetic interference.

[0095] The base plate 5 serves as the mounting foundation, providing stable support and a fixed position for the metal shielding cover 6 and other components, ensuring the structural stability and reliability of the entire mounting assembly. The metal shielding cover 6 provides local electromagnetic shielding for the electrical components installed inside. Through its own metal material and enclosed structure, it limits the electromagnetic radiation generated by the electrical components to a certain range, preventing it from interfering with other components or the external environment, while also blocking the influence of external electromagnetic interference on the internal components.

[0096] Sliding groove 7 and sliding groove 8 provide sliding tracks for sliding plate 9, allowing fixed plate 10 to slide flexibly within metal shielding cover 6, facilitating the extraction and insertion of electrical components while maintaining good electrical connection and shielding effect during sliding. The installation of ball bearing guides further reduces sliding friction, making operation smoother.

[0097] The steel wire mesh inside the electromagnetic sealing strips on the inner edges of cabinet door frame 12 and cabinet door frame 28 enhances the structural strength of the strips, allowing them to better fill the gaps when cabinet door 13 and cabinet door 219 are closed. At the same time, the steel wire mesh itself also has a certain electromagnetic shielding performance, working together with the electromagnetic sealing strips to prevent electromagnetic signals from leaking from the gaps in cabinet door 13 and cabinet door 219, thus ensuring the electromagnetic shielding effect on the front of the switch cabinet.

[0098] The aluminum oxide film 14 on the front of the protective cabinet door 13 and the protective cabinet door 2 has good insulation properties and chemical stability, which can protect the surface of the protective cabinet door 13 and the protective cabinet door 2 from external physical damage and chemical corrosion. At the same time, it can also prevent the accumulation of surface charge and avoid damage to electrical components caused by electrostatic discharge due to charge accumulation.

[0099] The metal conductive layer in the metallized polyester film 15 on the back of the protective cabinet door 13 and the protective cabinet door 2 19 can reflect and shield electromagnetic signals. When external electromagnetic radiation shines on the cabinet door, the metal conductive layer reflects most of the electromagnetic signal back, further enhancing the electromagnetic shielding performance of the cabinet door and protecting the electrical components inside the switch cabinet.

[0100] Stainless steel shielding sleeves are installed inside the inlet / outlet hole 16. Utilizing the good conductivity of stainless steel, they shield electromagnetic interference signals that enter the switch cabinet through the inlet / outlet hole 16, preventing external electromagnetic interference from entering the switch cabinet through the lines. At the same time, they also prevent electromagnetic signals inside the switch cabinet from radiating outward through the lines.

[0101] The conductive rubber filling inside the stainless steel shielding sleeve has good conductivity and elasticity, which can fill the gap between the stainless steel shielding sleeve and the line, ensuring good electrical contact and further enhancing the electromagnetic shielding effect. At the same time, it can also play a role in shock absorption or sealing, preventing electromagnetic interference from entering or leaking through the gap.

[0102] The metal flange is connected to the outer shielding layer 1 of the cold-rolled steel plate by bolts. On the one hand, it fixes the position of the stainless steel shielding sleeve and ensures its stable installation at the inlet and outlet holes 16. On the other hand, an annular sealing gasket is provided at the connection between the metal flange and the stainless steel shielding sleeve to ensure the sealing of the connection and prevent electromagnetic interference from entering the switch cabinet from the connection.

[0103] The honeycomb brass ventilation plate 17, while ensuring ventilation and heat dissipation, also provides some blocking and reflection of electromagnetic radiation, preventing external electromagnetic interference from entering the switchgear through the ventilation openings. An electromagnetic interference filter, installed at the bottom of the honeycomb brass ventilation plate 17, filters electromagnetic interference signals entering through the ventilation openings, removing high-frequency components and allowing only normal operating frequency signals to pass through. This further improves the electromagnetic environment quality inside the switchgear and protects the normal operation of electrical components.

[0104] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A highly protective low-voltage withdrawable switchgear, comprising a cold-rolled steel outer shielding layer (1), characterized in that: The inner side of the cold-rolled steel plate outer shielding layer (1) is connected to a double-layer shielding assembly, which is used to provide electromagnetic shielding protection for the inside of the switch cabinet. The double-layer shielding assembly includes a filling gap disposed inside the outer shielding layer (1) of cold-rolled steel plate, and triangular absorbing rubber blocks (2) are uniformly arranged inside the filling gap. The inner side of the triangular absorbing rubber blocks (2) is connected to the inner shielding layer (3) of galvanized steel plate. The inner side of the double-layer shielding assembly is provided with symmetrically arranged connecting slots (4), and a pull-out component mounting assembly is installed inside the connecting slots (4). The pull-out component mounting assembly is used to fix electrical components. The pull-out component mounting assembly includes a connecting base plate (5) installed inside the connecting groove (4), a metal shield (6) installed on the top of the connecting base plate (5), and symmetrically arranged sliding grooves one (7) and two sliding grooves (8) respectively opened on the side wall and bottom wall of the metal shield (6). A sliding plate (9) is installed inside the sliding groove one (7), and a fixing plate (10) is installed between the two sets of sliding plates (9). A ball guide rail is installed at the bottom of the fixing plate (10), and the ball guide rail is installed inside the sliding groove two (8). The front of the metal shielding cover (6) and the cold-rolled steel plate outer shielding layer (1) are connected to the cabinet door shielding assembly by hinges. The cabinet door shielding assembly is used to provide electromagnetic shielding and sealing protection for the front of the switch cabinet. The cabinet door shielding assembly includes a cabinet door frame one (12) and a cabinet door frame two (18) connected to the front of the metal shielding cover (6) and the cold-rolled steel plate outer shielding layer (1) by hinges. Electromagnetic sealing strips are installed on the inner edges of the cabinet door frame one (12) and the cabinet door frame two (18). A wire mesh is provided inside the electromagnetic sealing strips. Protective cabinet door one (13) and protective cabinet door two (19) are installed on the inner side of the wire mesh. An aluminum oxide film (14) is coated on the front of the protective cabinet door one (13) and the protective cabinet door two (19). A metallized polyester film (15) is coated on the back of the protective cabinet door one (13) and the protective cabinet door two (19). The metallized polyester film (15) includes a polyester film base layer and a metal conductive layer vapor-deposited on one side surface of the polyester film base layer. Handles are installed on the front of the first (13) and second (19) protective cabinet doors; The conductive metal layer is a copper-zinc alloy layer with a thickness of 62nm-132nm, and the mass ratio of copper to zinc in the copper-zinc alloy layer is 3:

2.

2. The low-voltage withdrawable switchgear with high protection according to claim 1, characterized in that: The outer side of the metal shield (6) is connected to a limiting plate (11), and the limiting plate (11) is installed inside the connecting groove (4); The contact surfaces of the limiting plate (11) and the connecting base plate (5) with the connecting groove (4) are provided with a wear-resistant coating. The wear-resistant coating is a ceramic coating with a thickness of 120μm-260μm.

3. The low-voltage withdrawable switchgear with high protection according to claim 1, characterized in that: The front of the connecting base plate (5) is equipped with a handle one, and the front of the fixing plate (10) is equipped with a handle two, with the handle one located below the handle two. The surfaces of handle one, handle two and handle three are all provided with anti-slip textures. The anti-slip textures are semi-circular grooves that are evenly distributed. The radius of the semi-circular grooves is 2mm-5mm. Shock-absorbing rubber pads are provided between handle one and the connecting base plate (5), between handle two and the fixing plate (10), and between handle three and the first protective cabinet door (13) and the second protective cabinet door (19). The thickness of the shock-absorbing rubber pads is 3mm-8mm.

4. A high-protection low-voltage withdrawable switchgear according to claim 1, characterized in that: The fixed plate (10), the metal shield (6) and the connecting base plate (5) are provided with inlet and outlet holes (16). Inlet and outlet shielding components are installed inside the inlet and outlet holes (16). The inlet and outlet shielding components are used to shield electromagnetic interference signals that enter the switch cabinet through the inlet and outlet holes (16). The inlet and outlet shielding assembly includes a stainless steel shielding sleeve installed inside the inlet and outlet hole (16), and the inside of the stainless steel shielding sleeve is filled with conductive rubber. Metal flanges are installed at both ends of the stainless steel shielding sleeve, and the metal flanges are connected to the outer shielding layer (1) of the cold-rolled steel plate by bolts.

5. A high-protection low-voltage withdrawable switchgear according to claim 4, characterized in that: An annular sealing gasket is provided at the connection between the metal flange and the stainless steel shielding sleeve. The annular sealing gasket is made of fluororubber and has a thickness of 2mm-6mm. The outer edge of the metal flange is provided with an outwardly protruding annular retaining edge with a height of 3mm-7mm.

6. A high-protection low-voltage withdrawable switchgear according to claim 1, characterized in that: The top of the cold-rolled steel plate outer shielding layer (1), the double-layer shielding assembly and the metal shielding cover (6) is inlaid with a honeycomb brass ventilation plate (17), and an electromagnetic interference filter is installed at the bottom of the honeycomb brass ventilation plate (17).

7. A protection method for a low-voltage withdrawable switchgear with high protection according to any one of claims 1-6, characterized in that, The protection methods for low-voltage withdrawable switchgear are as follows: S1. The component is mounted on top of the fixed plate (10) by means of the pull-out component mounting assembly; S2. Electromagnetic shielding protection is provided inside the switch cabinet through a double-layer shielding assembly; S3. Electromagnetic shielding and sealing protection are provided for the front of the switchgear through the cabinet door shielding assembly; S4. Electromagnetic interference signals entering the switch cabinet through the inlet / outlet cable shielding assembly are shielded.

8. The protection method for a high-protection low-voltage withdrawable switchgear according to claim 7, characterized in that: S2 also includes the following steps: S21. The outer shielding layer (1) of the cold-rolled steel plate provides initial shielding against external electromagnetic interference. The triangular absorbing rubber block (2) absorbs part of the electromagnetic radiation transmitted through the outer shielding layer (1) of the cold-rolled steel plate within the gap. S22. The inner shielding layer (3) of the galvanized steel plate provides shielding protection for the interior again. Together with the outer shielding layer (1) of the cold-rolled steel plate and the triangular absorbing rubber block (2), it forms a multi-layer electromagnetic shielding structure. S3 also includes the following steps: S31. The electromagnetic sealing strip and internal wire mesh on the inner edge of the cabinet door frame enhance the structural strength and electromagnetic shielding performance, preventing electromagnetic signals from leaking from the gaps in the cabinet door. S32. The aluminum oxide film (14) on the front of the protective cabinet door protects the surface of the cabinet door and prevents the accumulation of surface charge, while the metallized polyester film (15) on the back reflects and shields electromagnetic signals.

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