Power conversion device and charging pile
By combining a ring-shaped structural component with potting compound for sealing, the problem of electrolytic capacitors splashing under instantaneous overvoltage is solved, thus improving the safety and reliability of the charging equipment.
Patent Information
- Application Number
- CN202421984377.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-15
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2034-08-15
AI Technical Summary
When existing electrolytic capacitors are broken down by instantaneous overvoltage, the electrolyte may splash out, causing contamination of other electrical components and posing safety risks.
A combination of ring-shaped structural components and potting compound is used to create a fully enclosed space to prevent electrolyte splashing, including sealing the top and circumference of the electrolytic capacitor.
It effectively prevents electrolyte splashing, avoids the spread of faults, improves the safety of charging equipment, and prevents other devices from being affected by electrolyte.
Smart Images
Figure CN223514618U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy technology, and in particular to an electric power conversion device and a charging pile. Background Technology
[0002] Electrolytic capacitors are electronic components used to store electrical charge and energy, and are commonly used in the power modules of charging equipment such as charging piles. The anode of an electrolytic capacitor is a metal foil, the dielectric is an oxide film tightly attached to the anode, and the cathode is composed of conductive materials, electrolyte, and other materials. The electrolyte is the main component of the cathode.
[0003] In existing technologies, the electrolyte in electrolytic capacitors may be a liquid electrolyte. When an electrolytic capacitor is broken down by a momentary overvoltage, the electrolyte will splash out, which may contaminate other electrical components and pose a safety risk. Utility Model Content
[0004] This application provides a power conversion device and a charging pile. The power conversion device can provide good sealing protection for the electrolyte of the electrolytic capacitor, preventing the electrolyte from splashing after the capacitor breaks down, thereby preventing the fault from spreading.
[0005] In a first aspect, embodiments of this application provide a power conversion device, which includes a housing, a substrate, an annular structural member, a power device, and at least one electrolytic capacitor. The power device and the at least one electrolytic capacitor can be connected via the substrate to form a single power conversion circuit. This power conversion device can be applied to charging equipment such as charging piles. The housing includes a bottom shell and a frame, which together enclose a receiving space. The substrate has opposing first and second surfaces. The feet of each electrolytic capacitor are fixed to the first surface of the substrate. The first surface of the substrate faces the bottom shell and is fixed to the frame to accommodate the electrolytic capacitor within the receiving space. A potting compound is filled between the electrolytic capacitor and the bottom shell to seal the top of the electrolytic capacitor. The annular structural member circumferentially surrounds the at least one electrolytic capacitor. One end of the annular structural member facing the substrate is fixed to the substrate, and the other end of the annular structural member facing the bottom shell extends into the receiving space of the housing and is fixed to the potting compound. The annular structural member can seal the circumference of the electrolytic capacitor. For the at least one electrolytic capacitor, a sealed space can be formed between the first surface of the substrate, the inner wall of the annular structure, and the potting compound, thereby providing all-round structural protection for the at least one electrolytic capacitor.
[0006] In the aforementioned power conversion device, when the electrolytic capacitor is momentarily overvoltaged and breaks down, the potting compound and the ring-shaped structural component provide protection from the top and circumference of the electrolytic capacitor, preventing electrolyte leakage outside the enclosure. This suppresses fault propagation and prevents electrolyte spillage from posing a safety risk to other components. Because the electrolytic capacitor prevents electrolyte splashing and leakage when it breaks down due to momentary overvoltage, it also prevents other power components in the power conversion device from being affected by the electrolyte, thus preventing arcing, sparking, and other phenomena, thereby preventing secondary faults and fault propagation.
[0007] In one possible implementation, the radially extending annular structure of the electrolytic capacitor extends from one end toward the substrate to between the substrate and the end face of the frame toward the substrate, with the length of the end of the annular structure toward the substrate being greater than the length of the end of the annular structure toward the bottom shell. The end of the annular structure toward the substrate can extend between the end face of the substrate and the end face of the frame toward the substrate, improving the stability and reliability of the connection between the annular structure and the substrate.
[0008] In one possible implementation, the end of the annular structure facing the substrate includes a surface facing the frame. This surface includes a plurality of bosses spaced circumferentially along the annular structure. When the annular structure mates with the housing, each boss abuts against the end face of the frame facing the substrate. The multiple bosses can enhance the robustness of the structural fit between the annular structure and the frame.
[0009] In one possible implementation, the substrate and the frame of the housing are connected to the substrate-facing end face via multiple connectors. The annular structural member includes clearance notches, each clearance notch being used to pass through a connector without affecting the connection and fixation between the substrate and the frame. Along the circumference of the annular structural member, the clearance notches and bosses are spaced apart, such that the clearance notches can avoid the bosses.
[0010] In one possible implementation, the inner wall of the annular structural member is formed with multiple recesses, each recess corresponding to a protrusion along the wall thickness direction of the annular structural member. This can ensure that the wall thickness of the annular structural member remains relatively uniform and improve the uniformity of the structural stress distribution.
[0011] In one possible implementation, a flexible support member is provided between at least one contact point between the substrate and the frame and the annular structural member. Specifically, a flexible support member can be provided at the contact point between the first surface of the substrate and the annular structural member, or at the contact point between the end face of the frame facing the substrate and the annular structural member; alternatively, flexible support members can be provided at both the contact points between the substrate and the annular structural member and between the frame and the annular structural member. The flexible support member can reduce hard contact between the two structures and prevent deformation of the substrate under stress from affecting the components on the substrate. When a flexible support member is provided between the annular structural member and the frame of the housing, the flexible support member can be located between the boss and the end face of the frame facing the substrate. Furthermore, when the substrate and the frame are connected, fixed, and clamp the annular structural member, the flexible support member can deform to improve the tightness of the fit between the contacting structures and enhance the sealing effect. The flexible support member can be made of foam, rubber, or silicone.
[0012] In one possible implementation, a gap exists between the annular structural component and the outer peripheral surface of any electrolytic capacitor. This gap ensures that a portion of the impact force is dissipated in advance when the electrolytic capacitor is broken down by instantaneous overvoltage, thus improving the reliability of the protection.
[0013] In one possible implementation, the ring-shaped structural component can be made of any one of nylon, polypropylene, or polyphenylene sulfide, and can be manufactured using injection molding. In practical applications, even if these ring-shaped structural components are splashed with electrolyte from an electrolytic capacitor, they will not become charged and thus will not affect the function or safety of other devices.
[0014] Secondly, this application provides a charging pile, which includes at least one charging gun and at least one power conversion device provided in the first aspect. The power conversion device is used to convert the input electrical energy into power, and the at least one charging gun is used to output the converted electrical energy to an electric vehicle. The electrolytic capacitor of the power conversion device can prevent electrolyte leakage by splashing when it is broken down by instantaneous overvoltage, thus preventing secondary failures and improving the safety of the charging pile.
[0015] In one possible implementation, at least one power conversion device in the charging pile includes multiple AC-DC power conversion devices, and the charging pile also includes multiple DC-DC power conversion devices, a DC bus, and a power distribution device. The output terminals of the multiple AC-DC power conversion devices are connected to the DC bus, the input terminals of the multiple DC-DC power conversion devices are connected to the DC bus, and the output terminals of the multiple DC-DC power conversion devices are connected to at least one charging gun through the power distribution device. The charging pile with this power conversion device can prevent electrolyte leakage when the electrolytic capacitor is broken down by instantaneous overvoltage, thus preventing other power devices in the system from being affected by the electrolyte and experiencing arcing, sparking, or other phenomena, thereby improving the safety of the bus capacitor. Attached Figure Description
[0016] Figure 1a This is a schematic diagram of the structure of a charging pile provided in an embodiment of this application;
[0017] Figure 1b This is a circuit topology diagram of a power conversion device provided in an embodiment of this application;
[0018] Figure 1c This is a schematic diagram of the structure of a charging pile provided in an embodiment of this application;
[0019] Figure 1d This is a circuit topology diagram of a power conversion device provided in an embodiment of this application;
[0020] Figure 2a This is a schematic diagram of the structure of a power conversion device provided in an embodiment of this application;
[0021] Figure 2b An exploded view of a power conversion device provided in an embodiment of this application;
[0022] Figure 3a This is a schematic diagram of the structure of a ring-shaped component in a power conversion device provided in an embodiment of this application;
[0023] Figure 3b This is a schematic diagram of the structure of a ring-shaped structural component and its fit with a housing in a power conversion device according to an embodiment of this application;
[0024] Figure 3c This is a cross-sectional structural schematic diagram of a power conversion device provided in an embodiment of this application;
[0025] Figure 4a This is a cross-sectional structural schematic diagram of a power conversion device provided in an embodiment of this application;
[0026] Figure 4b This is a cross-sectional structural schematic diagram of a power conversion device provided in an embodiment of this application;
[0027] Figure 4c This is a cross-sectional structural schematic diagram of a power conversion device provided in an embodiment of this application;
[0028] Figure 5 This is a schematic diagram of the structure of a power conversion device in which a ring structure and a flexible support are combined, provided in an embodiment of this application.
[0029] Figure 6 This is a schematic diagram illustrating the assembly principle of a power conversion device provided in an embodiment of this application.
[0030] Figure label:
[0031] 100-Charging pile; 101-Power conversion device; 102-Power distribution module; 103-Charging gun; 104-DC to DC module; 105-DC bus;
[0032] 1111 - Inductor; 1112 - Power device; 11121 - First power device; 11122 - Second power device; 1113 - Capacitor;
[0033] 11-House; 111-Bottom shell; 112-Frame; 12-Substrate; 13-Electrolytic capacitor; 131-Pin; 14-Ring structure; 141-Ring baffle; 142-Ring retaining ring; 143-Boss; 144-Recess; 15-Screw; 16-Flexible support. Detailed Implementation
[0034] As the power density of power supply boards continues to increase, the distance between electronic components is decreasing, and some components are even stacked. Electrolytic capacitors are widely used on various circuit boards, and these capacitors contain a large amount of electrolyte. When an electrolytic capacitor is broken down by a momentary overvoltage, it will cause electrolyte splashing. Taking a high-power rectifier module as an example, a single point of failure in the module can easily cause the electrolytic capacitor to break down, and the resulting electrolyte splashing can contaminate the board and even cause secondary failures. Since the breakdown point of an electrolytic capacitor is often random, the technical solution of using explosion-proof valves to control the position and direction of capacitor splashing has limited effectiveness, and the technical solution of adding adhesive at the capacitor feet to prevent electrolyte outflow has also yielded minimal results.
[0035] Based on this, the present application provides a power conversion device and a charging pile. The power conversion device can provide good sealing protection for the electrolyte of the electrolytic capacitor, preventing electrolyte splashing after the electrolytic capacitor breaks down, and increasing the safety of the device.
[0036] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.
[0037] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to also include expressions such as “one or more” unless the context clearly indicates otherwise.
[0038] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.
[0039] Figure 1a This is a schematic diagram of the structure of a charging pile 100 provided in an embodiment of this application. Figure 1a As shown, the charging pile 100 includes at least one power conversion device 101, at least one direct current-to-direct current (DC-DC) module 104, a power distribution module 102, and at least one charging gun 103. The at least one power conversion device 101 includes multiple alternating current-to-direct current (AC-DC) power conversion devices. Each AC-to-DC power conversion device includes an AC-to-DC power conversion circuit that converts AC power into DC power and outputs it to the DC-to-DC module 104 via a DC bus 105. Exemplarily, the outputs of the multiple power conversion devices 101 are combined and connected to the multiple DC-to-DC modules 104 via the DC bus 105. The outputs of the multiple DC-to-DC modules 104 are respectively connected to the power distribution module 102, which supplies power to the multiple charging guns 103. In the charging pile 100 provided in this application embodiment, the DC-to-DC module 104 can be simply referred to as a DC-DC power conversion device or a DC-DC module, and the AC-to-DC power conversion device can be simply referred to as an AC-DC power conversion device.
[0040] by Figure 1b Taking the circuit topology of an AC-to-DC power conversion device 101 as an example, the power conversion device 101 includes an inductor 1111, a power device 1112, and a capacitor 1113. The capacitor 1113 and the power device 1112 are connected to form an AC-to-DC power conversion circuit, and the inductor 1111 is connected in series in this circuit. The capacitor 1113 is connected in parallel to the output terminal of the power conversion circuit for connecting to the bus; the capacitor 1113 is generally also called the bus capacitor. The power device 1112 can realize the switching function in the circuit.
[0041] Figure 1cThis is a schematic diagram of another charging pile 100 provided in an embodiment of this application. Figure 1c As shown, the charging pile 100 includes at least one power conversion device 101, a power distribution module 102, and at least one charging gun 103. The power conversion device 101 includes an AC to DC power conversion circuit and a DC to DC power conversion circuit, which can convert AC power from AC power supply to DC power and supply power to the plurality of charging guns 103 through the power distribution module 102.
[0042] by Figure 1d Taking the circuit topology of an integrated AC-to-DC and DC-to-DC power conversion device 101 as an example, the power conversion device 101 includes an inductor 1111, a first power device 11121, a capacitor 1113, and a second power device 11122. The capacitor 1113 is connected to the first power device 11121 to form an AC-to-DC power conversion circuit, and the inductor 1111 is connected in series in this circuit. The capacitor 1113 is connected to the second power device 11122 to form a DC-to-DC power conversion circuit. This power conversion device 101 integrates the AC-to-DC power conversion circuit and the DC-to-DC power conversion circuit into one module, with the capacitor 1113 located between the two circuits.
[0043] Figure 2a This application provides a structure for a power conversion device 101 according to an embodiment of the present application. Figure 2b This is an exploded view of the power conversion device 101. An embodiment of this application provides a power conversion device 101 including a housing 11, a substrate 12, an annular structural member 14, and at least one electrolytic capacitor 13. Power devices and other structures of the power conversion device 101 are not shown here. It should be understood that the at least one electrolytic capacitor 13 can be used as… Figure 1b and Figure 1d The capacitor 1113 shown is at least one electrolytic capacitor 13, which can be connected to the aforementioned power device via the substrate 12 to form a power conversion circuit. Depending on the specific implementation of the power conversion device 101, the at least one electrolytic capacitor 13 can be connected to the power device via the substrate 12 to form, as shown... Figure 1b The AC-to-DC power conversion circuit shown, or the at least one electrolytic capacitor 13 can be connected to the power device via the substrate 12 to form a circuit as shown. Figure 1d The integrated AC-to-DC and DC-to-DC power conversion circuits shown are illustrated. Of course, when the power conversion device 101 includes other forms of power conversion circuits, the circuit connection of the at least one electrolytic capacitor 13 with the power device can be adaptively adjusted according to requirements.
[0044] Please continue to refer to Figure 2aAs shown, the housing 11 includes a bottom shell 111 and a frame 112. The frame 112 is fixed to the bottom shell 111 in a manner that circumferentially surrounds the at least one electrolytic capacitor 13. A plurality of electrolytic capacitors 13 are exemplarily shown here, which are sealed between the substrate 12 and the housing 11. Figure 2a Only the pins 131 of each electrolytic capacitor 13 exposed on the side of the substrate 12 facing away from the housing 11 are shown. Each electrolytic capacitor 13 has two leads. An annular structural member 14 is fixed to the substrate 12. It should be understood that the bottom shell 111 and the frame 112 are part of the housing 11 of the power conversion device 101. In some embodiments, they have an integral structure and can be formed using integral manufacturing processes such as casting and stamping. In practical applications, the power conversion device 101 also includes other components. The bottom shell 111 and substrate 12 of the housing 11 have larger dimensions to accommodate the components included in the power conversion device 101, while the frame 112 is... Figure 2b The structure shown is adapted to at least one electrolytic capacitor 13. It can be considered that the structure of the bottom shell 111 and the substrate 12 is adapted to the structure of the power conversion module 111, while the structure of the frame 112 is adapted to the structure of the at least one electrolytic capacitor 13.
[0045] For ease of understanding, Figure 2a Using the structure of the frame 112 shown as a reference, a three-dimensional coordinate system with two perpendicular axes is established. For example, the X direction is the length direction of the frame 112, the Y direction is the width direction of the frame 112, and the Z direction is the height direction of the frame 112. The substrate 12 is connected and fixed to the frame 112 along the Z direction, which can also be considered as the thickness direction of the substrate 12.
[0046] like Figure 2bAs shown, the bottom shell 111, together with the frame 112, forms a receiving space R capable of accommodating the plurality of electrolytic capacitors 13. The receiving space R can be filled with potting compound G to a certain height. The inner wall of the frame 112 is adapted to the circumferential shape of the plurality of electrolytic capacitors 13. The substrate 12 has opposing first surfaces a1 and second surfaces a2. The feet of each electrolytic capacitor 13 are fixed to the first surface a1 of the substrate 12, and the leads 131 of the feet of the electrolytic capacitor 13 can pass through the substrate 12 and protrude from the second surface a2 of the substrate 12. Along the Z direction, each electrolytic capacitor 13 protrudes from the first surface a1. Here, the electrolytic capacitor 13 is shown in a cylindrical structure, and the Z direction can be considered as the axial direction of the electrolytic capacitor 13 or the height direction of the electrolytic capacitor 13. Along the direction perpendicular to Z, the plurality of electrolytic capacitors 13 are arranged in an array, which can make full use of space and help reduce the size of the power conversion device 101. The substrate 12 can be fixed to the frame 112 with its first surface a1 facing the housing 11, thereby housing multiple electrolytic capacitors 13 within the receiving space R. The end of the electrolytic capacitor 13 facing away from the substrate 12 can be immersed in and sealed by potting compound G; this end of the electrolytic capacitor 13 facing away from the substrate 12 is also the top of the electrolytic capacitor 13. The annular structure 14 is annular in shape and has a through hole K extending along the direction from the substrate 12 toward the base 111 of the housing 11. The inner and outer walls of the through hole K are the inner and outer surfaces of the annular structure 14, thus forming the annular structure 14. The end of the annular structure 14 facing the substrate 12 can be fixed between the substrates 12, and the end of the annular structure 14 facing away from the substrate 12 can extend into the receiving space R and be fixed to the potting compound G. The portion of the annular structural member 14 extending into the receiving space R acts as a barrier between the inner wall of the frame 112 and the outer peripheral surface of the electrolytic capacitor 13, preventing electrolyte from spraying out and contacting the frame 112 in the event of electrolytic capacitor 13 breakdown, thus preventing electrical connection risks. The end of the annular structural member 14 facing away from the substrate 12 is also the end of the annular structural member 14 facing the bottom shell 111. The annular structural member 14, housed within the receiving space R, can surround the circumference of the plurality of electrolytic capacitors 13, thereby providing circumferential protection for the plurality of electrolytic capacitors 13. The circumferential direction of the electrolytic capacitors 13 is the surrounding direction perpendicular to the Z-direction.
[0047] In the power conversion device 101 provided in this application embodiment, one end of the annular structural member 14 facing the bottom shell 111 extends into the receiving space R and is connected and fixed to the potting compound G. It surrounds the multiple electrolytic capacitors 13 circumferentially, and in conjunction with the substrate 12, provides sealing protection for the circumference and top of the multiple electrolytic capacitors 13. When any electrolytic capacitor 13 experiences overvoltage breakdown, the top of the electrolytic capacitor 13 is prevented from splashing out due to the sealing of the potting compound G, and the circumferential direction of the electrolytic capacitor 13 is prevented from splashing out from the circumferential side and contacting the housing 11 due to the sealing of the annular structural member 14. This prevents the electrolyte of the electrolytic capacitor 13 from leaking out of the enclosure 112, suppresses fault propagation, and prevents the electrolyte overflow of the electrolytic capacitor 13 from posing a safety risk to other components of the power conversion device. This protective structure has higher reliability and is applicable not only to the case of slow leakage of electrolyte in the electrolytic capacitor 13, but also to the protection against electrolyte splashing during instantaneous overvoltage breakdown of the electrolytic capacitor 13.
[0048] In some embodiments, the annular structure 14 does not contact the outer peripheral surface of any one of the electrolytic capacitors 13; that is, a gap exists between the annular structure 14 and the outer peripheral surface of any one of the electrolytic capacitors 13. This gap ensures that a portion of the impact force is dissipated in advance when the electrolytic capacitor 13 is broken down by instantaneous overvoltage, thus improving the reliability of the protection. Regarding the structure of the electrolytic capacitor 13, in locations where the risk of instantaneous overvoltage of the electrolytic capacitor 13 is relatively low, the distance between the electrolytic capacitor 13 and the annular structure 14 can be increased.
[0049] Figure 3a A schematic diagram of the ring-shaped structural component 14 is shown. Figure 3aAs shown, the annular structure 14 is an integral annular structure, and its inner wall is the through hole K. Exemplarily, along the radial direction of the electrolytic capacitor 13, one end of the annular structure 14 facing the substrate 12 extends radially between the substrate 12 and the end face of the frame 112 facing the substrate 12. With the radial direction of the electrolytic capacitor 13 as a reference, the end of the annular structure 14 facing the substrate 12 is equivalent to a circumferential protrusion beyond the end of the annular structure 14 facing the bottom shell 111. Along the radial direction of the electrolytic capacitor 13, the length of the end of the annular structure 14 facing the substrate 12 is greater than the length of the end of the annular structure 14 facing the bottom shell 111. That is, with any radial direction of the electrolytic capacitor 13 as a reference, the length of the end of the annular structure 14 facing the substrate 12 is always greater than the length of the end of the annular structure 14 facing the bottom shell 111. For ease of understanding, the annular structure 14 can be divided into two parts: an annular baffle 141 and an annular retaining ring 142. The annular retaining ring 142 is the structure of the end of the annular structural member 14 facing the substrate 12, and the annular baffle 141 is the structure of the end of the annular structural member 14 facing the bottom shell 111. The annular baffle 141 and the annular retaining ring 142 are different parts of the annular structural member 14. Along the radial direction of the electrolytic capacitor 13, the annular retaining ring 142 protrudes from the outer peripheral surface of the annular baffle 141, so that the annular retaining ring 142 can extend between the substrate 12 and the frame 112 and be fixed to the substrate 12.
[0050] Please continue to refer to Figure 3a An annular baffle 141 extends into the receiving space R formed by the frame 112 and the bottom shell 111 and surrounds multiple electrolytic capacitors 13 circumferentially. The outer wall shape of the annular baffle 141 is adapted to the shape of the receiving space R, and the inner wall shape of the annular baffle 141 is adapted to the shape of the multiple electrolytic capacitors 13. In this structure, the surface of the annular retaining ring 142 facing the substrate 12 can be pressed and fixed to the substrate 12. The contact surface between the annular retaining ring 142 and the substrate 12 is annular, surrounding the multiple electrolytic capacitors 13. The annular retaining ring 142 and the substrate 12 have a larger contact area, resulting in a better connection and sealing effect. To enhance the structural strength at the connection between the annular retaining ring 142 and the annular baffle 141, multiple reinforcing ribs B are provided at the corners of the outer peripheral surfaces of the annular retaining ring 142 and the annular baffle 141. The multiple reinforcing ribs B are distributed circumferentially along the annular structure 14.
[0051] For example, please continue to refer to Figure 3aAs shown, one end of the annular structural member 14 facing the substrate 12 faces the surface of the frame 112, which is also the surface of the annular retaining ring 142 facing the frame 112. Exemplarily, this surface includes a plurality of protrusions 143, which are spaced apart circumferentially along the annular structural member 14. When the annular structural member 14 is fixed between the frame 112 and the substrate 12, the surface of the annular retaining ring 142 facing away from the annular baffle 141 abuts against the surface of the substrate 12 facing the frame 112, and the surface of each protrusion 143 facing away from the annular retaining ring 142 abuts against the surface of the frame 112 facing the substrate 12. The annular structural member 14 is effectively clamped and fixed between the substrate 12 and the frame 112, strengthening the connection and fixation between the annular structural member 14, the frame 112, and the substrate 12. Along the wall thickness direction of the annular structural member 14, each protrusion 143 protrudes beyond the outer circumferential surface of the annular baffle 141 but not beyond the edge of the annular retaining ring 142.
[0052] For example, the annular structural component 14 is an injection-molded part, and the material of the annular structural component 14 can be any one of nylon, polypropylene, or polyphenylene sulfide, all of which are insulating materials. In practical applications, even if the electrolytic capacitor 13 breaks down, causing electrolyte to splash onto the annular structural component 14, the annular structural component 14 will not be electrified, and therefore there will be no risk of affecting the function of other devices or causing safety hazards. Multiple bosses 143 can also be integrally formed between the annular baffle 141 and the annular retaining ring 142 during the injection molding of the annular structural component 14.
[0053] To ensure balanced stress distribution in the injection-molded annular structural component 14, recesses 144 corresponding to bosses 143 are formed on the inner wall of the annular structural component 14 along its wall thickness direction. Each boss 143 corresponds to a recess 144. The shape of the boss 143 protruding from the outer wall of the annular structural component 14 matches the shape of the recess 144 on the inner wall, ensuring that the wall thickness of the annular structural component 14 remains close to that of other structural components at the location of the boss 143. This prevents excessive changes in the wall thickness of the annular structural component 14 from causing uneven stress distribution and ensures the structural strength of the annular structural component 14.
[0054] In some embodiments, the substrate 12 and the frame 112 are connected by screws or other connectors. The annular baffle 141 of the annular structural member 14, housed between the substrate 12 and the frame 112, has clearance notches Q. The number of clearance notches Q is the same as the number of connectors used between the substrate 12 and the frame 112, and each clearance notch Q allows one connector to pass through. Generally, the edge of the substrate 12 is connected and fixed to the frame 112 by a plurality of connectors, which are spaced apart circumferentially along the frame 112. Correspondingly, the plurality of clearance notches Q are spaced apart circumferentially along the annular structural member 14. Along the circumference of the annular structural member 14, the clearance notches Q and the bosses 143 are spaced apart, such that there is no structural overlap or interference between the clearance notches Q and the bosses 143, so as not to affect the connection and fixation between the annular structural member 14, the frame 112, and the substrate 12.
[0055] Figure 3b for Figure 3a The diagram shows the structural arrangement of the annular structural member 14 and the housing 11. Figure 3b As shown, the annular baffle 141 of the annular structural member 14 extends into the receiving space R formed by the frame 112 and the bottom shell 111 along the height direction of the frame 112. The annular retaining ring 142 protrudes from the end face of the frame 112 away from the bottom shell 111. The boss 143 of the annular structural member 14 can abut against the end face of the frame 112 away from the bottom shell 111.
[0056] Figure 3c This is a partial structural cross-sectional schematic diagram of the power conversion device 101 provided in an embodiment of this application. Figure 3cAs shown, the feet of multiple electrolytic capacitors 13 are fixed to the substrate 12, and the leads 131 protrude from the surface of the substrate 12 away from the housing 11. The substrate 12 is exemplarily fixed to the frame 112 by screws 15 or other connectors. The top of the electrolytic capacitors 13, away from the substrate 12, is immersed in the potting compound G in the receiving space R. The top end face of the electrolytic capacitors 13 is below the liquid surface of the potting compound G, and the top of the electrolytic capacitors 13 maintains a certain distance from the bottom shell 111 of the housing 11. The potting compound G can seal the top of the electrolytic capacitors 13. The annular retaining ring 142 of the annular structure 14 is located between the substrate 12 and the frame 112 and abuts against the substrate 12. The boss 143 of the annular structure 14 is located between the substrate 12 and the frame 112 and abuts against the frame 112. The clearance notch Q of the annular structure 14 avoids the screws 15, so that the annular structure 14 can be clamped and fixed by the connection and fixation between the substrate 12 and the frame 112. An annular baffle 141 extends along the height of the frame 112 into the receiving space R formed by the frame 112 and the bottom shell 111. The end of the annular baffle 141 furthest from the substrate 12 is immersed in the potting compound G within the receiving space R. The end face of the annular baffle 141 facing the bottom shell 111 is below the liquid surface of the potting compound G. The annular baffle 141 can seal the circumference of multiple electrolytic capacitors 13. It should be noted that the potting compound G within the receiving space R needs to have a certain height, so that at least one-third of the electrolytic capacitor 13 can be submerged in the potting compound G. The potting compound G can partially encapsulate the electrolytic capacitor 13 to dissipate heat.
[0057] In the above embodiments, the substrate 12, the annular structure 14 and the housing 11 can be designed with an interference fit, so that the structure of the annular structure 14 located between the substrate 12 and the frame 112 of the housing 11 can be clamped and fixed to achieve a good seal.
[0058] The power conversion device 101 provided in this application embodiment may also integrate other components on the substrate 12. If the substrate 12 warps in a partial area under stress, it may affect the functionality of this component. To reduce the risk of warping of the substrate 12 under stress, it is possible to... Figure 4a As shown, a flexible support member 16 is provided at the contact point between the substrate 12 and the annular structure 14, or as shown in the figure. Figure 4b As shown, a flexible support is provided at the abutment of the frame 112 and the annular structural member 14, or as shown in the figure. Figure 4c Flexible support members 16 are provided at the contact points between the substrate 12 and the annular structure 14, and at the contact points between the frame 112 and the annular structure 14, respectively. The flexible support members 16 can reduce hard contact between the two structures and prevent the substrate 12 from being deformed by force, which would affect the safety and functionality of the components on the substrate 12.
[0059] As an example, such as Figure 5As shown, taking the structure of the annular structure 14 as an example, each protrusion 143 is provided with a flexible support 16 on the side facing the frame 112. The shape of the flexible support 16 is adapted to the shape of the end face of each protrusion 143 facing the frame 112. The flexible support 16 can be made of flexible materials such as foam, rubber, or silicone. When the annular structure 14 is clamped and fixed by the base plate 12 and the frame 112 of the housing 11, the flexible support 16 is squeezed and fixed between the protrusion 143 of the annular structure 14 and the frame 112. The flexible support 16 deforms under force and fits tightly between the protrusion 143 and the frame 112, improving the sealing effect and preventing the electrolyte of the electrolytic capacitor 13 from flowing out of the housing 11.
[0060] When assembling the power conversion device 101 provided in this application embodiment, such as Figure 6 As shown, the housing 11 is placed with the bottom shell 111 facing downwards. The receiving space R enclosed by the frame 112 and the bottom shell 111 is indicated by a dashed line, and the receiving space R contains potting compound G. Along the Z direction, the height H1 of the receiving space R enclosed by the frame 112 and the bottom shell 111 is the sum of the height H12 of the potting compound G and the distance H11 between the end of the potting compound G and the end of the frame 112 away from the bottom shell 111. Along the direction perpendicular to Z, the receiving space R has a radial dimension L1. The annular structural member 14 is assembled to the housing 11 along the Z direction. The annular retaining ring 142 of the annular structural member 14 protrudes from the end face of the frame 112 away from the bottom shell 111, and the annular baffle 141 is used to extend into the receiving space R enclosed by the frame 112 and the bottom shell 111 and immerse the potting compound G to achieve a sealed connection between the annular structural member 14 and the potting compound G. A flexible support member 16 is provided on the surface of the boss 143 facing the frame 112. Along the Z-direction, the distance H21 between the end face of the annular baffle 141 of the annular structural member 14 away from the annular baffle 141 and the end face of the flexible support member 16 away from the annular retaining ring 142 is less than the height H1 of the accommodating space R, and greater than the distance H11 between the potting compound G and the end of the frame 112 away from the bottom shell 111. When the annular structural member 14 is assembled into the housing 11, along the Z-direction, the height of the end face of the annular structural member 14 protruding from the frame 112 away from the bottom shell 111 is greater than H22, which is the height of the boss 143. The height of the annular structural member 14 extending into the accommodating space R, i.e., H21, is the distance H21 between the end face of the annular baffle 141 away from the annular baffle 141 and the end face of the flexible support member 16 away from the annular retaining ring 142, so that the annular baffle 141 can be sealed with the potting compound G. Along the X direction, the radial dimension of the annular baffle 141 of the annular structure 14 can be less than or equal to the radial dimension L1 of the accommodating space R, facilitating the insertion of the annular baffle 141 into the accommodating space R. The radial dimension L2 of the through hole K of the annular structure 14 along the direction perpendicular to Z is less than the radial dimension of the annular baffle 141. The direction perpendicular to Z can be considered as being along the radial direction of the electrolytic capacitor 13.
[0061] Please continue to refer to Figure 6 As shown, the leads of multiple electrolytic capacitors 13 are fixed to the first surface a1 of the substrate 12, and the leads 131 of each electrolytic capacitor 13 extend through the substrate 12 and protrude from the second surface a2 of the substrate 12. Along the Z-direction, the height H3 of each electrolytic capacitor 13 is less than the height H1 of the housing space R of the housing 11 and greater than the distance H11 between the potting compound G and the end of the frame 112 furthest from the bottom shell 111. When the substrate 12 is assembled onto the housing 11, the top of each electrolytic capacitor 13 furthest from the substrate 12 can be immersed in the potting compound G to achieve a seal. The annular baffle 141 of the annular structure 14 surrounds multiple electrolytic capacitors 13 along a direction perpendicular to Z. The radial dimension L3 of the multiple electrolytic capacitors 13 is smaller than the radial dimension L2 of the through hole K of the annular structure 14, so that the outer peripheral surface of any electrolytic capacitor 13 does not contact the inner wall of the through hole K of the annular structure 14 and maintains a certain gap, so as to dissipate part of the impact force in advance when the electrolytic capacitor 13 is broken down by instantaneous overvoltage, thereby increasing the reliability of protection.
[0062] After the power conversion device 101 is assembled, the edge of the annular structure 14 does not protrude beyond the edge of the frame 112 along the direction perpendicular to Z, and the annular structure 14 will not occupy more space.
[0063] In summary, the power conversion device 101 provided in this application embodiment, through the cooperation of the annular structural member 14 with the substrate 12 and the housing 11, can seal the top and circumference of the electrolytic capacitor 13. When the electrolytic capacitor 13 experiences instantaneous overvoltage and electrolyte splashing occurs, the electrolyte can be sealed within the containment space R formed by the frame 112 and the bottom shell 111, preventing electrolyte from leaking out of the housing 11 and contaminating other components, thus suppressing the spread of faults and potential safety hazards. The substrate 12 and housing 11 are fixed with the top of the electrolytic capacitor 13 facing downwards, so electrolyte splashing caused by instantaneous overvoltage of the electrolytic capacitor 13 will not contaminate the substrate 12. Charging piles equipped with this power conversion device 101, because the power conversion device 101 can prevent electrolyte leakage during electrolytic capacitor overvoltage, can prevent other power devices in the system from being affected by the electrolyte and experiencing arcing, sparking, or other phenomena, thus improving the safety of the bus capacitor.
[0064] It should be understood that the protection provided by the power conversion device 101 in this application embodiment for the electrolytic capacitor 13 can also be applied to other electrolyte splash protection for electrolytic capacitors 13. For example, DC-DC power modules or other device modules with electrolytic capacitors can have a ring-shaped structure similar to the above-described structure added to the module structure, along with potting compound, to provide splash protection for the circumference and top of the electrolytic capacitor. The power conversion device 101 provided in this application embodiment can also be applied to most charging or power supply devices with power modules, including but not limited to onboard chargers (OBC), uninterruptible power supplies (UPS) for data center energy, and power converters for energy storage systems. Taking charging devices as an example, the power module included in the charging device can include the power conversion device 101 provided in the above embodiment, and the charging device with the power conversion device 101 has higher safety.
[0065] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A power conversion device, characterized in that, The power conversion device includes a housing, a substrate, a ring structure, a power device, and at least one electrolytic capacitor. The power device and the at least one electrolytic capacitor are connected through the substrate to form a power conversion circuit. The housing includes a bottom shell and a surrounding frame, the surrounding frame and the bottom shell together enclosing an accommodating space; The substrate has a first surface and a second surface opposite to each other, and the lead of each electrolytic capacitor is fixed to the first surface of the substrate; The first surface of the substrate faces the bottom shell and is fixed to the frame so that the electrolytic capacitor is accommodated in the accommodating space, and potting compound is filled between the at least one electrolytic capacitor and the bottom shell; The annular structural member is circumferentially surrounding the at least one electrolytic capacitor. One end of the annular structural member facing the substrate is fixed to the substrate, and the other end of the annular structural member facing the bottom shell extends into the receiving space of the housing and is fixed to the potting compound.
2. The power conversion device as described in claim 1, characterized in that, The annular structure extends radially from one end toward the substrate to between the substrate and the end face of the frame toward the substrate, and the length of the end of the annular structure toward the substrate is greater than the length of the end of the annular structure toward the bottom shell.
3. The power conversion device as described in claim 2, characterized in that, The annular structure includes a surface facing the frame at one end facing the substrate. The surface facing the frame includes a plurality of protrusions arranged circumferentially along the annular structure. Each of the protrusions abuts against the surface of the frame facing the substrate.
4. The power conversion device as described in claim 3, characterized in that, The substrate and the end face of the frame facing the substrate are connected by a plurality of connectors. The end of the annular structure facing the substrate includes a clearance notch, and each clearance notch is used to pass through one of the connectors. Along the circumference of the annular structural member, the clearance notch and the boss are arranged at intervals.
5. The power conversion device as described in claim 4, characterized in that, The inner wall of the annular structure has a plurality of recesses, and each recess corresponds to a protrusion along the wall thickness direction of the annular structure.
6. The power conversion device as described in claim 2, characterized in that, At least one of the substrates and the frame is provided with a flexible support at the point of contact with the annular structure.
7. The power conversion device as claimed in claim 1, characterized in that, The ring-shaped structural component is made of any one of nylon, polypropylene, or polyphenylene sulfide.
8. The power conversion device according to any one of claims 1-7, characterized in that, There is a gap between the annular structural component and the outer peripheral surface of any one of the electrolytic capacitors.
9. A charging pile, characterized in that, The charging pile includes at least one charging gun and at least one power conversion device as described in any one of claims 1-8, wherein the power conversion device is used to convert the input electrical energy into power, and the at least one charging gun is used to output the converted electrical energy to an electric vehicle.
10. The charging pile according to claim 9, characterized in that, The at least one power conversion device includes multiple AC-DC power conversion devices, and the charging pile also includes multiple DC-DC power conversion devices, a DC bus, and a power distribution device; The output terminals of the plurality of AC-DC power conversion devices are connected to the input terminals of the plurality of DC-DC power conversion devices via the DC bus, and the output terminals of the plurality of DC-DC power conversion devices are connected to the at least one charging gun via the power distribution device.