Power conversion device

Abstract

The embodiment of the application provides a kind of power conversion equipment, it relates to energy technical field.The power conversion equipment includes equipment shell, equipment cover and power conversion circuit, equipment shell and equipment cover are enclosed for accommodating the space of power conversion circuit;Power conversion equipment further includes fastener and restraint, fastener connects equipment shell and equipment cover, fastener has through hole, through hole is along the arrangement direction of equipment shell and equipment cover and penetrates fastener;Restraint includes connecting portion and two abutting portions, connecting portion is threaded in through hole, the length of connecting portion is greater than the length of through hole, two abutting portions are respectively fixed to different ends of connecting portion and are located outside through hole, and the size of each abutting portion can limit itself through through hole.By the above technical scheme, the constraint between the equipment shell and the equipment cover of the power conversion equipment is strengthened, the possibility that the equipment cover is ejected due to explosion impact after the failure of the power conversion equipment is reduced, and the safety and explosion-proof performance of the power conversion equipment are improved.

Description

Technical Field

[0001] This application relates to the field of energy technology, and in particular to a power conversion device. Background Technology

[0002] During operation, power conversion equipment (such as inverters and energy storage converters) may experience internal component failures under extreme conditions such as overvoltage and overtemperature, potentially generating flammable gases such as propane and methane. If these flammable gases ignite and explode inside the power conversion equipment, the internal pressure will increase, causing screws on the equipment to break and potentially resulting in the equipment cover being ejected by the explosive impact. This could severely compromise the safety of surrounding equipment and personnel. Utility Model Content

[0003] This application provides a power conversion device that strengthens the constraint between the device housing and the device cover, reduces the possibility of the device cover flying off due to an explosion impact after a power conversion device failure, and improves the safety and explosion-proof performance of the power conversion device.

[0004] To achieve the above objectives, this application adopts the following technical solution:

[0005] This application provides a power conversion device, which includes a housing, a cover, and a power conversion circuit. The housing and cover enclose a space for housing the power conversion circuit, which converts direct current (DC) from a photovoltaic module or a storage battery into alternating current (AC). The power conversion device also includes fasteners and constraint members. The fasteners connect the housing and cover and have through holes that extend through the fasteners along the arrangement direction of the housing and cover. The constraint members include a connecting portion and two abutting portions. The connecting portion passes through the through hole and has a length greater than the length of the through hole. The two abutting portions are fixed to different ends of the connecting portion and are both located outside the through hole. The size of each abutting portion is sufficient to restrict itself from passing through the through hole.

[0006] Direct current (DC) from photovoltaic modules or energy storage batteries can be converted into alternating current (AC) by the power conversion circuit in the power conversion equipment. The equipment housing and cover constitute the protective shell (or outer casing) of the power conversion equipment, and the space enclosed by the housing and cover houses the power conversion circuit. In the event of a malfunction in the power conversion equipment, an internal combustion and explosion may occur. The pressure inside the space enclosed by the housing and cover increases, and the cover is subjected to the explosive impact. The fasteners break, absorbing some of the explosive energy. Part of the broken fastener remains on the housing, while the other part is ejected with the cover.

[0007] After the equipment cover, carrying a portion of the fastener, flies out, the two abutting parts of the constraint member abut against the ends of the fastener. Therefore, under the constraint of the constraint member, the equipment cover will not fly out indefinitely; its flight distance will be limited to around the equipment shell. For example, if the fastener breaks into a first part and a second part, with the first part located on the equipment shell and the second part flying out with the equipment cover, one abutting part abuts against the first part, and the other abutting part abuts against the second part. The connecting part of the constraint member holds the two abutting parts, thus holding the equipment shell and the equipment cover together, thereby constraining the distance between them. Furthermore, the length of the connecting part of the constraint member is greater than the length of the fastener, allowing the equipment cover and the equipment shell to separate at a certain distance and form a pressure relief gap for timely depressurization.

[0008] The restraints between the equipment housing and cover are strengthened by the constraint components, reducing the likelihood of the cover being ejected due to an explosive impact after a power conversion device failure. This also reduces the possibility of an excessively large opening between the cover and housing (where the cover would fly out further without restraints). Furthermore, the cover's obstruction reduces the likelihood of internal debris (e.g., fragments of electronic components) being ejected, improving the safety and explosion-proof performance of the power conversion device. In addition, this application modifies the fasteners, reducing the extent of alterations to the equipment housing and cover, lowering the difficulty of modifying the power conversion device, and reducing production and modification costs.

[0009] In one optional embodiment, the fastener includes a shank and a head, the shank having external threads, the head being fixed to one end of the shank and protruding radially toward one side of the shank, a through hole penetrating the head and the shank; the shank passing through the equipment housing and threadedly connected to the equipment cover, the head being located on the side of the equipment housing opposite to the equipment cover and abutting against the equipment housing; or, the shank passing through the equipment cover and threadedly connected to the equipment housing, the head being located on the side of the equipment cover opposite to the equipment housing and abutting against the equipment cover.

[0010] Fasteners secure the equipment housing and cover. For example, when installing a fastener, the shank of the fastener is inserted into and passes through the housing from one side. Rotating the fastener creates a threaded connection between the shank and the cover, causing the head of the fastener to abut against the housing, thus securing the cover to the housing. To remove the fastener, it is rotated in the opposite direction from one side of the housing and then pulled out. In this case, the fastener can be installed without passing through the cover. After the power conversion equipment is installed in a designated location (e.g., on a support rod or wall), the cover is positioned away from the installation location of the power conversion equipment (e.g., the cover is directly visible to personnel). The cover conceals the fastener, making the power conversion equipment more aesthetically pleasing and protecting the fastener, reducing the possibility of it being arbitrarily rotated by personnel (e.g., non-maintenance personnel).

[0011] For example, when installing fasteners, the shank of the fastener is inserted from one side of the equipment cover and passes through it, connecting the shank to the threaded connection of the cover to the housing, with the head of the fastener abutting against the cover, thus securing the cover to the housing. To remove the fastener, it is rotated in the opposite direction from one side of the cover and then pulled out. In this configuration, after the power conversion equipment is installed in the designated location, the equipment cover is positioned away from the installation location, allowing maintenance personnel to directly see the cover. Maintenance personnel can easily tighten or loosen the fasteners while standing on one side of the cover, facilitating maintenance of the power conversion equipment.

[0012] In one optional embodiment, a first orifice is formed on the surface of the rod away from the head, and a second orifice is formed on the surface of the head away from the rod. The two abutting portions include a first abutting portion and a second abutting portion. The first abutting portion is located on the side of the rod away from the head, and the maximum size of the first abutting portion in the radial direction of the first orifice is greater than the diameter of the first orifice. The second abutting portion is located on the side of the head away from the rod, and the maximum size of the second abutting portion in the radial direction of the second orifice is greater than the diameter of the second orifice.

[0013] A through hole extends through the head and shank of the fastener, forming a first opening at the head and a second opening at the shank. The diameter of the first opening restricts the first abutment portion from passing through the through hole, thus confining the first abutment portion to the side of the shank of the fastener away from the head. Similarly, the diameter of the second opening restricts the second abutment portion from passing through the through hole, thus confining the second abutment portion to the side of the head of the fastener away from the shank. In this way, if the fastener breaks (e.g., into a first part and a second part), one of the abutments (one of the first and second abutments) and the first part remain on the housing, while the other abutment portion (the other of the first and second abutments) and the second part fly out with the cover. The connecting portion is pulled by the first and second abutments, constraining the distance between the housing and the cover. The combined action of the first and second contact parts reduces the possibility of the first or second part detaching from the restraint, preventing the equipment cover from flying out indefinitely. The distance the equipment cover flies out is limited by the restraint around the equipment housing, thus improving the safety and explosion-proof performance of the power conversion equipment.

[0014] In one alternative embodiment, the maximum dimension of the abutment portion used to abut the rod portion in the radial direction of the rod portion is smaller than the minor diameter of the external thread on the rod portion.

[0015] Since the external threads on the fasteners need to be threaded into the corresponding threaded holes (located on the equipment cover or housing), it is necessary to control the size of the abutment on one side of the rod. This reduces the impact of the abutment on the threaded connection of the rod to the equipment housing or cover, which is beneficial for the installation of the fasteners.

[0016] In one alternative embodiment, the maximum dimension of the abutment portion of the abutment part in the radial direction of the rod portion is greater than or equal to the maximum dimension of the abutment portion of the abutment part of the rod portion in the radial direction of the rod portion.

[0017] Because the fastener head is relatively large and does not require a threaded connection, the size of the abutment portion on one side of the head can be increased in some cases. On one hand, this makes it easier for the abutment portion to abut against the fastener head, reducing the likelihood of it passing through a through hole and thus decreasing the risk of constraint failure. On the other hand, energy-absorbing or buffering structures can be provided between the abutment portion and the head. A larger abutment portion on the head side facilitates abutment against these structures (energy-absorbing or buffering structures), reducing the risk of energy absorption or buffering failure.

[0018] In one optional embodiment, the power conversion device further includes a first buffer with elasticity, the first buffer being sleeved outside the connecting portion, the first buffer being located between the fastener and one of the abutting portions, one end of the first buffer being used to abut the fastener, and the other end of the first buffer being used to abut one of the abutting portions.

[0019] The first buffer can buffer and absorb the energy of the explosion impact, avoid excessive pressure on the contact part, reduce the possibility of the fastener coming off the restraint after breakage, and also reduce the possibility of the connection between the two contact parts breaking, further improving the safety and explosion-proof performance of the power conversion equipment.

[0020] In one alternative implementation, the first buffer element includes a spring or a rubber sleeve.

[0021] Both the spring and the rubber sleeve are elastic structures that can absorb the energy of an explosive impact.

[0022] In one optional embodiment, the power conversion device further includes a second, elastic buffer, which is sleeved outside the first buffer. One end of the second buffer is used to abut against a fastener, and the other end of the second buffer is used to abut against one of the abutting parts. The first buffer is a rubber sleeve, and the second buffer is a spring.

[0023] By setting up interlocking first and second buffer components, multi-level buffering and multi-level energy absorption are achieved, avoiding excessive pressure on a single buffer component (e.g., only setting the first buffer component), further reducing the possibility of fasteners detaching from the restraints after breakage, and also further reducing the possibility of the connection between the two abutting parts breaking.

[0024] In one alternative embodiment, the connecting part is rope-shaped or rod-shaped.

[0025] When the connector is rope-like, it can be bent and filled into the through-hole of the fastener, reducing the length of the connector exposed outside the fastener and facilitating the rotation of the fastener. After the fastener breaks, the connector is straightened, preventing the two abutting parts from continuously separating, thus constraining the distance between the housing and the cover.

[0026] The rod-shaped connector can also constrain the distance between the equipment housing and the equipment cover. Furthermore, the rod-shaped connector has high rigidity, reducing the possibility of the connector breaking under stress.

[0027] In one optional embodiment, the diameters of the through holes are equal in the arrangement direction of the device housing and the device cover; at least one abutment is spherical, and the diameter of the spherical abutment is larger than the diameter of the through hole; or, at least one abutment is disc-shaped, and the size of the disc-shaped abutment in its own radial direction is larger than the diameter of the through hole.

[0028] Equal-diameter through holes are easy to process. Both spherical and disc-shaped abutment parts can abut against the fasteners when the size is appropriate, reducing the possibility of the abutment part passing through the through hole, thus reducing the risk of broken fasteners falling off the restraint. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of a photovoltaic energy storage system provided in an embodiment of this application;

[0030] Figure 2 This is a schematic diagram of the structure of a power conversion device provided in an embodiment of this application;

[0031] Figure 3 This application provides a topology diagram of a power conversion device according to an embodiment of the present application.

[0032] Figure 4 This application provides a schematic diagram of the structure of a device housing and a device cover according to an embodiment of the present application.

[0033] Figure 5 Schematic diagram of another device housing and another device cover provided in the embodiments of this application;

[0034] Figure 6This is a schematic diagram of the structure of a fastener provided in an embodiment of this application;

[0035] Figure 7 A schematic diagram of a constraint element provided in an embodiment of this application;

[0036] Figure 8 A comparison diagram of the length of the connecting part and the length of the through hole provided for an embodiment of this application;

[0037] Figure 9 This is a schematic diagram of the structure of a fastener after fracture, provided in an embodiment of this application.

[0038] Figure 10 This is a schematic diagram of another constraint element provided in an embodiment of this application;

[0039] Figure 11 A comparison diagram of the length of the connecting part and the length of the through hole provided for an embodiment of this application;

[0040] Figure 12 This is a schematic diagram of another fastener after fracture, provided in an embodiment of this application.

[0041] Figure 13 This application provides a schematic diagram of an external thread structure.

[0042] Figure 14 This is a schematic diagram of the structure of a first buffer provided in an embodiment of this application;

[0043] Figure 15 This is a schematic diagram of the structure of a fastener after fracture, provided in an embodiment of this application.

[0044] Figure 16 This is a schematic diagram of another first buffer provided in an embodiment of this application;

[0045] Figure 17 This is a schematic diagram of the structure of a second buffer provided in an embodiment of this application.

[0046] Figure label:

[0047] 100-Photovoltaic-Storage System; 10-Photovoltaic Module; 20-Power Conversion Equipment; 201-Inverter; 202-Energy Storage Converter; 30-Grid or Load; 40-Energy Storage Battery; 1-Power Conversion Circuit; 11-DC-DC Circuit; 12-DC-AC Circuit; 2-Equipment Housing; 3-Equipment Cover; 4-Accommodation Space; 5-Fastener; 51-Ring; 511-External Thread; 52-Head; 53-Through Hole; 531-First Orifice; 532-Second Orifice; 54-First Part; 55-Second Part; 6-Constraint; 61-Connecting Part; 62-Abutting Part; 621-First Abutting Part; 622-Second Abutting Part; 7-Explosion Relief Joint; 8-First Buffer; 9-Second Buffer. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0049] In the accompanying drawings of the embodiments of this application, solid structures such as components and assemblies are represented by guide lines; structures composed of multiple components are represented by guide lines with parentheses or solid arrows; and hollow structures such as openings, holes, spaces, and cavities are represented by guide lines with hollow arrows.

[0050] Figure 1 An exemplary structure of a photovoltaic energy storage system 100 (solar photovoltaic energy storage power generation system) is shown, including a photovoltaic system and an energy storage system. (Refer to...) Figure 1 In a photovoltaic system, photovoltaic modules 10 utilize the photovoltaic effect to directly convert solar energy into electrical energy. Photovoltaic modules 10 typically include multiple cells connected in series or parallel to achieve a certain output power. Inverter 201 converts the direct current (DC) from photovoltaic modules 10 into alternating current (AC) and transmits the AC to the power grid or load 30. Alternatively, inverter 201 sends the AC to a corresponding prefabricated substation for voltage transformation. The prefabricated substation can convert the low-voltage AC output from inverter 201 into medium-voltage AC, which is then transmitted to a step-up substation and finally to the power grid or load 30.

[0051] Reference in energy storage systems Figure 1The energy storage battery 40 converts direct current (DC) to alternating current (AC) via a power conversion system (PCS) 202. After passing through a prefabricated substation corresponding to the energy storage battery 40, it delivers stable power to the grid or load 30. Alternatively, the power conversion system 202 can also convert AC power from the grid to DC power to charge the energy storage battery 40, and then store the energy within the battery. Or, the energy storage battery 40 can store unstable electrical energy, and the inverter 201 converts the DC power back to AC power to deliver stable power to the grid or load 30.

[0052] This application provides a power conversion device 20. Figure 2 An exemplary structure of a power conversion device 20 is shown, wherein the power conversion device 20 is used to convert one of alternating current and direct current into the other. In one embodiment, the power conversion device 20 is an inverter 201 (auxiliary reference). Figure 1 In one embodiment, the power conversion device 20 is used in a photovoltaic system, and the power conversion device 20 is used to convert direct current (DC) from the photovoltaic module 10 into alternating current (AC) and output it to the grid or load 30. In another embodiment, the power conversion device 20 is an inverter 201 used in an energy storage system, and the power conversion device 20 is used to convert DC from the energy storage battery 40 into AC. In some other embodiments, the power conversion device 20 is an energy storage converter 202 (auxiliary reference). Figure 1 In energy storage systems, the power conversion device 20 is used to convert DC power from the energy storage battery 40 into AC power.

[0053] Figure 3 An exemplary topology diagram of a power conversion device 20 is shown, with reference to... Figure 3 The power conversion device 20 (two-stage mode power conversion device 20) includes a power conversion circuit 1, wherein the power conversion circuit 1 includes a DC-DC circuit 11 and a DC-AC circuit 12, and the input terminal of the DC-DC circuit 11 is used to connect to the photovoltaic module 10 or the energy storage battery 40 (auxiliary reference). Figure 1 The output terminal of DC-DC circuit 11 is electrically connected to the input terminal of DC-AC circuit 12. The output terminal of DC-AC circuit 12 is used to connect to the power grid or load 30 (auxiliary reference). Figure 1 Among them, the DC-DC circuit 11 is used to convert direct current (DC) power, for example, the DC-DC circuit 11 is used to boost or buck the voltage, and the DC-AC circuit 12 is used to convert direct current into alternating current (AC).

[0054] In some other examples, the power conversion device 20 (single-stage mode power conversion device 20) includes a DC-AC circuit 12 but not a DC-DC circuit 11. In this embodiment, the input of the DC-AC circuit 12 is used to connect to the photovoltaic module 10 or the energy storage battery 40, and the output of the DC-AC circuit 12 is used to connect to the power grid or the load 30.

[0055] Understandably, the power conversion circuit 1 in the power conversion device 20 is used to convert direct current from the photovoltaic module 10 or the energy storage battery 40 into alternating current. Furthermore, the power conversion circuit 1 includes a circuit board and electronic components fixed on the circuit board.

[0056] The power conversion device 20 also includes a protective housing for housing the power conversion circuit 1, the protective housing comprising a device shell 2 and a device cover 3. Figure 4 An exemplary structure of a device housing 2 and a device cover 3 is shown, with reference to Figure 4 The device housing 2 and the device cover 3 form a receiving space 4, which is used to house the power conversion circuit 1. Figure 4 The dashed box in the image refers to the power conversion circuit 1). Among them, in... Figure 4 In the illustrated embodiment, the interior of the device housing 2 is recessed towards the side opposite to the device cover 3, forming a cavity inside the device housing 2. This cavity can accommodate the circuit board and electronic components of the power conversion circuit 1. The device cover 3 is a cover-like structure that covers the cavity outside the device housing 2 to seal and shield the internal cavity of the device housing 2.

[0057] in, Figure 4 The structure of the device housing 2 and the device cover 3 is only one example. The structure of the device housing 2 and the device cover 3 can also be other suitable structures. For example, the device cover 3 also has a recessed chamber facing away from the device housing 2. The chambers of the device housing 2 and the chambers of the device cover 3 together form the receiving space 4.

[0058] In one embodiment, when installing the power conversion device 20, the device housing 2 can be installed at a designated location (e.g., a wall, support rod, etc.), with the device cover 3 facing away from the installation location of the device housing 2, meaning that personnel can directly see the device cover 3. In another embodiment, the device cover 3 can also be fixed at a designated location (e.g., a wall, support rod, etc.), with the device housing 2 facing away from the aforementioned designated location, meaning that personnel can directly see the device housing 2.

[0059] To secure the device cover 3 to the device housing 2 (or, to secure the device housing 2 to the device cover 3), the power conversion device 20 also includes fasteners 5, see reference 5. Figure 4Fastener 5 connects the device housing 2 and the device cover 3, thereby fixing the device cover 3 to the device housing 2 (or, fixing the device housing 2 to the device cover 3).

[0060] exist Figure 4 In the illustrated embodiment, the fastener 5 includes a rod 51 and a head 52. The head 52 is fixed to one end of the rod 51 and protrudes towards one side of the rod 51 radially (the Y direction is one of the radial directions of the rod 51). For example, the fastener 5 is a bolt or screw. The rod 51 passes through the device housing 2 and is threadedly connected to the device cover 3. The head 52 is located on the side of the device housing 2 opposite to the device cover 3 and abuts against the device housing 2. When installing the fastener 5, the rod 51 of the fastener 5 is inserted from one side of the device housing 2 and passes through the device housing 2. Rotating the fastener 5 achieves the threaded connection between the rod 51 and the device cover 3, and causes the head 52 of the fastener 5 to abut against the device housing 2, thereby fixing the device cover 3 to the device housing 2. When it is necessary to remove the fastener 5, the fastener 5 is rotated in the opposite direction from one side of the device housing 2, and then the fastener 5 is pulled out to remove it.

[0061] exist Figure 4 In the illustrated embodiment, a threaded hole that mates with the rod 51 is formed on the device cover 3, for example, the threaded hole is machined into the device cover 3. In other embodiments, the threaded hole that mates with the rod 51 is formed on a nut, which is part of the device cover 3, for example, the device cover 3 includes a cover body and a nut, the nut being fixed (e.g., welded, glued, snap-fitted, etc.) to the cover body.

[0062] When the rod 51 is threadedly connected to the equipment cover 3, refer to Figure 4 This design ensures that the fastener 5 does not penetrate the equipment cover 3, meaning that the fastener 5 is not visible from one side of the equipment cover 3. After the power conversion device 20 is installed in the designated position, the equipment cover 3 is positioned away from the installation position of the power conversion device 20, allowing the equipment cover 3 to be directly seen by personnel. The fastener 5 does not protrude from the equipment cover 3. By shielding the fastener 5 with the equipment cover 3, the power conversion device 20 becomes more aesthetically pleasing, and the fastener 5 is also protected, reducing the possibility that the fastener 5 may be rotated arbitrarily by personnel (e.g., non-maintenance personnel).

[0063] In some other embodiments, the fastener 5 passes through both the device housing 2 and the device cover 3.

[0064] Fastener 5 can also secure the device cover 3 to the device housing 2 in other suitable ways, for example, Figure 5 An exemplary diagram shows the structure of another device housing 2 and another device cover 3, with reference to Figure 5The rod 51 passes through the device cover 3 and is threadedly connected to the device housing 2. The head 52 is located on the side of the device cover 3 opposite to the device housing 2 and abuts against the device cover 3. In this embodiment, when installing the fastener 5, the rod 51 of the fastener 5 is inserted from one side of the device cover 3 and passes through the device cover 3, so that the rod 51 is threadedly connected to the device housing 2, and the head 52 of the fastener 5 abuts against the device cover 3, thereby fixing the device cover 3 to the device housing 2. When it is necessary to remove the fastener 5, the fastener 5 is rotated in the opposite direction from one side of the device cover 3, and then the fastener 5 is pulled out.

[0065] exist Figure 5 In the illustrated embodiment, a threaded hole mates with the rod 51 and is formed on the nut, which is part of the device housing 2. For example, the device housing 2 includes a housing and a nut, and the nut is fixed (e.g., welded, glued, snap-fitted, etc.) to the housing. In other embodiments, a threaded hole mates with the rod 51 and is formed on the device housing 2, for example, a threaded hole is machined into the device housing 2.

[0066] exist Figure 5 In the illustrated embodiment, the fastener 5 passes through both the device housing 2 and the device cover 3. In some other embodiments, the fastener 5 passes through the device cover 3 but not through the device housing 2.

[0067] With the head 52 of the fastener 5 located on one side of the equipment cover 3, after the power conversion device 20 is installed in the designated position, the equipment cover 3 is positioned away from the installation position of the power conversion device 20, so that the equipment cover 3 can be directly seen by maintenance personnel. Maintenance personnel can tighten or loosen the fastener 5 by standing on one side of the equipment cover 3, which facilitates maintenance personnel to perform maintenance on the power conversion device 20.

[0068] During operation, the power conversion device 20 may experience internal electronic component failure under extreme conditions such as overvoltage and overtemperature, potentially generating flammable gases such as propane and methane. If these flammable gases ignite and explode within the space enclosed by the device cover 3 and the device shell 2, the internal pressure of the power conversion device 20 will increase. The explosive energy will cause the device cover 3 to detach from the device shell 2, and the fasteners 5 may break. Part of the broken fastener 5 may remain on the device shell 2, while the other part may fly out with the device cover 3. The device cover 3 of the power conversion device 20 flying out under the impact of the explosion will seriously endanger the safety of surrounding equipment and personnel.

[0069] To solve the above problems, this application provides a structure with a constraint function, which passes through the fastener 5 to constrain the broken fastener 5.

[0070] Figure 6 An exemplary structure of a fastener 5 is shown. Figure 6The two dashed boxes in the image refer to device housing 2 and device cover 3, respectively. This can be understood as... Figure 6 The installation method of the medium fastener 5 and Figure 4 The installation method for fastener 5 is similar. (Refer to...) Figure 6 The through hole 53 penetrates the fastener 5 along the arrangement direction (X direction) of the device housing 2 and the device cover 3. For example, if the fastener 5 includes a rod 51 and a head 52, the through hole 53 penetrates both the head 52 and the rod 51. Furthermore, the power conversion device 20 also includes a constraint member 6. Figure 7 An exemplary structure of constraint 6 is shown, with reference to Figure 6 and Figure 7 The constraint member 6 includes a connecting part 61 and two abutting parts 62. The connecting part 61 passes through the through hole 53, and the two abutting parts 62 are respectively fixed to different ends of the connecting part 61 and are both located outside the through hole 53.

[0071] The connecting part 61 can be any suitable structure. Figure 6 and Figure 7 In the illustrated embodiment, the connecting portion 61 is rope-shaped, for example, a metal rope (steel wire rope, etc.), or, for example, a non-metallic rope. The rope-shaped connecting portion 61 can be bent and filled into the through-hole 53 of the fastener 5, reducing the length of the connecting portion 61 exposed outside the fastener 5 and facilitating the rotation of the fastener 5. In other embodiments, the connecting portion 61 is rod-shaped, for example, a metal rod or a non-metallic rod. The rod-shaped connecting portion 61 has greater rigidity, reducing the possibility of breakage under stress.

[0072] Furthermore, the contact portion 62 can be any suitable structure, in Figure 6 and Figure 7 In the illustrated embodiment, the abutment portion 62 is spherical; in other embodiments, the abutment portion 62 is disc-shaped, square-shaped, or other irregularly shaped.

[0073] Figure 6 and Figure 7 The difference lies in whether the connecting portion 61 of the constraint member 6 is completely filled within the through hole 53 when the connecting portion 61 is rope-shaped. Figure 6 In the illustrated embodiment, the connecting portion 61 of the constraint member 6 is completely filled within the through hole 53, and the two abutting portions 62 are respectively fixed to different ends of the fastener 5, respectively blocking the openings at both ends of the through hole 53. Figure 7 In the illustrated embodiment, part of the connecting portion 61 of the constraint member 6 is filled in the through hole 53, and the other part extends out of the through hole 53. The two abutting portions 62 are not fixed to the two ends of the fastener 5.

[0074] The length of the connecting part 61 is greater than the length of the through hole 53. Figure 8 An exemplary comparison of the length of the connecting portion 61 and the length of the through hole 53 is shown. It is understood that the length of the through hole 53 refers to its length in its own extending direction, that is, the length of the through hole 53 in the arrangement direction (X direction) of the device housing 2 and the device cover 3. Furthermore, if the connecting portion 61 is rope-like, it needs to be straightened to measure its length. (Refer to...) Figure 8 The length L1 of the connecting part 61 is greater than the length L2 of the through hole 53.

[0075] Furthermore, the size of each abutment 62 is such that it can limit itself from passing through the through hole 53. That is, when each abutment 62 is pulled toward the through hole 53, the abutment 62 will not completely enter the through hole 53.

[0076] For example, in an embodiment where fastener 5 includes a head 52 and a rod 51, refer back to the previous section. Figure 7 A through hole 53 forms a first opening 531 on the surface of the rod 51 opposite to the head 52, and a through hole 53 forms a second opening 532 on the surface of the head 52 opposite to the rod 51. The two abutting portions 62 include a first abutting portion 621 and a second abutting portion 622. The first abutting portion 621 is located on the side of the rod 51 opposite to the head 52. The maximum size of the first abutting portion 621 in the radial direction of the first opening 531 (the Y direction is one of the radial directions of the first opening 531) is greater than the diameter of the first opening 531. The diameter of the first opening 531 restricts the first abutting portion 621 from passing through the through hole 53, thus restricting the first abutting portion 621 to the side of the rod 51 opposite to the head 52. The second abutment portion 622 is located on the side of the head 52 away from the rod portion 51. The maximum size of the second abutment portion 622 in the radial direction of the second orifice 532 (the Y direction is one of the radial directions of the second orifice 532) is greater than the diameter of the second orifice 532. The diameter of the second orifice 532 will restrict the second abutment portion 622 from passing through the through hole 53, thereby restricting the second abutment portion 622 to the side of the head 52 away from the rod portion 51.

[0077] exist Figure 6 and Figure 7 In the illustrated embodiment, the diameters of the through holes 53 are equal in the arrangement direction (X direction) of the device housing 2 and the device cover 3; that is, the diameters of the first orifice 531 and the second orifice 532 are equal. Both abutment portions 62 are spherical, and the diameter of each spherical abutment portion 62 is larger than the diameter of the through hole 53. This prevents the abutment portion 62 from passing through the through hole 53. It should be noted that the diameter of the sphere refers to the distance between two parallel planes tangent to the surface of the sphere.

[0078] Since the abutment portion 62 does not pass through the through hole 53, the constraint member 6 can restrain the broken fastener 5 in the event of fastener 5 breakage. For example, refer to... Figure 7 Fastener 5 along Figure 7 The dotted line in the figure indicates a break in the structure, which is divided into a first part 54 and a second part 55. The first part 54 includes a portion of the rod 51 and a head 52, and the second part 55 includes another portion of the rod 51. Figure 9 An exemplary structure of a fastener 5 after breakage is shown. The first part 54 is located on the device housing 2, and the second part 55 flies out with the device cover 3. After the connecting part 61 of the constraint member 6 is straightened, the two abutting parts 62 of the constraint member 6 abut against the two ends of the fastener 5 respectively. That is, one abutting part 62 (e.g., the second abutting part 622) abuts against the first part 54, and the other abutting part 62 (e.g., the first abutting part 621) abuts against the second part 55.

[0079] The connecting portion 61 of the constraint member 6 holds the two abutment portions 62, thus holding the equipment shell 2 and the equipment cover 3 together, thereby constraining the distance between the equipment shell 2 and the equipment cover 3. Under the constraint of the constraint member 6, the equipment cover 3 will not fly out indefinitely after being subjected to an explosive impact; the distance the equipment cover 3 flies out will be limited by the constraint member 6 to the vicinity of the equipment shell 2. In addition, since the length of the connecting portion 61 of the constraint member 6 is greater than the length of the fastener 5, the equipment cover 3 and the equipment shell 2 can be separated by a certain distance, forming an explosion relief gap 7 for timely pressure relief.

[0080] In other words, the constraint 6 strengthens the constraint between the equipment housing 2 and the equipment cover 3, reducing the possibility that the equipment cover 3 will fly out due to the explosive impact after the power conversion equipment 20 fails. It also reduces the possibility that the opening between the equipment cover 3 and the equipment housing 2 is too large (the equipment cover 3 would fly out a long distance without the constraint 6). Furthermore, the obstruction of the equipment cover 3 also reduces the possibility that internal fragments of the power conversion equipment 20 (such as fragments of electronic components or circuit boards) will fly out, thus improving the safety and explosion-proof performance of the power conversion equipment 20.

[0081] In addition, this application modifies the fastener 5, reducing the extent of modifications to the equipment housing 2 and equipment cover 3, lowering the difficulty of modifying the power conversion device 20, and reducing production and modification costs.

[0082] In addition, constraint 6 can also be other suitable structures, for example, Figure 10 An exemplary diagram shows another structure of constraint 6, with reference to Figure 10 The connecting part 61 is rod-shaped, and the length of the connecting part 61 is greater than the length of the through hole 53. Figure 11 An exemplary comparison of the length of the connecting portion 61 and the length of the through hole 53 is shown, with reference to... Figure 11 The length L3 of the connecting portion 61 is greater than the length L2 of the through hole 53. Furthermore, in this embodiment, the size of each abutting portion 62 is such that it restricts itself from passing through the through hole 53.

[0083] For example, refer to Figure 10 and Figure 11 The diameters of the through holes 53 are equal in the arrangement direction (X direction) of the equipment housing 2 and the equipment cover 3. That is, the diameters of the two openings of the through holes 53 are equal. When the two openings of the through holes 53 are the first opening 531 and the second opening 532, the diameters of the first opening 531 and the second opening 532 are equal. Both abutment portions 62 are disc-shaped, and the dimension of each disc-shaped abutment portion 62 in its own radial direction (e.g., the Y direction) is larger than the diameter of the through holes 53.

[0084] In the event of fastener 5 breaking, constraint member 6 can restrain the broken fastener 5. For example, refer to... Figure 10 Fastener 5 along Figure 10 The dotted line in the figure indicates a break in the structure, which is divided into a first part 54 and a second part 55. The first part 54 includes a portion of the rod 51 and a head 52, and the second part 55 includes another portion of the rod 51. Figure 12 An exemplary diagram shows the structure after another fastener 5 breaks. Figure 12 Fastener 5 in the middle is along Figure 10 The break occurs at the dotted line position in the image. Figure 12 The two dashed boxes in the image refer to device housing 2 and device cover 3, respectively. (See reference...) Figure 12 The first part 54 is located on the device housing 2, and the second part 55 flies out with the device cover 3. The two abutting parts 62 of the constraint member 6 abut against the two ends of the fastener 5, that is, one abutting part 62 (e.g., the second abutting part 622) abuts against the first part 54, and the other abutting part 62 (e.g., the first abutting part 621) abuts against the second part 55. The connecting part 61 of the constraint member 6 holds the two abutting parts 62, thereby constraining the distance between the device housing 2 and the device cover 3.

[0085] In order to enable the rod portion 51 to be threadedly connected to the equipment cover 3 or the equipment housing 2, the rod portion 51 has an external thread 511. Figure 13 An exemplary structure of an external thread 511 is shown, with reference to Figure 13 External thread 511 is formed on the outer periphery of the rod portion 51. Since the external thread 511 on the fastener 5 needs to be threaded to the corresponding threaded hole (the threaded hole is located on the device cover 3 or device housing 2), it is necessary to control the size of the abutment portion 62 (e.g., the first abutment portion 621) located on one side of the rod portion 51, thereby reducing the impact of the abutment portion 62 located on one side of the rod portion 51 on the threaded connection of the rod portion 51 to the device housing 2 or device cover 3.

[0086] For example, the maximum radial dimension of the abutment portion 62 (e.g., the second abutment portion 622) used to abut the rod portion 51 is smaller than the minor diameter of the external thread 511 on the rod portion 51, which can reduce the impact of the abutment portion 62 on the threaded connection of the fastener 5. Figure 13 Taking the abutment portion 62 as a disc-shaped example, it can be clearly seen that the maximum dimension L4 of the abutment portion 62 in the radial direction of the rod portion 51 is smaller than the minor diameter L5 of the external thread 511. In the embodiment where the abutment portion 62 is originally spherical, the diameter of the ball in the abutment portion 62 is smaller than the minor diameter of the external thread 511.

[0087] It should be noted that the two abutment portions 62 may have the same or different shapes, and their dimensions may be the same or different. For example, in the case where the fastener 5 includes a head 52 and a rod 51, since the head 52 of the fastener 5 is relatively large and does not need to be threaded to other structures, in some cases, the size of the abutment portion 62 on one side of the head 52 can be increased. (Return to reference) Figure 11 The maximum dimension L6 of the abutment portion 62 (e.g., the first abutment portion 621) in the radial direction of the rod portion 51 is greater than the maximum dimension L4 of the abutment portion 62 (e.g., the second abutment portion 622) in the radial direction of the rod portion 51.

[0088] Through the above design, on the one hand, it is more conducive for the abutting part 62 on one side of the head 52 to abut against the head 52, reducing the possibility that the abutting part 62 will pass through the through hole 53, thus reducing the risk of the constraint function of the constraint member 6 failing; on the other hand, other structures for energy absorption or buffering can also be provided between the abutting part 62 on one side of the head 52 and the head 52. The abutting part 62 on the one side of the head 52 is larger in size, which is conducive to the abutting part 62 abutting against the above-mentioned structures (structures for energy absorption or buffering), reducing the risk of the energy absorption or buffering function of the above-mentioned structures failing.

[0089] In some other embodiments, the maximum radial dimension of the abutment portion 62 (e.g., the second abutment portion 622) for the abutment portion 52 is equal to the maximum radial dimension of the abutment portion 62 (e.g., the first abutment portion 621) for the abutment portion 51. For example, in Figures 6 to 9 In the embodiment shown, the two abutting portions 62 are identical in shape and size.

[0090] In some embodiments where the connecting portion 61 is rod-shaped, the constraint member 6 includes a screw and a retainer, the retainer being fixed to the end of the screw shank facing away from the screw head. The screw head is one abutment portion 62, the screw shank is the connecting portion 61, and the retainer is the other abutment portion 62.

[0091] Therefore, in some embodiments, an additional energy-absorbing structure or a buffering structure can be provided between the abutment portion 62 and the fastener 5 to buffer and absorb the energy of the explosion impact. For example, the power conversion device 20 also includes a first buffer member 8 with elasticity. Figure 14 An exemplary embodiment shows the structure of a first buffer 8, wherein, Figure 14 Taking constraint component 6 as an example, refer to Figure 14 The first buffer member 8 is sleeved outside the connecting portion 61 of the constraint member 6, and the first buffer member 8 is located between the fastener 5 and one of the abutting portions 62. Figure 14 In the illustrated embodiment, the first buffer 8 is located between the second abutment 622 on one side of the head 52 and the fastener 5. In other embodiments, the first buffer 8 is located between the first abutment 621 on one side of the rod 51 and the fastener 5.

[0092] In this design, one end of the first buffer member 8 is used to abut against the fastener 5, and the other end of the first buffer member 8 is used to abut against one of the abutting parts 62 (e.g., the second abutting part 622). It should be noted that the two ends of the first buffer member 8 do not always abut against the fastener 5 and one of the abutting parts 62. Instead, after the equipment cover 3 is ejected by an explosive impact and the fastener 5 absorbs energy and breaks, one end of the first buffer member 8 can abut against the fastener 5, and the other end of the first buffer member 8 can abut against the aforementioned abutting part 62. Figure 15 An exemplary diagram illustrates the structure following the breakage of another fastener 5, wherein the fastener 5 along... Figure 14 The dotted line in the image is broken. Figure 15 The two dashed boxes in the image refer to device housing 2 and device cover 3, respectively. Figure 15 After the equipment cover 3 and the equipment shell 2 are separated by the explosion impact, the first buffer 8 is compressed by force.

[0093] The first buffer 8 can buffer and absorb the energy of the explosion impact, prevent the contact part 62 from bearing too much pressure, reduce the possibility of the fastener 5 coming off the restraint part 6 after breakage, and also reduce the possibility of the connection part 61 that holds the two contact parts 62 breaking, further improving the safety and explosion-proof performance of the power conversion device 20.

[0094] The first buffer 8 can be any elastic structure. Figure 14 and Figure 15 In the illustrated embodiment, the first buffer 8 is a spring. Figure 16 An exemplary diagram shows another structure of the first buffer 8, with reference to Figure 16 The first buffer element 8 can be a rubber sleeve. Both the spring and the rubber sleeve are elastic structures capable of absorbing the energy of an explosive impact.

[0095] In some embodiments, the power conversion device 20 may be provided with multiple energy-absorbing structures or buffer structures to achieve multi-stage energy absorption and multi-stage buffering. For example, the power conversion device 20 further includes a second buffer 9 with elasticity. Figure 17 An exemplary embodiment shows the structure of a second buffer 9, with reference to Figure 17 The second buffer 9 is fitted over the first buffer 8, and the second buffer 9 is located between the fastener 5 and one of the abutment portions 62. Figure 17 In the illustrated embodiment, the first buffer 8 and the second buffer 9 are located between the second abutment 622 and the fastener 5. In other embodiments, the first buffer 8 and the second buffer 9 are located between the first abutment 621 and the fastener 5.

[0096] In this design, one end of the second buffer member 9 is used to abut against the fastener 5, and the other end of the second buffer member 9 is used to abut against one of the abutting parts 62 (e.g., the second abutting part 622). It should be noted that both ends of the second buffer member 9 do not necessarily abut against the fastener 5 and one of the abutting parts 62 at all times. Instead, after the equipment cover 3 is ejected by an explosive impact and the fastener 5 absorbs energy and breaks, one end of the second buffer member 9 can abut against the fastener 5, and the other end of the second buffer member 9 can abut against one of the abutting parts 62. Figure 17 In the illustrated embodiment, the first buffer 8 is a rubber sleeve, and the second buffer 9 is a spring. In some other embodiments, the first buffer 8 is a spring, and the second buffer 9 is a rubber sleeve.

[0097] By setting up interlocking first buffer 8 and second buffer 9, multi-level buffering and multi-level energy absorption are achieved, avoiding excessive pressure on a single buffer (e.g., only setting the first buffer 8), further reducing the possibility of the fastener 5 detaching from the constraint 6 after breakage, and also further reducing the possibility of the connecting part 61 that holds the two abutting parts 62 breaking.

[0098] exist Figures 14 to 17 In the illustrated embodiment, because the first abutment portion 621 is located on one side of the rod portion 51 of the fastener 5, the size of the first abutment portion 621 is relatively small, reducing the possibility that the first abutment portion 621 will affect the threaded connection between the fastener 5 and the corresponding threaded hole. The second abutment portion 622 is located on one side of the head 52 of the fastener 5, and a first buffer member 8 is provided between the second abutment portion 622 and the fastener 5. Figure 17 The illustrated embodiment also includes a second buffer 9), which allows the second abutment portion 622 to be larger in size, which is beneficial for the first buffer 8 and the second buffer 9 to abut against the second abutment portion 622.

[0099] In some embodiments, the dimensions of the two abutment portions 62 do not allow them to protrude beyond the outside of the fastener 5. For example, the projection of the first abutment portion 621 on the surface of the rod portion 51 away from the head portion 52 is located within the outer edge of the surface; and the projection of the second abutment portion 622 on the surface of the head portion 52 away from the rod portion 51 is located within the outer edge of the surface.

[0100] The above description is merely a specific embodiment 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 device includes a housing, a cover, and a power conversion circuit, wherein the housing and the cover form a space for housing the power conversion circuit, which is used to convert direct current from a photovoltaic module or an energy storage battery into alternating current. The power conversion device further includes: A fastener that connects the device housing and the device cover, the fastener having a through hole that extends through the fastener along the arrangement direction of the device housing and the device cover; A constraint member includes a connecting portion and two abutting portions. The connecting portion passes through the through hole and has a length greater than the length of the through hole. The two abutting portions are fixed to different ends of the connecting portion and are both located outside the through hole. The size of each abutting portion is sufficient to restrict itself from passing through the through hole.

2. The power conversion device according to claim 1, characterized in that, The fastener includes a rod and a head. The rod has external threads. The head is fixed to one end of the rod and protrudes radially toward one side of the rod. The through hole passes through the head and the rod. The rod passes through the device housing and is threadedly connected to the device cover, the head being located on the side of the device housing opposite to the device cover and abutting against the device housing; or... The rod passes through the device cover and is threadedly connected to the device housing, and the head is located on the side of the device cover away from the device housing and abuts against the device cover.

3. The power conversion device according to claim 2, characterized in that, The through hole forms a first opening on the surface of the rod portion away from the head, and the through hole forms a second opening on the surface of the head portion away from the rod portion; The two abutting portions include a first abutting portion and a second abutting portion. The first abutting portion is located on the side of the rod portion away from the head, and the maximum size of the first abutting portion in the radial direction of the first orifice is greater than the diameter of the first orifice. The second abutting portion is located on the side of the head portion away from the rod portion, and the maximum size of the second abutting portion in the radial direction of the second orifice is greater than the diameter of the second orifice.

4. The power conversion device according to claim 2 or 3, characterized in that, The maximum dimension of the abutting portion used to abut the rod in the radial direction of the rod is smaller than the minor diameter of the external thread on the rod.

5. The power conversion device according to claim 4, characterized in that, The maximum dimension of the abutment portion used to abut the head in the radial direction of the rod portion is greater than or equal to the maximum dimension of the abutment portion used to abut the rod portion in the radial direction of the rod portion.

6. The power conversion device according to any one of claims 1-5, characterized in that, The power conversion device further includes a first buffer with elasticity, which is sleeved outside the connecting part and located between the fastener and one of the abutting parts. One end of the first buffer is used to abut the fastener, and the other end of the first buffer is used to abut the one of the abutting parts.

7. The power conversion device according to claim 6, characterized in that, The first buffer element includes a spring or a rubber sleeve.

8. The power conversion device according to claim 6, characterized in that, The power conversion device further includes a second elastic buffer, which is sleeved outside the first buffer. One end of the second buffer is used to abut against the fastener, and the other end of the second buffer is used to abut against one of the abutting parts. The first buffer is a rubber sleeve, and the second buffer is a spring.

9. The power conversion device according to any one of claims 1-8, characterized in that, The connecting part is rope-shaped or rod-shaped.

10. The power conversion device according to any one of claims 1-9, characterized in that, The diameters of the through holes are equal in the arrangement direction of the equipment housing and the equipment cover; At least one of the abutting portions is spherical, and the diameter of the spherical abutting portion is larger than the diameter of the through hole; or, At least one of the abutting portions is disc-shaped, and the dimension of the disc-shaped abutting portion in its own radial direction is larger than the diameter of the through hole.

Images