Micro inverter and photovoltaic system
Patent Information
- Application Number
- PCT/CN2025/119304
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-25
- Filing Date
- 2025-09-05
- Publication Date
- 2026-10-01
Smart Images
Figure CN2025119304_01102026_PF_FP_ABST
Abstract
Description
Micro inverters and photovoltaic systems Technical Field
[0001] This invention belongs to the field of power electronics technology, specifically relating to a micro inverter and photovoltaic system. Background Technology
[0002] In the photovoltaic field, microinverters have become the optimal choice for residential users and high-risk spaces due to their advantages of easy installation, high conversion efficiency, and low-voltage safety. However, due to size limitations, microinverters generally rely on passive cooling methods. Furthermore, their heat generation is more concentrated. Especially with further miniaturization, heat dissipation performance has become a key technical indicator for stable operation at high power levels.
[0003] As electronic devices directly exposed to outdoor photovoltaic modules, photovoltaic microinverters must possess excellent heat dissipation capabilities. Especially in extremely hot and windless environments during summer, improving heat dissipation performance and maintaining stable operation of the microinverter while limiting the overall size of the device structure has become a pressing issue in this field. Currently, heat dissipation fins are installed on the back of the microinverter casing to improve heat dissipation; however, this results in limited heat dissipation channels or low airflow at these channels, leading to poor heat dissipation performance. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention provides a micro inverter and photovoltaic system with improved heat dissipation.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A micro inverter includes a housing with a backplate and a circuit board disposed in the housing. The housing also includes multiple sets of heat dissipation fins extending rearward from the back of the backplate. The multiple sets of heat dissipation fins include a first heat dissipation fin and a second heat dissipation fin. The first heat dissipation fin and the second heat dissipation fin respectively form an angle greater than 0 and less than 90 degrees with a horizontal plane. The distance between the upper ends of the first heat dissipation fin and the upper ends of the second heat dissipation fin is less than the distance between the lower ends of the first heat dissipation fin and the lower ends of the second heat dissipation fin. The upper ends of the first heat dissipation fin and the upper ends of the second heat dissipation fin are adjacent and form a first heat dissipation channel for airflow from bottom to top.
[0007] In a preferred embodiment, the plurality of heat dissipation fins includes a set of first heat dissipation fins and a set of second heat dissipation fins. The set of first heat dissipation fins includes a plurality of parallel and spaced-apart first heat dissipation fins, and the set of second heat dissipation fins includes a plurality of parallel and spaced-apart second heat dissipation fins. The channels between two adjacent first heat dissipation fins and the channels between two adjacent second heat dissipation fins are aligned with each other and communicate with the first heat dissipation channel.
[0008] In a preferred embodiment, the heat dissipation fins and the backplate are integral.
[0009] In a preferred embodiment, the plurality of heat dissipation fins further includes a third heat dissipation fin, the lower end of which is close to the lower end of the first heat dissipation fin, and the upper end of which is far from the upper end of the first heat dissipation fin, forming a second heat dissipation channel between the third heat dissipation fin and the first heat dissipation fin; the second heat dissipation assembly further includes a fourth heat dissipation fin, the lower end of which is close to the lower end of the second heat dissipation fin, and the upper end of which is far from the upper end of the second heat dissipation fin, forming a third heat dissipation channel between the second heat dissipation fin and the fourth heat dissipation fin.
[0010] In a preferred embodiment, the width of the first heat dissipation channel and / or the second heat dissipation channel and / or the third heat dissipation channel is 2-4 mm.
[0011] In a preferred embodiment, the heat dissipation fins are generally rectangular or trapezoidal in shape, and the heat dissipation fins have a short side perpendicular to the back surface of the back plate and a long side parallel to the back surface of the back plate, the long side extending in a straight line deviating from the vertical direction by 30-45°.
[0012] In a preferred embodiment, a thermally conductive adhesive layer is formed by filling the housing, and the thermally conductive adhesive layer is in contact with the circuit board or the electronic components of the circuit board, and the inner wall of the housing is in contact with the thermally conductive adhesive layer.
[0013] In a preferred embodiment, the microinverter further includes a top cover, and an inner cavity for accommodating a circuit board is provided between the top cover and the housing. The inner surface of the housing is provided with a plurality of heat-conducting protrusions.
[0014] In a preferred embodiment, a thermally conductive gel is provided between the thermally conductive boss and the electronic component.
[0015] The present invention also adopts the following technical solution:
[0016] A photovoltaic system comprising the aforementioned microinverter.
[0017] The present invention adopts the above solution, which has the following advantages compared with the prior art:
[0018] In the micro inverter of the present invention, the first heat dissipation fin and the second heat dissipation fin are arranged adjacently, with the lower ends of the first heat dissipation fin and the second heat dissipation fin far apart from each other and the upper ends close to each other. That is, the distance between the upper ends of the first heat dissipation fin and the second heat dissipation fin is smaller than the distance between the lower ends of the first heat dissipation fin and the second heat dissipation fin. This creates an upward pressure between the first heat dissipation fin and the second heat dissipation fin. In addition, the thermal buoyancy effect results in a faster airflow velocity at the first heat dissipation channel, which can achieve a better heat dissipation effect. Attached Figure Description
[0019] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 is an exploded view of a micro inverter according to an embodiment of the present invention;
[0021] Figure 2 is a perspective view of the housing according to an embodiment of the present invention;
[0022] Figure 3 is a perspective view of the back of the housing according to an embodiment of the present invention;
[0023] Figure 4 is a front view of the back of the housing according to an embodiment of the present invention;
[0024] Figure 5 is a schematic diagram of the interior of the housing according to an embodiment of the present invention.
[0025] in,
[0026] 1. Miniature inverter; 11. Top cover; 12. Housing;
[0027] 131. Third heat dissipation fin; 132. First heat dissipation fin; 133. Second heat dissipation channel; 141. Second heat dissipation fin; 142. Fourth heat dissipation fin; 143. Third heat dissipation channel; 151. Fifth heat dissipation fin; 152. Sixth heat dissipation fin; 16. First heat dissipation channel; 17. Thermally conductive boss; 18. Thermally conductive gel; 19. Thermally conductive adhesive layer;
[0028] 20. Handle; 30. Circuit board; 301. Electronic component; 40. Inner cavity. Detailed Implementation
[0029] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art. It should be noted that the description of these embodiments is for the purpose of aiding understanding the present invention, but does not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0030] In this embodiment, "up", "down", "left" and "right" are based on the up, down, left and right directions shown in Figure 3.
[0031] This embodiment provides a photovoltaic system, including photovoltaic modules and a microinverter, with the microinverter located below the photovoltaic modules. The photovoltaic modules and inverter are two indispensable core components of the photovoltaic system. Together, they convert solar energy into usable electrical energy. The photovoltaic module is a module composed of multiple photovoltaic cells, capable of directly converting sunlight into direct current (DC). The inverter is a power electronic device used to convert the DC power generated by the photovoltaic modules into alternating current (AC) power for grid compatibility or use in residential and industrial equipment. During operation, the photovoltaic modules absorb sunlight and convert it into DC power. This DC power is then transmitted through cables from the photovoltaic modules to the inverter, which converts the DC power into AC power. Finally, the converted AC power can be used for household electricity, industrial equipment, or fed back into the grid.
[0032] A microinverter (full name: micro-grid-connected photovoltaic inverter) is a photovoltaic power generation device relative to traditional centralized inverters. Its typical feature is module-level MPPT (maximum power point tracking) functionality, and its power range is usually below 2000 watts. Unlike traditional solutions, microinverters adopt a distributed architecture, directly providing independent DC-AC conversion for individual photovoltaic modules.
[0033] Traditional photovoltaic (PV) systems typically employ a centralized inverter approach: multiple PV modules are first connected in series (forming strings) or in parallel (forming arrays) to create a DC system, and then the collected DC power is converted to AC power by a single inverter and fed into the grid. In contrast, micro-inverter systems perform power conversion directly at the module level, with each inverter independently managing the output power of its corresponding module. This architecture effectively improves the overall power generation efficiency of the system.
[0034] Further referring to Figures 1 to 5, the micro inverter 1 of this embodiment includes an upper cover 11 and a housing 12 with a back plate. An inner cavity 40 for accommodating a circuit board 30 is provided between the upper cover 11 and the housing 12. The circuit board 30 has multiple electronic components 301, including MOS transistors, diodes, and other devices. The housing 12 also includes multiple sets of heat dissipation fins extending rearward from the back of the back plate. These heat dissipation fins are integrally formed with the back plate of the housing 12. There is no contact thermal resistance between the housing 12 and the heat dissipation fins, and the heat dissipation fins increase the outer surface area of the housing 12, resulting in a larger contact surface between the housing 12 and the environment, thus allowing the environment to remove more heat. Adjacent sets of heat dissipation fins are arranged in a "V" shape, extending the device's lifespan and improving heat dissipation without increasing the overall size.
[0035] Furthermore, the multiple sets of heat dissipation fins include a first heat dissipation fin 132, a second heat dissipation fin 141, a third heat dissipation fin 131, a fourth heat dissipation fin 142, a fifth heat dissipation fin 151, and a sixth heat dissipation fin 152. A heat dissipation channel is formed between two adjacent third heat dissipation fins 131 on the left side, and between two adjacent fourth heat dissipation fins 142 on the right side; a heat dissipation channel is formed between two adjacent fifth heat dissipation fins 151 on the left side, and between two adjacent sixth heat dissipation fins 152 on the right side. The aforementioned left and right heat dissipation channels are symmetrically arranged, and both the left and right heat dissipation channels form an angle greater than 0 and less than 90 degrees with the horizontal plane.
[0036] The heat dissipation fins are rectangular or trapezoidal in shape. The heat dissipation fins have a short side that is perpendicular to the back of the back plate and a long side that is parallel to the back of the back plate. The long side extends in a straight line that deviates from the vertical direction by 30-45°. This allows the air in the heat dissipation channel to exchange heat sufficiently while avoiding excessively slow airflow.
[0037] Furthermore, the first heat dissipation fin 132 and the second heat dissipation fin 141 form an angle greater than 0 and less than 90 degrees with the horizontal plane. The first heat dissipation fin 132 and the second heat dissipation fin 141 are arranged adjacent to each other, with the lower ends of the first heat dissipation fin 132 and the lower ends of the second heat dissipation fin 141 being far apart from each other, while the upper ends of the first heat dissipation fin 132 and the upper ends of the second heat dissipation fin 141 are close together. That is, the distance between the upper ends of the first heat dissipation fin 132 and the upper ends of the second heat dissipation fin 141 is less than the distance between the lower ends of the first heat dissipation fin 132 and the lower ends of the second heat dissipation fin 141. A first heat dissipation channel 16 is formed between the first heat dissipation fin 132 and the second heat dissipation fin 141 for airflow from bottom to top. An upward air pressure is formed between the oppositely arranged first heat dissipation fins 132 and 141. Combined with the thermal buoyancy effect, the air velocity in the first heat dissipation channel 16 is relatively high, and the corresponding heat dissipation effect is also better. Similarly, the lower ends of the fourth heat dissipation fin 142 and the fifth heat dissipation fin 151 are far apart, while the upper ends of the fourth heat dissipation fin 142 and the lower ends of the fifth heat dissipation fin 151 are close together, forming a heat dissipation channel between them. The inclined arrangement of the heat dissipation fins serves to guide airflow, increasing the airflow velocity and adding new heat transfer paths, preventing heat accumulation, and resulting in a more uniform temperature distribution, thereby improving the heat dissipation effect of the device.
[0038] The multiple sets of heat dissipation fins include a set of first heat dissipation fins and a set of second heat dissipation fins. The set of first heat dissipation fins includes multiple parallel and spaced-apart first heat dissipation fins 132. The set of second heat dissipation fins includes multiple parallel and spaced-apart second heat dissipation fins 141. The channels between two adjacent first heat dissipation fins 132 and the channels between two adjacent second heat dissipation fins 141 are aligned with each other and connected to the first heat dissipation channel 16.
[0039] The lower end of the third heat dissipation fin 131 and the lower end of the first heat dissipation fin 132 are close to each other, and the upper end of the third heat dissipation fin 131 and the upper end of the first heat dissipation fin 132 are far apart from each other, forming a second heat dissipation channel 133 between the third heat dissipation fin 131 and the first heat dissipation fin 132; the lower end of the second heat dissipation fin 141 and the lower end of the fourth heat dissipation fin 142 are close to each other, and the upper end of the second heat dissipation fin 141 and the upper end of the fourth heat dissipation fin 142 are far apart from each other, forming a third heat dissipation channel 143 between the second heat dissipation fin 141 and the fourth heat dissipation fin 142. The wind speed at the second heat dissipation channel 133 and the third heat dissipation channel 143 is lower than the wind speed at the first heat dissipation channel 16. Since downward air pressure is formed between the third heat dissipation fin 131 and the first heat dissipation fin 132, and between the second heat dissipation fin 141 and the fourth heat dissipation fin 142, the second heat dissipation channel 133 and the third heat dissipation channel 143 will also have a heat dissipation effect due to the thermal buoyancy effect, but the heat dissipation effect is not as good as that at the first heat dissipation channel 16.
[0040] Furthermore, the widths of the first heat dissipation channel 16, the second heat dissipation channel 133, and the third heat dissipation channel 143 are 2-4 mm. Referring to Figures 2 and 5, the inner surface of the housing 12 is provided with multiple heat-conducting protrusions 17. The heat-conducting protrusions 17 are of varying heights and maintain a certain distance from the circuit board 30 or electronic components 301 to meet safety requirements. The electronic components 301 of the circuit board 30 are preferably positioned at locations corresponding to the heat-conducting protrusions 17. Furthermore, in the design, the multiple heat-conducting protrusions 17 can also be positioned between adjacent heat dissipation fins, for example, between the first heat dissipation fin 132 and the second heat dissipation fin 141, or between the fourth heat dissipation fin 142 and the fifth heat dissipation fin 151. In the design, some areas of the circuit board 30 have openings, and the opening positions are also preferably positioned between the first heat dissipation fin 132 and the second heat dissipation fin 141, or between the fourth heat dissipation fin 142 and the fifth heat dissipation fin 151.
[0041] A thermally conductive insulating layer, specifically thermally conductive gel 18, is provided between the thermally conductive protrusion 17 and the electronic component 301. A thermally conductive adhesive layer 19 is provided between the upper cover 11 and the circuit board 30. Before installing the upper cover 11, thermally conductive adhesive is poured into the inner cavity 40 to form the thermally conductive adhesive layer 19. The thermally conductive adhesive layer 19 is in contact with the circuit board 30 or the electronic components on the circuit board 30, and the inner wall of the housing 12 is in contact with the thermally conductive adhesive layer 19. In the inner cavity formed by the upper cover 11 and the housing 12, thermally conductive adhesive is provided in all areas except for the circuit board 30, the electronic components 301 on the circuit board 30, and the thermally conductive gel. The copper foil in the window area of the circuit board 30 is in direct contact with the thermally conductive adhesive, enhancing the thermal conductivity of the circuit board. Both the thermally conductive gel 18 and the thermally conductive adhesive layer 19 are for the purpose of thermal conduction. Furthermore, the thermally conductive gel has a high thermal conductivity, which can better dissipate heat from local high-temperature areas.
[0042] This embodiment of the micro inverter abandons the traditional heat sink fin design (where the upper and lower ends of the heat sink fins are equally spaced and the heat dissipation channel is vertically upward). Instead, the heat sink fins form a certain angle with the horizontal plane. Within the same volume, it not only has heat dissipation channels in the vertical direction but also on both sides of the vertical direction. This increased number of heat dissipation channels results in a more complete heat dissipation design and better heat dissipation effect, thus improving the overall heat dissipation performance. Furthermore, the first heat dissipation channel between the first and second heat sink fins has a higher airflow velocity. During design, electronic components can be placed in this first heat dissipation channel as much as possible to further improve the heat dissipation effect. In addition, this embodiment uses potting and the application of thermally conductive gel on the thermally conductive protrusions, resulting in a more uniform overall heat distribution and avoiding localized high temperatures.
[0043] In this embodiment, when the micro inverter 1 dissipates heat, the heat generated by the circuit board 30 and the electronic components 301 on the circuit board 30 is first transferred to the surface of the circuit board 30 or the electronic components through the pins; then the heat is transferred to the thermal conductive gel 18 or the thermal conductive adhesive layer 19 through the surface of the circuit board 30 or the electronic components 301; then the thermal conductive adhesive layer 19 directly transfers the heat to the housing 12, and the thermal conductive gel 18 transfers the heat to the housing 12 through the thermal conductive protrusions 17; finally, the housing 12 transfers the heat to the "V"-shaped heat dissipation fins inside the housing 12, and the heat is then transferred to the air through the "V"-shaped heat dissipation fins, thus completing the heat dissipation.
[0044] As indicated in this specification and claims, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, and these steps and elements do not constitute an exclusive list; the method or apparatus may also include other steps or elements. The term "and / or" as used herein includes any combination of one or more of the associated listed items.
[0045] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. Furthermore, the descriptions of "up," "down," "left," and "right" used in this invention are only relative to the relative positional relationships of the various components of the invention in the accompanying drawings.
[0046] The above embodiments are merely illustrative of the technical concept and features of the present invention, and are preferred embodiments. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and they should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made according to the principles of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A micro inverter, comprising a housing with a backplate and a circuit board disposed within the housing, characterized in that, The housing also includes multiple sets of heat dissipation fins extending rearward from the back of the back plate. The multiple sets of heat dissipation fins include a first heat dissipation fin and a second heat dissipation fin. The first heat dissipation fin and the second heat dissipation fin respectively form an angle greater than 0 and less than 90 degrees with the horizontal plane. The distance between the upper ends of the first heat dissipation fin and the upper ends of the second heat dissipation fin is less than the distance between the lower ends of the first heat dissipation fin and the lower ends of the second heat dissipation fin. The upper ends of the first heat dissipation fin and the upper ends of the second heat dissipation fin are adjacent and form a first heat dissipation channel for airflow from bottom to top.
2. The micro inverter according to claim 1, characterized in that, The multiple sets of heat dissipation fins include a set of first heat dissipation fins and a set of second heat dissipation fins. The set of first heat dissipation fins includes multiple parallel and spaced-apart first heat dissipation fins, and the set of second heat dissipation fins includes multiple parallel and spaced-apart second heat dissipation fins. The channels between two adjacent first heat dissipation fins and the channels between two adjacent second heat dissipation fins are aligned with each other and communicate with the first heat dissipation channel.
3. The micro inverter according to claim 2, characterized in that, The heat dissipation fins and the back plate are integrated.
4. The micro inverter according to claim 1, characterized in that, The plurality of heat dissipation fins further includes a third heat dissipation fin, the lower end of which is close to the lower end of the first heat dissipation fin, and the upper end of which is far from the upper end of the first heat dissipation fin, forming a second heat dissipation channel between the third heat dissipation fin and the first heat dissipation fin; the second heat dissipation assembly further includes a fourth heat dissipation fin, the lower end of which is close to the lower end of the second heat dissipation fin, and the upper end of which is far from the upper end of the second heat dissipation fin, forming a third heat dissipation channel between the second heat dissipation fin and the fourth heat dissipation fin.
5. The micro inverter according to claim 4, characterized in that, The width of the first heat dissipation channel and / or the second heat dissipation channel and / or the third heat dissipation channel is 2-4 mm.
6. The micro inverter according to claim 1, characterized in that, The heat dissipation fins are generally rectangular or trapezoidal in shape. The heat dissipation fins have a short side that is perpendicular to the back of the back plate and a long side that is parallel to the back of the back plate. The long side extends in a straight line that deviates from the vertical direction by 30-45°.
7. The micro inverter according to claim 1, characterized in that, A thermally conductive adhesive layer is formed by filling the housing, and the thermally conductive adhesive layer is in contact with the circuit board or the electronic components of the circuit board. The inner wall of the housing is in contact with the thermally conductive adhesive layer.
8. The micro inverter according to claim 7, characterized in that, The micro inverter also includes a top cover, and there is an inner cavity between the top cover and the housing for accommodating a circuit board. The inner surface of the housing is provided with multiple heat-conducting protrusions.
9. The micro inverter according to claim 8, characterized in that, Thermally conductive gel is provided between the thermally conductive boss and the electronic component.
10. A photovoltaic system, characterized in that, The photovoltaic system further includes a microinverter as described in any one of claims 1 to 9.