Photovoltaic inverter and photovoltaic power generation system

Abstract

The present application provides a photovoltaic inverter and a photovoltaic power generation system. The photovoltaic inverter has good effect. The photovoltaic inverter comprises at least one power semiconductor device, a radiator, a lower box body, and an upper box body, wherein the lower box body and the upper box body are arranged in a first direction; the lower box body is used for accommodating the at least one power semiconductor device; the radiator comprises two condensers and at least one evaporator; and the evaporator is configured to be connected to the condensers by means of two-phase pipes, in contact connection to the outer wall of the lower box body, and connected to the power semiconductor device in a heat-conductive manner. The upper box body comprises a middle partition plate and two ventilation openings oppositely arranged in a second direction; the middle partition plate is of a stepped structure in the second direction, and used for dividing a cavity of the upper box body into two sub-cavities; each sub-cavity is used for accommodating one condenser; and the two condensers are spaced apart from each other in the second direction.

Description

Photovoltaic inverter and photovoltaic power generation system

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on November 15, 2023, with application number 202311524620.0, and priority to the Chinese patent application entitled “Photovoltaic Inverter and Photovoltaic Power Generation System”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of photovoltaic technology, and in particular to a photovoltaic inverter and a photovoltaic power generation system. Background Art

[0003] In photovoltaic power generation systems, photovoltaic inverters convert input direct current (DC) into alternating current (AC). Direct current is also called direct current, or DC for short. Alternating current is also called alternating current, or AC for short. Typically, photovoltaic inverters are equipped with power transistors, which have relatively high output power and therefore generate significant heat.

[0004] However, the heat dissipation effect of the existing photovoltaic inverter is poor, which affects the life of the power tube in the photovoltaic inverter and further affects the service life of the photovoltaic inverter.

[0005] Summary of the Invention

[0006] The present application provides a photovoltaic inverter and a photovoltaic power generation system, which can improve the heat dissipation effect of the photovoltaic inverter and extend the service life of the photovoltaic inverter.

[0007] In a first aspect, a photovoltaic inverter is provided, comprising at least one power semiconductor device, a heat sink, an upper housing, and a lower housing. The lower housing is configured to accommodate the power semiconductor device. The heat sink comprises two condensers and at least one evaporator, the evaporator being configured to: connect the condensers via two-phase piping, contact the outer wall of the lower housing, and thermally connect the power semiconductor device. The upper housing and the lower housing are arranged along a first direction, the upper housing comprising a middle partition and two vents arranged oppositely along a second direction, the middle partition forming a stepped structure along the second direction, the middle partition being configured to divide the cavity of the upper housing into two sub-cavities, each sub-cavity being configured to accommodate a condenser, the two condensers being arranged at intervals along the second direction.

[0008] In the photovoltaic inverter provided by the embodiment of the present application, the refrigerant in the evaporator can absorb the heat generated by the power semiconductor devices in the lower box and evaporate into a gaseous state. The gaseous refrigerant can enter each condenser in the upper box through the gas pipeline in the two-phase pipeline connected to each condenser. The outside air flows into each individual sub-cavity of the upper box along a vent of the upper box, takes away part of the heat of each condenser in the process of flowing in each individual sub-cavity, and flows out of each individual sub-cavity along another vent of the upper box. In this way, the gaseous refrigerant in the condenser in the upper box will cool and condense into a liquid refrigerant. Under the action of gravity, each condenser in the upper box will flow back to the evaporator through the liquid pipeline in the two-phase pipeline, thereby achieving heat dissipation for the power semiconductor devices of the photovoltaic inverter.

[0009] On the one hand, because the condenser and evaporator are arranged along the first direction, the refrigerant in the evaporator can be vaporized and enter the condenser without the need for a pump or other power device, and the refrigerant condensed into a liquid by the condenser can flow back to the evaporator under the action of gravity, thereby achieving efficient circulation of the refrigerant between the evaporator and the evaporator. On the other hand, because the middle partition has a stepped structure along the second direction, each individual sub-cavity in the upper box body also has a stepped structure along the second direction. In addition, each condenser is arranged in a separate sub-cavity, and the two condensers are arranged at intervals along the second direction. In this way, not only will the heat dissipated by each sub-cavity not affect each other, thus avoiding the occurrence of thermal cascades, but also, given a certain size of the upper box body, a sufficient condensation area is guaranteed. In addition, the heat dissipation effect of the photovoltaic inverter is improved, and the service life of the photovoltaic inverter is extended.

[0010] In addition, under the premise that the size of the upper box body is certain, by setting a stepped structure middle partition in the upper box body, the heat dissipated by each sub-cavity can be isolated, ensuring a sufficient condensation area, simplifying the processing and assembly process of the photovoltaic inverter, and reducing the production cost of the photovoltaic inverter.

[0011] In one implementation, the middle partition includes three base plates, two of which are spaced apart along a first direction and whose projections along the first direction do not overlap, or two of which are spaced apart along a third direction and whose projections along the third direction do not overlap. Another base plate is used to connect the two base plates. In this case, along the arrangement direction of the two base plates, the projection of each base plate overlaps with the projection of one condenser.

[0012] The two substrates are spaced apart along a first direction, and the projections of the two substrates along the first direction do not overlap. That is, the middle partition divides the cavity of the upper case into two sub-cavities arranged opposite each other along the first direction. Thus, outside air flows into the two sub-cavities arranged opposite each other along the first direction through a vent in the upper case, taking away part of the heat from each condenser as it flows through each individual sub-cavity, and then flows out of each individual sub-cavity through another vent in the upper case. Thus, the gaseous refrigerant in the condenser in the upper case cools and condenses into liquid refrigerant. Under the action of gravity, each condenser in the upper case flows back to the evaporator through the liquid pipeline in the two-phase pipeline, thereby dissipating heat for the power semiconductor devices of the photovoltaic inverter.

[0013] The two substrates are spaced apart along the third direction, and their projections along the third direction do not overlap. That is, the middle partition divides the cavity of the upper case into two sub-cavities arranged opposite each other along the third direction. Thus, outside air flows through a vent in the upper case into the two sub-cavities arranged opposite each other along the third direction, taking away some of the heat from each condenser as it flows through each individual sub-cavity, and then flows out of each individual sub-cavity through another vent in the upper case. Thus, the gaseous refrigerant in the condenser in the upper case cools and condenses into liquid refrigerant. Under the action of gravity, each condenser in the upper case flows back to the evaporator through the liquid pipeline in the two-phase pipeline, thereby dissipating heat for the power semiconductor devices of the photovoltaic inverter.

[0014] In one implementation, the upper case includes two side panels arranged opposite each other along a first direction, two base panels arranged opposite each other along the first direction, and a distance between one of the two base panels and one of the two side panels equals a distance between the other of the two base panels and the other of the two side panels. In this way, the two sub-cavities of the upper case are centrally symmetrical about a centerline of the third base panel along a third direction, ensuring a high density of individual sub-cavities within the upper case while maintaining a constant size.

[0015] In an implementation, the number of the evaporator is one, and the distance between one of the two condensers and a side plate is smaller than the distance between the other condenser and the side plate.

[0016] Because the flow resistance of gas is related to height, when the two sub-cavities are distributed along the first direction, the height of the condenser in the upper sub-cavity is set higher than the height of the condenser in the lower sub-cavity. In this way, for a one-to-two radiator, the height difference between the two sub-cavities can be avoided, which can prevent the uneven amount of gaseous refrigerant in the evaporator from entering the two condensers, thereby avoiding uneven distribution of heat required to be dissipated by the two condensers.

[0017] In one implementation, the upper case includes two additional side panels arranged opposite each other along a third direction. Two base plates are respectively arranged opposite each other along the third direction, and the distance between one of the two base plates and one of the other two side plates is equal to the distance between the other of the two base plates and the other of the other two side plates. In this way, the two sub-cavities of the upper case are centrally symmetrical about the centerline of the third base plate along the first direction. This ensures a high density of individual sub-cavities within the upper case, provided the dimensions of the upper case along the first, third, and second directions are constant.

[0018] In one implementation, the photovoltaic inverter further includes two fan groups, each group including at least one fan. The air inlet of each fan faces a vent, and the air outlet of each fan group faces a condenser. In this way, each sub-cavity forms an air duct, and the air flow within each sub-cavity cools the gaseous refrigerant in the condenser within each sub-cavity.

[0019] In one implementation, each fan is positioned closer to one vent than to the other; or even more so, each fan is positioned equidistant from one vent. This placement of each fan near one of the two vents not only ensures air in the upper housing cavity flows from one vent to the other, but also simplifies the fan assembly process.

[0020] In one implementation, the projection of each fan in each sub-chamber overlaps with the projection of the condenser in each sub-chamber along the second direction. In this way, the wind from the air outlet side of each fan group can quickly cool the gaseous refrigerant in the condenser, thereby improving the cooling efficiency of the gaseous refrigerant in the condenser.

[0021] In one implementation, there are two evaporators, each connected to a condenser via a two-phase pipeline. That is, the evaporators and condensers in the radiator are arranged one-to-one. This simplifies the assembly process between the evaporators and condensers and reduces costs.

[0022] In a second aspect, a photovoltaic power generation system is provided, comprising a photovoltaic component and a photovoltaic inverter as described in the first aspect and any one of the possible implementations of the first aspect, wherein the photovoltaic component is used to convert light energy into electrical energy, and the photovoltaic inverter is used to convert direct current from the photovoltaic component into alternating current.

[0023] The technical effects of the second aspect mentioned above can be referred to the corresponding description in the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a schematic diagram of a photovoltaic power generation system provided in an embodiment of the present application.

[0025] FIG2 is a schematic diagram of a three-dimensional structure of a photovoltaic inverter provided in an embodiment of the present application.

[0026] FIG3 is a schematic diagram of the two-dimensional structure of the photovoltaic inverter shown in FIG2 .

[0027] FIG4 is a schematic diagram of the three-dimensional structure of another photovoltaic inverter provided in an embodiment of the present application.

[0028] FIG5 is a schematic diagram of the two-dimensional structure of the photovoltaic inverter shown in FIG4 .

[0029] FIG6 is a schematic diagram of a three-dimensional structure of another photovoltaic inverter provided in an embodiment of the present application.

[0030] FIG7 is a schematic diagram of the two-dimensional structure of the photovoltaic inverter shown in FIG6 .

[0031] FIG8 is a schematic diagram of a three-dimensional structure of another photovoltaic inverter provided in an embodiment of the present application.

[0032] FIG9 is a schematic diagram of the two-dimensional structure of the photovoltaic inverter shown in FIG8 .

[0033] FIG10 is a schematic diagram of a three-dimensional structure of another photovoltaic inverter provided in an embodiment of the present application.

[0034] FIG11 is a schematic diagram of the two-dimensional structure of the photovoltaic inverter shown in FIG10 .

[0035] FIG12 is a schematic diagram of a three-dimensional structure of another photovoltaic inverter provided in an embodiment of the present application.

[0036] FIG13 is a schematic diagram of the two-dimensional structure of the photovoltaic inverter shown in FIG12 .

[0037] FIG14 is a schematic diagram of a three-dimensional structure of another photovoltaic inverter provided in an embodiment of the present application.

[0038] FIG15 is a schematic diagram of the two-dimensional structure of the photovoltaic inverter shown in FIG14 .

[0039] FIG16 is a schematic diagram of the three-dimensional structure of another photovoltaic inverter provided in an embodiment of the present application.

[0040] FIG17 is a schematic diagram of the two-dimensional structure of the photovoltaic inverter shown in FIG16 .

[0041] FIG18 is a schematic diagram of the three-dimensional structure of another photovoltaic inverter provided in an embodiment of the present application.

[0042] FIG19 is a schematic diagram of the two-dimensional structure of the photovoltaic inverter shown in FIG18 .

[0043] FIG20 is a schematic diagram of the three-dimensional structure of another photovoltaic inverter provided in an embodiment of the present application.

[0044] FIG21 is a schematic diagram of the two-dimensional structure of the photovoltaic inverter shown in FIG20 .

[0045] FIG22 is a schematic diagram of the three-dimensional structure of a photovoltaic inverter container device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

[0047] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in this article is merely a way to describe the association relationship of associated objects, indicating that three relationships can exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0048] In the embodiments of the present application, prefixes such as "first", "second", and "third" are used only to distinguish different description objects, and have no limiting effect on the position, order, priority, quantity or content of the described objects. In the embodiments of the present application, the use of prefixes such as ordinal numbers to distinguish description objects does not constitute a limitation on the described objects. For the statement of the described objects, please refer to the description in the context of the claims or embodiments, and no unnecessary limitations should be constituted due to the use of such prefixes. In addition, in the description of this embodiment, unless otherwise specified, the meaning of "plurality" is two or more.

[0049] The terms "up", "down", "left", "right", "front", "back", "top", "bottom", "inside", "outside", etc. in the embodiments of the present application indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the present application.

[0050] References to "some embodiments" and the like in this specification mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in some embodiments" and the like that appear in different places in 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 "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0051] The “perpendicular” mentioned in this application is not strictly perpendicular, but within the allowable error range. The “parallel” is not strictly parallel, but within the allowable error range.

[0052] In the embodiments of this application, the same reference numerals represent the same component or part. In the embodiments of this application, for multiple identical parts, only one of the parts may be labeled with a reference numeral in the drawings as an example. The same reference numerals apply to other identical parts or components. In addition, the sizes and dimensions of the parts shown in the drawings are for illustrative purposes only.

[0053] An embodiment of the present application provides a photovoltaic inverter, which includes at least one power semiconductor device, a radiator, an upper box and a lower box. The lower box is used to accommodate at least one power semiconductor device. The radiator includes two condensers and at least one evaporator. The evaporator is used to: connect the condensers with two-phase pipelines, contact and connect the outer wall of the lower box, and heat-conductingly connect the power semiconductor devices. The upper box and the lower box are arranged along a first direction, and the upper box includes a middle partition and two vents arranged oppositely along a second direction. The middle partition is a stepped structure along the second direction. The middle partition is used to divide the cavity of the upper box into two sub-cavities, each sub-cavity is used to accommodate a condenser, and the two condensers are arranged at intervals along the second direction.

[0054] In the photovoltaic inverter provided by the embodiment of the present application, the refrigerant in the evaporator can absorb the heat generated by the power semiconductor devices in the lower box and evaporate into a gaseous state. The gaseous refrigerant can enter each condenser in the upper box through the gas pipeline in the two-phase pipeline connected to each condenser. The outside air flows into each individual sub-cavity of the upper box along a vent of the upper box, takes away part of the heat of each condenser in the process of flowing in each individual sub-cavity, and flows out of each individual sub-cavity along another vent of the upper box. In this way, the gaseous refrigerant in the condenser in the upper box will cool and condense into a liquid refrigerant. Under the action of gravity, each condenser in the upper box will flow back to the evaporator through the liquid pipeline in the two-phase pipeline, thereby achieving heat dissipation for the power semiconductor devices of the photovoltaic inverter.

[0055] On the one hand, because the condenser and evaporator are arranged along the first direction, the refrigerant in the evaporator can be vaporized and enter the condenser without the need for a pump or other power device, and the refrigerant condensed into a liquid by the condenser can flow back to the evaporator under the action of gravity, thereby achieving efficient circulation of the refrigerant between the evaporator and the evaporator. On the other hand, because the middle partition has a stepped structure along the second direction, each individual sub-cavity in the upper box body also has a stepped structure along the second direction. In addition, each condenser is arranged in a separate sub-cavity, and the two condensers are arranged at intervals along the second direction. In this way, not only will the heat dissipated by each sub-cavity not affect each other, thus avoiding the occurrence of thermal cascades, but also, given a certain size of the upper box body, a sufficient condensation area is guaranteed. In addition, the heat dissipation effect of the photovoltaic inverter is improved, and the service life of the photovoltaic inverter is extended.

[0056] In addition, under the premise that the size of the upper box body is certain, by setting a stepped structure middle partition in the upper box body, the heat dissipated by each sub-cavity can be isolated, ensuring a sufficient condensation area, simplifying the processing and assembly process of the photovoltaic inverter, and reducing the production cost of the photovoltaic inverter.

[0057] The embodiment of the present application further provides a photovoltaic power generation system. The photovoltaic power generation system provided by the embodiment of the present application will be described in detail below with reference to FIG1 .

[0058] FIG1 is a schematic diagram of a photovoltaic power generation system provided in an embodiment of the present application. As shown in FIG1 , the photovoltaic power generation system 1 provided in an embodiment of the present application includes one or more photovoltaic modules 10, a photovoltaic inverter 20, a box-type substation 30, a three-phase AC power grid 40, a DC cable 50, a first AC cable 60, and a second AC cable 70. Among them, one or more photovoltaic modules 10 are connected to the photovoltaic inverter 20 via the DC cable 50, and the connection relationship between the photovoltaic modules 10 and the photovoltaic inverter 20 can be a many-to-one connection. The photovoltaic inverter 20 converts DC power into AC power, and the AC side of the photovoltaic inverter 20 is connected to the box-type substation 30 via the first AC cable 60. The box-type substation 30 is connected to the three-phase AC power grid 40 via the second AC cable 70. In this way, the AC power output by the photovoltaic inverter 20 flows into the three-phase AC power grid 40 after passing through the box-type substation 30.

[0059] The photovoltaic power generation system 1 is a power generation system that uses the photovoltaic effect of semiconductor materials to convert solar radiation energy into electrical energy. The photovoltaic power generation system 1 provided in the embodiment of the present application can empower electric vehicles. The electric vehicles include pure electric vehicles, hybrid vehicles, extended-range electric vehicles, plug-in hybrid vehicles or new energy vehicles. Among them, pure electric vehicles are also called pure electric vehicle / battery electric vehicle, or simply pure EV / battery EV. Hybrid vehicles are also called hybrid electric vehicles, or simply HEV. Extended-range electric vehicles are also called range extended electric vehicles, or simply REEV. Plug-in hybrid vehicles are also called plug-in hybrid electric vehicles, or simply PHEV. New energy vehicles are also called new energy vehicles, or simply NEV.

[0060] The photovoltaic module 10, also known as a photovoltaic array, includes multiple photovoltaic strings. Photovoltaic is also called photovoltaic, or simply PV. A string is also called a string. Each photovoltaic string includes multiple photovoltaic panels connected in series. Photovoltaic panels are used to convert light energy into electrical energy. The electrical energy generated by photovoltaic panels is DC power. The voltage across a photovoltaic string is equal to the sum of the voltages generated by the multiple photovoltaic panels. The output power of a photovoltaic module can be expressed as the electrical energy output per unit time by the photovoltaic module.

[0061] In photovoltaic power generation system 1, the area of ​​each photovoltaic module 10 is generally fixed. When the light intensity remains constant, the larger the angle between the light incident on photovoltaic module 10 and the plane on which photovoltaic module 10 is located, that is, the smaller the angle of incidence of the light on photovoltaic module 10, the more electrical energy the photovoltaic module 10 outputs. When the light incident on photovoltaic module 10 is perpendicular, that is, the angle between the light and the plane on which photovoltaic module 10 is located is 90°, reaching its maximum value, the power output of photovoltaic module 10 reaches its maximum.

[0062] The box-type substation 30, also known as a box-type transformer 30, is a compact power distribution device that integrates high-voltage switchgear, distribution transformers, and low-voltage distribution equipment according to a specific wiring scheme. For example, the box-type transformer 30 integrates low-voltage cabinets, transformers, ring main units, auxiliary power supplies, and other equipment into a container, providing a highly integrated power distribution solution for medium-voltage grid-connected photovoltaic power plants.

[0063] When the photovoltaic power generation system 1 includes a plurality of photovoltaic modules 10 , the photovoltaic power generation system 1 further includes a combiner box, which is used to combine the direct current generated by the plurality of photovoltaic modules 10 and input the combined output into the photovoltaic inverter 20 .

[0064] Each photovoltaic inverter 20 is used to convert input DC to AC, i.e., perform DC-AC conversion. Photovoltaic inverter 20 may also be referred to as a DC-AC converter. The specific structure of photovoltaic inverter 20 provided in the embodiments of the present application is described in detail below with reference to Figures 2 to 21.

[0065] As shown in FIG. 2 to FIG. 13 , FIG. 14 , FIG. 16 , FIG. 18 and FIG. 20 , the housing 210 of the photovoltaic inverter 20 includes a lower housing 211 and an upper housing 212 that are arranged opposite to each other along a first direction.

[0066] Lower case 211 includes a top plate and a bottom plate arranged opposite each other along a first direction, a left plate and a right plate arranged opposite each other along a second direction, and a front plate and a rear plate arranged opposite each other along a third direction. The top plate, the bottom plate, the front plate, the rear plate, the left plate, and the right plate collectively form a housing for lower case 211.

[0067] In one embodiment, the first direction, the third direction, and the second direction are perpendicular to each other. It should be understood that the first direction can also be referred to as the up-down direction of the photovoltaic inverter 20 or the gravity direction of the photovoltaic inverter 20, the third direction can also be referred to as the front-back direction of the photovoltaic inverter 20, and the second direction can also be referred to as the left-right direction of the photovoltaic inverter 20.

[0068] As shown in Figures 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20, the upper box body 212 includes four side panels, two of which are a lower side panel 2121 and an upper side panel 2122, and the other two side panels are a front side panel 2123 and a rear side panel 2124. The lower side panel 2121 and the upper side panel 2122 are arranged relative to each other along a first direction, the front side panel 2123 and the rear side panel 2124 are arranged relative to each other along a third direction, the lower side panel 2121, the upper side panel 2122, the front side panel 2123 and the rear side panel 2124 are mutually enclosed to form a cavity, and the cavity of the upper box body 212 includes two vents arranged relative to each other along a second direction, namely, a vent M1 and a vent M2.

[0069] In one embodiment, in order to prevent the components contained in the containing cavity of the lower box body 211 from being affected by the environment and thus reducing their service life, the containing cavity of the lower box body 211 is generally a closed cavity.

[0070] In one embodiment, to reduce production costs, the lower box body 211 and the upper box body 212 can share a wall. For example, the top plate of the lower box body 211 and the lower side plate 2121 of the upper box body 212 are a single plate. In this way, the top plate of the lower box body 211 or the lower side plate 2121 of the upper box body 212 divides the box body 210 into the accommodating cavity of the lower box body 211 and the accommodating cavity of the upper box body 212.

[0071] In another embodiment, to prevent heat from flowing back from the upper housing 212 into the lower housing 211, the lower housing 211 and the upper housing 212 do not share a common wall. In this embodiment, the photovoltaic inverter 20 further includes a connector for connecting the lower housing 211 and the upper housing 212. For example, the connector includes a plurality of beams, each having a dimension along a first direction equal to the distance between the lower housing 211 and the upper housing 212. Each beam is used to support and securely connect the top plate of the lower housing 211 and the lower side plate 2121 of the upper housing 212, and to support the upper housing 212.

[0072] As shown in FIG. 2 to FIG. 21 , the upper box body 212 further includes a middle partition plate 2125 . The middle partition plate 2125 has a stepped structure along the second direction. The middle partition plate 2125 is used to separate the cavity of the upper box body 212 into two sub-cavities.

[0073] In some embodiments, as shown in FIG. 2 to FIG. 21 , the middle partition plate 2125 includes three substrates, two of which are a first substrate 21251 and a second substrate 21252 , and the other substrate is a third substrate 21253 .

[0074] In one embodiment, as shown in Figures 2 to 13 , along a first direction, a first substrate 21251 and a second substrate 21252 are spaced apart, and their projections do not overlap. A third substrate 21253 connects the first and second substrates 21251, 21252. Thus, the middle partition 2125 divides the cavity of the upper case 212 into two sub-cavities arranged opposite each other along the first direction. In other words, the two sub-cavities of the upper case 212 are distributed in the vertical direction.

[0075] Furthermore, in one embodiment, along the first direction, the first substrate 21251 and the second substrate 21252 are arranged opposite the lower side plate 2121 and the upper side plate 2122, respectively. The distance between the first substrate 21251 and the upper side plate 2122 is equal to the distance between the second substrate 21252 and the lower side plate 2121, or the distance between the first substrate 21251 and the lower side plate 2121 is equal to the distance between the second substrate 21252 and the upper side plate 2122. In this way, the two sub-cavities of the upper case 212 are symmetrical about the centerline of the third substrate 21253 along the third direction. When the dimensions of the upper case 212 along the first, third, and second directions are constant, a high-density arrangement of the individual sub-cavities of the upper case 212 is ensured.

[0076] Furthermore, in one embodiment, at least one of the two opposing side surfaces of the middle partition 2125 along the third direction is fixedly connected to the inner wall of the upper case 212. In another embodiment, the photovoltaic inverter 20 further includes a first fixing plate 2126, which is arranged between the first substrate 21251 and the upper side plate 2122 along the first direction. The first fixing plate 2126 is fixedly connected to the first substrate 21251 and the upper side plate 2122, respectively. Furthermore, the photovoltaic inverter 20 further includes a second fixing plate 2127, which is arranged between the second substrate 21252 and the lower side plate 2121 along the first direction. The second fixing plate 2127 is fixedly connected to the second substrate 21252 and the lower side plate 2121, respectively.

[0077] In another embodiment, as shown in Figures 14 to 21, along the third direction, the first substrate 21251 and the second substrate 21252 are spaced apart, and their projections do not overlap. The third substrate 21253 is used to connect the first substrate 21251 and the second substrate 21252. In this way, the middle partition 2125 divides the cavity of the upper case 212 into two sub-cavities arranged opposite each other along the third direction. In other words, the two sub-cavities of the upper case 212 are distributed in the front-to-back direction.

[0078] Furthermore, in one embodiment, along the first direction, the first substrate 21251 and the second substrate 21252 are arranged opposite the front side panel 2123 and the rear side panel 2124, respectively. The distance between the first substrate 21251 and the front side panel 2123 is equal to the distance between the second substrate 21252 and the rear side panel 2124, or the distance between the first substrate 21251 and the rear side panel 2124 is equal to the distance between the second substrate 21252 and the front side panel 2123. In this way, the two sub-cavities of the upper case 212 are symmetrical about the centerline of the third substrate 21253 along the first direction. When the dimensions of the upper case 212 along the first, third, and second directions are constant, a high-density arrangement of the individual sub-cavities of the upper case 212 is ensured.

[0079] Furthermore, in one embodiment, at least one of the two opposite side surfaces of the middle partition 2125 along the first direction is fixedly connected to the inner wall of the upper case 212. In another embodiment, the photovoltaic inverter 20 further includes a first fixing plate 2126, which is arranged along the third direction between the first substrate 21251 and the rear side plate 2124. The first fixing plate 2126 is fixedly connected to the first substrate 21251 and the rear side plate 2124, respectively. Furthermore, the photovoltaic inverter 20 further includes a second fixing plate 2127, which is arranged along the third direction between the second substrate 21252 and the front side plate 2123. The second fixing plate 2127 is fixedly connected to the second substrate 21252 and the front side plate 2123, respectively.

[0080] In some embodiments, the three substrates of the middle separator 2125 are processed by an integrated molding process, thereby simplifying the processing technology of the middle separator 2125 and reducing the production cost of the middle separator 2125.

[0081] In some embodiments, the angles between the third substrate 21253 and the first substrate 21251 and the second substrate 21252 are between 90° and 180°, so that external air can easily flow out of each individual sub-cavity through another vent.

[0082] In some embodiments, as shown in FIG. 2 to FIG. 21 , the photovoltaic inverter 20 further includes a circuit board 221 and at least one power semiconductor device 222 . The circuit board 221 is used to fix each power semiconductor device 222 .

[0083] The circuit board 221 is accommodated in the accommodating cavity of the lower case 211, and the circuit board 221 is arranged relative to any side panel of the lower case 211. For the convenience of description, this application describes the arrangement of the circuit board 221 relative to the front panel of the lower case 211 along the third direction as shown in Figures 2 to 21 as an example.

[0084] In the embodiment of the present application, the circuit board 221 may also be referred to as a printed circuit board assembly, which is also called a printed circuit board assembly, or PCBA for short.

[0085] For example, the power semiconductor device is an insulated gate bipolar transistor (IGBT) or a power inductor. An insulated gate bipolar transistor is also called an insulated gate bipolar transistor, or IGBT for short. For example, the power semiconductor device involved in the embodiments of the present application may also be other devices with heat dissipation.

[0086] In some embodiments, as shown in FIG. 2 to FIG. 21 , the photovoltaic inverter 20 further includes a heat sink 230 , which is used to dissipate heat from each power semiconductor device.

[0087] In some embodiments, the radiator 230 includes an evaporator 231 and a condenser 232. The evaporator 231 is connected to the condenser 232 via a two-phase pipeline and contacts the outer wall of the lower housing 211. The condenser 232 is accommodated in the accommodating cavity of the upper housing 212. Because the condenser 232 and the evaporator 231 are arranged along a first direction (or the direction of gravity), the refrigerant in the evaporator 231 can be vaporized and enter the condenser 232 without the need for a pump or other power device. The refrigerant condensed into a liquid state by the condenser 232 flows back to the evaporator 231 under the action of gravity, thereby achieving efficient circulation of the refrigerant between the evaporator 231 and the evaporator 231.

[0088] In one embodiment, the radiator 230 includes an evaporator and two condensers. The evaporator is connected to each condenser via a two-phase pipeline and contacts the outer wall of the lower housing 211. Each condenser is housed in a sub-cavity of the upper housing 212. In this embodiment, the radiator 230 can be referred to as a one-to-two radiator 230. This allows all power semiconductor devices to share a single evaporator, allowing the heat dissipation capacity of the two condensers to be shared, reducing the cost of the radiator 230.

[0089] For example, as shown in FIG. 2 to FIG. 5 , FIG. 8 to FIG. 11 , FIG. 14 , FIG. 15 , FIG. 18 and FIG. 19 , the radiator 230 includes an evaporator 231 , a first condenser 232 a and a second condenser 232 b , and the evaporator 231 is connected to the first gas line L 11 , first liquid pipeline L 12 Connected to the first condenser 232a and through the second gas pipeline L 21 , Second liquid pipeline L 22 Connected to the second condenser 232b. In this way, the refrigerant in the evaporator 231 can absorb the heat generated by the power semiconductor device and evaporate into a gaseous state. The gaseous refrigerant is connected to the first gas pipeline L 11 Enter the first condenser 232a and pass through the second gas pipeline L 21 Enter the second condenser 232b. The outside air flows into each individual sub-cavity through a vent M1, and in the process of flowing in each individual sub-cavity, it takes away part of the heat of the first condenser 232a and the second condenser 232b, and flows out of each individual sub-cavity through another vent M2. In this way, the gaseous refrigerant in the first condenser 232a and the second condenser 232b will cool and condense into liquid refrigerant. Under the action of gravity, the first condenser 232a passes through the first liquid pipeline L 12Backflow to the evaporator 231, the second condenser 232b through the second liquid pipeline L 22 The solar energy flows back into the evaporator 231 to dissipate heat for the power semiconductor devices of the photovoltaic inverter 20 .

[0090] In another embodiment, the radiator 230 includes two evaporators and two condensers. Each evaporator is connected to a condenser via two-phase piping and is also connected to the outer wall of the lower housing 211. Each condenser is housed in a sub-chamber of the upper housing 212. In this embodiment, the evaporators and condensers in the radiator 230 are arranged one-to-one. This simplifies the assembly process between the evaporators and condensers and reduces costs.

[0091] For example, as shown in Figures 6, 7, 12, 13, 16, 17, 20 and 21, the radiator 230 includes a first evaporator 231a, a second evaporator 231b, a first condenser 232a and a second condenser 232b. The first evaporator 231a is connected to the first gas pipeline L 11 , first liquid pipeline L 12 Connected to the first condenser 232a, the second evaporator 231b is connected to the second gas pipeline L 21 , Second liquid pipeline L 22 Connected to the second condenser 232b. In this way, the refrigerants in the first evaporator 231a and the second evaporator 231b can absorb the heat generated by the power semiconductor device and evaporate into gas. The gaseous refrigerant in the first evaporator 231a is discharged through the first gas pipeline L 11 Entering the first condenser 232a, the gaseous refrigerant in the second evaporator 231b passes through the second gas pipeline L 21 Enter the second condenser 232b. The outside air flows into each individual sub-cavity through a vent M1, and in the process of flowing in each individual sub-cavity, it takes away part of the heat of the first condenser 232a and the second condenser 232b, and flows out of each individual sub-cavity through another vent M2. In this way, the gaseous refrigerant in the first condenser 232a and the second condenser 232b will cool and condense into liquid refrigerant. Under the action of gravity, the first condenser 232a passes through the first liquid pipeline L 12 The liquid flows back to the first evaporator 231a and the second condenser 232b through the second liquid pipeline L 22 The solar energy flows back into the second evaporator 231 b to dissipate heat for the power semiconductor devices of the photovoltaic inverter 20 .

[0092] The evaporator 231 and the power semiconductor device 222 are thermally connected. For example, at least one through-hole is provided on the front panel of the lower housing 211. Each through-hole extends through the front panel along a third direction between the front panel and the circuit board 221. Each through-hole is configured to accommodate a power semiconductor device 222. Furthermore, the evaporator 231 contacts the outer wall of the front panel connected to the lower housing 211. This allows heat generated by the power semiconductor device 222 to be directly transferred to the evaporator 231, reducing the heat conduction path from the power semiconductor device 222 to the evaporator 231 and improving the efficiency of heat transfer from the power semiconductor device 222 to the evaporator 231.

[0093] Furthermore, in some embodiments, along the third direction, the projection of each through hole on the front plate is located within the projection of the evaporator 231. Furthermore, a seal is provided around the area where the evaporator 231 contacts the outer wall of the front plate. This provides a high degree of sealing for the lower housing 211.

[0094] The two condensers are arranged at intervals along the second direction. For example, as shown in FIG2 to FIG21 , the first condenser 232 a and the second condenser 232 b are arranged at intervals along the second direction.

[0095] In some embodiments, each condenser has the same specifications.

[0096] In one embodiment, along the arrangement direction of the two substrates, the size of each condenser is equal to the maximum size of the sub-cavity that accommodates it. This eliminates the need to install fixtures in each sub-cavity to secure each condenser, reducing the production cost of the photovoltaic inverter 20.

[0097] For example, if the two substrates are spaced apart along the first direction, the dimension of the first condenser 232a along the first direction is equal to the distance between the first substrate 21251 and the upper side plate 2122, and the dimension of the second condenser 232b along the first direction is equal to the distance between the second substrate 21252 and the lower side plate 2121. For another example, if the two substrates are spaced apart along the third direction, the dimension of the first condenser 232a along the third direction is equal to the distance between the first substrate 21251 and the rear side plate 2124, and the dimension of the second condenser 232b along the third direction is equal to the distance between the second substrate 21252 and the front side plate 2123.

[0098] In another embodiment, along the arrangement direction of the two substrates, the dimensions of each condenser are smaller than the maximum dimensions of the sub-cavity housing it. The photovoltaic inverter 20 further includes two fixing members (or brackets), each of which is used to secure a condenser to a corresponding sub-cavity. Thus, the fixing members (or brackets) secure each condenser, preventing each condenser from shaking within its corresponding sub-cavity.

[0099] For example, as shown in Figures 2 to 12 , the dimension of the first condenser 232a along the first direction is smaller than the distance between the first substrate 21251 and the upper side plate 2122, and the dimension of the second condenser 232b along the first direction is smaller than the distance between the second substrate 21252 and the lower side plate 2121. For another example, as shown in Figures 14 to 20 , the dimension of the first condenser 232a along the third direction is smaller than the distance between the first substrate 21251 and the rear side plate 2124, and the dimension of the second condenser 232b along the third direction is smaller than the distance between the second substrate 21252 and the front side plate 2123.

[0100] In some embodiments, along the arrangement direction of the two substrates, the projection of each substrate overlaps with the projection of one condenser.

[0101] For example, as shown in Figures 2 to 13, the first substrate 21251 and the second substrate 21252 are arranged along a first direction. The projection of the first substrate 21251 along the first direction overlaps with the projection of the first condenser 232a, and the projection of the second substrate 21252 along the first direction overlaps with the projection of the second condenser 232b. In other words, the first condenser 232a is located above the first substrate 21251 along the first direction, and the second condenser 232b is located below the second substrate 21252 along the first direction.

[0102] For another example, as shown in Figures 14 to 21, the first substrate 21251 and the second substrate 21252 are arranged along the third direction. The projection of the first substrate 21251 along the third direction overlaps with the projection of the first condenser 232a, and the projection of the second substrate 21252 along the third direction overlaps with the projection of the second condenser 232b. In other words, the first condenser 232a is located behind the first substrate 21251 along the third direction, and the second condenser 232b is located in front of the second substrate 21252 along the first direction.

[0103] In some embodiments, as shown in Figures 4, 5, 10, and 11, when the radiator 230 includes an evaporator and two condensers, and the two substrates are spaced apart along the first direction, the distance between the first condenser 232a and the upper side plate 2122 is smaller than the distance between the second condenser 232b and the upper side plate 2122. Since the flow resistance of the gas is related to the height, when the two sub-cavities are distributed along the first direction, the height of the condenser in the upper sub-cavity is set higher than the height of the condenser in the lower sub-cavity. In this way, for the one-to-two radiator 230, it is possible to avoid uneven amounts of gaseous refrigerant in the evaporator entering the two condensers due to the height difference between the two sub-cavities, thereby avoiding uneven distribution of heat that needs to be dissipated by the two condensers.

[0104] In some embodiments, the photovoltaic inverter 20 further includes a plurality of fans, each of which is arranged between the lower side plate 2121 and the upper side plate 2122, that is, each fan is located in the cavity of the upper box 212. In this way, the fans can accelerate the circulation speed of air in the cavity of the upper box 212.

[0105] The multiple fans are divided into two groups, each fan group includes at least one fan, an air inlet of each fan faces a vent, and an air outlet of each fan group faces a condenser.

[0106] In one embodiment, each fan group is disposed in a sub-cavity, that is, each fan group is configured to accommodate a sub-cavity. Within each sub-cavity, the fans and condensers are arranged sequentially along the second direction, with the air inlet of each fan within each sub-cavity facing one vent and the air outlet facing another vent. Thus, each sub-cavity forms an air duct, and the flow of air within each sub-cavity cools the gaseous refrigerant within the condenser within each sub-cavity.

[0107] For example, as shown in Figures 2 to 13, along the first direction, the upper sub-chamber houses the first fan group, which includes four fans 240. Along the second direction, the first fan group and the first condenser 232a are arranged sequentially. Furthermore, the lower sub-chamber houses the second fan group, which in Figures 2 to 7 includes four fans 241, and in Figures 8, 10, and 13 includes two fans 241. As shown in Figures 2 to 13, along the second direction, the second fan group and the second condenser 232b are arranged sequentially. Each fan's air inlet faces one vent M1, and its air outlet faces another vent M2.

[0108] For another example, as shown in Figures 14 to 21, along the third direction, the rear sub-chamber houses a first set of fans, which includes four fans 240. Along the second direction, the first set of fans and the first condenser 232a are arranged sequentially. Furthermore, the front sub-chamber houses a second set of fans. The second set of fans in Figures 14 to 17 includes four fans 241, and the second set of fans in Figures 18 and 20 includes two fans 241. As shown in Figures 14 to 21, the second set of fans and the second condenser 232b are arranged sequentially along the second direction. Each fan's air inlet faces one vent M1, and its air outlet faces another vent M2.

[0109] In another embodiment, both sets of fans are uniformly positioned near a single vent. For example, as shown in Figures 8 to 13 and Figures 18 to 21, the distance between each fan and one vent M1 is smaller than the distance between each fan and the other vent M2, and the distance between each fan and the vent M1 is equal. Thus, positioning each fan near one of the two vents M1 not only ensures that air within the cavity of the upper housing 212 flows from one vent M1 to the other vent M2, but also simplifies the fan assembly process.

[0110] Furthermore, in one example, each fan group is fixed to one of two opposite side surfaces of the first substrate 21251 along the direction in which the two substrates are arranged. For example, if the two substrates are arranged in a first direction with an interval, the first fan group is fixed to the side of the first substrate 21251 facing the upper side plate 2122, and the second fan group is fixed to the side of the first substrate 21251 facing the lower side plate 2121. For another example, if the two substrates are arranged in a third direction with an interval, the first fan group is fixed to the side of the first substrate 21251 facing the rear side plate 2124, and the second fan group is fixed to the side of the first substrate 21251 facing the front side plate 2123.

[0111] Furthermore, in another example, one group of fans is fixed to the surface of the upper side plate 2122 facing the middle partition plate 2125, and the other group of fans is fixed to the surface of the lower side plate 2121 facing the middle partition plate 2125. For example, the first group of fans is fixed to the side of the upper side plate 2122 facing the middle partition plate 2125, and the second group of fans is fixed to the side of the lower side plate 2121 facing the middle partition plate 2125.

[0112] Furthermore, in another example, both sets of fans are fixed to the first fixing plate 2126. In this example, the size of the first fixing plate 2126 along the first direction is larger than the distance between the upper plate 2122 and the first base plate 21251, and there is a gap between the first fixing plate 2126 and the first base plate 21251 along the second direction.

[0113] In another embodiment, the distance between each group of fans and the condenser in the corresponding sub-cavity is within a certain range. For example, as shown in Figures 2 to 7 and Figures 14 to 17, the distance between the first group of fans and the first condenser 232a is within a certain range, and the distance between the second group of fans and the second condenser 232b is within a certain range. In this way, the wind on the air outlet side of each group of fans can diffuse in the corresponding sub-cavity, making the wind in the corresponding sub-cavity more uniform, and then the wind in each sub-cavity can evenly cool the gaseous refrigerant in the condenser. Among them, the distance range between each group of fans and the condenser in the corresponding sub-cavity can be set according to historical experience values.

[0114] Furthermore, in one example, one group of fans is fixed to one of two opposite side surfaces of the first substrate 21251 along the direction in which the two substrates are arranged, and the other group of fans is fixed to one of two opposite side surfaces of the second substrate 21252 along the direction in which the two substrates are arranged. For example, if the two substrates are spaced apart along a first direction, the first group of fans is fixed to the side of the first substrate 21251 facing the upper side panel 2122, and the second group of fans is fixed to the side of the second substrate 21252 facing the lower side panel 2121. For another example, if the two substrates are spaced apart along a third direction, the first group of fans is fixed to the side of the first substrate 21251 facing the rear side panel 2124, and the second group of fans is fixed to the side of the second substrate 21252 facing the front side panel 2123.

[0115] Furthermore, in another example, one group of fans is fixed to the surface of the upper side plate 2122 facing the middle partition plate 2125, and the other group of fans is fixed to the surface of the lower side plate 2121 facing the middle partition plate 2125. For example, the first group of fans is fixed to the side of the upper side plate 2122 facing the middle partition plate 2125, and the second group of fans is fixed to the side of the lower side plate 2121 facing the middle partition plate 2125.

[0116] Furthermore, in another example, one set of fans is fixed to the first fixing plate 2126, and another set of fans is fixed to the second fixing plate 2127. In this example, the size of the first fixing plate 2126 along the first direction can be equal to the distance between the upper plate 2122 and the first base plate 21251.

[0117] In some embodiments, the projection of each fan in each sub-chamber along the second direction overlaps with the projection of the condenser in each sub-chamber. In this way, the air from the air outlet side of each set of fans can quickly cool the gaseous refrigerant in the condenser, thereby improving the cooling efficiency of the gaseous refrigerant in the condenser.

[0118] In some embodiments, in order to enable the photovoltaic power generation system to support DC-coupled energy storage and reduce the cost of AC cables, multiple photovoltaic inverters 20 can be integrated together and housed in a photovoltaic inverter container. For example, as shown in Figure 22, the multiple photovoltaic inverters 20 of the photovoltaic inverter container 200 are divided into two groups, and the two groups of photovoltaic inverters are arranged at intervals along the second direction. Each group of photovoltaic inverters includes at least one photovoltaic inverter 20, and the multiple photovoltaic inverters 20 of each group of photovoltaic inverters are arranged along the third direction. There is a gap between each group of photovoltaic inverters and the top plate of the photovoltaic inverter container 200. In this way, the heat-carrying air flowing out of the upper box 212 of each photovoltaic inverter 20 can be dissipated to the outside through the gap between the upper box 212 and the top plate of the photovoltaic inverter container 200.

[0119] Furthermore, in some embodiments, the photovoltaic inverter container equipment 200 also includes at least one distribution cabinet, such as the first distribution cabinet 250a and the second distribution cabinet 250b shown in Figure 22, each distribution cabinet is accommodated in the accommodating cavity of the photovoltaic inverter container equipment 200, and each distribution cabinet is used to control and distribute power to each photovoltaic inverter.

[0120] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A photovoltaic inverter, characterized in that: The photovoltaic inverter comprises: at least one power semiconductor device; A lower box body, used for accommodating the power semiconductor device; A radiator, comprising two condensers and at least one evaporator, wherein the evaporator is used to: connect the condensers with two-phase pipelines, contact and connect the outer wall of the lower box, and conduct heat to connect the power semiconductor device; An upper box body, wherein the upper box body and the lower box body are arranged along a first direction, wherein the upper box body comprises a middle partition and two vents arranged opposite to each other along a second direction, wherein the middle partition is a stepped structure along the second direction, wherein the middle partition is used to separate the cavity of the upper box body into two sub-cavities, wherein each sub-cavity is used to accommodate one condenser, and wherein the two condensers are arranged at intervals along the second direction.

2. The photovoltaic inverter according to claim 1, characterized in that: The middle partition includes three partitions, two of which are arranged at intervals along the first direction and the projections of the two partitions along the first direction do not overlap, or two of which are arranged at intervals along the third direction and the projections of the two partitions along the third direction do not overlap, and another partition is used to connect the two partitions, wherein: Along the arrangement direction of the two partitions, the projection of each partition overlaps with the projection of one condenser.

3. The photovoltaic inverter according to claim 2, characterized in that: The upper box body includes two side panels arranged opposite to each other along the first direction, and the two partitions are respectively arranged opposite to the two side panels along the first direction, and the distance between one of the two partitions and one of the two side panels is equal to the distance between the other of the two partitions and the other of the two side panels.

4. The photovoltaic inverter according to claim 3, characterized in that: The number of the evaporator is one, and the distance between one of the two condensers and the one side plate is smaller than the distance between the other condenser and the one side plate.

5. The photovoltaic inverter according to claim 2, characterized in that: The upper box body includes two other side panels arranged relatively to each other along the third direction, and the two partitions are respectively arranged relatively to the other two side panels along the third direction, and the distance between one of the two partitions and one of the other two side panels is equal to the distance between the other of the two partitions and the other of the other two side panels.

6. The photovoltaic inverter according to any one of claims 1 to 5, characterized in that: The photovoltaic inverter further includes two groups of fans, each group of fans includes at least one fan, an air inlet of each of the fans faces one of the vents, and an air outlet of each group of fans faces one of the condensers.

7. The photovoltaic inverter according to claim 6, characterized in that: The distance between each of the fans and one of the vents is smaller than the distance between each of the fans and another of the vents; Each of the fans is equidistant from the one vent.

8. The photovoltaic inverter according to claim 6 or 7, characterized in that: A projection of each of the fans in each of the sub-cavities along the second direction overlaps with a projection of the condenser in each of the sub-cavities.

9. The photovoltaic inverter according to any one of claims 1 to 8, characterized in that: The number of the evaporators is two, and each evaporator is used for connecting one condenser via a two-phase pipeline.

10. A photovoltaic power generation system, characterized in that: It comprises a photovoltaic component and a photovoltaic inverter as described in any one of claims 1 to 9, wherein the photovoltaic component is used to convert light energy into electrical energy, and the photovoltaic inverter is used to convert direct current from the photovoltaic component into alternating current.

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