An isolated grid-connected inverter and photovoltaic power generation system

Abstract

The application relates to the technical field of inverters, in particular to an isolated grid-connected inverter and a photovoltaic power generation system, which solve the problem that the grid-connected inverter is large in size and cannot be applied to a photovoltaic building integrated power generation system, the grid-connected inverter comprises a box body, a split type heat dissipation device, a first passive device, a filter and a first active device; the split type heat dissipation device is arranged on the bottom plate of the box body, so as to divide the box body into multiple cavities, the first passive device, the filter and the first active device are distributed in the multiple cavities, and the photovoltaic power generation system comprises the grid-connected inverter; the inverter is compact in structure, does not waste internal space, reduces the volume, thickness and weight of the grid-connected inverter, and is more in contact with the heating elements for heat dissipation through the split type heat dissipation device, so that the utilization rate of the heat radiator is improved, and the heat dissipation effect of the grid-connected inverter is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inverters, in particular to an isolated grid-connected inverter and a photovoltaic power generation system. BACKGROUND

[0002] The photovoltaic power generation system refers to a power generation system directly converting light energy into electric energy without a thermal process. The main components of the photovoltaic power generation system are solar cells, storage batteries, controllers and inverters. The photovoltaic power generation system has the characteristics of high reliability, long service life, no pollution to the environment and the ability to independently generate electricity and operate in parallel. The photovoltaic building integrated power generation system integrates the photovoltaic power generation system into a building. The system does not require additional ground space and is the best way to apply renewable energy power generation in cities.

[0003] In the main components of the photovoltaic building integrated power generation system, thin-film solar cells have become the mainstream choice for the photovoltaic building integrated power generation system because they have the advantages of being bendable, high light transmittance and less environmental pollution compared to crystalline silicon solar cells. As an essential part of the photovoltaic building integrated power generation system, the grid-connected inverter has higher requirements for the size, weight and operating temperature of the grid-connected inverter compared to the roof distributed photovoltaic power generation system.

[0004] In order to reduce unnecessary connection cables, the grid-connected inverter is usually placed on the backboard of the thin-film solar photovoltaic module, which requires the size of the grid-connected inverter to be smaller than a single photovoltaic panel and the height of the grid-connected inverter to be smaller than the distance between the photovoltaic module and the building outer wall, usually less than 10 cm. Therefore, the structure and heat resistance of the grid-connected inverter are also highly required.

[0005] The traditional grid-connected inverter usually adopts an integrated heat dissipation design. A large heat sink is arranged on the bottom plate inside the grid-connected inverter, and power devices or power modules are arranged on the upper surface close to the heat sink. Although this heat dissipation method has good effect, it wastes a large amount of space inside the grid-connected inverter, resulting in a large size of the grid-connected inverter, which is not suitable for the photovoltaic building integrated power generation system, especially the building outer wall photovoltaic power generation system. In order to avoid the PID effect of the thin-film solar cell, the negative electrode of the thin-film solar cell needs to be grounded, so the grid-connected inverter needs to include an isolated transformer element, which makes it impossible to reduce the size of the traditional grid-connected inverter and apply it to the building outer wall photovoltaic power generation system.

[0006] Therefore, the present application proposes an isolated grid-connected inverter with a smaller size and better heat dissipation effect, and a photovoltaic power generation system comprising the isolated grid-connected inverter. SUMMARY

[0007] The present application aims at the above-mentioned problems, and provides an isolated grid-connected inverter and a photovoltaic power generation system.

[0008] The technical scheme adopted by the present application is as follows:

[0009] To achieve the above-mentioned purposes, in a first aspect, the present application provides an isolated grid-connected inverter, comprising a box body, a split heat dissipation device, a first passive device, a filter and a first active device.

[0010] The split heat dissipation device is arranged on the bottom plate of the box body to separate the box body into multiple cavities, and the first passive device, the filter and the first active device are distributed in the multiple cavities.

[0011] According to the embodiment of the present application, optionally, in the above-mentioned isolated grid-connected inverter, the bottom plate of the box body is provided with multiple fixing grooves, and the split heat dissipation device is arranged in the fixing grooves to separate the box body into multiple separated cavities.

[0012] According to the embodiment of the present application, optionally, in the above-mentioned isolated grid-connected inverter, the split heat dissipation device comprises at least two heat sinks, and the box body comprises at least three cavities separated by the at least two heat sinks.

[0013] According to the embodiment of the present application, optionally, in the above-mentioned isolated grid-connected inverter, the first passive device comprises a transformer, the filter comprises an input EMI filter and an output EMI filter, and the first active device comprises an inductor.

[0014] According to the embodiment of the present application, optionally, in the above-mentioned isolated grid-connected inverter, the box body comprises a first cavity, a second cavity and a third cavity separated by the split heat dissipation device.

[0015] The inductor comprises a BOOST inductor, a resonance inductor and an AC filter inductor.

[0016] The input EMI filter and the BOOST inductor are arranged in the first cavity, the transformer and the resonance inductor are arranged in the second cavity, and the output EMI filter and the AC filter inductor are arranged in the third cavity.

[0017] According to the embodiment of the present application, optionally, in the above-mentioned isolated grid-connected inverter, the first cavity is further provided with an input board, and the input EMI filter and the input terminal are arranged on the input board; the third cavity is further provided with an output board, and the output EMI filter and the output terminal are arranged on the output board.

[0018] According to the embodiment of the present application, optionally, in the above-mentioned isolated grid-connected inverter, the inverter further comprises a power board, the split heat dissipation device is located at the middle lower part of the box, and the height of the upper surface of the split heat dissipation device is lower than the height of the upper surface of the box, so that the top surface of the split heat dissipation device is in contact with the power board.

[0019] According to the embodiment of the present application, optionally, in the above-mentioned isolated grid-connected inverter, the power board is provided with a power supply, a second passive device and a second active device, the second passive device comprises a BOOST capacitor, an absorption capacitor and a bus capacitor, and the second active device comprises a MOS tube.

[0020] The power supply, the BOOST capacitor and the absorption capacitor are arranged on the upper surface of the power board, the bus capacitor and the MOS tube are arranged on the lower surface of the power board, the bus capacitor is located in the cavity, and the MOS tube is in contact with the side surface of the split heat dissipation device.

[0021] According to the embodiment of the present application, optionally, in the above-mentioned isolated grid-connected inverter, the inverter further comprises a driving circuit and a control circuit, and the driving circuit and the control circuit are arranged at the upper part of the box.

[0022] According to the embodiment of the present application, optionally, in the above-mentioned isolated grid-connected inverter, the first passive device and the first active device are placed at one end in the box and are in contact with one end of the split heat dissipation device.

[0023] According to the embodiment of the present application, optionally, in the above-mentioned isolated grid-connected inverter, the inverter further comprises a fan, one end of the split heat dissipation device is provided with an opening, the fan is arranged on the outer surface of the other end of the box opposite to the one end in the box, and the other end of the split heat dissipation device opposite to the one end is connected.

[0024] In the second aspect, the present application provides a photovoltaic power generation system comprising the above-mentioned isolated grid-connected inverter.

[0025] Compared with the prior art, one or more embodiments in the above-mentioned scheme can have the following advantages or beneficial effects:

[0026] 1.The isolated grid-connected inverter and photovoltaic power generation system provided by the present application, by setting a split heat dissipation device on the bottom plate of the box to separate the box into multiple cavities, setting the first passive device, filter and first active device in the cavities, the horizontal arrangement of the heat generating elements and heat sink is realized, through the above setting, the problem that the existing grid-connected inverter is too large to be applied to the photovoltaic building integrated power generation system is solved; the grid-connected inverter of the present application is compact in structure, does not waste the internal space of the grid-connected inverter, greatly reduces the volume, thickness and weight of the grid-connected inverter, and, through the split heat dissipation device and the heat generating elements, more contact for heat dissipation, the utilization rate of the heat sink is improved, thereby improving the heat dissipation effect of the grid-connected inverter.

[0027] 2.In the present application, the split heat dissipation device includes at least two heat sinks, and the box includes at least three cavities separated by the at least two heat sinks, the number of heat sinks and the size of the box can be reasonably set according to the size, volume and heat generated by the heat generating elements in actual application, to balance the heat dissipation performance and volume of the inverter to the maximum, for building outer wall photovoltaic power generation system.

[0028] 3.In the present application, the inverter further includes a power board, the split heat dissipation device is located in the middle and lower part of the box, and the height of the upper surface of the split heat dissipation device is lower than the height of the upper surface of the box, so that the top surface of the split heat dissipation device is in contact with the power board, the power board is arranged above the heat sink, the split heat dissipation device contacts the heat generating elements from three sides, which realizes the reduction of the volume of the inverter while improving the heat dissipation effect of the inverter.

[0029] 4.In the present application, the power supply, the BOOST capacitor and the absorption capacitor are all arranged on the upper surface of the power board, the bus capacitor and the MOS tube are all arranged on the lower surface of the power board, the bus capacitor is located in the cavity, and the MOS tube is in contact with the side surface of the split heat dissipation device, which fully utilizes the relative spatial position of the cavity, improves the utilization rate of the internal space of the grid-connected inverter, further reduces the overall size of the grid-connected inverter, and thus reduces the installation cost of the photovoltaic power generation system.

[0030] 5.In the present application, the first passive device and the first active device are both placed at one end in the box, and are in contact with one end of the split heat dissipation device, when the grid-connected inverter needs to be placed vertically, the first passive device and the first active device which generate a lot of heat will be located at the upper end in the vertically placed box, which can prevent the heat generated by themselves from affecting other heat generating elements. BRIEF DESCRIPTION OF DRAWINGS

[0031] In the following, the present application will be described in more detail on the basis of embodiments and with reference to the accompanying drawings.

[0032] Figure 1 A structure schematic diagram of an isolated grid-connected inverter provided by the embodiment one of the present application.

[0033] Figure 2 A structure schematic diagram of a box of an isolated grid-connected inverter provided by the embodiment one of the present application.

[0034] Figure 3 A schematic diagram of arrangement in a box of an isolated grid-connected inverter provided by the embodiment one of the present application.

[0035] Figure 4 A top view of a structure schematic diagram of an isolated grid-connected inverter provided by the embodiment one of the present application.

[0036] Figure 5 A structure schematic diagram of a power board of an isolated grid-connected inverter provided by the embodiment one of the present application.

[0037] In the figure, 1. box, 101. first cavity, 102. second cavity, 103. third cavity, 104. fixed groove, 2. radiator, 3. transformer, 401. input board, 402. BOOST inductor, 403. resonance inductor, 404. AC filter inductor, 405. output board, 5. power board, 501. power supply, 502. BOOST capacitor, 503. absorption capacitor, 504. bus capacitor, 505. MOS tube, 6. fan.

[0038] In the attached drawings, the same components use the same reference numerals, and the drawings are not drawn according to the actual scale. DETAILED DESCRIPTION

[0039] The embodiments of the present application will be described in detail below with reference to the accompanying drawings and embodiments, so that the implementation process of how the present application applies technical means to solve technical problems and achieves corresponding technical effects can be fully understood and implemented. The embodiments of the present application and each feature in the embodiments can be combined with each other without conflict, and the formed technical solutions are within the protection scope of the present application.

[0040] Example One

[0041] Please refer to Figures 1 to 5 , the embodiment provides an isolated grid-connected inverter, as Figure 1 shown, the inverter comprises a box 1, a split radiator, a first passive device, a filter, a first active device, a power board 5 and a fan.

[0042] The split radiator is arranged on the bottom plate of the box 1 to divide the box 1 into multiple cavities.

[0043] As Figure 2 shown, the bottom plate of the box 1 is provided with a plurality of fixing grooves 104, which are U-shaped in the box and have openings at both ends connected to the both ends of the box 1. The split heat sink is arranged in the fixing groove 104, and the box 1 is separated into a plurality of separated cavities. In this embodiment, the box 1 is made of an aluminum alloy plate with a thickness of 2 mm, and the bottom plate of the box 1 is provided with two fixing grooves 104.

[0044] As Figure 3 shown, the split heat sink includes at least two heat sinks 2, and the box 1 includes at least three cavities separated by the at least two heat sinks 2. In this embodiment, the split heat sink includes two heat sinks 2 arranged in the two fixing grooves 104, and the box 1 is separated into three separated cavities. The number of heat sinks and the size of the box can be reasonably set according to the size, volume and heat generated by the heating element in actual application, so as to balance the heat dissipation performance and volume of the inverter to the maximum, and to be used for building outer wall photovoltaic power generation system.

[0045] Further, the first passive device, the filter and the first active device are distributed in a plurality of cavities; the first passive device includes a transformer 3, the filter includes an input EMI filter and an output EMI filter, and the first active device includes an inductor.

[0046] Further, the box 1 includes a first cavity 101, a second cavity 102 and a third cavity 103 separated by the split heat sink;

[0047] The inductor includes a BOOST inductor 402, a resonance inductor 403 and an AC filter inductor 404;

[0048] The input EMI filter and the BOOST inductor 402 are placed in the first cavity 101, the BOOST inductor 402 is fixed on the bottom plate of the box 1 by an inductor clip, and the first cavity 101 is further provided with an input plate 401, the input EMI filter and an input terminal are arranged on the input plate 401, the input terminal is connected to the output terminal of the solar cell module, and the received electrical energy enters the DC-DC level converter of the inverter after being filtered by the input EMI filter. The DC-DC level of the inverter tracks the maximum power output point of the solar cell module, and at the same time, the voltage is lifted to a higher level. The optional topology includes boost, three-level boost, etc.

[0049] The transformer 3 and the resonant inductor 403 are placed in the second cavity 102, the outer surface of the transformer 3 is sequentially provided with heat dissipation silica gel and a heat dissipation shell, the heat dissipation silica gel and the heat dissipation shell are used for heat dissipation, the transformer 3 is close to the resonant inductor 403, the transformer 3 is a high-frequency direct-current transformer, and isolation between a photovoltaic side and a power grid side is realized, and optional topologies include LLC, DAB, and a phase-shifted full-bridge.

[0050] The output EMI filter and the AC filter inductor 404 are placed in the third cavity 103, the AC filter inductor 404 is fixed on the bottom plate of the cabinet 1 through an inductor clamp, the third cavity 103 is further provided with an output plate 405, the output EMI filter and an output terminal are arranged on the output plate 405, direct-current voltage isolated by the transformer 3 enters a DC-AC converter of an inverter, the DC-AC stage of the inverter converts direct-current voltage converted by solar energy into alternating-current voltage, the alternating-current voltage is filtered through the output EMI filter, and then is input into the power grid through the output terminal, and the filter can effectively avoid interference of a switching power supply on the power grid.

[0051] Further, the split heat dissipation device is located at the middle and lower part of the cabinet 1, and the height of the upper surface of the split heat dissipation device is lower than the height of the upper surface of the cabinet 1, so that the top surface of the split heat dissipation device is in contact with the power plate 5, the power plate is arranged above the heat dissipation device, three surfaces of the split heat dissipation device are in contact with heat generating elements for heat dissipation, and the volume of the inverter is reduced while the heat dissipation effect of the inverter is improved.

[0052] As shown in Figure 4 The power plate 5 is provided with a power supply 501, second passive devices and second active devices, the second passive devices include a BOOST capacitor 502, an absorption capacitor 503 and a bus capacitor 504, and the second active devices include a MOS tube 505; the power plate 5 is a U-shaped plate and includes a horizontal plate and two side plates, the horizontal plate of the power plate 5 is located above the second cavity 102, the two side plates of the power plate 5 are respectively located on the upper surfaces of the heat dissipation devices (2), and the power plate 5 does not block the BOOST inductor 402, the transformer 3, the resonant inductor 403 and the AC filter inductor 404, so that the above-mentioned heat generating elements can be better heat dissipated;

[0053] As shown in Figure 5As shown, the power supply 501, the BOOST capacitor 502 and the absorption capacitor 503 are arranged on the upper surface of the power plate 5, the power supply 501 and the BOOST capacitor 502 are arranged on the left side plate of the power plate 5, above the input plate 401 of the first cavity 101, and the absorption capacitor 503 is arranged on the upper surface of the two side plates of the power plate 5.

[0054] The bus capacitor 504 and the MOS tube 505 are arranged on the lower surface of the power plate 5, the bus capacitor 504 is arranged in the cavity, at the other end of the cabinet 1 opposite to the transformer 3 arranged in the cabinet 1, is welded to the lower surface of the horizontal plate of the power plate 5, is inverted in the second cavity 102, and the MOS tube 505 is arranged on the lower surface of the two side plates of the power plate 5, is arranged opposite to the absorption capacitor 503, and just contacts the side surface of the split heat sink, fully utilizes the relative spatial position of the cavity, improves the utilization rate of the internal space of the grid-connected inverter, further reduces the overall size of the grid-connected inverter, and thus reduces the installation cost of the photovoltaic power generation system.

[0055] Further, the inverter further comprises a driving circuit and a control circuit, and the driving circuit and the control circuit are arranged on the upper part of the cabinet 1 and can be arranged on the power plate 5 in the embodiment.

[0056] Further, the first passive device and the first active device are arranged at one end in the cabinet 1 and contact one end of the split heat sink, one end of the split heat sink is provided with an opening, the fan 6 is arranged on the outer surface of the other end of the cabinet 1 opposite to the one end in the cabinet 1 and is connected to the other end opposite to the one end of the split heat sink, when the grid-connected inverter for the building outer wall photovoltaic power generation system needs to be vertically placed, the first passive device and the first active device which generate a large amount of heat are located at the upper end in the vertically placed cabinet, so that the heat generated by the first passive device and the first active device can not affect other heat generating elements.

[0057] The grid-connected inverter provided in the embodiment separates the cabinet into multiple cavities through the split heat sink arranged on the bottom plate of the cabinet, arranges the first passive device, the filter and the first active device in the cavities, realizes the horizontal arrangement of the heat generating elements and the heat sink, solves the problem that the existing grid-connected inverter has a large size and cannot be applied to the photovoltaic building integrated power generation system through the above arrangement, the grid-connected inverter has a compact structure, does not waste the internal space of the grid-connected inverter, greatly reduces the size, thickness and weight of the grid-connected inverter, and the heat sink has more contact with the heat generating elements for heat dissipation, improves the utilization rate of the heat sink, and thus improves the heat dissipation effect of the grid-connected inverter.

[0058] Example Two

[0059] The embodiment provides a photovoltaic power generation system based on the embodiment one, comprising the isolation type grid-connected inverter as described in the embodiment one, and the thickness of the isolation type grid-connected inverter can be set according to actual requirements, and the specific setting can be referred to the embodiment one, which will not be repeated here.

[0060] The photovoltaic power generation system provided by the embodiment can be applied to the outer wall of a building and also can be applied to a roof building. When used for the outer wall of a building, the isolation type grid-connected inverter is arranged between the solar photovoltaic module and the outer wall of the building. The direct current generated by the solar cell module is converted into alternating current meeting the requirements of the power grid through the grid-connected inverter and then directly connected to the public power grid. The photovoltaic power generation system has high reliability, long service life, no pollution to the environment and can independently generate power and also can operate in parallel with the grid.

[0061] In conclusion, the isolation type grid-connected inverter and the photovoltaic power generation system provided by the embodiment can separate the box into multiple cavities through the split type heat dissipation device arranged on the bottom plate of the box, and the first passive device, the filter and the first active device are arranged in the cavities, so that the horizontal arrangement of the heat generating elements and the heat sink is realized. Through the above arrangement, the problem that the existing grid-connected inverter has a large size and cannot be applied to the photovoltaic building integrated power generation system is solved. The grid-connected inverter has a compact structure, does not waste the internal space of the grid-connected inverter, greatly reduces the size, thickness and weight of the grid-connected inverter, and the utilization rate of the heat sink is improved through the split type heat dissipation device and the heat generating elements, so that the heat dissipation effect of the grid-connected inverter is improved. In use, the number of heat sinks and the size of the box can be reasonably set according to the size, volume and heat generated by the heat generating elements in actual application, so that the heat dissipation performance and the size of the inverter are balanced to the maximum extent for the photovoltaic power generation system for the outer wall of a building. The power board is arranged above the heat sink, so that the split type heat dissipation device contacts the heat generating elements from three sides, the size of the inverter is reduced, and the heat dissipation effect of the inverter is improved. The relative spatial positions of the cavities are fully utilized, the utilization rate of the internal space of the grid-connected inverter is improved, the overall size of the grid-connected inverter is further reduced, and the installation cost of the photovoltaic power generation system is reduced. When the grid-connected inverter needs to be placed vertically, the first passive device and the first active device which generate a large amount of heat are located at the upper end in the vertically placed box, so that the heat generated by the first passive device and the first active device can not affect other heat generating elements.

[0062] In the several embodiments of the present application, it should be understood that the disclosed system and method can be implemented in other ways. The system and method embodiments described above are only exemplary.

[0063] It should be noted that, in this document, the terms "comprising", "comprises" or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the recited element.

[0064] Although the embodiments of the present application have been disclosed with reference to the above embodiments, the above description is merely used to facilitate understanding of the present application and is not used to limit the present application. Any modification and change in the form and details of the present application can be made by any person skilled in the art without departing from the spirit and scope of the present application, and the patent protection scope of the present application should be subject to the scope defined by the appended claims.

Claims

1. An isolated grid-connected inverter, characterized in that, It includes a housing (1), a split heat dissipation device, a first passive device, a filter, a first active device, and a power board (5); The split-type heat dissipation device is disposed on the bottom plate of the housing (1) to divide the housing (1) into multiple cavities, and the first passive device, the filter and the first active device are distributed in the multiple cavities; The first passive device includes a transformer (3), and the outer surface of the transformer (3) is sequentially provided with thermal silicone and a heat sink; the filter includes an input EMI filter and an output EMI filter, and the first active device includes an inductor; The enclosure (1) includes a first cavity (101), a second cavity (102) and a third cavity (103) separated by the split heat dissipation device. The inductors include a BOOST inductor (402), a resonant inductor (403), and an AC filter inductor (404). The input EMI filter and the BOOST inductor (402) are placed in the first cavity (101), the transformer (3) and the resonant inductor (403) are placed in the second cavity (102), and the output EMI filter and the AC filter inductor (404) are placed in the third cavity (103). The split heat dissipation device is located in the lower middle part of the housing (1), and the height of the upper surface of the split heat dissipation device is lower than the height of the upper surface of the housing (1), so that the top surface of the split heat dissipation device contacts the power board (5).

2. The isolated grid-connected inverter according to claim 1, characterized in that, The bottom plate of the box (1) is provided with multiple fixing slots (104), and the split heat dissipation devices are respectively set in the fixing slots (104) to isolate the box (1) into multiple separate cavities.

3. The isolated grid-connected inverter according to claim 1, characterized in that, The split-type heat dissipation device includes at least two heat sinks (2), and the housing (1) includes at least three cavities separated by the at least two heat sinks (2).

4. The isolated grid-connected inverter according to claim 1, characterized in that, The first cavity (101) is also provided with an input board (401), and the input EMI filter and input terminal are disposed on the input board (401); the third cavity (103) is also provided with an output board (405), and the output EMI filter and output terminal are disposed on the output board (405).

5. The isolated grid-connected inverter according to claim 1, characterized in that, The power board (5) is provided with a power supply (501), a second passive device and a second active device. The second passive device includes a BOOST capacitor (502), an absorption capacitor (503) and a bus capacitor (504). The second active device includes a MOS transistor (505). The power supply (501), the BOOST capacitor (502), and the absorption capacitor (503) are all disposed on the upper surface of the power board (5), the bus capacitor (504) and the MOS transistor (505) are all disposed on the lower surface of the power board (5), the bus capacitor (504) is located in the cavity, and the MOS transistor (505) is in contact with the side of the split heat dissipation device.

6. The isolated grid-connected inverter according to claim 1, characterized in that, The inverter also includes a drive circuit and a control circuit, which are located on the upper part of the housing (1).

7. The isolated grid-connected inverter according to claim 1, characterized in that, Both the first passive device and the first active device are placed at one end inside the housing (1) and are in contact with one end of the split heat dissipation device.

8. The isolated grid-connected inverter according to claim 7, characterized in that, The inverter also includes a fan (6), one end of the split heat dissipation device is provided with an opening, the fan (6) is provided on the outer surface of the other end of the housing (1) opposite to one end inside the housing (1), and is connected to the other end opposite to one end of the split heat dissipation device.

9. A photovoltaic power generation system, characterized in that, Including the isolated grid-connected inverter as described in any one of claims 1 to 8.

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