Photovoltaic inverters

Abstract

Photovoltaic inverter, characterized in that it includes: a housing, wherein the housing is provided with a receiving chamber; and a printed circuit board assembly arranged in the receiving chamber, wherein the printed circuit board assembly comprises a first printed circuit board and a second printed circuit board arranged parallel to each other, and wherein high elements mounted on the first and second printed circuit boards are arranged on the opposite board surfaces of the first printed circuit board and / or the second printed circuit board.

Description

TECHNICAL AREA

[0001] The present application relates to the technical field of inverters, in particular to a photovoltaic inverter. STATE OF THE ART

[0002] Currently, most photovoltaic inverters use a front-mount circuit board design, where the components are mounted on one side of the board before it is installed in the housing. Due to limitations imposed by the number and height of the components, as well as additional structures such as heat sinks, the overall thickness of the photovoltaic inverter is considerable, making wall mounting very difficult. Furthermore, in conventional photovoltaic inverters, the switch and the PV terminal are connected by a cable, leading to problems with cumbersome installation procedures and internal EMC (electromagnetic compatibility) interference. REVELATION OF THE INVENTION

[0003] The present application provides a photovoltaic inverter to solve the problems of the excessive thickness of the photovoltaic inverter, the cumbersome assembly process and the presence of EMC interference caused by the use of cable connections for internal switches and PV terminals.

[0004] The present application provides a photovoltaic inverter which includes: a housing, wherein the housing is provided with a receiving chamber, and a printed circuit board assembly arranged in the receiving chamber, wherein the printed circuit board assembly comprises a first printed circuit board and a second printed circuit board arranged parallel to each other, and wherein high elements mounted on the first and second printed circuit boards are arranged on the opposite board surfaces of the first printed circuit board and / or the second printed circuit board.

[0005] The components mounted on the first and second printed circuit boards (PCBs) include tall and short elements. These tall and short elements are distinguished by their geometric height perpendicular to the surfaces of the first and second PCBs, where "tall" and "short" are relative terms. For example, the geometric height of a switch, in the direction perpendicular to the surfaces of the first and second PCBs, is greater than that of an SMD resistor, so the switch can be considered a tall element, while the SMD resistor is considered a short element.

[0006] It is understandable that if the tall elements are positioned between the first and second circuit boards, the distance between these boards is greater than the geometric height of other short elements. In such a case, the short elements can also be mounted between the first and second circuit boards. Therefore, by arranging two circuit boards (namely the first and second), the available space within the photovoltaic inverter housing can be fully utilized based on the different geometric heights of the tall and short elements. This allows for a hierarchical use of vertical space, thereby reducing the thickness of the inverter housing and the overall volume of the photovoltaic inverter.

[0007] In one possible embodiment, the housing comprises a lower housing and an upper cover, with part of the bottom surface of the lower housing projecting into the receiving chamber, thereby forming a projection that divides the receiving chamber into at least two sub-receiving chambers.

[0008] In one possible embodiment, the receiving chamber comprises a first receiving chamber and a second receiving chamber connected to each other, with the first printed circuit board being arranged in the first receiving chamber and the second printed circuit board covering an end of the first and second receiving chambers located near the top cover.

[0009] In one possible embodiment, a part of the second circuit board covering the first receiving chamber is provided with a recess, so that the front of the first circuit board is opposite the upper cover.

[0010] In one possible embodiment, a heat-generating component is mounted opposite the projection on the second circuit board, the surface of the projection being provided with a thermally conductive contact section through which the heat-generating component is connected to the projection.

[0011] In one possible embodiment, it is provided that a switch is also included, the switch being provided with pins that are inserted into the sockets on the conductive part of the first circuit board and thus firmly connected.

[0012] In one possible embodiment, it is provided that a PV terminal and a foil clamp are also included, wherein the first circuit board is equipped with a terminal connecting element, with one end of the foil clamp being connected to the PV terminal and the other end of the foil clamp being firmly connected to the terminal connecting element.

[0013] In one possible embodiment, the clamping connecting element is provided for as a surface-mounted nut and / or a saddle clamp.

[0014] In one possible embodiment, heat dissipation ribs are mounted on the bottom surface of the lower housing, with a groove formed on the outside of the bottom surface of the lower housing corresponding to the projection, and with the length of the heat dissipation ribs inside the groove exceeding the depth of the groove.

[0015] The photovoltaic inverter according to the present application uses a split circuit board design. By mounting a first and a second circuit board in opposite orientations, the components are positioned between the first and second circuit boards. This allows the entire receiving chamber within the photovoltaic inverter to be utilized, thus reducing its thickness. Furthermore, part of the bottom surface of the lower housing projects into the receiving chamber, forming a projection that divides the receiving chamber into at least two sub-receiving chambers.At the same time, the projection forms a groove on the outer surface of the lower housing, with heat dissipation fins mounted in the groove, thus increasing the area of ​​the heat dissipation fins, creating a more direct heat dissipation path for a heat-generating component, and thereby increasing the heat dissipation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To clarify the technical solutions of the application, the drawings required for the embodiments are briefly presented below. Obviously, the person skilled in the art can derive further drawings from these drawings without any inventive step. Fig. Figure 1 shows a cutaway side view of a photovoltaic inverter according to an embodiment of the application; Fig. Figure 2 shows a top view of an internal structure of a lower housing of the photovoltaic inverter according to an embodiment of the application; Fig. Figure 3 shows another cutaway side view of a photovoltaic inverter according to an embodiment of the application; Fig. Figure 4 shows a schematic structural view of a first printed circuit board of the photovoltaic inverter according to an embodiment of the application; Fig. Figure 5 shows a schematic structural view of a switch of the photovoltaic inverter according to an embodiment of the application; Fig. Figure 6 shows a schematic structural view of a PV terminal of the photovoltaic inverter according to an embodiment of the application; Fig. Figure 7 shows a schematic view of the mounting of the PV terminal of the photovoltaic inverter according to an embodiment of the application; and Fig. Figure 8 shows a schematic view of a rigid connecting element of the photovoltaic inverter according to an embodiment of the application. Reference symbol list:

[0017] 1 - Housing; 11 - Top cover; 12 - Bottom housing; 13 - Receiving chamber; 131 - First receiving chamber; 132 - Second receiving chamber; 14 - Protrusion; 141 - Thermally conductive contact section; 15 - Second connecting post; 16 - First connecting post; 2 - Printed circuit board assembly; 21 - First printed circuit board; 22 - Second printed circuit board; 221 - Recess; 222 - Capacitor; 223 - SMD resistor; 23 - Rigid connecting element; 231 - Nut; 3 - Switch; 31 - Switch body; 311 - Pin; 32 - Connecting rod; 33 - Rotary knob; 4 - PV terminal; 5 - Heat dissipation fin; 6 - Terminal connecting element; 7 - Foil terminal; 71 - Through hole. DETAILED EXECUTION FORMS

[0018] To facilitate a better understanding of the solutions presented in the present application for those skilled in the field, the embodiments of the present application are explained below in full and clearly with reference to the accompanying drawings. It is understood that the described embodiments represent only some of the embodiments, rather than all of them. All other embodiments that a person skilled in the art can obtain from the embodiments of the application without inventive steps are also to be included within the scope of protection of the application.

[0019] The description of the application makes it clear that the terms "first" and "second" are for descriptive purposes only, without indicating or suggesting the relative importance of the number of technical features involved.

[0020] In conventional photovoltaic inverter designs, the entire circuit board is typically mounted directly into the inverter housing from the front. A series of heat dissipation fins is attached beneath the housing to dissipate the heat generated during operation. The superimposition of the multiple layers—comprising the circuit board, the cooling fins, and the necessary protective casing—results in a comparatively large overall volume for the inverter. The photovoltaic inverter according to the present application employs a split circuit board design. By mounting a first and a second circuit board in opposite orientations, the components are positioned between the first and second circuit boards.This allows the intake chamber within the photovoltaic inverter to be fully utilized, thus reducing its thickness.

[0021] The photovoltaic inverter described in the present application will be discussed in more detail below with reference to the attached drawings.

[0022] See Fig. 1. Fig. Figure 1 shows a sectional side view of a photovoltaic inverter according to an embodiment of the application. The photovoltaic inverter according to the present application comprises a housing 1, which consists of a lower housing 12 and an upper cover 11. The housing 1 contains a receiving chamber 13, which is used for mounting and assembling the components of the photovoltaic inverter to form a protective structure. A printed circuit board assembly 2 is mounted in the receiving chamber 13, the printed circuit board assembly 2 comprising a first printed circuit board 21 and a second printed circuit board 22. The first printed circuit board 21 and the second printed circuit board 22 are arranged opposite each other in parallel. See Fig. 3. Fig. Figure 3 shows a further cutaway side view of a photovoltaic inverter according to an embodiment of the application. By way of example, the first printed circuit board 21 and the second printed circuit board 22 are arranged parallel to each other, with the components arranged on the opposite surfaces of the first printed circuit board 21 and / or the second printed circuit board 22. The surfaces of the first printed circuit board 21 and the second printed circuit board 22 are represented here. After assembly of the printed circuit board assembly 2, there is a distance L between the first printed circuit board 21 and the second printed circuit board 22, the distance L being greater than the height of the tall elements arranged on the first printed circuit board 21 and / or the second printed circuit board 22. For example, a switch 3 is mounted between the first printed circuit board 21 and the second printed circuit board 22, the distance L being greater than the height of the switch 3.

[0023] It should be noted that the term "and / or" here means that the distance L is greater than the height of the tall elements located on the first circuit board 21 and the second circuit board 22, where these elements can be mounted on either the first circuit board 21 or the second circuit board 22. Alternatively, the tall elements can also be mounted on both the first circuit board 21 and the second circuit board 22. "The tall elements" and "the short elements" are relative terms that refer to the geometric height of a component on the circuit board assembly 2. For example, the geometric height of switch 3 is greater than that of SMD resistor 223, so switch 3 can be considered a tall element, while SMD resistor 223 is considered a short element.On the first circuit board 21 or the second circuit board 22, other components, such as capacitors 222, etc., are also mounted. These components have a geometric height that is greater than that of the SMD resistor 223 but less than that of the switch 3. In this embodiment, such components are referred to as tall components. Alternatively, it can be assumed that all components whose geometric height exceeds that of the SMD resistor 223 are collectively referred to as tall components. In some other embodiments, it is provided, by way of example, that the components whose geometric height is greater than that of the inductive component are referred to as tall components.It follows that the terms “high element” and “low element” are relative terms that can be defined according to the specific requirements of the product application or on the basis of subjective judgment by those skilled in the art. Such definitions do not affect the implementation of the technical solutions proposed in the application, and this application does not restrict the dimensions of the high and low elements.

[0024] When the tall elements are arranged between the first circuit board 21 and the second circuit board 22, the distance L between the first circuit board 21 and the second circuit board 22 is greater than the geometric height of other short elements. In such a case, the short elements can also be mounted between the first and second circuit boards. Therefore, by arranging two circuit boards (namely the first circuit board 21 and the second circuit board 22), the installation space within the photovoltaic inverter housing can be fully utilized based on the different geometric heights of the tall and short elements. This allows for a hierarchical use of the vertical space, thereby reducing the thickness of the inverter housing and the volume of the photovoltaic inverter.

[0025] See more Fig. 3. The first printed circuit board 21 is mounted within the receiving chamber 13, with the first printed circuit board 21 lying parallel to the bottom surface of the lower housing 12. At this point, the first printed circuit board 21 is firmly connected to the bottom surface of the lower housing 12 via a first connecting post 16. The second printed circuit board 22 is arranged parallel to the first printed circuit board 21 and firmly connected to the bottom surface of the lower housing 12 via a second connecting post 15, the length of which is greater than that of the first connecting post 16. After completion of the assembly, the first printed circuit board 21 and the second printed circuit board 22 are arranged parallel to each other.All or some of the components that make up the photovoltaic inverter are mounted between the first circuit board 21 and the second circuit board 22, and these components include resistors, capacitors, switch assemblies, PV terminals and relays.

[0026] See also Fig. 8. Fig. Figure 8 shows a schematic view of a rigid connecting element of the photovoltaic inverter according to an embodiment of the application. A rigid connecting element 23 is provided between the first circuit board 21 and the second circuit board 22 to establish an electrical connection between the two. One end of the rigid connecting element 23 is provided with pins that are inserted into sockets of the conductive part of the first circuit board 21 and are soldered to them. The other end of the rigid connecting element 23 is bent, with a nut 231 provided on the underside of the bend. A through-hole is formed in the conductive part of the second circuit board 22.A bolt is passed through this through hole and engages in the nut 231 via a threaded connection, thereby firmly connecting the rigid connecting element 23 to the second circuit board 22 and establishing the electrical connection between them.

[0027] See more Fig. 3. A gap H exists between a surface of the second circuit board 22 facing away from the first circuit board 21 and an inner surface of the upper cover 11. This gap H provides a heat dissipation channel to improve heat dissipation within the inverter. It also allows the low-profile components to be mounted on a surface of the second circuit board 22 facing away from the first circuit board 21, further optimizing the circuit board arrangement.

[0028] In contrast to conventional photovoltaic inverters, the printed circuit board assembly 2 in the present application is divided into the first printed circuit board 21 and the second printed circuit board 22, with the two printed circuit boards arranged opposite each other. The taller elements are positioned between the first printed circuit board 21 and the second printed circuit board 22, thus maximizing the use of space in the receiving chamber through the height difference between the tall and shorter elements. This improves the hierarchical use of vertical space and therefore reduces the volume of the photovoltaic inverter.

[0029] As in Fig. 1 and Fig. As shown in Figure 3, in some embodiments, a portion of the bottom surface of the lower housing 12 projects into the receiving chamber 13, thereby forming a projection 14, which divides the receiving chamber 13 into at least two sub-receiving chambers. By way of example, in this embodiment, a groove with a cross-section approximately resembling a small door is formed on the outside of the lower housing 12 by the projection 14. Within the receiving chamber 13, this is divided into a first receiving chamber 131 and a second receiving chamber 132. The first receiving chamber 131 and the second receiving chamber 132 communicate with each other. The first circuit board 21 is arranged in the first receiving chamber 131. The second circuit board 22 covers an end of the first receiving chamber 131 and the second receiving chamber 132 located near the upper cover 11.At this point, a portion of the second circuit board 22 is positioned opposite the projection 14. In some embodiments, heat-generating components can be mounted in this area. Simultaneously, a thermally conductive contact section 141 is provided on the surface of the projection. By connecting the heat-generating components (such as MOS transistors or relays) to this thermally conductive contact section 141, the heat dissipation efficiency of the heat-generating components is improved, thereby ensuring stable operation of the device. The thermally conductive contact section 141 can comprise a viscous thermally conductive medium or a film-like product made of thermally conductive material, for example, thermal paste or a silicone thermal interface material.

[0030] The base surface of the lower housing 12 is provided with heat dissipation fins 5. These fins effectively dissipate heat from the interior of the housing 1 to the external environment, thus ensuring the stable and reliable operation of the photovoltaic inverter. Within the groove formed on the outside of the lower housing 12, the length of the heat dissipation fins 5 is greater than the depth of the groove. The heat dissipation fins 5 also form additional heat dissipation channels along the side walls of the groove. Simultaneously, the increased surface area of ​​the heat dissipation fins 5 within the groove improves the heat dissipation effect. By modifying the design and mounting position of the heat dissipation fins 5, their dimensions are reduced in a direction perpendicular to the base surface of the lower housing 12.This reduces the thickness of the inverter's housing, further compressing the volume of the photovoltaic inverter.

[0031] In other embodiments, the projection 14 can divide the receiving chamber 13 into several sub-receiving chambers, which are specifically designed according to the arrangement of the first circuit board 21 and / or the second circuit board 22. In other embodiments, the various sub-receiving chambers do not communicate with each other, with the first circuit board 21 and the second circuit board 22 each being mounted in separate sub-receiving chambers.

[0032] By having part of the base surface of the lower housing 12 project into the receiving chamber 13, thereby forming the projection 14 which divides the receiving chamber 13 into at least two sub-receiving chambers, the internal spatial arrangement is optimized and a more rational distribution of the printed circuit board assembly and other elements is enabled. At the same time, this facilitates flexible design according to the specific requirements for the arrangement of the printed circuit board assembly.

[0033] See Fig. 2. Fig. Figure 2 shows a top view of the internal structure of a lower housing of the photovoltaic inverter according to an embodiment of the application. A portion of the second circuit board 22 covering the first receiving chamber 131 is provided with a recess 221. The recess 221 allows the first circuit board 21 to be positioned opposite the upper cover 11. That is, when the upper cover 11 is open, the first circuit board 21 is directly visible and is not obscured by the second circuit board 22. During maintenance or replacement of the first circuit board 21, the second circuit board 22 does not interfere with the first circuit board 21, thus making maintenance more convenient and efficient.

[0034] See Fig. 4. Fig. Figure 4 shows a schematic structural view of a first printed circuit board of the photovoltaic inverter according to an embodiment of the application. The switch 3 and the terminal connection element 6 are mounted on the front of the first printed circuit board 21, with the switch 3 being provided with pins 311. The pins 311 are inserted into sockets on the conductive part of the first printed circuit board 21 and are firmly connected to the first printed circuit board 21 by soldering. The use of an integrated switch with rigid pin connections improves the stability and reliability of the electrical connection. At the same time, the elimination of cable connections optimizes the internal space and reduces the resistance and heat generation between the switch body and the first printed circuit board 21. This improves operational efficiency and simultaneously reduces the risk of contact failures, thereby increasing overall safety.

[0035] See Fig. 5. Fig. Figure 5 shows a schematic structural view of a switch of the photovoltaic inverter according to an embodiment of the application. In particular, the switch 3 comprises a switch body 31, a connecting rod 32, and a rotary knob 33, with the pins 311 arranged on the switch body 31. The switch body 31 is rigidly connected to the first circuit board 21 via the pins 311 and is mounted together with the first circuit board 21 in the housing 12. The connecting rod 32 extends through the side wall of the lower housing 12, with one end of the connecting rod 32 being connected to the switch body 31 and the other end of the connecting rod 32 being connected to the rotary knob 33. This arrangement allows the switch 3 to be controlled from outside the housing 1 and thus increases ease of use.

[0036] See Fig. 6 and Fig. 7. Fig. Figure 6 shows a schematic structural view of a PV terminal of the photovoltaic inverter according to an embodiment of the application. Fig. Figure 7 shows a schematic view of the assembly of the PV terminal of the photovoltaic inverter according to an embodiment of the application. The photovoltaic inverter according to the present application further comprises a PV terminal 4 and a foil clamp 7, wherein the first circuit board 21 is equipped with a terminal connection element 6, one end of the foil clamp 7 being connected to the PV terminal 4 and the other end of the foil clamp 7 being connected to the terminal connection element 6 by a locking mechanism. The terminal connection element 6 is a surface-mounted nut and / or a saddle clamp with a threaded connection hole. During assembly, one end of the PV terminal 4 is located on the outside of the lower housing 12 to establish a connection with the photovoltaic module. The other end of the PV terminal 4 is passed through the side of the lower housing 12 and connected to one end of the foil clamp 7.The other end of the foil clamp 7 has a through-hole 71. This through-hole 71 is aligned with the threaded connection hole of either a surface-mounted nut or a saddle clamp, after which both parts are firmly connected to each other with bolts. This process is simple and efficient. By providing the foil clamp 7, a rigid connection between the PV terminal 4 and the first printed circuit board 21 is enabled, thus eliminating cable connections. This optimizes the interior space and increases overall safety. The foil clamp 7 is a foil made of conductive metal (e.g., copper). The foil clamp 7 can have a plate-like structure or be curved to a certain degree, depending on the relative positions of the PV terminal 4 and the terminal connecting element 6. For example, the foil clamp 7, as shown in [Figure 1], has a [Figure 2] Fig. Figure 6 shows a “Z”-shaped structure.

[0037] In the photovoltaic inverter of the present application, the printed circuit board assembly 2 is divided into the first printed circuit board 21 and the second printed circuit board 22, which are arranged opposite each other. This improves the hierarchical use of space, reduces the volume of the photovoltaic inverter, and increases the overall space utilization. The provision of heat dissipation fins 5 on the bottom surface of the lower housing and the arrangement of the projection and the thermally conductive contact section 141 improve the heat dissipation efficiency of the heat-generating components, thereby ensuring stable operation of the device.By providing the recess 221 on the part of the second circuit board 22 covering the first receiving chamber 131, the first circuit board 21 is directly visible when the top cover is open. This facilitates maintenance and replacement of the first circuit board 21, making maintenance more convenient and efficient. The rigid connection between the switch 3 and the pins 311, and the locking connection of the foil terminal 7 and the PV terminal 4 to the terminal connecting element 6, improves the stability and reliability of the electrical connection. The elimination of cable connections optimizes the internal space allocation, reducing safety risks due to cable aging or faulty connections and thus increasing overall safety.By arranging the heat dissipation fins 5 within the groove formed on the outside of the lower housing 12 and forming heat dissipation channels with the side surfaces of the groove, the heat dissipation effect is simultaneously improved by the increased surface area of ​​the heat dissipation fins 5 within the groove. Furthermore, the stability of the entire structure is increased.

[0038] It is self-evident that, on the basis of the various embodiments described in the present application, those skilled in the art may combine, divide or reassemble the embodiments of the present application to derive other embodiments, all of which are within the scope of protection of the present application.

[0039] The specific embodiments mentioned above provide a further detailed explanation of the objectives, technical solutions, and advantageous effects of the embodiments of the present application. It is understood that the foregoing merely represents specific embodiments of the present application and does not serve to limit the scope of protection of the embodiments of the present application. All modifications, equivalent replacements, improvements, etc., made on the basis of the technical solutions of the embodiments of the present application fall within the scope of protection of the embodiments of the present application.

Claims

[1] Photovoltaic inverters, characterized by that it includes: a housing, wherein the housing is provided with a receiving chamber; and a printed circuit board assembly arranged in the receiving chamber, wherein the printed circuit board assembly comprises a first printed circuit board and a second printed circuit board arranged parallel to each other, and wherein high elements mounted on the first and second printed circuit boards are arranged on the opposite board surfaces of the first printed circuit board and / or the second printed circuit board. [2] Photovoltaic inverter according to claim 1, characterized by that the housing comprises a lower housing and an upper cover, wherein part of the bottom surface of the lower housing projects into the receiving chamber, thereby forming a projection that divides the receiving chamber into at least two sub-receiving chambers. [3] Photovoltaic inverter according to claim 2, characterized by, that the receiving chamber comprises a first receiving chamber and a second receiving chamber connected to each other, wherein the first printed circuit board is arranged in the first receiving chamber and the second printed circuit board covers an end of the first and second receiving chambers located near the top cover. [4] Photovoltaic inverter according to claim 3, characterized by , that a part of the second circuit board covering the first recording chamber is provided with a recess, so that the first circuit board lies opposite the upper cover. [5] Photovoltaic inverter according to claim 3, characterized by , that on the second circuit board a heat-generating component is mounted opposite the projection, wherein the surface of the projection is provided with a thermally conductive contact section via which the heat-generating component is connected to the projection. [6] Photovoltaic inverter according to claim 3, characterized by, that it further comprises a switch, the switch being provided with pins which are inserted into the sockets on the conductive part of the first circuit board and thus firmly connected. [7] Photovoltaic inverter according to claim 3, characterized by , that it further comprises a PV terminal and a foil terminal, wherein the first circuit board is equipped with a terminal connecting element, wherein one end of the foil terminal is connected to the PV terminal and the other end of the foil terminal is firmly connected to the terminal connecting element. [8] Photovoltaic inverter according to claim 7, characterized by that the clamping connecting element is a surface-mounted nut and / or a saddle clamp. [9] Photovoltaic inverter according to claim 2, characterized by, that heat dissipation ribs are mounted on the bottom surface of the lower housing, wherein a groove is formed on the outside of the bottom surface of the lower housing corresponding to the projection, and wherein the length of the heat dissipation ribs inside the groove exceeds the depth of the groove.

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