Photovoltaic inverter

Abstract

The invention discloses a photovoltaic inverter, the photovoltaic inverter comprises a power assembly, a heat radiator and a heat radiation fan, each current conversion pipe fitting of a second current conversion unit in the power assembly is sequentially arranged from the outer side of a circuit substrate to the inner side, and from the outer side to the inner side, the current conversion pipe fitting located at the position closer to the inner side is connected with the heat radiation fan. And compared with the other adjacent variable flow pipe fitting located closer to the outer side, the variable flow pipe fitting is far away from the first variable flow module, the arrangement direction of the variable flow pipe fittings enables the long edge of the internal wafer to form an included angle relative to the vertical direction, and the projection long edge of the internal wafer stretches across the at least two heat dissipation fins. The heat dissipation efficiency of the semiconductor device in the middle position in the power assembly of the photovoltaic inverter is better.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic inverters, and in particular to a photovoltaic inverter. Background Art

[0002] Photovoltaic inverters can convert direct current from photovoltaic modules into alternating current and transmit the alternating current to the grid or load. Photovoltaic modules include multiple photovoltaic strings, each of which includes multiple photovoltaic panels connected in series. Photovoltaic panels are used to convert light energy into electrical energy, and the electrical energy generated by each photovoltaic panel is direct current. In the power circuit board of the photovoltaic inverter, it generally includes a boost part and an inverter part. The boost part mostly uses a flying capacitor type BOOST boost circuit, which is connected to the external DC input and then boosted and output to the inverter part through the bus capacitor; the inverter part uses an NPC or ANPC three-level topology circuit, which converts the DC input into an AC output by opening and closing the switch tube.

[0003] Due to the large number of semiconductor devices on the power circuit board, the power circuit board generates a huge amount of heat, and active heat dissipation needs to be performed through an external heat sink. The heat-conducting surface on one side of the heat sink will be attached to the heat dissipation surface of the semiconductor device on the circuit board, and then the fan will be used to drive the air flow at the position of the heat sink fins to take away the heat from the heat sink. However, there is a problem of uneven heat dissipation of the semiconductor devices on the circuit board. Specifically, the upper side of the power circuit board is generally set as the inverter part, including multiple groups of inverter units arranged in the left-right direction, and the lower side of the power circuit board is the boost part, including multiple groups of boost units arranged in the left-right direction and the up-down direction, and the heat sink is usually shared by the boost part and the inverter part, that is, the wind flow direction defined by the same heat sink fin usually flows in the up-down direction of the board body, and the inverter part located above and the boost part located below will share the same air duct defined by the heat sink fin. In the inverter part, the semiconductor device located in the middle position in the left-right direction will be affected by the heat generated by other semiconductor devices on its left and right sides, as well as the heat generated by the semiconductor devices in the boost part below it. At the same time, the airflow direction of the radiator is from the boost part to the inverter part. The heat flow driven by the airflow will cause heat accumulation at the inverter part. Due to the influence of multiple factors, the heat dissipation efficiency of the semiconductor device located in the middle position of the inverter part is poor. Summary of the invention

[0004] The object of the present invention is to overcome the above-mentioned defects or problems existing in the background technology and to provide a photovoltaic inverter, in which the semiconductor device located in the middle of the power component has better heat dissipation efficiency.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] Technical solution 1: A photovoltaic inverter, comprising: a power component, comprising a circuit substrate, a first inverter module and a second inverter module arranged on the circuit substrate, which are used to realize the inversion and boost functions through the first inverter module and the second inverter module; a heat sink, whose heat dissipation surface is close to the first inverter module and the second inverter module on the power component, and the heat dissipation fins of the heat sink extend in the up-down direction and are arranged side by side in the left-right direction; and a cooling fan, which is located at the lower side of the heat sink and is suitable for supplying air toward the heat sink in the up-down direction; in the power component, the first inverter module and the second inverter module are formed by a plurality of semiconductor switching devices arranged on the first surface of the circuit substrate to form a corresponding plurality of first inverter units and second inverter units, wherein the first inverter module is located at the upper side of the second inverter module, and the first inverter units in the first inverter module are arranged in sequence in the left-right direction; the middle position of the circuit substrate in the left-right direction is defined as the inner side, and the positions on both sides are defined as the outer side; the second inverter unit includes A plurality of current converter components formed by semiconductor switching devices, each current converter component of each second current converter unit is arranged in sequence from the outside to the inside of the circuit substrate, and from the outside to the inside, the current converter component located closer to the inside is farther away from the first current converter module than another adjacent current converter component located closer to the outside; each second current converter unit belonging to the same outside position is arranged in sequence along the up-down direction in a manner that the respective current converter components correspond to each other, and at least one group of current converter components located on the inside and belonging to different second current converter units are arranged in a direction inclined from top to bottom and from outside to inside; the current converter components used in the second current converter unit all include at least one wafer component for switching the circuit on and off, the wafer component is in the shape of a rectangle, and the arrangement direction of the current converter components is configured to be suitable for the long side of the wafer component inside to have an angle relative to the up-down direction; the spacing of the heat sink fins on the heat sink is configured to be suitable for the long side of the projection of each wafer component on the plane of the circuit substrate to span at least two of the heat sink fins.

[0007] Technical solution 2 based on technical solution 1: the arrangement direction of at least part of the current conversion tubes used in the second current conversion unit is configured to be suitable for making the long side of the wafer component inside it perpendicular to the up-down direction.

[0008] Technical solution three based on technical solution one or two: the shape of the converter tube used in the second converter unit is rectangular, and the converter tube whose arrangement direction is such that the width direction is perpendicular to the left and right direction of the circuit substrate is defined as a type of tube, and the long side of the wafer component in the type of tube is perpendicular to the width direction of the converter tube to which it belongs.

[0009] Technical solution four based on technical solution three: define the converter tube whose arrangement direction is such that the length direction is perpendicular to the left-right direction of the circuit substrate as a second-class tube, and the long side of the wafer component in the second-class tube is perpendicular to the length direction of the converter tube to which it belongs.

[0010] Technical Solution 5 based on Technical Solution 4: Define the three types of current transformers whose arrangement direction is such that the length direction obliquely intersects with the left and right directions of the circuit substrate, and the long sides of the wafer components in the three types of tubes are perpendicular to the width direction of the current transformers to which they belong.

[0011] Technical solution six based on technical solution five: For multiple second current conversion units belonging to the same outer position, except for the outermost current conversion tube, the arrangement directions of other current conversion tubes are inclined from top to bottom and from outside to inside.

[0012] Technical Solution 7 based on Technical Solution 5: For multiple second current conversion units belonging to the same outer position, the arrangement directions of the corresponding current conversion tubes at the upper and lower positions are all inclined from top to bottom and from outside to inside.

[0013] Technical solution eight based on technical solution six or seven: the types of the current converter components include high-loss components and low-loss components. In the same second current converter unit, the high-loss components are located outside the circuit substrate relative to the low-loss components.

[0014] Technical solution nine based on technical solution six or seven: the first conversion module includes three first conversion units arranged in sequence along the left and right directions at a preset distance, and the boundary between the high-loss pipe and the low-loss pipe in each second conversion unit corresponds to the boundary between the first conversion unit located in the middle position and the two second conversion units located on both sides.

[0015] Technical solution ten based on technical solution eight: the high-loss tube component is a switch tube component with controlled opening and closing, and the low-loss tube component is a diode component used to control the direction of current. Each second current conversion unit includes two groups of switch tube components and two groups of diode components. Each group or every two groups of switch tube components and diode components are suitable for being arranged on the circuit substrate as the current conversion tube component.

[0016] It can be seen from the above description of the present invention that, compared with the prior art, the present invention has the following beneficial effects:

[0017] Technical solution 1 provides a photovoltaic inverter, the power component of which is used to realize the inversion and boost functions. When the power component is working, the semiconductor switching devices in the power converter will generate a lot of heat, which can be dissipated by the heat sink and the cooling fan. The power component includes a circuit board and two converter modules, wherein the first converter units in the first converter module are arranged on the circuit board in sequence along the left and right directions, and the second converter module is located below the first converter module; in the conventional circuit device layout, due to the arrangement of the first converter units in the first converter module, the first converter unit located in the middle position will be affected by the other first converter units on its left and right sides, as well as the second converter unit located below it. At the same time, because the wind flow direction of the radiator is from the second converter module to the first converter module, heat will accumulate, so the first converter unit at this position will have the problem of poor heat dissipation efficiency;

[0018] In the present technical solution, the layout of the second converter module is improved, and the converter tubes of each second converter unit in the second converter module are arranged in a stepped manner from the outside to the inside, so that each converter tube is gradually away from the first converter module, thereby making the converter tubes of the second converter unit near the middle position farther away from the first converter module, so that the heat generated by the converter tubes of the second converter unit can have a sufficient distance on the corresponding heat dissipation fins to be conducted to other areas where semiconductor devices are not arranged, instead of only being able to be conducted to the first converter unit located at the end of the wind flow, thereby reducing the influence of the heat generation of this part of the converter tubes on the heat dissipation of the first converter unit; however, simply moving this part of the converter tubes to a position farther away from the first converter module either requires increasing the size of the circuit substrate in the up-down direction, or reducing the size of the converter tubes corresponding to the positions in the second converter units adjacent in the up-down direction. spacing; when the size of the circuit substrate is limited, the technical solution creatively tilts the arrangement direction of the multiple converter tubes belonging to different second converter units located on the inner side from top to bottom and from outside to inside, so that the converter tubes that are moved downward are displaced toward the left or right in the vertical direction. This displaced layout can ensure that there is a sufficient safety distance between adjacent converter tubes, and at the same time can reduce the spacing of this part of the converter tubes in the vertical direction, so that the converter tubes can be arranged in a stepped distribution without changing the size of the circuit substrate; and, since this part of the converter tubes are arranged in an inclined direction, the airflow of the radiator passes through fewer converter tubes per unit area in the process of flowing from the position of the second converter module to the position of the first converter module, so the heat accumulated at the position of the first converter module is less, which is more conducive to the heat dissipation of the first converter unit at the middle position.

[0019] In addition, usually, there is also a wafer device inside the semiconductor switch device, which is a key component that controls the on and off of the circuit inside the semiconductor switch device and is also the main heat source of the semiconductor switch device; generally speaking, the wafer component is usually composed of a relatively large wafer or a combination of multiple relatively small wafers. In practical applications, due to the small physical size of the wafer component, when multiple semiconductor devices form a certain layout, it is difficult to make the wafer components in each semiconductor device form a good thermal conductivity relationship with the heat sink fins, resulting in a higher operating temperature of some semiconductor devices.

[0020] Therefore, in order to further improve the overall heat dissipation efficiency and avoid heat accumulation on the power component, the arrangement direction of the converter tube is also limited. According to the position of the wafer component inside the converter tube, the arrangement direction of the converter tube is configured to be suitable for the long side of the wafer component inside to have an angle relative to the up-down direction, and at least two heat sink fins can correspond to one wafer component; because the converter tube is a semiconductor switching device, the main heat generating part is the wafer component inside it, when multiple heat sink fins are corresponding to one wafer component, the wafer component can take away heat through more heat sink fins, compared with the conventional situation of making the long side direction of the wafer component parallel to the up-down direction, it can better improve the overall heat dissipation efficiency of the power component.

[0021] In the second technical solution, at least part of the current converter components are arranged in a direction such that the long side of the wafer component inside is perpendicular to the up-down direction. With this arrangement, the long side of the wafer component can span more cooling fins, resulting in higher cooling efficiency.

[0022] In technical solution three, the shape of the converter tube is also rectangular, and a class of tubes is defined, the width direction of these class of tubes is perpendicular to the left and right direction of the circuit substrate. At this time, the long sides of the wafer components in these class of tubes are perpendicular to the width direction of the converter tube, thereby ensuring that the long sides of these wafer components are perpendicular to the up and down directions, and can correspond to more heat dissipation fins, thereby improving the heat dissipation efficiency.

[0023] In technical solution four, two types of pipe fittings are defined, and the length directions of these two types of pipe fittings are perpendicular to the left-right direction of the circuit substrate. At this time, the long sides of the wafer components in these two types of pipe fittings are perpendicular to the length directions of the variable current pipe fittings, thereby ensuring that the long sides of these wafer components are perpendicular to the up-down direction, and can correspond to more heat dissipation fins, thereby improving the heat dissipation efficiency.

[0024] In technical solution five, three types of pipe fittings are defined, and the length directions of these three types of pipe fittings are obliquely intersected with the left and right directions of the circuit substrate. At this time, the long sides of the wafer components in these type two pipe fittings are perpendicular to the width directions of the converter pipe fittings, so that the long sides of these wafer components can also be obliquely intersected with the up and down directions, thereby improving the heat dissipation efficiency of the obliquely arranged converter pipe fittings.

[0025] In technical solutions six and seven, part or all of the current converter components can be arranged along an inclined direction. Based on the same natural principle, less heat will be accumulated in the first current converter module, which is beneficial to the heat dissipation of the entire first current converter module. At the same time, the distance between the current converter components in the same second current converter unit can be shortened, and the length of the electrical connection line in the circuit substrate can be shortened, thereby reducing the complexity of the layout of the electrical connection line of the circuit substrate.

[0026] In Technical Solution 8, the converter components in the second converter unit are divided into high-loss components and low-loss components according to their losses. In a switching cycle, the high-loss components generate more heat than the low-loss components. The low-loss components with lower heat generation are arranged on the inner side of the circuit substrate, and the high-loss components with higher heat generation are arranged on the outer side of the circuit substrate, so as to further reduce the influence of the heat generation of the converter components on the heat dissipation of the first converter unit located in the middle position.

[0027] In technical solution nine, three first current conversion units are provided, and the first current conversion unit at the middle position is spaced apart from the first current conversion units at the two side positions by a preset distance to form a separated gap. The portion of the first current conversion unit at the middle position adjacent to the gap is the portion with the worst heat dissipation performance of the first current conversion unit, so that the boundary between the high-loss pipe and the low-loss pipe corresponds to this gap, thereby reducing the influence of the high-loss pipe on the heat dissipation of the first current conversion unit at the middle position.

[0028] In technical solution ten, the high-loss tube components are switch tube components with controlled opening and closing, and the low-loss tube components are diode components for controlling the direction of current. Each group or every two groups of switch tube components and diode components can be arranged as current converter components on the circuit substrate. That is to say, two groups of switch tube components can be used as a current converter component, and two groups of diode components can be arranged as a combination of two current converter components. This preferred arrangement scheme can ensure that the current converter components located on the outside have an appropriate distance from the first current converter module when the size of the circuit substrate is limited, while the distance between the multiple current converter components located on the inside and the first current converter module is maximized. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 A schematic diagram of the layout of the first surface of the circuit substrate of the power component provided in Embodiment 1 of the present invention;

[0031] Figure 2 A schematic diagram of the layout of the second surface of the circuit substrate of the power component provided in Embodiment 1 of the present invention;

[0032] Figure 3 A schematic diagram of the types of current converters and the positions of wafer components therein in Example 1 of the present invention;

[0033] Figure 4 A schematic diagram of the layout of a flying circuit board of a power component provided in Embodiment 1 of the present invention;

[0034] Figure 5 A schematic diagram of the layout of the first surface of the circuit substrate of the power component provided in Embodiment 2 of the present invention;

[0035] Figure 6 A circuit diagram of the second converter module in the power assembly provided in Embodiment 1 or 2 of the present invention.

[0036] Description of main reference numerals:

[0037] Circuit substrate 1; first current conversion module 2; second current conversion module 3; first current conversion unit 4; second current conversion unit 5; first switch tube 6; second switch tube 7; first diode 8; second diode 9; flying capacitor 10; flying unit 11; capacitor module 12; first capacitor unit 13; second capacitor unit 14; flying circuit board 15; through hole 16; flying diode 17; wafer component 18; first pipe fitting 19; second pipe fitting 20; third pipe fitting 21; heat sink fin 22. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are preferred embodiments of the present invention and should not be regarded as excluding other embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In the claims, description and the above-mentioned drawings of the present invention, unless otherwise clearly defined, the use of terms such as "first", "second" or "third" etc. are for distinguishing different objects rather than for describing a specific order.

[0040] In the claims, specification and the above-mentioned drawings of the present invention, unless otherwise explicitly defined, directional words, such as the terms "center", "lateral", "longitudinal", "horizontal", "vertical", "top", "bottom", "inside", "outside", "up", "down", "front", "back", "left", "right", "clockwise", "counterclockwise", etc., indicating directions or positional relationships are based on the directions and positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the specific protection scope of the present invention.

[0041] In the claims, specification and the above drawings of the present invention, unless otherwise clearly defined, if the term "fixed connection" or "fixed connection" is used, it should be understood in a broad sense, that is, any connection method without a displacement relationship and relative rotation relationship between the two, that is to say, including non-detachable fixed connection, detachable fixed connection, integrated connection and fixed connection through other devices or elements.

[0042] In the claims, description and drawings of the present invention, if the terms "include", "have" and their variations are used, they are intended to mean "including but not limited to".

[0043] Example 1

[0044] Embodiment 1 of the present invention provides a photovoltaic inverter, which includes a power component, a heat sink, a cooling fan and other conventional devices, wherein the power component is connected to a PV connecting board in the photovoltaic inverter, receives a DC input from the PV connecting board, and converts the DC input into an AC output after boosting and inverting.

[0045] Among them, the power component includes a circuit substrate 1, a first inverter module 2 and a second inverter module 3 arranged on the circuit substrate 1, which are used to realize the inversion and boosting functions through the first inverter module 2 and the second inverter module 3; the heat dissipation surface of the radiator is attached to the first inverter module 2 and the second inverter module 3 on the power component, and the heat dissipation fins 22 of the radiator extend in the up and down directions and are arranged side by side in the left and right directions; the cooling fan is located at the lower side of the radiator and is suitable for supplying air toward the radiator in the up and down directions.

[0046] For detailed instructions on up, down, left, and right directions, please refer to Figure 1 , Figure 1The arrow located at the lower side of the circuit substrate 1 in the figure indicates the air supply direction of the cooling fan. It is easy to understand that although the heat sink is not shown, the heat sink fins 22 on the heat sink are vertically arranged in a sheet shape, and a plurality of heat sink fins 22 are provided on the heat sink. The heat sink fins 22 are arranged at a fixed distance in the left-right direction, and the heat sink fins 22 extend in the up-down direction. Thus, air supply channels are formed in the gaps between the heat sink fins 22, and the airflow of the cooling fan can supply air through the air supply channels and take away the heat on the heat sink fins 22, so that the heat sink fins 22 are cooled, thereby cooling the semiconductor switch devices on the power components.

[0047] The specific structures of the radiator and the cooling fan are not described in detail here, and those skilled in the art can select appropriate radiator and cooling fan according to actual needs.

[0048] The power component includes a circuit substrate 1 and a first inverter module 2 and a second inverter module 3 arranged on the circuit substrate 1. The first inverter module 2 and the second inverter module 3 are formed with a plurality of semiconductor switching devices arranged on the first surface of the circuit substrate 1 to form a corresponding plurality of first inverter units 4 and second inverter units 5, wherein the first inverter module 2 is located above the second inverter module 3, and the first inverter units 4 in the first inverter module 2 are arranged sequentially along the left-right direction.

[0049] In this embodiment, the first converter module 2 is an inverter module, which is used to realize the inverter function of converting DC input into AC output; the second converter module 3 is a boost module, which is used to convert the connected low-voltage DC power into high-voltage DC power and transmit it to the inverter module. The inverter module adopts a conventional ANPC or NPC type three-level topology circuit, and realizes the inverter function through the controlled opening and closing of the power tubes therein, such as IGBT modules, MOSFET modules, etc. The boost module adopts Figure 6 The details of the boost circuit and the boost module shown will be described below. In addition to the above-mentioned IGBT module and MOSFET module, the semiconductor switch device may also include conventional diodes, triodes, etc., which are not limited here.

[0050] Reference Figure 1In this embodiment, the first current conversion module 2 includes three first current conversion units 4, which correspond to the three-phase output of the alternating current, and each has a complete set of ANPC or NPC type three-level topology circuits; the three first current conversion units 4 are arranged in sequence along the left and right directions, and can be regarded as a first current conversion unit 4 arranged at each of the three positions on the left, middle, and right, and there is a preset distance between the three first current conversion units 4, forming a gap between adjacent first current conversion units 4, and this gap can spatially separate the three-phase first current conversion units 4 to avoid mutual influence of the three-phase AC output. When the power component is working, the three first current conversion units 4 will generate a large amount of heat, and the first current conversion unit 4 located in the middle position will be affected by the heat of the two first current conversion units 4 on the left and right sides, resulting in a decrease in the heat dissipation efficiency of the first current conversion unit 4 located in the middle position. At the same time, the second inverter module 3 is arranged below the first inverter module 2, and the cooling fins 22 of the radiator extend in the up and down directions, and the wind flows from bottom to top. The heat of the second inverter module 3 will affect the first inverter module 2 located above it along the wind flow. If the layout of the first inverter module 2 is not improved, it is obvious that the heat dissipation efficiency of the first inverter unit 4 located in the middle position of the first inverter module 2 will be greatly reduced.

[0051] To this end, the middle position of the circuit substrate 1 in the left-right direction is defined as the inner side, and the positions on both sides are defined as the outer side; the second current conversion unit 5 includes a plurality of current conversion tubes formed by semiconductor switching devices, and the current conversion tubes of each second current conversion unit 5 are arranged in sequence from the outer side to the inner side of the circuit substrate 1, and from the outer side to the inner side, the current conversion tube located closer to the inner side is farther away from the first current conversion module 2 than another adjacent current conversion tube located closer to the outer side; the second current conversion units 5 belonging to the same outer side position are arranged in sequence along the up-down direction in a manner that their respective current conversion tubes correspond to each other, and there is at least one group of current conversion tubes located on the inner side and belonging to different second current conversion units 5, the arrangement direction of which is inclined from top to bottom and from outside to inside.

[0052] Furthermore, the converter tubes used in the second converter unit 5 all include at least one wafer component 18 for switching the circuit on and off, the wafer component 18 is rectangular in shape, and the arrangement direction of the converter tubes is configured to be suitable for the long sides of the wafer components 18 inside to have an angle relative to the up-down direction. At the same time, the spacing of the heat dissipation fins 22 on the heat sink is configured to be suitable for the projection of each wafer component 18 on the plane of the circuit substrate 1 to span across at least two heat dissipation fins 22.

[0053] Among them, the wafer component 18 is composed of two or more smaller wafers. The wafer is the basis for the manufacture of semiconductor switching devices. When manufacturing semiconductor switching devices, firstly, ion implantation or diffusion technology is used to introduce impurity atoms in a specific area of ​​single crystal silicon to change the conductivity type of the area, and then an insulating layer or a metal connection layer is formed on the surface of the wafer. After that, multiple wafers are combined to form the wafer component 18, and then the wafer component 18 is packaged to obtain the final semiconductor switching device. In addition to the packaging shell of the semiconductor switching device, the key component inside it that plays a role in controlling the on and off of the circuit is the wafer 18, and the main heat source of the semiconductor switching device is also the wafer 18. In the converter tube used in this embodiment, the wafer 18 inside it is rectangular.

[0054] In addition, the arrangement direction of the above-mentioned current converter is configured to be suitable for making the long side of the wafer 18 inside it have an angle relative to the up and down direction, which means that the arrangement direction of the current converter is set based on the long side direction of the wafer 18 inside the current converter, so that the long side direction of the wafer 18 has a certain inclination angle with the up and down direction, and this inclination angle can be an acute angle, and the arrangement direction of at least part of the current converter is configured to be suitable for making the long side of the wafer 18 inside it perpendicular to the up and down direction.

[0055] Reference Figure 1 The above-mentioned expressions of inside and outside are actually relative. The circuit substrate 1 is divided into a left part and a right part with the midline position in the left and right directions as the boundary. In the left part or the right part, when the position of one component relative to another component is closer to the left or right edge of the circuit substrate 1, it can be said that the component is arranged at the outer position relative to the other component. Obviously, for the left part of the circuit substrate 1, multiple groups of second inverter units 5 can be arranged, and for the right part of the circuit substrate 1, multiple groups of second inverter units 5 can also be arranged. The number of second inverter units 5 in the left part and the right part can be the same or different, but in order to balance the arrangement of the second inverter module 3 on the circuit substrate 1, it is preferred that the layout method in which the number of second inverter units 5 in the left part and the right part is the same.

[0056] Reference Figure 6 , which shows the circuit topology of a second current conversion unit 5. As a BOOST boost circuit, the types of current conversion tubes in the second current conversion unit 5 include switch tubes with controlled opening and closing and diodes for controlling the current direction. At the same time, each second current conversion unit 5 includes two groups of switch tubes and two groups of diodes. The two groups of switch tubes correspond to Figure 6 The two diodes Q1 and Q2 in the circuit correspond to Figure 6D1 and D2 in the circuit. According to the heat loss of the semiconductor switching device in a switching cycle, the types of converter tubes are divided into high-loss tubes and low-loss tubes. High-loss tubes have higher heating efficiency than low-loss tubes. For a converter tube, the semiconductor switching devices it includes may be as follows: the first type includes a group of switch tubes; the second type includes a group of diode devices; the third type includes two groups of switch tubes; the fourth type includes two groups of diode devices. Obviously, since a second converter unit 5 only includes two groups of switch tubes and two groups of diode devices, the first and third types are mutually exclusive, and the second and fourth types are also mutually exclusive.

[0057] Reference Figure 1 In this embodiment, a second current conversion unit 5 includes three current conversion tubes, one of which includes two groups of switch tubes, and the other two current conversion tubes each include a group of diodes. The three current conversion tubes are arranged in sequence from the outside to the inside of the circuit substrate 1. Figure 1 Taking the second current conversion unit 5 with a label as an example, the second current conversion unit 5 is located on the left side of the circuit substrate 1, and the three current conversion tubes are arranged in sequence from the left side to the right side. The leftmost current conversion tube is at the highest position, and the positions of the two current conversion tubes on the right are moved down in sequence, so that from the outside to the inside, the current conversion tube closer to the inside is farther away from the first current conversion module 2 than another adjacent current conversion tube closer to the outside, that is, the current conversion tubes are distributed in a stepped manner that gradually moves downward from the outside to the inside. At the same time, the converter tube that is closer to the inner position is closer to the middle position of the circuit substrate 1, which corresponds to the position of the first converter unit 4 located in the middle position in the upper first converter module 2. However, the converter tube that is closer to the middle position is actually farther away from the first converter module 2 in the up and down directions than the converter tube on the outer side, so that the heat generated by the converter tube of the second converter unit 5 can have a sufficient distance on the corresponding heat sink fins 22 to be conducted to other areas where semiconductor devices are not installed, rather than only being conducted to the first converter unit 4 located at the end of the wind flow, thereby reducing the influence of the heat generated by this part of the converter tube on the heat dissipation of the first converter unit 4.

[0058] However, simply moving this part of the current-converting tubes to a position farther away from the first current-converting module 2 requires either increasing the size of the circuit substrate 1 in the vertical direction, or reducing the vertical spacing of the corresponding current-converting tubes in the second current-converting units 5 adjacent to each other in the vertical direction. When the size of the circuit substrate 1 is limited, this embodiment tilts the arrangement direction of the multiple current-converting tubes located on the inner side and belonging to different second current-converting units 5 from top to bottom and from outside to inside, so that the part of the current-converting tubes that are moved downward are misaligned toward the left or right in the vertical direction. Specifically, referring to Figure 1In this embodiment, the left part includes three second current conversion units 5, and the three second current conversion units 5 are arranged in sequence along the up-down direction, and the corresponding current conversion tubes in the three second current conversion units 5 at the up-down position are arranged obliquely from top to bottom and from outside to inside. The current conversion tubes corresponding at the up-down position referred to here mean that when the three second current conversion units 5 have three current conversion tubes arranged in sequence along the left-right direction, the leftmost current conversion tubes correspond in position in the up-down direction, the middle current conversion tubes correspond in position in the up-down direction, and the rightmost current conversion tubes correspond in position in the up-down direction. Therefore, the three leftmost current conversion tubes are arranged obliquely relative to the up-down direction along the preset oblique direction, the three middle current conversion tubes are arranged obliquely relative to the up-down direction along the same oblique direction, and the three rightmost current conversion tubes are also arranged obliquely relative to the up-down direction along the same oblique direction. Among them, in a second current conversion unit 5, the current conversion tubes located at the outermost side include two groups of switch tubes, and each of the two groups of switch tubes includes two switch tubes, which are Figure 1 The first switch tube 6 and the second switch tube 7 are arranged in the left-right direction, and the two groups of switch tubes are arranged in the up-down direction; the current converter located in the middle position includes a group of diodes, and the group of diodes includes two diodes, which are Figure 1 The first diode 8 in the figure is arranged in the same direction as the tilt direction of the converter tube; the converter tube located on the right side includes a group of diodes, which includes two diodes. Figure 1 The second diode 9 in the circuit board 5 is arranged in the left-right direction. The above arrangement not only allows the three current conversion tubes in a second current conversion unit 5 to be distributed in a stepped manner, but also allows the multiple current conversion tubes at the inner position to be arranged in an inclined manner in a preset direction in the up-down direction, and this inclined arrangement does not require increasing the size of the circuit substrate 1 in the left-right direction and the up-down direction. This staggered layout can ensure that there is a sufficient safety distance between adjacent current conversion tubes, and at the same time can reduce the spacing of this part of the current conversion tubes in the up-down direction, so that the current conversion tubes can be set to be distributed in a stepped manner without changing the size of the circuit substrate 1. In addition, since this part of the current conversion tubes is arranged in an inclined direction, the airflow of the radiator passes through fewer current conversion tubes per unit area in the process of flowing from the position of the second current conversion module 3 to the position of the first current conversion module 2, so the heat accumulated at the position of the first current conversion module 2 is less, which is more conducive to the heat dissipation of the first current conversion unit 4 in the middle position.

[0059] Reference Figure 1As can be seen from the above description, in the same second converter unit 5, the switch tube, which is a high-loss tube, is located outside the circuit substrate 1 relative to the diode, which is a low-loss tube. In this way, the high-loss tube with a higher heat generation is arranged outside the circuit substrate 1, further reducing the effect of the heat generated by the converter tube on the heat dissipation of the first converter unit 4 located in the middle.

[0060] Reference Figure 1 , the boundary between the high-loss pipe and the low-loss pipe in each second current conversion unit 5 corresponds to the boundary between the first current conversion unit 4 located in the middle and the two second current conversion units 5 located on both sides. As described above, a spacing space is formed between the first current conversion unit 4 in the middle and the first current conversion units 4 on both sides, and this spacing space is the boundary between the first current conversion unit 4 and the first current conversion units 4 on both sides; similarly, in each second current conversion unit 5, there is also a boundary between the high-loss pipe and the low-loss pipe, and this boundary extends in an inclined shape in the same direction as the inclination of the current conversion pipe, and is located between the leftmost current conversion pipe and the middle current conversion pipe, which can also be regarded as a spacing space with a certain width. The two boundaries referred to here correspond to each other, and refer to the boundaries between the inclined current conversion pipes, which can be translated upward to have an interlaced position with the connection between the first current conversion units 4 extending in the up and down directions. Through such a layout arrangement, high-loss pipes with higher heat generation can be excluded from the range of the first converter unit 4 located in the middle position, thereby reducing the influence of the high-loss pipes on the heat dissipation efficiency of the first converter unit 4.

[0061] At the same time, refer to Figure 3 , the shape of the current transformer used is also rectangular, and according to the arrangement position of the wafer 18 inside the current transformer and the arrangement mode of the current transformer, each current transformer in the second current transformer module 3 is divided into a first type of transformer 19, a second type of transformer 20 and a third type of transformer 21. Specifically, the current transformer whose arrangement direction is defined as a width direction perpendicular to the left-right direction of the circuit substrate 1 is defined as a first type of transformer 19, and the long side of the wafer 18 in the first type of transformer 19 is perpendicular to the width direction of the current transformer to which it belongs; the current transformer whose arrangement direction is defined as a length direction perpendicular to the left-right direction of the circuit substrate 1 is defined as a second type of transformer 20, and the long side of the wafer 18 in the second type of transformer 20 is perpendicular to the length direction of the current transformer to which it belongs; the current transformer whose arrangement direction is defined as a length direction obliquely intersecting with the left-right direction of the circuit substrate 1 is defined as a third type of transformer 21, and the long side of the wafer 18 in the third type of transformer 21 is perpendicular to the width direction of the current transformer to which it belongs.

[0062] Specifically, Figure 1Take the second converter unit 5 as an example, the two first switch tubes 6 and the two second switch tubes 7 are all type I tubes 19, and the long sides of these switch tubes are perpendicular to the up-down direction; the two first diodes 8 are type III tubes 21, and the long sides of these switch tubes are inclined to the up-down direction; the two second diodes 9 are type II tubes 20, and the long sides of these switch tubes are perpendicular to the left-right direction. However, in other second converter units 5, the type of converter tube is not absolutely related to the configuration of its switch tube. For example, in Figure 1 In a second current conversion unit 5 below the marked second current conversion unit 5 , two second diodes 9 belong to a type of pipe 19 .

[0063] Reference Figure 3 , Figure 3 The positions of the wafers 18 inside the three types of tubes 21 and their positional relationship with the heat dissipation fins 22 of the heat sink are shown. Figure 3 The dotted box in the figure represents the heat sink fins 22 at the corresponding positions. It can be seen that by setting the spacing of the heat sink fins 22 and adjusting the position of the variable current tube, each wafer 18 at least spans two heat sink fins 22 in its length direction, thereby improving the heat dissipation capacity of the heat sink fins 22 to the wafer 18.

[0064] Generally speaking, usually, semiconductor switching devices also have wafer devices inside, which are key components that control the on and off of the circuit inside the semiconductor switching device, and are also the main source of heat for the semiconductor switching device; generally speaking, the wafer component is usually composed of a relatively large wafer or a combination of multiple relatively small wafers. In practical applications, due to the small physical size of the wafer component, when multiple semiconductor devices form a certain layout, it is difficult for the wafer components in each semiconductor device to form a good thermal conductivity relationship with the radiator fins, resulting in a higher operating temperature for some semiconductor devices. Therefore, in order to further improve the overall heat dissipation efficiency and avoid heat accumulation in the power components, the layout direction of the converter tube is also limited. Among them, according to the position of the wafer component inside the converter tube, the arrangement direction of the converter tube is configured to be suitable for making the long side of the wafer component inside it have an angle with respect to the up and down direction, and at the same time, at least two heat sink fins can correspond to one wafer component; because the converter tube is a semiconductor switching device, the main heat generating part of the converter tube is the wafer component inside it. After multiple heat sink fins are made to correspond to one wafer component, the wafer component can take away heat through more heat sink fins. Compared with the conventional situation where the long side direction of the wafer component is parallel to the up and down direction, the overall heat dissipation efficiency of the power component can be better improved.

[0065] Reference Figure 2Each of the second current conversion units 5 further includes a flying capacitor 10, which is disposed on the second surface of the circuit substrate 1 and is electrically connected to the corresponding current conversion tube; in each of the second current conversion units 5 belonging to the same outer position, each flying capacitor 10 is correspondingly arranged from top to bottom and from outside to inside to form two flying units 11 arranged in the left-right direction; the position of the flying unit 11 corresponds to the boundary between the high-loss tube and the low-loss tube in each of the second current conversion units 5 belonging to the same outer position. Specifically, the flying capacitor 10 is Figure 6 C1 in the circuit, one end of the flying capacitor 10 in each second current conversion unit 5 is connected to the cathode of the diode D1, and the other end is connected to the midpoint of the two switch tubes Q1 and Q2, which can balance the voltage and store energy. Figure 2 In the figure, the flying capacitors 10 of the three second current conversion units 5 on the left are combined to form a flying unit 11, and the flying capacitors 10 of the three second current conversion units 5 on the right are also combined to form a flying unit 11. Since the two ends of the flying capacitor 10 are connected to the switch tube and the diode, the three groups of flying capacitors 10 in each flying unit 11 are also arranged along a preset inclined direction, so that each group of flying capacitors 10 and the current conversion tube in the second current conversion unit 5 to which it belongs have a sufficiently short routing length, thereby reducing the loop area of ​​the overall circuit and reducing the electromagnetic interference between different electrical devices on the circuit substrate 1.

[0066] In addition, a capacitor module 12 is provided on the second surface of the circuit substrate 1. The capacitor module 12 is used as a bus capacitor to connect the first current conversion unit 4 and the second current conversion unit 5. Figure 6 C2 and C3 in the circuit. The capacitor module 12 includes a first capacitor unit 13 and a second capacitor unit 14; the first capacitor unit 13 is located between the first current conversion unit 4 and the second current conversion unit 5; the second capacitor unit 14 is located in the middle position in the left-right direction of the circuit substrate 1, extending between the two flying units 11 and corresponding to the area in the second current conversion module 3 where no current conversion tube is provided. It should be noted that the first capacitor unit 13 and the second capacitor unit 14 here are divided according to the position of the capacitor, rather than the circuit structure. The first capacitor unit 13 and the second capacitor unit 14 do not correspond to C2 and C3. Refer to Figure 2The first capacitor unit 13 refers to a group of capacitors arranged in the left-right direction and located at the upper position, and the second capacitor unit 14 refers to a capacitor located below the first capacitor unit 13 and not only arranged in the left-right direction, but also arranged in a stepped manner in the up-down direction. The second capacitor unit 14 extends into the position between the two flying units 11, and its shape also corresponds to the space between the second converter unit 5 located on the left part and the right part on the first surface. In this way, the second capacitor unit 14 can be arranged using the space between the two flying units 11 and the space between the second converter units 5 on the left and right sides, thereby reducing the occupied area of ​​the capacitor module 12 in the up-down direction, so that the second converter module 3 has a larger space for arrangement on the circuit substrate 1; and the distance between the second converter unit 5, the flying unit 11 and the capacitor module 12 can be reduced, thereby reducing the high-frequency loop area of ​​the overall circuit and reducing the electromagnetic interference between different electrical devices on the circuit substrate 1.

[0067] Reference Figure 2 In the second converter module 3, a flying circuit board 15 is provided close to the flying unit 11, and a plurality of through holes 16 are provided on the flying circuit board 15 for airflow to pass through and for heat dissipation of the second capacitor unit 14 extending between the two flying capacitors 10; the capacitor components of the flying capacitor 10 in the flying unit 11 are spaced apart from each other at positions corresponding to the through holes 16 to avoid the through holes 16; a plurality of flying diodes 17 connecting the flying capacitor 10 and the capacitor module 12 are also provided on the flying circuit board 15, and at least part of the flying diodes 17 are arranged across the through holes 16 and their projection shape on the projection plane perpendicular to the axial direction of the through holes 16 is staggered with the projection shape of the through holes 16. The flying diode 17 here refers to Figure 6 D3 in the circuit is fixed on the second surface of the circuit substrate 1 by flying across the circuit board 15. Figure 4 The pins of the flying capacitor 10 are welded on the flying circuit board 15, and the flying diode 17 is also welded on the flying circuit board 15, wherein the flying capacitor 10 is separated by the through hole 16 to form a spaced layout so that the through hole 16 can pass the airflow; at the same time, the flying diode 17 is arranged across the through hole 16, and the shape and size of the flying diode 17 will not cover the through hole 16, but will enable the airflow of the through hole 16 to directly contact the heat dissipation surface of the flying diode 17, thereby taking away the heat of the flying diode 17.

[0068] In particular, a spoiler fan may be provided inside the photovoltaic inverter, and the spoiler fan is used to supply air and dissipate heat to the components on the second surface of the circuit substrate 1 of the power component. Figure 2 , Figure 2The parallel arrows in the figure are the air supply directions of the spoiler fan. The spoiler fan is generally arranged outside the power component, so its wind flow will be blocked by the flyover unit 11 which is higher than the circuit substrate 1. In this embodiment, a through hole 16 is arranged on the flyover circuit board 15, so that the wind of the spoiler fan can pass through the through hole 16 to dissipate the heat of the second capacitor unit 14 between the two flyover units 11. At the same time, the heat dissipation efficiency of the second capacitor unit 14 between the two flyover units 11 is improved when the flyover unit 11 is inclined to cause a small windward angle and insufficient windward area.

[0069] Example 2

[0070] Reference Figure 5 , Embodiment 2 of the present invention also provides a photovoltaic inverter, which differs from Embodiment 1 in that, in the power components of the photovoltaic inverter, the multiple second current conversion units 5 located at the same outer position, except for the outermost current conversion tube, are arranged in an inclined direction from top to bottom and from outside to inside. Specifically, the current conversion tube located at the outermost side is arranged vertically in the up-down direction, while the current conversion tube located at the inner side is arranged in a preset inclined direction. Since the high-loss tube is located at the outer position, it is relatively far away from the first current conversion unit 4 located in the middle position, so the heat dissipation efficiency of the first current conversion module 2 can also be improved.

[0071] Of course, in other embodiments, the outermost variable flow tubes and the middle variable flow tubes can be arranged vertically in the up-down direction, and only the innermost variable flow tubes can be arranged in an inclined manner, which can also improve the heat dissipation efficiency of the first variable flow module 2 to a certain extent. Of course, compared with embodiment 1, the above layout methods will reduce the effect of improving the heat dissipation efficiency.

[0072] The description of the above specification and embodiments is used to explain the protection scope of the present invention, but does not constitute a limitation on the protection scope of the present invention. Through the enlightenment of the present invention or the above embodiments, ordinary technicians in this field can obtain modifications, equivalent substitutions or other improvements to the embodiments of the present invention or part of the technical features thereof through logical analysis, reasoning or limited experiments, which should be included in the protection scope of the present invention.

Claims

1. A photovoltaic inverter, characterized in that: include: A power component, comprising a circuit substrate (1), a first current conversion module (2) and a second current conversion module (3) arranged on the circuit substrate (1), and being used to realize inversion and boost functions through the first current conversion module (2) and the second current conversion module (3); A heat sink, the heat dissipation surface of which is in contact with the first converter module (2) and the second converter module (3) on the power component, and the heat dissipation fins (22) of the heat sink extend in the up-down direction and are arranged side by side in the left-right direction; and A cooling fan, located at the lower side of the radiator and adapted to supply air toward the radiator in an up-down direction; In the power component, the first current conversion module (2) and the second current conversion module (3) both form corresponding first current conversion units (4) and second current conversion units (5) through a plurality of semiconductor switch devices arranged on a first surface of a circuit substrate (1), wherein the first current conversion module (2) is located above the second current conversion module (3), and the first current conversion units (4) in the first current conversion module (2) are arranged in sequence along the left-right direction; The middle position of the circuit substrate (1) in the left-right direction is defined as the inner side, and the positions on both sides are defined as the outer side; The second current conversion unit (5) comprises a plurality of current conversion tubes formed by semiconductor switch devices, and the current conversion tubes of each second current conversion unit (5) are arranged in sequence from the outside to the inside of the circuit substrate (1), and from the outside to the inside, the current conversion tube located closer to the inside is farther away from the first current conversion module (2) than another adjacent current conversion tube located closer to the outside; The second current conversion units (5) belonging to the same outer position are arranged in sequence in the up-down direction in a manner that the respective current conversion tubes correspond to each other, and at least one group of multiple current conversion tubes located on the inner side and belonging to different second current conversion units (5) are arranged in an inclined direction from top to bottom and from outside to inside; The current-converting tube components used in the second current-converting unit (5) all include at least one wafer component (18) for switching a circuit on and off, the wafer component (18) being rectangular in shape, and the arrangement direction of the current-converting tube components being configured to be suitable for the long side of the wafer component (18) inside thereof to have an angle relative to the up-down direction; The spacing between the heat dissipation fins (22) on the heat sink is configured to be suitable for allowing the long side of the projection of each wafer component (18) on the plane of the circuit substrate (1) to span across at least two of the heat dissipation fins (22).

2. A photovoltaic inverter as claimed in claim 1, characterized in that: The arrangement direction of at least part of the current conversion tubes used in the second current conversion unit (5) is configured to be suitable for making the long side of the wafer component (18) inside it perpendicular to the up-down direction.

3. A photovoltaic inverter as claimed in claim 1 or 2, characterized in that: The shape of the current converter used in the second current converter unit (5) is rectangular, and the current converter whose arrangement direction is such that the width direction is perpendicular to the left-right direction of the circuit substrate (1) is defined as a type of tube (19), and the long side of the wafer component (18) in the type of tube (19) is perpendicular to the width direction of the current converter to which it belongs.

4. A photovoltaic inverter as claimed in claim 3, characterized in that: The variable current tube components arranged in a direction such that the length direction is perpendicular to the left-right direction of the circuit substrate (1) are second-class tube components (20), and the long sides of the wafer components (18) in the second-class tube components (20) are perpendicular to the length direction of the variable current tube components to which they belong.

5. A photovoltaic inverter as claimed in claim 4, characterized in that: The variable current tube components (21) are arranged in a direction such that the length direction obliquely intersects with the left-right direction of the circuit substrate (1), and the long sides of the wafer components (18) in the three-type tube components (21) are perpendicular to the width direction of the variable current tube components to which they belong.

6. A photovoltaic inverter as claimed in claim 5, characterized in that: The arrangement directions of the plurality of second current conversion units (5) belonging to the same outer position, except for the outermost current conversion tube, are all inclined from top to bottom and from outside to inside.

7. A power component as claimed in claim 5, characterized in that: The arrangement directions of the corresponding flow-converting tubes of the plurality of second flow-converting units (5) belonging to the same outer position at the upper and lower positions are all inclined from top to bottom and from outside to inside.

8. A power component as claimed in claim 6 or 7, characterized in that: The types of the current conversion tubes include high-loss tubes and low-loss tubes. In the same second current conversion unit (5), the high-loss tubes are located outside the circuit substrate (1) relative to the low-loss tubes.

9. A power component as claimed in claim 6 or 7, characterized in that: The first current conversion module (2) comprises three first current conversion units (4) arranged in sequence at a preset distance in the left-right direction, and the boundary between the high-loss pipe and the low-loss pipe in each second current conversion unit (5) corresponds to the boundary between the first current conversion unit (4) located in the middle position and the two second current conversion units (5) located at the two side positions.

10. A power component as claimed in claim 8, characterized in that: The high-loss tube component is a switch tube component that is controlled to open and close, and the low-loss tube component is a diode component used to control the direction of current. Each second current conversion unit (5) includes two groups of switch tube components and two groups of diode components. Each group or every two groups of switch tube components and diode components are suitable for being arranged on the circuit substrate (1) as the current conversion tube component.

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