Photovoltaic inverter and temperature detection device

Abstract

A photovoltaic inverter and a temperature detection device, the photovoltaic inverter includes a plurality of photovoltaic terminals, a converter, a PCB circuit board, a temperature detection circuit and a controller; the plurality of photovoltaic terminals are used to connect to a plurality of photovoltaic modules; the PCB circuit board includes a conductive layer and at least one insulating heat-conducting layer, one end of each photovoltaic terminal is connected to the PCB circuit board, and the other end is connected to the corresponding photovoltaic module; the conductive layer is used to transmit the electric energy generated by the plurality of photovoltaic modules to the converter, and each insulating heat-conducting layer is used to conduct the heat generated by at least one photovoltaic terminal; the temperature detection circuit is used to detect the temperature of each insulating heat-conducting layer; the controller is used to obtain the temperature of each photovoltaic terminal in the plurality of photovoltaic terminals according to the temperature of each insulating heat-conducting layer. By detecting the temperature of the photovoltaic terminal through the temperature detection circuit, the actual temperature of the photovoltaic terminal can be monitored in real time before the photovoltaic terminal catches fire, thereby ensuring the reliability of the entire photovoltaic power generation.

Description

[0001] This application is a divisional application. The application number of the original application is 202211527833.4, and the original application date is November 30, 2022. The entire contents of the original application are incorporated into this application by reference. Technical Field

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

[0003] Photovoltaic power generation is a technology that uses the photovoltaic effect of semiconductor interfaces to convert light energy into electrical energy. Photovoltaic systems usually include photovoltaic modules, photovoltaic terminals, inverters, AC power distribution equipment, etc. Among them, photovoltaic modules are usually installed on photovoltaic brackets fixed to the ground to generate electricity in a fixed place. In order to obtain a higher output voltage or output current, photovoltaic units are usually composed of multiple photovoltaic modules in a certain series-parallel manner to form a photovoltaic string.

[0004] At present, photovoltaic modules are connected to photovoltaic inverters or photovoltaic DC combiner boxes through photovoltaic terminals (also known as connectors). Photovoltaic terminals transmit the current output by photovoltaic modules to the inside of photovoltaic inverters or photovoltaic DC combiner boxes through reliable electrical connections, thereby achieving current inversion so that electric energy can enter end users or be incorporated into the power grid. The wiring process of existing photovoltaic terminals is as follows: after stripping the cable, use special tools for cables to crimp the cables to both sides of the photovoltaic terminal respectively, one side of the cable is connected to the photovoltaic module, and the other side of the cable is connected to the photovoltaic inverter or photovoltaic DC combiner box. Among them, when the photovoltaic terminal and the cable are poorly crimped, it is easy to cause excessive contact resistance, heating, or even aging and fire.

[0005] At present, there is still no implementation plan for temperature detection of photovoltaic terminals connected between photovoltaic modules and inverters. In view of this, it is necessary to design a photovoltaic inverter to monitor the actual temperature of photovoltaic terminals in real time before a fire occurs at the photovoltaic terminals, so as to ensure the reliability of power generation of the entire system. Summary of the invention

[0006] The present application provides a photovoltaic inverter and a temperature detection device, which detect the temperature of the photovoltaic terminal through a temperature detection circuit, so as to monitor the actual temperature of the photovoltaic terminal in real time before the photovoltaic terminal catches fire, thereby ensuring the reliability of power generation of the entire photovoltaic inverter.

[0007] In a first aspect, the present application provides a photovoltaic inverter, which includes: multiple photovoltaic terminals, an inverter, a PCB circuit board, a temperature detection circuit and a controller, wherein the multiple photovoltaic modules are used to connect to the multiple photovoltaic terminals accordingly; the PCB circuit board includes a conductive layer and at least one insulating thermal conductive layer, one end of each photovoltaic terminal is welded on the PCB circuit board, and the other end is thermally connected to the corresponding photovoltaic module; the conductive layer is used to transmit the electric energy generated by each photovoltaic module to the inverter, and each insulating thermal conductive layer is used to conduct the heat generated by at least one photovoltaic terminal; the temperature detection circuit is used to detect the temperature of each insulating thermal conductive layer; the controller is used to obtain the temperature of each photovoltaic terminal in the multiple photovoltaic terminals according to the temperature of each insulating thermal conductive layer.

[0008] Utilizing the photovoltaic inverter provided in the present application, the heat generated by each photovoltaic terminal can be conducted through at least one insulating heat-conducting layer, and the heat can ultimately be conducted to the temperature detection circuit; the temperature of each photovoltaic terminal among a plurality of photovoltaic terminals can be obtained by detecting the temperature of each insulating heat-conducting layer, thereby avoiding the problem of aging, overheating and fire caused by poor crimping of the photovoltaic terminals.

[0009] As a possible implementation, between each photovoltaic terminal and the temperature detection circuit, the PCB circuit board includes a plurality of solder joints connecting the photovoltaic terminal and the PCB circuit board and a heat conduction path formed by an insulating heat conductive layer. Each photovoltaic terminal is welded to the PCB circuit board to form a plurality of solder joints, and each layer of the insulating heat conductive layer is used to connect to at least one solder joint, thereby forming a solder joint formed by the photovoltaic terminal and the PCB circuit board and a heat conduction path formed by the insulating heat conductive layer, so that the temperature detection circuit determines the temperature of each photovoltaic terminal by detecting different layers of the insulating heat conductive layer. With this design, the number of temperature detection circuits can be significantly reduced, thereby reducing the cost of temperature detection. Each layer of the insulating heat conductive layer includes a heat conductive material, and the heat conductive material is coated with an insulating material.

[0010] As a possible implementation manner, the thermal conductive material is composed of one or more of graphite, copper foil or aluminum foil, and the insulating material is composed of one or more of epoxy resin, silicone rubber, insulating ceramic or glass.

[0011] As a possible implementation, the thermal conductive material forms a thermal conductive layer, the insulating material forms an insulating layer, the upper surface and the lower surface of the thermal conductive layer are respectively laminated with insulating layers to form an insulating thermal conductive layer, and the insulating layer covers and adheres to the laminated thermal conductive layer.

[0012] Since multiple photovoltaic terminals and converters are respectively arranged on both sides of the PCB circuit board, if only one temperature detection circuit is arranged, it is easily affected by the external environment temperature, resulting in the problem of temperature detection error. As a possible implementation, the temperature detection circuit specifically includes a first temperature detection circuit and a second temperature detection circuit, and multiple photovoltaic terminals and converters are arranged on both sides of the PCB circuit board; the PCB circuit board includes a first insulating heat-conducting layer and a second insulating heat-conducting layer, the first insulating heat-conducting layer is close to the converter side, and the second insulating heat-conducting layer is close to the photovoltaic terminal side; the first temperature detection circuit is used to detect the temperature of the first insulating heat-conducting layer; the second temperature detection circuit is used to detect the temperature of the second insulating heat-conducting layer; the controller is used to: obtain the temperature of each photovoltaic terminal in the multiple photovoltaic terminals according to the temperature of the first insulating heat-conducting layer and the second insulating heat-conducting layer.

[0013] The heat conduction path between the photovoltaic terminal and the first temperature detection circuit or the second temperature detection circuit can be: photovoltaic terminal (plug point) - the solder joint formed by the photovoltaic terminal and the PCB circuit board - the first temperature detection circuit and the second temperature detection circuit. With this design, the overall design of the temperature detection circuit is simple and feasible, and the temperature detection is more accurate by performing temperature detection through the first temperature detection circuit and the second temperature detection circuit.

[0014] As a possible implementation, the photovoltaic inverter also includes: a shell structure and a mounting panel, the shell structure is provided with a notch, the converter is placed inside the shell structure, and the mounting panel is provided with a through hole for each photovoltaic terminal to pass through; the mounting panel is used to be installed on the shell structure and seal the notch.

[0015] During specific installation, the outer shell structure and the mounting panel can be fixedly connected by welding, bonding, screws, etc. Alternatively, in some possible implementations, the outer shell structure and the mounting panel can also be an integrated structure. Before welding a plurality of photovoltaic terminals to a PCB circuit board, the plurality of photovoltaic terminals can be first fixed to the mounting panel, so as to locate the layout positions of the plurality of photovoltaic terminals, so as to facilitate welding between the photovoltaic terminals and the PCB circuit board. After welding the photovoltaic terminals to the PCB circuit board, the overall structure consisting of the photovoltaic terminals, the PCB circuit board, and the mounting panel is then installed in the notch of the outer shell structure.

[0016] As a possible implementation, a sealant or a baffle is provided in the gap between the photovoltaic terminal and the through hole to form a closed environment inside the shell structure. Since there are cooling devices such as fans inside the shell structure, in order to reduce the temperature measurement effect of the fan on the PCB circuit board and the temperature detection circuit. A sealant or a baffle is provided in the gap between the photovoltaic terminal and the through hole to form a closed environment inside the shell structure.

[0017] As a possible implementation, each photovoltaic terminal includes a board end terminal, a cable end terminal, a first conductive core, a second conductive core, a first conductive cable and a second conductive cable; the board end terminal has a channel running through both ends thereof, the first conductive core is slidably arranged in the channel of the board end terminal, one end of the first conductive cable is crimped on the first conductive core, and the other end of the first conductive cable is welded on the PCB circuit board; the cable end terminal has a channel running through both ends thereof, the second conductive core is slidably arranged in the channel of the cable end terminal, one end of the second conductive cable is crimped on the second conductive core, and the other end of the second conductive cable is connected to the photovoltaic module; after the board end terminal is connected to the cable end terminal, the first conductive core and the second conductive core are electrically connected, so that the output current of the photovoltaic module is input into the inverter through the photovoltaic terminal.

[0018] In order to reduce heat loss on the heat conduction path, as a possible implementation, the photovoltaic inverter also includes: a terminal plug temperature detection circuit, which is arranged at the connection between the board end terminal and the cable end terminal in the photovoltaic terminal to detect the temperature of the photovoltaic terminal.

[0019] The terminal plug temperature detection circuit is close to the photovoltaic terminal, which can greatly reduce the heat loss on the conduction path and can reflect the temperature of the photovoltaic terminal to the greatest extent, thereby making the temperature protection more accurate. Among them, the terminal plug temperature detection circuit is set at the connection between the board end terminal and the cable end terminal in the corresponding photovoltaic terminal to detect the temperature of the photovoltaic terminal.

[0020] In addition, as a possible implementation, when the temperature detection circuit is set on a PCB circuit board, the location of the temperature detection circuit should be set as far away as possible from circuits with larger currents, so as to reduce the problem of errors in temperature detection caused by heat caused by thermal effects.

[0021] If the temperature detection circuit is inevitably set in a circuit with a larger current flow, the problem of self-heating on the PCB circuit board can also be reduced by adding grooves or protrusions on the circuit. The current flow heating problem can also be reduced by increasing the width of the conductive material in the area with larger current flow.

[0022] In the second aspect, the present application provides a temperature detection device, which is applied to a photovoltaic inverter. The temperature detection device includes a temperature detection circuit, a PCB circuit board and a controller. The photovoltaic inverter includes multiple photovoltaic terminals and an inverter. The multiple photovoltaic terminals are used to connect to multiple photovoltaic components; the PCB circuit board includes a conductive layer and at least one insulating thermal conductive layer. One end of each photovoltaic terminal is welded on the PCB circuit board, and the other end is thermally connected to the corresponding photovoltaic component; the conductive layer is used to transmit the electric energy generated by each photovoltaic component to the inverter, and each insulating thermal conductive layer is used to conduct the heat generated by at least one photovoltaic terminal; the temperature detection circuit is used to detect the temperature of each insulating thermal conductive layer.

[0023] These and other aspects of the present application will become more clearly understood in the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of a photovoltaic inverter Figure 1 ;

[0025] Figure 2 It is a schematic diagram of the heat conduction path between the photovoltaic terminal and the temperature detection circuit;

[0026] Figure 3 A schematic diagram of the structure of a photovoltaic inverter Figure 2 ;

[0027] Figure 4 A schematic diagram of a shell structure;

[0028] Figure 5 A schematic diagram of the structure of a photovoltaic terminal Figure 1 ;

[0029] Figure 6 A schematic diagram of the structure of a photovoltaic terminal Figure 2 . DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as being limited to the embodiments described herein; on the contrary, these embodiments are provided to make the present application more comprehensive and complete, and to fully convey the concepts of the example embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted. The words expressing position and direction described in this application are all explained using the accompanying drawings as examples, but changes may be made as needed, and all changes are included in the scope of protection of this application. The drawings of this application are only used to illustrate the relative position relationship and do not represent the true proportions.

[0031] In order to make the purpose, technical solution and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. The specific operating method in the method embodiment can also be applied to the device embodiment or the system embodiment. It should be noted that in the description of the present application, "at least one" refers to one or more, wherein multiple refers to two or more. In view of this, "multiple" can also be understood as "at least two" in the embodiment of the present application. "And / or" describes the association relationship of the associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the related objects before and after are in an "or" relationship. In addition, it should be understood that in the description of the present application, words such as "first" and "second" are only used to distinguish the purpose of description, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order.

[0032] It should be noted that in the embodiments of the present application, "connection" refers to electrical connection, and the connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, A and B are connected, which can be either A and B directly connected, or A and B indirectly connected through one or more other electrical components, for example, A and B are connected, or A and C are directly connected, C and B are directly connected, and A and B are connected through C.

[0033] A photovoltaic system generally consists of photovoltaic modules on the DC side to form a DC source. The photovoltaic modules are connected to a DC combiner box through photovoltaic terminals. The DC combiner box combines the currents of each module string and connects them to the inverter. The DC power generated by the photovoltaic modules is converted into AC power through the inverter and connected to the power grid to complete the photovoltaic power generation process.

[0034] As the application of photovoltaic power generation becomes more and more widespread, more and more problems of photovoltaic systems are exposed to people. The more serious one is the fire problem caused by photovoltaic systems, which may cause huge losses to life and property.

[0035] There are many reasons for fires in photovoltaic systems, such as fires caused by hot spot effects in photovoltaic modules. The hot spot effect is that when a photovoltaic module is shaded, the shaded photovoltaic module in the same series branch will be treated as a load to consume the energy generated by other illuminated photovoltaic modules. Therefore, the shaded photovoltaic module will also heat up, and the local current and voltage of the photovoltaic module will increase, resulting in a local temperature rise on the photovoltaic module, causing the photovoltaic module to self-ignite.

[0036] For another example: when the cable connected to the photovoltaic terminal is poorly crimped, it is easy to cause excessive contact resistance and generate DC arc heating or even aging and fire. Or, when the cable connected to the photovoltaic terminal is welded to the inverter or photovoltaic module, if the welding point area is too small, it will also cause the resistance to increase and cause a fire.

[0037] Currently, there are some solutions for temperature detection and protection of photovoltaic modules, but there is still no implementation plan for temperature detection of photovoltaic terminals connecting photovoltaic modules and inverters. In view of this, the present application provides a photovoltaic inverter that can monitor the actual temperature of photovoltaic terminals in real time before a fire occurs at the photovoltaic terminals, thereby ensuring the reliability of the entire system.

[0038] See also Figure 1 As shown, Figure 1 A schematic diagram of the structure of a photovoltaic inverter Figure 1 The photovoltaic inverter 101 includes: a plurality of photovoltaic terminals 103 , a converter 104 , a printed circuit board (PCB) 105 , a temperature detection circuit 106 and a controller 107 ; the plurality of photovoltaic terminals 103 are used to connect the plurality of photovoltaic modules 102 .

[0039] The PCB circuit board 105 includes: a conductive layer 1051 and at least one insulating heat-conducting layer 1052. One end of each photovoltaic terminal 103 is welded on the PCB circuit board 105, and the other end is thermally connected to the corresponding photovoltaic module 102. The conductive layer 1051 is used to transmit the electric energy generated by each photovoltaic module 102 to the inverter 104. Each insulating heat-conducting layer 1052 is used to conduct the heat generated by at least one photovoltaic terminal 103.

[0040] The temperature detection circuit 106 is used to detect the temperature of each insulating heat-conducting layer 1052 . The controller 107 is used to obtain the temperature of each photovoltaic terminal 103 among the plurality of photovoltaic terminals 103 according to the temperature of each insulating heat-conducting layer 1052 .

[0041] The photovoltaic module 102 converts solar energy into electrical energy through the photovoltaic effect, and the inverter 104 converts the electrical energy output by the photovoltaic module 102 into appropriate alternating current or direct current to supply the grid or load.

[0042] The photovoltaic module 102 and the converter 104 are connected via a photovoltaic terminal 103 (connector structure). The photovoltaic terminal 103 has very low contact resistance and has properties such as waterproof, high temperature resistant, corrosion resistant, and high insulation.

[0043] The PCB circuit board 105 can be any appropriate type of PCB, such as a multilayer board, a flexible PCB, a rigid PCB, a rigid-flexible PCB, etc. The conductive layer 1051 can be a copper bus, an aluminum bus, a copper-clad aluminum bus, or a layered body made of copper and / or aluminum, or can also be a conductive bus, a conductive sheet, or a layered body made of other conductive materials, which is not specifically limited here.

[0044] The insulating heat-conducting layer 1052 may specifically include an insulating layer and a heat-conducting layer ( Figure 1 The material of the insulating layer includes but is not limited to epoxy resin, silicone rubber, insulating ceramics, glass and other materials, and a composite material composed of any two or more of these materials, etc. The thermal conductive layer can be one or more of graphite, copper foil or aluminum foil, wherein the copper foil can be a direct bonding copper (DBC) or an active metal brazing copper clad laminate (AMB), etc.

[0045] The upper surface and the lower surface of the heat-conducting layer are respectively laminated with an insulating layer, and the insulating layer covers and adheres to the laminated heat-conducting layer to form an insulating heat-conducting layer. The PCB circuit board 105 may also include a plurality of adhesive layers, and the adhesive layers may be respectively arranged between the conductive layer 1051 and the insulating heat-conducting layer 1052 to bond the conductive layer 1051 and the insulating heat-conducting layer 1052 together. The adhesive layers may be formed of acrylic glue or epoxy resin glue, or may also be formed of other appropriate adhesive materials. In addition, other auxiliary fixing means may also be provided, such as providing a clamping component to fix the multiple different material layers in the PCB circuit board 105 together, which is not specifically limited here.

[0046] The temperature detection circuit 106 may include: a temperature detection device such as a thermistor or an infrared temperature detection sensor, and the thermistor may be any of the following: a positive temperature coefficient (PTC) thermistor, whose resistance changes positively with temperature, or a negative temperature coefficient (NTC) thermistor, whose resistance changes negatively with temperature. In addition, a plurality of temperature detection circuits 106 may be provided to detect the temperature of each insulating thermal conductive layer 1052 respectively.

[0047] The controller 107 may be a general-purpose central processing unit (CPU), a general-purpose processor, a digital signal processing (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. It may implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of the present application. The above-mentioned processor may also be a combination for implementing a computing function, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and the like. In addition, the controller 107 may also include an analog to digital converter (ADC) for converting the analog quantity of the input detected by the temperature detection circuit 106 into a digital quantity, thereby determining the temperature of each photovoltaic terminal 103.

[0048] The two ends of the photovoltaic terminal 103 are connected to the cable, and the photovoltaic module 102 and the converter 104 are connected to each other through the cable. Specifically, after the cable is stripped, a professional crimping tool can be used to connect the stripped cable to the two ends of the photovoltaic terminal 103. If the cable is poorly crimped to the photovoltaic terminal 103, it may affect the internal resistance of the DC side, resulting in a decrease in the power generation efficiency of the photovoltaic inverter 101. In severe cases, poor contact may cause the photovoltaic terminal 103 to heat up or even burn, and then the converter 104 may be burned. In more serious cases, it may even cause a large-scale fire.

[0049] The photovoltaic terminal 103 should be installed in a location that is not exposed to sunlight or rain, so as to avoid aging of the interface in the photovoltaic terminal 103 or rust of the cable. However, with the development of photovoltaic technology, the capacity of a single photovoltaic module 102 is getting larger and larger, and its output current is also gradually increasing. During the installation and use of the photovoltaic terminal 103, more and more photovoltaic terminals 103 melt, burn, and even cause the converter 104 to burn. Therefore, the present application performs real-time temperature detection on the photovoltaic terminal 103 through the temperature detection circuit 106, thereby indirectly determining the crimping state of the photovoltaic terminal 103 to ensure that the photovoltaic inverter 101 can work normally.

[0050] See also Figure 2 As shown, Figure 2The figure is a schematic diagram of the heat conduction path between the photovoltaic terminal and the temperature detection circuit, wherein each photovoltaic terminal 103 is welded on the PCB circuit board 105 to form a plurality of welding points, and between each photovoltaic terminal 103 and the temperature detection circuit 106, the PCB circuit board 105 includes a plurality of welding points connecting the photovoltaic terminal 103 and the PCB circuit board 105 and a heat conduction path formed by the insulating heat conductive layer 105, so that the temperature detection circuit 106 can obtain the temperature of each photovoltaic terminal 103 by detecting different layers of the insulating heat conductive layer 1052. With this design, the number of temperature detection circuits 106 can be significantly reduced, thereby reducing the cost of temperature detection.

[0051] Since the plurality of photovoltaic terminals 103 and the converter 104 are respectively arranged on both sides of the PCB circuit board 105, if only one temperature detection circuit 106 is arranged, it is easily affected by the external environment temperature, resulting in the problem of temperature detection error. Figure 3 As shown, Figure 3 A schematic diagram of the structure of a photovoltaic inverter Figure 2 The temperature detection circuit 106 specifically includes a first temperature detection circuit 1061 and a second temperature detection circuit 1062 . The PCB circuit board 105 includes a first insulating heat-conducting layer 10521 and a second insulating heat-conducting layer 10522 . The first insulating heat-conducting layer 10521 is close to the inverter 104 , and the second insulating heat-conducting layer 105222 is close to the photovoltaic terminal 103 .

[0052] The first temperature detection circuit 1061 is used to detect the temperature of the first insulating thermal conductive layer 10521; the second temperature detection circuit 1062 is used to detect the temperature of the second insulating thermal conductive layer 10522; the controller is used to: obtain the temperature of each photovoltaic terminal 103 among the multiple photovoltaic terminals 103 according to the temperatures of the first insulating thermal conductive layer 10521 and the second insulating thermal conductive layer 10522.

[0053] Among them, since the cable crimped with the photovoltaic terminal 103 is soldered to the PCB circuit board 105, the first temperature detection circuit 1061 can detect the temperature of the side where the solder joint is formed between the photovoltaic terminal 103 and the PCB circuit board 105, and the second temperature detection circuit 1062 can detect the temperature of the other side where the solder joint is formed between the photovoltaic terminal 103 and the PCB circuit board 105.

[0054] In this way, the heat conduction path between the photovoltaic terminal 103 and the first temperature detection circuit 1061 or the second temperature detection circuit 1062 can be: photovoltaic terminal 103 (plug point) - solder joint formed by the photovoltaic terminal 103 and the PCB circuit board 105 - first temperature detection circuit 1061 / second temperature detection circuit 1062. With this design, the overall design of the temperature detection circuit 106 is simple and feasible, and the temperature detection is more accurate through the first temperature detection circuit 1061 and the second temperature detection circuit 1062.

[0055] See also Figure 4 As shown, Figure 4 Schematic diagram of a housing structure; the photovoltaic inverter 101 further includes: a housing structure 400 and a mounting panel 401, the housing structure 400 is provided with a notch 402, and the converter 103 is placed inside the housing structure 400 ( Figure 4 (not shown in the figure), the mounting panel 401 is provided with a through hole 403 for each photovoltaic terminal 103 to pass through; the mounting panel 401 is used to be mounted on the outer shell structure 400 and block the gap 402.

[0056] During specific installation, the shell structure 400 and the installation panel 401 can be fixedly connected by welding, bonding, screws, etc. Alternatively, in some possible implementations, the shell structure 400 and the installation panel 401 can also be an integral structure. For example, the installation panel 401 can be formed by die casting, stamping, etc., so that the shell structure 400 and the installation panel 401 are made into an integrally formed structural member. Specifically, before welding a plurality of photovoltaic terminals 103 to the PCB circuit board 105, the plurality of photovoltaic terminals 103 can be fixed to the installation panel 401 first, so as to locate the layout positions of the plurality of photovoltaic terminals 103, so as to facilitate the welding between the photovoltaic terminal 103 and the PCB circuit board 105. After the photovoltaic terminal 103 and the PCB circuit board 105 are welded, the overall structure consisting of the photovoltaic terminal 103, the PCB circuit board 105 and the installation panel 401 is then installed in the notch 402 of the shell structure 400.

[0057] Since there are cooling devices such as fans inside the shell structure 400, in order to reduce the impact of the cooling devices on the temperature measurement of the PCB circuit board and the temperature detection circuit 106, a sealant or baffle can be provided in the gap between the photovoltaic terminal 103 and the through hole to form a closed environment inside the shell structure 400.

[0058] As a possible implementation, see Figure 5 As shown, Figure 5 A schematic diagram of the structure of a photovoltaic terminal Figure 1; Each photovoltaic terminal 103 may specifically include a board terminal 1031, a cable terminal 1032, a first conductive core 1033, a second conductive core 1034, a first conductive cable 1035 and a second conductive cable 1036; the board terminal 1031 has a channel running through both ends thereof, the first conductive core 1033 is slidably disposed in the channel of the board terminal 1031, one end of the first conductive cable 1035 is crimped onto the first conductive core 1033, and the other end of the first conductive cable 1035 is welded onto the PCB circuit board 105; the cable terminal 1032 has a channel running through both ends thereof, the second conductive core 1034 is slidably disposed in the channel of the cable terminal 1032, one end of the second conductive cable 1036 is crimped onto the second conductive core 1034, and the other end of the second conductive cable 1036 is connected to the photovoltaic module 102.

[0059] In order to reduce the heat loss on the heat conduction path, as a possible implementation method, see Figure 6 As shown, Figure 6 A schematic diagram of the structure of a photovoltaic terminal Figure 2 The photovoltaic inverter 101 further includes: a terminal plug temperature detection circuit 601, which is arranged at the connection between the board terminal 1031 and the cable terminal 1032 in the photovoltaic terminal, and is used to detect the temperature of the photovoltaic terminal 103.

[0060] The terminal plug temperature detection circuit 601 is close to the photovoltaic terminal 103, which can greatly reduce the heat loss on the conduction path and can reflect the temperature of the photovoltaic terminal 103 to the greatest extent, thereby making the temperature protection more accurate. The terminal plug temperature detection circuit 601 is set at the connection between the board terminal 1031 and the cable terminal 1032 in the corresponding photovoltaic terminal 103 to detect the temperature of the photovoltaic terminal 103.

[0061] In addition, as a possible implementation, when the temperature detection circuit 106 is set on the PCB circuit board 105, the position of the temperature detection circuit 106 should be set as far away as possible from the circuit with larger current, so as to reduce the problem of errors in temperature detection caused by heat caused by thermal effects.

[0062] If the temperature detection circuit 106 is inevitably set in a circuit with a larger current flow, the problem of self-heating on the PCB circuit board 105 can also be reduced by adding grooves or protrusions on the circuit, and the current flow heating problem can also be reduced by increasing the width of the conductive material in the area with larger current flow.

[0063] Utilizing the photovoltaic inverter provided in the present application, the heat generated by each photovoltaic terminal can be conducted through at least one insulating heat-conducting layer, and the heat can ultimately be conducted to the temperature detection circuit; the temperature of each photovoltaic terminal among a plurality of photovoltaic terminals can be obtained by detecting the temperature of each insulating heat-conducting layer, thereby avoiding the problem of aging, overheating and fire caused by poor crimping of the photovoltaic terminals.

[0064] Based on the same concept, the present application also provides a temperature detection device, which is applied to the above-mentioned photovoltaic inverter 101. The temperature detection device includes a temperature detection circuit, a PCB circuit board and a controller. The photovoltaic inverter includes multiple photovoltaic terminals and an inverter. The multiple photovoltaic terminals are used to connect multiple photovoltaic components accordingly; the PCB circuit board includes a conductive layer and at least one insulating thermal conductive layer. One end of each photovoltaic terminal is welded on the PCB circuit board, and the other end is thermally connected to the corresponding photovoltaic component; the conductive layer is used to transmit the electric energy generated by each photovoltaic component to the inverter, and each insulating thermal conductive layer is used to conduct the heat generated by at least one photovoltaic terminal; the temperature detection circuit is used to detect the temperature of each insulating thermal conductive layer.

[0065] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A photovoltaic inverter, characterized in that: The photovoltaic inverter comprises: A plurality of photovoltaic terminals, a converter, a PCB circuit board, a temperature detection circuit, a housing structure, a mounting panel and a controller, wherein the plurality of photovoltaic terminals are used to connect a plurality of photovoltaic modules; The converter and the PCB circuit board are placed inside the housing structure, the mounting panel is on the housing structure, and the mounting panel is provided with a through hole for the photovoltaic terminal to pass through; The PCB circuit board includes a conductive layer and one or more insulating heat-conducting layers, one end of each photovoltaic terminal is located inside the shell structure and connected to the PCB circuit board, and the other end is located outside the shell structure and conductively connected to the corresponding photovoltaic module; The conductive layer is used to transmit the electric energy generated by the plurality of photovoltaic modules to the converter; The one or more insulating heat-conducting layers are respectively thermally connected to the one or more photovoltaic terminals, and are used to conduct heat generated by at least one photovoltaic terminal; The temperature detection circuit is arranged on the PCB circuit board and is thermally connected to the one or more insulating heat-conducting layers respectively, so as to detect the temperature of the insulating heat-conducting layer correspondingly connected to the photovoltaic terminal; The controller is used to monitor the temperature of each photovoltaic terminal among the plurality of photovoltaic terminals according to the temperature of each insulating heat-conducting layer.

2. The photovoltaic inverter according to claim 1, characterized in that: Between each photovoltaic terminal and the temperature detection circuit, the PCB circuit board includes connection points where the multiple photovoltaic terminals are connected to the PCB circuit board and a heat conduction path formed by the insulating heat-conducting layer.

3. The photovoltaic inverter according to claim 1 or 2, characterized in that: The one or more insulating heat-conducting layers are located between the connection between the one or more photovoltaic terminals and the PCB circuit board and the corresponding temperature detection circuits, and each temperature detection circuit is thermally connected to one or two photovoltaic terminals respectively.

4. The photovoltaic inverter according to claim 1 or 2, characterized in that: The temperature detection circuit is a thermistor type detection circuit, and the thermistors are arranged on the circuit board and are respectively connected to the heat conduction paths formed by the insulating heat conductive layer and the photovoltaic terminals.

5. The photovoltaic inverter according to claim 1 or 2, characterized in that: Each insulating heat-conducting layer includes a heat-conducting material, which is coated with an insulating material. The heat-conducting material is composed of one or more of graphite, copper foil or aluminum foil, and the insulating material is composed of one or more of epoxy resin, silicone rubber, insulating ceramic or glass.

6. The photovoltaic inverter according to claim 5, characterized in that: The thermally conductive material forms a thermally conductive layer, the insulating material forms an insulating layer, the insulating layers are laminated on the upper surface and the lower surface of the thermally conductive layer to form an insulating thermally conductive layer, and the insulating layer covers and adheres to the laminated thermally conductive layer.

7. The photovoltaic inverter according to claim 1 or 2, characterized in that: The temperature detection circuit specifically includes a first temperature detection circuit and a second temperature detection circuit, the plurality of photovoltaic terminals and the converter are respectively arranged on both sides of the PCB circuit board; the PCB circuit board includes a first insulating heat-conducting layer and a second insulating heat-conducting layer; The first temperature detection circuit is used to detect the temperature of the first insulating heat-conducting layer; The second temperature detection circuit is used to detect the temperature of the second insulating heat-conducting layer; The controller is further configured to obtain the temperatures of the plurality of photovoltaic terminals according to the temperatures of the first insulating heat-conducting layer and the second insulating heat-conducting layer.

8. The photovoltaic inverter according to claim 1 or 2, characterized in that: The shell structure is provided with a notch, the inverter is placed inside the shell structure, the mounting panel is used to be mounted on the shell structure and seal the notch, one end of each photovoltaic terminal is connected to the PCB circuit board inside the shell structure by welding, and the other end is electrically connected to the corresponding photovoltaic component through a corresponding through hole, so that the detection circuit inside the shell structure and arranged on the circuit board can detect the temperature of the photovoltaic terminal.

9. The photovoltaic inverter according to claim 1 or 2, characterized in that: One end of each photovoltaic terminal is thermally connected to the PCB circuit board inside the shell structure of the photovoltaic inverter, and the other end is conductively connected to the corresponding photovoltaic component through the corresponding through hole, so that the detection circuit inside the shell structure and arranged on the circuit board detects the temperature of the connection between the other end of the photovoltaic terminal outside the shell structure and the cable, so as to perform real-time temperature detection of the photovoltaic terminal.

10. The photovoltaic inverter according to claim 1 or 2, characterized in that: Each photovoltaic terminal includes a board terminal, a cable terminal, a first conductive core, a second conductive core, a first conductive cable and a second conductive cable; the board terminal has a channel running through both ends thereof, the first conductive core is slidably disposed in the channel of the board terminal, one end of the first conductive cable is crimped onto the first conductive core, and the other end of the first conductive cable is connected to the PCB circuit board; the cable terminal has a channel running through both ends thereof, the second conductive core is slidably disposed in the channel of the cable terminal, one end of the second conductive cable is crimped onto the second conductive core, and the other end of the second conductive cable is connected to the photovoltaic module; After the board-end terminal is connected to the cable-end terminal, the first conductive core is electrically connected to the second conductive core, so that the output current of the photovoltaic assembly is input into the converter through the photovoltaic terminal.

11. The photovoltaic inverter according to claim 10, characterized in that: The photovoltaic inverter also includes: a terminal plug-in temperature detection circuit, which is arranged at the plug-in point between the board end terminal and the cable end terminal in the photovoltaic terminal or on the PCB circuit board, and is used to detect the temperature of the photovoltaic terminal connection point.

12. A temperature detection device, characterized in that: Applied in a photovoltaic inverter, the temperature detection device includes a temperature detection circuit, a PCB circuit board, and a controller. The photovoltaic inverter includes a plurality of photovoltaic terminals and a converter. The plurality of photovoltaic terminals are used to connect to a plurality of photovoltaic modules. The PCB circuit board includes a conductive layer and an insulating heat-conducting layer, one end of each photovoltaic terminal is located inside the inverter and connected to the PCB circuit board, and the other end is located outside the inverter and conductively connected to the corresponding photovoltaic module; The conductive layer is used to transmit the electric energy generated by the plurality of photovoltaic modules to the converter; The insulating heat-conducting layer is used to conduct heat generated by at least one photovoltaic terminal to the temperature detection circuit; The temperature detection circuit is used to detect the temperature of each insulating heat-conducting layer.

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