Photovoltaic inverter and temperature detection device

Abstract

The utility model provides a photovoltaic inverter and a temperature detection device. The photovoltaic inverter comprises a plurality of photovoltaic terminals, a converter, a PCB, a temperature detection circuit and a controller. The plurality of photovoltaic terminals are correspondingly connected with the plurality of photovoltaic modules; the PCB comprises a conductive layer and at least one insulating heat conduction layer, one end of each photovoltaic terminal is welded on the PCB, and the other end of each photovoltaic terminal is in heat conduction connection with the corresponding photovoltaic module; the conductive layer transmits electric energy generated by the plurality of photovoltaic modules to the converter, and each insulating heat conduction layer conducts heat generated by at least one photovoltaic terminal; the temperature detection circuit detects the temperature of each insulating heat-conducting layer; and the controller obtains the temperature of each photovoltaic terminal in the plurality of photovoltaic terminals according to the temperature of each insulating heat-conducting layer. The temperature of the photovoltaic terminal is detected through the temperature detection circuit, and the actual temperature of the photovoltaic terminal can be monitored in real time before the photovoltaic terminal is on fire, so that the reliability of the whole photovoltaic power generation is ensured.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on November 30, 2022, with application number 202211527833.4 and application name “A Photovoltaic Inverter and Temperature Detection Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] 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

[0004] Photovoltaic power generation is a technology that converts sunlight into electricity by utilizing the photovoltaic effect at semiconductor interfaces. A photovoltaic system typically includes photovoltaic modules, photovoltaic terminals, inverters, and AC power distribution equipment. PV modules are typically mounted on a photovoltaic support fixed to the ground to generate electricity in a fixed location. To achieve high output voltage or current, a photovoltaic unit is typically composed of multiple PV modules connected in series or parallel to form a photovoltaic string.

[0005] Currently, photovoltaic modules are connected to photovoltaic inverters or photovoltaic DC combiner boxes through photovoltaic terminals (also known as connectors). The photovoltaic terminals transmit the current output by the photovoltaic modules to the photovoltaic inverter or photovoltaic DC combiner box through reliable electrical connections, thereby achieving current inversion and allowing the electric energy to reach end users or be incorporated into the power grid. The wiring process of existing photovoltaic terminals is specifically as follows: after stripping the cable, use a special tool for the cable to crimp the cable to both sides of the photovoltaic terminal. 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, and even aging and fire.

[0006] Currently, there is still no implementation plan for temperature detection of the 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 the photovoltaic terminals in real time before a fire occurs in the photovoltaic terminals, thereby ensuring the reliability of power generation of the entire system. Summary of the Invention

[0007] 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 to monitor the actual temperature of the photovoltaic terminal in real time before a fire occurs at the photovoltaic terminal, thereby ensuring the reliability of power generation of the entire photovoltaic inverter.

[0008] 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 multiple photovoltaic modules are used to connect to the corresponding multiple photovoltaic terminals; the PCB circuit board includes a conductive layer and at least one insulating thermal conductive layer, one end of each photovoltaic terminal is welded to 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 based on the temperature of each insulating thermal conductive layer.

[0009] By using 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 finally be conducted to the temperature detection circuit; by detecting the temperature of each insulating heat-conducting layer, the temperature of each photovoltaic terminal among the multiple photovoltaic terminals can be obtained, thereby avoiding the problem of aging, overheating and fire caused by poor crimping of the photovoltaic terminals.

[0010] As a possible implementation, between each photovoltaic terminal and the temperature detection circuit, the PCB circuit board includes a plurality of solder points 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 soldered to the PCB circuit board to form a plurality of solder points, and each layer of the insulating heat conductive layer is used to connect to at least one solder point, thereby forming a heat conduction path formed by the solder points formed by the photovoltaic terminal and the PCB circuit board and the insulating heat conductive layer, so that the temperature detection circuit can determine 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.

[0011] 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.

[0012] As a possible implementation, the thermal conductive material forms a thermal conductive layer, the insulating material forms an insulating layer, and insulating layers are laminated on the upper and lower surfaces of the thermal conductive layer to form an insulating thermal conductive layer. The insulating layer covers and adheres to the laminated thermal conductive layer.

[0013] Because multiple photovoltaic terminals and converters are respectively arranged on both sides of a PCB circuit board, if only one temperature detection circuit is provided, it is easily affected by the external ambient temperature, resulting in temperature detection errors. As a possible implementation, the temperature detection circuit specifically includes a first temperature detection circuit and a second temperature detection circuit, and the multiple photovoltaic terminals and converters are arranged on both sides of the PCB circuit board; the PCB circuit board includes a first insulating thermally conductive layer and a second insulating thermally conductive layer, the first insulating thermally conductive layer being closer to the converter side and the second insulating thermally conductive layer being closer to the photovoltaic terminal side; the first temperature detection circuit is used to detect the temperature of the first insulating thermally conductive layer; the second temperature detection circuit is used to detect the temperature of the second insulating thermally conductive layer; and the controller is used to obtain the temperature of each of the multiple photovoltaic terminals based on the temperatures of the first insulating thermally conductive layer and the second insulating thermally conductive layer.

[0014] The heat conduction path between the photovoltaic terminal and the first or second temperature detection circuit can be: photovoltaic terminal (connection point) - solder joint formed by the photovoltaic terminal and the PCB - first temperature detection circuit - second temperature detection circuit. This design simplifies and facilitates the overall temperature detection circuit design, and temperature detection through the first and second temperature detection circuits is more accurate.

[0015] 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.

[0016] 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 the multiple photovoltaic terminals to the PCB circuit board, the multiple photovoltaic terminals can be fixed on the mounting panel first, so as to locate the layout positions of the multiple photovoltaic terminals, thereby facilitating the welding between the photovoltaic terminals and the PCB circuit board. After the photovoltaic terminals are welded to the PCB circuit board, the overall structure consisting of the photovoltaic terminals, the PCB circuit board and the mounting panel is installed in the notch of the outer shell structure.

[0017] As a possible implementation, a sealant or baffle is placed in the gap between the photovoltaic terminal and the through-hole to create a sealed environment within the housing structure. Because cooling devices, such as fans, are present within the housing structure, to minimize the fan's impact on the temperature measurement of the PCB and temperature detection circuit, a sealant or baffle is placed in the gap between the photovoltaic terminal and the through-hole to create a sealed environment within the housing structure.

[0018] As a possible implementation manner, 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 to 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 and the cable end terminal are connected, the first conductive core and the second conductive core establish an electrical connection, so that the output current of the photovoltaic module is input into the converter through the photovoltaic terminal.

[0019] In order to reduce heat loss on the heat conduction path, as a possible implementation method, 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.

[0020] The terminal plug-in temperature detection circuit is located in close proximity to the photovoltaic terminals, significantly reducing heat loss along the conduction path and maximizing the reflection of the photovoltaic terminal temperature, thereby ensuring more accurate temperature protection. The terminal plug-in temperature detection circuit is located at the junction of the board-end terminal and the cable-end terminal in the corresponding photovoltaic terminal to detect the temperature of the photovoltaic terminal.

[0021] In addition, as a possible implementation method, 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 the circuit with larger current, so as to reduce the problem of errors in temperature detection caused by heat caused by thermal effects.

[0022] If the temperature detection circuit is inevitably placed in a circuit with a large current flow, adding grooves or protrusions to the circuit can also reduce the problem of self-heating on the PCB circuit board. The current flow heating problem can also be reduced by increasing the width of the conductive material in the area with large current flow.

[0023] In the second aspect, the present application provides a temperature detection device, which is used in 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 a converter. The multiple photovoltaic terminals are used to connect to multiple photovoltaic modules; 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 converter, 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.

[0024] These and other aspects of the present application will become more readily apparent from the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the structure of a photovoltaic inverter Figure 1 ;

[0026] Figure 2 Schematic diagram of the heat conduction path between the photovoltaic terminal and the temperature detection circuit;

[0027] Figure 3 A schematic diagram of the structure of a photovoltaic inverter Figure 2 ;

[0028] Figure 4 A schematic diagram of a shell structure;

[0029] Figure 5 A schematic diagram of the structure of a photovoltaic terminal Figure 1 ;

[0030] Figure 6 A schematic diagram of the structure of a photovoltaic terminal Figure 2 . DETAILED DESCRIPTION

[0031] 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 with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be understood as being limited to the embodiments set forth 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 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 can be made as needed, and all changes are included in the scope of protection of this application. The drawings in this application are only used to illustrate relative position relationships and do not represent true proportions.

[0032] 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 with reference to the accompanying drawings. The specific operating methods in the method embodiments can also be applied to device embodiments or system embodiments. 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 embodiments of the present invention. "And / or" describes the association relationship of 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 previous and next associated objects 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.

[0033] 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, the connection between A and B can be either a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components. For example, the connection between A and B can also be a direct connection between A and C, and C and B can be directly connected, with A and B connected through C.

[0034] A photovoltaic system generally consists of photovoltaic modules on the DC side forming 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 inverter converts the DC power generated by the photovoltaic modules into AC power and connects it to the power grid, completing the photovoltaic power generation process.

[0035] 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 problem is the fire problem caused by photovoltaic systems, which may cause huge losses to life and property.

[0036] There are many causes of fires in photovoltaic systems, including fires caused by the hot spot effect in photovoltaic modules. The hot spot effect occurs when a photovoltaic module is shaded. The shaded module in the same series branch acts as a load, consuming the energy generated by other illuminated modules. Consequently, the shaded module also heats up, increasing the local current and voltage within the module, causing a local temperature rise in the module and potentially causing spontaneous combustion.

[0037] For example, if the cable connected to the photovoltaic terminal is poorly crimped, it is easy to cause excessive contact resistance, resulting in DC arc heating or even aging and fire. Alternatively, when the cable connected to the photovoltaic terminal is welded to the inverter or photovoltaic module, if the soldering point area is too small, it will also lead to increased resistance and cause fire.

[0038] 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 converters. 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.

[0039] See 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 accordingly.

[0040] PCB 105 comprises a conductive layer 1051 and at least one insulating and thermally conductive layer 1052. One end of each photovoltaic terminal 103 is soldered to PCB 105, and the other end is thermally connected to the corresponding photovoltaic module 102. Conductive layer 1051 transmits the electrical energy generated by each photovoltaic module 102 to inverter 104. Each insulating and thermally conductive layer 1052 conducts heat generated by at least one photovoltaic terminal 103.

[0041] 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 in the plurality of photovoltaic terminals 103 according to the temperature of each insulating heat-conducting layer 1052 .

[0042] The photovoltaic module 102 converts solar energy into electrical energy through the photovoltaic effect, and the converter 104 converts the electrical energy output by the photovoltaic module 102 into appropriate alternating current or direct current to supply the grid or load.

[0043] 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.

[0044] PCB 105 may be any suitable type of PCB, such as a multilayer board, a flexible PCB, a rigid PCB, or a rigid-flex PCB. Conductive layer 1051 may be a copper busbar, an aluminum busbar, a copper-clad aluminum busbar, or a layer made of copper and / or aluminum. It may also be a conductive busbar, conductive sheet, or layer made of other conductive materials, without specific limitation herein.

[0045] 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 ceramic, glass, and a composite material composed of any two or more of these materials. 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) laminate or an active metal bonding copper (AMB) laminate, etc.

[0046] An insulating layer is laminated on the upper and lower surfaces of the thermally conductive layer, and the insulating layer covers and adheres to the laminated thermally conductive layer to form an insulating thermally conductive layer. The PCB circuit board 105 may also include multiple adhesive layers, which can be respectively arranged between the conductive layer 1051 and the insulating thermally conductive layer 1052 to bond the conductive layer 1051 and the insulating thermally conductive layer 1052 together. The adhesive layer can be formed of acrylic glue or epoxy resin glue, or can also be formed of other suitable adhesive materials. In addition, other auxiliary fixing means can also be provided, such as providing a clamping component to fix multiple different material layers in the PCB circuit board 105 together, which is not specifically limited here.

[0047] The temperature detection circuit 106 may include a temperature detection device such as a thermistor or an infrared temperature detection sensor. 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. Furthermore, multiple temperature detection circuits 106 may be provided to detect the temperature of each insulating thermally conductive layer 1052.

[0048] The controller 107 can 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 device, a transistor logic device, a hardware component or any combination thereof. It can implement or execute the various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of this application. The above-mentioned processor can also be a combination that implements computing functions, 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 can 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.

[0049] The photovoltaic terminals 103 are connected to cables at both ends, which in turn are connected to the photovoltaic modules 102 and the inverter 104. Specifically, after stripping the cables, a professional crimping tool can be used to connect the stripped cables to the ends of the photovoltaic terminals 103. Poor crimping of the cables to the photovoltaic terminals 103 can, at best, affect the DC side internal resistance, reducing the power generation efficiency of the photovoltaic inverter 101. In worse cases, poor contact can cause heating or even burn of the photovoltaic terminals 103, which in turn can damage the inverter 104. In more serious cases, it can even lead to a large-scale fire.

[0050] The photovoltaic terminal 103 should be installed in a location that is protected from sunlight and rain, thereby preventing the interface in the photovoltaic terminal 103 from aging or the cable from rusting. 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, there are more and more accidents in which the photovoltaic terminal 103 melts, burns, or even causes the converter 104 to burn out. 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.

[0051] See Figure 2 As shown, Figure 2Figure 1 is a schematic diagram of the thermal path between photovoltaic terminals and the temperature detection circuit. Each photovoltaic terminal 103 is soldered to a PCB 105, forming multiple solder joints. The PCB 105 includes multiple solder joints connecting the photovoltaic terminals 103 to the PCB 105, as well as a thermal path formed by the insulating thermal conductive layer 105. This allows the temperature detection circuit 106 to detect the temperature of each photovoltaic terminal 103 by detecting different layers of the insulating thermal conductive layer 1052. This design significantly reduces the number of temperature detection circuits 106, thereby reducing temperature detection costs.

[0052] Since the 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 provided, 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 converter 104 , and the second insulating heat-conducting layer 105222 is close to the photovoltaic terminal 103 .

[0053] 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 based on the temperatures of the first insulating thermal conductive layer 10521 and the second insulating thermal conductive layer 10522.

[0054] Among them, since the cable crimped to 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.

[0055] 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 (connection point) - the solder joint formed by the photovoltaic terminal 103 and the PCB circuit board 105 - the first temperature detection circuit 1061 / the second temperature detection circuit 1062. With this design, the overall design of the temperature detection circuit 106 is simple and feasible, and temperature detection through the first temperature detection circuit 1061 and the second temperature detection circuit 1062 is more accurate.

[0056] See 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, the converter 103 is placed inside the housing structure 400 ( Figure 4 (not shown), 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.

[0057] During specific installation, the outer shell structure 400 and the mounting panel 401 can be fixedly connected by welding, bonding, screws, etc. Alternatively, in some possible implementations, the outer shell structure 400 and the mounting panel 401 can also be an integral structure. For example, the mounting panel 401 can be formed by die-casting, stamping, etc., so as to make the outer shell structure 400 and the mounting panel 401 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 on the mounting panel 401 first, so as to locate the layout positions of the plurality of photovoltaic terminals 103, so as to facilitate welding between the photovoltaic terminals 103 and the PCB circuit board 105. After the photovoltaic terminals 103 and the PCB circuit board 105 are welded, the overall structure consisting of the photovoltaic terminals 103, the PCB circuit board 105 and the mounting panel 401 is installed in the notch 402 of the outer shell structure 400.

[0058] 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.

[0059] 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 end terminal 1031, a cable end 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 end terminal 1031 has a channel running through both ends thereof, the first conductive core 1033 is slidably disposed in the channel of the board end 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 to the PCB circuit board 105; the cable end terminal 1032 has a channel running through both ends thereof, the second conductive core 1034 is slidably disposed in the channel of the cable end 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.

[0060] 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, the terminal plug temperature detection circuit 601 is provided at the connection between the board terminal 1031 and the cable terminal 1032 in the photovoltaic terminal, for detecting the temperature of the photovoltaic terminal 103.

[0061] The terminal plug temperature detection circuit 601 is located in close proximity to the photovoltaic terminal 103, significantly reducing heat loss along the conduction path and providing maximum visibility into the temperature of the photovoltaic terminal 103, thereby ensuring more precise temperature protection. The terminal plug temperature detection circuit 601 is located at the junction of the board terminal 1031 and the cable terminal 1032 of the corresponding photovoltaic terminal 103 to detect the temperature of the photovoltaic terminal 103.

[0062] In addition, as a possible implementation method, 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.

[0063] If the temperature detection circuit 106 inevitably needs to be 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. The current flow heating problem can also be reduced by increasing the width of the conductive material in the area with larger current flow.

[0064] By using 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 finally be conducted to the temperature detection circuit; by detecting the temperature of each insulating heat-conducting layer, the temperature of each photovoltaic terminal among the multiple photovoltaic terminals can be obtained, thereby avoiding the problem of aging, overheating and fire caused by poor crimping of the photovoltaic terminals.

[0065] 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 a converter. The multiple photovoltaic terminals are used to connect to multiple photovoltaic modules; the PCB circuit board includes a conductive layer and at least one insulating thermal conductive layer. One end of each photovoltaic terminal is welded to 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 converter, 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.

[0066] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A photovoltaic inverter, characterized in that: The photovoltaic inverter comprises: A plurality of photovoltaic terminals, a converter, a PCB circuit board, a temperature detection circuit, and a controller, wherein 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 welded to the PCB circuit board, and the other end is thermally connected to the corresponding photovoltaic module. The conductive layer is used to transmit the electrical energy generated by the plurality of photovoltaic modules to the converter, and each insulating thermal conductive layer is used to conduct heat generated by at least one photovoltaic terminal; The temperature detection circuit is used to detect the temperature of each insulating and heat-conducting layer; The controller is used to monitor the actual temperature of the photovoltaic terminal according to the temperature of each insulating and 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 solder joints connecting the photovoltaic terminals and the PCB circuit board and a heat conduction path formed by the insulating heat conductive layer.

3. The photovoltaic inverter according to claim 1 or 2, characterized in that: Each insulating heat-conducting layer includes a heat-conducting material, and the heat-conducting material is covered by an insulating material.

4. The photovoltaic inverter according to claim 3, characterized in that: The thermal conductive material is composed of one or more of graphite, copper foil or aluminum foil.

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 4, 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 any one of claims 1 to 6, characterized in that: The temperature detection circuit specifically includes a first temperature detection circuit and a second temperature detection circuit. The multiple 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 insulating heat-conducting layer is close to the converter side, and the second insulating heat-conducting layer is close to the multiple photovoltaic terminals 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 configured to obtain a temperature of each 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 any one of claims 1 to 7, characterized in that: 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, the mounting panel is used to be mounted on the shell structure and block the notch, and the mounting panel is provided with a through hole for each photovoltaic terminal to pass through, one end of each photovoltaic terminal is connected to the PCB circuit board inside the shell, and the other end passes through the corresponding through hole and is electrically connected to the corresponding photovoltaic component, so that the detection circuit arranged in the shell and embedded on the circuit board can detect the temperature of the photovoltaic terminal.

9. The photovoltaic inverter according to claim 8, characterized in that: A sealant or a baffle is provided in the gap between the photovoltaic terminal and the through hole, so as to form a sealed environment inside the shell structure.

10. The photovoltaic inverter according to any one of claims 1 to 9, 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 welded 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 further includes a terminal plugging temperature detection circuit, which is arranged at the plugging point between the board end terminal and the cable end terminal in the photovoltaic terminal and is used to detect the temperature at the plugging point of the photovoltaic terminal.

12. A temperature detection device, characterized in that: 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 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 at least one insulating heat-conducting layer. One end of each photovoltaic terminal is welded to the PCB circuit board, and the other end is thermally connected to the corresponding photovoltaic module. The conductive layer is used to transmit the electrical energy generated by the plurality of photovoltaic modules to the converter, and each insulating thermal conductive layer is used to conduct heat generated by at least one photovoltaic terminal; The temperature detection circuit is used to detect the temperature of each insulating heat-conducting layer.

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