A method and device for simulating the temperature of a photovoltaic module junction box

Abstract

The present invention discloses a method and device for simulating the temperature of a junction box of a photovoltaic module. The method for simulating the temperature of a junction box of a photovoltaic module comprises: constructing a three-dimensional structure diagram of a junction box to be simulated according to a user instruction; receiving a heat dissipation theoretical model of the junction box input by a user, the heat dissipation theoretical model comprising a temperature parameter and a wind speed parameter; receiving values ​​of other parameters in the heat dissipation theoretical model except the temperature parameter, and a temperature reference condition input by a user; and obtaining a temperature simulation result of the junction box to be simulated according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of the other parameters and the temperature reference condition. The technical solution provided by the embodiment of the present invention improves the accuracy of the simulation result.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of photovoltaic power generation technology, and in particular to a method and device for simulating the temperature of a junction box of a photovoltaic module. Background Art

[0002] Affected by environmental factors and its own factors, high-temperature hot spots are prone to occur during the operation of photovoltaic modules, which can cause the diodes in the junction box to start, the junction box temperature to rise, the junction box to bulge or even burn. Therefore, predicting possible problems and determining corresponding solutions based on the junction box temperature simulation results are important for improving the performance of photovoltaic modules.

[0003] In the prior art, the simulation of the junction box temperature of a photovoltaic module is usually performed in a laboratory environment, while the photovoltaic module actually works outdoors. The large difference between the simulated environment and the actual working environment leads to poor accuracy of the simulation results. Summary of the invention

[0004] The invention provides a method and device for simulating the temperature of a photovoltaic module junction box, so as to improve the accuracy of the simulation result.

[0005] In a first aspect, an embodiment of the present invention provides a method for simulating the temperature of a junction box of a photovoltaic module, which is implemented in a finite element analysis software and includes:

[0006] Construct a three-dimensional structure diagram of the junction box to be simulated according to user instructions;

[0007] Receive a heat dissipation theoretical model of the junction box input by a user, wherein the heat dissipation theoretical model includes a temperature parameter and a wind speed parameter;

[0008] receiving values ​​of other parameters in the heat dissipation theoretical model except the temperature parameter and a temperature reference condition input by a user;

[0009] A temperature simulation result of the junction box to be simulated is obtained according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of the other parameters and the temperature reference condition.

[0010] In a second aspect, an embodiment of the present invention further provides a device for simulating the temperature of a junction box of a photovoltaic module, comprising:

[0011] A composition module, used to construct a three-dimensional structure diagram of the junction box to be simulated according to user instructions;

[0012] A first receiving module, configured to receive a heat dissipation theoretical model of the junction box input by a user, wherein the heat dissipation theoretical model includes a temperature parameter and a wind speed parameter;

[0013] A second receiving module, used for receiving values ​​of other parameters in the heat dissipation theoretical model except the temperature parameter, and a temperature reference condition input by a user;

[0014] The result obtaining module is used to obtain the temperature simulation result of the junction box to be simulated according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of other parameters and the temperature reference condition.

[0015] The technical solution provided by the embodiment of the present invention constructs a three-dimensional structure diagram of the junction box to be simulated according to user instructions, receives a heat dissipation theoretical model of the junction box input by the user, the heat dissipation theoretical model includes temperature parameters and wind speed parameters, receives values ​​of other parameters except the temperature parameters in the heat dissipation theoretical model input by the user, and a temperature reference condition, obtains a temperature simulation result of the junction box to be simulated according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of other parameters and the temperature reference condition, so that the simulation result is obtained based on the wind speed, which is close to the actual outdoor working environment of the junction box, and the obtained simulation result is closer to the actual result and has higher accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0017] Figure 1 It is a schematic flow chart of a method for simulating the temperature of a junction box of a photovoltaic module provided by an embodiment of the present invention;

[0018] Figure 2 is a simulation result of a diode temperature when a diode is started provided by an embodiment of the present invention;

[0019] Figure 3 is a simulation result of the diode temperature when the diode is not started provided by an embodiment of the present invention;

[0020] Figure 4 The present invention is a schematic diagram of the structure of a device for simulating the temperature of a junction box of a photovoltaic module provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation method, structure, characteristics and effects of a method and device for simulating the temperature of a photovoltaic module junction box proposed by the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0022] An embodiment of the present invention provides a method for simulating the temperature of a photovoltaic module junction box, which is implemented in finite element analysis software and includes:

[0023] Construct a three-dimensional structure diagram of the junction box to be simulated according to user instructions;

[0024] Receive a heat dissipation theoretical model of the junction box input by a user, wherein the heat dissipation theoretical model includes a temperature parameter and a wind speed parameter;

[0025] receiving values ​​of other parameters in the heat dissipation theoretical model except the temperature parameter and a temperature reference condition input by a user;

[0026] A temperature simulation result of the junction box to be simulated is obtained according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of the other parameters and the temperature reference condition.

[0027] The technical solution provided by the embodiment of the present invention constructs a three-dimensional structure diagram of the junction box to be simulated according to user instructions, receives a heat dissipation theoretical model of the junction box input by the user, the heat dissipation theoretical model includes temperature parameters and wind speed parameters, receives values ​​of other parameters except the temperature parameters in the heat dissipation theoretical model input by the user, and a temperature reference condition, obtains a temperature simulation result of the junction box to be simulated according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of other parameters and the temperature reference condition, so that the simulation result is obtained based on the wind speed, which is close to the actual outdoor working environment of the junction box, and the obtained simulation result is closer to the actual result and has higher accuracy.

[0028] The above is the core idea of ​​the present application. The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented using other embodiments different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention in detail, for the sake of convenience, the schematic diagrams showing the device structure are not partially enlarged according to the general proportion, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and height should be included.

[0031] Figure 1FIG. 1 is a flow chart of a method for simulating the temperature of a photovoltaic module junction box provided by an embodiment of the present invention. The method is implemented in finite element analysis software, such as Figure 1 As shown, the simulation method may specifically include the following:

[0032] Step 11: Construct a three-dimensional structure diagram of the junction box to be simulated according to user instructions.

[0033] It should be noted that there are many types of finite element analysis software, and the simulation method of the photovoltaic module junction box temperature provided in this embodiment is applicable to various finite element analysis software.

[0034] Exemplarily, the user instruction may be a user controlling an operation through a mouse. Specifically, the user may directly draw a three-dimensional structure diagram of the junction box to be simulated by operating the mouse in the finite element analysis software according to a preset drawing size.

[0035] Step 12: receiving a heat dissipation theoretical model of the junction box input by a user, where the heat dissipation theoretical model includes temperature parameters and wind speed parameters.

[0036] It should be noted that the wind speed parameter is a parameter related to the wind speed, for example, the wind speed parameter may be a heat convection coefficient. Similarly, the temperature parameter is a parameter related to the temperature, for example, the temperature parameter may be a physical field of the junction box temperature.

[0037] It should also be noted that this embodiment does not limit the specific form of the heat dissipation theoretical model. Any heat dissipation theoretical model that can realize junction box temperature simulation, conforms to objective laws, has no theoretical errors, and has temperature parameters and wind speed parameters is within the protection scope of this embodiment.

[0038] Step 13: receiving values ​​of other parameters except the temperature parameter in the heat dissipation theoretical model and the temperature reference condition input by the user.

[0039] Among them, the temperature reference condition is the reference condition for determining the temperature parameter. Different temperature reference conditions correspond to different values ​​of the determined temperature parameters. Designers can reasonably set the temperature reference condition according to specific needs.

[0040] Furthermore, after the temperature reference condition is determined, the value of the corresponding temperature parameter can be calculated based on the heat dissipation theoretical model and the values ​​of other parameters in the model except the temperature parameter.

[0041] Exemplarily, the temperature reference condition may be: the temperature of the bottom of the junction box to be simulated is equal to the operating temperature of the photovoltaic assembly to which it belongs.

[0042] Step 14: Obtain the temperature simulation result of the junction box to be simulated according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of other parameters and the temperature reference conditions.

[0043] It should be noted that after the value of the temperature parameter is determined based on the heat dissipation theoretical model, the values ​​of other parameters and the temperature reference condition, the value of the temperature parameter is applied to the three-dimensional structure diagram to obtain the corresponding simulation result.

[0044] The technical solution provided in this embodiment constructs a three-dimensional structure diagram of the junction box to be simulated according to user instructions, receives a heat dissipation theoretical model of the junction box input by the user, the heat dissipation theoretical model includes temperature parameters and wind speed parameters, receives values ​​of other parameters except the temperature parameters in the heat dissipation theoretical model input by the user, and a temperature reference condition, obtains a temperature simulation result of the junction box to be simulated according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of other parameters and the temperature reference condition, so that the simulation result is obtained based on the wind speed, which is close to the actual outdoor working environment of the junction box, and the obtained simulation result is closer to the actual result and has higher accuracy.

[0045] Optionally, constructing the three-dimensional structure diagram of the junction box to be simulated according to the user instruction may include: constructing the three-dimensional structure diagrams of the shell, the potting glue, the diode and the copper substrate in the junction box to be simulated according to the user instruction respectively.

[0046] It should be noted that in this embodiment, the three-dimensional structure diagrams of the shell, potting glue, diode and copper substrate in the junction box to be simulated are constructed separately. Each component can be simulated separately, or the simulation results of the entire junction box can be viewed in combination.

[0047] In this embodiment, receiving the heat dissipation theoretical model of the junction box input by the user may include: receiving the heat dissipation theoretical model of the junction box input by the user: Where Q is the heat of the diode, k is the thermal conductivity of the material, is a vector differential operator, T is the physical field of the junction box temperature, h is the thermal convection coefficient, and h is related to v, where v is the wind speed.

[0048] Specifically, according to the heat balance equation: Q 放 =Q 吸 , the heat dissipation theoretical model of the junction box with the diode as the heat source is obtained: It can be understood that the heat dissipation theoretical model is applicable to the housing, potting compound, diode and copper substrate in the junction box.

[0049] Exemplarily, h=h1-h2, h2=0.5h1, h1=5.7+3.8v, wherein h1 is the convective heat transfer coefficient of the upper surface of the junction box to be simulated, and h2 is the convective heat transfer coefficient of the lower surface of the junction box to be simulated.

[0050] It should be noted that h2=0.5h1 and h1=5.7+3.8v are both empirical formulas for the photovoltaic modules to which the junction box belongs under outdoor working conditions, and have high accuracy and applicability. It can be understood that the heat convection coefficient h is the wind speed parameter.

[0051] It should also be noted that different wind speeds v correspond to different outdoor environments. The user can determine the thermal convection coefficient h based on the empirical value of wind speed v in various outdoor environments, and input h into the finite element analysis software, thereby simulating the junction box temperature in different outdoor environments.

[0052] Optionally, obtaining the temperature simulation results of the junction box to be simulated according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of other parameters and the temperature reference conditions may include: obtaining the temperature simulation results of the shell, the potting compound, the diode and the copper substrate in the junction box to be simulated according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of other parameters and the temperature reference conditions respectively.

[0053] It should be noted that the heat dissipation theoretical model is applicable to the shell, potting compound, diode and copper substrate in the junction box to be simulated. Based on the three-dimensional structure diagram of the above components, the temperature reference conditions, the heat dissipation theoretical model, and the values ​​of other parameters corresponding to each component in the heat dissipation theoretical model except the temperature coefficient, the temperature simulation results of each component can be obtained respectively, and then the simulation results of the junction box temperature can be obtained by combining the components.

[0054] Specifically, the heat dissipation theoretical model of the junction box: In addition to the temperature coefficient T, other parameters include the thermal conductivity k and the thermal convection coefficient h of the material.

[0055] Exemplarily, the thermal conductivities of the materials of the housing, potting compound, diode, and copper substrate may be 0.3 W / (m·K), 0.3 W / (m·K), 234 W / (m·K), and 401 W / (m·K), respectively.

[0056] Taking the shell as an example, the temperature simulation process of each component is described in detail below:

[0057] The three-dimensional structure of the shell is constructed according to the user's instructions, and the heat dissipation theoretical model of the junction box input by the user is received: Receive the values ​​of other parameters except T input by the user: k = 0.3W / (m·K); h = h1-h2 = h1-0.5h1 = 0.5h1 = 0.5*(5.7+3.8v), where v is the value of the parameter directly input by the user; Q is the heat source of the diode, and the corresponding Q is obtained according to the working state of the diode and the calculation method of the corresponding Q in each state, and the calculated Q is used as the value of the parameter directly input by the user. Then receive the temperature reference condition input by the user, for example, the temperature at the bottom of the junction box to be simulated is equal to the working temperature of the photovoltaic module to which it belongs, and then calculate the temperature parameter T, and apply the temperature parameter T to the three-dimensional structure of the shell to obtain the simulation result of the shell temperature.

[0058] It should also be noted that different materials have different thermal conductivities. The method for simulating the junction box temperature provided in this embodiment can simulate the junction box temperature of shells, potting compounds, diodes and copper substrates made of different materials, and then select a suitable junction box packaging material according to the simulation results to reduce the diode temperature.

[0059] Exemplarily, obtaining the temperature simulation results of the junction box to be simulated based on the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of other parameters and the temperature reference conditions may include: obtaining the temperature simulation results of the junction box to be simulated in two states, namely, the diode is started and the diode is not started, respectively based on the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of other parameters and the temperature reference conditions.

[0060] It should be noted that the working states of the junction box include: the diode is started and the diode is not started. In order to more comprehensively simulate the actual working conditions of the junction box, this embodiment is configured to simulate the temperature of the junction box in the above two states.

[0061] It should also be noted that the heat dissipation theoretical models of the junction box corresponding to the diode startup and the diode non-startup are: The difference is that when the diode is started, Q=U*I, where U is the voltage of the diode and I is the current flowing through the diode; when the diode is not started, the self-heating of the diode forward bias is ignored and Q=0.

[0062] It is worth noting that the length of time the junction box works outdoors will affect the voltage and current of the diode. Therefore, the Q of the diode when it starts can be obtained based on the empirical values ​​of the voltage and current of the diode corresponding to different working times, thereby realizing the temperature simulation of the junction box with a longer working time in a short time.

[0063] Similarly, when the same type of photovoltaic modules are used with different types of junction boxes, the voltage of the diode in the junction box is the same but the current is different, while when the same type of photovoltaic modules are used with the same type of junction boxes, the voltage of the diode in the junction box is different but the current is the same. The method for simulating the junction box temperature provided in this embodiment can be used to simulate the junction box temperature in the above two cases.

[0064] The following is an example of the simulation results of the diode temperature. Specifically, Figure 2 This is a simulation result of the diode temperature when the diode is started, provided by an embodiment of the present invention. Figure 3 This is a simulation result of the diode temperature when the diode is not started, provided by an embodiment of the present invention.

[0065] Figure 4 Schematic diagram of the structure of a device for simulating the temperature of a photovoltaic module junction box provided by an embodiment of the present invention. Figure 4 As shown, the simulation device for the temperature of the photovoltaic module junction box may include:

[0066] A composition module 21, used to construct a three-dimensional structure diagram of the junction box to be simulated according to user instructions;

[0067] A first receiving module 22 is used to receive a heat dissipation theoretical model of the junction box input by a user, where the heat dissipation theoretical model includes a temperature parameter and a wind speed parameter;

[0068] The second receiving module 23 is used to receive the values ​​of other parameters in the heat dissipation theoretical model except the temperature parameter, and the temperature reference condition input by the user;

[0069] The result obtaining module 24 is used to obtain the temperature simulation result of the junction box to be simulated according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of other parameters and the temperature reference conditions.

[0070] The simulation device for the temperature of the junction box of a photovoltaic module provided in this embodiment includes a composition module, a first receiving module, a second receiving module and a result acquisition module. The composition module is used to construct a three-dimensional structure diagram of the junction box to be simulated according to user instructions. The first receiving module is used to receive the heat dissipation theoretical model of the junction box input by the user, and the heat dissipation theoretical model includes temperature parameters and wind speed parameters. The second receiving module is used to receive the values ​​of other parameters except the temperature parameters in the heat dissipation theoretical model input by the user, as well as the temperature reference condition. The result acquisition module is used to obtain the temperature simulation result of the junction box to be simulated according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of other parameters and the temperature reference condition, so that the simulation result is obtained based on the wind speed, and thus is close to the actual outdoor working environment of the junction box. The obtained simulation result is closer to the actual result and has higher accuracy.

[0071] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for simulating the temperature of a photovoltaic module junction box, implemented in a finite element analysis software, characterized in that: include: Construct a three-dimensional structure diagram of the junction box to be simulated according to user instructions; Receive a heat dissipation theoretical model of the junction box input by a user, wherein the heat dissipation theoretical model includes a temperature parameter and a wind speed parameter; receiving values ​​of other parameters in the heat dissipation theoretical model except the temperature parameter and a temperature reference condition input by a user; Obtaining a temperature simulation result of the junction box to be simulated according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of the other parameters and the temperature reference condition; The heat dissipation theoretical model of the junction box receiving user input includes: Theoretical model of heat dissipation of the junction box receiving user input: , where Q is the heat of the diode, k is the thermal conductivity of the material, is a vector differential operator, T is the physical field of the junction box temperature, h is the thermal convection coefficient, and h is related to v, v is the wind speed; h=h1-h2, h2=0.5h1, h1=5.7+3.8v; wherein h1 is the convection heat transfer coefficient of the upper surface of the junction box to be simulated, and h2 is the convection heat transfer coefficient of the lower surface of the junction box to be simulated.

2. The simulation method according to claim 1, characterized in that: The three-dimensional structure diagram of the junction box to be simulated is constructed according to the user's instructions, including: According to the user's instructions, three-dimensional structural diagrams of the shell, potting glue, diode and copper substrate in the junction box to be simulated are respectively constructed.

3. The simulation method according to claim 2, characterized in that: According to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of the other parameters and the temperature reference condition, obtaining the temperature simulation result of the junction box to be simulated includes: According to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of the other parameters and the temperature reference conditions, the temperature simulation results of the shell, the potting glue, the diode and the copper substrate in the junction box to be simulated are obtained.

4. The simulation method according to claim 1, characterized in that: According to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of the other parameters and the temperature reference condition, obtaining the temperature simulation result of the junction box to be simulated includes: According to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of the other parameters and the temperature reference condition, the temperature simulation results of the junction box to be simulated in two states, namely, the diode is started and the diode is not started, are obtained.

5. The simulation method according to claim 1, characterized in that: The temperature reference condition is that the temperature at the bottom of the junction box to be simulated is equal to the operating temperature of the photovoltaic assembly to which it belongs.

6. A device for simulating the temperature of a photovoltaic module junction box, characterized in that: include: A composition module, used to construct a three-dimensional structure diagram of the junction box to be simulated according to user instructions; A first receiving module, configured to receive a heat dissipation theoretical model of the junction box input by a user, wherein the heat dissipation theoretical model includes a temperature parameter and a wind speed parameter; A second receiving module, used for receiving values ​​of other parameters in the heat dissipation theoretical model except the temperature parameter, and a temperature reference condition input by a user; A result obtaining module, used for obtaining a temperature simulation result of the junction box to be simulated according to the three-dimensional structure diagram, the heat dissipation theoretical model, the values ​​of the other parameters and the temperature reference condition; The heat dissipation theoretical model of the junction box receiving user input includes: Theoretical model of heat dissipation of the junction box receiving user input: , where Q is the heat of the diode, k is the thermal conductivity of the material, is a vector differential operator, T is the physical field of the junction box temperature, h is the thermal convection coefficient, and h is related to v, v is the wind speed; h=h1-h2, h2=0.5h1, h1=5.7+3.8v; wherein h1 is the convection heat transfer coefficient of the upper surface of the junction box to be simulated, and h2 is the convection heat transfer coefficient of the lower surface of the junction box to be simulated.

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