A method, device, equipment and storage medium for hot spot test of a photovoltaic module

Abstract

Embodiments of the present application disclose a kind of hot spot test method, device, equipment and storage medium of photovoltaic module, comprising: determining the cell piece of maximum electric leakage in photovoltaic module;Different shielding ratio is shielded to cell piece, reference inflection point is combined, the target shielding area of photovoltaic module is determined, wherein reference inflection point is determined by the maximum working current and maximum working voltage corresponding to the maximum power of photovoltaic module measured under standard test environment;Hot spot is selected on cell piece, and target shielding area is shielded non-hot spot area;Determine the hot spot temperature of photovoltaic module.This scheme determines reference inflection point by the current and voltage corresponding to the maximum power of photovoltaic module measured under standard test environment, and then realizes the determination of target shielding area in the hot spot test of photovoltaic module.Compared with the method for determining reference inflection point by maximum current in prior art, this scheme can be applied to the determination of shielding area of cell piece without obvious reference inflection point, and the accuracy of determining shielding area is improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of photovoltaic power generation, and particularly to a hot spot test method, device, equipment and storage medium for a photovoltaic module. BACKGROUND

[0002] Hot spot test is one of the basic performance test items of a photovoltaic module, and generally needs to be tested according to IEC61215 MQT09 when the battery material, structure, size and module version change. The best shading area of the battery needs to be selected before testing, and the purpose is to make the shaded battery work in the worst condition, that is, the battery has the maximum heat power and the highest temperature. The requirement of the standard IEC61215 is to evaluate whether the photovoltaic module meets the requirements of safety regulations, performance and reliability under the worst condition.

[0003] The traditional IEC standard method for selecting the shading area depends on the obvious inflection point of the I-V curve of the shaded battery, and whether the inflection point current is close to Imp is used to determine whether the shading area is optimal. However, with the development of large-size battery products such as 182mm and 210mm, the increase in area also increases the reverse leakage current (Irev) of the battery. For these products, it is difficult to observe the obvious inflection point of the current-voltage curve of the module after shading the battery, so it is impossible to accurately determine the optimal shading area. SUMMARY

[0004] Embodiments of the present application provide a hot spot test method, device, equipment and storage medium for a photovoltaic module, which can be used to determine the shading area of a battery sheet without obvious reference inflection point, and improve the accuracy of determining the shading area.

[0005] In a first aspect, embodiments of the present application provide a hot spot test method for a photovoltaic module, comprising:

[0006] determining a battery sheet with the maximum leakage current in the photovoltaic module;

[0007] shading the battery sheet at different shading ratios, and determining a target shading area of the photovoltaic module in combination with a reference inflection point, wherein the reference inflection point is determined by the maximum working current and the maximum working voltage corresponding to the maximum power of the photovoltaic module measured under a standard test environment;

[0008] selecting a hot spot on the battery sheet, and shading the non-hot spot area with the target shading area;

[0009] determining the hot spot temperature of the photovoltaic module.

[0010] In a second aspect, embodiments of the present application also provide a hot spot test device for a photovoltaic module, comprising:

[0011] The battery piece determination module is configured to determine a battery piece with the maximum leakage current in the photovoltaic module;

[0012] The target shading area determination module is configured to determine a target shading area of the photovoltaic module by shading the battery piece at different shading ratios and in combination with a reference inflection point, wherein the reference inflection point is determined by a maximum working current and a maximum working voltage corresponding to the maximum power of the photovoltaic module measured in a standard test environment.

[0013] The hot spot selection module is configured to select a hot spot on the battery piece and shade a non-hot spot area with the best shading area.

[0014] The hot spot temperature determination module is configured to determine a hot spot temperature of the photovoltaic module.

[0015] In a third aspect, an embodiment of the present application further provides a computer device, comprising a memory and one or more processors.

[0016] The memory is configured to store one or more programs.

[0017] When the one or more programs are executed by the one or more processors, the one or more processors implement the hot spot test method of the photovoltaic module as described in the first aspect.

[0018] In a fourth aspect, an embodiment of the present application further provides a storage medium containing computer executable instructions, which, when executed by a computer processor, are used to perform the hot spot test method of the photovoltaic module as described in the first aspect.

[0019] The embodiments of the present application disclose a hot spot test method, device, equipment and storage medium of a photovoltaic module, comprising: determining a battery piece with the maximum leakage current in the photovoltaic module; shading the battery piece at different shading ratios, and determining a target shading area of the photovoltaic module in combination with a reference inflection point, wherein the reference inflection point is determined by a maximum working current and a maximum working voltage corresponding to the maximum power of the photovoltaic module measured in a standard test environment; selecting a hot spot on the battery piece, and shading a non-hot spot area with the target shading area; and determining a hot spot temperature of the photovoltaic module. The embodiments provide a technical solution for determining the best shading area in the hot spot test of the photovoltaic module by determining the current and voltage corresponding to the maximum power of the photovoltaic module measured in the standard test environment to determine the reference inflection point. Compared with the method for determining the reference inflection point by the maximum current in the prior art, the present application can be applied to the determination of the shading area of the battery piece without the obvious reference inflection point, and the accuracy of determining the shading area is improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 FIG. 1 is a schematic diagram of a typical hot spot test method of a photovoltaic module in the prior art;

[0021] Figure 2 A schematic diagram of the hot spot test standard for a photovoltaic module in the prior art;

[0022] Figure 3 A schematic diagram of the current-voltage curve without an obvious reference inflection point in the hot spot test method for a photovoltaic module;

[0023] Figure 4 A schematic diagram of the flow of the hot spot test method for a photovoltaic module provided by Embodiment One of the present application;

[0024] Figure 5 An example diagram of the hot spot test method for a photovoltaic module provided by Embodiment One of the present application;

[0025] Figure 6 Another example diagram of the hot spot test method for a photovoltaic module provided by Embodiment One of the present application;

[0026] Figure 7 An example diagram of the hot spot test method for a photovoltaic module provided by Embodiment One of the present application with an obvious reference inflection point;

[0027] Figure 8 An example diagram of the hot spot test method for a photovoltaic module provided by Embodiment One of the present application without an obvious reference inflection point;

[0028] Figure 9 A structural block diagram of a hot spot test device for a photovoltaic module provided by Embodiment Two of the present application;

[0029] Figure 10 A structural block diagram of a computer device provided by Embodiment Three of the present application. DETAILED DESCRIPTION

[0030] The present application will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely intended for the purpose of interpretation of the present application and are not limiting of the present application. In addition, it should be noted that only the parts related to the present application are shown in the accompanying drawings for the purpose of description.

[0031] Hot spot testing is one of the basic performance test items for a photovoltaic module, and changes in cell material, structure, size, and module version generally need to be tested according to the International Electrotechnical Commission (IEC) 61215 MQT09. Before testing, the best shading area of the cell needs to be selected, and the purpose is to make the shaded cell work in the worst conditions, i.e., the cell has the maximum heat power and the highest temperature. The requirement of the standard IEC61215 is to evaluate whether the photovoltaic module meets the requirements of safety regulations, performance, and reliability under this worst condition.

[0032] Figure 1 A schematic diagram of the hot spot test method of a typical photovoltaic module in the prior art, where Imp represents the maximum operating current corresponding to the maximum power, and Isc represents the current of the photovoltaic module under standard test conditions. The shaded cell consumes the power of the unshaded cell in the same cell string (i.e., the cell under the same bypass diode in parallel), and when the shading area is adjusted so that the consumed power is exactly the maximum power point of the unshaded cell in the same cell string, it is recorded that the unshaded cell in the same cell string works at Imp, and the temperature of the shaded cell is the highest.

[0033] Figure 2 A schematic diagram of the hot spot test standard of a photovoltaic module in the prior art, as shown in Figure 2 The traditional cell shading area calculation method is to perform according to the IEC61215-2-2021 standard. By trying different shading areas, the power of the photovoltaic module is tested respectively to obtain the current-voltage (i.e., I-V) curve under different shading areas. When the current of the curve inflection point (i.e., the point at which the bypass diode of the shaded cell string starts to work) approaches Imp of the unshaded module, the corresponding shading area at this time is the optimal shading area.

[0034] The traditional IEC standard method of selecting shading area relies on the fact that the I-V curve of the shaded cell has a clear reference inflection point, and whether the shading area is optimal is determined by whether the reference inflection point current approaches Imp. However, with the development of large-size cell products such as 182mm and 210mm, the increase in area also increases the reverse leakage current of the cell. For these products, after shading the cell, the I-V curve of the module is difficult to observe a clear reference inflection point, so it is impossible to accurately determine the optimal shading area. Figure 3 A schematic diagram of the current-voltage curve without a clear reference inflection point in the hot spot test method of a photovoltaic module, as shown in Figure 3 Under four shading areas of 15% to 55%, the module IV curve has no clear reference inflection point, and the optimal shading area cannot be determined. To solve this problem, the embodiment of the present application provides a hot spot test method, device, equipment and storage medium for a photovoltaic module.

[0035] Embodiment one

[0036] Figure 4 A flowchart of a hot spot test method for a photovoltaic module provided by the embodiment one of the present application. The embodiment can be applicable to the hot spot test of a photovoltaic module. The method can be executed by a hot spot test device for a photovoltaic module, which can be composed of hardware and / or software, and can generally be integrated in a computer equipment. The specific steps include the following:

[0037] S110, determine the cell sheet with the largest leakage in the photovoltaic module.

[0038] Specifically, each cell in the photovoltaic module is sequentially shielded, and the cell with the highest temperature after being shielded, that is, the cell with the largest reverse current, is taken as the cell to be shielded in the subsequent hot spot test step of the photovoltaic module.

[0039] S120, shielding the cell at different shielding ratios, and determining the target shielding area of the photovoltaic module in combination with the reference inflection point.

[0040] Among them, the cell with the largest reverse current is shielded at different ratios, and the shielding ratio can be increased by a set step, for example, the set step is 10%, and the shielding area is increased by 5%, 15%, 25%, 35%, 45%, and 55%. The current-voltage curve of the photovoltaic module is measured by shielding the cell at the corresponding shielding area.

[0041] Among them, the reference inflection point is determined by the maximum working current and the maximum working voltage corresponding to the maximum power of the photovoltaic module measured under standard test environment. In this embodiment, the standard test environment refers to the test under the condition that the cell is not shielded. For example, the standard test environment can be that the solar irradiance is 1000W / m 2 , the cell temperature is 25℃, and the atmospheric mass is AM1.5. Under the standard test environment, the current and voltage corresponding to the photovoltaic module are tested, and the current-voltage curve is drawn. The power of the photovoltaic module corresponding to each point of the current-voltage curve is calculated, and the point corresponding to the maximum power can be determined. The current corresponding to the point can be obtained, which is recorded as the maximum working current Imp, and the voltage corresponding to the point can be obtained, which is recorded as the maximum working voltage Vmp. The reference inflection point can be determined according to the maximum working current Imp and the maximum working voltage Vmp.

[0042] Among them, the target shielding area is the best shielding area of the cell to be selected for the hot spot test of the photovoltaic module, and the purpose is to make the shielded cell work in the worst condition, that is, the cell has the maximum heat power and the highest temperature.

[0043] In the prior art, the target shielding area is determined by the I-V curve inflection point and the maximum working current Imp reference line of the photovoltaic module, but it has the following disadvantages: narrow application range, only suitable for cells with obvious reference inflection point in the I-V curve, not suitable for cells without obvious reference inflection point in the I-V curve; most cells have inflection points, but the step is a curve rather than a point, and the accuracy of determining the target shielding area is poor; in addition, for cells without obvious inflection point, it generally means that the reverse current is large and the hot spot risk is high. The traditional method cannot identify high-risk cells and cannot evaluate the hot spot risk of the product.

[0044] The reference inflection point can be determined according to the maximum working current Imp and the maximum working voltage Vmp, and the shielding area corresponding to the I-V curve passing through the reference inflection point is determined as the target shielding area, compared with the prior art, the determination method of the reference inflection point provided by the embodiment of the application can determine a unique point through two reference lines, and the precision is improved. The reference inflection point is determined by using the maximum working current Imp and the maximum working voltage Vmp of the unshielded battery string, and whether the target shielding area is determined by whether the I-V curve of the battery piece after being shielded is close to the reference inflection point. The method does not require that the curve itself has a clear inflection point, and the target shielding area can be located by determining whether the I-V curve is close to the reference inflection point, thereby solving the problem of poor precision of the traditional method.

[0045] S130, selecting a hot spot on the battery piece, and shielding the non-hot spot area with the target shielding area.

[0046] Specifically, the hot spot is selected on each piece of the maximum leakage battery piece, the non-hot spot area is shielded with the worst shielding area, and the thermocouple is pasted at the hot spot and the non-hot spot area of each piece of the maximum leakage battery piece, the highest temperature of the battery piece is selected, and the temperature at the hot spot is effectively monitored.

[0047] S140, determining the hot spot temperature of the photovoltaic module.

[0048] Specifically, the positive and negative terminals of the photovoltaic module are connected in short circuit and put into a steady-state simulation box for exposure to determine the hot spot temperature of the half photovoltaic module.

[0049] The embodiment of the application discloses a hot spot test method of a photovoltaic module, comprising: determining the maximum leakage battery piece in the photovoltaic module; shielding the battery piece with different shielding ratios, and determining the target shielding area of the photovoltaic module in combination with a reference inflection point, wherein the reference inflection point is determined by the maximum working current and the maximum working voltage corresponding to the maximum power of the photovoltaic module measured under a standard test environment; selecting a hot spot on the battery piece, and shielding the non-hot spot area with the target shielding area; and determining the hot spot temperature of the photovoltaic module. The technical scheme provided by the embodiment determines the reference inflection point by the current and voltage corresponding to the maximum power of the photovoltaic module measured under the standard test environment, and then determines the target shielding area in the hot spot test of the photovoltaic module. Compared with the method of determining the reference inflection point only by the maximum current in the prior art, the present scheme can be applied to the determination of the shielding area of the battery piece without obvious reference inflection point, and the precision of determining the shielding area is improved.

[0050] As an optional embodiment of the application, the determination step of the reference inflection point can be specifically described as follows on the basis of the above embodiment:

[0051] a1) measuring the working current and working voltage of the photovoltaic module under standard test environment, and drawing the corresponding current-voltage curve.

[0052] For example, the standard test environment can be that the solar irradiance intensity is 1000 W / m 2 , the cell temperature is 25℃, and the atmospheric mass is AM1.5. Under the standard test environment, the corresponding current and voltage of the photovoltaic module are tested, and the current-voltage curve is drawn. The current-voltage curve can be drawn in a coordinate system with voltage as the horizontal coordinate and current as the vertical coordinate.

[0053] b1) obtaining the maximum output power and the maximum working current and the maximum working voltage corresponding to the maximum output power.

[0054] It can be clearly seen that in the case of a pure resistance load, power = voltage * current. Therefore, the area of the rectangle composed of the horizontal and vertical coordinates of the point on the current-voltage curve can be considered to be proportional to the output power. By calculating the rectangular area, the maximum output power and the point corresponding to the maximum output power can be determined. The vertical coordinate of the point is marked as the maximum working current Imp, and the horizontal coordinate of the point is marked as the maximum working voltage Vmp.

[0055] c1) determining the reference inflection point according to the maximum working current and the maximum working voltage.

[0056] Specifically, a reference line corresponding to the current is formed according to the maximum working current, and a reference line corresponding to the voltage is formed according to the maximum working voltage multiplied by a set multiple. The intersection of the two reference lines can determine a unique point, which is the reference inflection point.

[0057] Optionally, the step of determining the reference inflection point according to the maximum working current and the maximum working voltage can be expressed as:

[0058] c11) traversing the vertical and horizontal coordinate information of each point on the current-voltage curve.

[0059] Wherein, the vertical and horizontal coordinates are current as the vertical coordinate and voltage as the horizontal coordinate. Traversing each point on the current-voltage curve can obtain the current and voltage values corresponding to each point.

[0060] c12) forming a first reference line based on all points with the vertical coordinate equal to the maximum working current according to the vertical and horizontal coordinate information.

[0061] Specifically, all points with the vertical coordinate equal to the maximum working current are connected to form the first reference line. It can be clearly seen that the first reference line is perpendicular to the vertical coordinate.

[0062] c13) forming a second reference line based on all points with the horizontal coordinate equal to the maximum working voltage multiplied by a set multiple according to the vertical and horizontal coordinate information.

[0063] The setting multiple can be (N-1) / N, where N represents the number of cell strings of the photovoltaic module.

[0064] Specifically, all the points with the same ordinate equal to the setting multiple of the maximum working voltage are connected to form the second reference line. It can be seen that the second reference line is perpendicular to the abscissa.

[0065] For example, if the photovoltaic module is composed of three cell strings, each of which is connected in parallel with a bypass diode, when the power consumed by the shaded cell is the largest, the other unshaded cells of the shaded cell string work at a current of Imp and a voltage of 1 / 3 Vmp. The principle is that the reference inflection point on the I-V curve represents that the diode connected in parallel with the shaded cell string starts to work, and the starting of the diode indicates that the voltage of the cell string is almost zero (actually equal to the voltage drop of the diode of about 0.4-0.7 V), so the current of the photovoltaic module is equal to the current of the shaded string, which is Imp, and the voltage of the photovoltaic module is equal to the voltage of the other two cell strings, which is 2 / 3 Vmp. If the photovoltaic module is composed of N cell strings, each of which is connected in parallel with a bypass diode, the other unshaded cells of the shaded cell string work at a current of Imp and a voltage of 1 / N Vmp. Therefore, the current of the photovoltaic module is equal to the current of the shaded string, which is Imp, and the voltage of the photovoltaic module is equal to the voltage of the other cell strings, which is (N-1) / N Vmp.

[0066] c14) The intersection of the first reference line and the second reference line is determined as the reference inflection point.

[0067] For example, Figure 5 An example diagram of the hot spot test method of the photovoltaic module provided by the first embodiment of the present application is shown in FIG. 1. Figure 5 As shown in FIG. 1, if the photovoltaic module is composed of three cell strings, each of which is connected in parallel with a bypass diode, the maximum working current corresponding to the maximum power of the photovoltaic module measured under the standard test environment is recorded as Imp, and the maximum working voltage is recorded as Vmp, the intersection of the first reference line with the ordinate equal to Imp and the second reference line with the abscissa equal to 2 / 3 Vmp is determined as the reference inflection point. The curve of the optimal shaded area passes through the reference inflection point, and the reference inflection point is the diode starting point under the shaded area.

[0068] As an optional embodiment of the present application, on the basis of the above-mentioned embodiment, the step of determining the target shaded area of the photovoltaic module in combination with the reference inflection point can be specifically expressed as:

[0069] a2) The cells are shaded at different shading ratios, and the current-voltage curve of the cell string group under the corresponding shaded area is tested and plotted.

[0070] The area of the shielding is increased from zero, and the largest current leakage battery is shielded in different proportions. The shielding proportion can be increased in a set step, for example, the set step is 10%, the shielding area is increased by 5%, 15%, 25%, 35%, 45%, and 55% when the shielding proportion is greater than zero and less than 100%. The current-voltage curve of the photovoltaic module is measured under the corresponding shielding area.

[0071] Optionally, the step of shielding the battery in different shielding proportions and testing the current-voltage curve of the battery string group under the corresponding shielding area can be specifically expressed as: the battery is shielded in a small to large shielding proportion according to a set area shielding step, and the current-voltage curve of the battery string group under the corresponding shielding area is tested and plotted.

[0072] It should be noted that the shielding area needs to be increased from small to large, because when the shielding area is greater than the target shielding area, the I-V curve can also pass through the reference inflection point, but at this time the shielded battery is not working at the maximum working current Imp, but less than Imp, and the rest of the current is passed through the diode. Because the diode is turned on and works before the shielded battery reaches Imp, the power consumed by the shielded battery is not the maximum at this time because part of the current passes through the diode.

[0073] b2) Find each target current-voltage curve passing through the reference inflection point and record the shielding area, and determine the shielding area corresponding to the current-voltage curve of the smallest shielding area as the target shielding area.

[0074] Specifically, find each target current-voltage curve passing through the reference inflection point, and record the shielding area corresponding to each curve. Although each recorded shielding area corresponds to a curve passing through the reference inflection point, as the shielding area increases, the diode has been started and has shunted a part of the current, at this time the power consumption of the shielded battery is not the maximum. Therefore, the shielding area corresponding to the current-voltage curve of the smallest shielding area is determined as the target shielding area.

[0075] For example, continuing to refer to Figure 5 The battery is shielded from 15% of the battery area, and the shielding area is increased continuously. The distance between the curve and the inflection point is getting closer and closer, and the curve at 55% shielding basically passes through the inflection point, so the shielding area of 55% shielding proportion is the target shielding area of the battery.

[0076] For example, Figure 6 Another example of the hot spot test method of the photovoltaic module provided by the first embodiment of the present application is shown in the following figure. Figure 6 As shown, the above-mentioned Figure 5For example, if the target shading area is 55%, and the shading area increases to 65%, the I-V curve can still pass the reference inflection point. However, the 65% shading curve will have a significant step, because the diode has been activated and has shunted a portion of the current, and the power consumption of the shaded battery is not maximum at this time. Therefore, the minimum shading area corresponding to the curve passing the reference inflection point needs to be determined as the target shading area.

[0077] Figure 7 An example diagram of the hot spot test method of the photovoltaic module provided in Embodiment One of the present application has a clear reference inflection point; Figure 8 An example diagram of the hot spot test method of the photovoltaic module provided in Embodiment One of the present application has no clear reference inflection point. As shown in Figure 7 and Figure 8 As shown in the figures, for the I-V curve of the battery piece, whether there is a clear reference inflection point or not, the technical solution provided in the present application is applicable.

[0078] As an optional embodiment of the present application, the technical solution is applicable to both the battery piece with a clear reference inflection point and the battery piece without a clear reference inflection point; at the same time, the first reference line and the second reference line are determined by the maximum current and the maximum voltage, so as to determine a unique reference inflection point, and it is very simple and accurate to observe whether the curve is close to a point, and the positioning accuracy is high; at the same time, it does not need to increase any hardware, only needs to increase the reference line function on the operation interface of the module power simulator, and does not increase the equipment and test cost.

[0079] Embodiment Two

[0080] Figure 9 A structural block diagram of the hot spot test device of the photovoltaic module provided in Embodiment Two of the present application is shown in Figure 9 As shown in the figure, the device comprises a battery piece determination module 21, a target shading area determination module 22, a hot spot selection module 23, and a hot spot temperature determination module 24.

[0081] The battery piece determination module 21 is configured to determine the battery piece with the maximum leakage current in the photovoltaic module.

[0082] The target shading area determination module 22 is configured to shade the battery piece at different shading ratios, and determine the target shading area of the photovoltaic module in combination with the reference inflection point, wherein the reference inflection point is determined by the maximum working current and the maximum working voltage corresponding to the maximum power of the photovoltaic module measured under the standard test environment.

[0083] The hot spot selection module 23 is configured to select a hot spot on the battery piece, and shade the non-hot spot area with the target shading area.

[0084] The hot spot temperature determination module 24 is configured to determine the hot spot temperature of the photovoltaic module.

[0085] Optionally, the target shading area determination module 22 comprises:

[0086] The first curve drawing unit is configured to measure the working current and working voltage of the photovoltaic module under the standard test environment, and draw the corresponding current-voltage curve.

[0087] The maximum output power determination unit is configured to obtain the maximum output power, and the maximum working current and maximum working voltage corresponding to the maximum output power.

[0088] The reference inflection point determination unit is configured to determine the reference inflection point according to the maximum working current and the maximum working voltage.

[0089] Optionally, the reference inflection point determination unit is specifically configured to:

[0090] traverse the longitudinal and lateral coordinate information of each point on the current-voltage curve;

[0091] form a first reference line based on all points with the same longitudinal coordinate as the maximum working current according to the longitudinal and lateral coordinate information;

[0092] form a second reference line based on all points with the same lateral coordinate as the maximum working voltage multiplied by a certain factor according to the longitudinal and lateral coordinate information;

[0093] determine the intersection of the first reference line and the second reference line as the reference inflection point.

[0094] Optionally, the target shading area determination module 22 comprises:

[0095] The second curve drawing unit is configured to test and draw the current-voltage curve of the battery string group under different shading areas by shading the battery piece at different shading ratios.

[0096] The target shading area determination unit is configured to find each target current-voltage curve passing through the reference inflection point and record the shading area, and determine the shading area corresponding to the current-voltage curve with the smallest shading area as the target shading area.

[0097] Optionally, the second curve drawing unit is specifically configured to:

[0098] shading the battery piece in sequence according to the shading ratio from small to large according to the set area shading step, and testing and drawing the current-voltage curve of the battery string group under the corresponding shading area.

[0099] The above device can perform the hot spot test method of the photovoltaic module provided by all the preceding embodiments of the present application, and has the corresponding functional modules and beneficial effects of performing the above method. Technical details not described in detail in the present embodiment can be referred to the method provided by all the preceding embodiments of the present application.

[0100] Embodiment three

[0101] Figure 10 This is a structural block diagram of a computer device provided in Embodiment 3 of the present invention, as shown below. Figure 10 As shown, the computer device includes a processor 31, a memory 32, an input device 33, and an output device 34; the number of processors 31 in the computer device can be one or more. Figure 10 Taking a processor 31 as an example; the processor 31, memory 32, input device 33, and output device 34 in a computer device can be connected via a bus or other means. Figure 10 Taking the example of a connection between China and Israel via a bus.

[0102] The memory 32, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the modules corresponding to the hot spot testing method for photovoltaic modules in this embodiment of the invention (e.g., the cell determination module 21, the target shading area determination module 22, the hot spot selection module 23, and the hot spot temperature determination module 24 in the hot spot testing device for photovoltaic modules). The processor 31 executes various functional applications and data processing of the computer device by running the software programs, instructions, and modules stored in the memory 32, thereby realizing the aforementioned hot spot testing method for photovoltaic modules.

[0103] The memory 32 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a given function; the data storage area may store data created based on terminal usage. Furthermore, the memory 32 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory, or other non-volatile solid-state storage device. In some instances, the memory 32 may further include memory remotely located relative to the processor 31, which can be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0104] Input device 33 can be used to receive input digital or character information, and to generate key signal inputs related to user settings and function control of the computer device. Output device 34 may include display devices such as a display screen.

[0105] Example 4

[0106] Embodiment 4 of the present invention also provides a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to perform a hot spot testing method for a photovoltaic module, the method comprising:

[0107] Identify the solar cell with the largest leakage current in the photovoltaic module;

[0108] The battery piece is shielded with different shielding ratios, and the target shielding area of the photovoltaic module is determined in combination with the reference inflection point, wherein the reference inflection point is determined by the maximum working current and the maximum working voltage corresponding to the maximum power of the photovoltaic module measured under a standard test environment;

[0109] The hot spot is selected on the battery piece, and the non-hot spot area is shielded with the target shielding area;

[0110] The hot spot temperature of the photovoltaic module is determined.

[0111] Of course, the storage medium provided by the embodiment of the present application includes computer executable instructions, which are not limited to the method operations described above, and can also perform related operations in the hot spot test method of the photovoltaic module provided by any embodiment of the present application.

[0112] Through the above description of the embodiments, those skilled in the art can clearly understand that the present application can be realized by software and necessary general hardware, and of course can also be realized by hardware, but in many cases the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a floppy disk, a read-only memory (ROM), a random access memory (RAM), a FLASH, a hard disk or an optical disk, etc., including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the method described in each embodiment of the present application.

[0113] It is worth noting that in the above embodiment of the hot spot test device of the photovoltaic module, each unit and module included is only divided according to the functional logic, but is not limited to the above division, as long as the corresponding function can be realized; in addition, the specific name of each functional unit is only for easy distinction, and does not limit the protection scope of the present application.

[0114] Note that the above is only the preferred embodiment of the present application and the technical principle applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, readjustments and substitutions without departing from the scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A method for testing hot spots in photovoltaic modules, characterized in that, include: Identify the solar cell with the largest leakage current in the photovoltaic module; By shading the solar cells with different shading ratios and combining the reference inflection point, the target shading area of ​​the photovoltaic module is determined. The reference inflection point is determined by the maximum operating current and maximum operating voltage corresponding to the maximum power of the photovoltaic module measured under standard test conditions. Hot spots are selected on the battery cell, and non-hot spot areas are blocked using the target blocking area; Determine the hot spot temperature of the photovoltaic module; The step of shading the solar cells with different shading ratios and determining the target shading area of ​​the photovoltaic module by combining a reference inflection point includes: The battery cells were shaded by different shading ratios, and the current-voltage curves of the battery string group under the corresponding shading area were tested and plotted. Find each target current-voltage curve that passes through the reference inflection point and record the blocking area. Determine the blocking area related to the target current-voltage curve corresponding to the minimum blocking area as the target blocking area.

2. The method according to claim 1, characterized in that, The steps for determining the reference inflection point include: The operating current and operating voltage of the photovoltaic module were measured under standard testing conditions, and the corresponding current-voltage curves were plotted. Obtain the maximum output power and the corresponding maximum operating current and maximum operating voltage; The reference inflection point is determined based on the maximum operating current and the maximum operating voltage.

3. The method according to claim 2, characterized in that, Determining the reference inflection point based on the maximum operating current and the maximum operating voltage includes: Iterate through the coordinate information of each point on the current-voltage curve; Based on the aforementioned coordinate information, a first reference line is formed based on all points whose coordinates are equal to the maximum operating current; Based on the aforementioned coordinate information, a second reference line is formed by all points whose coordinates are equal to a set multiple of the maximum operating voltage. The intersection of the first reference line and the second reference line is determined as the reference inflection point.

4. The method according to claim 1, characterized in that, The process of shading the battery cells with different shading ratios and testing the current-voltage curves of the battery string under the corresponding shading area includes: According to the set area shading step, the battery cells are shaded sequentially according to the shading ratio from small to large, and the current-voltage curve of the battery string group under the corresponding shading area is tested and plotted.

5. A hot spot testing device for photovoltaic modules, characterized in that, include: The cell identification module is used to identify the cell with the largest leakage current in the photovoltaic module; The target shading area determination module is used to shade the solar cells with different shading ratios and determine the target shading area of ​​the photovoltaic module by combining a reference inflection point. The reference inflection point is determined by the maximum operating current and maximum operating voltage corresponding to the maximum power of the photovoltaic module measured under standard test conditions. A hotspot selection module is used to select hotspots on the battery cell and use the target shading area to shading non-hotspot areas. A hot spot temperature determination module is used to determine the hot spot temperature of the photovoltaic module; The target occlusion area determination module includes: The second curve plotting unit is used to block the battery cells with different blocking ratios, test and plot the current-voltage curve of the battery string under the corresponding blocking area. The target occlusion area determination unit is used to find each target current-voltage curve that passes through the reference inflection point and record the occlusion area, and determine the occlusion area related to the target current-voltage curve corresponding to the minimum occlusion area as the target occlusion area.

6. The apparatus according to claim 5, characterized in that, The target occlusion area determination module includes: The first curve plotting unit is used to measure the operating current and operating voltage of the photovoltaic module under a standard test environment and plot the corresponding current-voltage curve. The maximum output power determination unit is used to obtain the maximum output power and the maximum operating current and maximum operating voltage corresponding to the maximum output power. A reference inflection point determination unit is used to determine the reference inflection point based on the maximum operating current and the maximum operating voltage.

7. The apparatus according to claim 6, characterized in that, The reference inflection point determination unit is specifically used for: Iterate through the coordinate information of each point on the current-voltage curve; Based on the aforementioned coordinate information, a first reference line is formed based on all points whose coordinates are equal to the maximum operating current; Based on the aforementioned coordinate information, a second reference line is formed by all points whose coordinates are equal to a set multiple of the maximum operating voltage. The intersection of the first reference line and the second reference line is determined as the reference inflection point.

8. A computer device, characterized in that, include: Memory and one or more processors; The memory is used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the hot spot testing method for photovoltaic modules as described in any one of claims 1-4.

9. A storage medium containing computer-executable instructions, characterized in that, The computer-executable instructions, when executed by a computer processor, are used to perform the hot spot testing method for photovoltaic modules as described in any one of claims 1-4.

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