Testing method, testing device and testing system of photovoltaic module

Abstract

The invention discloses a test method, a test device and a test system of a photovoltaic module, and belongs to the field of photovoltaic technology. The method comprises the following steps: acquiring the maximum power of the photovoltaic module corresponding to a target test condition; under the condition that the plurality of battery pack strings of the photovoltaic module are respectively shielded, a plurality of first maximum powers corresponding to the photovoltaic module under the target test condition are acquired, and each first maximum power corresponds to the condition that one battery pack string is shielded; and based on the plurality of first maximum powers and the maximum power of the module, determining a test result of bypass diodes connected in parallel with each battery pack string in the photovoltaic module. According to the method, through the maximum power of the photovoltaic module under the target test condition and the first maximum power of the photovoltaic module when the battery pack string is shielded, whether abnormal conditions such as open circuit and short circuit occur in the bypass diode or not can be rapidly and accurately detected.

Description

Technical Field

[0001] The present application belongs to the field of photovoltaic technology, and in particular relates to a testing method, a testing device and a testing system for a photovoltaic module. Background Art

[0002] In order to prevent photovoltaic modules from being damaged by the hot spot effect, a bypass diode is usually connected in parallel between the positive and negative electrodes of the battery to prevent the energy generated by the illuminated modules from being consumed by the shaded modules, thereby reducing the loss of power generation efficiency and module safety risks.

[0003] At present, PV modules are usually tested for electroluminescence before leaving the factory to detect whether there are defects in the module cells or diodes. The cells emit light under the action of current, and the camera captures the luminous image for judgment. If black spots or dots appear in the image, it means that the cells are defective, and if black strings appear in the image, it means that the diode is short-circuited. During the test, the power is turned on many times, and the image area captured by the camera each time is limited, which makes it easy to miss the diode short circuit, and it is impossible to detect the diode disconnection such as false soldering, leaking soldering, and failure. This type of detection method cannot quickly and accurately detect the diode status. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a photovoltaic module testing method, testing device and testing system, which can quickly and accurately detect whether the bypass diode has an abnormal situation such as open circuit, short circuit, etc.

[0005] In a first aspect, the present application provides a method for testing a photovoltaic module, wherein the photovoltaic module comprises a plurality of battery strings, wherein the battery strings are connected in parallel with bypass diodes, and the method comprises:

[0006] Obtaining the maximum power of the photovoltaic module under target test conditions;

[0007] In the case where a plurality of battery strings of the photovoltaic component are respectively shielded, obtaining a plurality of first maximum powers corresponding to the photovoltaic component under the target test condition, each of the first maximum powers corresponding to a case where one battery string is shielded;

[0008] Based on the multiple first maximum powers and the assembly maximum power, a test result of the bypass diode connected in parallel to each of the battery strings in the photovoltaic assembly is determined.

[0009] According to the photovoltaic module testing method of the present application, by using the maximum module power of the photovoltaic module under the target test conditions and the first maximum power of the photovoltaic module when the battery string is shielded, it is judged whether each bypass diode in the photovoltaic module plays a cut-off role when not shielded and a conduction role when shielded, so whether the bypass diode has abnormal conditions such as open circuit or short circuit.

[0010] According to an embodiment of the present application, determining the test result of the bypass diode connected in parallel to each of the battery strings in the photovoltaic assembly based on the multiple first maximum powers and the assembly maximum power includes:

[0011] Based on the maximum power of the component and the rated power generation power corresponding to each of the battery strings, determining a component power range corresponding to a situation where each of the battery strings is blocked;

[0012] Respectively comparing the first maximum power corresponding to the situation where each battery string is blocked with the component power range to obtain a power comparison result corresponding to each battery string;

[0013] Based on the power comparison result, the test result of the bypass diode connected in parallel to each of the battery strings in the photovoltaic assembly is determined.

[0014] According to an embodiment of the present application, determining the test result of the bypass diode connected in parallel to each of the battery strings in the photovoltaic assembly based on the power comparison result includes:

[0015] When the first maximum power corresponding to the situation where the first battery string is shielded is less than the minimum value of the component power range, it is determined that the bypass diode connected in parallel to the first battery string is open-circuited.

[0016] According to an embodiment of the present application, determining the test result of the bypass diode connected in parallel to each of the battery strings in the photovoltaic assembly based on the power comparison result includes:

[0017] When the first maximum power corresponding to the situation where the second battery string is shielded is greater than the maximum value of the component power range, it is determined that the bypass diode connected in parallel to the second battery string is short-circuited.

[0018] According to one embodiment of the present application, the temperature of the target test condition is 25°C, and the radiance of the target test condition is 1000W / m 2 .

[0019] In a second aspect, the present application provides a testing device for a photovoltaic module, wherein the photovoltaic module comprises a plurality of battery strings, wherein the battery strings are connected in parallel with bypass diodes, and the device comprises:

[0020] A first acquisition module is used to acquire the maximum power of the photovoltaic module under target test conditions;

[0021] A second acquisition module is used to acquire a plurality of first maximum powers corresponding to the photovoltaic assembly under the target test condition when the plurality of battery strings of the photovoltaic assembly are respectively blocked, each of the first maximum powers corresponding to a situation where one battery string is blocked;

[0022] A processing module is used to determine the test result of the bypass diode connected in parallel to each of the battery strings in the photovoltaic component based on the multiple first maximum powers and the component maximum power.

[0023] According to the photovoltaic module testing device of the present application, by measuring the maximum module power of the photovoltaic module under the target test conditions and the first maximum power of the photovoltaic module when the battery string is shielded, it is judged whether each bypass diode in the photovoltaic module plays a cut-off role when not shielded and a conduction role when shielded, and whether the bypass diode has abnormal conditions such as open circuit or short circuit can be detected quickly and accurately.

[0024] In a third aspect, the present application provides a photovoltaic module testing system, the system comprising:

[0025] A power measuring device, the power measuring device is connected to the photovoltaic assembly to be tested, the power measuring device is used to measure the maximum power of the photovoltaic assembly under target test conditions, the photovoltaic assembly includes a plurality of battery strings, and the battery strings are connected in parallel with bypass diodes;

[0026] An environmental simulation device, the environmental simulation device is used to provide a test environment of the target test conditions for the photovoltaic module;

[0027] As in the photovoltaic module testing device described in the second aspect above, the testing device is connected to the power measuring device and the environment simulation device.

[0028] According to one embodiment of the present application, the power measurement device includes a data acquisition device and a power control device, the data acquisition device is connected to the photovoltaic component, the data acquisition device is used to collect power data, the power control device is connected to the photovoltaic component, and the power control device is used to control the photovoltaic component to output maximum power.

[0029] According to an embodiment of the present application, the power control device includes a variable resistor, the variable resistor is connected to the photovoltaic component, and the variable resistor changes within a target resistance range.

[0030] According to an embodiment of the present application, the power control device includes a first resistor and a first capacitor, the first resistor is connected to the photovoltaic component, and the first capacitor is connected in parallel to both ends of the photovoltaic component.

[0031] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0033] Figure 1 This is one of the flow charts of the photovoltaic module testing method provided in the embodiment of the present application;

[0034] Figure 2 This is the second flow chart of the photovoltaic module testing method provided in the embodiment of the present application;

[0035] Figure 3 is a schematic diagram of the structure of a photovoltaic module testing device provided in an embodiment of the present application;

[0036] Figure 4 This is one of the structural schematic diagrams of the photovoltaic module testing system provided in the embodiment of the present application;

[0037] Figure 5 This is one of the structural schematic diagrams of the photovoltaic assembly provided in the embodiment of the present application;

[0038] Figure 6 This is the second structural schematic diagram of the photovoltaic assembly provided in the embodiment of the present application;

[0039] Figure 7 This is the third structural schematic diagram of the photovoltaic assembly provided in the embodiment of the present application;

[0040] Figure 8 This is the fourth structural schematic diagram of the photovoltaic assembly provided in the embodiment of the present application;

[0041] Fig. 9 This is the second structural schematic diagram of the photovoltaic module testing system provided in the embodiment of the present application.

[0042] Reference numerals:

[0043] Testing device 300, first acquisition module 310, second acquisition module 320, processing module 330,

[0044] Current collection device 411, voltage collection device 412, power calculation device 413,

[0045] variable resistor 421, first resistor 422, first capacitor 423, first switch 424, second switch 425,

[0046] Temperature control device 510, shading plate 520,

[0047] Photovoltaic module 600 , battery string 610 , bypass diode 620 . DETAILED DESCRIPTION

[0048] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0049] Reference below Figure 1-Figure 9 A testing method of a photovoltaic assembly 600 , a testing device 300 of a photovoltaic assembly 600 , and a testing system of a photovoltaic assembly 600 according to embodiments of the present application are described.

[0050] The testing method of the photovoltaic module 600 of the embodiment of the present application can be used to detect whether the bypass diode 620 in the photovoltaic module 600 has an abnormal condition such as open circuit, short circuit, etc.

[0051] The photovoltaic assembly 600 includes a plurality of battery strings 610 , and the battery strings 610 are connected in parallel with bypass diodes 620 . The plurality of battery strings 610 can be connected in series.

[0052] In actual applications, when a battery string 610 is blocked, the bypass diode 620 connected in parallel to the battery string 610 acts as a bypass, allowing the current generated by other battery strings 610 in the photovoltaic module 600 to flow through the bypass diode 620, effectively preventing the hot spot effect from damaging the module.

[0053] like Figure 1 As shown, the testing method of the photovoltaic assembly 600 according to the embodiment of the present application includes step 110 , step 120 and step 130 .

[0054] Step 110: Obtain the maximum power of the photovoltaic module 600 under the target test conditions.

[0055] The target test condition refers to providing the photovoltaic module 600 with irradiation and temperature within a certain numerical range so that the photovoltaic module 600 can work to convert light energy into electrical energy.

[0056] In this embodiment, the maximum power of the assembly is the maximum DC power that can be generated by the photovoltaic assembly 600 without any shielding under the target test conditions.

[0057] In this step, when the photovoltaic assembly 600 outputs maximum power under target test conditions, data such as current and voltage of the photovoltaic assembly 600 may be measured, and the maximum assembly power of the photovoltaic assembly 600 may be calculated based on the measured data.

[0058] For example, Figure 5 As shown, the photovoltaic component 600 includes three battery strings 610 connected in series, and the photovoltaic component 600 is not blocked in any way. Under the target test conditions, the maximum component power P corresponding to the photovoltaic component 600 is obtained.

[0059] Step 120 : Acquire a plurality of first maximum powers corresponding to the photovoltaic assembly 600 under target test conditions while the plurality of battery strings 610 of the photovoltaic assembly 600 are respectively shielded.

[0060] Each first maximum power corresponds to a situation where a battery string 610 is blocked.

[0061] In this embodiment, multiple battery strings 610 of the photovoltaic assembly 600 are shielded respectively, and each time a battery string 610 is shielded, a first maximum power corresponding to the maximum power output of the photovoltaic assembly 600 under target test conditions is obtained.

[0062] In actual implementation, a device such as a sunshade 520 can be used to block the battery string 610 of the photovoltaic component 600. When the photovoltaic component 600 outputs maximum power under the target test conditions, the current, voltage and other data of the photovoltaic component 600 are measured, and the first maximum power of the photovoltaic component 600 is calculated based on the measured data.

[0063] For example, Figure 6 As shown, a sunshade 520 is used to shield the battery string 610 on the left side of the photovoltaic component 600, and a first maximum power P1 corresponding to the photovoltaic component 600 is obtained under target test conditions.

[0064] like Figure 7 As shown, a sunshade 520 is used to shield the battery string 610 in the middle of the photovoltaic assembly 600, and a first maximum power P2 corresponding to the photovoltaic assembly 600 is obtained under target test conditions.

[0065] like Figure 8 As shown, a sunshade 520 is used to shield the battery string 610 on the right side of the photovoltaic component 600, and under the target test conditions, the first maximum power P3 corresponding to the photovoltaic component 600 is obtained.

[0066] In this embodiment, the photovoltaic component 600 includes three battery strings 610 connected in series, which respectively shield the three battery strings 610 of the photovoltaic component 600. Each time a battery string 610 is shielded, a first maximum power is obtained, and three first maximum powers P1, P2, and P3 are obtained.

[0067] It should be noted that the first maximum power and the component maximum power are both obtained under target test conditions, which can ensure that the measured power data is related to the shading condition of the photovoltaic component 600 and avoid power data differences caused by irradiation and temperature changes.

[0068] Step 130 : Based on the multiple first maximum powers and the assembly maximum power, determine the test results of the bypass diodes 620 connected in parallel to the battery strings 610 in the photovoltaic assembly 600 .

[0069] It can be understood that when a certain battery string 610 in the photovoltaic module 600 is blocked, if the bypass diode 620 connected in parallel with the battery string 610 is normal, the bypass diode 620 will play a reverse cutoff role when not blocked, and the battery string 610 will output power normally. When blocked, the bypass diode 620 will be turned on, and the battery string 610 will be short-circuited. When the battery string 610 is blocked or not, the output power of the photovoltaic module 600 changes accordingly.

[0070] If the bypass diode 620 connected in parallel with the battery string 610 encounters abnormal conditions such as short circuit or open circuit, the reverse cutoff and conduction functions of the bypass diode 620 will fail. When the battery string 610 is shielded or not, the changes in the output power of the photovoltaic module 600 do not conform to the change pattern of the output power of the photovoltaic module 600 when the bypass diode 620 is normal.

[0071] For example, if the bypass diode 620 connected in parallel with the battery string 610 is short-circuited, the bypass diode 620 is always turned on, and the battery string 610 is always in a short-circuit state whether it is shielded or not, affecting the output power of the photovoltaic module 600.

[0072] For another example, if the bypass diode 620 connected in parallel with the battery string 610 is short-circuited, the bypass diode 620 is always disconnected and acts as a cutoff. When the battery string 610 is blocked, the battery string 610 consumes energy as a load, affecting the output power of the photovoltaic module 600.

[0073] In this embodiment, based on multiple first maximum powers corresponding to the photovoltaic component 600 when multiple battery strings 610 are respectively blocked, and the component maximum power corresponding to the photovoltaic component 600 when no battery string 610 is blocked, it is determined whether each bypass diode 620 in the photovoltaic component 600 plays a cut-off role when not blocked and a conduction role when blocked, and whether the bypass diode 620 connected in parallel with the battery string 610 has abnormal conditions such as short circuit or open circuit.

[0074] For example, Figure 5As shown, the photovoltaic component 600 includes three battery strings 610 connected in series, and the photovoltaic component 600 is not blocked in any way. Under the target test conditions, the maximum component power P corresponding to the photovoltaic component 600 is obtained.

[0075] like Figures 6 to 8 As shown, the sunshade 520 is used to shield the photovoltaic assembly 600 and the battery string 610 from left to right in sequence, and the first maximum power P1, P2, P3 corresponding to the photovoltaic assembly 600 is obtained under the target test conditions.

[0076] According to the change of the first maximum power P1, P2, P3 relative to the component maximum power P, it is determined whether the three bypass diodes 620 can be cut off when not blocked and turned on when blocked, and whether the bypass diodes 620 have abnormal conditions such as short circuit or open circuit.

[0077] It should be noted that the output power of the photovoltaic module 600 has a nonlinear relationship with the voltage and current. When the voltage of the photovoltaic module 600 increases from zero, the output power also increases. When the voltage reaches a certain value, the output power reaches a maximum. If the voltage continues to increase, the output power will gradually decrease. The embodiment of the present application uses the maximum power and the first maximum power of the component to characterize the power output characteristics of the photovoltaic module 600 in shielded and unshielded conditions, which can effectively reduce the impact of power errors and avoid false detection and missed detection of abnormal diodes.

[0078] According to the testing method of the photovoltaic module 600 provided in the embodiment of the present application, by using the maximum module power of the photovoltaic module 600 under the target test conditions and the first maximum power of the photovoltaic module 600 when the battery string 610 is shielded, it is judged whether each bypass diode 620 in the photovoltaic module 600 plays a cut-off role when not shielded and a conduction role when shielded, so whether the bypass diode 620 has an abnormal situation such as open circuit or short circuit.

[0079] In some embodiments, based on the plurality of first maximum powers and the maximum power of the assembly, determining the test result of the bypass diode 620 connected in parallel to each battery string 610 in the photovoltaic assembly 600 may include:

[0080] Based on the maximum power of the component and the rated power generation power corresponding to each battery string 610 , determine the component power range corresponding to the situation where each battery string 610 is blocked;

[0081] Compare the first maximum power corresponding to the situation where each battery string 610 is blocked with the component power range to obtain a power comparison result corresponding to each battery string 610;

[0082] Based on the power comparison result, the test result of the bypass diode 620 connected in parallel to each battery string 610 in the photovoltaic assembly 600 is determined.

[0083] The rated power generation is the power output by the battery string 610 when it operates normally under target test conditions, and the rated power generation of battery strings 610 of different specifications may be different.

[0084] In this embodiment, the component power range is a reasonable range of the power output by the photovoltaic component 600 when the bypass diode 620 is turned on when the battery string 610 is blocked. The component power range corresponding to the power output by the photovoltaic component 600 when the battery string 610 is blocked can be calculated based on the maximum power of the component and the rated power generation power of the battery string 610.

[0085] For example, the maximum power of the photovoltaic module 600 is P, and the rated power generation power of a battery string 610 is Pr. When the battery string 610 is blocked, the corresponding bypass diode 620 is turned on. The component power range corresponding to the blocked battery string 610 is (P-Pr-Δ, P-Pr+Δ), where Δ represents the allowable power fluctuation value.

[0086] In this embodiment, the first maximum power corresponding to the case where a certain battery string 610 is blocked is compared with the component power range corresponding to the case where the battery string 610 is blocked to obtain a power comparison result of the battery string 610. The power comparison result may include the first maximum power being within the component power range and the first maximum power exceeding the component power range.

[0087] In actual implementation, the power comparison results corresponding to the multiple battery strings 610 in the photovoltaic assembly 600 can be comprehensively analyzed to determine the test results of the bypass diodes 620 connected in parallel to each battery string 610 in the photovoltaic assembly 600.

[0088] In some embodiments, based on the power comparison result, determining the test result of the bypass diode 620 connected in parallel to each battery string 610 in the photovoltaic assembly 600 may include:

[0089] When the first maximum power corresponding to the case where the first battery string 610 is shielded is less than the minimum value of the component power range, it is determined that the bypass diode 620 connected in parallel to the first battery string 610 is open-circuited.

[0090] It can be understood that the component power range corresponding to the situation where the first battery string 610 is blocked can be determined according to the rated power generation power of the first battery string 610 and the maximum power of the component.

[0091] In this embodiment, the first maximum power corresponding to the case where the first battery string 610 is blocked is less than the minimum value of the component power range, indicating that when the first battery string 610 is blocked, the first battery string 610, as a load, consumes the power generated by other battery strings 610 in the photovoltaic component 600, and the bypass diode 620 connected in parallel to the first battery string 610 does not function as a conductor, that is, the bypass diode 620 connected in parallel to the first battery string 610 is open-circuited.

[0092] For example, Figure 5 As shown, the photovoltaic component 600 includes three battery strings 610 of the same specifications connected in series. The photovoltaic component 600 has no shielding. Under the target test conditions, the maximum component power P=600W corresponding to the photovoltaic component 600 is obtained, and the rated power generation power of each battery string 610 is 200W.

[0093] In this embodiment, the component power range corresponding to shielding any battery string 610 is (400W-Δ, 400W+Δ), where Δ represents the allowable power fluctuation value, Δ=0W-5W.

[0094] like Figure 6 and Figure 8 As shown, the sunshade 520 is used to respectively shield the battery strings 610 on the left and right sides of the photovoltaic module 600. Under the target test conditions, the first maximum power P1=P3=400W corresponding to the photovoltaic module 600 is obtained, which is 30%-40% lower than P and is within the module power range, indicating that the bypass diodes 620 connected in parallel to the battery strings 610 on the left and right sides are normal.

[0095] like Figure 7 As shown, a sunshade 520 is used to shield the battery string 610 in the middle of the photovoltaic component 600. Under the target test conditions, the first maximum power P2=200W corresponding to the photovoltaic component 600 is obtained, which is less than the minimum value of the component power range of 400W-Δ, and is 60%-70% lower than P. After shielding the battery string 610 in the middle, a hot spot effect occurs, and the bypass diode 620 in parallel with the battery string 610 in the middle is open-circuited and cannot start forward operation.

[0096] In some embodiments, based on the power comparison result, determining the test result of the bypass diode 620 connected in parallel to each battery string 610 in the photovoltaic assembly 600 may include:

[0097] When the first maximum power corresponding to the case where the second battery string 610 is shielded is greater than the maximum value of the component power range, it is determined that the bypass diode 620 connected in parallel to the second battery string 610 is short-circuited.

[0098] It can be understood that the component power range corresponding to the situation where the second battery string 610 is blocked can be determined according to the rated power generation power of the second battery string 610 and the maximum power of the component.

[0099] In this embodiment, the first maximum power corresponding to the case where the second battery string 610 is blocked is greater than the maximum value of the component power range, indicating that when the second battery string 610 is blocked, the reduced output power of the photovoltaic component 600 does not match the power reduced when the second battery string 610 is short-circuited, and the second battery string 610 is also short-circuited when not blocked, and the bypass diode 620 connected in parallel with the second battery string 610 is always turned on, that is, the bypass diode 620 connected in parallel with the second battery string 610 is short-circuited.

[0100] For example, Figure 5 As shown, the photovoltaic component 600 includes three battery strings 610 of the same specifications connected in series. The photovoltaic component 600 has no shielding. Under the target test conditions, the maximum component power P=405W corresponding to the photovoltaic component 600 is obtained, and the rated power generation power of each battery string 610 is 200W.

[0101] In this embodiment, the component power range corresponding to shielding any battery string 610 is (200W-Δ, 200W+Δ), where Δ represents the allowable power fluctuation value, Δ=0W-10W.

[0102] like Figure 6 and Figure 8 As shown, the shading plate 520 is used to respectively shield the battery strings 610 on the left and right sides of the photovoltaic module 600. Under the target test conditions, the first maximum power P1=P3=210W corresponding to the photovoltaic module 600 is obtained, which is 50%-55% lower than P and is within the module power range, indicating that the bypass diodes 620 connected in parallel to the battery strings 610 on the left and right sides are normal.

[0103] like Figure 7 As shown, a sunshade 520 is used to shield the battery string 610 in the middle of the photovoltaic module 600. Under the target test conditions, the first maximum power P2=405W corresponding to the photovoltaic module 600 is obtained, which is greater than the maximum value of the module power range of 200W+Δ, and decreases by 0%-5% compared with P. The power output of the photovoltaic module 600 does not change much before and after the middle battery string 610 is shielded, and the bypass diode 620 in parallel with the middle battery string 610 is short-circuited.

[0104] It can be understood that when the rated power generation power of each battery string 610 is known to be 200W and the maximum component power P=405W corresponding to the photovoltaic component 600 is obtained, it can be determined that the bypass diode 620 of the photovoltaic component 600 is short-circuited. Combined with the first maximum power corresponding to the photovoltaic component 600 under the target test conditions when the battery string 610 is blocked, it can be located which bypass diode 620 is short-circuited.

[0105] In some embodiments, the target test condition temperature is 25°C, and the target test condition irradiance is 1000 W / m 2 .

[0106] In this embodiment, the target test conditions for obtaining the maximum power and the first maximum power of the component may be a temperature of 25°C and a radiation of 1000 W / m 2 The standard test conditions (STC) can effectively ensure the reliability and comparability of test data such as the maximum power and the first maximum power of the component.

[0107] The embodiment of the present application further provides a testing device 300 for a photovoltaic assembly 600 . The photovoltaic assembly 600 includes a plurality of battery strings 610 . The battery strings 610 are connected in parallel with bypass diodes 620 .

[0108] like Figure 3 As shown, the testing device 300 of the photovoltaic assembly 600 includes:

[0109] The first acquisition module 310 is used to acquire the maximum power of the photovoltaic component 600 under the target test conditions;

[0110] The second acquisition module 320 is used to acquire a plurality of first maximum powers corresponding to the photovoltaic assembly 600 under the target test condition when the plurality of battery strings 610 of the photovoltaic assembly 600 are respectively blocked, each first maximum power corresponding to the case where one battery string 610 is blocked;

[0111] The processing module 330 is used to determine the test result of the bypass diode 620 connected in parallel to each battery string 610 in the photovoltaic assembly 600 based on the multiple first maximum powers and the assembly maximum power.

[0112] According to the testing device 300 of the photovoltaic module 600 provided in the embodiment of the present application, by using the maximum module power of the photovoltaic module 600 under the target test conditions and the first maximum power of the photovoltaic module 600 when the battery string 610 is shielded, it is judged whether each bypass diode 620 in the photovoltaic module 600 plays a cut-off role when not shielded and a conduction role when shielded, so whether the bypass diode 620 has an abnormal situation such as open circuit or short circuit can be detected quickly and accurately.

[0113] In some embodiments, the processing module 330 is used to determine the test result of the bypass diode 620 connected in parallel to each battery string 610 in the photovoltaic assembly 600 based on the multiple first maximum powers and the assembly maximum power, including:

[0114] Based on the maximum power of the component and the rated power generation power corresponding to each battery string 610 , determine the component power range corresponding to the situation where each battery string 610 is blocked;

[0115] Compare the first maximum power corresponding to the situation where each battery string 610 is blocked with the component power range to obtain a power comparison result corresponding to each battery string 610;

[0116] Based on the power comparison result, the test result of the bypass diode 620 connected in parallel to each battery string 610 in the photovoltaic assembly 600 is determined.

[0117] In some embodiments, the processing module 330 is used to determine the test result of the bypass diode 620 connected in parallel to each battery string 610 in the photovoltaic assembly 600 based on the power comparison result, including:

[0118] When the first maximum power corresponding to the case where the first battery string 610 is shielded is less than the minimum value of the component power range, it is determined that the bypass diode 620 connected in parallel to the first battery string 610 is open-circuited.

[0119] In some embodiments, the processing module 330 is used to determine the test result of the bypass diode 620 connected in parallel to each battery string 610 in the photovoltaic assembly 600 based on the power comparison result, including:

[0120] When the first maximum power corresponding to the case where the second battery string 610 is shielded is greater than the maximum value of the component power range, it is determined that the bypass diode 620 connected in parallel to the second battery string 610 is short-circuited.

[0121] In some embodiments, the target test condition temperature is 25°C, and the target test condition irradiance is 1000 W / m 2 .

[0122] The embodiment of the present application also provides a testing system for a photovoltaic assembly 600 .

[0123] The testing system of the photovoltaic assembly 600 includes: a power measuring device, an environment simulation device, and the testing device 300 of the photovoltaic assembly 600 as described above.

[0124] The photovoltaic assembly 600 includes a plurality of battery strings 610 , and the battery strings 610 are connected in parallel with bypass diodes 620 .

[0125] In this embodiment, the environmental simulation device is used to provide a test environment with target test conditions for the photovoltaic component 600, and the power measurement device is connected to the photovoltaic component 600 to be tested, and the power measurement device is used to measure the maximum power of the photovoltaic component 600 under the target test conditions.

[0126] The target test condition refers to providing the photovoltaic module 600 with irradiation and temperature within a certain numerical range so that the photovoltaic module 600 can work to convert light energy into electrical energy.

[0127] In actual implementation, the environmental simulation device may include a light source for providing irradiation, a temperature control device 510 for controlling temperature, and other equipment to provide a test environment with target test conditions for the photovoltaic assembly 600 .

[0128] In this embodiment, the test device 300 is connected to the power measurement device and the environmental simulation device. The test device 300 can send a data range of target test conditions to the environmental simulation device, and the environmental simulation device provides a test environment with target test conditions of the corresponding data range for the photovoltaic component 600.

[0129] In some embodiments, the target test condition temperature is 25°C, and the target test condition irradiance is 1000 W / m 2 .

[0130] The testing device 300 is connected to a power measuring device, which can measure the maximum power of the photovoltaic component 600 under target test conditions. The power measuring device can also measure multiple first maximum powers of the photovoltaic component 600 under target test conditions when multiple battery strings 610 respectively shield the photovoltaic component 600.

[0131] In actual implementation, after obtaining the component maximum power and multiple first maximum powers, the test results of the bypass diodes 620 connected in parallel to each battery string 610 in the photovoltaic component 600 are determined based on the multiple first maximum powers and the component maximum power.

[0132] According to the test system of the photovoltaic module 600 provided in the embodiment of the present application, by using the maximum module power of the photovoltaic module 600 under the target test conditions and the first maximum power of the photovoltaic module 600 when the battery string 610 is shielded, it is judged whether each bypass diode 620 in the photovoltaic module 600 plays a cut-off role when not shielded and a conduction role when shielded, so whether the bypass diode 620 has an abnormal situation such as open circuit or short circuit can be detected quickly and accurately.

[0133] In some embodiments, the power measurement device includes a data acquisition device and a power control device. The data acquisition device is connected to the photovoltaic component 600 and is used to collect power data. The power control device is connected to the photovoltaic component 600 and is used to control the photovoltaic component 600 to output maximum power.

[0134] Among them, the data acquisition device may include a current acquisition device 411, a voltage acquisition device 412 and a power calculation device 413. The current acquisition device 411 collects the current of the circuit in which the photovoltaic component 600 is located, and the voltage acquisition device 412 collects the voltage of the photovoltaic component 600. The current acquisition device 411 and the voltage acquisition device 412 transmit the collected data to the power calculation device 413, and the power calculation device 413 calculates the maximum component power and the first maximum power of the output photovoltaic component 600.

[0135] The power control device is connected to the photovoltaic component 600. The power control device can adjust the current and voltage of the circuit in which the photovoltaic component 600 is located, and control the photovoltaic component 600 to output the maximum power, so that the data acquisition device can collect the maximum component power and the first maximum power of the photovoltaic component 600.

[0136] In some embodiments, the power control device includes a variable resistor 421 , which is connected to the photovoltaic assembly 600 , and the variable resistor 421 changes within a target resistance range.

[0137] It can be understood that the resistance of the variable resistor 421 can vary within the target resistance range. The variable resistor 421 is connected to the photovoltaic component 600. The variable resistor 421 is connected to the photovoltaic component 600 as a load to adjust the current and voltage of the circuit in which the photovoltaic component 600 is located, so that the data acquisition device can collect the maximum component power and the first maximum power of the photovoltaic component 600.

[0138] For example, Figure 4 As shown, the photovoltaic component 600 to be tested is connected to the test system, the current collection device 411 is connected to the photovoltaic component 600, the voltage collection device 412 is connected in parallel to both ends of the photovoltaic component 600, and the current collection device 411 and the voltage collection device 412 transmit data to the power calculation device 413.

[0139] A test environment with target test conditions is provided for the photovoltaic component 600 through the light source and the temperature control device 510. The variable resistor 421 is connected to the photovoltaic component 600 as a load, and the resistance value of the variable resistor 421 is controlled to change between 0 and ∞. The current and voltage of the circuit in which the photovoltaic component 600 is located are adjusted. The data acquisition device collects the maximum power of the photovoltaic component 600. In combination with the use of the baffle, the data acquisition device can collect the first maximum power of the photovoltaic component 600.

[0140] In some embodiments, the power control device includes a first resistor 422 and a first capacitor 423 , the first resistor 422 is connected to the photovoltaic component 600 , and the first capacitor 423 is connected in parallel to both ends of the photovoltaic component 600 .

[0141] In this embodiment, the first resistor 422 can be used to completely consume the power in the first capacitor 423, and then the electric energy generated by the photovoltaic component 600 can be used to charge the first capacitor 423. During the charging process, the loop current and voltage data are recorded, and the maximum component power and the first maximum power of the output photovoltaic component 600 are calculated.

[0142] For example, Fig. 9 As shown, the variable resistor 421 is replaced with a combination of a first resistor 422 and a first capacitor 423. Before testing, the first switch 424 is opened to completely consume the power in the first capacitor 423 using the first resistor 422. Then, the first switch 424 is disconnected and the second switch 425 is closed. The electric energy generated by the photovoltaic module 600 is used to charge the first capacitor 423. During the charging process, the loop current and voltage data are recorded to calculate the maximum power.

[0143] A specific embodiment is described below.

[0144] Connect the photovoltaic module 600 to the Figure 4 The test system shown.

[0145] like Figure 2 As shown, the irradiance of the light source and the temperature of the environmental chamber are controlled according to the requirements, providing a temperature of 25°C and a radiance of 1000W / m 2 The test environment for the target test conditions.

[0146] The resistance value of the variable resistor 421 is controlled to change between 0 and ∞, and the current and voltage of the circuit in which the photovoltaic module 600 is located are adjusted. At the same time, the voltage and current values ​​are recorded and outputted as follows: Figure 5 The maximum power P of the photovoltaic assembly 600 when there is no shielding is shown.

[0147] like Figure 6 , Figure 7 and Figure 8 As shown, the battery strings 610 located on the left, the middle, and the right are respectively shielded by the shading plate 520 to test the first maximum powers P1, P2, and P3.

[0148] The photovoltaic assembly 600 includes three battery strings 610 of the same specification connected in series, and the rated power generation power of each battery string 610 is 200W.

[0149] When the maximum power of the component P=600W, P1=P2=P3=400W, the three bypass diodes 620 are all normal. After the battery string 610 is blocked, a hot spot occurs, and the bypass diode 620 starts to work in the forward direction. Part of the current of the blocked battery string 610 passes forward through the bypass diode 620. The loop current remains basically unchanged, but the corresponding battery string 610 voltage will be clamped by the bypass diode 620 to the diode forward voltage drop.

[0150] When P=600W, P1=P3=400W, which is 30%-40% lower than P, it indicates that the bypass diodes 620 connected in parallel to the left and right battery strings 610 are normal. P2=200W, which is 60%-70% lower than P, and a hot spot effect occurs after the battery string 610 in the middle is shielded. The bypass diodes 620 connected in parallel to the battery string 610 in the middle are open-circuited and cannot start forward operation.

[0151] When P=405W, P1=P3=210W, which is 50%-55% lower than P, it indicates that the bypass diodes 620 connected in parallel to the left and right battery strings 610 are normal; P2=405W, which is 0%-5% lower than P, it is judged that the bypass diode 620 connected in parallel to the middle battery string 610 is short-circuited.

[0152] In this embodiment, by using the maximum power of the component and the first maximum power when the battery string 610 is shielded, it is determined whether each bypass diode 620 in the photovoltaic component 600 plays a cut-off role when not shielded and a conducting role when shielded, so that whether the bypass diode 620 has an open circuit, a short circuit or other abnormal conditions can be quickly and accurately detected.

[0153] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0154] In the description of the present application, it should be understood that the terms "left" and "right" indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0155] In the description of this application, "first feature" or "second feature" may include one or more of the features.

[0156] In the description of the present application, “plurality” means two or more.

[0157] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0158] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A method for testing a photovoltaic module, characterized in that: The photovoltaic assembly includes a plurality of battery strings, the battery strings are connected in parallel with bypass diodes, and the method includes: Obtaining the maximum power of the photovoltaic module under target test conditions; In the case where a plurality of battery strings of the photovoltaic component are respectively shielded, obtaining a plurality of first maximum powers corresponding to the photovoltaic component under the target test condition, each of the first maximum powers corresponding to a case where one battery string is shielded; Based on the multiple first maximum powers and the assembly maximum power, a test result of the bypass diode connected in parallel to each of the battery strings in the photovoltaic assembly is determined.

2. The photovoltaic module testing method according to claim 1, characterized in that: The step of determining the test result of the bypass diode connected in parallel to each of the battery strings in the photovoltaic assembly based on the multiple first maximum powers and the assembly maximum power includes: Based on the maximum power of the component and the rated power generation power corresponding to each of the battery strings, determining a component power range corresponding to a situation where each of the battery strings is blocked; Respectively comparing the first maximum power corresponding to the situation where each battery string is blocked with the component power range to obtain a power comparison result corresponding to each battery string; Based on the power comparison result, the test result of the bypass diode connected in parallel to each of the battery strings in the photovoltaic assembly is determined.

3. The photovoltaic module testing method according to claim 2, characterized in that: The step of determining the test result of the bypass diodes connected in parallel to each of the battery strings in the photovoltaic assembly based on the power comparison result includes: When the first maximum power corresponding to the situation where the first battery string is shielded is less than the minimum value of the component power range, it is determined that the bypass diode connected in parallel to the first battery string is open-circuited.

4. The photovoltaic module testing method according to claim 2, characterized in that: The step of determining the test result of the bypass diodes connected in parallel to each of the battery strings in the photovoltaic assembly based on the power comparison result includes: When the first maximum power corresponding to the situation where the second battery string is shielded is greater than the maximum value of the component power range, it is determined that the bypass diode connected in parallel to the second battery string is short-circuited.

5. The photovoltaic module testing method according to any one of claims 1 to 4, characterized in that: The target test condition temperature is 25°C, and the target test condition irradiance is 1000W / m 2 .

6. A photovoltaic module testing device, characterized in that: The photovoltaic assembly includes a plurality of battery strings, the battery strings are connected in parallel with bypass diodes, and the device includes: A first acquisition module is used to acquire the maximum power of the photovoltaic module under target test conditions; A second acquisition module is used to acquire a plurality of first maximum powers corresponding to the photovoltaic assembly under the target test condition when the plurality of battery strings of the photovoltaic assembly are respectively blocked, each of the first maximum powers corresponding to a situation where one battery string is blocked; A processing module is used to determine the test result of the bypass diode connected in parallel to each of the battery strings in the photovoltaic component based on the multiple first maximum powers and the component maximum power.

7. A photovoltaic module testing system, characterized in that: include: A power measuring device, the power measuring device is connected to the photovoltaic assembly to be tested, the power measuring device is used to measure the maximum power of the photovoltaic assembly under target test conditions, the photovoltaic assembly includes a plurality of battery strings, and the battery strings are connected in parallel with bypass diodes; An environmental simulation device, the environmental simulation device is used to provide a test environment of the target test conditions for the photovoltaic module; The photovoltaic module testing device according to claim 6, wherein the testing device is connected to the power measuring device and the environmental simulation device.

8. The photovoltaic module testing system according to claim 7, characterized in that: The power measurement device includes a data acquisition device and a power control device. The data acquisition device is connected to the photovoltaic component and is used to collect power data. The power control device is connected to the photovoltaic component and is used to control the photovoltaic component to output a maximum power.

9. The photovoltaic module testing system according to claim 8, characterized in that: The power control device comprises a variable resistor, the variable resistor is connected to the photovoltaic component, and the variable resistor changes within a target resistance range.

10. The photovoltaic module testing system according to claim 8, characterized in that: The power control device comprises a first resistor and a first capacitor, wherein the first resistor is connected to the photovoltaic component, and the first capacitor is connected in parallel to two ends of the photovoltaic component.

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