Test circuit, test method and test device for photovoltaic modules

Abstract

The application relates to a test circuit, a test method and a test device of a photovoltaic module. The test circuit comprises a power supply module and a measurement module; the power supply module is connected with the photovoltaic module and is used for providing a breakdown test voltage and a short-circuit test voltage to the photovoltaic module according to a test signal, the current directions of the breakdown test voltage and the short-circuit test voltage are opposite; the measurement module is connected with the photovoltaic module and is used for measuring the voltage between the photovoltaic module, obtaining a first voltage and a second voltage, the first voltage corresponds to the breakdown test voltage, and the second voltage corresponds to the short-circuit test voltage; wherein the first voltage and the second voltage are used for judging the state of the photovoltaic module. The reliability of the photovoltaic module is improved, the photovoltaic module in an abnormal state is prevented from flowing into a client end, and customer complaints caused by product abnormalities are reduced.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a test circuit, test method and test equipment for photovoltaic modules. Background Technology

[0002] In a photovoltaic module, there is a battery string formed by multiple solar cells connected in series. In order to overcome the hot spot effect of the photovoltaic module and ensure the power generation efficiency and safety of the photovoltaic module, a bypass diode connected in reverse parallel with the battery string is usually installed in the photovoltaic module.

[0003] After the photovoltaic modules are assembled, power testing and electroluminescence testing are required to detect defects in the photovoltaic modules. These testing steps may damage the bypass diodes in the photovoltaic modules, affecting the reliability of the photovoltaic modules and causing abnormal photovoltaic modules to flow to the customer. Summary of the Invention

[0004] Therefore, it is necessary to provide a test circuit, test method, and test equipment for photovoltaic modules to prevent abnormal photovoltaic modules from reaching the customer.

[0005] A test circuit for a photovoltaic module, the photovoltaic module comprising a plurality of cell strings and a plurality of bypass elements, the bypass elements and the cell strings being connected in reverse parallel; the test circuit includes:

[0006] A power supply module, connected to the photovoltaic module, is used to provide the photovoltaic module with a breakdown test voltage and an open circuit test voltage according to the test signal, wherein the current directions of the open circuit test voltage and the breakdown test voltage are opposite.

[0007] A measurement module, connected to the photovoltaic module, is used to measure the voltage across the photovoltaic module and obtain a first voltage and a second voltage. The first voltage corresponds to the breakdown test voltage, and the second voltage corresponds to the open circuit test voltage.

[0008] The first voltage and the second voltage are used to determine the state of the photovoltaic module.

[0009] In one embodiment, the test signal includes a breakdown test signal and an open circuit test signal, and the power supply module includes:

[0010] Power supply;

[0011] A switching circuit is connected to the power supply and the photovoltaic module, respectively.

[0012] The switching circuit is used to control the power supply to provide the breakdown test voltage to the photovoltaic module according to the breakdown test signal; and is also used to control the power supply to provide the open circuit test voltage to the photovoltaic module according to the open circuit test signal.

[0013] In one embodiment, the switch switching circuit includes:

[0014] A first switching unit and a second switching unit; the first end of the first switching unit is connected to the positive terminal of the power supply, and the first end of the second switching unit is connected to the negative terminal of the power supply; the second ends of the first switching unit and the second switching unit are respectively connected to the positive terminal of the photovoltaic module; the third ends of the first switching unit and the third ends of the second switching unit are respectively connected to the negative terminal of the photovoltaic module.

[0015] The breakdown test signal is used to control the first switching unit and the second switching unit to connect the positive terminal of the power supply and the positive terminal of the photovoltaic module, and the negative terminal of the power supply and the negative terminal of the photovoltaic module; the open circuit test signal is used to control the first switching unit and the second switching unit to connect the positive terminal of the power supply and the negative terminal of the photovoltaic module, and the negative terminal of the power supply and the positive terminal of the photovoltaic module.

[0016] In one embodiment, the test circuit further includes:

[0017] The control board has a first connection terminal, a second connection terminal, a third connection terminal and a fourth connection terminal. The first connection terminal is connected to the positive terminal of the power supply, the second connection terminal is connected to the negative terminal of the power supply, the third connection terminal is connected to the positive terminal of the photovoltaic module, and the fourth connection terminal is connected to the negative terminal of the photovoltaic module.

[0018] The switch switching circuit is located on the control board. The first end of the first switch unit is connected to the first connection terminal, the first end of the second switch unit is connected to the second connection terminal, the second ends of the first switch unit and the second ends of the second switch unit are respectively connected to the third connection terminal, and the third ends of the first switch unit and the third ends of the second switch unit are respectively connected to the fourth connection terminal.

[0019] In one embodiment, the first switching unit includes:

[0020] A first switch, wherein a first end of the first switch is used to receive the test signal, a second end of the first switch is connected to the positive terminal of the power supply, and a third end of the first switch is connected to the positive terminal of the photovoltaic module.

[0021] The second switch has a first terminal for receiving the test signal, a second terminal for connecting to the positive terminal of the power supply, and a third terminal for connecting to the negative terminal of the photovoltaic module.

[0022] The first switch and the second switch have different on / off states.

[0023] In one embodiment, the second switching unit includes:

[0024] The third switch has a first terminal for receiving the test signal, a second terminal for connecting to the negative terminal of the power supply, and a third terminal for connecting to the positive terminal of the photovoltaic module.

[0025] The fourth switch has a first terminal for receiving the test signal, a second terminal for connecting to the negative terminal of the power supply, and a third terminal for connecting to the negative terminal of the photovoltaic module.

[0026] The third switch and the fourth switch have different on / off states.

[0027] In one embodiment, the test circuit further includes:

[0028] A voltage filtering module, connected to the common terminal of the power supply module and the photovoltaic module, is used to filter the breakdown test voltage and the open circuit test voltage; and / or

[0029] A voltage regulator module is connected to the common terminal of the power supply module and the photovoltaic module, and is used to regulate the breakdown test voltage and the open circuit test voltage.

[0030] In one embodiment, the test circuit further includes:

[0031] The connecting plate has a first port, a second port, a third port, and a fourth port; the first port and the second port are respectively connected to the positive terminal and the negative terminal of the power supply module, the third port is connected to the positive terminal of the photovoltaic module, and the fourth port is connected to the negative terminal of the photovoltaic module.

[0032] The voltage filtering module and the voltage regulator module, which are connected in parallel, are mounted on the connection board. The first port and the third port are respectively connected to the negative terminal of the voltage regulator module, and the second port and the fourth port are respectively connected to the positive terminal of the voltage regulator module.

[0033] In one embodiment, the test circuit further includes:

[0034] The control module, connected to the power supply module, is used to send the test signal.

[0035] In one embodiment, the control module is further configured to determine the state of the photovoltaic module based on the first voltage and the second voltage.

[0036] A testing method for a photovoltaic module, the photovoltaic module comprising a plurality of cell strings and a plurality of bypass elements, wherein the bypass elements and the cell strings are connected in reverse parallel; the testing method includes:

[0037] A breakdown test voltage and an open-circuit test voltage are respectively provided to the photovoltaic module, wherein the current directions of the open-circuit test voltage and the breakdown test voltage are opposite.

[0038] The voltage across the photovoltaic module is measured to obtain a first voltage and a second voltage. The first voltage corresponds to the breakdown test voltage, and the second voltage corresponds to the open circuit test voltage.

[0039] The state of the photovoltaic module is determined based on the first voltage and the second voltage.

[0040] In one embodiment, the photovoltaic module includes a plurality of bypass elements connected in series, and the test method further includes:

[0041] Based on the first voltage and the breakdown test voltage, the number of bypass elements in the photovoltaic module that are in a breakdown state is determined.

[0042] In one embodiment, determining the state of the photovoltaic module based on the first voltage and the second voltage includes:

[0043] When the first voltage equals the first preset voltage and the second voltage equals the second preset voltage, the photovoltaic module is determined to be in a normal state.

[0044] When the first voltage is equal to the first preset voltage and the second voltage is greater than the second preset voltage, the photovoltaic module is determined to be in an open circuit state.

[0045] Wherein, the second preset voltage is less than the first preset voltage.

[0046] A testing device, the testing device comprising the testing circuit described in any of the preceding claims.

[0047] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described test method.

[0048] The aforementioned photovoltaic (PV) module test circuit provides breakdown test voltage and open-circuit test voltage with opposite current directions to both ends of the PV module, and measures the corresponding first and second voltages across the PV module. Based on the first and second voltages, it can determine whether the bypass components in the PV module are open-circuited or broken down, thereby determining the state of the PV module. This improves the reliability of the PV module, prevents abnormally condition PV modules from reaching customers, and reduces customer complaints caused by product malfunctions. The test circuit has a simple structure, quickly identifies the state of the PV module, and is less prone to misjudgment.

[0049] In the aforementioned photovoltaic (PV) module testing method, breakdown test voltage and open-circuit test voltage with opposite current directions are applied to both ends of the PV module, and the corresponding first and second voltages are measured. Based on the first and second voltages, it can be determined whether the bypass element in the PV module is open-circuited or broken down, thereby determining the state of the PV module. This improves the reliability of the PV module, prevents abnormally condition PV modules from reaching customers, and reduces customer complaints caused by product abnormalities. The testing method is simple, the state of the PV module is quickly identified, and misjudgments are less likely.

[0050] The aforementioned testing equipment provides breakdown test voltage and open-circuit test voltage with opposite current directions to both ends of the photovoltaic module, and measures the corresponding first and second voltages across the photovoltaic module. Based on the first and second voltages, it can determine whether the bypass element in the photovoltaic module is open-circuited or broken down, thereby determining the state of the photovoltaic module. This improves the reliability of the photovoltaic module, prevents abnormal photovoltaic modules from reaching customers, and reduces customer complaints caused by product abnormalities. The test circuit structure in the testing equipment is simple, the state of the photovoltaic module is quickly identified, and misjudgments are unlikely. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 This is a schematic diagram of the test circuit for a photovoltaic module in some embodiments;

[0053] Figure 2 This is a schematic diagram of the test circuit for a photovoltaic module in some other embodiments;

[0054] Figure 3 This is a schematic diagram of the test circuit for a photovoltaic module in some other embodiments;

[0055] Figure 4 This is a schematic diagram of the test circuit for a photovoltaic module in some other embodiments;

[0056] Figure 5 This is a circuit diagram of the switch switching circuit 104 in some embodiments;

[0057] Figure 6 Timing diagrams of test signals in some embodiments;

[0058] Figure 7 This is a schematic diagram of the test circuit for a photovoltaic module in some embodiments;

[0059] Figure 8 This is a circuit diagram of the test circuit for a photovoltaic module in some embodiments;

[0060] Figure 9 This is a flowchart illustrating the testing method for photovoltaic modules in some embodiments.

[0061] Explanation of reference numerals in the attached figures:

[0062] Power supply module 100; power supply 102; switch switching circuit 104; first switch unit 106; second switch unit 108; first switch 110; second switch 112; third switch 114; fourth switch 116; photovoltaic module 200; bypass element 202; battery string 204; measurement module 300; control board 400; voltage filtering module 500; voltage stabilizing module 600; connection board 700; current filtering module 800; control module 900. Detailed Implementation

[0063] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0064] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0065] It is understood that the terms "first," "second," etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first switching unit may be referred to as a second switching unit, and similarly, a second switching unit may be referred to as a first switching unit. Both the first switching unit and the second switching unit are switching units, but they are not the same switching unit.

[0066] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0067] It is understandable that "several" refers to one or more, and "multiple" refers to two or more. "At least part of an element" refers to part or all of an element.

[0068] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0069] A photovoltaic module includes several cell strings and several bypass elements, wherein the bypass elements and the cell strings are connected in anti-parallel. Each cell string includes multiple solar cell strings connected in series or parallel, used to convert light energy into electrical energy. The bypass elements are connected in anti-parallel to the cell strings to avoid the influence of hot spot effects on the cell strings. For example, the bypass elements are located in a junction box, which, when connected to the cell strings, constitutes the photovoltaic module. Further, the bypass elements include bypass diodes. As an example, the photovoltaic module includes multiple cell strings and multiple bypass elements, which are respectively and correspondingly arranged, and the multiple bypass elements are connected in series. The multiple bypass elements can be located in the same junction box or in different junction boxes; this disclosure does not limit this.

[0070] Figure 1 This is a schematic diagram of the test circuit structure for a photovoltaic module in some embodiments, such as... Figure 1As shown, this embodiment provides a test circuit for a photovoltaic module 200. The test circuit includes a power supply module 100 and a measurement module 300. The power supply module 100 is connected to the photovoltaic module 200 and is used to provide a breakdown test voltage and an open-circuit test voltage to the photovoltaic module 200 according to a test signal. The current directions of the open-circuit test voltage and the breakdown test voltage are opposite. The measurement module 300 is connected to the photovoltaic module 200 and is used to measure the voltage V across the photovoltaic module 200 and obtain a first voltage V1 and a second voltage V2. The first voltage V1 corresponds to the breakdown test voltage, and the second voltage V2 corresponds to the open-circuit test voltage. The first voltage V1 and the second voltage V2 are used to determine the state of the photovoltaic module 200.

[0071] The power supply module 100 provides the photovoltaic module 200 with breakdown test voltage and open circuit test voltage in opposite directions at different times according to the test signal. As an example, firstly, the power supply module 100 provides the photovoltaic module 200 with a breakdown test voltage flowing from the positive terminal to the negative terminal according to the test signal, with the bypass element reversed. The measurement module 300 measures the first voltage V1 across the photovoltaic module 200, which can be used to determine whether the bypass element in the photovoltaic module 200 has broken down. Secondly, the power supply module 100 provides the photovoltaic module 200 with an open circuit test voltage flowing from the negative terminal to the positive terminal according to the test signal, with the bypass element connected in the correct direction. The measurement module 300 measures the second voltage V2 across the photovoltaic module 200, which can be used to determine whether the bypass element in the photovoltaic module 200 has been open-circuited. The order in which the power supply module 100 provides the breakdown test voltage and the open circuit test voltage can be interchanged. Based on the first voltage V1 and the second voltage V2 measured by the measurement module 300, it can be determined whether the bypass element in the photovoltaic module 200 has broken down or broken down, thereby determining whether the photovoltaic module is in a normal state where the electricity can flow to the customer or in an abnormal state where the electricity cannot flow to the customer.

[0072] The aforementioned photovoltaic module test circuit provides breakdown test voltage and open-circuit test voltage with opposite current directions to both ends of the photovoltaic module 200, and measures the corresponding first voltage and second voltage across the photovoltaic module 200. Based on the first voltage and second voltage, it can determine whether the bypass element in the photovoltaic module is open-circuited or broken down, thereby determining the state of the photovoltaic module. This improves the reliability of the photovoltaic module, prevents abnormal photovoltaic modules from reaching customers, and reduces customer complaints caused by product abnormalities. The test circuit has a simple structure, quickly identifies the state of the photovoltaic module, and is less prone to misjudgment.

[0073] In some embodiments, the power supply module 100 includes a first power supply unit and a second power supply unit connected in parallel. The first power supply unit and the second power supply unit are connected in parallel and then connected in series with the photovoltaic module 200. The first power supply unit is used to provide a breakdown test voltage to the photovoltaic module 200 according to a test signal. The second power supply unit is used to provide an open circuit test voltage to the photovoltaic module 200 according to a test signal. The on / off states of the second power supply unit and the second power supply unit are opposite.

[0074] For example, the first power supply unit includes a first power source and a first power supply switch, and the second power supply unit includes a second power source and a second power supply switch; wherein the current directions of the first power source and the second power source are opposite, and the on / off states of the first power supply switch and the second power supply switch are opposite.

[0075] Figure 2 This is a schematic diagram of the test circuit structure for a photovoltaic module in some other embodiments, such as... Figure 2 As shown, in one embodiment, the test signal includes a breakdown test signal and an open circuit test signal. The power supply module 100 includes a power supply 102 and a switching circuit 104. The switching circuit 104 is connected to the power supply 102 and the photovoltaic module 200, respectively. The switching circuit 104 is used to control the power supply 102 to provide the breakdown test voltage to the photovoltaic module 200 according to the breakdown test signal in the test signal. It is also used to control the power supply 102 to provide the open circuit test voltage to the photovoltaic module 200 according to the open circuit test signal in the test signal. The switching circuit 104 is used to switch the direction of the current corresponding to the voltage provided by the power supply 102. Further, the breakdown test voltage and the open circuit test voltage have the same magnitude but opposite directions.

[0076] Figure 3 The diagram below shows the structure of a test circuit for a photovoltaic module in some embodiments. In one embodiment, the switching circuit 104 includes: a first switching unit 106 and a second switching unit 108; the first terminal A1 of the first switching unit 106 is connected to the positive terminal of the power supply 102, and the first terminal B1 of the second switching unit 108 is connected to the negative terminal of the power supply 102; the second terminal A2 of the first switching unit 106 and the second terminal B2 of the second switching unit 108 are respectively connected to the positive terminal of the photovoltaic module 200; the third terminal A3 of the first switching unit 106 and the third terminal B3 of the second switching unit 108 are respectively connected to the negative terminal of the photovoltaic module 200.

[0077] The breakdown test signal is used to control the first switching unit 106 and the second switching unit 108 to connect the positive terminal of the power supply 102 and the positive terminal of the photovoltaic module 200, and the negative terminal of the power supply 102 and the negative terminal of the photovoltaic module 200, so as to provide a breakdown test voltage to the photovoltaic module 200; the open circuit test signal is used to control the first switching unit 106 and the second switching unit 108 to connect the positive terminal of the power supply 102 and the negative terminal of the photovoltaic module 200, and the negative terminal of the power supply 102 and the positive terminal of the photovoltaic module 200, so as to provide an open circuit test voltage to the photovoltaic module 200.

[0078] Figure 4 This is a schematic diagram of the test circuit structure for a photovoltaic module in some other embodiments, such as... Figure 4 As shown, in one embodiment, the test circuit further includes a control board 400 having a first connection terminal 1, a second connection terminal 2, a third connection terminal 3, and a fourth connection terminal 4. The first connection terminal 1 is connected to the positive terminal of the power supply 102, the second connection terminal 2 is connected to the negative terminal of the power supply 102, the third connection terminal 3 is connected to the positive terminal of the photovoltaic module 200, and the fourth connection terminal 4 is connected to the negative terminal of the photovoltaic module 200.

[0079] The switch switching circuit 104 is located on the control board 400. The first end A1 of the first switch unit 106 is connected to the first connection end 1. The first end B1 of the second switch unit 108 is connected to the second connection end 2. The second end A2 of the first switch unit 106 and the second end B2 of the second switch unit 108 are respectively connected to the third connection end 3. The third end A3 of the first switch unit 106 and the third end B3 of the second switch unit 108 are respectively connected to the fourth connection end 4.

[0080] In some embodiments, the first switching unit 106 and the second switching unit 108 are further provided with control terminals, and the control terminals of the first switching unit 106 and the second switching unit 108 are used to receive test signals.

[0081] Figure 5 This is a circuit diagram of the switch switching circuit 104 in some embodiments, such as... Figure 5 As shown, in one embodiment, the first switching unit 106 includes a first switch 110 and a second switch 112.

[0082] The first terminal of the first switch 110 is used to receive the test signal, and the second terminal of the first switch 110 serves as the first terminal A1 of the first switch unit 106 and is connected to the positive terminal of the power supply 102. The third terminal of the first switch 110 serves as the second terminal A2 of the first switch unit 106 and is connected to the positive terminal of the photovoltaic module 200. The first terminal of the second switch 112 is used to receive the test signal, and the second terminal of the second switch 112 is connected to the second terminal of the first switch 110 to be connected to the positive terminal of the power supply 102. The third terminal of the second switch 112 serves as the third terminal A3 of the first switch unit 106 and is connected to the negative terminal of the photovoltaic module 200. The on / off states of the first switch 110 and the second switch 112 are different.

[0083] When the test signal controls the first switch 110 to be turned on and the second switch 112 to be turned off, the positive terminal of the power supply 102 is connected to the positive terminal of the photovoltaic module 200; when the test signal controls the second switch 112 to be turned on and the first switch 110 to be turned off, the positive terminal of the power supply 102 is connected to the negative terminal of the photovoltaic module 200. For example, the first switch 110 and / or the second switch 112 may include a single-pole single-throw switch, a device with switching function, such as a MOSFET, IGBT, or relay. Furthermore, the first switch 110 and the second switch 112 may be the same or different.

[0084] It is understood that in some embodiments, the first switching unit 106 includes a single-pole double-throw switch, the control terminal of the single-pole double-throw switch is used to receive the test signal, the first terminal of the single-pole double-throw switch is the first terminal A1 of the first switching unit 106, the second terminal of the single-pole double-throw switch is the second terminal A2 of the first switching unit 106, and the third terminal of the single-pole double-throw switch is the third terminal A3 of the first switching unit 106.

[0085] See also Figure 5 In one embodiment, the second switching unit 108 includes a third switch 114 and a fourth switch 116.

[0086] The first terminal of the third switch 114 is used to receive the test signal, and the second terminal of the third switch 114 serves as the first terminal B1 of the second switch unit 108 and is connected to the negative terminal of the power supply 102; the third terminal of the third switch 114 serves as the second terminal B2 of the second switch unit 108 and is connected to the positive terminal of the photovoltaic module 200; the first terminal of the fourth switch 116 is used to receive the test signal, and the second terminal of the fourth switch 116 is connected to the second terminal of the third switch 114 to connect to the negative terminal of the power supply 102; the third terminal of the fourth switch 116 serves as the third terminal B3 of the second switch unit 108 and is connected to the negative terminal of the photovoltaic module 200; wherein the on / off states of the third switch 114 and the fourth switch 116 are different.

[0087] When the test signal controls the third switch 114 to be turned on and the fourth switch 116 to be turned off, the negative terminal of the power supply 102 is connected to the positive terminal of the photovoltaic module 200; when the test signal controls the fourth switch 116 to be turned on and the third switch 114 to be turned off, the negative terminal of the power supply 102 is connected to the positive terminal of the photovoltaic module 200. For example, the third switch 114 and / or the fourth switch 116 may include a single-pole single-throw switch, a device with switching function, such as a MOSFET, IGBT, or relay. Furthermore, the first switch 110, the second switch 112, the third switch 114, and the fourth switch 116 may be the same or different.

[0088] It is understood that when the first switch unit 108 includes a first switch 110 and a second switch 112, and the second switch unit 110 includes a third switch 114 and a fourth switch 116, the test signal controls the first switch 110 and the fourth switch 116 to have the same on / off state, and the second switch 112 and the third switch 114 to have the same on / off state. Figure 6 Here are timing diagrams of the test signals in some embodiments, such as Figure 6 As shown, the upper figure is a timing diagram of the test signals received by the first switch 110 and the fourth switch 116, and the lower figure is a timing diagram of the test signals received by the second switch 112 and the third switch 114. T0-T2 is a test cycle of photovoltaic module 200. The test of photovoltaic module 200 starts at time T0. During the time period T0-T1, the first switch 110 and the fourth switch 116 are turned on, and the second switch 112 and the third switch 114 are turned off. During the time period T1-T2, the first switch 110 and the fourth switch 116 are turned off, and the second switch 112 and the third switch 114 are turned on. The test of photovoltaic module 200 ends at time T2.

[0089] Figure 7 This is a schematic diagram of the test circuit for a photovoltaic module in some embodiments. Figure 8 This is a circuit diagram of the test circuit for a photovoltaic module in some embodiments; such as Figure 7 , Figure 8 As shown, in one embodiment, the test circuit further includes a voltage filtering module 500. The voltage filtering module 500 is connected to the common terminal of the power supply module 100 and the photovoltaic module 200, and is used to filter the breakdown test voltage and the open-circuit test voltage. The voltage filtering module 500 suppresses fluctuations in the first and second voltages, preventing voltage spikes that could damage the bypass components in the photovoltaic module 200. As an example, the voltage filtering module 500 includes several filter capacitors, with both ends connected to the power supply module 100 and the photovoltaic module 200, respectively. The voltage across the capacitors cannot change abruptly, effectively suppressing voltage fluctuations.

[0090] See Figure 7 , Figure 8 As shown, in one embodiment, the test circuit further includes a voltage regulator module 600. The voltage regulator module 600 is connected to the common terminal of the power supply module 100 and the photovoltaic module 200, and is used to regulate the breakdown test voltage and the open-circuit test voltage. The voltage regulator module 600 suppresses fluctuations in the first and second voltages, preventing voltage spikes that could damage the bypass components in the photovoltaic module 200. As an example, the voltage regulator module 600 includes a Zener diode; the Zener diode operates in the breakdown region, and when a voltage spike occurs, the Zener diode clamps the voltage, thereby protecting the bypass components 202 in the photovoltaic module 200 from damage by the voltage spike.

[0091] like Figure 8 As shown, in one embodiment, the test circuit further includes a connection board 700; the connection board 700 has a first port 1, a second port 2, a third port 3, and a fourth port 4; the first port 1 and the second port 2 are respectively connected to the positive terminal and the negative terminal of the power supply module 100, the third port 3 is connected to the positive terminal of the photovoltaic module 200, and the fourth port 4 is connected to the negative terminal of the photovoltaic module 200. As an example, the first port 1 and the third port 3 are made of metal sheets, which can contact a probe serving as a connection end to achieve an electrical connection.

[0092] The voltage filtering module 500 and the voltage regulator module 600, connected in parallel, are mounted on the connecting plate 700. The first port 1 and the third port 3 are connected to the negative terminal of the voltage regulator module 600, and the second port 2 and the fourth port 4 are connected to the positive terminal of the voltage regulator module 600. The parallel connection of the voltage filtering module 500 and the voltage regulator module 600 can suppress voltage pulses that may occur in the test circuit, preventing additional damage to the photovoltaic module 200.

[0093] like Figure 8 As shown, in some embodiments, the test circuit of the photovoltaic module further includes: a current filtering module 800; the current filtering module 800 is connected to the power supply module 100 and the photovoltaic module 200 respectively, and is used to filter the current in the test circuit, reduce high-frequency and high-current pulses in the test loop, and further protect the bypass component 202. The voltage filtering module 500 suppresses the fluctuations of the first voltage and the second voltage, and avoids voltage spikes in the first voltage and the second voltage, which could damage the bypass component in the photovoltaic module 200. As an example, the voltage filtering module 500 includes several filter capacitors, and the two ends of the filter capacitors are connected to the power supply module 100 and the photovoltaic module 200 respectively. The voltage across the capacitor cannot change abruptly, which can effectively suppress voltage fluctuations. Exemplarily, the current filtering module 800 includes a filter inductor. Further, one end of the filter inductor is connected to the third connection terminal 3 of the control board 400, and the other end of the filter inductor is connected to the first port 1 of the connection board 700.

[0094] See Figure 8 In one embodiment, the test circuit further includes a control module 900; the control module 900 is connected to the power supply module 100 and is used to send the test signal.

[0095] As an example, the power supply module 100 generates a test signal internally.

[0096] In one embodiment, the control module 900 is connected to the measurement module 300, and the control module 900 is further configured to determine the state of the photovoltaic module 200 based on the first voltage V1 and the second voltage V2.

[0097] In one embodiment, the control module 900 determines that the photovoltaic module 200 is in a normal state when the first voltage V1 is equal to the first preset voltage and the second voltage V2 is equal to the second preset voltage; wherein the second preset voltage is less than the first preset voltage.

[0098] In one embodiment, the control module 900 determines that the photovoltaic module 200 is in an open circuit state when the first voltage V1 is equal to the first preset voltage and the second voltage V2 is greater than the second preset voltage; wherein the second preset voltage is less than the first preset voltage.

[0099] See Figure 8In one embodiment, the photovoltaic module 200 includes a plurality of bypass elements 202 and a plurality of battery strings 204 connected in series. The plurality of bypass elements 202 and the plurality of battery strings 204 are respectively arranged, and the bypass elements 202 and the corresponding plurality of battery strings 204 are connected in parallel in reverse. The control module 900 is further configured to determine the number of bypass elements 202 in the photovoltaic module 200 that are in a breakdown state based on the first voltage V1 and the second voltage V2.

[0100] For example, the measurement module 300 includes a voltmeter.

[0101] by Figure 6 and Figure 8Taking the photovoltaic module 200 as an example, the test circuit for testing the photovoltaic module 200 is described below. The power supply 102 is a current source. The positive terminal of the power supply 102 is connected to the third connection terminal 3 of the control board 400, and the negative terminal of the power supply 102 is connected to the second connection terminal 2 of the control board 400. The third connection terminal 3 of the control board 400 is connected to one end of the current filtering module 800, and the other end of the current filtering module 800 is connected to the first probe. The fourth connection terminal 4 of the control board 400 is connected to the second probe. The first port 1 and the second port 2 of the connector 700 are metal sheets. The third port 3 of the connector 700 is connected to the positive terminal of the photovoltaic module 200, and the fourth port 4 of the connector 700 is connected to the negative terminal of the photovoltaic module 200. Before time T0, the first switch 110, the second switch 112, the third switch 114, and the fourth switch 116 are disconnected. At time T0, the first probe and the second probe are pressed down. The first probe contacts the metal piece at the first port 1 of the connector 700, and the second probe contacts the metal piece at the second port 2 of the connector 700, thus starting the test of the photovoltaic module 200. The control module 900 sends a test signal or the switch switching circuit 104 generates a test signal. A breakdown test is performed during the T0-T1 time period. The test signal controls the first switch unit 108 and the second switch unit 110 located on the control board 400. The first switch 110 and the fourth switch 116... When switch 6 is turned on, switch 112 and switch 114 are turned off, so that the positive terminal of power supply 102 is connected to the positive terminal of photovoltaic module 200 and the negative terminal of power supply 102 is connected to the negative terminal of photovoltaic module 200. Power supply 102 provides breakdown test voltage. Measurement module 300 measures the first voltage V1 across photovoltaic module 200. When the first voltage V1 is equal to the first preset voltage U1, it is determined that the bypass element 202 in photovoltaic module 200 has not broken down. When the first voltage V1 is equal to three-half of the first preset voltage U1, it is determined that there is a broken bypass element 202 in photovoltaic module 200 and photovoltaic module 200 is in an abnormal state. During the T1-T2 time period, an open-circuit test is performed. At time T1, the test signal controls the first switch 110 and the fourth switch 116 to open, while the second switch 112 and the third switch 114 are turned on. This connects the positive terminal of the power supply 102 to the negative terminal of the photovoltaic module 200, and the negative terminal of the power supply 102 to the positive terminal of the photovoltaic module 200. The power supply 102 provides the open-circuit test voltage, and the measurement module 300 measures the second voltage V2 across the photovoltaic module 200. When the second voltage V2 equals the second preset voltage U2, it is determined that the bypass components 202 in the photovoltaic module 200 are interconnected and not disconnected. The second preset voltage U2 is a small voltage. If the bypass components 202 in the photovoltaic module 200 are interconnected and not broken down, the photovoltaic module 200 is determined to be in a normal state; otherwise, the photovoltaic module 200 is determined to be in an abnormal state.When the second voltage V2 is greater than the second preset voltage U2, it is determined that the bypass element 202 in the photovoltaic module 200 is disconnected, the test point voltage V2 is an extremely high voltage, the photovoltaic module 200 is in an abnormal state, at time T2, the first switch 110, the second switch 112, the third switch 114 and the fourth switch 116 are disconnected, and the test of the photovoltaic module 200 ends.

[0102] This disclosure also provides a test method for a photovoltaic module 200, the parts of which are the same as or corresponding to the test circuit of the photovoltaic module 200 described above, and will not be repeated below.

[0103] Figure 9 This is a flowchart illustrating the testing method for photovoltaic modules in some embodiments. See [link / reference] Figure 9 The test methods for photovoltaic modules 200 include:

[0104] S102 provides the photovoltaic module with the breakdown test voltage and the open circuit test voltage respectively, and the current directions of the open circuit test voltage and the breakdown test voltage are opposite.

[0105] S104, measure the voltage across the photovoltaic module and obtain a first voltage and a second voltage. The first voltage corresponds to the breakdown test voltage, and the second voltage corresponds to the open circuit test voltage.

[0106] S106, determine the state of the photovoltaic module based on the first voltage and the second voltage.

[0107] In the aforementioned photovoltaic module testing method, breakdown test voltage and open-circuit test voltage with opposite current directions are applied to both ends of the photovoltaic module 200, and the corresponding first voltage and second voltage are measured. Based on the first voltage and second voltage, it can be determined whether the bypass element in the photovoltaic module is open-circuited or broken down, thereby determining the state of the photovoltaic module. This improves the reliability of the photovoltaic module, prevents abnormal photovoltaic modules from entering the customer's market, and reduces customer complaints caused by product abnormalities. The testing method is simple, the state of the photovoltaic module is quickly identified, and misjudgment is unlikely.

[0108] In one embodiment, the photovoltaic module includes a plurality of bypass elements connected in series, and the test method further includes: determining the number of bypass elements in the photovoltaic module that are in a breakdown state based on the first voltage and the breakdown test voltage.

[0109] In one embodiment, determining the state of the photovoltaic module based on the first voltage and the second voltage includes: determining that the photovoltaic module is in a normal state when the first voltage is equal to a first preset voltage and the second voltage is equal to a second preset voltage; wherein the second preset voltage is less than the first preset voltage.

[0110] In one embodiment, determining the state of the photovoltaic module based on a first voltage and a second voltage includes: determining that the photovoltaic module is in an open-circuit state when the first voltage is equal to a first preset voltage and the second voltage is greater than the second preset voltage; wherein the second preset voltage is less than the first preset voltage.

[0111] This disclosure also provides a testing device, which includes the testing circuit described in any of the above claims, for testing photovoltaic modules.

[0112] The aforementioned testing equipment provides breakdown test voltage and open-circuit test voltage with opposite current directions to both ends of the photovoltaic module 200, and measures the corresponding first voltage and second voltage across the photovoltaic module 200. Based on the first voltage and second voltage, it can be determined whether the bypass element in the photovoltaic module is open-circuited or broken down, thereby determining the state of the photovoltaic module. This improves the reliability of the photovoltaic module, prevents abnormal photovoltaic modules from reaching customers, and reduces customer complaints caused by product abnormalities. The test circuit structure in the testing equipment is simple, the state of the photovoltaic module is quickly identified, and misjudgment is unlikely.

[0113] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described photovoltaic module testing method.

[0114] In one exemplary embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described photovoltaic module testing method.

[0115] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the above-described photovoltaic module testing method.

[0116] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0117] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0118] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0119] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A test circuit for a photovoltaic module, the photovoltaic module comprising a plurality of cell strings and a plurality of bypass elements, wherein the bypass elements and the cell strings are connected in reverse parallel; characterized in that, The test circuit includes: A power supply module, connected to the photovoltaic module, is used to provide the photovoltaic module with a breakdown test voltage and an open circuit test voltage according to the test signal, wherein the current directions of the open circuit test voltage and the breakdown test voltage are opposite. A measurement module, connected to the photovoltaic module, is used to measure the voltage across the photovoltaic module and obtain a first voltage and a second voltage. The first voltage corresponds to the breakdown test voltage, and the second voltage corresponds to the open circuit test voltage. The first voltage and the second voltage are used to determine the state of the photovoltaic module.

2. The test circuit according to claim 1, characterized in that, The test signals include breakdown test signals and open circuit test signals, and the power supply module includes: Power supply; A switching circuit is connected to the power supply and the photovoltaic module, respectively. The switching circuit is used to control the power supply to provide the breakdown test voltage to the photovoltaic module according to the breakdown test signal; and is also used to control the power supply to provide the open circuit test voltage to the photovoltaic module according to the open circuit test signal.

3. The test circuit according to claim 2, characterized in that, The switching circuit includes: A first switching unit and a second switching unit; the first end of the first switching unit is connected to the positive terminal of the power supply, and the first end of the second switching unit is connected to the negative terminal of the power supply; the second ends of the first switching unit and the second switching unit are respectively connected to the positive terminal of the photovoltaic module; the third ends of the first switching unit and the third ends of the second switching unit are respectively connected to the negative terminal of the photovoltaic module. The breakdown test signal is used to control the first switching unit and the second switching unit to connect the positive terminal of the power supply and the positive terminal of the photovoltaic module, and the negative terminal of the power supply and the negative terminal of the photovoltaic module; the open circuit test signal is used to control the first switching unit and the second switching unit to connect the positive terminal of the power supply and the negative terminal of the photovoltaic module, and the negative terminal of the power supply and the positive terminal of the photovoltaic module.

4. The test circuit according to claim 3, characterized in that, The test circuit also includes: The control board has a first connection terminal, a second connection terminal, a third connection terminal and a fourth connection terminal. The first connection terminal is connected to the positive terminal of the power supply, the second connection terminal is connected to the negative terminal of the power supply, the third connection terminal is connected to the positive terminal of the photovoltaic module, and the fourth connection terminal is connected to the negative terminal of the photovoltaic module. The switch switching circuit is located on the control board. The first end of the first switch unit is connected to the first connection terminal, the first end of the second switch unit is connected to the second connection terminal, the second ends of the first switch unit and the second ends of the second switch unit are respectively connected to the third connection terminal, and the third ends of the first switch unit and the third ends of the second switch unit are respectively connected to the fourth connection terminal.

5. The test circuit according to claim 3, characterized in that, The first switching unit includes: A first switch, wherein a first end of the first switch is used to receive the test signal, a second end of the first switch is connected to the positive terminal of the power supply, and a third end of the first switch is connected to the positive terminal of the photovoltaic module. The second switch has a first terminal for receiving the test signal, a second terminal for connecting to the positive terminal of the power supply, and a third terminal for connecting to the negative terminal of the photovoltaic module. The first switch and the second switch have different on / off states.

6. The test circuit according to claim 3, characterized in that, The second switching unit includes: The third switch has a first terminal for receiving the test signal, a second terminal for connecting to the negative terminal of the power supply, and a third terminal for connecting to the positive terminal of the photovoltaic module. The fourth switch has a first terminal for receiving the test signal, a second terminal for connecting to the negative terminal of the power supply, and a third terminal for connecting to the negative terminal of the photovoltaic module. The third switch and the fourth switch have different on / off states.

7. The test circuit according to claim 1, characterized in that, The test circuit also includes: A voltage filtering module, connected to the common terminal of the power supply module and the photovoltaic module, is used to filter the breakdown test voltage and the open circuit test voltage; and / or A voltage regulator module is connected to the common terminal of the power supply module and the photovoltaic module, and is used to regulate the breakdown test voltage and the open circuit test voltage.

8. The test circuit according to claim 7, characterized in that, The test circuit also includes: The connecting plate has a first port, a second port, a third port, and a fourth port; the first port and the second port are respectively connected to the positive terminal and the negative terminal of the power supply module, the third port is connected to the positive terminal of the photovoltaic module, and the fourth port is connected to the negative terminal of the photovoltaic module. The voltage filtering module and the voltage regulator module, which are connected in parallel, are mounted on the connection board. The first port and the third port are respectively connected to the negative terminal of the voltage regulator module, and the second port and the fourth port are respectively connected to the positive terminal of the voltage regulator module.

9. The test circuit according to claim 1, characterized in that, The test circuit also includes: The control module, connected to the power supply module, is used to send the test signal.

10. The test circuit according to claim 9, characterized in that, The control module is also used to determine the state of the photovoltaic module based on the first voltage and the second voltage.

11. A method for testing a photovoltaic module, the photovoltaic module comprising a plurality of cell strings and a plurality of bypass elements, wherein the bypass elements and the cell strings are connected in reverse parallel; characterized in that, The testing method includes: A breakdown test voltage and an open-circuit test voltage are respectively provided to the photovoltaic module, wherein the current directions of the open-circuit test voltage and the breakdown test voltage are opposite. The voltage across the photovoltaic module is measured to obtain a first voltage and a second voltage. The first voltage corresponds to the breakdown test voltage, and the second voltage corresponds to the open circuit test voltage. The state of the photovoltaic module is determined based on the first voltage and the second voltage.

12. The test method according to claim 11, characterized in that, The photovoltaic module includes multiple bypass elements connected in series, and the test method further includes: Based on the first voltage and the breakdown test voltage, determine the number of bypass elements in the photovoltaic module that are in a breakdown state.

13. The test method according to claim 11, characterized in that, The step of determining the state of the photovoltaic module based on the first voltage and the second voltage includes: When the first voltage equals the first preset voltage and the second voltage equals the second preset voltage, the photovoltaic module is determined to be in a normal state. When the first voltage is equal to the first preset voltage and the second voltage is greater than the second preset voltage, the photovoltaic module is determined to be in an open circuit state. Wherein, the second preset voltage is less than the first preset voltage.

14. A testing device, characterized in that, The testing equipment includes the testing circuit according to any one of claims 1-10.

15. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the test method according to any one of claims 11 to 13.

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