A detection device and method for a perovskite-crystalline silicon tandem photovoltaic module

Abstract

The present application belongs to the technical field of perovskite photovoltaic module, and relates to a detection device and method for perovskite-crystalline silicon laminated photovoltaic module. The detection device comprises a junction box, an input end of four terminals and an output end of two terminals are arranged on the junction box, the input end of four terminals of the junction box is in communication with the positive and negative output ends of perovskite top cell module and crystalline silicon bottom cell module, the positive and negative output ends of two terminals are access ends when the perovskite-crystalline silicon laminated photovoltaic module is detected, a controller, a bidirectional DC-DC converter, a switch reconstruction unit and a sampling unit are arranged in the junction box, and the switch reconstruction unit comprises a first controllable switch and a second controllable switch. The present application injects detection electric energy into perovskite top cell module and crystalline silicon bottom cell module, realizes reconstruction of external access detection current or voltage to the four-terminal detection path inside the perovskite-crystalline silicon laminated photovoltaic module through the access end, and detects perovskite top cell module and crystalline silicon bottom cell module respectively.

Description

Technical Field

[0001] This invention belongs to the field of perovskite photovoltaic module technology, and specifically relates to a testing device and method for a perovskite-crystalline silicon tandem photovoltaic module. Background Technology

[0002] Perovskite-silicon tandem photovoltaic (PV) modules are generally classified into two-terminal and four-terminal structures based on their electrical connection methods. Two-terminal structures only expose two terminals (positive and negative), facilitating connection to existing inverters and string systems. However, they require good matching between the upper and lower layers of cells in terms of current, voltage, and operating point, and are prone to mismatch under conditions of varying illumination, temperature, spectral changes, or partial shading. In four-terminal structures, the perovskite top-mounted module and the crystalline silicon bottom-mounted module each have independent positive and negative terminals, making them electrically independent and allowing them to operate at their respective optimal operating points. However, this leads to an increase in the number of external wiring connections, connectors, system costs, and on-site maintenance complexity. Taking a typical four-terminal perovskite-silicon tandem PV module as an example, the perovskite top-mounted module is typically formed by multiple elongated perovskite sub-cells connected in series, resulting in a higher output voltage and lower current; the crystalline silicon bottom-mounted module is typically formed by multiple crystalline silicon cells connected in series, resulting in a lower output voltage and higher current. Therefore, the maximum power point voltages of the two types of battery modules differ significantly, and the two outputs cannot be directly connected in parallel. Otherwise, electrical mismatch, reverse current, localized heating, or damage to sub-modules may occur.

[0003] Existing technologies typically use independent power converters, independent inverters, or one / two-way DC-DC converters to voltage-match four-terminal modules and convert them to two-terminal outputs. These solutions primarily focus on unidirectional power output during generator operation, i.e., how to convert the two generator outputs of a four-terminal tandem module into a single two-terminal output interface for connection to an inverter or load. However, these solutions often do not adequately consider the specific needs of four-terminal tandem modules during production testing, installation acceptance, field maintenance, aging assessment, and fault diagnosis.

[0004] Perovskite solar cells differ from crystalline silicon solar cells in their material systems, degradation mechanisms, temperature responses, and defect characteristics. Measuring the total voltage and current of the entire tandem module solely through a two-terminal output interface makes it difficult to accurately determine whether performance degradation is caused by the perovskite top cell, the crystalline silicon bottom cell, the interconnect structure, the packaging structure, or the power conversion circuit. Retaining a four-terminal external interface for testing purposes would increase the number of external wiring and connectors, hindering system integration and large-scale applications. Conversely, relying solely on a two-terminal interface makes it difficult to perform IV curve testing, dark-state current injection, EL detection, leakage current detection, series and parallel resistance diagnosis, aging status assessment, and stratification fault location separately for perovskite top and crystalline silicon bottom cells. Converting the four-terminal tandem module to a two-terminal output only provides the total voltage and current of the module externally, making stratification diagnosis difficult. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a detection device and method for perovskite-crystalline silicon tandem photovoltaic modules. The device utilizes an external detection power supply or testing equipment connected to an access terminal. A controller controls a switch reconfiguration unit to conduct the perovskite detection path, allowing detection power to be directly injected into the perovskite top cell module. Simultaneously, it controls a bidirectional DC-DC converter to operate in reverse and injects the power into the crystalline silicon bottom cell module via a crystalline silicon branch switch. This achieves the reconfiguration of the four-port detection path from the external detection current through the access terminal to the internal four-port detection path of the perovskite-crystalline silicon tandem photovoltaic module, solving the problem that the perovskite top cell module and the crystalline silicon bottom cell module cannot be detected separately after the perovskite-crystalline silicon tandem photovoltaic module is converted to a two-terminal design.

[0006] This invention is implemented as follows: a testing device for a perovskite-crystalline silicon tandem photovoltaic module is provided, including a junction box. The junction box has four input terminals and two output terminals. The four input terminals are connected to the positive and negative output terminals of a perovskite top-cell module and a crystalline silicon bottom-cell module via leads. The positive and negative output terminals of the two terminals are the access terminals for testing the perovskite-crystalline silicon tandem photovoltaic module. A control board is provided inside the junction box. A controller, a bidirectional DC-DC converter, a switch reconfiguration unit, and a sampling unit are respectively mounted on the control board. The controller is connected to the switch reconfiguration unit, the bidirectional DC-DC converter, and the sampling unit. The structural unit includes a first controllable switch and a second controllable switch. The first controllable switch is used to control the connection or disconnection between the positive and negative output terminals of the perovskite top solar cell module and the access terminal. The second controllable switch is used to control the connection or disconnection between the positive and negative output terminals of the crystalline silicon bottom solar cell module and the bidirectional DC-DC converter. The sampling unit is used to collect the detection voltage and detection current of the perovskite top solar cell module, the detection voltage and detection current of the crystalline silicon bottom solar cell module, and the access detection voltage and access detection current of the access terminal. The bidirectional DC-DC converter supports power flow in the power generation direction from the crystalline silicon bottom solar cell module to the access terminal, and also supports power flow in the detection direction from the access terminal to the crystalline silicon bottom solar cell module.

[0007] Furthermore, the bidirectional DC-DC converter includes four field-effect transistors Q1~Q4, two capacitors C1 and C2, and an inductor L1. Field-effect transistors Q1 and Q2 are connected in series and then in parallel with capacitor C1; field-effect transistors Q3 and Q4 are connected in series and then in parallel with capacitor C2; and inductor L1 is connected in series with field-effect transistors Q1 and Q3.

[0008] Furthermore, the detection current I of the perovskite top solar cell module pero_ref The detection current I of the crystalline silicon bottom cell module si_ref Determined according to the following relationship: I pero_ref =α ·I test , I si_ref =(1- α )·I test ; In the formula, I test The access detection current input from the access terminal, α This is the current distribution coefficient, and its value can be 0 ≤ α ≤1; when α When =1, the entire detection current is allocated to the perovskite top cell module; when α When 0 < 0, the entire detection current is allocated to the crystalline silicon bottom cell module; when 0 < ..., the detection current is allocated to the crystalline silicon bottom cell module. α When the current is less than 1, the detection current is simultaneously distributed to the perovskite top cell module and the crystalline silicon bottom cell module according to a preset ratio.

[0009] Furthermore, the first controllable switch and the second controllable switch are both field-effect transistors.

[0010] This invention is implemented as follows, and also provides a testing method for perovskite-crystalline silicon tandem photovoltaic modules. When testing the perovskite-crystalline silicon tandem photovoltaic modules, the testing device for perovskite-crystalline silicon tandem photovoltaic modules as described above is used. The testing method includes the following steps: Connect the testing instrument's input current or input voltage to the junction box of the perovskite-crystalline silicon tandem photovoltaic module testing device, and perform the following tests according to the requirements of the testing items: When it is necessary to test the perovskite top solar cell module separately, the controller controls the first controllable switch to be turned on and the second controllable switch to be turned off. The detection current or detection voltage is connected to the positive and negative output terminals of the perovskite top solar cell module separately to perform the corresponding test on the perovskite top solar cell module. When it is necessary to test the crystalline silicon bottom battery module separately, the controller controls the first controllable switch to close and the second controllable switch to open, and at the same time controls the bidirectional DC-DC converter to work in reverse. The detection current is connected to the positive and negative output terminals of the crystalline silicon bottom battery module separately through the bidirectional DC-DC converter to perform the corresponding test on the crystalline silicon bottom battery module. When it is necessary to test both the perovskite top-mounted solar cell module and the crystalline silicon bottom-mounted solar cell module simultaneously, the controller controls the first and second controllable switches to turn on at the same time, and simultaneously controls the bidirectional DC-DC converter to work in reverse. The detection current or detection voltage is connected to the positive and negative output terminals of the perovskite top-mounted solar cell module and the crystalline silicon bottom-mounted solar cell module according to the set ratio, so as to perform corresponding tests on the perovskite top-mounted solar cell module and the crystalline silicon bottom-mounted solar cell module respectively.

[0011] Furthermore, the testing items include at least one of IV scanning, EL testing, series resistance diagnosis, parallel resistance diagnosis, and leakage current detection.

[0012] Compared with the prior art, the detection device and method for perovskite-crystalline silicon tandem photovoltaic modules of the present invention include a junction box with four input terminals and two output terminals respectively. The four input terminals of the junction box are connected to the positive and negative output terminals of the perovskite top cell module and the crystalline silicon bottom cell module respectively via leads. The positive and negative output terminals of the two terminals are the access terminals for detecting the perovskite-crystalline silicon tandem photovoltaic module. A control board is set inside the junction box, and a controller, a bidirectional DC-DC converter, a switch reconfiguration unit, and a sampling unit are respectively set on the control board. The switch reconfiguration unit includes a first controllable switch and a second controllable switch. The first controllable switch is used to control the connection or disconnection between the positive and negative output terminals of the perovskite top cell module and the access terminal. The second controllable switch is used to control the connection or disconnection between the positive and negative output terminals of the crystalline silicon bottom cell module and the bidirectional DC-DC converter. The bidirectional DC-DC converter supports power flow in the power generation direction from the crystalline silicon bottom cell module to the access terminal, and also supports power flow in the detection direction from the access terminal to the crystalline silicon bottom cell module. This invention utilizes an access terminal to connect to an external detection power supply or testing equipment. The controller controls the switch reconfiguration unit to conduct the perovskite detection path, allowing the detection power to be directly injected into the perovskite top cell module. Simultaneously, it controls the bidirectional DC-DC converter to operate in reverse and injects the power into the crystalline silicon bottom cell module via the crystalline silicon branch switch. This achieves the reconfiguration of the four-port detection path from the external detection current through the access terminal to the internal perovskite-crystalline silicon tandem photovoltaic module, solving the problem that the perovskite top cell module and the crystalline silicon bottom cell module cannot be detected separately after the perovskite-crystalline silicon tandem photovoltaic module is made two-terminal. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the circuit principle of the detection device for the perovskite-crystalline silicon tandem photovoltaic module of the present invention.

[0014] Figure 2 for Figure 1 The circuit diagram of the switch reconfiguration unit in the diagram.

[0015] Figure 3 for Figure 1 A schematic diagram of the circuit principle of a bidirectional DC-DC converter.

[0016] Figure 4 This is a schematic diagram of the circuit principle of the perovskite-crystalline silicon tandem photovoltaic module in the power generation mode 4T→2T of the present invention. The perovskite top cell module is directly connected to the OUT terminal via the first controllable switch, and the crystalline silicon bottom cell module is connected to the OUT terminal via the second controllable switch and the bidirectional DC-DC converter.

[0017] Figure 5 This is a schematic diagram of the circuit principle of the perovskite-crystalline silicon tandem photovoltaic module in the detection mode 2T→4T of the present invention. The external detection equipment is connected through the OUT terminal. The perovskite top cell module directly receives the detection injection through the first controllable switch. The crystalline silicon bottom cell module works in reverse through a bidirectional DC-DC converter and receives the detection injection through the second controllable switch.

[0018] The symbols in the image are as follows: 1. Junction box; 2. Control board; 3. Controller; 4. Bidirectional DC-DC converter; 5. Switch reconfiguration unit; 51. First controllable switch; 52. Second controllable switch; A. Perovskite top-mounted solar module; B. Crystalline silicon bottom-mounted solar module; C. Perovskite-crystalline silicon tandem photovoltaic module; D. Attachment terminal; E. External detection power supply; F. Inverter. Detailed Implementation

[0019] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0020] Please refer to Figure 1 As shown, a preferred embodiment of the testing device for perovskite-crystalline silicon tandem photovoltaic modules of the present invention includes a junction box 1. The junction box 1 is provided with four input terminals and two output terminals. The four input terminals of the junction box 1 are respectively connected to the positive and negative output terminals of the perovskite top cell module A and the crystalline silicon bottom cell module B through leads. The positive and negative output terminals of the two terminals are the access terminals D when testing the perovskite-crystalline silicon tandem photovoltaic module C.

[0021] Perovskite top-mounted solar module A and crystalline silicon bottom-mounted solar module B are stacked together to form perovskite-crystalline silicon tandem photovoltaic module C. Under normal use, the positive and negative output terminals of the two terminals serve as the output terminals of the perovskite-crystalline silicon tandem photovoltaic module C and are connected to the inverter F. When testing is required, the positive and negative output terminals of the two terminals serve as the input terminals, or testing terminals, of the external testing power supply E of the testing instrument.

[0022] A control board 2 is installed inside junction box 1. A controller 3, a bidirectional DC-DC converter 4, a switch reconfiguration unit 5, and a sampling unit (not shown in the figure) are respectively installed on the control board 2. The controller 3 is connected to the switch reconfiguration unit 5, the bidirectional DC-DC converter 4, and the sampling unit. The sampling unit is used to collect the detection voltage and detection current of the perovskite top-mounted solar cell module A, the detection voltage and detection current of the crystalline silicon bottom-mounted solar cell module B, the access detection voltage and access detection current of the access terminal D, and the current of the bidirectional DC-DC converter 4.

[0023] Please refer to Figure 2 As shown, the switch reconfiguration unit 5 includes a first controllable switch 51 and a second controllable switch 52. The first controllable switch 51 is used to control the connection or disconnection between the positive and negative output terminals of the perovskite top battery module A and the access terminal D. The second controllable switch 52 is used to control the connection or disconnection between the positive and negative output terminals of the crystalline silicon bottom battery module B and the bidirectional DC-DC converter 4.

[0024] The input terminal of the bidirectional DC-DC converter 4 is connected to the positive and negative output terminals of the crystalline silicon bottom battery module B, and its output terminal is connected to the access terminal D. The bidirectional DC-DC converter 4 supports power flow in the power generation direction from the crystalline silicon bottom battery module B to the access terminal D, and also supports power flow in the detection direction from the access terminal D to the crystalline silicon bottom battery module B.

[0025] The first controllable switch 51 and the second controllable switch 52 are both field-effect transistors. For example... Figure 2 As shown, the first controllable switch 51 is a field-effect transistor (FET) Kp, and the second controllable switch 52 is a field-effect transistor (FET) Ks. The interfaces OUT+ and OUT- serve as power output terminals and also as input terminals D for the external detection power supply E. Kp is used to control the connection or disconnection between the perovskite top-mounted solar cell module A and the OUT+ terminal; Ks is used to control the connection or disconnection between the crystalline silicon bottom-mounted solar cell module B and the bidirectional DC-DC converter 4. In actual implementation, the first controllable switch 51 and the second controllable switch 52 can be a single MOSFET, a back-to-back MOSFET, an IGBT, a relay, a solid-state relay, an analog switch, or other controllable switching devices.

[0026] The function of the switch reconfiguration unit 5 is not to perform voltage boosting or bucking, but to change the power path according to the mode switching command output by the controller. When the perovskite-crystalline silicon tandem photovoltaic module C is in power generation mode, Kp and Ks are turned on, allowing the perovskite direct-through branch and the crystalline silicon conversion branch to jointly supply power to the OUT terminal; when the perovskite-crystalline silicon tandem photovoltaic module C is in detection mode, Kp and Ks are turned on or off according to the detection task, allowing the external detection power supply E to be directly injected into the perovskite top cell module A, or injected into the crystalline silicon bottom cell module B through the bidirectional DC-DC converter 4, or simultaneously injected with detection current or detection voltage into both cell modules.

[0027] Please refer to Figure 3 As shown, the bidirectional DC-DC converter 4 includes four field-effect transistors Q1~Q4, two capacitors C1 and C2, and an inductor L1. Field-effect transistors Q1 and Q2 are connected in series and then in parallel with capacitor C1; field-effect transistors Q3 and Q4 are connected in series and then in parallel with capacitor C2; and inductor L1 is connected in series with field-effect transistors Q1 and Q3.

[0028] The bidirectional DC-DC converter 4 can employ a bidirectional synchronous Buck circuit, a bidirectional synchronous Boost circuit, a bidirectional Buck-Boost circuit, a non-inverting bidirectional Buck-Boost circuit, an isolated bidirectional DC-DC circuit, or a combination of the above circuits. Preferably, the bidirectional DC-DC converter 4 adopts a synchronous rectification structure, replacing the unidirectional diode with a controllable switching device, so that the circuit supports power flow in the power generation direction from the crystalline silicon bottom battery module B to the access terminal D, and also supports power flow in the detection direction from the access terminal D to the crystalline silicon bottom battery module B.

[0029] In a preferred embodiment, the bidirectional DC-DC converter 4 is located in the crystalline silicon branch. When the perovskite-crystalline silicon tandem photovoltaic module C is in power generation mode, the output voltage of the crystalline silicon bottom cell module B is boosted, bucked, or buck-boosted by the bidirectional DC-DC converter 4 and then connected in parallel with the direct output of the perovskite top cell module A at interfaces OUT+ and OUT-. When the perovskite-crystalline silicon tandem photovoltaic module C is in detection mode, the bidirectional DC-DC converter 4 operates in reverse, converting the electrical energy input from the external detection power supply E through interfaces OUT+ and OUT- into a detection voltage or detection current suitable for application to the crystalline silicon bottom cell module B.

[0030] Please refer to Figure 4 As shown, when the perovskite-crystalline silicon tandem photovoltaic module C is in power generation mode, the perovskite top cell module A and the crystalline silicon bottom cell module B serve as power input sources, and the positive and negative output terminals of the two terminals are connected to the inverter F as the output terminals of the perovskite-crystalline silicon tandem photovoltaic module C. Controller 3 controls the field-effect transistor Kp (i.e., the first controllable switch 51) to conduct, so that the positive terminal of the perovskite top cell module A is connected to the interface OUT+ via Kp, and the negative terminal of the perovskite top cell module A is connected to the interface OUT-, thereby forming a perovskite direct output branch. Controller 3 simultaneously controls the field-effect transistor Ks (i.e., the second controllable switch 52) to conduct, so that the crystalline silicon bottom cell module B is connected to the bidirectional DC-DC converter 4. The bidirectional DC-DC converter 4 operates with a fixed duty cycle or a calibrated duty cycle, converting the output voltage of the crystalline silicon bottom cell module B to the target range that matches the output voltage of the perovskite top cell module A, and outputting in parallel with the perovskite direct branch at interfaces OUT+ and OUT-.

[0031] Since perovskite top-mounted solar module A typically outputs relatively high voltage and low current, while crystalline silicon bottom-mounted solar module B typically outputs relatively low voltage and high current, in a preferred embodiment, a bidirectional DC-DC converter 4 is located in the crystalline silicon branch and operates as a boost or buck-boost circuit when the perovskite-crystalline silicon tandem photovoltaic module C is in power generation mode. The output voltage of the crystalline silicon bottom-mounted solar module B, after being converted by the bidirectional DC-DC converter 4, is matched with the output voltage of the perovskite top-mounted solar module A and connected in parallel with the perovskite direct-through branch at the input terminal D. The fixed duty cycle can then be determined according to the following relationship: D≈1-V Si_target / V Pero_target , Where D is the fixed duty cycle of the bidirectional DC-DC converter 4 in power generation mode, and V Si_target V is the target operating voltage for crystalline silicon bottom cell module B. Pero_target The target operating voltage is the perovskite top-mounted solar cell module A. The target operating voltage can be the maximum power point voltage, an approximate maximum power point voltage estimated from the open-circuit voltage, a target voltage obtained from historical test data, or a target voltage determined by the module parameter table.

[0032] When the perovskite-crystalline silicon tandem photovoltaic module C is in power generation mode, the interface circuit preferably does not execute continuous module-level MPPT perturbation algorithms for each cell module, but instead operates according to a preset or calibrated fixed duty cycle. The downstream inverter, power optimizer, or system-level power conversion device can then perform system-level MPPT on the total output at the OUT terminal. This approach reduces module-level control complexity and power loss while preserving two-terminal compatibility for power generation connection.

[0033] Please refer to Figure 5 As shown, when the perovskite-crystalline silicon tandem photovoltaic module C is in detection or maintenance mode, the external detection power supply E, EL test power supply, IV test equipment, or the inverter's built-in detection module are connected to interfaces OUT+ and OUT- (i.e., access terminal D). After the controller 3 recognizes the external detection power supply E connection, test command, preset voltage pulse, or communication handshake signal, it causes the interface circuit to enter detection mode.

[0034] When the perovskite-crystalline silicon tandem photovoltaic module C is in detection mode, interfaces OUT+ and OUT- serve as test access terminals D. When controller 3 controls the MOSFET Kp to conduct, the positive terminal of the external detection power supply E is directly connected to the positive terminal of the perovskite top-mounted solar module A via interfaces OUT+ and Kp, and the negative terminal of the external detection power supply E is connected to the negative terminal of the perovskite top-mounted solar module A via interface OUT-, thus forming a direct detection injection path for the perovskite top-mounted solar module A. This path is suitable for dark-state current injection, EL detection, IV scanning, leakage detection, aging status assessment, and other electrical tests of the perovskite top-mounted solar module A.

[0035] When controller 3 controls the MOSFET Ks to conduct and controls the bidirectional DC-DC converter 4 to operate in reverse, the electrical energy input from the external detection power supply E via interfaces OUT+ and OUT- first enters the bidirectional DC-DC converter 4, and then is injected into the crystalline silicon bottom cell module B via Ks. The bidirectional DC-DC converter 4 converts the input detection voltage or current of the external detection power supply E into a detection voltage or current suitable for the crystalline silicon bottom cell module B according to the detection task. This path is suitable for IV scanning, EL detection, series resistance diagnosis, parallel resistance diagnosis, leakage detection, and other electrical detection of the crystalline silicon bottom cell module B.

[0036] In the single-detection sub-mode of perovskite top-mounted solar module A, Kp is on, Ks is off, or the bidirectional DC-DC converter 4 stops outputting, and external detection power is mainly injected into perovskite top-mounted solar module A. In the single-detection sub-mode of crystalline silicon bottom-mounted solar module B, Ks is on, Kp is off, or remains at a safe bias, and external detection power is injected into crystalline silicon bottom-mounted solar module B via bidirectional DC-DC converter 4. In the dual-branch joint detection sub-mode, Kp and Ks are on simultaneously, and the external detection current or voltage is distributed to perovskite top-mounted solar module A and crystalline silicon bottom-mounted solar module B according to a preset ratio or detection formula.

[0037] Please refer to again Figure 5 As shown, when the perovskite-crystalline silicon tandem photovoltaic module C is in detection or maintenance mode, the externally input detection power can be distributed to the perovskite top cell module A and the crystalline silicon bottom cell module B according to the detection task. The detection current I of the perovskite top cell module A... pero_ref The detection current I of the crystalline silicon bottom cell module B si_ref Determined according to the following relationship: I pero_ref = α ·I test , I si_ref =(1- α )·I test ; In the formula, I test The access detection current input from the access terminal, α This is the current distribution coefficient, and its value can be 0 ≤ α ≤1; when α When =1, the detection current I is connected. test All or most of the allocation is to perovskite top-mounted solar module A; when α When =0, the detection current I is connected. test All or most of the allocation is to crystalline silicon bottom cell module B; when 0 < α When <1, the detection current I is connected. testThe current is simultaneously distributed to perovskite top-mounted solar module A and crystalline silicon bottom-mounted solar module B according to a preset ratio. Controller 3 generates a current distribution coefficient α based on external detection commands, module status, detection tasks, and safety constraints.

[0038] Since the perovskite branch is a direct detection path in the preferred embodiment, the controller 3 can achieve detection current distribution through the conduction state of Kp, the external detection source setting value, the voltage and current sampling feedback of the perovskite branch, and the closed-loop adjustment of the silicon branch absorption current by the bidirectional DC-DC converter 4. When more precise control of the perovskite branch current is required, Kp can also be a controllable switching device with current limiting, PWM control, or linear control capabilities.

[0039] The current distribution coefficient α can be dynamically determined based on the testing task, the rated current of the battery module, the area of ​​the battery module, the current density, the EL testing brightness requirements, the IV scan curve, the historical aging state of the module, the temperature state, or safety limits. The controller 3 can also employ one or more of the following: constant current control, constant voltage control, constant power control, scan control, or pulse control, to meet different testing tasks.

[0040] When the perovskite-crystalline silicon tandem photovoltaic module C is in detection or maintenance mode, the controller 3 can also set independent voltage limiting, current limiting, and time limiting conditions. For example, the perovskite top cell module A has a first detection voltage limit, a first detection current limit, and a first detection duration limit; the crystalline silicon bottom cell module B has a second detection voltage limit, a second detection current limit, and a second detection duration limit. When any detection parameter exceeds the corresponding threshold, the controller 3 reduces the detection power, disconnects the corresponding branch, or enters protection mode.

[0041] This invention also discloses a testing method for perovskite-crystalline silicon tandem photovoltaic modules. When testing the perovskite-crystalline silicon tandem photovoltaic modules, the testing device for perovskite-crystalline silicon tandem photovoltaic modules as described above is used. The testing method includes the following steps: Connect the testing instrument's input current or input voltage to the junction box of the perovskite-crystalline silicon tandem photovoltaic module testing device, and perform the following tests according to the requirements of the testing items: When it is necessary to test the perovskite top solar cell module A separately, the controller controls the first controllable switch to be turned on and the second controllable switch to be turned off. The detection current or detection voltage is connected to the positive and negative output terminals of the perovskite top solar cell module A separately to perform the corresponding test on the perovskite top solar cell module A.

[0042] When it is necessary to test the crystalline silicon bottom cell module B separately, the controller controls the first controllable switch to close and the second controllable switch to open. At the same time, it controls the bidirectional DC-DC converter to work in reverse. The detection current or detection voltage is connected to the positive and negative output terminals of the crystalline silicon bottom cell module B separately through the bidirectional DC-DC converter to perform the corresponding test on the crystalline silicon bottom cell module B.

[0043] When both perovskite top-mounted solar module A and crystalline silicon bottom-mounted solar module B need to be tested simultaneously, the controller activates both the first and second controllable switches, and simultaneously controls the bidirectional DC-DC converter to operate in reverse. A detection current or voltage is applied to the positive and negative output terminals of perovskite top-mounted solar module A and crystalline silicon bottom-mounted solar module B according to a set ratio, allowing for corresponding testing of each module. One of the detection current or voltage inputs is connected to the positive and negative output terminals of crystalline silicon bottom-mounted solar module B via the bidirectional DC-DC converter.

[0044] Specifically, the testing items include at least one of IV scanning, EL testing, series resistance diagnosis, parallel resistance diagnosis, and leakage current detection.

[0045] The detection device and method for perovskite-crystalline silicon tandem photovoltaic modules of the present invention also have the following characteristics: 1. This invention, through Kp, Ks, and a bidirectional DC-DC converter 4 located in the crystalline silicon branch, enables the four-terminal perovskite-silicon tandem photovoltaic module C to have different interface configurations in different operating modes. In power generation mode, the perovskite top cell module A outputs directly, while the crystalline silicon bottom cell module B outputs after matching via the bidirectional DC-DC converter 4. Both converge at interfaces OUT+ and OUT-, making the module appear as a typical two-terminal module. In detection mode, external detection equipment inputs detection power through the same interfaces OUT+ and OUT-. The interface circuit is reconstructed to form a direct detection path for the perovskite module and a reverse detection path for the crystalline silicon module via the bidirectional DC-DC converter 4, achieving reverse reconstruction from two-terminal to four-terminal.

[0046] 2. This invention does not configure independent power converters for both the perovskite top-mounted solar cell module A and the crystalline silicon bottom-mounted solar cell module B. Instead, in a preferred embodiment, the perovskite high-voltage branch is directly connected to an external two-terminal bus via Kp, with a bidirectional DC-DC converter 4 configured only in the crystalline silicon branch for voltage matching. This structure reduces the number of power devices and conversion losses, while simultaneously solving the parallel matching problem between the crystalline silicon low-voltage branch and the perovskite high-voltage branch.

[0047] 3. In this invention, when the perovskite-silicon tandem photovoltaic module C is in detection mode, it is not necessary to continuously bring out four detection terminals. Instead, the same interfaces OUT+ and OUT- during power generation are used to detect the two internal battery modules. The perovskite top battery module A receives the detection injection through a direct path, while the crystalline silicon bottom battery module B receives the detection injection through a reverse conversion path via a bidirectional DC-DC converter 4. The controller 3 can also distribute the input detection current to the two battery modules according to the detection task in the ratio of α and 1-α.

[0048] 4. This invention combines detection functionality with power generation control. In detection mode, controller 3 acquires the open-circuit voltage, specified operating point voltage, IV curve, or approximate maximum power point voltage of perovskite top-mounted solar module A and crystalline silicon bottom-mounted solar module B, respectively. Based on this, it updates the fixed duty cycle or voltage and current limiting thresholds in the power generation mode. Thus, without performing continuous MPPT at the module level, the fixed duty cycle is periodically or on demand calibrated using the detection results, thereby compensating for voltage matching deviations caused by module aging, environmental changes, or parameter drift, and improving long-term power generation efficiency.

[0049] In summary, this invention does not merely convert a four-terminal tandem module into a two-terminal output; rather, it proposes a bidirectional power interface architecture that reuses power generation, detection, and calibration: during power generation, it achieves a fixed duty cycle output from 4T to 2T; during detection, it achieves layered detection from 2T to 4T, and uses the detection results to reverse-calibrate the fixed duty cycle in power generation mode. Simultaneously, it enables the perovskite-crystalline silicon tandem photovoltaic module C to convert its internal four-terminal structure into an external two-terminal output in power generation mode, ensuring compatibility with existing inverters; and in detection or maintenance mode, it can utilize the same external two-port for reverse power supply, reconstructing detection paths that connect the perovskite top cell module A and the crystalline silicon bottom cell module B respectively.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A testing device for a perovskite-crystalline silicon tandem photovoltaic module, comprising a junction box, wherein four input terminals and two output terminals are respectively provided on the junction box, and the four input terminals of the junction box are respectively connected to the positive and negative output terminals of the perovskite top cell module and the crystalline silicon bottom cell module via leads, characterized in that, The positive and negative output terminals of the two terminals are the access terminals for testing the perovskite-crystalline silicon tandem photovoltaic module. A control board is set inside the junction box, and a controller, a bidirectional DC-DC converter, a switch reconfiguration unit, and a sampling unit are respectively set on the control board. The controller is connected to the switch reconfiguration unit, the bidirectional DC-DC converter, and the sampling unit. The switch reconfiguration unit includes a first controllable switch and a second controllable switch. The first controllable switch is used to control the connection or disconnection between the positive and negative output terminals of the perovskite top cell module and the access terminal. The second controllable switch is used to control the connection or disconnection between the positive and negative output terminals of the crystalline silicon bottom cell module and the bidirectional DC-DC converter. The sampling unit is used to collect the detection voltage and detection current of the perovskite top cell module, the detection voltage and detection current of the crystalline silicon bottom cell module, and the access detection voltage and access detection current of the access terminal. The bidirectional DC-DC converter supports power flow in both the power generation direction from the crystalline silicon bottom cell module to the access terminal and the detection direction from the access terminal to the crystalline silicon bottom cell module. The detection current I of the perovskite top solar cell module pero_ref The detection current I of the crystalline silicon bottom cell module si_ref Determined according to the following relationship: I pero_ref = α ·I test , I si_ref =(1- α )·I test ; In the formula, I test The access detection current input from the access terminal, α This is the current distribution coefficient, with a value range of 0 ≤ α ≤1; when α When =1, the entire detection current is distributed to the perovskite top cell module; when α When the current is 0, the entire detection current is allocated to the crystalline silicon bottom battery module. When 0 < α When the current is less than 1, the detection current is simultaneously distributed to the perovskite top cell module and the crystalline silicon bottom cell module according to a preset ratio.

2. The testing device for a perovskite-crystalline silicon tandem photovoltaic module as described in claim 1, characterized in that, The bidirectional DC-DC converter includes four field-effect transistors Q1 to Q4, two capacitors C1 and C2, and an inductor L1. Field-effect transistors Q1 and Q2 are connected in series and then in parallel with capacitor C1; field-effect transistors Q3 and Q4 are connected in series and then in parallel with capacitor C2; and inductor L1 is connected in series with field-effect transistors Q1 and Q3.

3. The testing device for a perovskite-crystalline silicon tandem photovoltaic module as described in claim 1, characterized in that, The first controllable switch and the second controllable switch are both field-effect transistors.

4. A method for testing a perovskite-crystalline silicon tandem photovoltaic module, characterized in that, When testing perovskite-crystalline silicon tandem photovoltaic modules, the testing device for perovskite-crystalline silicon tandem photovoltaic modules as described in any one of claims 1 to 3 was used, and the testing method includes the following steps: Connect the testing instrument to the input terminal of the junction box of the perovskite-crystalline silicon tandem photovoltaic module testing device, and perform the following tests according to the requirements of the testing items: When it is necessary to test the perovskite top solar cell module separately, the controller controls the first controllable switch to be turned on and the second controllable switch to be turned off. The detection current or detection voltage is connected to the positive and negative output terminals of the perovskite top solar cell module separately to perform the corresponding test on the perovskite top solar cell module. When it is necessary to test the crystalline silicon bottom battery module separately, the controller controls the first controllable switch to close and the second controllable switch to open. At the same time, it controls the bidirectional DC-DC converter to work in reverse. The detection current or detection voltage is connected to the positive and negative output terminals of the crystalline silicon bottom battery module separately through the bidirectional DC-DC converter to perform the corresponding test on the crystalline silicon bottom battery module. When it is necessary to test both the perovskite top-mounted solar cell module and the crystalline silicon bottom-mounted solar cell module simultaneously, the controller controls the first and second controllable switches to turn on at the same time, and simultaneously controls the bidirectional DC-DC converter to work in reverse. The detection current or detection voltage is connected to the positive and negative output terminals of the perovskite top-mounted solar cell module and the crystalline silicon bottom-mounted solar cell module according to the set ratio, so as to perform corresponding tests on the perovskite top-mounted solar cell module and the crystalline silicon bottom-mounted solar cell module respectively.

5. The testing method for perovskite-crystalline silicon tandem photovoltaic modules as described in claim 4, characterized in that, The testing items include at least one of the following: IV scanning, EL testing, series resistance diagnosis, parallel resistance diagnosis, and leakage current detection.

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