A laminated photovoltaic cell and its power intelligent controller, a photovoltaic power generation system and a control method thereof

Abstract

The application discloses a laminated photovoltaic unit and a power intelligent controller thereof, a photovoltaic power generation system and a control method thereof. The power intelligent controller comprises at least one DC-DC converter, an input end of the DC-DC converter is connected with a total output end of one of the first battery layer or the second battery layer; the DC-DC converter performs an MPPT algorithm on the connected one of the battery layers and carries out direct-current voltage conversion, converts the total output voltage of the connected one of the battery layers to match the total output voltage of the other one of the battery layers; and an output end of the DC-DC converter is connected in parallel with a total output end of the other one of the battery layers to form a single output port. Through unified voltage boosting or voltage reducing optimization of one of the battery layers, voltage accurate matching and direct parallel connection with the other one of the battery layers are realized, a single output interface is formed, the existing photovoltaic system can be compatible, the structure is simplified, the control is simple, the system cost is effectively reduced, and the mass production feasibility and operation reliability are improved.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power generation technology, and in particular to a multilayer photovoltaic unit and its power controller, a photovoltaic power generation system and its control method. Background Technology

[0002] With the rapid development of photovoltaic technology, the mass production conversion efficiency of monocrystalline silicon photovoltaic cells has approached its Shockley-Quisser theoretical limit, leaving limited room for further improvement. Perovskite-crystalline silicon tandem photovoltaic cells, by combining a wide-bandgap perovskite top cell with a narrow-bandgap crystalline silicon bottom cell, can fully absorb energy from different wavelengths of the solar spectrum, achieving a theoretical efficiency exceeding 45%, and represent the core development direction of next-generation photovoltaic technology.

[0003] Currently, perovskite-crystalline silicon tandem solar cells are mainly divided into two-terminal tandem structures and four-terminal tandem structures. Two-terminal tandem structures require strict current matching between the top and bottom cells. In actual outdoor conditions, spectral shifts, temperature fluctuations, and shading can lead to severe current mismatch, resulting in power loss and even hot spot effects, leading to insufficient reliability in engineering applications. The four-terminal stacked structure electrically isolates the two sub-cells, avoiding the current matching problem and enabling independent maximum power point tracking (MPPT) for both sub-cells, maximizing power generation efficiency. However, it has core industry pain points: for example, crystalline silicon bottom cells have low-voltage, high-current characteristics (single-cell open-circuit voltage 0.6-0.7V, and the conventional output after series connection is 30-50V), while perovskite top cells can achieve high-voltage output (50-200V) by flexibly adjusting the number of cells in series. The output voltage difference between the two is huge, and they cannot be directly connected in parallel. A dual-path independent output architecture must be adopted, requiring the configuration of dual-path MPPT inverters or two independent inverters. It is not compatible with existing mainstream single-path input photovoltaic inverters, which greatly increases the system BOS cost and seriously restricts the large-scale engineering application of stacked modules.

[0004] To address the aforementioned issues, existing technologies propose a scheme where each crystalline silicon sub-cell is equipped with a separate micro power optimizer, which is then boosted, connected in series, and finally linked in parallel with the perovskite layer. However, this scheme requires dozens of power optimizers to match the number of crystalline silicon sub-cells, resulting in high system cost, complex packaging and integration, numerous potential failure points, and low reliability, making it unsuitable for mass-produced tandem modules. Therefore, there is an urgent need for a perovskite-crystalline silicon tandem photovoltaic solution that can solve the voltage mismatch problem of four-terminal tandem cells, reduce costs and increase efficiency, and is compatible with existing photovoltaic systems. Summary of the Invention

[0005] The purpose of this invention is to provide a tandem photovoltaic unit and its power intelligent controller, a photovoltaic power generation system and its control method. It abandons the power optimization scheme of the neutron cell level in the existing technology, and achieves precise voltage matching and direct parallel connection with the voltage of the other cell layer by uniformly boosting or bucking one of the cell layers. This solves the voltage mismatch of the tandem photovoltaic unit, simplifies the system architecture, and can be compatible with existing photovoltaic systems through single-path output, thereby reducing system costs and improving mass production feasibility and operational reliability.

[0006] To address the aforementioned technical problems, embodiments of the present invention provide a technical solution as follows: A power intelligent controller for a tandem photovoltaic unit, the tandem photovoltaic unit comprising a first battery layer and a second battery layer; the power intelligent controller includes a first input port, a second input port, and an output port; the first input port is connected to the total output terminal of the first battery layer, and the second input port is connected to the total output terminal of the second battery layer; the power intelligent controller further includes at least one DC-DC converter, the DC-DC converter being disposed on the power path between the first input port or the second input port and the output port; the DC-DC converter performs an MPPT algorithm and DC voltage conversion on the connected battery layer, converting the total output voltage of the connected battery layer to match the total output voltage of the other battery layer; and the output terminal of the DC-DC converter is connected in parallel with the total output terminal of the other battery layer to form a single output port.

[0007] Furthermore, the DC-DC converter is a boost DC-DC converter, which is connected to one of the battery layers with a lower total output voltage, and boosts the total output voltage of that battery layer to match the total output voltage of the other battery layer with a higher voltage.

[0008] Furthermore, the DC-DC converter is a step-down DC-DC converter, which is connected to one of the battery layers with a higher total output voltage, and steps down the total output voltage of that battery layer to match the total output voltage of the other battery layer with a lower voltage.

[0009] Furthermore, there are multiple DC-DC converters. The input terminals of the multiple DC-DC converters are connected in parallel and then connected to the total output terminal of one of the first battery layer or the second battery layer. The output terminals of the multiple DC-DC converters are connected in parallel and then connected to the total output terminal of another battery layer.

[0010] Furthermore, the DC-DC converter includes a main control module and a power conversion module. The main control module adjusts the PWM duty cycle of the power switching transistor in the power conversion module to synchronously realize the boost or buck conversion, maximum power point tracking, and total output voltage matching control with the battery layer connected to the input terminal of the DC-DC converter.

[0011] Furthermore, the DC-DC converter also integrates a fault protection module, which includes at least one of the following: input reverse connection protection, input overcurrent protection, output overvoltage protection, overtemperature protection, short circuit shutdown, and reverse current blocking unit.

[0012] To address the aforementioned technical problems, the present invention also provides a stacked photovoltaic unit, comprising a first battery layer and a second battery layer stacked together, and a power controller as described in any of the preceding claims. The DC-DC converter of the power controller performs the MPPT algorithm and DC voltage conversion on one connected battery layer, converting the total output voltage of the connected battery layer to match the total output voltage of the other battery layer. The output terminal of the DC-DC converter is connected in parallel with the total output terminal of the other battery layer to form a single output port of the stacked photovoltaic unit.

[0013] Furthermore, the first battery layer is a crystalline silicon battery layer, which is formed by connecting multiple crystalline silicon sub-cells in series and / or parallel, and is provided with a total output terminal for the crystalline silicon battery layer; the second battery layer is a perovskite battery layer, which is formed by connecting multiple perovskite sub-cells in series and / or parallel, and is provided with a total output terminal for the perovskite battery layer.

[0014] Furthermore, the total output voltage of the perovskite solar cell layer is higher than that of the crystalline silicon solar cell layer. The power controller has a built-in boost DC-DC converter, and the input terminal of the boost DC-DC converter is electrically connected to the total output terminal of the crystalline silicon solar cell layer. The boost topology circuit is used to boost the total output voltage of the crystalline silicon solar cell layer to a voltage level that matches the total output voltage of the perovskite solar cell layer.

[0015] Furthermore, the total output voltage of the perovskite solar cell layer is higher than that of the crystalline silicon solar cell layer. The power controller has a built-in buck DC-DC converter, and the input terminal of the buck DC-DC converter is electrically connected to the total output terminal of the perovskite solar cell layer. The buck topology circuit is used to step down the total output voltage of the perovskite solar cell layer to a voltage level that matches the total output voltage of the crystalline silicon solar cell layer.

[0016] To address the aforementioned technical problems, the present invention also provides a photovoltaic power generation system, comprising at least one tandem photovoltaic unit as described in any of the preceding claims, a DC combiner unit, and a photovoltaic inverter; each single output port of the tandem photovoltaic unit is connected to the DC combiner unit, the output terminal of the DC combiner unit is electrically connected to the DC side of the photovoltaic inverter, and the AC side of the photovoltaic inverter is connected to the power grid or an AC load.

[0017] Furthermore, the single output ports of two or more of the stacked photovoltaic units are connected to the DC combiner unit in series and / or parallel, and the DC combiner unit has a built-in protection circuit.

[0018] Furthermore, it also includes a central controller, which is communicatively connected to the power controller in the tandem photovoltaic unit and the photovoltaic inverter, respectively, for realizing the coordinated control and status monitoring of the photovoltaic power generation system.

[0019] To address the aforementioned technical problems, this invention also provides a photovoltaic power generation system control method, comprising the following steps: System initialization: establishing a DC bus voltage, acquiring the real-time voltage of the total output terminal of the battery layer not connected to the input terminal of the DC-DC converter through the power intelligent controller in the tandem photovoltaic unit, and setting an initial output voltage matching value; Synchronous real-time control: acquiring the voltage and current of the total output terminal of the battery layer connected to the input terminal of the DC-DC converter in real time, executing the MPPT algorithm, and controlling the power intelligent controller to make the battery layer connected to one path operate at the maximum power point; using the real-time output voltage of the total output terminal of the other battery layer as the target value, dynamically adjusting the output voltage of the DC-DC converter to keep the output voltage of the DC-DC converter consistent with the total output voltage of the other battery layer in real time, achieving non-circulating current parallel output; Cooperative power optimization control: adjusting the MPPT tracking parameters and / or the DC bus voltage according to the system operating data, so that the tandem photovoltaic units connected in parallel operate at the global maximum power point.

[0020] Furthermore, it also includes fault protection and emergency handling procedures, real-time monitoring of system operating status, and when a fault occurs, shutting down the power conversion circuit of the faulty unit and isolating the fault, triggering an alarm and waiting for automatic restart.

[0021] Furthermore, the MPPT algorithm is a composite algorithm combining the incremental conductance method under normal operating conditions and the variable step size perturbation observation method under sudden irradiation conditions; the real-time voltage matching control adopts closed-loop PI regulation, using the total output voltage of the battery layer not connected to the input terminal of the DC-DC converter as the reference value and the real-time output voltage of the power controller as the feedback value, dynamically correcting the PWM duty cycle so that the voltage deviation is less than the preset threshold.

[0022] The tandem photovoltaic unit and its power controller, photovoltaic power generation system and its control method provided by this invention, compared with the prior art, the power controller executes the MPPT algorithm on a single battery layer through a DC-DC converter, and converts its total output voltage to DC to match the total output voltage of another battery layer, connecting them in parallel to form a single output port. It abandons the existing sub-cell level power optimization scheme and adopts unified boost optimization of the entire sub-cell string. Compared with the power optimizer used in the existing scheme, the number of power optimizers is greatly reduced, which can effectively reduce system cost and packaging integration difficulty. The structure is simplified and the control is simple. It can not only solve the problem of voltage mismatch and difficulty in parallel connection of 4T architecture tandem photovoltaic units in the prior art, but also be compatible with existing photovoltaic systems through a single output port, reducing system cost. It can effectively improve the feasibility of mass production and the reliability of operation of tandem photovoltaic units. In particular, the DC-DC converter, through its main control module, adjusts the PWM duty cycle of the power switching transistors in the power conversion module to simultaneously achieve boost or buck conversion, maximum power point tracking, and total output voltage matching control with the battery layer connected to the DC-DC converter input. This ensures precise voltage matching between the two battery layers. Combined with real-time closed-loop voltage tracking control, this enables direct, non-circulating current parallel connection of the two outputs, avoiding power loss caused by voltage mismatch. Furthermore, the tandem photovoltaic unit's battery layer, connected via a power controller, outputs a single DC power supply, which can be directly connected to existing mainstream single-input photovoltaic inverters without the need for customized dual-MPPT inverters. This ensures full compatibility with existing photovoltaic power plant architectures, equipment, and construction specifications, significantly lowering the barrier to large-scale application of tandem photovoltaic units. By implementing system initialization, synchronous real-time control, and collaborative power optimization control in the photovoltaic power generation system control method, the core advantages of the four-terminal stacked photovoltaic unit are retained while achieving single-path output. The single-path battery layer achieves independent MPPT through a DC-DC converter, and the other battery layer achieves MPPT through a photovoltaic inverter. It can adapt to complex outdoor conditions such as spectral shift, temperature fluctuation, and partial shading, effectively improving the power generation revenue of the photovoltaic power generation system. Attached Figure Description

[0023] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings represent similar elements. Unless otherwise stated, the figures in the drawings do not constitute a limitation on scale.

[0024] Figure 1 This is a schematic diagram of the stacked photovoltaic unit structure in the embodiment of the present invention with the DC-DC converter connected to the first battery layer; Figure 2 This is a schematic diagram of the stacked photovoltaic unit structure in the embodiment of the present invention with the DC-DC converter connected to the second battery layer; Figure 3This is a schematic diagram of the Boost circuit topology of the power controller in an embodiment of the present invention; Figure 4 This is a schematic diagram of the Buck circuit topology of the power controller in an embodiment of the present invention; Figure 5 This is a schematic diagram of the overall structure of the photovoltaic power generation system in an embodiment of the present invention; Figure 6 This is a flowchart of the photovoltaic power generation system control method in an embodiment of the present invention.

[0025] Explanation of reference numerals in the attached figures: 10, Power Intelligent Controller; 101, First Input Port; 102, Second Input Port; 103, Output Port; 104, DC-DC Converter; 11, Main Control Module; 12, Power Conversion Module; 13, Fault Protection Module; 14, Drive Module; 15, Sampling Module; 16, Input Filter Module; 17, Output Filter Module; 18, Communication Module; 20, Stacked Photovoltaic Unit; 21, First Battery Layer; 22, Second Battery Layer; 30, Photovoltaic Power Generation System; 31, Central Controller; 32, DC Combiner Unit; 33, Photovoltaic Inverter. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the various embodiments of this invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this invention to facilitate a better understanding of this application. However, the technical solutions claimed in the claims of this application can be implemented even without these technical details and with various variations and modifications based on the following embodiments.

[0027] like Figure 1-2As shown, one embodiment of the present invention relates to a power controller for a stacked photovoltaic unit 20. The stacked photovoltaic unit 20 includes a first battery layer 21 and a second battery layer 22 stacked together. The power controller 10 includes a first input port 101, a second input port 102, and an output port 103. The first input port 101 is connected to the total output terminal of the first battery layer 21, and the second input port 102 is connected to the total output terminal of the second battery layer 22. The power controller 10 also includes at least one DC-DC converter 104, which is disposed on a power path between one of the first input port 101 or the second input port 102 and the output port 103. The DC-DC converter 104 performs the MPPT algorithm on the connected battery layer and performs DC voltage conversion to convert the total output voltage of the connected battery layer to match the total output voltage of the other battery layer. The output terminal of the DC-DC converter 104 is connected in parallel with the total output terminal of the other battery layer to form a single output port of the stacked photovoltaic unit. The power controller 10 performs the MPPT algorithm on a single battery layer via a DC-DC converter 104 and matches it with the total output voltage of another battery layer to form a single output port 103. This eliminates the need for existing sub-cell level power optimization schemes and adopts unified boost optimization for the entire sub-cell string. Compared to existing schemes, this significantly reduces the number of power optimizers used, effectively lowering system costs and simplifying packaging and integration. The simplified structure and easy control not only solve the problem of voltage mismatch in the existing 4T architecture tandem photovoltaic units 20, making parallel connection difficult, but also ensure compatibility with existing photovoltaic systems through a single output port, reducing system costs and effectively improving the feasibility of mass production and operational reliability of the tandem photovoltaic units 20. Furthermore, the power controller 10 can be directly integrated into the junction box or substrate of the tandem photovoltaic unit 20 without additional installation space, adapting to existing module mass production processes and offering strong convenience for engineering applications.

[0028] like Figure 1As shown, in one embodiment, a power controller is provided for a tandem photovoltaic (PV) unit 20. The PV unit 20 includes a first battery layer 21 and a second battery layer 22 stacked together. The power controller 10 includes a DC-DC converter 104, which is a boost DC-DC converter connected to a battery layer with a lower total output voltage. The boost converter boosts the total output voltage of the battery layer to match the total output voltage of the other battery layer with a higher voltage. In one example, the total output voltage of the first battery layer 21 is lower than the total output voltage of the second battery layer 22. The first input port 101 of the power controller 10 is connected to the total output of the first battery layer 21, and the second input port 102 is connected to the total output of the second battery layer 22. The boost DC-DC converter 104 is disposed on the power path between the first input port 101 and the output port 103. The boost DC-DC converter adopts a boost topology to boost the total output voltage of the first battery layer 21 to a voltage level that matches the total output voltage of the second battery layer 22.

[0029] like Figure 2 As shown, in one embodiment, a power controller is provided for a tandem photovoltaic (PV) unit 20. The PV unit 20 includes a first battery layer 21 and a second battery layer 22 stacked together. The power controller 10 includes a DC-DC converter, which is a buck DC-DC converter connected to a battery layer with a higher total output voltage. The buck converter steps down the total output voltage of the battery layer to match the total output voltage of the other battery layer with a lower voltage. In one example, the total output voltage of the second battery layer 22 is higher than the total output voltage of the first battery layer 21. The first input port 101 of the power controller 10 is connected to the total output of the first battery layer 21, and the second input port 102 is connected to the total output of the second battery layer 22. A buck DC-DC converter 104 is disposed on the power path between the second input port 102 and the output port 103. The buck DC-DC converter adopts a Buck topology to step down the total output voltage of the second battery layer 22 to a voltage level that matches the total output voltage of the first battery layer 21.

[0030] In one embodiment, a power controller 10 is provided, which integrates multiple DC-DC converters 104. The input terminals of the multiple DC-DC converters 104 are connected in parallel and are connected to the total output terminal of one of the first battery layer 21 or the second battery layer 22. The output terminals of the multiple DC-DC converters 104 are connected in parallel and are connected to the total output terminal of the other battery layer. A current sharing control unit is provided among the multiple DC-DC converters to realize the equal distribution of the output current of the multiple channels.

[0031] like Figure 3-4As shown, one embodiment relates to a power controller. Figure 3 The diagram shown is a schematic of the Boost converter circuit topology used in the boost DC-DC converter 104. Figure 4 The diagram shows a schematic of the Buck converter circuit topology used in a buck-type DC-DC converter. The DC-DC converter 104 includes an input filter module 16, a power conversion module 12, an output filter module 17, a sampling module 15, a main control module 11, a drive module 14, and a communication module 18. The power conversion module 12 includes a power switch, an inductor, and a freewheeling diode. The main control module 11 adjusts the PWM duty cycle of the power switch in the power conversion module 12 to synchronously achieve boost or buck conversion, maximum power point tracking, and total output voltage matching control with another battery layer connected to the input of the DC-DC converter 104. Preferably, the DC-DC converter 104 also integrates a fault protection module 13, which includes at least one of the following: input reverse connection protection, input overcurrent protection, output overvoltage protection, overtemperature protection, short-circuit shutdown, and reverse current blocking units.

[0032] like Figure 1-2 As shown, one embodiment of the present invention relates to a stacked photovoltaic unit, including a first battery layer 21 and a second battery layer 22 stacked together, and a power controller 10 as described above. The total output terminal of the first battery layer 21 is electrically connected to the first input port 101 of the power controller 10, and the total output terminal of the second battery layer 22 is electrically connected to the second input port 102 of the power controller 10. The DC-DC converter 104 of the power controller 10 performs the MPPT algorithm and DC voltage conversion on the connected battery layer, converting the total output voltage of the connected battery layer to match the total output voltage of the other battery layer. The output terminal of the DC-DC converter 104 is connected in parallel with the total output terminal of the other battery layer to form a single output port of the stacked photovoltaic unit 20.

[0033] One embodiment relates to a tandem photovoltaic unit, wherein the first cell layer 21 is a crystalline silicon cell layer, formed by connecting multiple crystalline silicon sub-cells in series and / or parallel, and has a total output terminal for the crystalline silicon cell layer; the second cell layer 22 is a perovskite cell layer, formed by connecting multiple perovskite sub-cells in series and / or parallel, and also has a total output terminal for the perovskite cell layer. In one example, the total output voltage of the perovskite cell layer is higher than the total output voltage of the crystalline silicon cell layer. The power controller 10 is a boost-type power controller 10, which has a built-in boost-type DC-DC converter. The input terminal of the boost-type DC-DC converter is electrically connected to the total output terminal of the crystalline silicon cell layer. A boost topology circuit is used to boost the total output voltage of the crystalline silicon cell layer to a voltage level that matches the total output voltage of the perovskite cell layer. In another example, the total output voltage of the perovskite solar cell layer is higher than the total output voltage of the crystalline silicon solar cell layer. The power controller 10 is a buck power controller 10, which has a built-in buck DC-DC converter. The input terminal of the buck DC-DC converter is electrically connected to the total output terminal of the perovskite solar cell layer. The buck topology circuit is used to step down the total output voltage of the perovskite solar cell layer to a voltage level that matches the total output voltage of the crystalline silicon solar cell layer.

[0034] like Figure 5 As shown, one embodiment of the present invention relates to a photovoltaic power generation system, including at least one tandem photovoltaic unit 20 as described above, a DC combiner unit 32, a photovoltaic inverter 33, and a central controller 31. Each single output port of the tandem photovoltaic unit 20 is connected to the DC combiner unit 32, and the output terminal of the DC combiner unit 32 is electrically connected to the DC side of the photovoltaic inverter 33. The AC side of the photovoltaic inverter 33 is connected to the power grid or an AC load. When there are two or more tandem photovoltaic units 20, the single output ports of the two or more tandem photovoltaic units 20 are connected to the DC combiner unit 32 in series and / or parallel. The DC combiner unit 32 has a built-in protection circuit. The central controller 31 is communicatively connected to the power controller 10 in the tandem photovoltaic unit 20 and the photovoltaic inverter 33, respectively, for realizing the coordinated control and status monitoring of the photovoltaic power generation system 30.

[0035] like Figure 6As shown, one embodiment of the present invention relates to a photovoltaic power generation system control method, including the following steps: System initialization: Establishing the DC bus voltage, acquiring the real-time voltage of the total output terminal of the battery layer not connected to the input terminal of the DC-DC converter 104 through the power intelligent controller 10 in the tandem photovoltaic unit 20, and setting the initial output voltage matching value; Synchronous real-time control: Real-time acquisition of the voltage and current of the total output terminal of the battery layer connected to the input terminal of the DC-DC converter 104, executing the MPPT algorithm, controlling the power intelligent controller 10 to make the battery layer connected to one path of the DC-DC converter 104 work at the maximum power point; using the other path of the battery layer... The real-time output voltage of the total output terminal of the layer is used as the target value. The output voltage of the DC-DC converter 104 is dynamically adjusted to ensure that the output voltage of the DC-DC converter 104 is consistent with the total output voltage of the other battery layer in real time, achieving parallel output without circulating current. Collaborative power optimization control: Based on system operating data, the MPPT tracking parameters and / or DC bus voltage are adjusted to ensure that the parallel tandem photovoltaic unit 20 operates at the global maximum power point. Fault protection and emergency handling steps: The system operating status is monitored in real time. When a fault occurs, the power conversion circuit of the faulty unit is shut down and the fault is isolated, an alarm is triggered, and automatic restart is waited for. The MPPT algorithm is a composite algorithm combining the incremental conductance method under normal operating conditions and the variable step size disturbance observation method under irradiation change conditions. The real-time voltage matching control adopts closed-loop PI regulation, using the total output voltage of the battery layer not connected to the input terminal of the DC-DC converter 104 as the reference value and the real-time output voltage of the power intelligent controller 10 as the feedback value, dynamically correcting the PWM duty cycle to ensure that the voltage deviation is less than a preset threshold.

[0036] Taking the perovskite-crystalline silicon tandem photovoltaic power generation system 30 as an example, the power controller 10 is connected to the crystalline silicon cell layer and uses a boost DC-DC converter to boost the total output voltage of the crystalline silicon cell layer to a voltage level that matches the total output voltage of the perovskite cell layer. The specific control method of the photovoltaic power generation system 30 is as follows: System initialization: After the system is powered on, the central controller 31 performs a self-test, checks the communication links of the entire system, and confirms that all boost-type power controllers 10 and photovoltaic inverters 33 are in normal condition. The photovoltaic inverter 33 first establishes the DC bus voltage (initial value set to 52V×12=624V). Each boost-type power controller 10 collects the real-time output voltage U_pv of the perovskite cell layer through the sampling module 15, sets the initial output voltage matching value, and completes the initialization.

[0037] Synchronous Real-Time Control: After system initialization, the boost-type power controller 10 synchronously executes MPPT tracking and real-time voltage matching parallel control of the crystalline silicon cell layer. These two controls operate in real-time in parallel, without any sequential order. MPPT tracking of the crystalline silicon cell layer: The power controller 10 samples the output voltage U_si and current I_si of the crystalline silicon layer at a frequency of 10kHz. Under normal operating conditions, the incremental conductance method is used to calculate the direction of power change, and the PWM duty cycle is adjusted to stabilize U_si at the maximum power point voltage (rated 36V). When a sudden irradiance change is detected (e.g., dP / dt > 20% / s), it automatically switches to the variable step size disturbance observation method to quickly track the new maximum voltage. High power point, avoiding power loss; real-time voltage matching parallel control: The power controller 10 samples the perovskite layer output voltage U_pv in real time at a frequency of 20kHz. Using U_pv as a reference value and the real-time output voltage U_out of the power controller 10 as a feedback value, it performs closed-loop PI regulation. The calculated duty cycle correction is superimposed on the base duty cycle determined by the MPPT to dynamically correct the total PWM duty cycle, so that U_out follows U_pv in real time, and the voltage deviation is controlled within 0.5%. When the perovskite layer voltage fluctuates due to temperature and light changes, the power controller 10 completes the adjustment within 100μs, completely avoiding circulating current in the parallel circuit.

[0038] Collaborative power optimization control: The central controller 31 collects real-time data on the U_pv, U_si, I_si, U_out, output current, ambient irradiance, module temperature, and other operating conditions of all tandem photovoltaic units 20. Under low light conditions (irradiance <300W / m²), the central controller 31 sends instructions to each power controller 10 to reduce the MPPT step size to half that under normal conditions, increase the sampling frequency to 20kHz, and optimize the PI regulator parameters to improve the MPPT tracking accuracy under low light conditions.

[0039] Fault Protection and Emergency Handling: During system operation, the fault protection module 13 monitors fault states such as input overcurrent, output overvoltage, overtemperature, short circuit, and reverse current in real time. When a power controller 10 detects a fault, it immediately triggers a protection action. The main control module 11 turns off the power switch Q and simultaneously turns on the reverse current blocking unit to cut off the output circuit, isolating the faulty unit from the parallel circuit to avoid affecting the normal operation of the entire system. At the same time, it sends a fault code to the central controller 31 through the communication module 18, and the central controller 31 uploads the alarm information to the operation and maintenance platform. After the fault is cleared, the power controller 10 performs an automatic restart self-test and resumes normal operation after confirming that there are no abnormalities.

[0040] The power controller 10, the tandem photovoltaic unit 20, and the photovoltaic power generation system 30 provided by this invention will be further described in conjunction with practical application scenarios.

[0041] Application Example 1 In this application example, the photovoltaic power generation system 30 is a perovskite-crystalline silicon photovoltaic system, adapted to a standard 182mm×182mm four-terminal tandem photovoltaic unit 20. A single tandem photovoltaic unit 20 includes, from top to bottom, a perovskite cell layer, a transparent insulating buffer layer, a crystalline silicon cell layer, and a boost-type power controller 10. The perovskite cell layer is the top cell of the four-terminal tandem battery, consisting of 15 perovskite sub-cells connected in series, with a maximum power point (MPP) voltage of approximately 52V and an open-circuit voltage of approximately 58V. The crystalline silicon cell layer is the bottom cell of the four-terminal tandem battery, consisting of 60 crystalline silicon sub-cells connected in series, with an MPP voltage of approximately 36V and an open-circuit voltage of approximately 42V. The total output voltage of the perovskite cell layer is always higher than that of the crystalline silicon cell layer. The total output terminal of the crystalline silicon solar cell layer is connected to the input terminal of the DC-DC converter 104 in the boost-type power controller 10. The output terminal of the DC-DC converter 104 is connected in parallel with the total output terminal of the perovskite solar cell layer, forming a single output port of the tandem photovoltaic unit 20. The rated operating voltage of the port is approximately 52V. Figure 3 As shown, the boost-type power controller 10 adopts a Boost topology and preferentially uses a single-stage non-isolated architecture as the implementation scheme. Specifically, it includes: an input filter module 16, which is a π-type EMI filter circuit containing an X capacitor and a common-mode inductor, used to suppress conducted interference; a power conversion module 12, which includes a power inductor L=100μH, a power switch Q, which is an N-channel superjunction MOSFET with a withstand voltage of 100V and an on-resistance of 15mΩ, and a freewheeling diode D, which is a silicon carbide Schottky diode with a withstand voltage of 150V and a current capability of 30A; an output filter module 17, which is an electrolytic capacitor + MLCC combined filter circuit, used to reduce output voltage ripple; a sampling module 15, which is a resistor voltage divider sampling circuit + Hall current sensor, used to collect input and output voltage and inductor current; a main control module 11, which is a 32-bit MCU with a built-in 12-bit ADC and complementary PWM output channels; a drive module 14, which is an isolated drive chip, used to improve the drive capability of the power switch; a communication module 18, which is an RS485 / PLC power line communication module; and a fault protection module 13.

[0042] The main control module 11 synchronously executes two core controls: First, it executes the MPPT algorithm, which uses the sampling module 15 to collect the total output voltage U_si and current I_si of the crystalline silicon cell layer in real time, calculates the real-time output power, and uses the incremental conductance method to adjust the PWM duty cycle D=1-U_si / U_out, so that the crystalline silicon cell layer can work stably at the maximum power point (rated 36V); Second, it executes real-time voltage matching control, which uses the sampling module 15 to collect the total output voltage U_pv (rated 52V) of the perovskite cell layer in real time, uses U_pv as the reference target value, and uses the actual output voltage U_out of the DC-DC converter 104 as the feedback value to perform PI closed-loop regulation, dynamically corrects the PWM duty cycle, so that U_out stably follows U_pv, with a voltage deviation of less than ±0.5% and a dynamic response time ≤100μs, avoiding circulating current in the parallel circuit.

[0043] In this application example, the switching frequency of the DC-DC converter 104 is set to 50kHz, the rated power is 650W, the measured conversion efficiency is ≥98.5%, and the MPPT tracking accuracy is ≥99.5%. The single-output ports of the 12 aforementioned tandem photovoltaic units 20 are connected in series to the DC combiner unit 32. The total rated voltage of the DC bus is approximately 624V, which is then inverted into industrial frequency AC power by the photovoltaic inverter 33 and connected to the power grid. The central controller 31 is integrated inside the photovoltaic inverter 33 and communicates with each boost-type power controller 10 via an RS485 bus to achieve data acquisition, coordinated control, and fault monitoring for the entire system.

[0044] Application Example 2 This application example shares the same core architecture as Application Example 1, the difference being that the perovskite cell layer voltage is 150-200V, while the crystalline silicon cell layer voltage is 30-50V, resulting in a relatively high voltage difference between the two. The perovskite cell layer consists of 60 perovskite sub-cells connected in series, with an MPP voltage of approximately 192V and an open-circuit voltage of approximately 210V; the crystalline silicon cell layer also consists of 60 crystalline silicon sub-cells connected in series, with an MPP voltage of approximately 36V. The input-output voltage ratio is approximately 5.33, requiring the boost-type power controller 10 to operate under high duty cycle conditions (rated duty cycle D = 1 - 36 / 192 ≈ 0.81).

[0045] To address the switching stress and efficiency losses caused by high duty cycles and high boost ratios, this application example features a targeted optimization design for the boost-type power controller 10: the boost inductor uses an iron-silicon-aluminum magnetic core with an inductance of 150μH and a saturation current of 60A, reducing inductance attenuation under DC bias and suppressing current ripple; the power switching transistor is a gallium nitride enhancement-type HEMT with a withstand voltage of 300V and an on-resistance of 30mΩ, significantly reducing switching losses at high switching frequencies; the freewheeling diode is a 600V silicon carbide Schottky diode with near-zero reverse recovery charge, effectively suppressing reverse recovery spikes and losses at high duty cycles; Control strategy optimization: Add duty cycle feedforward control, preset the initial duty cycle D_ref = 1-U_si / U_pv according to the input voltage U_si and the target output voltage U_pv, and then fine-tune it through the PI regulator to significantly improve the dynamic response speed; at the same time, add an inductor current peak limiting loop to prevent current overshoot during startup and dynamic operation. Switching frequency optimization: The rated switching frequency has been reduced to 40kHz, taking into account switching losses and the size of inductors and capacitors.

[0046] In this application example, the boost-type power controller 10 still adopts a single-stage non-isolated Boost architecture. The measured data are as follows: under the conditions of 36V input, 192V output, and 600W rated power, the peak conversion efficiency is ≥96.2%, the output voltage ripple is ≤1.5%, the MPPT tracking accuracy is ≥99.5%, and the voltage matching dynamic response time is ≤200μs, which fully meets the stable operation requirements of high differential stacked modules.

[0047] As can be seen from the above application examples, the Boost circuit provided in this invention has a simple structure, few components, and easy-to-implement control logic. It can cover a wide boost ratio range of 1.2 to 8 times, adapt to the multi-scenario stacked component requirements from low voltage drop (30V→50V) to high voltage drop (30V→200V), and can achieve a peak conversion efficiency of over 98.5% in low voltage drop scenarios and still maintain an efficiency of over 96% in high voltage drop scenarios.

[0048] Application Example 3 This application example shares the same core architecture as Application Example 1, with the difference being that the rated power of a single tandem photovoltaic unit 20 exceeds 700W, and the power controller 10 employs two or more Boost DC-DC converters 104 operating in parallel. The inputs of all Boost DC-DC converters 104 are connected in parallel and then uniformly connected to the total output of the crystalline silicon solar cell layer. Similarly, the outputs of all DC-DC converters 104 are connected in parallel and then uniformly connected to the total output of the perovskite solar cell layer. Current sharing control is achieved among the DC-DC converters 104 via a current sharing bus (analog current sharing or digital communication current sharing). The main control module 11 coordinates the PWM carrier phase of each DC-DC converter 104. When two converters are connected in parallel, a 180° staggered parallel control is used; when multiple converters are connected in parallel, uniform phase-shift control is used, significantly reducing input and output current ripple and the size of filtering devices. Without altering the core design of the single power controller 10, flexible power level expansion is achieved, adapting to high-power tandem photovoltaic unit 20 application scenarios.

[0049] Application Example 4 In this application example, the photovoltaic power generation system 30 is a perovskite-crystalline silicon photovoltaic system, suitable for low-dropout scenarios where the voltage of the perovskite cell layer is higher than that of the crystalline silicon cell layer. A single perovskite-crystalline silicon tandem photovoltaic unit 20 includes, from top to bottom, a perovskite cell layer, a transparent insulating buffer layer, a crystalline silicon cell layer, and a step-down power controller 10. The perovskite cell layer is the top cell of the four-terminal tandem photovoltaic system, composed of 30 perovskite sub-cells connected in series, with a maximum power point (MPP) voltage of approximately 110V and an open-circuit voltage of approximately 120V. The crystalline silicon cell layer is the bottom cell of the four-terminal tandem photovoltaic system, composed of 72 crystalline silicon sub-cells connected in series, with an MPP voltage of approximately 50V and an open-circuit voltage of approximately 58V. The total output voltage of the perovskite cell layer is always higher than that of the crystalline silicon cell layer.

[0050] The total output terminal of the perovskite solar cell layer is connected to the input terminal of the DC-DC converter 104 in the step-down power controller 10. The output terminal of the step-down DC-DC converter 104 is connected in parallel with the total output terminal of the crystalline silicon solar cell layer to form a single output port of the stacked photovoltaic unit 20. The rated operating voltage of the port is about 50V.

[0051] like Figure 4 As shown, the buck-type power controller 10 adopts a Buck topology and selects a single-stage non-isolated architecture as the preferred implementation scheme. Specifically, it includes: an input filter module 16, which is a π-type EMI filter circuit; a power conversion module 12, which includes a power switch Q, which is an N-channel superjunction MOSFET with a withstand voltage of 200V and an on-resistance of 15mΩ; a freewheeling diode D, which is a silicon carbide Schottky diode with a withstand voltage of 200V and a current capability of 20A; a buck inductor L=100μH; an output filter module 17, which is a combination filter circuit of electrolytic capacitor + MLCC; a sampling module 15, which is a resistor voltage divider sampling circuit + Hall current sensor; a main control module 11, which is a 32-bit MCU; a drive module 14, which is an isolated drive chip; a communication module 18, which is an RS485 communication module; and a fault protection module 13.

[0052] The main control module 11 synchronously executes two core controls: First, it executes the MPPT algorithm, which uses the sampling module 15 to collect the output voltage V_pv and current I_pv of the perovskite solar cell layer in real time, calculates the real-time output power, and uses the incremental conductance method to adjust the PWM duty cycle D so that the perovskite solar cell layer can work stably at the maximum power point (rated 110V); Second, it executes real-time voltage matching control, which uses the sampling module 15 to collect the output voltage V_si (rated 50V) of the crystalline silicon solar cell layer in real time, uses V_si as the reference target value, and uses the actual output voltage V_out of the DC-DC converter 104 as the feedback value to perform PI closed-loop regulation, dynamically corrects the PWM duty cycle, so that V_out stably follows V_si, with a voltage deviation of less than ±0.5% and a dynamic response time ≤100μs.

[0053] In this application example, the rated duty cycle of the DC-DC converter 104 is D=50 / 110≈0.455, the switching frequency is set to 80kHz, the rated power is 500W, the measured conversion efficiency is ≥98.5%, and the MPPT tracking accuracy is ≥99.5%. The single-output ports of the 12 aforementioned tandem photovoltaic units 20 are connected in series to the DC combiner unit 32. The total rated voltage of the DC bus is approximately 600V, which is then inverted into industrial frequency AC power by the photovoltaic inverter 33 and connected to the power grid. The central controller 31 is integrated inside the photovoltaic inverter 33 and communicates with each step-down power controller 10 via an RS485 bus.

[0054] Application Example 5 This application example shares the same core architecture as Application Example 4, the difference being that the perovskite cell layer voltage is approximately 200V, while the crystalline silicon cell layer voltage is approximately 20V, resulting in a relatively high voltage difference between the two. The perovskite cell layer consists of 60 perovskite sub-cells connected in series, with an MPP voltage of approximately 200V and an open-circuit voltage of approximately 220V. The crystalline silicon cell layer is primarily composed of a small number of crystalline silicon sub-cells connected in parallel, with an MPP voltage of approximately 20V. The step-down ratio is approximately 10, and the step-down power controller 10 needs to operate under low duty cycle conditions (rated duty cycle D = 20 / 200 = 0.1).

[0055] To address the switching stress and efficiency losses caused by high buck ratios, this application example features a targeted optimization design for the buck-type power controller 10: the buck inductor uses an iron-silicon-aluminum magnetic core with an inductance of 220μH and a saturation current of 30A, reducing inductance attenuation under DC bias and suppressing current ripple; the power switch is a gallium nitride enhancement-type HEMT with a withstand voltage of 300V and an on-resistance of 25mΩ, significantly reducing switching losses; the freewheeling diode is a 300V silicon carbide Schottky diode with near-zero reverse recovery charge, effectively suppressing switching losses. Control strategy optimization: Add duty cycle feedforward control, preset the initial duty cycle D_ref = V_si / V_pv according to the input voltage V_pv and the target output voltage V_si, and then fine-tune it through the PI regulator to significantly improve the dynamic response speed; at the same time, add an inductor current peak limiting loop to prevent current overshoot during startup and dynamic operation. Switching frequency optimization: The rated switching frequency has been reduced to 40kHz, taking into account switching losses and the size of inductors and capacitors.

[0056] In this application example, the step-down power controller 10 still adopts a single-stage non-isolated Buck architecture. The measured data are as follows: under the conditions of 200V input, 20V output, and 400W rated power, the peak conversion efficiency is ≥95.5%, the output voltage ripple is ≤1.5%, the MPPT tracking accuracy is ≥99.5%, and the voltage matching dynamic response time is ≤200μs.

[0057] The tandem photovoltaic unit and its power controller, photovoltaic power generation system and its control method provided by this invention, wherein the power controller performs the MPPT algorithm on a single battery layer through a DC-DC converter and converts its total output voltage to match the total output voltage of another battery layer, and connects them in parallel to form a single output port, abandoning the existing sub-cell level power optimization scheme, and adopting a unified boost optimization of the entire sub-cell string, significantly reducing the number of power optimizers used compared to the existing scheme, which can effectively reduce system cost and packaging integration difficulty; the structure is simplified and the control is simple, which can not only solve the problem of voltage mismatch and difficulty in parallel connection of 4T architecture tandem photovoltaic units in the prior art, but also be compatible with existing photovoltaic systems through a single output port, reducing system cost, and effectively improving the feasibility of mass production and the reliability of operation of tandem photovoltaic units. In particular, the DC-DC converter, through its main control module, adjusts the PWM duty cycle of the power switching transistors in the power conversion module to simultaneously achieve boost or buck conversion, maximum power point tracking, and total output voltage matching control with the battery layer connected to the DC-DC converter input. This ensures precise voltage matching between the two battery layers. Combined with real-time closed-loop voltage tracking control, this enables direct, non-circulating current parallel connection of the two outputs, avoiding power loss caused by voltage mismatch. Furthermore, the tandem photovoltaic unit's battery layer, connected via a power controller, outputs a single DC power supply, which can be directly connected to existing mainstream single-input photovoltaic inverters without the need for customized dual-MPPT inverters. This ensures full compatibility with existing photovoltaic power plant architectures, equipment, and construction specifications, significantly lowering the barrier to large-scale application of tandem photovoltaic units. By implementing system initialization, synchronous real-time control, and collaborative power optimization control in the photovoltaic power generation system control method, the core advantages of the four-terminal stacked photovoltaic unit are retained while achieving single-path output. The single-path battery layer achieves independent MPPT through a DC-DC converter, and the other battery layer achieves MPPT through a photovoltaic inverter. It can adapt to complex outdoor conditions such as spectral shift, temperature fluctuation, and partial shading, effectively improving the power generation revenue of the photovoltaic power generation system.

[0058] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be defined by the claims.

Claims

1. A power intelligent controller, characterized in that, For a tandem photovoltaic unit (20), the tandem photovoltaic unit (20) includes a first battery layer (21) and a second battery layer (22); the power controller (10) includes a first input port (101), a second input port (102) and an output port (103); the first input port (101) is connected to the total output terminal of the first battery layer (21), and the second input port (102) is connected to the total output terminal of the second battery layer (22); the power controller (10) also includes at least one DC-DC converter (104). The DC-DC converter (104) is located on the power path between the first input port (101) or the second input port (102) and the output port (103). The DC-DC converter (104) performs the MPPT algorithm on the connected battery layer and performs DC voltage conversion, converting the total output voltage of the connected battery layer to match the total output voltage of the other battery layer. The output terminal of the DC-DC converter (104) is connected in parallel with the total output terminal of the other battery layer to form a single output port.

2. The power controller according to claim 1, characterized in that, The DC-DC converter (104) is a boost DC-DC converter, which is connected to one of the battery layers with a lower total output voltage, and boosts the total output voltage of the battery layer to match the total output voltage of the other battery layer with a higher voltage.

3. The power controller according to claim 1, characterized in that, The DC-DC converter (104) is a step-down DC-DC converter, which is connected to one of the battery layers with a higher total output voltage, and steps down the total output voltage of the battery layer to match the total output voltage of the other battery layer with a lower voltage.

4. The power controller according to claim 1, characterized in that, There are multiple DC-DC converters. The input terminals of the multiple DC-DC converters (104) are connected in parallel and then connected to the total output terminal of one of the first battery layer (21) or the second battery layer (22). The output terminals of the multiple DC-DC converters (104) are connected in parallel and then connected to the total output terminal of another battery layer.

5. The power controller according to claim 1, characterized in that, The DC-DC converter includes a main control module (11) and a power conversion module (12). The main control module (11) adjusts the PWM duty cycle of the power switching transistor in the power conversion module (12) to synchronously realize the boost or buck conversion, maximum power point tracking and total output voltage matching control of the battery layer connected to the input terminal of the DC-DC converter (104).

6. The power controller according to claim 5, characterized in that, The DC-DC converter (104) is also integrated with a fault protection module (13), which includes at least one of the following: input reverse connection protection, input overcurrent protection, output overvoltage protection, overtemperature protection, short circuit shutdown and reverse current blocking unit.

7. A multilayer photovoltaic unit, characterized in that, The system includes a first battery layer (21) and a second battery layer (22) stacked together, and a power controller (10) as described in any one of claims 1-6. The DC-DC converter (104) of the power controller (10) performs the MPPT algorithm and DC voltage conversion on the connected battery layer to convert the total output voltage of the connected battery layer to match the total output voltage of the other battery layer. The output terminal of the DC-DC converter (104) is connected in parallel with the total output terminal of the other battery layer to form a single output port of the stacked photovoltaic unit (20).

8. The tandem photovoltaic unit according to claim 7, characterized in that, The first battery layer (21) is a crystalline silicon battery layer, which is formed by connecting multiple crystalline silicon sub-cells in series and / or in parallel, and is provided with a total output terminal of the crystalline silicon battery layer; the second battery layer (22) is a perovskite battery layer, which is formed by connecting multiple perovskite sub-cells in series and / or in parallel, and is provided with a total output terminal of the perovskite battery layer.

9. The tandem photovoltaic unit according to claim 8, characterized in that, The total output voltage of the perovskite cell layer is higher than the total output voltage of the crystalline silicon cell layer. The power controller (10) has a built-in boost DC-DC converter. The input terminal of the boost DC-DC converter is electrically connected to the total output terminal of the crystalline silicon cell layer. The boost topology circuit is used to boost the total output voltage of the crystalline silicon cell layer to a voltage level that matches the total output voltage of the perovskite cell layer.

10. The tandem photovoltaic unit according to claim 8, characterized in that, The total output voltage of the perovskite cell layer is higher than that of the crystalline silicon cell layer. The power controller (10) has a built-in step-down DC-DC converter. The input terminal of the step-down DC-DC converter is electrically connected to the total output terminal of the perovskite cell layer. The Buck step-down topology circuit is used to step down the total output voltage of the perovskite cell layer to a voltage level that matches the total output voltage of the crystalline silicon cell layer.

11. A photovoltaic power generation system, characterized in that, It includes at least one tandem photovoltaic unit (20) as described in any one of claims 7-10, a DC combiner unit (32) and a photovoltaic inverter (33); the single output ports of the tandem photovoltaic unit (20) are all connected to the DC combiner unit (32), the output terminal of the DC combiner unit (32) is electrically connected to the DC side of the photovoltaic inverter (33), and the AC side of the photovoltaic inverter (33) is connected to the power grid or AC load.

12. The photovoltaic power generation system according to claim 11, characterized in that, Two or more of the stacked photovoltaic units (20) have their single output ports connected to the DC combiner unit (32) in series and / or parallel, and the DC combiner unit (32) has a built-in protection circuit.

13. The photovoltaic power generation system according to claim 11 or 12, characterized in that, It also includes a central controller (31), which is communicatively connected to the power controller (10) in the stacked photovoltaic unit (20) and the photovoltaic inverter (33) to realize the coordinated control and status monitoring of the photovoltaic power generation system (30).

14. A control method for a photovoltaic power generation system, characterized in that, Includes the following steps: System initialization: Establish DC bus voltage, collect the real-time voltage of the total output terminal of the battery layer that is not connected to the input terminal of the DC-DC converter (104) through the power intelligent controller (10) in the stacked photovoltaic unit (20), and set the initial output voltage matching value; Synchronous real-time control: Real-time acquisition of the voltage and current of the total output terminal of the battery layer connected to the input terminal of the DC-DC converter (104), execution of the MPPT algorithm, and control of the power controller (10) to make the battery layer connected to one channel work at the maximum power point; taking the real-time output voltage of the total output terminal of the other battery layer as the target value, dynamically adjusting the output voltage of the DC-DC converter (104) so ​​that the output voltage of the DC-DC converter (104) is kept consistent with the total output voltage of the other battery layer in real time, and realizing parallel output without circulating current; Collaborative power optimization control: Based on system operating data, adjust MPPT tracking parameters and / or DC bus voltage to make the parallel tandem photovoltaic units (20) operate at the global maximum power point.

15. The photovoltaic power generation system control method according to claim 14, characterized in that, It also includes fault protection and emergency handling procedures, real-time monitoring of system operation status, and when a fault occurs, shutting down the power conversion circuit of the faulty unit and isolating the fault, triggering an alarm and waiting for automatic restart.

16. The photovoltaic power generation system control method according to claim 14, characterized in that, The MPPT algorithm is a composite algorithm combining the incremental conductance method under normal operating conditions and the variable step size disturbance observation method under sudden irradiation conditions. The real-time voltage matching control adopts closed-loop PI regulation, taking the total output voltage of the battery layer not connected to the input terminal of the DC-DC converter (104) as the reference value and the real-time output voltage of the power controller (10) as the feedback value, and dynamically corrects the PWM duty cycle so that the voltage deviation is less than the preset threshold.

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