Photovoltaic power generation system, photovoltaic optimizer and control method thereof

Abstract

The invention discloses a photovoltaic power generation system, a photovoltaic optimizer and a control method thereof. The photovoltaic optimizer comprises a first photovoltaic optimization module, a second photovoltaic optimization module, a first photovoltaic module, a second photovoltaic module, a first control module, a second control module and a communication module. The first photovoltaic optimization module is used for being connected with a first photovoltaic module; the second photovoltaic optimization module is used for being connected with a second photovoltaic module, and the first output end of the second photovoltaic optimization module is connected with the second output end of the first photovoltaic module; the first control module is used for controlling the first photovoltaic optimization module to optimize the output power of the first photovoltaic module; the second control module is used for controlling the second photovoltaic optimization module to optimize the output power of the second photovoltaic module; the communication module is used for transmitting communication information between the first control module and the second control module. According to the invention, the plurality of photovoltaic modules can be independently controlled, so that the power generation efficiency of the system can be improved.

Description

Technical Field

[0001] This application relates to the field of electronic technology, specifically to a photovoltaic power generation system, a photovoltaic optimizer, and a control method thereof. Background Technology

[0002] In solar photovoltaic (PV) power generation systems, the output power of solar modules is affected by various factors, such as sunlight intensity, temperature, and shading. In traditional PV systems, multiple solar modules are typically connected in series or parallel. When the output power of one module decreases due to shading or other factors, it affects the output power of the entire series or parallel branch, reducing the system's power generation efficiency. To improve the efficiency of PV power generation systems, power optimizers have emerged.

[0003] While current power optimizers can improve the power generation efficiency of modules to some extent, their cost is high. Adding an optimizer to each module significantly increases the overall cost of the power plant. To reduce the cost of optimizers per module, one-to-two or one-to-many optimizers have emerged. Existing one-to-two optimizers connect two modules in series to the power optimizer. When the two modules operate under different conditions, unified optimization cannot ensure that each module operates at its maximum power point, thus limiting the power generation efficiency of the entire system.

[0004] Therefore, the technology still needs to be improved and enhanced. Summary of the Invention

[0005] This application provides a photovoltaic power generation system, a photovoltaic optimizer, and a control method thereof, which can independently control multiple photovoltaic modules to improve the power generation efficiency of the system.

[0006] This application provides a photovoltaic optimizer, the photovoltaic optimizer comprising: A first photovoltaic optimization module, wherein a first input terminal and a second input terminal of the first photovoltaic optimization module are used to connect to a first photovoltaic module, and a first output terminal of the first photovoltaic optimization module is used to connect to a load; The second photovoltaic optimization module has a first input terminal and a second input terminal for connecting to the second photovoltaic module, and a first output terminal for connecting to the second output terminal of the first photovoltaic module; the second output terminal of the second photovoltaic optimization module is used to connect to the load. The first control module is connected to the control terminal of the first photovoltaic optimization module. The first control module is used to control the first photovoltaic optimization module to optimize the output power of the first photovoltaic module. The second control module is connected to the control terminal of the second photovoltaic optimization module and the first control module respectively; the second control module is used to control the second photovoltaic optimization module to optimize the output power of the second photovoltaic module. The communication module is connected to both the first control module and the second control module, and is used to transmit communication information between the first control module and the second control module.

[0007] In some embodiments of the photovoltaic optimizer, the first control module is further configured to detect the first output voltage, the first input current and the first operating temperature of the first photovoltaic optimization module, and when the first input voltage, the first input current and the first operating temperature all meet the preset conditions, control the first photovoltaic optimization module to perform maximum power point tracking. The second control module is also used to detect the second output voltage, second input current and second operating temperature of the second photovoltaic optimization module, and when the second output voltage, second input current and second operating temperature all meet the preset conditions, it controls the second photovoltaic optimization module to perform maximum power point tracking.

[0008] In some embodiments of the photovoltaic optimizer, the first control module is further configured to detect the first output voltage of the first photovoltaic optimizer when the first output power of the first photovoltaic optimizer is the first target output power, and output the first output voltage to the second control module through the communication module; The second control module is also used to detect the second output voltage of the second photovoltaic optimization module when the second output power of the second photovoltaic optimization module is the second target output power, and output the second output voltage to the first control module through the communication module. The first control module is also used to control the first photovoltaic optimization module to stop working when the total voltage of the first output voltage and the second output voltage does not meet the preset voltage condition; the second control module is also used to control the second photovoltaic optimization module to stop working when the total output voltage of the first output voltage and the second output voltage does not meet the preset voltage condition.

[0009] In some embodiments of the photovoltaic optimizer, the first control module is further configured to detect the first output current of the first photovoltaic optimizer when the first output power of the first photovoltaic optimizer is the first target output power, and output the first output current to the second control module through the communication module. The second control module is also used to detect the second output current of the second photovoltaic optimization module when the second output power of the second photovoltaic optimization module is the second target output power, and to output the second output current to the first control module through the communication module. The first control module is also used to control the first photovoltaic optimization module to stop working when the total current of the first output current and the second output current does not meet the preset current condition; the second control module is also used to control the second photovoltaic optimization module to stop working when the total output current of the first output current and the second output current does not meet the preset current condition.

[0010] In some embodiments of the photovoltaic optimizer, the first control module is further configured to output the first output power to the second control module via the communication module when the first output power of the first photovoltaic optimizer is the first target output power; the second control module is further configured to output the second output power to the first control module via the communication module when the second output power of the second photovoltaic optimizer is the second target output power. The first control module is also used to control the first photovoltaic optimization module to stop working when the total power of the first output power and the second output power does not meet the preset power condition; the second control module is also used to control the second photovoltaic optimization module to stop working when the total output power of the first output power and the second output power does not meet the preset power condition.

[0011] In some embodiments of the photovoltaic optimizer, the first control module is further configured to detect the first output voltage of the first photovoltaic optimizer when the first output power of the first photovoltaic optimizer is the first target output power, and control the first photovoltaic optimizer to stop working when the first output voltage does not meet the second preset voltage condition.

[0012] In some embodiments of the photovoltaic optimizer, the first photovoltaic optimization module includes a first switch, a second switch, a first capacitor, a first inductor, and a first capacitor. The first terminal of the first switching transistor and the second terminal of the second switching transistor are connected to the first control module. The second terminal of the first switching transistor is connected to the first input terminal of the first photovoltaic optimization module. The third terminal of the first switching transistor is connected to the second terminal of the first inductor and the second switching transistor. The third terminal of the second switching transistor is connected to the second output terminal of the first photovoltaic optimization module. One end of the first inductor is connected to the third terminal of the first switching transistor. The other end of the first inductor is connected to the first output terminal of the first photovoltaic optimization module. One end of the first capacitor is connected to the first terminal of the first switching transistor. The other end of the first capacitor is connected to the third terminal of the second switching transistor. One end of the second capacitor is connected to the other end of the first inductor. The other end of the second capacitor is connected to the third terminal of the second switching transistor.

[0013] In some embodiments of the photovoltaic optimizer, the second photovoltaic optimization module includes a third switch, a fourth switch, a third capacitor, a second inductor, and a fourth capacitor; The first terminal of the third switch and the second terminal of the fourth switch are connected to the second control module. The second terminal of the third switch is connected to the first input terminal of the second photovoltaic optimization module. The third terminal of the third switch is connected to the second inductor and the second terminal of the fourth switch. The third terminal of the fourth switch is connected to the second output terminal of the second photovoltaic optimization module. One end of the second inductor is connected to the third terminal of the fourth switch. The other end of the second inductor is connected to the first output terminal of the second photovoltaic optimization module. One end of the third capacitor is connected to the first terminal of the third switch. The other end of the third capacitor is connected to the third terminal of the fourth switch. One end of the fourth capacitor is connected to the other end of the second inductor. The other end of the fourth capacitor is connected to the third terminal of the fourth switch.

[0014] This application also provides a control method for a photovoltaic optimizer, which is applied to the aforementioned photovoltaic optimizer; the control method includes: When the first output voltage, first input current, and first operating temperature of the first photovoltaic optimization module all meet the preset conditions, the first photovoltaic optimization module is controlled to perform maximum power point tracking; when the second output voltage, second input current, and second operating temperature all meet the preset conditions, the second photovoltaic optimization module is controlled to perform maximum power point tracking. When the first output power of the first photovoltaic optimization module is the first target output power and the second output power of the second photovoltaic optimization module is the second target output power, the total output voltage and total output power of the first photovoltaic optimization module and the second photovoltaic optimization module are detected. If the total output voltage does not meet the preset voltage condition or the total output power does not meet the preset power condition, then both the first photovoltaic optimization module and the second photovoltaic optimization module will stop working.

[0015] This application also provides a photovoltaic power generation system, which includes a first photovoltaic module, a second photovoltaic module, a load, and the aforementioned photovoltaic optimizer. The input terminal of the photovoltaic optimizer is connected to the first photovoltaic module and the second photovoltaic module, respectively, and the output terminal of the photovoltaic optimizer is connected to the load.

[0016] This application provides a photovoltaic power generation system, a photovoltaic optimizer, and a control method thereof. The photovoltaic optimizer includes a first photovoltaic optimization module, a second photovoltaic optimization module, a first photovoltaic module, a second photovoltaic module, a first control module, a second control module, and a communication module. The photovoltaic optimizer in this application sets up two corresponding control modules for the two photovoltaic optimization modules. Each photovoltaic optimization module is connected to its corresponding photovoltaic module, and each control module can independently control the operation of its corresponding photovoltaic optimization module. When two photovoltaic modules are simultaneously input, the first and second control modules, based on the communication module, consider the power output of the two photovoltaic modules and use an optimization algorithm to maximize the total output power. When only one photovoltaic module is input, it also ensures that the module outputs maximum power, thereby achieving power maximization under different input conditions and improving the reliability of the entire photovoltaic power generation system. Attached Figure Description

[0017] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0018] Figure 1 This is a first structural block diagram of a photovoltaic optimizer provided in an embodiment of this application.

[0019] Figure 2 This is a second structural block diagram of a photovoltaic optimizer provided in an embodiment of this application.

[0020] Figure 3 This is a third structural block diagram of the photovoltaic optimizer provided in the embodiments of this application.

[0021] Figure 4 This is a fourth structural block diagram of the photovoltaic optimizer provided in the embodiments of this application.

[0022] Figure 5 The circuit diagrams of the first photovoltaic optimization module and the second photovoltaic optimization module in the photovoltaic optimizer provided in the embodiments of this application are shown.

[0023] Figure 6 This is a schematic diagram of the working process of the photovoltaic optimizer provided in the embodiments of this application.

[0024] Figure 7 This is a schematic flowchart of the control method for a photovoltaic optimizer provided in an embodiment of this application.

[0025] Figure 8 This is a schematic diagram of the structure of the photovoltaic optimizer provided in the embodiments of this application. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Features thus defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0028] Please see Figure 1 This application provides a photovoltaic optimizer, which, as the main control component for improving the power generation efficiency of photovoltaic panels, primarily mitigates the impact of low power generation efficiency caused by factors such as shading and inconsistent photovoltaic orientation. Its core function is to use the maximum power point tracking (MPPT) algorithm to ensure that the photovoltaic panel maintains its current maximum power output even when shading occurs.

[0029] The photovoltaic optimizer in this embodiment includes a first photovoltaic optimization module 11, a second photovoltaic optimization module 12, a first control module 13, a second control module 14, and a communication module 15. The first input terminal and the second input terminal of the first photovoltaic optimization module 11 are used to connect to the first photovoltaic module 21, and the first output terminal of the first photovoltaic optimization module 11 is used to connect to the load 31. The first input terminal and the second input terminal of the second photovoltaic optimization module 12 are used to connect to the second photovoltaic module 22, and the first output terminal of the second photovoltaic optimization module 12 is connected to the second output terminal of the first photovoltaic module 21. The second output terminal of the second photovoltaic optimization module 12 is used to connect to the load 31. The first control module 13 is connected to the control terminal of the first photovoltaic optimization module 11, and the second control module 14 is connected to both the control terminal of the second photovoltaic optimization module 12 and the first control module 13. The communication module 15 is connected to both the first control module 13 and the second control module 14.

[0030] The first photovoltaic module 21 and the second photovoltaic module 22 include solar panels or photovoltaic panels, which convert solar energy into electrical energy. The loads 31 connected to the photovoltaic optimizer include off-grid system loads 31, grid-connected system loads 31, and hybrid system loads 31. The hybrid system loads 31 combine the characteristics of both off-grid and grid-connected systems. The off-grid system is self-contained and not connected to the public power grid; therefore, its loads 31 are completely independent. The off-grid system loads 31 include DC loads 31 (directly using the DC power output from the photovoltaic optimizer, requiring no inverter conversion, resulting in high efficiency) and AC loads 31 (used after DC power is converted to AC power by an inverter). Common DC loads 31 in the off-grid system include streetlights, lamps, mobile phones, laptops, DC fans, DC water pumps, etc., while AC loads 31 include refrigerators, air conditioners, televisions, small motors, and feed mills, etc. The grid-connected system is connected to the public power grid, and its loads 31 are shared by the power grid and the photovoltaic power generation system. The load 31 of the grid-connected system includes local load 31 and grid load 31. Local load 31 is the load 31 installed in the same location as the photovoltaic power generation system (such as a house or factory roof). The photovoltaic power generation system prioritizes meeting the electricity demand of local load 31. As for grid load 31, the excess electricity generated by the photovoltaic system is uploaded to the grid and incorporated into the vast grid network to supply other users anywhere on the network.

[0031] In the photovoltaic optimizer, the first control module 13 controls the first photovoltaic optimization module 11 to optimize the output power of the first photovoltaic module 21; the second control module 14 controls the second photovoltaic optimization module 12 to optimize the output power of the second photovoltaic module 22; and the communication module 15 transmits communication information between the first control module 13 and the second control module 14. This communication information includes the input current, voltage, and power, and the output current, voltage, and power of each photovoltaic optimization module. The control modules of each photovoltaic optimization module establish a communication connection through the communication module 15, which facilitates the synchronization of the working states of each photovoltaic optimization module. In this embodiment, the photovoltaic optimizer uses two photovoltaic optimization modules to connect to the photovoltaic modules, and each photovoltaic optimization module is connected to its own control module. The control module can independently control the photovoltaic optimization module, thereby achieving independent control of the photovoltaic modules, which is beneficial for each photovoltaic module to operate at its corresponding maximum power point.

[0032] It should be noted that this embodiment uses two photovoltaic optimization modules as an example for illustration. When two photovoltaic optimization modules are set in the photovoltaic optimizer, a one-to-two optimizer can be realized. The photovoltaic optimizer can also be set with three or more photovoltaic optimization modules. If multiple photovoltaic optimization modules are set in the photovoltaic optimizer, each photovoltaic optimization module is set with a corresponding control module. The output terminals of the photovoltaic optimization modules can be connected in series. One output terminal of the first photovoltaic optimization module in the series connection is used to connect to the load 31, and one output terminal of the last photovoltaic optimization module is also used to connect to the load 31. Each photovoltaic optimization module's input terminal can be connected to a photovoltaic module, thus realizing a one-to-many optimizer.

[0033] Please see Figure 2 In some embodiments, the photovoltaic optimizer is also provided with an auxiliary power supply 16, which is connected to the first control module 13 and the second control module 14 respectively. The auxiliary power supply 16 is used to provide power to the first control module 13 and the second control module 14 to ensure the normal operation of the first control module 13 and the second control module 14.

[0034] In some embodiments, the first control module 13 is further configured to detect the first input voltage, the first input current, and the first operating temperature of the first photovoltaic optimization module 11, and control the first photovoltaic optimization module 11 to perform maximum power point tracking when the first input voltage, the first input current, and the first operating temperature all meet preset conditions. The second control module 14 is further configured to detect the second output voltage, the second input current, and the second operating temperature of the second photovoltaic optimization module 12, and control the second photovoltaic optimization module 12 to perform maximum power point tracking when the second input voltage, the second input current, and the second operating temperature all meet preset conditions.

[0035] Specifically, the preset conditions are that the input voltage does not exceed a first threshold voltage, the input current does not exceed a first threshold current, and the operating temperature does not exceed a threshold temperature. For example, the first threshold voltage is 75V, the first threshold current is 22A, and the threshold temperature is 120℃. When the first input voltage of the first photovoltaic optimization module 11 does not exceed 75V, the first input current does not exceed 22A, and the first operating temperature does not exceed 120℃, it indicates that the first photovoltaic optimization module 11 is working normally, and then the first control module 13 controls the first photovoltaic optimization module 11 to perform maximum power point tracking. Similarly, when the second input voltage of the second photovoltaic optimization module 12 does not exceed 75V, the second input current does not exceed 22A, and the second operating temperature does not exceed 120℃, it indicates that the second photovoltaic optimization module 12 is working normally, and then the second control module 14 controls the second photovoltaic optimization module 12 to perform maximum power point tracking, thereby achieving independent control of each photovoltaic module.

[0036] In some embodiments, the first control module 13 is further configured to detect the first output voltage of the first photovoltaic optimization module 11 when the first output power of the first photovoltaic optimization module 11 is the first target output power, and output the first output voltage to the second control module 14 via the communication module 15. The first target output power can be the maximum power after the first photovoltaic optimization module 11 performs maximum power point tracking on the output power value of the first photovoltaic module 21, thereby ensuring the operating efficiency of the first photovoltaic module 21. Similarly, the second control module 14 is further configured to detect the second output voltage of the second photovoltaic optimization module 12 when the second output power of the second photovoltaic optimization module 12 is the second target output power, and output the second output voltage to the first control module 13 via the communication module 15. The second target output power can be the maximum power after the second photovoltaic optimization module 12 performs maximum power point tracking on the output power value of the second photovoltaic module 22, thereby ensuring the operating efficiency of the second photovoltaic module 22.

[0037] The first control module 13 is further configured to control the first photovoltaic optimization module 11 to stop working when the total voltage of the first output voltage and the second output voltage does not meet the first preset voltage condition; the second control module 14 is further configured to control the second photovoltaic optimization module 12 to stop working when the total output voltage of the first output voltage and the second output voltage does not meet the first preset voltage condition.

[0038] Specifically, when two photovoltaic (PV) modules are connected to the PV optimizer simultaneously, their respective control modules control the corresponding PV optimization modules to perform maximum power point tracking (MPPT). Once the output power of each module reaches its target output power, the output voltage of the PV optimization modules is detected. The first control module 13 acquires the first output voltage of the first PV optimization module 11, and the second control module 14 acquires the second output voltage of the second PV optimization module 12. The first control module 13 then transmits the respective output voltages via the communication module 15. The first control module 13 determines the total output voltage based on the first and second output voltages, and the second control module 14 also determines the total output voltage based on the first and second output voltages. A first preset voltage condition is that the total output voltage does not exceed a second threshold voltage, for example, 120V. If the total output voltage exceeds 120V, i.e., the total output voltage does not meet the first preset voltage condition, it indicates that the PV modules may be malfunctioning. In this case, the first control module 13 and the second control module 14 respectively control the first PV optimization module 11 and the second PV optimization module 12 to stop operating.

[0039] In some embodiments, the first control module 13 is further configured to detect the first output current of the first photovoltaic optimization module 11 when the first output power of the first photovoltaic optimization module 11 is the first target output power, and output the first output current to the second control module 14 through the communication module 15; the second control module 14 is further configured to detect the second output current of the second photovoltaic optimization module 12 when the second output power of the second photovoltaic optimization module 12 is the second target output power, and output the second output current to the first control module 13 through the communication module 15.

[0040] The first control module 13 is further configured to control the first photovoltaic optimization module 11 to stop working when the total current of the first output current and the second output current does not meet a preset current condition; the second control module 14 is further configured to control the second photovoltaic optimization module 12 to stop working when the total output current of the first output current and the second output current does not meet the preset current condition. For example, the preset current condition is that the output current is not greater than a second threshold current, such as 22A. If the total output current of the first photovoltaic optimization module 11 exceeds 22A, it indicates that the total output current does not meet the preset current condition, which suggests that the photovoltaic module may be malfunctioning. To improve safety, the first photovoltaic optimization module 11 and the second photovoltaic optimization module 12 are then controlled to stop working. The second threshold current can be set according to actual conditions; in this embodiment, this current value is not limited.

[0041] In some embodiments, the first control module 13 is further configured to output the first output power to the second control module 14 via the communication module 15 when the first output power of the first photovoltaic optimization module 11 is the first target output power; the second control module 14 is further configured to output the second output power to the first control module 13 via the communication module 15 when the second output power of the second photovoltaic optimization module 12 is the second target output power. The first control module 13 is further configured to control the first photovoltaic optimization module 11 to stop working when the total power of the first output power and the second output power does not meet a preset power condition; the second control module 14 is further configured to control the second photovoltaic optimization module 12 to stop working when the total power of the first output power and the second output power does not meet a preset power condition. The first output power and the second output power can be calculated based on the detected output voltage and output current.

[0042] Specifically, the preset power condition is that the total output power does not exceed a preset threshold power, for example, the preset threshold power is 1.2 times the rated power. If the total output power exceeds 1.2 times the rated power, it indicates that the photovoltaic optimizer is malfunctioning, and the first control module 13 and the second control module 14 respectively control the first photovoltaic optimization module 11 and the second photovoltaic optimization module 12 to stop working. It should be noted that the preset threshold power can also be other values, which are not limited in this application.

[0043] In some embodiments, the first control module 13 is further configured to detect the first output voltage of the first photovoltaic optimization module 11 when the first output power of the first photovoltaic optimization module 11 is the first target output power, and control the first photovoltaic optimization module 11 to stop working when the first output voltage does not meet the second preset voltage condition. When the first output power reaches the first target output power and the second output power reaches the target output power, if the first control module 13 detects that the first output voltage does not meet the first preset voltage condition, while the second control module 14 detects that the second output voltage meets the second preset voltage condition, then the first photovoltaic optimization module 11 is controlled to stop working, while the second photovoltaic optimization module 12 is controlled to work normally. This ensures that when one photovoltaic module malfunctions, the other photovoltaic module can still work normally, thereby ensuring that the corresponding photovoltaic module can output the target output power, realizing the independent operation of the two photovoltaic optimization modules in the photovoltaic optimizer, and ensuring that each photovoltaic optimization module can work in its optimal state.

[0044] It should be noted that the first control module 13 can also output the first output voltage and the second output current to the second control module 14 through the communication module 15; similarly, the second control module 14 can also output the first output voltage and the first output current to the first control module 13 through the communication module 15, so that each control module can understand the working status of each photovoltaic optimization module.

[0045] Please see Figure 3 In the photovoltaic optimizer, only one of the first photovoltaic optimization module 11 and the second photovoltaic optimization module 12 can be connected to a photovoltaic module to participate in operation. When the photovoltaic optimizer is connected to two photovoltaic modules simultaneously, it can control the power output of the two photovoltaic modules through the first control module 13, the second control module 14, and the communication module 15, so that the total output power reaches the maximum through the maximum power point tracking. Figure 3As shown, if only the first photovoltaic optimization module 11 is connected to the first photovoltaic module 21, and the second photovoltaic optimization module 12 is not connected to the second photovoltaic module 22, then the photovoltaic optimizer is controlled solely by the first control module 13 to perform maximum power point tracking on the output power of the first photovoltaic module 21, thereby optimizing the output power of the first photovoltaic module 21. Even when only one photovoltaic module is input, it can still ensure that the photovoltaic module outputs maximum power, thus maximizing power under different input conditions.

[0046] Please refer to the following: Figure 4 and Figure 5 In one embodiment, the first photovoltaic optimization module 11 includes a first switch Q1, a second switch Q2, a first capacitor C1, a first inductor L1, and a second capacitor C2. The first end of the first switch Q1 and the first end of the second switch Q2 are connected to the first control module 13. The second end of the first switch Q1 is connected to the first input terminal (terminal A in the figure) of the first photovoltaic optimization module 11. The third end of the first switch Q1 is connected to the second end of the first inductor L1 and the second switch Q2. The third end of the second switch Q2 is connected to the second output terminal (terminal F in the figure) of the first photovoltaic optimization module 11. One end of the first inductor L1 is connected to the third end of the first switch Q1, and the other end of the first inductor L1 is connected to the first output terminal (terminal E in the figure) of the first photovoltaic optimization module 11. One end of the first capacitor C1 is connected to the first end of the first switch Q1, and the other end of the first capacitor C1 is connected to the third end of the second switch Q2. One end of the second capacitor C2 is connected to the other end of the first inductor L1, and the other end of the second capacitor C2 is connected to the third end of the second switch Q2.

[0047] In this embodiment, the first switching transistor Q1 and the second switching transistor Q2 of the first photovoltaic optimization module 11 can both be field-effect transistors (FETs). The gates of both FETs are connected to the first control module 13 to receive control signals with a certain duty cycle. Specifically, the first and second FETs receive complementary control signals, such as PWM signals. When the first FET is turned on, the second FET is turned off, charging the first inductor L1, increasing the current of the first inductor L1. When the first FET is turned off and the second FET is turned on, since the current of the first inductor L1 cannot change abruptly, the current supplies power to the load 31, and the inductor current decreases. The first control module 13 outputs control signals with different duty cycles to control the changes in the output voltage, output current, and output power of the first photovoltaic optimization module 11.

[0048] In one embodiment, the second photovoltaic optimization module 12 includes a third switch Q3, a fourth switch Q4, a third capacitor C3, a second inductor L2, and a fourth capacitor C4. The first end of the third switch Q3 and the second end of the fourth switch Q4 are connected to the second control module 14. The second end of the third switch Q3 is connected to the first input terminal (terminal C in the figure) of the second photovoltaic optimization module 12. The third end of the third switch Q3 is connected to the second inductor L2 and the second end of the fourth switch Q4. The third end of the fourth switch Q4 is connected to the second output terminal (terminal H in the figure) of the second photovoltaic optimization module 12. One end of the second inductor L2 is connected to the third end of the fourth switch Q4, and the other end of the second inductor L2 is connected to the first output terminal (terminal G in the figure) of the second photovoltaic optimization module 12. One end of the third capacitor C3 is connected to the first end of the third switch Q3, and the other end of the third capacitor C3 is connected to the third end of the fourth switch Q4. One end of the fourth capacitor C4 is connected to the other end of the second inductor L2, and the other end of the fourth capacitor C4 is connected to the third end of the fourth switch Q4.

[0049] In this design, both the third switch Q3 and the fourth switch Q4 are field-effect transistors (FETs). The gates of both transistors are connected to the second control module 14 to receive control signals with specific duty cycles. Specifically, the third and fourth FETs receive complementary control signals, such as PWM signals. When the third FET is on, the fourth FET is off, charging the second inductor L2 and increasing its current. When the third FET is off and then on, since the current in the second inductor L2 cannot change abruptly, it supplies power to the load 31, causing the inductor current to decrease. The second control module 14 outputs control signals with different duty cycles to control the output voltage, output current, and output power of the second photovoltaic optimization module 12.

[0050] In one embodiment, the first control module 13 includes a first controller 131 and a first driver chip 132, and the second control module 14 includes a second controller 141 and a second driver chip 142. The first driver chip 132 is connected to a first terminal of a first switch Q1 and to the first controller 131. The first controller 131 controls the operation of the first driver chip 132, causing it to output control signals with different duty cycles to ensure the operation of the first photovoltaic optimization module 11. The second driver chip 142 is connected to a first terminal of a third switch Q3 and a fourth switch Q4. The second driver chip 142 is also connected to the second controller 141, which controls the operation of the second driver chip 142, causing it to output control signals with different duty cycles to ensure the operation of the second photovoltaic optimization module 12.

[0051] It should be noted that the first controller 131 and the second controller 141 in this embodiment include an MCU (Microcontroller Unit), such as the STM32F103C8T6. The first driver chip 132 and the second driver chip 142 can be NSD1624 and JW9611SOPB, and of course, driver chips and controllers with the same functions can be selected in other embodiments. This embodiment does not impose any restrictions on this.

[0052] As one embodiment, the communication module 15 includes a magnetic isolation circuit, which can be implemented using two current transformers. The controller's signal transmission is connected to one current transformer, and the control signal reception is connected to the other current transformer, thereby enabling communication transmission between the two controllers. It should be noted that the magnetic isolation circuit is a known technology, and its specific structure and operation will not be described in detail in this embodiment.

[0053] In one embodiment, the first photovoltaic optimization module 11 further includes a first resistor R1 and a second resistor R2. One end of the first resistor R1 is connected to the second input terminal (terminal B in the figure) of the first photovoltaic optimization module 11, and the other end of the first resistor R1 is connected to the third terminal of the second switching transistor Q2. One end of the second resistor R2 is connected to the other end of the fourth capacitor C4, and the other end of the second resistor R2 is connected to the second output terminal of the first photovoltaic optimization module 11. The first resistor R1 is used for sampling the input current of the first photovoltaic optimization module 11, and the second resistor R2 is used for sampling the output current of the first photovoltaic optimization module 11. The first control module 13 obtains the first input current through the first resistor R1 and the first output current through the second resistor R2.

[0054] In one embodiment, the second photovoltaic optimization module 12 further includes a third resistor R3 and a fourth resistor R4. One end of the third resistor R3 is connected to the second input terminal (terminal D in the figure) of the second photovoltaic optimization module 12, and the other end of the third resistor R3 is connected to the third terminal of the fourth switching transistor Q4. One end of the fourth resistor R4 is connected to the other end of the fourth capacitor C4, and the other end of the fourth resistor R4 is connected to the second output terminal of the second photovoltaic optimization module 12. The third resistor R3 is used for sampling the input current of the second photovoltaic optimization module 12, and the fourth resistor R4 is used for sampling the output current of the second photovoltaic optimization module 12. The second control module 14 obtains the second input current through the third resistor R3 and the second output current through the fourth resistor R4.

[0055] Please see Figure 6 To illustrate the working process of this photovoltaic optimizer in a photovoltaic power generation system in detail, the following specific embodiments are provided to explain the process of the photovoltaic optimizer, which includes the following steps: S10, Auxiliary power supply operation; S20. Check if the input voltage, input current and operating temperature are normal. If yes, proceed to step S30. Otherwise, check if the power-on is normal. S30, Perform maximum power point tracking; S40. Determine whether the target output power is output. If yes, proceed to step S50; otherwise, proceed to step S30. S50, detects output voltage and output current; S60. The control modules establish communication through the communication module. S70. Determine whether the total output current, total output voltage and total output power are normal. If yes, proceed to step S80; otherwise, proceed to step S90. S80, Normal Output; S90, control the corresponding photovoltaic optimization module to stop working.

[0056] If the first photovoltaic optimization module of the photovoltaic optimizer is connected to the first photovoltaic module, and the second photovoltaic optimization module is also connected to the second photovoltaic module, then after the photovoltaic optimizer is powered on, the auxiliary power supply starts to operate to supply power to the first and second control modules. The first and second control modules determine whether the first and second photovoltaic modules are malfunctioning based on their respective detection of input current, input voltage, and operating temperature. If both the first and second photovoltaic modules are in normal working condition, then the first control module controls the first photovoltaic optimization module to perform maximum power point tracking according to the MPPT algorithm, and the second control module controls the second photovoltaic optimization module to perform maximum power point tracking according to the MPPT algorithm, ensuring that both photovoltaic modules can output the corresponding target output power. If both the first and second photovoltaic optimization modules output the corresponding target output power, the two control modules acquire the output voltage, output current, and output power of their respective photovoltaic optimization modules. After communicating through the communication module, they calculate the total output voltage and total output power based on their respective output voltages and currents. Each control module then determines whether the total output voltage exceeds a second threshold voltage or whether the total output power exceeds a second threshold power, thereby determining whether the total output voltage and total output power are normal. If the total output voltage and total output power are abnormal, the first and second photovoltaic optimization modules are controlled to stop working. Conversely, if the total output voltage and total output power both meet the preset voltage and preset power conditions, then the first and second control modules control the corresponding photovoltaic optimization modules to output the corresponding target output power, ensuring the maximization of the total output power.

[0057] Of course, if the total output power and total output voltage are both normal, but the output voltage or output current of one photovoltaic optimization module is abnormal while the output voltage and output current of the other photovoltaic optimization module are normal, then the photovoltaic control module with abnormal output will stop working, while the photovoltaic optimization module with normal output will continue to output.

[0058] Please see Figure 7 This application also provides a control method for a photovoltaic optimizer, which is applied to the aforementioned photovoltaic optimizer. The control method includes: 100. When the first input voltage, first input current and first operating temperature of the first photovoltaic optimization module all meet the preset conditions, the first photovoltaic optimization module is controlled to perform maximum power point tracking; when the second input voltage, second input current and second operating temperature of the second photovoltaic optimization module all meet the preset conditions, the second photovoltaic optimization module is controlled to perform maximum power point tracking. 200. When the first output power of the first photovoltaic optimization module is the first target output power and the second output power of the second photovoltaic optimization module is the second target output power, the total output voltage and total output power of the first photovoltaic optimization module and the second photovoltaic optimization module are detected. 300. When the total output voltage does not meet the preset voltage condition or the total output power does not meet the preset power condition, the first photovoltaic optimization module and the second photovoltaic optimization module shall both stop working.

[0059] In this embodiment, when the photovoltaic optimizer is connected to two photovoltaic modules, if the input voltage, input current, and operating temperature of the first and second photovoltaic optimization modules are all normal, then the first and second photovoltaic optimization modules are controlled to perform maximum power point tracking (MPPT) processing, enabling both the first and second photovoltaic modules to output the target output power. When both the first and second photovoltaic modules reach the target output power, the output current, output voltage, and output power of the first and second photovoltaic optimization modules are continuously monitored. If the total output voltage of the photovoltaic optimizer exceeds a second threshold voltage or the total output power exceeds a preset threshold power, then the first and second photovoltaic optimization modules are controlled to stop working. Simultaneously, if the first output current of the first photovoltaic optimization module is abnormal, then the first photovoltaic optimization module is controlled to stop working; if the second output current of the second photovoltaic optimization module is abnormal, then the second photovoltaic optimization module is controlled to stop working, thereby ensuring the safety of the photovoltaic optimizer.

[0060] This application also provides a photovoltaic power generation system, which includes a first photovoltaic module, a second photovoltaic module, a load, and the aforementioned photovoltaic optimizer. The input terminal of the photovoltaic optimizer is connected to the first photovoltaic module and the second photovoltaic module, respectively, and the output terminal of the photovoltaic optimizer is connected to the load.

[0061] Please see Figure 8 In this embodiment, if the photovoltaic optimizer has two photovoltaic optimization modules, the photovoltaic optimizer includes two sets of input interfaces 101 and one set of output interfaces 102. One set of input interfaces 101 is used to connect to the first photovoltaic module, and the other set is used to connect to the second photovoltaic module. One of the output interfaces 102 corresponds to the first output terminal of the first photovoltaic optimization module, and the other corresponds to the second output terminal of the second photovoltaic optimizer. This set of output interfaces 102 is used to connect to the load. In this embodiment, by setting up this photovoltaic optimizer in the photovoltaic power generation system, when two photovoltaic modules are simultaneously input, the first control module and the second control module consider the power output of the two photovoltaic modules based on the communication module, and optimize the total output power to the maximum. When only one photovoltaic module is input, it also ensures that the module outputs maximum power, thereby maximizing power under different input conditions and improving the reliability of the entire photovoltaic power generation system. Since the photovoltaic optimizer has been described in detail above, it will not be repeated here.

[0062] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0063] The photovoltaic optimizer provided in the embodiments of this application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A photovoltaic optimizer, characterized by, The photovoltaic optimizer comprises: a first photovoltaic optimization module, first and second input ends of the first photovoltaic optimization module being used for being connected with a first photovoltaic component, a first output end of the first photovoltaic optimization module being used for being connected with a load; a second photovoltaic optimization module, first and second input ends of the second photovoltaic optimization module being used for being connected with a second photovoltaic component, a first output end of the second photovoltaic optimization module being connected with a second output end of the first photovoltaic component, and a second output end of the second photovoltaic optimization module being used for being connected with the load; a first control module, the first control module being connected with a control end of the first photovoltaic optimization module, and the first control module being used for controlling the first photovoltaic optimization module to optimize output power of the first photovoltaic component; a second control module, the second control module being connected with a control end of the second photovoltaic optimization module and the first control module respectively, and the second control module being used for controlling the second photovoltaic optimization module to optimize output power of the second photovoltaic component; a communication module, the communication module being connected with the first control module and the second control module respectively, and the communication module being used for transmitting communication information between the first control module and the second control module.

2. The photovoltaic optimizer of claim 1, wherein, The first control module is further used for detecting a first input voltage, a first input current and a first working temperature of the first photovoltaic optimization module, and when the first input voltage, the first input current and the first working temperature all satisfy preset conditions, the first photovoltaic optimization module is controlled to perform maximum power tracking. The second control module is further used for detecting a second output voltage, a second input current and a second working temperature of the second photovoltaic optimization module, and when the second output voltage, the second input current and the second working temperature all satisfy preset conditions, the second photovoltaic optimization module is controlled to perform maximum power tracking.

3. The photovoltaic optimizer of claim 2, wherein, The first control module is further used for detecting a first output voltage of the first photovoltaic optimization module when a first output power of the first photovoltaic optimization module is a first target output power, and the first output voltage is output to the second control module through the communication module. The second control module is further used for detecting a second output voltage of the second photovoltaic optimization module when a second output power of the second photovoltaic optimization module is a second target output power, and the second output voltage is output to the first control module through the communication module. The first control module is further used for controlling the first photovoltaic optimization module to stop working when a total voltage of the first output voltage and the second output voltage does not satisfy a first preset voltage condition, and the second control module is further used for controlling the second photovoltaic optimization module to stop working when a total output voltage of the first output voltage and the second output voltage does not satisfy the first preset voltage condition.

4. The photovoltaic optimizer of claim 2, wherein, The first control module is further configured to detect a first output current of the first photovoltaic optimization module when a first output power of the first photovoltaic optimization module is a first target output power, and output the first output current to the second control module through the communication module. The second control module is further configured to detect a second output current of the second photovoltaic optimization module when a second output power of the second photovoltaic optimization module is a second target output power, and output the second output current to the first control module through the communication module. The first control module is further configured to control the first photovoltaic optimization module to stop working when a total current of the first output current and the second output current does not satisfy a preset current condition, and the second control module is further configured to control the second photovoltaic optimization module to stop working when a total output current of the first output current and the second output current does not satisfy the preset current condition.

5. The photovoltaic optimizer of claim 2, wherein, The first control module is further configured to output the first output power to the second control module through the communication module when the first output power of the first photovoltaic optimization module is the first target output power, and the second control module is further configured to output the second output power to the first control module through the communication module when the second output power of the second photovoltaic optimization module is the second target output power. The first control module is further configured to control the first photovoltaic optimization module to stop working when a total power of the first output power and the second output power does not satisfy a preset power condition, and the second control module is further configured to control the second photovoltaic optimization module to stop working when a total output power of the first output power and the second output power does not satisfy the preset power condition.

6. The photovoltaic optimizer of claim 2, wherein, The first control module is further configured to detect a first output voltage of the first photovoltaic optimization module when the first output power of the first photovoltaic optimization module is the first target output power, and control the first photovoltaic optimization module to stop working when the first output voltage does not satisfy a second preset voltage condition.

7. The photovoltaic optimizer according to any of claims 1-6, characterized in that, The first photovoltaic optimization module comprises a first switch tube, a second switch tube, a first capacitor, a first inductor and a second capacitor. A first end of the first switch tube and a second end of the second switch tube are connected with the first control module, a second end of the first switch tube is connected with a first input end of the first photovoltaic optimization module, a third end of the first switch tube is connected with the first inductor and a second end of the second switch tube, a third end of the second switch tube is connected with a second output end of the first photovoltaic optimization module, one end of the first inductor is connected with the third end of the first switch tube, the other end of the first inductor is connected with a first output end of the first photovoltaic optimization module, one end of the first capacitor is connected with the first end of the first switch tube, the other end of the first capacitor is connected with the third end of the second switch tube, one end of the second capacitor is connected with the other end of the first inductor, and the other end of the second capacitor is connected with the third end of the second switch tube.

8. The photovoltaic optimizer according to any of claims 1-6, characterized in that, The second photovoltaic optimization module comprises a third switch tube, a fourth switch tube, a third capacitor, a second inductor and a fourth capacitor; The first end of the third switch tube and the second end of the fourth switch tube are connected with the second control module, the second end of the third switch tube is connected with the first input end of the second photovoltaic optimization module, the third end of the third switch tube is connected with the second end of the fourth switch tube and the second inductor, the third end of the fourth switch tube is connected with the second output end of the second photovoltaic optimization module, one end of the second inductor is connected with the third end of the fourth switch tube, the other end of the second inductor is connected with the first output end of the second photovoltaic optimization module, one end of the third capacitor is connected with the first end of the third switch tube, the other end of the third capacitor is connected with the third end of the fourth switch tube, one end of the fourth capacitor is connected with the other end of the second inductor, and the other end of the fourth capacitor is connected with the third end of the fourth switch tube.

9. A control method of a photovoltaic optimizer, characterized by, The control method is applied to the photovoltaic optimizer according to any one of claims 1-8; the control method comprises: When the first input voltage, the first input current and the first working temperature of the first photovoltaic optimization module all meet the preset conditions, the first photovoltaic optimization module is controlled to perform maximum power tracking; when the second input voltage, the second input current and the second working temperature of the second photovoltaic optimization module all meet the preset conditions, the second photovoltaic optimization module is controlled to perform maximum power tracking; When the first output power of the first photovoltaic optimization module is the first target output power and the second output power of the second photovoltaic optimization module is the second target output power, the total output voltage and the total output power of the first photovoltaic optimization module and the second photovoltaic optimization module are detected; When the total output voltage does not meet the preset voltage condition or the total output power does not meet the preset power condition, the first photovoltaic optimization module and the second photovoltaic optimization module are both controlled to stop working.

10. A photovoltaic power system, characterized by, The photovoltaic power generation system comprises a first photovoltaic component, a second photovoltaic component, a load and the photovoltaic optimizer according to any one of claims 1-8, the input ends of the photovoltaic optimizer are connected with the first photovoltaic component and the second photovoltaic component respectively, and the output end of the photovoltaic optimizer is connected with the load.

Images