Battery system and power generation device

Abstract

The utility model discloses a battery system and a power generation device. The battery system comprises a photovoltaic group string and an adjusting module, the photovoltaic group string comprises a first photovoltaic substring and a second photovoltaic substring which are connected in parallel; the first photovoltaic substring comprises a plurality of first power generation units which are connected in series, and the second photovoltaic substring comprises a plurality of second power generation units which are connected in series; the adjusting module is connected with the first photovoltaic substring and the second photovoltaic substring and is configured to obtain a first voltage output by the first photovoltaic substring; and the second photovoltaic substrings are subjected to voltage regulation processing based on the first voltage, so that the difference values between the output voltages of the second photovoltaic substrings and the first voltage are smaller than or equal to the preset voltage threshold value, mismatch between different photovoltaic substrings can be improved, the power generation efficiency is improved, and the service life of a battery is prolonged.

Description

Technical Field

[0001] The present application relates to the field of battery management, and in particular, to a battery system and a power generation device. Background Art

[0002] At present, in order to improve the power generation efficiency of batteries, different power generation units are often combined to supply power. Taking photovoltaic cells as an example, different types of power generation units are stacked to form a laminated assembly, and multiple battery assemblies are connected in series to form a photovoltaic string for power supply. This can further improve the existing photovoltaic energy conversion efficiency and reduce the cost of power generation through two or more bandgap light absorption layers. However, for photovoltaic strings, different types of power generation units have different electrical parameters, and it is difficult to match the battery version. In addition, different types of power generation units have different power generation conditions under different irradiation, different temperatures, and different shielding conditions. This may lead to different output voltages of different photovoltaic sub-strings, and then the upper and lower photovoltaic sub-strings form a loop to generate internal current, causing damage to the laminated solar panels. Summary of the Invention

[0003] This application proposes a battery system and a power generation device that can improve the mismatch between different photovoltaic sub-strings, thereby improving power generation efficiency and battery life.

[0004] The technical solution of this application is achieved as follows:

[0005] In a first aspect, an embodiment of the present application provides a battery system, which includes a photovoltaic string and a regulation module; the photovoltaic string includes a first photovoltaic sub-string and a second photovoltaic sub-string connected in parallel; the first photovoltaic sub-string includes a plurality of first power generation units connected in series, and the second photovoltaic sub-string includes a plurality of second power generation units connected in series; the regulation module is connected to the first photovoltaic sub-string and the second photovoltaic sub-string, and is configured to obtain a first voltage output by the first photovoltaic sub-string; and performs voltage regulation processing on the second photovoltaic sub-string based on the first voltage, so that the difference between the output voltage of the second photovoltaic sub-string and the first voltage is less than or equal to a preset voltage threshold.

[0006] Through the above technical means, since the regulation module can adjust the output voltage of the second photovoltaic sub-string to be the same as the output voltage of the first photovoltaic sub-string, the mismatch between different photovoltaic sub-strings is eliminated, and the charging efficiency and battery life are improved.

[0007] In some embodiments, the regulation module includes a control unit and an adjustment unit, the regulation unit is connected between the positive terminal, the negative terminal and the positive output terminal, the negative output terminal of the second photovoltaic sub-string; the control unit is configured to generate and output a first adjustment signal; the adjustment unit is connected to the control unit and the second photovoltaic sub-string, and is configured to receive and perform voltage regulation processing on the second photovoltaic sub-string based on the first adjustment signal, so that the difference between the output voltage between the positive output terminal and the negative output terminal of the second photovoltaic sub-string and the first voltage is less than or equal to a preset voltage threshold.

[0008] By means of the above technical means, the voltage of the second photovoltaic substring is regulated by the regulating unit, thereby eliminating the mismatch between different photovoltaic substrings.

[0009] In some implementations, the control unit is specifically configured to control a duty cycle of the generated first adjustment signal based on a voltage difference between a second voltage between a positive terminal and a negative terminal of the second photovoltaic substring, and output the first adjustment signal.

[0010] By means of the above technical means, the control unit is used to detect the voltage of the first photovoltaic substring, thereby adjusting the duty cycle of the first adjustment signal accordingly. Then, the adjustment unit eliminates the mismatch between different photovoltaic substrings according to the first adjustment signal.

[0011] In some embodiments, the regulating unit includes a boost chopper Boost circuit and / or a buck chopper Buck circuit; when the first voltage is greater than the second voltage of the second photovoltaic substring, the regulating unit is a boost chopper Boost circuit; when the first voltage is less than the second voltage of the second photovoltaic substring, the regulating unit is a buck chopper Buck circuit.

[0012] Through the above technical means, the voltage of the photovoltaic sub-string with the highest direct output voltage is monitored, and then the voltage of other photovoltaic sub-strings is boosted; or, the voltage of the photovoltaic sub-string with the lowest direct output voltage is monitored, and then the voltage of other photovoltaic sub-strings is stepped down; or, the voltage of the photovoltaic sub-string with an intermediate direct output voltage is monitored, and then the voltage of other photovoltaic sub-strings is stepped up or stepped down, thereby eliminating the mismatch between different photovoltaic sub-strings.

[0013] In some embodiments, the Boost circuit is connected in series between the positive terminal / negative terminal of the second photovoltaic substring and the positive output terminal / negative output terminal of the second photovoltaic substring, and the control terminal of the Boost circuit receives the first regulation signal; or, the Buck circuit is connected in series between the positive terminal / negative terminal of the second photovoltaic substring and the positive output terminal / negative output terminal of the second photovoltaic substring, and the control terminal of the Buck circuit receives the first regulation signal.

[0014] By controlling the closing / opening time of the first switch, the amplitude of the voltage boosting process is controlled so that the output voltages of all batteries are the same, thereby eliminating the mismatch problem between different photovoltaic substrings.

[0015] In some embodiments, the regulation module further includes a first power point tracking module, which is connected to the positive terminal and the negative terminal of the first photovoltaic sub-string; the first power point tracking module is configured to track the target power point of the first photovoltaic sub-string and adjust the output parameters of the first photovoltaic sub-string based on the tracking results so that it is in a target power state; wherein the output parameters of the first photovoltaic sub-string after adjustment by the first power point tracking module include a first voltage and / or a first current, and the first current refers to the current between the positive terminal and the negative terminal of the first photovoltaic sub-string.

[0016] Through the above technical means, a first power point tracking module is additionally provided for the first photovoltaic substring, and the target power point can be tracked by using the MPPT tracking technology to improve its output power.

[0017] In some embodiments, the regulation module further includes a second power point tracking module; the second power point tracking module is connected to the positive terminal and the negative terminal of the second photovoltaic substring; the second power point tracking module is configured to track the target power point of the second photovoltaic substring, and adjust the output parameters of the second photovoltaic substring based on the tracking results so that it is in a target power state; wherein the output parameters of the second photovoltaic substring after adjustment by the second power point tracking module include a second voltage and / or a second current, and the second current refers to the current between the positive terminal and the negative terminal of the second photovoltaic substring.

[0018] Through the above technical means, a second power point tracking module is additionally provided for the second photovoltaic substring, and the target power point can be tracked using the MPPT tracking technology to improve its output power.

[0019] In some embodiments, the regulation module also includes a first protection device; the first protection device is connected in series between the positive terminal of the first photovoltaic substring and the positive output end of the first photovoltaic substring, and is configured to allow unidirectional current to flow between the power generation unit in the first photovoltaic substring to the output end of the first photovoltaic substring.

[0020] Through the above technical means, the first protection device can be used to prevent the backflow from the second photovoltaic sub-string to the first photovoltaic sub-string, thereby improving the battery life.

[0021] In some embodiments, the regulation module further includes a second protection device, which is connected in series between the positive terminal of the first photovoltaic sub-string and the positive output end of the first photovoltaic sub-string; the second protection device is configured to control the positive terminal of the first photovoltaic sub-string and the positive output end of the first photovoltaic sub-string to be in a conductive state if the output power of the first photovoltaic sub-string is greater than or equal to a preset threshold; if the working state output power of the first photovoltaic sub-string is less than the preset threshold, the positive terminal of the first photovoltaic sub-string and the positive output end of the first photovoltaic sub-string are controlled to be in an open circuit state.

[0022] By means of the above technical means, when a fault or abnormality occurs in the first photovoltaic sub-string, the first photovoltaic sub-string is disconnected without causing any negative impact on the working state of the photovoltaic string group.

[0023] In some embodiments, the positive output end of the first photovoltaic sub-string and the positive output end of the second photovoltaic sub-string are connected in parallel to form the positive output end of the photovoltaic string, and the negative output end of the first photovoltaic sub-string and the negative output end of the second photovoltaic sub-string are connected in parallel to form the negative output end of the photovoltaic string; the battery system also includes an inverter; the inverter is connected to the positive output end and the negative output end of the photovoltaic string, and is configured to process the DC voltage output by the photovoltaic string to generate an AC voltage; wherein the inverter is configured with a third power point tracking module.

[0024] Through the above technical means, the output end of the photovoltaic string is connected to the inverter, and the third power point tracking module in the inverter will adjust the overall output power of the photovoltaic string again, thereby improving the power supply efficiency of the photovoltaic string.

[0025] In some embodiments, the first power generation unit and the second power generation unit are stacked to form a photovoltaic stacked cell, and the second power generation unit in the second photovoltaic sub-string has a different band gap from the light absorption layer of the first power generation unit; the photovoltaic string has an upper surface and a lower surface that are relatively arranged, and the first photovoltaic sub-string and the second photovoltaic sub-string are stacked between the upper surface and the lower surface.

[0026] Through the above technical means, for photovoltaic stacked cells, the mismatch problem of different photovoltaic sub-strings can be effectively eliminated, and the power generation efficiency can be improved by utilizing light-absorbing layers with different band gaps.

[0027] In a second aspect, an embodiment of the present application provides a power generation device, which includes a battery system as described in the first aspect.

[0028] Through the above technical means, since the regulation module in the battery system can adjust the output voltage of the second photovoltaic sub-string to be the same as the output voltage of the first photovoltaic sub-string, the mismatch between different photovoltaic sub-strings is eliminated, and the charging efficiency and battery life are improved.

[0029] An embodiment of the present application provides a battery system and a power generation device, wherein the battery system includes a photovoltaic string and a regulation module, wherein a first photovoltaic substring includes a plurality of first power generation units connected in series, and each second photovoltaic substring includes a plurality of second power generation units connected in series, and the second power generation units in the same second photovoltaic substring are of the same type, and the second power generation units in different second photovoltaic substrings are of the same or different types. Since the regulation module can adjust the output voltage of the second photovoltaic substring to be the same as the output voltage of the first photovoltaic substring, the mismatch between different photovoltaic substrings is eliminated, thereby improving the charging efficiency and battery life. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of power generation units, photovoltaic sub-strings and photovoltaic strings Figure 1

[0031] Figure 2 A schematic diagram of the structure of a battery system provided in an embodiment of the present application Figure 1 ;

[0032] Figure 3A A schematic diagram of the structure of a battery system provided in an embodiment of the present application Figure 2 ;

[0033] Figure 3B Schematic diagram 3 of the composition structure of a battery system provided in an embodiment of the present application;

[0034] Figure 4 A schematic diagram of the structure of a battery system provided in an embodiment of the present application Figure 4 ;

[0035] Figure 5 A schematic diagram of the structure of a battery system provided in an embodiment of the present application Figure 5 ;

[0036] Figure 6 A schematic diagram of the structure of a Boost circuit provided in an embodiment of the present application;

[0037] Figure 7 A schematic diagram of the structure of a battery system provided in an embodiment of the present application Figure 6 ;

[0038] Figure 8 A schematic diagram of the structure of the Buck circuit provided in an embodiment of the present application;

[0039] Figure 9A A schematic diagram of the structure of a battery system provided in an embodiment of the present application Figure 7 ;

[0040] Figure 9B A schematic diagram of the structure of a battery system provided in an embodiment of the present application Figure 8 ;

[0041] Figure 9C Schematic diagram 9 of the composition structure of a battery system provided in an embodiment of the present application;

[0042] Figure 10 A schematic diagram of the structure of a photovoltaic string provided in an embodiment of the present application;

[0043] Figure 11 A schematic diagram of the structure of a battery system provided in an embodiment of the present application Figure 10 ;

[0044] Figure 12 A schematic diagram of the structure of a battery system provided in an embodiment of the present application Figure 10 ;

[0045] Figure 13 A schematic diagram of a battery control method provided in an embodiment of the present application Figure 1 ;

[0046] Figure 14 A schematic diagram of a battery control method provided in an embodiment of the present application Figure 2 . DETAILED DESCRIPTION

[0047] In order to enable a more detailed understanding of the features and technical contents of the embodiments of the present application, the implementation of the embodiments of the present application is described in detail below with reference to the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0049] In the following description, reference is made to “some embodiments”, which describes a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0050] It should also be pointed out that the terms "first\second\third" involved in the embodiments of the present application are only used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present application described here can be implemented in an order other than that illustrated or described here.

[0051] In addition, in the embodiments of the present application, it is also necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0052] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the accompanying drawings. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the accompanying drawings. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0053] Furthermore, it should be understood that when a component is referred to as being "on," "connected to," "coupled to," or "contacting" another component, it can be directly on, connected to, coupled to, or contacting the other component, or intervening components may be present. Similarly, when a first component is referred to as being "electrically connected to," "electrically contacting," or "electrically coupled to" a second component, an electrical path exists between the first and second components that allows current to flow. This electrical path may include capacitors, coupled inductors, and / or other components that allow current to flow, even without direct contact between the conductive components.

[0054] Glossary:

[0055] PWM (Pulse Width Modulation): A technique for modulating the pulse width of a pulse signal.

[0056] MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor): Metal-Oxide Semiconductor Field-Effect Transistor;

[0057] IGBT (Insulate-Gate Bipolar Transistor): Insulated Gate Bipolar Transistor;

[0058] DC / DC (Direct Current / Direct Current): DC to DC conversion.

[0059] See Figure 1 , the meaning of the battery concept involved in this application is explained:

[0060] (1) Electronic unit

[0061] The electric power unit is a basic unit that can realize the mutual conversion between other forms of energy and electrical energy, such as thin film The sub-cell (through the preparation process) consists of a bottom electrode, a semiconductor layer and a top electrode in a cell (which can be a perovskite cell) The P1, P2, and P3 grooves in the battery are used to separate and connect in series and parallel), or the battery cells in non-thin-film batteries (such as crystalline silicon batteries). Generally speaking, the electronic unit does not have independent positive and negative terminals, but is connected in series and parallel ( Figure 1 Only perovskite batteries The full series structure of the sub-batteries of the battery is shown as an example, but it does not constitute a relevant limitation) to form a power generation unit and then independently The positive and negative electrodes are led out.

[0062] (2) Power generation unit

[0063] See Figure 1 The power generation unit refers to the smallest unit with independent positive and negative terminals, which is composed of multiple power generation units. The units are connected in series and parallel, and the specific method of series and parallel connection is not limited.

[0064] (3) Laminated components

[0065] See Figure 1 , multiple power generation units are stacked to form a laminated assembly, Figure 1 Only two power generation units are stacked for demonstration However, the number of power generation units stacked in the stack assembly is not limited. In addition, in this embodiment, the power generation units in the stack assembly The positive and negative terminals are led out of the elements respectively, that is, for the stacked assembly formed by stacking two power generation units, two positive terminals are led out. Terminal and 2 negative terminals, that is, four terminals.

[0066] (4) Photovoltaic substrings

[0067] See Figure 1 , multiple stacked components are connected in series in sequence, and the power generation unit strings at the same position in different stacked components are connected in series. They are connected to form photovoltaic sub-strings.

[0068] (4) Photovoltaic strings

[0069] See Figure 1 Multiple PV substrings are connected in parallel to form a PV string. Generally speaking, the power generation units within a PV substring are of the same type; different PV substrings may have the same or different types of power generation units. "Same type" here means the power generation principle, specific structure, specific materials, and dimensional parameters (within an acceptable tolerance) of the power generation units are identical.

[0070] Compared with single-layer modules, stacked solar modules (or stacked photovoltaic cells) can further improve the conversion efficiency of photovoltaic energy and reduce the cost of power generation by having two or more light-absorbing layers with different band gaps. For example, for stacked solar modules with transparent perovskite cells on the upper layer and crystalline silicon cells on the lower layer, due to the different electrical parameters of perovskite cells and crystalline silicon cells, a certain version design is required for matching, and the matching requirements for voltage or current are high. Moreover, the matching of voltage and current requires the cells to be cut and designed in series and parallel. This is currently difficult for perovskite cells and has a certain impact on efficiency and stability. In addition, different types of photovoltaic cells have different power generation conditions in the upper and lower photovoltaic units under different irradiation, different temperatures, and different shielding conditions. There is a deviation in the optimal working point, which will lead to a certain mismatch loss. For example, due to the different voltages of the power generation units in the upper and lower layers, the power generation units in the upper and lower layers form a loop to generate internal current, causing damage to the battery.

[0071] In some scenarios, perovskite cells and crystalline silicon cells can be used as two independent units to draw current and voltage respectively. Although this can avoid the problems caused by inconsistent photoelectric parameters, they are essentially still independent perovskite and crystalline silicon cell circuits. The operating parameters of the system end need to be designed separately, and the advantages of mechanical stacking components cannot be fully utilized.

[0072] The battery system provided in the embodiments of the present application can solve the above problems. The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0073] In one embodiment of this application, see Figure 2 , which is a schematic diagram of the composition structure of a battery system 10 provided in an embodiment of the present application Figure 1 .like Figure 2 As shown, the battery system 10 may include a photovoltaic string 20 and a regulation module 30. The photovoltaic string 20 includes a first photovoltaic sub-string 21 and a second photovoltaic sub-string 22 connected in parallel. The first photovoltaic sub-string 21 includes a plurality of first power generation units connected in series, and the second photovoltaic sub-string 22 includes a plurality of second power generation units connected in series.

[0074] The regulation module 30 is connected to the first photovoltaic sub-string 21 and the second photovoltaic sub-string 22, and is configured to obtain the first voltage output by the first photovoltaic sub-string 21; and perform voltage regulation processing on the second photovoltaic sub-string based on the first voltage so that the difference between the output voltage of the second photovoltaic sub-string and the first voltage is less than or equal to a preset voltage threshold.

[0075] It should be noted that voltage regulation refers to either step-down or step-up. In a first embodiment, the first photovoltaic substring 21 refers to the photovoltaic substring with the highest direct output voltage (also referred to as the second voltage) among the photovoltaic strings 20, and voltage regulation refers to step-up. In a second embodiment, the first photovoltaic substring 21 refers to the photovoltaic substring with the lowest direct output voltage among the photovoltaic strings 20, and voltage regulation refers to step-down. The specific value of the preset voltage threshold can be selected based on actual conditions, for example, set to the first voltage × 2%.

[0076] Please note that, see Figure 3A or Figure 3B , the number of the second photovoltaic substrings can be multiple, respectively represented as 22_1, 22_2...22_N. The power generation unit can be a battery of various types, various materials, and various power generation principles, such as primary batteries, secondary batteries, photovoltaic cells, wind power batteries... The types of the first power generation units in the first photovoltaic substring 21 are all the same, and the types of the first power generation units and the second power generation units are different; the types of the second power generation units in the same second photovoltaic substring 22 are the same, and the types of the second power generation units in different second photovoltaic substrings 22 are the same or different. As mentioned above, "the same type" means that the power generation principle, specific structure, specific material of each structure, and dimensional parameters (within the allowable error range) of the power generation unit are all the same. In addition, the number of power generation units in the first photovoltaic substring 21 and the number of power generation units in the second photovoltaic substring 22 can be the same or different.

[0077] Therefore, the second power generation unit in the first second photovoltaic substring is called the first type second power generation unit, the second power generation unit in the second second photovoltaic substring is called the second type second power generation unit... and the second power generation unit in the Nth type second photovoltaic substring is called the Nth type second power generation unit.

[0078] In some embodiments, as Figure 3A As shown, the regulation module 30 may perform voltage regulation processing on each second photovoltaic substring based on the first voltage.

[0079] In other embodiments, Figure 3BAs shown, the regulation module 30 only regulates the voltage of a portion of the second PV substrings 22_1 and 22_2 based on the first voltage, while not regulating the voltage of the other portion of the second PV substrings 22_3 to 22_N. That is, during the design phase, if the difference between the theoretical output voltage of the second PV substring and the theoretical output voltage of the first PV substring (i.e., the first voltage) is less than a preset ratio threshold (e.g., 2%), the regulation module 30 may not connect this portion of the second PV substring. If the difference between the theoretical output voltage of the second PV substring and the theoretical output voltage of the first PV substring (i.e., the first voltage) is greater than the preset ratio threshold (e.g., 2%), the regulation module 30 may connect this portion of the second PV substring and perform voltage regulation on it.

[0080] Assuming that the first photovoltaic sub-string 21 specifically refers to the photovoltaic sub-string with the highest direct output voltage in the photovoltaic string 20, taking the photovoltaic string as a photovoltaic stacked cell as an example, specific descriptions of several first photovoltaic sub-strings and second photovoltaic sub-strings are provided.

[0081] Example 1: For the photovoltaic string 20 formed by stacking crystalline silicon photovoltaic substrings and perovskite photovoltaic substrings, since the output voltage of the perovskite cell is higher than the output voltage of the crystalline silicon cell, the first photovoltaic substring 21 refers to the perovskite photovoltaic substring, and the second photovoltaic substring 22 refers to the crystalline silicon photovoltaic substring.

[0082] Example 2: For a photovoltaic substring group 20 formed by stacking three crystalline silicon photovoltaic substrings, perovskite photovoltaic substrings, and copper indium gallium selenide photovoltaic substrings, the first photovoltaic substring 21 is a perovskite photovoltaic substring, and the second photovoltaic substring 22 can refer to a crystalline silicon photovoltaic substring and a copper indium gallium selenide photovoltaic substring.

[0083] Example three, for the stacked photovoltaic sub-string formed by stacking a crystalline silicon photovoltaic sub-string, a perovskite photovoltaic sub-string, and a perovskite photovoltaic sub-string, the first photovoltaic sub-string 21 refers to two perovskite photovoltaic sub-strings (at the same time, since the output voltage difference between the two perovskite photovoltaic sub-strings is extremely small, only one of the perovskite photovoltaic sub-strings needs to be voltage monitored), and the second photovoltaic sub-string 22 refers to a crystalline silicon photovoltaic sub-string.

[0084] Example 4: For a stacked photovoltaic sub-string formed by stacking a crystalline silicon photovoltaic sub-string, a crystalline silicon photovoltaic sub-string, and a perovskite photovoltaic sub-string, the first photovoltaic sub-string 21 refers to a perovskite photovoltaic sub-string, and the second photovoltaic sub-string 22 refers to two crystalline silicon photovoltaic sub-strings.

[0085] …

[0086] In addition, the photovoltaic string 20 can also be a combination of sodium batteries, lithium batteries, etc. connected in parallel to form a battery, or can be generated by combining any other form of power generation units.

[0087] It is also necessary to note that see Figure 2 The regulating module 30 is connected to the output end out0+ / out0- of the first photovoltaic substring 21 to obtain a first voltage; at the same time, the regulating module 30 is also connected between the positive and negative terminals and the positive and negative output ends of the second photovoltaic substring 22, thereby regulating so that the output voltage of the second photovoltaic substring 22 is almost the same as the first voltage.

[0088] In this way, in the embodiment of the present application, by monitoring the voltage of a certain photovoltaic sub-string (i.e., the first photovoltaic sub-string 21) in the photovoltaic string 20, and adjusting the output voltage of the second photovoltaic sub-string 22 to be consistent with the output voltage of the first photovoltaic sub-string 21, the output voltages of different photovoltaic sub-strings in the photovoltaic string 20 are all the same, and the difficulty of matching the types of the photovoltaic string 20 is reduced; on the other hand, since the output voltages of different photovoltaic sub-strings are all the same, no loop will be formed between different photovoltaic sub-strings to generate current, and the life of the photovoltaic sub-strings can also be improved.

[0089] In some embodiments, see Figure 4 The regulating module 30 includes a control unit 31 and a regulating unit 32, and the regulating unit 32 is connected between the positive terminal +, the negative terminal - and the positive output terminal out1+, the negative output terminal out1- of the second photovoltaic substring 22;

[0090] The control unit 31 is configured to generate and output a first adjustment signal Con1;

[0091] The regulating unit 32 is connected to the control unit 31 and the second photovoltaic substring 22, and is configured to receive and, based on the first regulating signal Con1, perform voltage regulation on the second photovoltaic substring 22 so that the difference between the output voltage between the positive output terminal out1+ and the negative output terminal out1- of the second photovoltaic substring 22 and the first voltage is less than or equal to a preset voltage threshold.

[0092] See Figure 5 , the number of second photovoltaic substrings can be multiple. If A second photovoltaic substrings are connected to the regulation module 30, the number of regulation units is also A. That is, the regulation module 30 includes a control unit 31 and A regulation units (in Figure 5 They are represented as 32_1, 32_2...32_N respectively. Figure 5 (Taking A=N as an example for illustration), the i-th regulating unit is connected between the positive terminal, negative terminal and the positive output terminal, negative output terminal of the i-th second photovoltaic substring, that is, the regulating unit 32_1 is connected between the positive terminal +, negative terminal - of the second photovoltaic substring 22_1 and its output terminal out1+ / out1-, and the regulating unit 32_2 is connected between the positive terminal +, negative terminal - of the second photovoltaic substring 22_2 and its output terminal out2+ / out2-... i is a positive integer less than or equal to A.

[0093] In a specific embodiment, the control unit 31 is connected to both the first photovoltaic sub-string 21 and the second photovoltaic sub-string 22 (omitted in the drawing); the control unit 31 is specifically configured to control the duty cycle of the first adjustment signal Con1 generated based on the voltage difference between the first voltage and the second voltage between the positive terminal + and the negative terminal - of the second photovoltaic sub-string 22, and output the first adjustment signal.

[0094] Please note that, see Figure 5 , the control unit 31 is configured to generate A adjustment signals (at Figure 5 and adjusting the duty cycle of the i-th first regulation signal Coni based on the voltage difference between the first voltage and the second voltage at the positive terminal and the negative terminal of the i-th second photovoltaic substring.

[0095] The i-th regulation unit 32_i is connected to the control unit 31 and the i-th second photovoltaic substring 22_i, and is configured to receive and, based on the i-th first regulation signal Coni, perform voltage regulation on the i-th second photovoltaic substring 22_i so that a difference between an output voltage between a positive output terminal and a negative output terminal of the i-th second photovoltaic substring 22_i and the first voltage is less than or equal to a preset voltage threshold.

[0096] As mentioned above, the voltage regulation process may include a step-down process or a step-up process. For those regulation units that need to perform step-down processing, a chopper circuit (i.e., a Buck circuit) may be used; for those regulation units that need to perform step-up processing, a Boost circuit may be used.

[0097] Specifically, for the first specific embodiment mentioned above: see Figure 5 Under normal operating conditions, the first voltage directly output by the first photovoltaic substring 21 is definitely greater than the second voltage directly output by the second photovoltaic substring, that is, the photovoltaic string with the highest output voltage is selected as the first photovoltaic substring 21. Then, the regulation unit is specifically a boost chopper Boost circuit; the Boost circuit is connected in series between the positive terminal + / negative terminal - of the second photovoltaic substring and the positive output terminal (outi+) / negative output terminal (outi-) of the second photovoltaic substring, and the control terminal of the Boost circuit receives the first regulation signal.

[0098] See Figure 5 A boost circuit is a DC voltage conversion circuit, specifically a non-isolated DC converter with an output voltage ≥ input voltage. It should be understood that the device types, number of devices, and device connections are the same across different boost circuits. The following provides an exemplary structure of a boost circuit.

[0099] See Figure 5 , Figure 5 Only the adjustment unit 32_1 is used as an example for marking. Figure 5 As shown, the Boost circuit includes a first switch 42 , a first diode 43 , a first inductor 41 , and a first capacitor 44 .

[0100] The first end of the first inductor 41 is connected to the positive terminal + of the second photovoltaic substring, that is, the first end of the first inductor in the adjustment unit 32_1 is connected to the positive terminal + of the second photovoltaic substring 22_1, the first end of the first inductor in the adjustment unit 32_2 is connected to the positive terminal + of the second photovoltaic substring 22_2... and the first end of the first inductor in the adjustment unit 32_N is connected to the positive terminal + of the second photovoltaic substring 22_N.

[0101] The second end of the first inductor 41 and the first end of the first switch 42 are connected to the input end of the first diode 43, and the output end of the first diode 43 is connected to the positive output end of the second photovoltaic substring. That is, the output end of the first diode 43 in the adjustment unit 32_1 is connected to out1+, the output end of the first diode in the adjustment unit 32_2 is connected to out2+, and the output end of the first diode in the adjustment unit 32_N is connected to outN+.

[0102] The second end of the first switch 42, the negative terminal of the second PV substring, and the second end of the first capacitor 44 are connected to the negative output end of the second PV substring. The control end of the first switch 42 receives a first regulation signal. Specifically, the control end of the first switch 42 in the regulation unit 32_1 receives the first first regulation signal Con1, the control end of the first switch 42 in the regulation unit 32_2 receives the second first regulation signal Con2, and so on. The control end of the first switch 42 in the regulation unit 32_N receives the Nth first regulation signal ConN. The control end signal of the first switch 42 determines whether the circuit between its first and second ends is open or closed.

[0103] It is worth noting that although the types, quantities and connection relationships of components of different adjustment units are the same, since the output voltages of different second photovoltaic sub-strings are different, that is, the boost requirements of different second photovoltaic sub-strings may be different, the electrical parameters of specific components of different adjustment units may be different. For example, the inductance of the first inductor 41 and the capacity of the first capacitor 44 in different adjustment units may be the same or different.

[0104] It should be noted that the first switch 42 can adopt various types of switches, such as IGBT transistors, MOSFET transistors, etc. The duty cycle of the first adjustment signal can control the on / off time of the first switch 42, thereby boosting the output voltage of the second photovoltaic sub-string to the required voltage value.

[0105] In addition to the above structures, Boost circuits also have more topology types, see Figure 6 In (a), the Boost circuit can also include an additional 4 diodes; or as Figure 6 In (b) of FIG6 , the first switch in the Boost circuit can be replaced with a single-pole double-throw switch. Alternatively, in (b) of FIG6 , the Boost circuit can further include a resistor as a load. In short, any type of Boost circuit topology capable of achieving a voltage boost function can be applied to this embodiment.

[0106] Regarding the second specific embodiment mentioned above: please refer to Figure 7 Under normal operating conditions, the first voltage directly output by the first photovoltaic substring 21 is lower than the second voltage of the second photovoltaic substring. Therefore, the photovoltaic substring with the lowest voltage is selected as the first photovoltaic substring 21. Therefore, the regulation unit is specifically a step-down (Buck) circuit, a non-isolated DC converter with an output voltage ≤ input voltage. The Buck circuit is connected in series between the positive terminal (+) / negative terminal (-) of the second photovoltaic substring and the positive output terminal (outi+) / negative output terminal (outi-) of the second photovoltaic substring, and a control terminal of the Buck circuit receives a first regulation signal.

[0107] The following is an example of the specific structure of the Buck circuit. Figure 7 As shown, the Buck circuit includes a second switch 42', a second diode 43', a second inductor 41', and a second capacitor 44'. The control end of the second switch 42' receives the first regulation signal, the first end of the second switch 42' is connected to the positive terminal + of the second photovoltaic substring, the second end of the second switch 42' and the output end of the second diode 43' are connected to the first end of the second inductor 41'; the second end of the second inductor 41' and the second end of the second capacitor 44' are both connected to the positive output end of the second photovoltaic substring; the negative terminal - of the second photovoltaic substring, the input end of the second diode 43', and the first end of the second capacitor 44' are all connected to the negative output end of the second photovoltaic substring.

[0108] For the third specific embodiment mentioned above: the voltage directly output by the first photovoltaic substring (i.e., the first voltage) is greater than the second voltage of the second photovoltaic substring of the first part, and the voltage directly output by the first photovoltaic substring (i.e., the first voltage) is less than the second voltage of the second photovoltaic substring of the second part; then, the regulating unit connected to the second photovoltaic substring of the first part is specifically a boost chopper Boost circuit, and the regulating unit connected to the second photovoltaic substring of the second part is specifically a buck chopper Buck circuit.

[0109] In addition to the above structures, Buck circuits also have more topology types, see Figure 8 In (a), the Buck circuit can also include an additional resistor as a load; or Figure 8 In (b), additional capacitors can be added to the Buck circuit. In short, any type of Buck circuit topology that can achieve a step-down function can be applied to this embodiment.

[0110] In addition, if the first voltage directly output by the first photovoltaic substring 21 is close to the second voltage of the second photovoltaic substring, or the voltage magnitude is greatly affected by the working conditions; for example, under some normal working conditions, the second voltage of the second photovoltaic substring is less than the first voltage, and under other normal working conditions, the second voltage of the second photovoltaic substring is greater than the first voltage, then the regulating unit 32 connected to the second photovoltaic substring may also include a Boost circuit and a Buck circuit connected in series.

[0111] At this time, the adjustment unit 32 may also include a data selector. If the second voltage is less than the first voltage, the data selector sends the first adjustment signal to the Boost circuit, and at the same time controls the Buck circuit to be in a fully open state (i.e., the Buck circuit only transmits the signal but does not change the signal voltage value) by sending a signal with a fixed level value to the Buck circuit; if the second voltage is greater than the first voltage, the data selector sends the first adjustment signal to the Buck circuit, and at the same time controls the Boost circuit to be in a fully open state (i.e., the Boost circuit only transmits the signal but does not change the signal voltage value) by sending a signal with a fixed level value to the Boost circuit.

[0112] In some embodiments, if the difference between the operating parameters of the multiple second power generation units is less than or equal to a preset error threshold, the multiple second power generation units can share the same first adjustment unit. For example, the control unit 31 can adjust the duty cycle of the first adjustment signal based on the difference between the second voltage and the first voltage of one of the second power generation units, and send the first adjustment signal to the shared first adjustment unit. The shared first adjustment unit may include multiple Buck circuits or multiple Boost circuits, each connected to a different second power generation unit, and these Buck circuits or Boost circuits all operate based on the received first adjustment signal.

[0113] In some embodiments, see Figure 5 or Figure 7 The regulation module 30 also includes a first protection device 33; the first protection device 33 is connected in series to the positive terminal + of the first photovoltaic substring 21 and the positive output terminal (out0+) of the first photovoltaic substring 21, and is configured to allow a unidirectional current to flow between the power generation unit in the first photovoltaic substring 21 and the output terminal of the first photovoltaic substring 21.

[0114] In this way, the first protection device 33 can prevent the current from flowing in the reverse direction to the first photovoltaic substring 21, thereby avoiding damage to the battery device. The first protection device 33 can be implemented by a diode, or the first protection device 33 can also be implemented by a transistor, such as an IGBT transistor or a MOSFET transistor.

[0115] In some embodiments, see Figure 9A The regulation module 30 further includes a first power point tracking module 34 connected to the positive terminal + and the negative terminal - of the first photovoltaic substring 21. The first power point tracking module 34 is configured to track the target power point of the first photovoltaic substring 21 and adjust the output parameters of the first photovoltaic substring 21 based on the tracking results to maintain the target power state. The output parameters of the first photovoltaic substring 21 adjusted by the first power point tracking module 34 include a first voltage and / or a first current. The first current refers to the current generated between the positive terminal + and the negative terminal - of the first photovoltaic string 21.

[0116] In other embodiments, see Figure 9BThe regulation module 30 further includes a second power point tracking module 35. The second power point tracking module 35 is connected to the positive terminal + and the negative terminal - of the second PV substring. The second power point tracking module 35 is configured to track the target power point of the connected second PV substring and adjust the output parameters of the second PV substring based on the tracking results to maintain the target power state (e.g., maximum power state). The output parameters of the second PV substring adjusted by the second power point tracking module 35 include a second voltage and / or a second current. The second current refers to the current between the positive terminal and the negative terminal of the second PV substring.

[0117] In one example, the target power point may be a maximum power point.

[0118] Figure 9B Only one second power point tracking module 35 is used as an example, but the number of second power point tracking modules 35 can be greater. Figure 9B In the embodiment, the second power point tracking module 35 is connected to the second photovoltaic substring 22_N. In fact, any one or more second photovoltaic substrings can be connected to their own second power point tracking module 35, so that they are in the target power state, thereby improving the battery working efficiency.

[0119] In some embodiments, if the difference between the operating parameters of the plurality of second power generation units is less than or equal to a preset error threshold, the plurality of second power generation units may share the same second power point tracking module 35 .

[0120] It should be noted that both the first power point tracking module 34 and the second power point tracking module 35 can use an MPPT controller (Maximum Power Point Tracking) time, which independently carries an MPPT algorithm and independent boost and buck circuits. For example, the boost circuit can be a Boost circuit and the buck circuit can be a Buck circuit. The specific working principle is to monitor the voltage and current of the photovoltaic substring in real time, calculate the current target power point, and then adjust the load so that the output characteristics of the photovoltaic substring are at the target power point. It is particularly suitable for photovoltaic cells.

[0121] It should be noted that the target power state may be a maximum power state, that is, the first power point tracking module 34 is used to optimize the output parameters of the first photovoltaic substring 21, thereby increasing the output power of the first photovoltaic substring 21. The second power point tracking module 35 is used to optimize the output parameters of the second photovoltaic substring, thereby increasing the output power of the second photovoltaic substring.

[0122] For example, without the second power point tracking module 35, assume that the second PV string generates a second current of 2A and a second voltage of 120V, resulting in an output power of 240W. After the second power point tracking module 35 is installed, it adjusts the load and other measures to reduce the second current generated by the second PV string to 1.8A and the second voltage to 200V, resulting in an output power of 360W. This optimizes the output power of the second PV string. The above values ​​are for illustrative purposes only and are not intended to be limiting or representative of actual operating conditions.

[0123] At the same time, the regulation module 30 does not change the output power of the second PV substring. That is, when the regulation module 30 steps up or down the voltage, the corresponding current will also change synchronously. For example, assuming the first voltage output by the first PV substring 21 is 100V, the second current of the second PV substring is 1.8A, and the second voltage is 200V, after regulation by the regulation module 30, the output voltage of the second PV substring is 100V, and its output current is also adjusted to 3.6A. The power before and after regulation is 360W.

[0124] Therefore, the power point tracking module 35 is used to increase the output power of the power generation unit, and the regulation module 30 is used to solve the voltage mismatch problem between different photovoltaic sub-strings.

[0125] In some other embodiments, see Figure 9C The adjustment module 30 may include the aforementioned first power point tracking module 34 and second power point tracking module 35 at the same time.

[0126] In some embodiments, see Figures 9A to 9C The regulation module 30 further includes a second protection device 36, which is connected in series between the positive terminal of the first photovoltaic substring 21 and the positive output end of the first photovoltaic substring 21; the second protection device 36 is configured to control the positive terminal of the first photovoltaic substring and the positive output end of the first photovoltaic substring to be in a connection state if the output power of the first photovoltaic substring 21 is greater than or equal to a preset threshold, so that the outputs of all photovoltaic substrings are valid; if the output power of the first photovoltaic substring 21 is less than the preset threshold, the positive terminal of the first photovoltaic substring and the positive output end of the first photovoltaic substring are controlled to be in an open circuit state, so that the output of the first photovoltaic substring is invalid and only the output of the second photovoltaic substring is valid.

[0127] Exemplarily, the second protection device 36 may be a switch device (which may be formed by a variety of controllable switches) or a transistor, and the first protection device 33 and the second protection device 36 may be implemented by the same transistor.

[0128] At the same time, the regulation module 30 is further configured to perform voltage regulation processing on each second photovoltaic sub-string when the output of the first photovoltaic sub-string is valid; or, when the output of the first photovoltaic sub-string 21 is invalid, not perform voltage regulation processing on each second photovoltaic sub-string, and directly transmit the second voltage between the positive terminal and the negative terminal of the second photovoltaic sub-string to form the output voltage of its positive output end and negative output end.

[0129] It should be noted that if the first PV substring 21 is damaged or its output power is too low, it can be considered that the first PV substring 21 is in an abnormal operating state, and the second protection device 36 is used to disconnect the first PV substring 21. At the same time, the output of the second PV substring is no longer processed. In other words, when the second protection device 36 is disconnected, the first regulation signal output by the control unit 31 will cause the first switch in the regulation unit to be in a normally open state.

[0130] It should be noted that in Figures 9A to 9C In the embodiment, the second protection device 36 is closer to the positive terminal of the first photovoltaic substring 21, and the first protection device 33 is closer to the positive output end of the first photovoltaic substring 21, but this does not constitute a specific limitation, and the positions of the two can be exchanged.

[0131] In some embodiments, see Figures 9A to 9C The positive output end of the first photovoltaic substring 21 and the positive output end of each second photovoltaic substring are connected in parallel to form the positive output end of the photovoltaic string, that is, out0+, out1+, out2+...outN+ are connected in parallel to form out+, and the negative output end of the first photovoltaic substring and the negative output end of each second photovoltaic substring are connected in parallel to form the negative output end of the photovoltaic string, that is, out0-, out1-, out2-...outN- are connected in parallel to form out-.

[0132] The battery system 10 also includes an inverter 50; the inverter 50 is connected to the positive output terminal out+ and the negative output terminal out- of the photovoltaic string 20, and is configured to process the DC voltage output by the photovoltaic string 20 to generate an AC voltage; wherein the inverter 50 is configured with a third power point tracking module.

[0133] Thus, during operation of the battery system 10, the output voltages of the first PV substring 21 and the N second PV substrings are connected in parallel to produce a DC voltage. The inverter 50 converts the DC voltage into an AC voltage to power the subsequent power modules. Simultaneously, the inverter 50 includes a built-in third power point tracking module to further adjust the overall output power of the PV string 20, thereby improving the power supply efficiency of the PV string 20.

[0134] In some embodiments, the battery system 10 further includes a communication module; the communication module is configured to collect operating parameters of the battery system 10 and send the collected operating parameters to a target server.

[0135] It should be noted that the communication module can utilize a programmable logic controller (PLC). The operating parameter selectivity of the battery system 10 includes, but is not limited to, the following parameters: the voltage / current between the local positive and negative terminals and the voltage / current between the positive and negative output terminals of the first photovoltaic substring 21; the voltage / current between the local positive and negative terminals and the voltage / current between the positive and negative output terminals of the second photovoltaic substring; and the duty cycle of the first regulation signal, thereby enabling remote data transmission and performance self-diagnosis alarms.

[0136] At present, the application of new energy batteries in life and industry is becoming more and more extensive. New energy batteries are not only used in energy storage power supply systems such as hydropower, thermal power, wind power and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as in aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding. A power generation sub-unit refers to a basic unit that can realize the mutual conversion of other forms of energy and electrical energy, which can be used to make a power generation unit, thereby being used to supply power to electrical devices. The power generation unit can be a secondary battery, and a secondary battery refers to a photovoltaic sub-string that can be activated by charging the active material after the power generation unit is discharged and can continue to be used. The power generation unit can be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc. The photovoltaic sub-string can also be a photovoltaic cell, and the embodiments of the present application are not limited to this.

[0137] In some embodiments, the photovoltaic string 20 includes a plurality of photovoltaic stacked cells connected in series, which are used to convert absorbed light energy into electrical energy; the photovoltaic string 20 also includes an upper surface and a lower surface, and the first photovoltaic sub-string 21 and N second photovoltaic sub-strings are stacked between the upper surface and the lower surface, and the band gap of the light absorption layer of the first power generation unit and any second power generation unit is different.

[0138] Please note that, see Figure 10A first power generation unit and a second power generation unit are stacked and packaged to form a laminated assembly. Each laminated assembly has four output ports: the positive and negative output terminals of the first power generation unit and the positive and negative output terminals of the second power generation unit. Different laminated assemblies are connected in series to form a photovoltaic string 20. Simply put, for the photovoltaic string 20 of the present application, different power generation units in the laminated assembly lead out output terminals respectively, and power generation units of corresponding heights in different laminated assemblies are connected in series to form photovoltaic sub-strings. Different photovoltaic sub-strings are connected in parallel to produce the final output.

[0139] Figure 10 The stacking structure of the photovoltaic string 20 is illustrated by taking the first power generation unit 21 as a perovskite cell and the second power generation unit 22 as a crystalline silicon cell as an example. Since the perovskite cell has a wider absorption band gap, the perovskite cell is located in the upper layer and the crystalline silicon cell is located in the lower layer. However, this does not limit the specific positions of the first power generation unit 21 and the second power generation unit 22. In other embodiments, the perovskite cell in the upper layer can also be selected as the second power generation unit 22, and the crystalline silicon cell in the lower layer can be selected as the first power generation unit 21.

[0140] Simply put, a photovoltaic tandem cell consists of two or more photovoltaic substrings (in this embodiment, photovoltaic substrings can also be referred to as photovoltaic units). Different photovoltaic substrings contain light-absorbing layers with different band gaps. Using light-absorbing layers with different band gaps improves the existing photovoltaic energy conversion efficiency and reduces the cost of power generation.

[0141] In summary, this embodiment provides a battery system 10, the system composition of which includes a photovoltaic string 20 + a regulation module 30 + an inverter 50, which is used to solve the mismatch problem of different photovoltaic sub-strings in a stacked photovoltaic string. Specifically, in the photovoltaic string, it includes multiple mechanical stacked components (a first power generation unit and a second power generation unit aligned in the vertical direction can be regarded as a mechanical stacked component), and each power generation unit in the same mechanical stacked component has two positive and negative terminals (such as a perovskite-crystalline silicon mechanical stacked component, which has two sets of positive and negative outputs respectively) for series convergence; at the same time, a string-level regulation module is also provided, the purpose of which is to adjust the output voltage of the string formed by connecting different mechanical stacked components in series to be consistent and then output in parallel, thereby solving the parallel mismatch problem of the stacked components; the string-level regulation module includes two or more inputs, which are respectively connected to the strings formed by connecting different photovoltaic sub-strings in series of the stacked components, and are aggregated to one output after being connected in parallel.

[0142] See Figure 11 The following provides a specific implementation detail by taking the photovoltaic string 20 as an example, which is specifically a photovoltaic laminated cell (ie, photovoltaic string 20) formed by stacking two photovoltaic sub-strings (also referred to as photovoltaic units). Figure 11As shown, the first photovoltaic substring 21 includes a plurality of perovskite cells connected in series, and the second photovoltaic substring 22 includes a plurality of perovskite cells connected in series.

[0143] (1) The photovoltaic substrings located in the upper layer (front, light-facing side) include transparent photovoltaic modules, and the photovoltaic substrings located in the lower layer can be transparent photovoltaic modules or opaque photovoltaic modules, single-sided modules or double-sided modules. The specific design, type, and structure of the photovoltaic substrings in the upper and lower layers are not restricted.

[0144] (2) The photovoltaic substrings of the upper and lower layers are encapsulated between the upper surface and the lower surface, the upper surface is a light-transmitting surface, and the lower surface is a light-transmitting surface or an opaque surface.

[0145] (3) A transparent insulating material layer is provided between the upper photovoltaic sub-string and the lower photovoltaic sub-string, which can be made of film, glass or other materials.

[0146] (4) Photovoltaic laminated cells need to be encapsulated. The encapsulation form is not limited, and the laminated components can be equipped with or without frames.

[0147] (5) The positive and negative terminals of the upper photovoltaic substring and the lower photovoltaic substring are respectively led out, i.e., the positive output terminal and the negative output terminal, and the leading-out method and the leading-out position are not limited.

[0148] The upper and lower PV substrings together form a PV string. Since the upper and lower PV substrings have different absorption band gaps, the magnitude of their direct output voltage after absorbing light energy is different, so the PV string will have mismatch. Figure 11 In this embodiment, a regulation module 30 is introduced at the end of the photovoltaic string. After the voltage and current are regulated by the regulation module, the output voltage is output to the inverter, which can improve the mismatch problem of the upper and lower photovoltaic sub-strings in the photovoltaic string.

[0149] See Figure 12 , providing a detailed introduction to the adjustment module 30 in a specific scenario.

[0150] (6) See Figure 12 For PV string 20, the first PV substring 21 (the PV substring with the highest direct output voltage) formed by the series connection of perovskite cells is connected to an input path of the regulation module 30. This path uses a series structure of a first protection device 33 and a second protection device 36, and is equipped with an input voltage monitoring function, using the monitored first voltage as the output voltage reference of the regulation module. For example, the first protection device 33 can be a diode, and the second protection device 36 can be an intelligent switch, or the first and second protection devices 33 and 36 can be implemented using the same transistor (MOSFET or IGBT).

[0151] (7) See Figure 12In PV string 20, a second PV substring 22 (a PV string with a lower direct output voltage) formed by a series connection of crystalline silicon cells is connected to another input of regulation module 30. This path uses a boost circuit to boost the voltage after DC / DC conversion. The boosted voltage amplitude is determined by controlling the on-off ratio (i.e., duty cycle) of the first switch 42 in the boost circuit. This ensures that the output voltage amplitude of the second PV substring 22 is equal to the output voltage (i.e., the first voltage) of the first PV substring 21 to the right of the first protection device 33. The first switch 42 can be a MOSFET or IGBT transistor. Subsequently, the first and second PV substrings 21, 22 can be directly connected in parallel, eliminating the voltage mismatch problem.

[0152] (8) The first photovoltaic substring 21 is also equipped with an MPPT module (i.e., the second power point tracking module 35) with a built-in MPPT tracking algorithm. By collecting the output current and voltage of the perovskite cell, the algorithm calculates and outputs a PWM control signal. The PWM control signal is used to control the DC / DC converter built into the MPPT module, thereby adjusting the load size and ultimately achieving the target power point tracking of the perovskite cell. It should be understood that in other embodiments, the MPPT module (i.e., the first power point tracking module 35) can also be configured for the crystalline silicon cell, or the MPPT module can be configured only for the crystalline silicon cell.

[0153] (9) After the above steps, the output voltage is adjusted to the same. The first photovoltaic substring 21 and the second photovoltaic substring 22 can be directly connected in parallel and connected to the inverter. The inverter is also equipped with an MPPT module (i.e., the third power point tracking module). The output voltage of the two after being connected in parallel is equal to the first voltage of the first photovoltaic substring 21, and the current is the sum of the currents of the first photovoltaic substring 21 and the second photovoltaic substring 22, thereby eliminating the mismatch problem in the principle of the stacked components.

[0154] (10) An intelligent switch (i.e., the second protection device 36) can be optionally connected in series between the positive terminal of the first photovoltaic substring 21 and the first protection device 33 to achieve the purpose of selective shutdown. When the voltage and current detection indicates that the first photovoltaic substring 21 is abnormal or the overall power is too low, the second protection device 36 is disconnected. At this time, the power output of the photovoltaic string is completely provided by the second photovoltaic substring 22. The output voltage of the adjustment unit 32 no longer tracks the output voltage of the first photovoltaic substring 21, but is adjusted to the current tracking mode. The current amplitude can be set to a certain constant reference value, and the current of the entire string remains consistent.

[0155] In summary, this embodiment provides a new photovoltaic power generation system based on a stacked assembly. To address the mismatch problem caused by inconsistent output current and voltage of different photovoltaic sub-strings of the perovskite stacked assembly, the embodiment of the present application connects the power generation units at the same position of different stacked assemblies in series to form a string, that is, a photovoltaic sub-string (the number of strings is the number of different types of batteries). A regulation module is connected in series at the end of the string, and after the voltages between different photovoltaic sub-strings are adjusted to the same amplitude, they are connected in parallel to the DC input side of an inverter.

[0156] Specifically, for the four-terminal stacked components formed by crystalline silicon cells and perovskite cells, since the perovskite photovoltaic substrings and the crystalline silicon photovoltaic substrings independently undergo photovoltaic effects, different output voltages and currents are generated. If they are directly output in series and parallel, serious mismatch problems will occur, which will greatly reduce the output power. Since photovoltaic power generation is direct current, if chopping conversion (DC / DC) can be performed on independent photovoltaic substrings, the output voltages of the independent photovoltaic substrings can be unified, thereby eliminating the parallel mismatch caused by voltage inconsistency. Based on this, an embodiment of the present application provides a regulation module adapted to photovoltaic strings (such as photovoltaic stacked cells), which uses power electronics technology to perform voltage conversion on different photovoltaic substrings, unify the output voltages of different photovoltaic substrings in the photovoltaic string, eliminate parallel adaptation problems, and thus greatly improve the power generation efficiency of the stacked photovoltaic strings.

[0157] In another embodiment of the present application, a battery control method is provided, which is applied to the aforementioned photovoltaic string 20, wherein the photovoltaic string 20 includes a first photovoltaic sub-string 21 and a second photovoltaic sub-string connected in parallel, the first photovoltaic sub-string includes several first power generation units connected in series, and the second photovoltaic sub-string includes several second power generation units connected in series.

[0158] See Figure 13 , which is a flow chart of a battery control method provided in an embodiment of the present application.

[0159] like Figure 13 As shown, the method includes:

[0160] S61: Obtain a first voltage output by a first photovoltaic substring.

[0161] S62: performing voltage regulation processing on each of the second photovoltaic substrings based on the first voltage, so that the difference between the output voltage of each of the second photovoltaic substrings and the first voltage is less than or equal to a preset voltage threshold.

[0162] In the above process, the method further includes:

[0163] S63: Perform power point tracking on the first photovoltaic substring and / or the second photovoltaic substring, and adjust output parameters of the first photovoltaic substring and / or the second photovoltaic substring to keep them in a target power state.

[0164] It should be noted that step S63 has no sequential execution relationship with the aforementioned steps S61 and S62.

[0165] The above battery control method can be implemented via the aforementioned battery system 10. For a photovoltaic string consisting of a crystalline silicon string (i.e., the second photovoltaic sub-string) and a calcium silicate string (i.e., the first photovoltaic sub-string), see Figure 14 , the specific process of the battery control method is as follows:

[0166] S71: Start.

[0167] S72: Monitor the output voltage of the perovskite string.

[0168] S73: The Boost circuit of the crystalline silicon string is started.

[0169] S74: Adjust the output voltage of the crystalline silicon string to be the same as the output voltage of the perovskite string.

[0170] S75: The output voltage of the perovskite string and the output voltage of the crystalline silicon string are output in parallel.

[0171] S76: The MPPT module in the inverter performs power point tracking for real-time regulation.

[0172] The embodiments of the present application provide a power optimization strategy adapted for photovoltaic strings (e.g., photovoltaic stacked cells), which uses power electronics technology to perform voltage conversion on different photovoltaic sub-strings, unify the output voltages of different photovoltaic sub-strings in the photovoltaic string, eliminate parallel adaptation problems, and thus significantly improve the power generation efficiency of the stacked photovoltaic strings.

[0173] In another embodiment of the present application, a power generation device is provided, which includes at least the aforementioned battery system 10. Since the regulation module in the battery system 10 can adjust the output voltage of the second photovoltaic sub-string to be the same as the output voltage of the first photovoltaic sub-string, the mismatch between different photovoltaic sub-strings is eliminated, thereby improving the charging efficiency and battery life.

[0174] The above is only a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

[0175] It should be understood that the description of the above storage medium and device embodiments is similar to the description of the above method embodiments and has similar beneficial effects as the method embodiments. For technical details not disclosed in the storage medium, storage medium, and device embodiments of this application, please refer to the description of the method embodiments of this application for understanding.

[0176] It should be understood that "one embodiment" or "an embodiment" or "some embodiments" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" or "in some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The above-mentioned serial numbers of the embodiments of the present application are for description only and do not represent the advantages and disadvantages of the embodiments. The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other. For the sake of brevity, they will not be repeated here.

[0177] It should also be noted that, in this application, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0178] The serial numbers of the above embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0179] The methods disclosed in the several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0180] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0181] The features disclosed in the several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0182] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

[0183] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A battery system, characterized in that: The battery system includes a photovoltaic string and a regulation module; the photovoltaic string includes a first photovoltaic sub-string and a second photovoltaic sub-string connected in parallel; the first photovoltaic sub-string includes a plurality of first power generation units connected in series, and the second photovoltaic sub-string includes a plurality of second power generation units connected in series; The regulating module is connected to the first photovoltaic sub-string and the second photovoltaic sub-string, and is configured to obtain a first voltage output by the first photovoltaic sub-string; and perform voltage regulation on the second photovoltaic sub-string based on the first voltage so that the difference between the output voltage of the second photovoltaic string and the first voltage is less than or equal to a preset voltage threshold; The regulating module includes a control unit and a regulating unit, wherein the regulating unit is connected between the positive terminal, the negative terminal and the positive output terminal, the negative output terminal of the second photovoltaic substring; The control unit is configured to generate and output a first adjustment signal; The regulating unit is connected to the control unit and the second photovoltaic substring, and is configured to receive and, based on the first regulating signal, perform voltage regulation on the second photovoltaic substring so that a difference between an output voltage between a positive output terminal and a negative output terminal of the second photovoltaic substring and the first voltage is less than or equal to a preset voltage threshold.

2. The battery system according to claim 1, wherein: The control unit is connected to the first photovoltaic sub-string and the second photovoltaic sub-string; The control unit is specifically configured to control the duty cycle of the generated first adjustment signal based on the voltage difference between the second voltages between the positive terminal and the negative terminal of the second photovoltaic substring, and output the first adjustment signal.

3. The battery system according to claim 1, wherein: The regulating unit includes a boost chopper Boost circuit and / or a buck chopper Buck circuit; When the first voltage is greater than the second voltage of the second photovoltaic substring, the regulating unit is a boost chopper Boost circuit; In a case where the first voltage is less than the second voltage of the second photovoltaic substring, the regulating unit is a step-down chopper Buck circuit.

4. The battery system according to claim 3, characterized in that The Boost circuit is connected in series between the positive terminal / negative terminal of the second photovoltaic substring and the positive output end / negative output end of the second photovoltaic substring, and the control end of the Boost circuit receives the first regulation signal; or, The Buck circuit is connected in series between the positive terminal / negative terminal of the second photovoltaic substring and the positive output end / negative output end of the second photovoltaic substring, and the control end of the Buck circuit receives the first regulation signal.

5. The battery system according to any one of claims 1 to 4, characterized in that: The regulation module further includes a first power point tracking module, the first power point tracking module being connected to the positive terminal and the negative terminal of the first photovoltaic substring; The first power point tracking module is configured to track a target power point of the first photovoltaic substring and adjust an output parameter of the first photovoltaic substring based on a tracking result so as to keep the output parameter of the first photovoltaic substring at a target power state; The output parameter of the first photovoltaic substring after adjustment by the first power point tracking module includes the first voltage and / or the first current, and the first current refers to the current between the positive terminal and the negative terminal of the first photovoltaic substring.

6. The battery system according to any one of claims 1 to 4, characterized in that: The regulation module further includes a second power point tracking module; the second power point tracking module is connected to the positive terminal and the negative terminal of the second photovoltaic substring; The second power point tracking module is configured to track the target power point of the second photovoltaic substring and adjust the output parameters of the second photovoltaic substring based on the tracking result to keep the output parameters of the second photovoltaic substring at the target power state; The output parameter of the second photovoltaic substring after adjustment by the second power point tracking module includes a second voltage and / or a second current, and the second current refers to the current between the positive terminal and the negative terminal of the second photovoltaic substring.

7. The battery system according to any one of claims 1 to 4, characterized in that: The regulating module further includes a first protection device; The first protection device is connected in series between the positive terminal of the first photovoltaic substring and the positive output end of the first photovoltaic substring, and is configured to allow unidirectional current flow between the power generation unit in the first photovoltaic substring and the output end of the first photovoltaic substring.

8. The battery system according to any one of claims 1 to 4, characterized in that: The regulation module further includes a second protection device, which is connected in series between the positive terminal of the first photovoltaic substring and the positive output end of the first photovoltaic substring; The second protection device is configured to control the positive terminal of the first photovoltaic substring to be in a conductive state with the positive output end of the first photovoltaic substring if the output power of the first photovoltaic substring is greater than or equal to a preset threshold; If the output power of the first photovoltaic substring in the working state is less than a preset threshold, the positive connection terminal of the first photovoltaic substring and the positive output end of the first photovoltaic substring are controlled to be in an open circuit state.

9. The battery system according to any one of claims 1 to 4, characterized in that: The positive output end of the first photovoltaic sub-string and the positive output end of the second photovoltaic sub-string are connected in parallel to form the positive output end of the photovoltaic string group, and the negative output end of the first photovoltaic sub-string and the negative output end of the second photovoltaic sub-string are connected in parallel to form the negative output end of the photovoltaic string group; The battery system also includes an inverter; The inverter is connected to the positive output terminal and the negative output terminal of the photovoltaic string, and is configured to process the DC voltage output by the photovoltaic string to generate an AC voltage; wherein the inverter is configured with a third power point tracking module.

10. The battery system according to any one of claims 1 to 4, characterized in that: The first power generation unit and the second power generation unit are stacked to form a photovoltaic stacked cell, and the second power generation unit in the second photovoltaic substring has a different light absorption layer band gap from that of the first power generation unit; The photovoltaic string has an upper surface and a lower surface that are opposite to each other, and the first photovoltaic sub-string and the second photovoltaic sub-string are stacked between the upper surface and the lower surface.

11. A power generation device, characterized in that: The power generation device comprises the battery system according to any one of claims 1 to 10.

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