A battery assembly and photovoltaic system

Abstract

This invention relates to the field of photovoltaic technology and provides a battery module and a photovoltaic module. The battery module includes: a first battery string group and a second battery string group connected in series, the first battery string group including at least three battery strings connected in parallel, and the second battery string group including at least three battery strings connected in parallel; a diode connected in parallel with the first battery string group and the second battery string group; each battery string includes a plurality of battery cells connected in series, and each battery cell is a fragment of a whole battery cell, n ≥ 3. The use of multiple fragments greatly reduces internal losses and hot spot risk. Furthermore, the series and parallel connection of the first and second battery string groups makes it more compatible with the short-circuit voltage and open-circuit voltage of mainstream inverters and electrical systems, reducing system adaptation losses, lowering power losses, and increasing output power.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic technology, and particularly relates to a battery module and a photovoltaic system. Background Technology

[0002] In traditional photovoltaic module design, high-power modules using single-cell or two-cell batteries present significant systemic risks due to the large operating current of the cells. When multiple cells are connected in series and parallel, if the current in each string is inconsistent due to shading, dirt, or uneven aging, significant circulating currents will form at the parallel nodes, generating additional losses and accelerating local temperature rise. This can easily induce irreversible hot spot effects, directly affecting module lifespan and power plant safety. Furthermore, high current output places more stringent requirements on the current-carrying capacity of inverters, cables, and connectors. Improper matching can increase the risk of electrical system overload and cause additional line losses, posing a dual challenge to the overall system efficiency and reliability. Summary of the Invention

[0003] This invention provides a battery module and a photovoltaic system, which aims to solve the problems of traditional high-current modules in terms of internal circulating current, hot spot protection and system adaptation.

[0004] The present invention is implemented as follows: a battery assembly comprising: A first battery string group and a second battery string group are connected in series. The first battery string group includes at least three battery strings connected in parallel, and the second battery string group includes at least three battery strings connected in parallel. A diode is connected in parallel with the first battery string and the second battery string; The battery string includes several battery cells connected in series. Each battery cell is a split cell consisting of n segments, where n ≥ 3.

[0005] Optionally, the reverse bias voltage of the diode is greater than or equal to 90V.

[0006] Optionally, the battery cell is a three-cell structure.

[0007] Optionally, the number of the three-section cells in a battery string is 24 to 39.

[0008] Optionally, it also includes a busbar, which is disposed on the backlight surface of the first battery string group and the second battery string group. The busbar includes a first busbar, a second busbar and a third busbar. The positive terminal of the battery string in the first battery string group and the negative terminal of the battery string in the second battery string group are connected through the first busbar. The negative terminals of the battery strings in the first battery string group are connected via the second busbar; The positive terminals of the battery strings in the second battery string group are connected via the third busbar; The positive terminal of the diode is connected to the second busbar, and the negative terminal of the diode is connected to the third busbar.

[0009] Optionally, it may also include a first junction box, a second junction box, and a third junction box; The first junction box is provided with a cable electrical connection part. The box body of the first junction box is provided with a cable connection port on the side away from the second junction box. After the cable is connected and fixed to the cable electrical connection part, it is led out to one side from the cable connection port. The first junction box is not provided with the diode. The diode is installed inside the second junction box; The third junction box is provided with the cable electrical connection part, and the cable connection port is provided on the side of the third junction box away from the second junction box. After the cable is connected and fixed to the cable electrical connection part, it is led out to one side from the cable connection port. The third junction box is not provided with the diode.

[0010] Optionally, the battery strings in the first battery string group are arranged sequentially along the second direction, the battery strings in the second battery string group are arranged sequentially along the second direction, and the battery cells in a single battery string are arranged sequentially along the first direction, the second direction intersecting the first direction; The outer contour of the battery cell array is rectangular, and the rectangle has two long sides that are arranged opposite each other and extend along the first direction, and two short sides that are arranged opposite each other and extend along the second direction. The distance between any one of the first junction box, the second junction box, and the third junction box and the adjacent short side is 25mm to 150mm.

[0011] Optionally, the short side length is L, the center of the second junction box is located at L / 3 to (2 / 3)L, the first junction box and the third junction box are located on opposite sides of the second junction box, and the center of the first junction box and the center of the third junction box are at least L / 8 to L / 3 away from the adjacent long side.

[0012] Optionally, the first junction box and the second junction box are connected via the second busbar; The second junction box and the third junction box are connected by the third busbar.

[0013] Optionally, a first conductive module is provided in the first junction box, and the second busbar connection includes a first sub-busbar and a second sub-busbar, wherein the first sub-busbar is connected to one end of the first conductive module and the second sub-busbar is connected to the other end of the first conductive module.

[0014] Optionally, a second conductive module is provided in the third junction box, and the third busbar connection includes a third sub-busbar and a fourth sub-busbar. The third sub-busbar is connected to one end of the second conductive module, and the fourth sub-busbar is connected to the other end of the second conductive module.

[0015] Optionally, it also includes at least one fourth junction box, in which a third conductive module is disposed, and the first busbar connection includes at least two fifth sub-busbars, one of which is connected to one end of the third conductive module and the other of which is connected to the other end of the third conductive module.

[0016] Optionally, one fourth junction box is provided, and the fourth junction box is connected to two of the fifth sub-busbars.

[0017] Optionally, two fourth junction boxes are provided, and the two fourth junction boxes are connected to the three fifth sub-busbars.

[0018] The present invention also provides a photovoltaic system including the above-described battery module.

[0019] The beneficial effects achieved by this invention are that, due to the use of multi-segmentation, internal losses and hot spot risks are greatly reduced. The first battery string group includes at least three battery strings connected in parallel, and the second battery string group includes at least three battery strings connected in parallel. The first and second battery string groups are then connected in series, making them more compatible with the short-circuit and open-circuit voltages of mainstream inverters and electrical systems, reducing system adaptation losses, lowering power losses, and increasing output power. Attached Figure Description

[0020] Figure 1 This is a circuit connection diagram of the battery assembly provided by the present invention; Figure 2 This is a schematic diagram of the first structure of the battery assembly provided by the present invention; Figure 3 This is a schematic diagram of the second structure of the battery assembly provided by the present invention; Figure 4 This is a schematic diagram of the third structure of the battery assembly provided by the present invention.

[0021] Explanation of reference numerals in the attached figures: 100. Battery assembly; 110. First battery string group; 120. Second battery string group; 101. Battery string; 1011. Battery cell; 130. Diode; 140. First busbar; 141. Fifth sub-busbar; 150. Second busbar; 151. First sub-busbar; 152. Second sub-busbar; 160. Third busbar; 161. Third sub-busbar; 162. Fourth sub-busbar; 171. First junction box; 172. Second junction box; 173. Third junction box; 180. Fourth junction box. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the invention, and should not be construed as limiting the invention. Furthermore, it should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0028] This invention, by employing a multi-segment design, significantly reduces internal losses and the risk of hot spots. The first battery string group comprises at least three battery strings connected in parallel, and the second battery string group comprises at least three battery strings connected in parallel. The first and second battery string groups are then connected in series, making them more compatible with the short-circuit and open-circuit voltages of mainstream inverters and electrical systems, reducing system adaptation losses, lowering power losses, and increasing output power.

[0029] Example 1 like Figure 1 As shown, this embodiment provides a battery assembly 100, including: a first battery string group 110 and a second battery string group 120 connected in series. The first battery string group 110 includes at least three battery strings 101 connected in parallel, and the second battery string group 120 includes at least three battery strings 101 connected in parallel. Diode 130 is connected in parallel with the first battery string group 110 and the second battery string group 120; The battery string 101 includes several battery cells 1011 connected in series. Each battery cell 1011 is an n-segmented piece after the whole battery cell 1011 has been split, where n ≥ 3.

[0030] In the photovoltaic industry, a 1011 whole-cell solar cell typically refers to a standardized solar cell cut from a semiconductor silicon ingot (monocrystalline or polycrystalline) without any lateral physical cutting. It represents the final form from silicon wafer to finished cell, with its surface covered by fine grid lines for collecting current, and its overall structure undivided by subsequent processing. As the photovoltaic industry has undergone continuous upgrades in silicon wafer size, the size of whole-cell cells has also become standardized. Currently, the mainstream sizes include: M10, a cell made from a quasi-square silicon wafer with a side length of approximately 182mm; and G12, a cell made from a quasi-square silicon wafer with a side length of approximately 210mm.

[0031] The solar cell 1011 in this application is made by laser-cutting a standard-sized complete solar cell (the whole solar cell 1011) into n (n≥3) narrower solar cell pieces along the extension direction of the fine grid lines. For example, a three-piece solar cell 1011 is cut into 3 pieces, usually in thirds, with each third piece being 1 / 3 of the whole solar cell 1011; a four-piece solar cell 1011 is cut into 4 pieces, usually in fourths, with each quarter piece being 1 / 4 of the whole solar cell 1011, and so on. After cutting, the operating current of each small piece (piece) is approximately reduced to 1 / n of the whole piece, while the operating voltage remains essentially unchanged. Specifically, the solar cell 1011 can be a back-contact solar cell.

[0032] Several battery cells 1011 are connected in series using solder ribbons to form a "battery string 101". At least three such battery strings 101 are connected in parallel to form a first battery string group 110; then at least three such battery strings 101 are connected in parallel to form a second battery string group 120. Connecting the first battery string group 110 and the second battery string group 120 in series can increase the output voltage of the entire module, bringing it to a range suitable for inverter operation.

[0033] A diode 130 is connected in parallel with the entire series connection of the first battery string 110 and the second battery string 120. This diode 130 is commonly referred to as a bypass diode, and its function is to provide a "bypass" for current when the component is partially blocked or fails, preventing the blocked battery string 101 from overheating and being damaged due to power consumption (hot spot effect), and minimizing the impact of the fault on the overall power output.

[0034] In traditional high-power modules using single-cell or two-cell modules, the cell itself has a large current. When multiple cell strings (101) are connected in parallel, if the current of each string is inconsistent due to shading, dirt, uneven aging, etc., significant circulating current losses will occur at the parallel connection nodes, and even serious hot spots may be caused. After adopting three-cell modules, the current of a single cell string (101) is reduced to about 1 / 3 of the original. When connected in parallel, even if there are current differences between the strings, the absolute value of the circulating current is greatly reduced, thereby greatly reducing internal losses and the risk of hot spots, and improving the long-term reliability and safety of the module.

[0035] In a photovoltaic power station system, the output current of the modules needs to match the maximum input current range of the inverter, as well as the current carrying capacity of the cables and connectors. The first battery string group 110 includes at least three battery strings 101 connected in parallel, and the second battery string group 120 includes at least three battery strings 101 connected in parallel. The first battery string group 110 and the second battery string group 120 are then connected in series to better match the short-circuit voltage and open-circuit voltage of mainstream inverters and electrical systems, reducing system adaptation losses, lowering power losses, and increasing output power.

[0036] In some embodiments, the reverse bias voltage of diode 130 is greater than or equal to 90V. Diode 130 is used as a bypass diode in the circuit. Under normal operating conditions, the voltage generated by the module causes diode 130 to be reverse biased (i.e., the anode potential is lower than the cathode), diode 130 is cut off, equivalent to being open, and all current flows through battery string 101. When the module is partially shaded or a battery string 101 fails, diode 130 needs to conduct to provide a bypass for the current. At this time, all the voltage generated by the healthy battery string 101 will be applied across diode 130, which is in a reverse bias state.

[0037] The reverse bias voltage of diode 130 is the voltage applied between its terminals, which puts it in a "reverse cutoff" state. In other words, within this voltage range, diode 130 is in a cutoff state. Similar to a safety margin, it ensures that diode 130 will not break down in actual circuits (especially in systems with high voltage like photovoltaic strings), even under the most severe potential differences, thus guaranteeing the module's decades-long lifespan.

[0038] The module consists of two series-connected battery string groups 101 (first battery string group 110 and second battery string group 120). Each battery string group 101 is composed of battery cells 1011 connected in series, and its open-circuit voltage design value is typically within the system's safe voltage range. The diode 130 is connected in parallel across the entire series connection, therefore it needs to withstand the open-circuit voltage of a complete module. The reverse bias voltage of diode 130 is greater than or equal to 90V, ensuring that the bypass diode can operate stably and reliably in the photovoltaic system and will not fail due to excessive voltage.

[0039] In some embodiments, the solar cell 1011 is divided into three segments. A segment is essentially a whole solar cell 1011 cut into three elongated segments of equal area. After cutting, each segment remains an independent and complete functional unit. The area and current of a single cell in a segment are reduced. When one segment is blocked, the heat generated is less and more dispersed, further diverting and limiting the heat from hot spots. This significantly reduces the risk of module failure due to hot spots and improves the reliability for long-term outdoor use.

[0040] Furthermore, the number of cells in a string of 101 cells is 24 to 39. The number of cells 1011 determines the open-circuit voltage of the module, that is, the terminal voltage of the module when it is unloaded under standard test conditions. When the number of cells in a string of 101 cells is 24 to 39, the open-circuit voltage of the resulting module can be adapted to the system voltage of large power plants.

[0041] In some embodiments, such as Figures 2 to 3 As shown, the battery assembly 100 also includes a busbar, which is disposed on the backlight surface of the first battery string group 110 and the second battery string group 120. The busbar includes a first busbar 140, a second busbar 150 and a third busbar 160. The positive terminal of the battery string 101 in the first battery string group 110 is connected to the negative terminal of the battery string 101 in the second battery string group 120 through the first busbar 140; the negative terminal of the battery string 101 in the first battery string group 110 is connected through the second busbar 150; the positive terminal of the battery string 101 in the second battery string group 120 is connected through the third busbar 160; the positive terminal of the diode 130 is connected to the second busbar 150, and the negative terminal of the diode 130 is connected to the third busbar 160.

[0042] A solar cell has two main sides: a light-facing side and a back-facing side. The light-facing side faces the sunlight directly, while the back-facing side is on the opposite side; the two sides are positioned opposite each other. The busbar is located on the back-facing side and does not obstruct the light-facing side.

[0043] The second busbar 150 is the common negative busbar for the first battery string group 110, and the negative terminals of all battery strings 101 within the first group are connected to the second busbar 150. The third busbar 160 is the common positive busbar for the second battery string group 120, and the positive terminals of all battery strings 101 within the second group are connected to the third busbar 160. The first busbar 140 is the connection point between the positive terminals of the first battery string group 110 and the negative terminals of the second battery string group 120, where all the positive terminals of the first group and all the negative terminals of the second group converge. The positive terminal of the entire assembly is led out from the third busbar 160, and the negative terminal is led out from the second busbar 150. The anode of diode 130 is connected to the second busbar 150, and the cathode of diode 130 is connected to the third busbar 160. When all cell strings 101 of the module are operating normally, for diode 130, its anode potential (second busbar 150) is the lowest potential of the module, and its cathode potential (third busbar 160) is the highest potential of the module. The anode voltage of diode 130 is much lower than its cathode voltage, and diode 130 is in a reverse bias state, equivalent to an open circuit. This has no impact on the power generation circuit, and all current flows through the two cell strings 101.

[0044] Specifically, the battery strings 101 in the first battery string group 110 are arranged sequentially along the second direction, the battery strings 101 in the second battery string group 120 are arranged sequentially along the second direction, and the battery cells 1011 in a single battery string 101 are arranged sequentially along the first direction. The second direction intersects with the first direction, and usually the second direction is perpendicular to the first direction. Figures 2 to 4 As shown, the first battery string group 110 includes three battery strings 101, which are respectively placed in the first, second, and third rows; the second battery string group 120 includes three battery strings 101, which are respectively placed in the fourth, fifth, and sixth rows. The positive terminal orientation of the battery strings 101 in the first battery string group 110 is opposite to that of the battery strings 101 in the second battery string group 120. Thus, the first busbar 140, the second busbar 150, and the third busbar 160 all extend along the second direction, resulting in a clear busbar layout suitable for automated welding and lamination processes, representing an industrial standard design.

[0045] Furthermore, the battery assembly 100 also includes a first junction box 171, a second junction box 172, and a third junction box 173; the first junction box 171 is provided with a cable connection part, and the side of the first junction box 171 away from the second junction box 172 is provided with a cable connection port. After the cable is connected and fixed to the cable connection part, it is led out to one side from the cable connection port. The first junction box 171 does not have a diode 130; the second junction box 172 has a diode 130; the third junction box 173 is provided with a cable connection part, and the side of the third junction box 173 away from the second junction box 172 is provided with a cable connection port. After the cable is connected and fixed to the cable connection part, it is led out to one side from the cable connection port. The third junction box 173 does not have a diode 130.

[0046] Neither the first junction box 171 nor the second junction box 172 contains diodes 130; they only have cable connection sections, serving as the negative and positive terminals for the modules, respectively, responsible for electrical connection and mechanical fixation of the cables. The second junction box 172, located between the first and second junction boxes 171 and 172, contains diodes 130 for module hotspot protection. The positive and negative output cables are independently led out from the first junction box 171 and the third junction box 173 at both ends, with a relatively long distance between them. This significantly shortens the cable routing length on the back of the module compared to traditional designs that draw all cables from a single box. Shorter cable paths mean lower resistance, slightly improving system efficiency. Simultaneously, it reduces the amount of cable used inside the modules and during array installation. In photovoltaic arrays, cables between modules can be connected at the nearest point, reducing bridging and making wiring more organized.

[0047] Specifically, both the first junction box 171 and the third junction box 173 are equipped with cable connection ports. Cables are led out from the cable connection ports. The cable connection ports on the first junction box 171 and the third junction box 173 are arranged opposite each other, each facing the direction of the second junction box 172. This helps to shorten the cable length.

[0048] Furthermore, the battery cells 1011 within the battery assembly 100 are arranged in an array, and the outer contour of the battery cell array is rectangular, having two long sides arranged opposite to each other and extending along a first direction, and two short sides arranged opposite to each other and extending along a second direction. A single battery string 101 includes several battery cells 1011 arranged along a first direction, and several battery strings 101 are arranged along a second direction. The number of battery cells 1011 in a single battery string 101 is a fixed value, and the area of ​​a single battery cell 1011 is also a fixed value. All battery cells 1011 are arranged in an array to form a rectangle. Two of the four sides of this rectangle extend along the first direction and are the long sides, while the other two sides extend along the second direction and are the short sides.

[0049] The first junction box 171, the second junction box 172, and the third junction box 173 are all installed on the back of the module. The vertical distance from the outer edge of the first junction box 171, the second junction box 172, or the third junction box 173 to the nearest short side is controlled within the range of 25mm to 150mm. The lower limit of 25mm ensures sufficient distance from the inner wall of the aluminum frame, allowing space for frame bending and sealant filling. This prevents the junction box from protruding too much and colliding with the frame or bracket of adjacent modules when the modules are closely arranged. The upper limit of 150mm prevents the junction box from extending too far into the module, encroaching on the valuable effective power generation area of ​​the 1011 solar cells. This ensures that it remains in a relatively rigid area at the edge of the module, preventing the junction box from cracking or failing to seal due to excessive bending in the middle of the module during transportation and installation stress, complying with the limitation requirements for the position of back protrusions in most mainstream bracket systems.

[0050] Furthermore, the shorter side is L. The center of the second junction box 172 is located at L / 3 to (2 / 3)L. The first junction box 171 and the third junction box 173 are located on opposite sides of the second junction box 172. The center of the first junction box 171 and the center of the third junction box 173 are at least L / 8 to L / 3 away from their adjacent longer sides. It should be noted that the orthographic projection of the junction box is a rectangle, and the intersection of the diagonals of the rectangle is the center. The center of the second junction box 172 is located at L / 3 to (2 / 3)L. The first junction box 171 and the third junction box 173 are located on opposite sides of the second junction box 172. The first junction box 171 is located at L / 8 to L / 3 on one side, that is, the first junction box 171 is located at L / 8 to L / 3 away from its adjacent longer side. The third junction box 173 is located at L / 8 to L / 3 on the other side, that is, the third junction box 173 is located at L / 8 to L / 3 away from its adjacent longer side. The first junction box 171 and the third junction box 173 can be symmetrically distributed with respect to the midpoint or asymmetrically distributed. For example, the first junction box 171 is located at L / n, and the third junction box 173 is located at L / m. This can be either n=m or n≠m.

[0051] In some embodiments, both the second busbar 150 and the third busbar 160 extend along a second direction. The first junction box 171 and the second junction box 172 are connected via the second busbar 150; the second junction box 172 and the third junction box 173 are connected via the third busbar 160. That is, the positive terminal of the second junction box 172 is connected to the second busbar 150, and the negative terminal of the second junction box 172 is connected to the third busbar 160. The first junction box 171 is disposed on the second busbar 150, and the third junction box 173 is disposed on the third busbar 160. The second junction box 172 is located at L / 2, meaning that the total length of the second busbar 150 and the total length of the third busbar 160 are equal.

[0052] Furthermore, a first conductive module is provided inside the first junction box 171, and a second busbar 150 connects a first sub-busbar 151 and a second sub-busbar 152. The first sub-busbar 151 is connected to one end of the first conductive module, and the second sub-busbar 152 is connected to the other end of the first conductive module.

[0053] The first conductive module is an independent conductive component located inside the first junction box 171. It may be a metal bridging piece, a conductive bus, or a connector with a specific structure. Its core function is to act as a bridge for conducting circuits, connecting the first sub-busbar 151 and the second sub-busbar 152 to their respective ends. The first sub-busbar 151 and the second sub-busbar 152 are electrically connected through the first conductive module. The first sub-busbar 151 and the second sub-busbar 152, as two segments of the second busbar 150, have a shorter length than the entire second busbar 150. A shorter conductor results in less absolute deformation due to thermal expansion and contraction, leading to less stress at the connection points. During vibration, the shorter conductor inherently has a higher resonant frequency, making it less prone to coupling with the overall vibration frequency of the component, thus providing better vibration resistance.

[0054] Furthermore, a second conductive module is provided inside the third junction box 173, and the third busbar 160 connects a third sub-busbar 161 and a fourth sub-busbar 162. The third sub-busbar 161 is connected to one end of the second conductive module, and the fourth sub-busbar 162 is connected to the other end of the second conductive module.

[0055] The second conductive module is an independent conductive component located inside the first junction box 171. It may be a metal bridging piece, a conductive bus, or a connector with a specific structure. Its core function is to act as a bridge for conducting circuits, connecting the third sub-busbar 161 and the fourth sub-busbar 162 to their respective ends. The third sub-busbar 161 and the fourth sub-busbar 162 are electrically connected through the second conductive module. As two segments of the second busbar 150, the third sub-busbar 161 and the fourth sub-busbar 162 are shorter than the entire second busbar 150. Shorter conductors exhibit less absolute deformation due to thermal expansion and contraction, resulting in less stress at the connection points. During vibration, the shorter conductor inherently has a higher resonant frequency, making it less prone to coupling with the overall vibration frequency of the component, thus providing better vibration resistance.

[0056] Understandably, one end of the third sub-busbar 161 is electrically connected to the second conductive module, and the other end is connected to one end of the diode 130 in the second wiring. One end of the second sub-busbar 152 is electrically connected to the first conductive module, and the other end is connected to the other end of the diode 130. Normally, the diode 130 is biased.

[0057] In some embodiments, such as Figure 3 and Figure 4 As shown, it also includes a fourth junction box 180, in which a third conductive module is disposed. The second busbar 150 is connected to at least two fifth sub-busbars 141, one fifth sub-busbar 141 is connected to one end of the third conductive module, and the other fifth sub-busbar 141 is connected to the other end of the third conductive module.

[0058] The third conductive module is an independent conductive component located inside the first junction box 171. It may be a metal bridging piece, a conductive bus, or a connector with a specific structure. Its core function is to act as a bridge for conducting circuits, connecting the two fifth sub-busbars 141 to their respective ends. The two fifth sub-busbars 141 are electrically connected through the third conductive module. As at least two segments of the second busbar 150, the fifth sub-busbars 141 are shorter in length than the entire second busbar 150. Shorter conductors exhibit less absolute deformation due to thermal expansion and contraction, resulting in less stress at the connection points. During vibration, the shorter conductor inherently has a higher resonant frequency, making it less prone to coupling with the overall vibration frequency of the component, thus providing better vibration resistance.

[0059] Specifically, such as Figure 3 As shown, when there is only one fourth junction box 180, there are two fifth sub-busbars 141. The two fifth sub-busbars 141 are connected to the two ends of the fourth junction box 180 respectively. Figure 4 As shown, when there are two fourth junction boxes 180, there are three fifth sub-busbars 141. The two ends of one fifth sub-busbar 141 are connected to one end of the two fourth junction boxes 180 respectively, and the other ends of the two fourth junction boxes 180 are connected to one fifth sub-busbar 141 respectively.

[0060] It should be noted that, usually for ease of manufacturing, the length of each fifth sub-busbar 141 is equal. The length of the short side is L. When there is one fourth junction box 180, the fourth junction box 180 is located at L / 2. When there are two fourth junction boxes 180, the fourth junction boxes 180 are located at L / 3 and L (2 / 3) respectively.

[0061] The battery module 100 may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulant film (not shown in the figures). The encapsulant film can be filled between the light-facing side of the solar cell and the photovoltaic glass, the back-facing side and the backsheet, and adjacent cells 1011, etc. As a filler, it can be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulant film can be EVA film or POE film, and the specific choice can be made according to the actual situation, without limitation.

[0062] Photovoltaic glass can be applied to the encapsulating film on the light-facing side of a solar cell. This photovoltaic glass can be ultra-clear glass, possessing high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, ultra-clear glass can achieve a light transmittance of over 92%, protecting the solar cell while minimizing impact on its efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the solar cell together, providing sealing, insulation, and waterproofing / moisture protection for the solar cell.

[0063] The backsheet can be attached to the encapsulant film on the back side of the solar cell. The backsheet protects and supports the solar cell, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, and aluminum alloy TPT composite encapsulant film, etc. The specific choice depends on the specific circumstances and is not limited here. The backsheet, solar cell, encapsulant film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire battery module 100, providing stable support and installation. For example, the battery module 100 can be installed at the desired location using the metal frame.

[0064] The beneficial effects of the battery module 100 in this embodiment are equivalent to those of the solar cell described above, and will not be repeated here.

[0065] Example 2 This embodiment provides a photovoltaic system, including the aforementioned battery module 100.

[0066] Photovoltaic systems can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. They can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it's understandable that the application scenarios of photovoltaic systems are not limited to these; that is, photovoltaic systems can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system grid as an example, a photovoltaic system can include photovoltaic arrays, combiner boxes, and inverters. The photovoltaic array can be an array combination of multiple battery modules 100. For example, multiple battery modules 100 can form multiple photovoltaic arrays. The photovoltaic arrays are connected to combiner boxes, which can collect the current generated by the photovoltaic arrays. The collected current flows through an inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0067] The beneficial effects of the photovoltaic system in this embodiment are equivalent to the beneficial effects of the battery module 100 described above, and will not be repeated here.

[0068] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A battery assembly, characterized in that, include: A first battery string group and a second battery string group are connected in series. The first battery string group includes at least three battery strings connected in parallel, and the second battery string group includes at least three battery strings connected in parallel. A diode is connected in parallel with the first battery string and the second battery string; The battery string includes several battery cells connected in series. Each battery cell is a split cell consisting of n segments, where n ≥ 3.

2. The battery assembly as claimed in claim 1, characterized in that, The reverse bias voltage of the diode is greater than or equal to 90V.

3. The battery assembly as described in claim 1, characterized in that, The battery cells are divided into three sections.

4. The battery assembly as described in claim 3, characterized in that, The number of the three-section cells in a battery string is 24 to 39.

5. The battery assembly as claimed in claim 1, characterized in that, It also includes a busbar, which is disposed on the backlight surface of the first battery string group and the second battery string group. The busbar includes a first busbar, a second busbar and a third busbar. The positive terminal of the battery string in the first battery string group and the negative terminal of the battery string in the second battery string group are connected through the first busbar. The negative terminals of the battery strings in the first battery string group are connected via the second busbar; The positive terminals of the battery strings in the second battery string group are connected via the third busbar; The positive terminal of the diode is connected to the second busbar, and the negative terminal of the diode is connected to the third busbar.

6. The battery assembly as claimed in claim 5, characterized in that, It also includes a first junction box, a second junction box, and a third junction box; The first junction box is provided with a cable electrical connection part. The side of the first junction box body away from the second junction box is provided with a cable connection port. After the cable is connected and fixed to the cable electrical connection part, it is led out to one side from the cable connection port. The first junction box is not provided with the diode. The diode is installed inside the second junction box; The third junction box is provided with the cable electrical connection part, and the cable connection port is provided on the side of the third junction box away from the second junction box. After the cable is connected and fixed to the cable electrical connection part, it is led out to one side from the cable connection port. The third junction box is not provided with the diode.

7. The battery assembly as claimed in claim 6, characterized in that, The battery strings in the first battery string group are arranged sequentially along the second direction, the battery strings in the second battery string group are arranged sequentially along the second direction, and the battery cells in a single battery string are arranged sequentially along the first direction, the second direction intersecting the first direction; The outer contour of the battery cell array is rectangular, and the rectangle has two long sides that are arranged opposite each other and extend along the first direction, and two short sides that are arranged opposite each other and extend along the second direction. The distance between any one of the first junction box, the second junction box, and the third junction box and the adjacent short side is 25mm to 150mm.

8. The battery assembly as claimed in claim 7, characterized in that, The short side has a length of L. The center of the second junction box is located at L / 3 to (2 / 3)L. The first junction box and the third junction box are located on opposite sides of the second junction box. The center of the first junction box and the center of the third junction box are at least L / 8 to L / 3 away from the adjacent long side.

9. The battery assembly as claimed in claim 6, characterized in that, The first junction box and the second junction box are connected by the second busbar; The second junction box and the third junction box are connected by the third busbar.

10. The battery assembly as claimed in claim 9, characterized in that, The first junction box contains a first conductive module, and the second busbar connection includes a first sub-busbar and a second sub-busbar. The first sub-busbar is connected to one end of the first conductive module, and the second sub-busbar is connected to the other end of the first conductive module.

11. The battery assembly as claimed in claim 9, characterized in that, The third junction box is equipped with a second conductive module. The third busbar connection includes a third sub-busbar and a fourth sub-busbar. The third sub-busbar is connected to one end of the second conductive module, and the fourth sub-busbar is connected to the other end of the second conductive module.

12. The battery assembly as claimed in claim 5, characterized in that, It also includes at least one fourth junction box, in which a third conductive module is disposed. The first busbar includes at least two fifth sub-busbars, one of which is connected to one end of the third conductive module and the other of which is connected to the other end of the third conductive module.

13. The battery assembly as claimed in claim 12, characterized in that, One fourth junction box is provided, and the fourth junction box is connected to two of the fifth sub-busbars.

14. The battery assembly as claimed in claim 12, characterized in that, Two fourth junction boxes are provided, and the two fourth junction boxes are connected to the three fifth sub-busbars.

15. A photovoltaic system, characterized in that, Includes the battery assembly described in any one of claims 1-14.

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