Battery system, control method of battery system, and energy storage battery

Abstract

The application discloses a battery system, a control method of the battery system and an energy storage battery, and relates to the technical field of battery systems. The battery system comprises a battery circuit, a switching circuit and a controller. The battery circuit comprises at least two battery packs. The first end of the switching circuit is connected with the battery circuit, the second end of the switching circuit is used for connecting an external system, and the switching circuit has a parallel mode and a series mode. In the parallel mode, the at least two battery packs are connected in parallel. In the series mode, the at least two battery packs are connected in series. The controller is connected with the switching circuit and is used for: when a voltage signal is detected at the second end of the switching circuit, controlling the switching circuit to switch to the parallel mode or the series mode according to the voltage signal; or when no voltage signal is detected at the second end of the switching circuit, first controlling the switching circuit to switch to a first mode to start the external system, and when the external system fails to start, controlling the switching circuit to switch to a second mode. The above scheme can start the external system to work by performing series-parallel switching.

Description

Technical Field

[0001] This application relates to the field of battery management, and in particular to a battery system, a control method for the battery system, and an energy storage battery. Background Technology

[0002] Currently, energy storage systems employ two completely independent battery pack designs for single-phase and three-phase systems. The 400V battery pack is dedicated to single-phase energy storage systems, such as residential energy storage; the 800V battery pack is dedicated to three-phase energy storage systems, such as industrial and commercial energy storage. The two battery packs differ in hardware design, software code, and battery management system (BMS) management strategies. Therefore, appropriate management of these two battery packs is urgently needed for their effective use. Summary of the Invention

[0003] This application provides at least one battery system, a control method for the battery system, and an energy storage battery to solve the above-mentioned problems.

[0004] This application provides a battery system comprising: a battery circuit including at least two battery packs; a switching circuit having a first terminal connected to the battery circuit and a second terminal for connecting to an external system, and having a parallel mode and a series mode, wherein the parallel mode is configured to connect the at least two battery packs in parallel, and the series mode is configured to connect the at least two battery packs in series; and a controller connected to the switching circuit, configured to: when a voltage signal is detected at the second terminal of the switching circuit, control the switching circuit to switch to the parallel mode or the series mode according to the voltage signal; or, when a voltage signal is detected at the second terminal of the switching circuit, first control the switching circuit to switch to a first mode to start the external system, and when the external system fails to start, control the switching circuit to switch to a second mode; wherein the first mode is one of the parallel mode and the series mode, and the second mode is the other.

[0005] In some embodiments, controlling the switching circuit to switch to the parallel mode or the series mode according to the voltage signal includes: when the amplitude of the voltage signal is within a first voltage range, the controller controls the switching circuit to switch to the parallel mode; when the amplitude of the voltage signal is within a second voltage range, the controller controls the switching circuit to switch to the series mode, wherein the minimum value of the second voltage range is greater than the maximum value of the first voltage range.

[0006] In some embodiments, the step of controlling the switching circuit to switch to a first mode to start the external system when no voltage signal is detected at the second terminal of the switching circuit, and controlling the switching circuit to switch to a second mode when the external system fails to start, includes: controlling the switching circuit to switch to the parallel mode to start the external system when no voltage signal is detected at the second terminal of the switching circuit, and controlling the switching circuit to switch to the series mode when the external system fails to start.

[0007] In some embodiments, after the switching circuit switches to the parallel mode or the series mode, the controller is further configured to: detect the output voltage of the at least two battery packs and the output voltage of the second terminal of the switching circuit, respectively, to determine whether the output voltage of the at least two battery packs through the switching circuit matches the external system.

[0008] In some embodiments, determining whether the output voltage of the at least two battery packs through the switching circuit matches the external system includes: in the parallel mode, if the output voltage of the second terminal of the switching circuit is the same as the output voltage of each battery pack, then determining that the output voltage of the at least two battery packs through the switching circuit matches the external system; or, in the series mode, if the output voltage of the second terminal of the switching circuit is the sum of the output voltages of each battery pack, then determining that the output voltage of the at least two battery packs through the switching circuit matches the external system.

[0009] In some embodiments, when it is determined that the output voltage of the at least two battery packs through the switching circuit does not match the external system, the controller is further configured to: send an alarm signal; and / or disable the output of the battery circuit.

[0010] In some embodiments, the switching circuit includes a first switching element and a second switching element. The first switching element has a first set of ends for connection to the positive terminals of the at least two battery packs and a second set of ends for connection to the negative terminals of the second terminal of the switching circuit. The second switching element has a first set of ends for connection to the negative terminals of the at least two battery packs and a second set of ends for connection to the positive terminals of the second terminal of the switching circuit. The first switching element and the second switching element cooperate to switch between the parallel mode and the series mode.

[0011] In some embodiments, the controller is configured to, before the external system fails to start, include at least one of the following: receiving a voltage alarm signal from the external system; or, not receiving a startup success signal from the external system within a preset time period.

[0012] In some embodiments, the controller is further configured to: when a voltage signal is detected at the second terminal of the switching circuit, the battery system is in a grid-connected state; or, when a voltage signal is not detected at the second terminal of the switching circuit, the battery system is in an off-grid state.

[0013] A second aspect of this application provides a control method for a battery system, applied to a controller in the battery system. The battery system includes a battery circuit, a switching circuit, and a controller. The switching circuit has a parallel mode and a series mode. In the parallel mode, at least two battery packs of the battery circuit are connected in parallel, and in the series mode, the at least two battery packs are connected in series. The method includes: detecting whether a voltage signal exists at the output terminal of the switching circuit used to connect to an external system; if the voltage signal exists, controlling the switching circuit to switch to the parallel mode or the series mode according to the voltage signal; if the voltage signal does not exist, first controlling the switching circuit to switch to a first mode to start the external system; if the external system fails to start, controlling the switching circuit to switch to a second mode, wherein the first mode is one of the parallel mode and the series mode, and the second mode is the other.

[0014] A third aspect of this application provides an energy storage battery, the energy storage battery including an inverter and a battery system as described in the first aspect, wherein the inverter is connected as a second terminal of a switching circuit in the external system and the battery system.

[0015] The beneficial effects of this application are as follows: The battery system includes a battery circuit, a switching circuit, and a controller. The battery circuit includes at least two battery packs; the switching circuit has a first terminal connected to the battery circuit and a second terminal for connecting to an external system, and has parallel and series modes, wherein the parallel mode is configured to connect at least two battery packs in parallel, and the series mode is configured to connect at least two battery packs in series; the controller is connected to the switching circuit and is used to: when a voltage signal is detected at the second terminal of the switching circuit, control the switching circuit to switch to either parallel or series mode based on the voltage signal; or, when no voltage signal is detected at the second terminal of the switching circuit, first control the switching circuit to switch to the first mode to start the external system, and if the external system fails to start, control the switching circuit to switch to the second mode. This enables the battery system to start the external system in both grid-connected and off-grid scenarios through series-parallel switching, saving the cost of code development, testing, and maintenance, and reducing the complexity of software management.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this application. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with this application and, together with the specification, serve to explain the technical solutions of this application.

[0018] Figure 1 This is a schematic diagram of the battery system according to an embodiment of this application; Figure 2 This is a partial circuit diagram of the battery system according to an embodiment of this application; Figure 3 This is a schematic flowchart of the control method of the battery system according to an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the energy storage battery according to an embodiment of this application; Detailed Implementation In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0019] In this document, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects are in an "or" relationship. Furthermore, "many" in this document means two or more. Additionally, the term "at least one" in this document means any combination of at least two of any one or more of a plurality of objects. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C. Furthermore, the terms "first," "second," and "third" in this application are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0020] As mentioned above, current energy storage systems employ two independent battery pack designs for single-phase and three-phase systems. This necessitates maintaining two separate sets of software code for system management, increasing the workload and cost of code development, testing, and maintenance. Furthermore, the hardware platform of current energy storage systems cannot be unified, requiring the design and production of two different battery packs, increasing product development cycles and production complexity. Because single-phase and three-phase energy storage systems use different types of battery packs, separate 400V and 800V battery packs need to be stocked, increasing inventory costs and capital tied up. The variety of spare parts also increases after-sales service costs and complexity. On the other hand, users cannot flexibly upgrade after purchasing the product; that is, users who have purchased a single-phase energy storage system cannot upgrade to a three-phase system.

[0021] Therefore, this application provides a battery system, a control method for the battery system, and an energy storage battery to solve the above problems.

[0022] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Please see Figure 1 , Figure 1 This is a schematic diagram of the battery system according to an embodiment of this application. The battery system 100 includes a battery circuit 110, a switching circuit 120, and a controller 130. The battery circuit 110 includes at least two battery packs 111. The switching circuit 120 has a first terminal connected to the battery circuit 110 and a second terminal for connecting to an external system 200, and has a parallel mode and a series mode. The parallel mode is configured to connect at least two battery packs 111 in parallel, and the series mode is configured to connect at least two battery packs 111 in series. The controller 130 is connected to the switching circuit 120 and is used to: when a voltage signal is detected at the second terminal of the switching circuit 120, control the switching circuit 120 to switch to either the parallel mode or the series mode based on the voltage signal; or, when no voltage signal is detected at the second terminal of the switching circuit 120, first control the switching circuit 120 to switch to the first mode to start the external system 200, and if the external system 200 fails to start, control the switching circuit 120 to switch to the second mode; wherein the first mode is one of the parallel mode and the series mode, and the second mode is the other.

[0024] Battery system 100 refers to an electronic device that integrates necessary functional units such as battery, electronic control, thermal management, structural protection, and safety protection, and is capable of storing, releasing, and managing electrical energy. Battery circuit 110 refers to an electronic circuit used to realize electrical energy storage and power regulation. Switching circuit 120 refers to an electronic circuit used to change the connection state of the power path according to preset logic or external instructions to realize the switching of operating modes. Controller 130 refers to a control management unit used to receive input signals, perform logical operations, and output control commands to realize the state monitoring, decision processing, and coordinated management of battery system 100.

[0025] like Figure 2 As shown, the battery circuit 110 may include at least two battery packs 111, the number of which is set according to the specific application scenario. The at least two battery packs 111 can output different voltages, such as 200V, 400V, 600V, 800V, etc. Here, battery pack 111 refers to an energy storage power supply device used to realize energy storage and stably output electrical energy. Battery pack 111 may include a DC-DC converter 112 and a battery. The DC-DC converter 112 is connected to the battery. The battery refers to an energy storage module in battery pack 111 that can be independently assembled, stably supply power, and has protection and management functions. The DC-DC converter 112 refers to an electronic device that converts one DC voltage into another required DC voltage; specifically, the DC-DC converter 112 may be a DC-DC converter (Direct current to direct current converter).

[0026] Series mode refers to a connection method in which multiple power modules are connected end to end in logical order, with the output of the previous power unit serving as the input of the next power unit to supply power to the load.

[0027] Parallel mode refers to a connection method in which at least two output voltages are connected side by side, the inputs of multiple power supply units are connected in parallel, and the outputs of multiple power supply units are connected in parallel to form a common output terminal to supply power to the load.

[0028] External system 200 refers to a power network that is electrically connected to, exchanges power with, or interacts with battery system 100 through connection to the second terminal of switching circuit 120. External system 200 can have any number of phases and any wiring method; for example, external system 200 may include a single-phase system, a two-phase system, and / or a three-phase system.

[0029] In one embodiment, when the controller 130 detects a voltage signal at the second terminal of the switching circuit 120, the battery system 100 is connected to the external power grid. The controller 130 controls the switching circuit 120 to switch to either parallel or series mode based on the voltage signal.

[0030] In another embodiment, when the controller 130 detects the absence of a voltage signal at the second terminal of the switching circuit 120, i.e., the battery system 100 is disconnected from the external power grid, i.e., the battery system 100 undergoes an off-grid black start. The controller 130 first controls the switching circuit 120 to switch to a first mode to start the external system 200. If the external system 200 fails to start, the controller controls the switching circuit 120 to switch to a second mode. The first mode is one of a parallel mode and a series mode, and the second mode is the other of a parallel mode and a series mode.

[0031] In this embodiment, the battery system 100 includes a battery circuit 110, a switching circuit 120, and a controller 130. The system includes a battery circuit 110 comprising at least two battery packs 111; a switching circuit 120 having a first end connected to the battery circuit 110 and a second end connected to an external system 200, and having a parallel mode and a series mode, wherein the parallel mode is configured to connect at least two battery packs 111 in parallel, and the series mode is configured to connect at least two battery packs 111 in series; and a controller 130 connected to the switching circuit 120, configured to: when a voltage signal is detected at the second end of the switching circuit 120, control the switching circuit 120 to switch to either the parallel mode or the series mode according to the voltage signal; or, when no voltage signal is detected at the second end of the switching circuit 120, first control the switching circuit 120 to switch to the first mode to start the external system 200, and if the external system 200 fails to start, control the switching circuit 120 to switch to the second mode. This enables the battery system 100 to start the external system 200 through series-parallel switching in both grid-connected and off-grid scenarios, saving the cost of code development, testing, and maintenance, and reducing the complexity of software management.

[0032] In some embodiments, controlling the switching circuit 120 to switch to parallel mode or series mode according to the voltage signal includes: when the amplitude of the voltage signal is within a first voltage range, the controller 130 controls the switching circuit 120 to switch to parallel mode; when the amplitude of the voltage signal is within a second voltage range, the controller 130 controls the switching circuit 120 to switch to series mode, wherein the minimum value of the second voltage range is greater than the maximum value of the first voltage range.

[0033] In one implementation, when the amplitude of the voltage signal is within a first voltage range, for example, the first voltage range may be 350V-450V, the controller 130 controls the switching circuit 120 to switch to parallel mode.

[0034] In another implementation, when the amplitude of the voltage signal is within the second voltage range, for example, the second voltage range may be 700V-900V, the controller 130 controls the switching circuit 120 to switch to the series mode.

[0035] The minimum value of the second voltage range is greater than the maximum value of the first voltage range.

[0036] In some examples, if the amplitude of the voltage signal is within the first voltage range, the external system 200 is determined to be a single-phase system. If the amplitude of the voltage signal is within the second voltage range, the external system 200 is determined to be a three-phase system.

[0037] In this embodiment, when the amplitude of the voltage signal is within the first voltage range, the controller 130 controls the switching circuit 120 to switch to parallel mode; when the amplitude of the voltage signal is within the second voltage range, the controller 130 controls the switching circuit 120 to switch to series mode. It can select series mode or parallel mode according to the amplitude of the voltage signal to adapt to different power consumption scenarios.

[0038] In some embodiments, when no voltage signal is detected at the second terminal of the switching circuit 120, the switching circuit 120 is first controlled to switch to the first mode to start the external system 200, and when the external system 200 fails to start, the switching circuit 120 is controlled to switch to the second mode, including: when no voltage signal is detected at the second terminal of the switching circuit 120, the switching circuit 120 is first controlled to switch to the parallel mode to start the external system 200, and when the external system 200 fails to start, the switching circuit 120 is controlled to switch to the series mode.

[0039] When no voltage signal is detected at the second terminal of the switching circuit 120, the battery system 100 is disconnected from the external power grid. The controller 130 first controls the switching circuit 120 to switch to parallel mode, causing at least two battery packs 111 to output in parallel to start the external system 200. If the external system 200 fails to start, the controller 130 controls the switching circuit 120 to switch to series mode, causing at least two battery packs 111 to output in series. If the external system 200 can be started in parallel mode, the switching circuit 120 remains in parallel mode, causing at least two battery packs 111 to output in parallel.

[0040] In this embodiment, when no voltage signal is detected at the second terminal of the switching circuit 120, the switching circuit 120 is first controlled to switch to parallel mode to start the external system 200. When the external system 200 fails to start, the switching circuit 120 is controlled to switch to series mode. This can improve the safety of system startup, ensure reliable startup and stable operation of the load, and enhance the fault tolerance of the system.

[0041] In some embodiments, after the switching circuit 120 switches to parallel mode or series mode, the controller 130 is further configured to: detect the output voltage of at least two battery packs 111 and the output voltage of the second terminal of the switching circuit 120 respectively, so as to determine whether the output voltage of at least two battery packs 111 through the switching circuit 120 matches the external system 200.

[0042] In one embodiment, the controller 130 detects the output voltage of at least two battery packs 111, for example, the output voltage can be 200V, 300V, 400V, 800V, etc. The controller 130 also detects the output voltage at the second terminal of the switching circuit 120. Based on the detected output voltage, the controller 130 determines whether the output voltage of the at least two battery packs 111 after passing through the switching circuit 120 matches that of the external system 200.

[0043] In some examples, the battery system 100 includes a voltage sampling circuit connected to the second terminals of both the controller 130 and the switching circuit 120, for acquiring the output voltage of the switching circuit 120. The voltage sampling circuit is an electronic circuit used to convert the voltage signal to be detected into an analog or digital signal that can be read by the controller 130. For example, the voltage sampling circuit detects the output voltage at the second terminal of the switching circuit 120 and sends the sampled voltage value to the controller 130. Based on the sampled voltage value, the controller 130 determines whether the output voltage of at least two battery packs 111 through the switching circuit 120 matches that of the external system 200.

[0044] In this embodiment, the controller 130 is further configured to detect the output voltage of at least two battery packs 111 and the output voltage of the second terminal of the switching circuit 120, respectively, to determine whether the output voltage of the at least two battery packs 111 through the switching circuit 120 matches the external system 200. This enables the system to avoid damage to the external system 200 or the battery packs 111 due to voltage mismatch, thereby improving the system's safety and reliability. The controller 130 can automatically determine whether the output voltage of the switching circuit 120 matches the external system 200 without manual adjustment or setting, thus achieving adaptive matching of the system.

[0045] In some embodiments, determining whether the output voltage of at least two battery packs 111 through the switching circuit 120 matches the external system 200 includes: in parallel mode, if the output voltage of the second terminal of the switching circuit 120 is the same as the output voltage of each battery pack 111, then determining that the output voltage of at least two battery packs 111 through the switching circuit 120 matches the external system 200; or, in series mode, if the output voltage of the second terminal of the switching circuit 120 is the sum of the output voltages of each battery pack 111, then determining that the output voltage of at least two battery packs 111 through the switching circuit 120 matches the external system 200.

[0046] In one embodiment, the controller 130 detects the output voltage of at least two battery packs 111 and the output voltage of the second terminal of the switching circuit 120. In parallel mode, if the output voltage of the second terminal of the switching circuit 120 is the same as the output voltage of each battery pack 111, it is determined that the output voltage of at least two battery packs 111 through the switching circuit 120 is matched with the external system 200. For example, if the output voltage of at least two battery packs 111 is 400V and the output voltage of the second terminal of the switching circuit 120 is 400V, then the output voltage of the second terminal of the switching circuit 120 is the same as the output voltage of at least two battery packs 111, and it is determined that the output voltage of at least two battery packs 111 through the switching circuit 120 is matched with the external system 200.

[0047] In another embodiment, the controller 130 detects the output voltage of at least two battery packs 111 and the output voltage of the second terminal of the switching circuit 120. In series mode, if the output voltage of the second terminal of the switching circuit 120 is the sum of the output voltages of each battery pack 111, it is determined that the output voltage of at least two battery packs 111 through the switching circuit 120 matches the external system 200. For example, if the output voltage of at least two battery packs 111 is 400V and the output voltage of the second terminal of the switching circuit 120 is 800V, then the output voltage of the second terminal of the switching circuit 120 is the sum of the output voltages of each battery pack 111, and it is determined that the output voltage of at least two battery packs 111 through the switching circuit 120 matches the external system 200.

[0048] In this embodiment, in parallel mode, if the output voltage of the second terminal of the switching circuit 120 is the same as the output voltage of each battery pack 111, it is determined that the output voltage of at least two battery packs 111 through the switching circuit 120 matches the external system 200; or, in series mode, if the output voltage of the second terminal of the switching circuit 120 is the sum of the output voltages of each battery pack 111, it is determined that the output voltage of at least two battery packs 111 through the switching circuit 120 matches the external system 200. This avoids the generation of large current circulating current, prevents damage to the battery packs 111, and protects the battery packs 111 and the switching circuit 120. By detecting whether the output voltage of the switching circuit 120 meets the voltage matching conditions of the corresponding mode, the controller 130 can safely switch between parallel and series modes, ensuring that the battery system 100 and the external system 200 can operate stably.

[0049] In some embodiments, when it is determined that the output voltage of at least two battery packs 111 via the switching circuit 120 does not match the external system 200, the controller 130 is further configured to: send an alarm signal; and / or disable the output of the battery circuit 110.

[0050] An alarm signal is a warning or fault indication signal generated by the controller 130 when the output voltage of the second terminal of the switching circuit 120 does not match the external system 200.

[0051] In one implementation, in parallel mode, when the controller 130 determines that the output voltage of at least two battery packs 111 through the switching circuit 120 does not match the external system 200, for example, if the output voltage of at least two battery packs 111 is 400V and the output voltage of the second terminal of the switching circuit 120 is not 400V, the controller 130 sends an alarm signal to warn the switching circuit 120 that the switching is not in place.

[0052] In this embodiment, when the controller 130 determines that the output voltage of the switching circuit 120 of at least two battery packs 111 does not match the external system 200, it is also used to: send an alarm signal; and / or disable the output of the battery circuit 110, which can avoid voltage mismatch or short circuit caused by incorrect connection and improve the safety and reliability of the system.

[0053] In some embodiments, such as Figure 2As shown, the switching circuit 120 includes a first switching element RLY1 and a second switching element RLY2. The first switching element RLY1 has a first set of ends for connecting to the positive terminals of at least two battery packs 111 and a second set of ends for connecting to the negative terminals of the second terminal of the switching circuit 120. The second switching element RLY2 has a first set of ends for connecting to the negative terminals of at least two battery packs 111 and a second set of ends for connecting to the positive terminals of the second terminal of the switching circuit 120. The first switching element RLY1 and the second switching element RLY2 cooperate to switch between parallel mode and series mode.

[0054] The first switching element RLY1 and the second switching element RLY2 refer to a switching device having two sets of independent contacts, each set of contacts including a common terminal and two selectable paths.

[0055] In some examples, in parallel mode, the first switching element RLY1 and the second switching element RLY2 are switched to the parallel position, the positive terminals of at least two battery packs 111 are connected to the positive terminal of the second terminal of the switching circuit 120, and the negative terminals of at least two battery packs 111 are connected to the negative terminal of the second terminal of the switching circuit 120.

[0056] In some examples, in series mode, the first switching element RLY1 and the second switching element RLY2 are switched to the series position, the positive terminal of one of the at least two battery packs 111 is connected to the positive terminal of the second terminal of the switching circuit 120, the negative terminal of one of the at least two battery packs 111 is connected to the positive terminal of the other battery pack 111, and the negative terminal of the other battery pack 111 is connected to the negative terminal of the second terminal of the switching circuit 120.

[0057] As described above, the battery pack 111 may include a DC-DC converter 112 and a battery. In some examples, the DC-DC converter 112 may include a first DC-DC converter DC1 and a second DC-DC converter DC2. The first switching element RLY1 and the second switching element RLY2 may be double-pole double-throw relays, for example, the first switching element RLY1 and the second switching element RLY2 may be HF115F012-2ZS4 relays. Specifically, pins 1 and 8 of the first switching element RLY1 are connected to the coil; pin 2 of the first switching element RLY1 is connected to pin 2 of the second switching element RLY2; pin 3 of the first switching element RLY1 is connected to the positive terminal of the first DC-DC converter DC1 and the negative terminal of the second terminal of the switching circuit 120, respectively; pin 4 of the first switching element RLY1 is connected to pin 4 of the second switching element RLY2; pin 5 of the first switching element RLY1 is connected to pin 5 of the second switching element RLY2; pin 6 of the first switching element RLY1 is connected to the positive terminal of the second DC-DC converter DC2; and pin 7 of the first switching element RLY1 is connected to the positive terminal of the first DC-DC converter DC1. Pins 1 and 8 of the second switching element RLY2 are connected to the coil; pin 3 of the second switching element RLY2 is used to connect to the positive terminal of the second terminal of the switching circuit 120; pin 6 of the second switching element RLY2 is connected to the negative terminal of the first DC-DC converter DC1; and pin 7 of the second switching element RLY2 is connected to the negative terminal of the second DC-DC converter DC2.

[0058] In this embodiment, the switching circuit 120 includes a first switching element RLY1 and a second switching element RLY2. The first switching element RLY1 has a first set of ends for connecting to the positive terminals of at least two battery packs 111 and a second set of ends for connecting to the negative terminals of the second terminal of the switching circuit 120. The second switching element RLY2 has a first set of ends for connecting to the negative terminals of at least two battery packs 111 and a second set of ends for connecting to the positive terminals of the second terminal of the switching circuit 120. The first switching element RLY1 and the second switching element RLY2 cooperate to switch between parallel mode and series mode, enabling the switching circuit 120 to have both parallel and series modes to be compatible with the operating voltage of different types of external systems 200.

[0059] In some embodiments, the controller 130 is configured to, before the external system 200 fails to start, include at least one of the following: receiving a voltage alarm signal from the external system 200; or, not receiving a startup success signal from the external system 200 within a preset time period.

[0060] A voltage alarm signal is an alarm or fault indication signal issued when the output voltage of the second terminal of the switching circuit 120 exceeds the normal operating voltage range of the external system 200. For example, the output voltage of the second terminal of the switching circuit 120 may be higher than the normal operating voltage range of the external system 200, i.e., overvoltage. Conversely, the output voltage of the second terminal of the switching circuit 120 may be lower than the normal operating voltage range of the external system 200, i.e., undervoltage.

[0061] A successful startup signal is a status signal issued by the external system 200 indicating that it can work normally.

[0062] When the controller 130 detects that there is no voltage signal at the second terminal of the switching circuit 120, i.e., when the battery system 100 is disconnected from the external power grid, it first controls the switching circuit 120 to switch to parallel mode to start the external system 200. If the controller 130 receives a voltage alarm signal from the external system 200, it indicates that the output voltage at the second terminal of the switching circuit 120 does not meet the operating voltage range of the external system 200, and the controller 130 determines that the external system 200 has failed to start. If the controller 130 does not receive a start-up success signal from the external system 200 within a preset time, it indicates that the external system 200 has not started successfully, and the controller determines that the external system 200 has failed to start. For example, the preset time can be 3 seconds, 5 seconds, etc.

[0063] For example, when the external system 200 is a single-phase system, its operating voltage range can be 350V-450V. If the output voltage at the second terminal of the switching circuit 120 is less than 350V, it indicates that the external system 200 is undervoltage, and the external system 200 will issue a voltage alarm signal. If the output voltage at the second terminal of the switching circuit 120 is greater than 450V, it indicates that the external system 200 is overvoltage, and the external system 200 will issue a voltage alarm signal.

[0064] In this embodiment, the controller 130 is used to detect whether the external system 200 is abnormally starting before the external system 200 fails to start, including at least one of the following: receiving a voltage alarm signal from the external system 200; or, if no start-up success signal from the external system 200 is received within a preset time period, it can quickly determine the fault state and improve the safety and reliability of the battery system 100.

[0065] In some embodiments, the controller 130 is further configured to: when a voltage signal is detected at the second terminal of the switching circuit 120, the battery system 100 is in a grid-connected state; or, when a voltage signal is not detected at the second terminal of the switching circuit 120, the battery system 100 is in an off-grid state.

[0066] Grid-connected state refers to the operating state in which the battery system 100 is electrically connected to the external power grid, and bidirectional power transmission is possible between the battery system 100 and the external power grid. Off-grid state refers to the operating state in which the battery system 100 is electrically disconnected from the external system 200, the external power grid stops supplying power, and the battery system 100 operates independently, disconnected from the external power grid.

[0067] When the controller 130 detects a voltage signal at the second terminal of the switching circuit 120, it indicates that the external power grid will continuously output a stable voltage signal to the battery system 100, and the battery system 100 is in a grid-connected state.

[0068] When the controller 130 detects that there is no voltage signal at the second terminal of the switching circuit 120, it indicates that the battery system 100 is disconnected from the external power grid and is operating independently, and the battery system 100 is in an off-grid state.

[0069] In this embodiment, the controller 130 is also used to: when a voltage signal is detected at the second terminal of the switching circuit 120, the battery system 100 is in a grid-connected state; or, when no voltage signal is detected at the second terminal of the switching circuit 120, the battery system 100 is in an off-grid state. This enables real-time sensing of changes in grid connection and disconnection, improves the response speed of system mode switching, and enhances the overall operational stability and environmental adaptability of the battery system 100.

[0070] In some embodiments, such as Figure 2 As shown, the battery circuit 110 includes at least two battery packs 111, wherein the battery pack 111 includes a battery and a DC-DC converter 112.

[0071] The DC-DC converter 112 may include a first DC-DC converter DC1 and a second DC-DC converter DC2, and the battery may include a first battery 111A and a second battery 111B. The first battery 111A is connected to the first DC-DC converter DC1, and the second battery 111B is connected to the second DC-DC converter DC2. The positive terminals of the first DC-DC converter DC1 and the second DC-DC converter DC2 are respectively connected to the switching circuit 120, and the negative terminals of the first DC-DC converter DC1 and the second DC-DC converter DC2 are respectively connected to the switching circuit 120. One end of the second capacitor C2 is connected to the positive terminal of the first DC-DC converter DC1, and the other end of the second capacitor C2 is connected to the negative terminal of the first DC-DC converter DC1. One end of the third capacitor C3 is connected to the positive terminal of the second DC-DC converter DC2, and the other end of the third capacitor C3 is connected to the negative terminal of the second DC-DC converter DC2.

[0072] In some examples, the first capacitor C1, the second capacitor C2, and the third capacitor C3 can be filter capacitors used for filtering and voltage regulation to reduce voltage ripple of the output voltage of the switching circuit 120 and the voltage of at least two voltages provided by the battery circuit 110.

[0073] Please see Figure 3 , Figure 3 This is a flowchart illustrating a control method for a battery system according to an embodiment of this application. This method can be applied to the controller 130 of the battery system 100 as described in the above embodiments. The battery system 100 includes a battery circuit 110, a switching circuit 120, and a controller 130. The switching circuit 120 has a parallel mode and a series mode. In the parallel mode, at least two battery packs 111 of the battery circuit 110 are connected in parallel; in the series mode, at least two battery packs 111 are connected in series. The structure and connection method of the battery system 100 are detailed in the above embodiments and will not be repeated here. It should be noted that if substantially the same result is achieved, the method of this application does not necessarily require the same result. Figure 3 The sequence of processes shown is limited.

[0074] like Figure 3 As shown, the method may include the following steps: Step S31: Detect whether there is a voltage signal at the output terminal of the switching circuit used to connect to the external system. Step S32: If a voltage signal exists, control the switching circuit to switch to either parallel mode or series mode based on the voltage signal. Step S33: If no voltage signal exists, first control the switching circuit to switch to the first mode to start the external system. If the external system fails to start, control the switching circuit to switch to the second mode. The first mode is one of parallel mode and series mode, and the second mode is the other.

[0075] In one embodiment, when the controller 130 detects a voltage signal at the second terminal of the switching circuit 120, the battery system 100 is connected to the external power grid. The controller 130 controls the switching circuit 120 to switch to either parallel or series mode based on the voltage signal.

[0076] In another embodiment, when the controller 130 detects the absence of a voltage signal at the second terminal of the switching circuit 120, i.e., the battery system 100 is disconnected from the external power grid, i.e., the battery system 100 undergoes an off-grid black start. The controller 130 first controls the switching circuit 120 to switch to a first mode to start the external system 200. If the external system 200 fails to start, the controller controls the switching circuit 120 to switch to a second mode. The first mode is one of a parallel mode and a series mode, and the second mode is the other of a parallel mode and a series mode.

[0077] In this embodiment, the presence of a voltage signal is detected at the output terminal of the switching circuit 120 used to connect to the external system 200. If a voltage signal is present, the switching circuit 120 is controlled to switch to either parallel or series mode based on the voltage signal. If no voltage signal is present, the switching circuit 120 is first controlled to switch to the first mode to start the external system 200. If the external system 200 fails to start, the switching circuit 120 is controlled to switch to the second mode. The first mode is one of the parallel and series modes, and the second mode is the other. This enables the battery system 100 to start the external system 200 by switching between series and parallel modes in both grid-connected and off-grid scenarios, saving the cost of code development, testing, and maintenance, and reducing the complexity of software management.

[0078] Please see Figure 4 , Figure 4 This is a schematic diagram of the structure of an energy storage battery according to an embodiment of this application. Figure 4 As shown, the energy storage battery 400 includes an inverter 420 and a battery system 410. The inverter 420 serves as the second terminal of the switching circuit in the battery system 410, connected to an external system. For example, the battery system 410 can be the battery system 100 as described in the above embodiment; the description of the battery system 100 is detailed in the above embodiment description and will not be repeated here. The inverter 420, as an external system, can be the external system 200 as described in the above embodiment; the description of the external system is detailed in the above embodiment description and will not be repeated here. It should be noted that the following description will use the battery system 410 as the battery system 100 of the above embodiment.

[0079] The energy storage battery 400 refers to an energy storage device that integrates the battery system 410 and the inverter 420, used to achieve bidirectional conversion between AC and DC power to complete the storage and release of electrical energy. The inverter 420 refers to an electronic device that performs bidirectional conversion between DC and AC power, such as a single-phase inverter or a three-phase inverter.

[0080] Single-phase electricity is a form of electrical energy consisting of a single AC potential source whose amplitude varies periodically with time in a sinusoidal pattern. It is used to provide power to commercial and residential users, and its rated voltage is 220V. Three-phase electricity is a form of electrical energy consisting of three AC potential sources with equal amplitude, the same frequency, a phase difference of 120°, and each varying periodically in a sinusoidal pattern. It is used to provide power to industrial equipment and high-power loads, and its rated voltage is 380V.

[0081] In this embodiment, the energy storage battery 400 includes an inverter 420 and a battery system 410. The inverter 420 serves as the second terminal of the switching circuit between the external system and the battery system 410, enabling the battery system 410 to start the external system in both grid-connected and off-grid scenarios through series-parallel switching. This saves on code development, testing, and maintenance costs and reduces the complexity of software management.

[0082] In an application scenario, such as Figures 1-2 The diagram illustrates a scenario where the battery system 100 is connected to the grid. Specifically, the battery system 100 is connected to the external power grid. When the controller 130 detects a voltage signal at the second terminal of the switching circuit 120, it initiates rectification to convert the AC power obtained from the external power grid into DC power. Next, the controller 130 acquires the amplitude of the voltage signal and performs voltage determination based on the amplitude. When the voltage signal amplitude falls within a first voltage range, for example, 350V-450V, the controller 130 controls the switching circuit 120 to switch to parallel mode, determining that the single-phase system is connected to the switching circuit 120. When the voltage signal amplitude falls within a second voltage range, for example, 700V-900V, the controller 130 controls the switching circuit 120 to switch to series mode, determining that the three-phase system is connected to the switching circuit 120.

[0083] In series mode, controller 130 controls the first switching element RLY1 and the second switching element RLY2 in switching circuit 120 to switch to series mode. That is, the positive terminal of one of the at least two battery packs 111 is connected to the positive terminal of the second terminal of switching circuit 120, the negative terminal of one of the at least two battery packs 111 is connected to the positive terminal of the other battery pack 111, and the negative terminal of the other battery pack 111 is connected to the negative terminal of the second terminal of switching circuit 120.

[0084] In parallel mode, the controller 130 controls the first switching element RLY1 and the second switching element RLY2 in the switching circuit 120 to switch to parallel mode. That is, the positive terminals of at least two battery packs 111 are connected to the positive terminal of the second terminal of the switching circuit 120, and the negative terminals of at least two battery packs 111 are connected to the negative terminal of the second terminal of the switching circuit 120.

[0085] The controller 130 detects the output voltage of at least two battery packs 111 and the output voltage of the second terminal of the switching circuit 120 respectively, and determines whether the output voltage of at least two battery packs 111 through the switching circuit 120 matches the external system 200.

[0086] In series mode, if the output voltage of the second terminal of the switching circuit 120 is the sum of the output voltages of each battery pack 111, then it is determined that the output voltages of at least two battery packs 111 through the switching circuit 120 are matched with the external system 200.

[0087] In parallel mode, if the output voltage of the second terminal of the switching circuit 120 is the same as the output voltage of each battery pack 111, it is determined that the output voltage of at least two battery packs 111 through the switching circuit 120 is matched with the external system 200.

[0088] When the controller 130 determines that the output voltage of at least two battery packs 111 through the switching circuit 120 matches the external system 200, the controller 130 sends an enable signal, such as a DC-DC enable signal, and the battery circuit 110 operates.

[0089] When the controller 130 determines that the output voltage of at least two battery packs 111 through the switching circuit 120 is not matched with the external system 200, the controller 130 sends an alarm signal and / or disables the output of the battery circuit 110.

[0090] In an application scenario, such as Figures 1-2 As shown, this is a scenario where the battery system 100 is started off-grid. Specifically, the battery system 100 is disconnected from the external power grid. When the controller 130 detects that there is no voltage signal at the second terminal of the switching circuit 120, it first controls the switching circuit 120 to switch to parallel mode to start the external system 200.

[0091] In parallel mode, the controller 130 controls the first switching element RLY1 and the second switching element RLY2 in the switching circuit 120 to switch to parallel mode. That is, the positive terminals of at least two battery packs 111 are connected to the positive terminal of the second terminal of the switching circuit 120, and the negative terminals of at least two battery packs 111 are connected to the negative terminal of the second terminal of the switching circuit 120. The second terminal of the switching circuit 120 outputs a voltage of 400V.

[0092] If the controller 130 receives a start-up success signal from the external system 200, it means that the output voltage of the second terminal of the switching circuit 120 can start the external system 200, and the output voltage of at least two battery packs 111 can start the external system 200 to work.

[0093] The controller 130 detects the output voltage of at least two battery packs 111 and the output voltage of the second terminal of the switching circuit 120 respectively, and determines whether the output voltage of at least two battery packs 111 through the switching circuit 120 matches the external system 200.

[0094] In parallel mode, if the output voltage of the second terminal of the switching circuit 120 is the same as the output voltage of each battery pack 111, it is determined that the output voltage of at least two battery packs 111 through the switching circuit 120 is matched with the external system 200.

[0095] When the controller 130 determines that the output voltage of at least two battery packs 111 through the switching circuit 120 matches the external system 200, the controller 130 sends an enable signal, such as a DC-DC enable signal, and the battery circuit 110 operates.

[0096] If the controller 130 receives a voltage alarm signal from the external system 200, it indicates that the output voltage at the second terminal of the switching circuit 120 is insufficient to start the external system 200, and the output voltage of at least two battery packs 111 is insufficient to start the external system 200. The controller 130 switches the switching circuit 120 to series mode.

[0097] In series mode, controller 130 controls the first switching element RLY1 and the second switching element RLY2 in switching circuit 120 to switch to series mode. That is, the positive terminal of one of the at least two battery packs 111 is connected to the positive terminal of the second terminal of switching circuit 120, the negative terminal of one of the at least two battery packs 111 is connected to the positive terminal of the other battery pack 111, and the negative terminal of the other battery pack 111 is connected to the negative terminal of the second terminal of switching circuit 120. The second terminal of switching circuit 120 outputs a voltage of 800V.

[0098] If the controller 130 receives a start-up success signal from the external system 200, it means that the output voltage of the second terminal of the switching circuit 120 can start the external system 200, and the output voltage of at least two battery packs 111 can start the external system 200 to work.

[0099] The controller 130 detects the output voltage of at least two battery packs 111 and the output voltage of the second terminal of the switching circuit 120 respectively, and determines whether the output voltage of at least two battery packs 111 through the switching circuit 120 matches the external system 200.

[0100] In series mode, if the output voltage of the second terminal of the switching circuit 120 is the sum of the output voltages of each battery pack 111, then it is determined that the output voltages of at least two battery packs 111 through the switching circuit 120 are matched with the external system 200.

[0101] Specifically, when the controller 130 determines that the output voltage of at least two battery packs 111 via the switching circuit 120 matches the external system 200, the controller 130 sends an enable signal, such as a DC-DC enable signal, and the battery circuit 110 operates. Those skilled in the art will understand that in the above method of the specific implementation, the order in which the steps are written does not imply a strict execution order and does not constitute any limitation on the implementation process; the specific execution order of each step should be determined by its function and possible internal logic.

[0102] In some embodiments, the functions or modules of the apparatus provided in this disclosure can be used to perform the methods described in the above method embodiments. The specific implementation can be referred to the description of the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0103] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.

[0104] In the several embodiments provided in this application, it should be understood that the disclosed methods and apparatus can be implemented in other ways. For example, the apparatus implementations described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0105] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0106] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods of various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0107] Those skilled in the art will readily recognize that numerous modifications and variations can be made to the apparatus and method while maintaining the teachings of this application. Therefore, the above disclosure should be considered limited only by the scope of the appended claims.

Claims

1. A battery system, characterized in that, include: Battery circuitry, comprising at least two battery packs; The switching circuit has a first end connected to the battery circuit and a second end for connecting to an external system. It has a parallel mode and a series mode, wherein the parallel mode is configured to connect the at least two battery packs in parallel and the series mode is configured to connect the at least two battery packs in series. A controller, connected to the switching circuit, is configured to: when a voltage signal is detected at the second terminal of the switching circuit, control the switching circuit to switch to the parallel mode or the series mode according to the voltage signal; or, when no voltage signal is detected at the second terminal of the switching circuit, first control the switching circuit to switch to the first mode to start the external system, and when the external system fails to start, control the switching circuit to switch to the second mode. The first mode is one of the parallel mode and the series mode, and the second mode is the other.

2. The battery system according to claim 1, characterized in that, The step of controlling the switching circuit to switch to the parallel mode or the series mode according to the voltage signal includes: When the amplitude of the voltage signal is within the first voltage range, the controller controls the switching circuit to switch to the parallel mode; When the amplitude of the voltage signal is within the second voltage range, the controller controls the switching circuit to switch to the series mode. The minimum value of the second voltage range is greater than the maximum value of the first voltage range.

3. The battery system according to claim 1, characterized in that, When a voltage signal is detected not at the second terminal of the switching circuit, the switching circuit is first controlled to switch to the first mode to start the external system; when the external system fails to start, the switching circuit is controlled to switch to the second mode, including: When no voltage signal is detected at the second terminal of the switching circuit, the switching circuit is first controlled to switch to the parallel mode to start the external system. If the external system fails to start, the switching circuit is controlled to switch to the series mode.

4. The battery system according to claim 1, characterized in that, After the switching circuit switches to the parallel mode or the series mode, the controller is further configured to: The output voltages of the at least two battery packs and the output voltage of the second terminal of the switching circuit are detected respectively to determine whether the output voltages of the at least two battery packs through the switching circuit match the external system.

5. The battery system according to claim 4, characterized in that, Determining whether the output voltage of the at least two battery packs through the switching circuit matches the external system includes: In the parallel mode, if the output voltage at the second terminal of the switching circuit is the same as the output voltage of each battery pack, then it is determined that the output voltage of at least two battery packs through the switching circuit matches the external system; or, In the series mode, if the output voltage of the second terminal of the switching circuit is the sum of the output voltages of each battery pack, then it is determined that the output voltage of the at least two battery packs through the switching circuit matches the external system.

6. The battery system according to claim 4, characterized in that, When it is determined that the output voltage of the at least two battery packs through the switching circuit does not match the external system, the controller is further configured to: Send an alarm signal; and / or disable the output of the battery circuit.

7. The battery system according to claim 1, characterized in that, The switching circuit includes a first switching element and a second switching element. The first switching element has a first set of ends for connection to the positive terminals of the at least two battery packs and a second set of ends for connection to the negative terminal of the second terminal of the switching circuit. The second switching element has a first set of ends for connection to the negative terminals of the at least two battery packs and a second set of ends for connection to the positive terminal of the second terminal of the switching circuit. The first switching element and the second switching element cooperate to switch between the parallel mode and the series mode.

8. The battery system according to claim 1, characterized in that, The controller is configured to include at least one of the following before the external system fails to boot: Receives a voltage alarm signal from the external system; or, No startup success signal was received from the external system within the preset time period.

9. The battery system according to claim 1, characterized in that, The controller is further configured to: when a voltage signal is detected at the second terminal of the switching circuit, the battery system is in a grid-connected state; or, when a voltage signal is not detected at the second terminal of the switching circuit, the battery system is in an off-grid state.

10. A control method for a battery system, characterized in that, A controller applied to the battery system, the battery system including a battery circuit, a switching circuit, and a controller, the switching circuit having a parallel mode and a series mode, wherein in the parallel mode at least two battery packs of the battery circuit are connected in parallel, and in the series mode the at least two battery packs are connected in series, the method comprising: The circuit detects whether a voltage signal exists at the output terminal of the switching circuit connected to the external system. If the voltage signal is present, the switching circuit is controlled to switch to the parallel mode or the series mode according to the voltage signal; If the voltage signal is not present, the switching circuit is first controlled to switch to the first mode to start the external system. If the external system fails to start, the switching circuit is controlled to switch to the second mode. The first mode is one of the parallel mode and the series mode, and the second mode is the other.

11. An energy storage battery, characterized in that, The energy storage battery includes an inverter and a battery system as described in any one of claims 1-9, wherein the inverter is connected as a second terminal of a switching circuit between the external system and the battery system.

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