Energy storage systems and battery modules

Abstract

This application provides an energy storage system and a battery module. The energy storage system includes: at least one battery module, which includes a battery cell, a first connection terminal, a second connection terminal, a first controllable switch, a second controllable switch, and a switch control unit. The positive terminal of the battery cell is connected to the first connection terminal via the first controllable switch, and the negative terminal is connected to the second connection terminal via the second controllable switch. The switch control unit controls the first and second controllable switches. An energy storage converter is also included, with its first terminal connected to AC power, its second terminal's positive terminal connected to the first connection terminal, and its negative terminal connected to the second connection terminal. A DC-DC converter is further included, with its first terminal connected to the second terminal of the energy storage converter, and its second terminal connected to the power supply terminal of the switch control unit. This application improves upon the problems of complex operation, high risk of human error, and high cost associated with the electrical isolation methods of related energy storage systems.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to energy storage systems and battery modules. Background Technology

[0002] According to the requirements of relevant energy storage system safety standards, in energy storage systems, electrical isolation devices should be installed between the external power supply terminals of battery modules and their internal energy storage units to achieve full-level isolation between the power supply terminals and the internal energy storage. This ensures that the power supply terminals are in a non-energized state when installing, maintaining, connecting, or disconnecting energy storage system equipment, reducing the safety risk caused by personnel accidentally touching energized parts.

[0003] To address these requirements, energy storage systems typically achieve electrical isolation by installing protective shells and insulation structures at the battery module terminals, or by adding multi-level electrical protection circuits. However, these isolation methods often rely on manual operation or complex electrical structures, resulting in cumbersome procedures and high requirements for the operational standards of installation and maintenance personnel. Furthermore, these solutions generally require the addition of numerous structural or electrical components, leading to complex system structures, high manufacturing and maintenance costs, and making it difficult to balance safety, reliability, and economy. Summary of the Invention

[0004] The purpose of this application is to provide energy storage systems and battery modules to improve the problems of complex operation, high risk of human error, high manufacturing and maintenance costs of related energy storage systems due to their electrical isolation methods.

[0005] The objective of this application is achieved through the following technical solution: In a first aspect, this application provides an energy storage system, comprising: at least one battery module, the battery module including a battery cell, a first connection terminal, a second connection terminal, a first controllable switch, a second controllable switch, and a switch control unit, wherein the positive terminal of the battery cell is connected to the first connection terminal via the first controllable switch, and the negative terminal of the battery cell is connected to the second connection terminal via the second controllable switch, and the switch control unit controls the first controllable switch and the second controllable switch; an energy storage converter, wherein a first terminal of the energy storage converter is used to connect to alternating current, the positive terminal of the second terminal of the energy storage converter is connected to the first connection terminal, and the negative terminal of the second terminal of the energy storage converter is connected to the second connection terminal; and a DC-DC converter, wherein a first terminal of the DC-DC converter is connected to the second terminal of the energy storage converter, and the second terminal of the DC-DC converter is connected to the power supply terminal of the switch control unit.

[0006] In some embodiments, the energy storage system further includes: a circuit breaker, a first terminal of which is connected to a first terminal of the DC-DC converter, a second terminal of which is connected to a second terminal of the energy storage converter, and the positive and negative terminals of the second terminal of the energy storage converter are connected to the first connection terminal and the second connection terminal through the circuit breaker.

[0007] In some embodiments, the switch control unit includes: at least one first switch, wherein the at least one first switch is connected in series with a driving element at the second terminal of the DC-DC converter, the driving element being configured to drive the first controllable switch and the second controllable switch to conduct in response to the conduction of at least one first switch; and a first switch driving circuit, wherein the first switch driving circuit is connected to the second terminal of the DC-DC converter, the first switch driving circuit being configured to drive the first switch.

[0008] In some embodiments, the battery module further includes: an analog front-end chip, the power supply terminal of which is connected to the battery cell; at least one second switch, which is connected in series with the driving element between the positive and negative terminals of the battery cell, the driving element being used to drive the first controllable switch and the second controllable switch to conduct in response to the second switch being turned on; and a second switch driving circuit, which is connected to the output terminal of the analog front-end chip to drive the second switch according to the driving control signal output by the analog front-end chip.

[0009] In some implementations, the analog front-end chip is used to provide the drive control signal to the second switch drive circuit in the event of a failure in the first switch drive circuit.

[0010] In some embodiments, the energy storage system further includes a battery monitoring unit, which generates a wake-up signal when it detects a fault in the first switch drive circuit; the analog front-end chip operates after receiving the wake-up signal and provides drive control signals to the second switch drive circuit.

[0011] In some embodiments, the first controllable switch and the second controllable switch are electromagnetic switches, and the driving element is a driving coil.

[0012] Secondly, this application provides a battery module for use in an energy storage system, the energy storage system further including an energy storage converter and a DC-DC converter; the battery module includes a battery cell, a first connection terminal, a second connection terminal, a first controllable switch, a second controllable switch, and a switch control unit; the positive terminal of the battery cell is connected to the first connection terminal through the first controllable switch, the negative terminal of the battery cell is connected to the second connection terminal through the second controllable switch, and the switch control unit controls the first controllable switch and the second controllable switch; wherein, the first terminal of the energy storage converter is used to connect to AC power, the positive terminal of the second terminal of the energy storage converter is connected to the first connection terminal, and the negative terminal of the second terminal of the energy storage converter is connected to the second connection terminal; the first terminal of the DC-DC converter is connected to the second terminal of the energy storage converter, and the second terminal of the DC-DC converter is connected to the power supply terminal of the switch control unit.

[0013] In some embodiments, the switch control unit includes: a first switch, a first terminal of which is connected to a second terminal of the DC-DC converter, and a second terminal of which is connected to a drive element for the first controllable switch and the second controllable switch, the drive element being configured to drive the first controllable switch and the second controllable switch to conduct in response to the first switch being turned on; and a first switch drive circuit, which is connected to the second terminal of the DC-DC converter and is configured to drive the first switch.

[0014] In some embodiments, the battery module further includes: an analog front-end chip, the power supply terminal of which is connected to the battery cell; a second switch, the positive and negative terminals of the first terminal of which are respectively connected to the positive and negative terminals of the battery cell, and the second terminal of which is connected to a driving element for the first controllable switch and the second controllable switch, the driving element being used to drive the first controllable switch and the second controllable switch to conduct in response to the second switch being turned on; and a second switch driving circuit, the second switch driving circuit being connected to the output terminal of the analog front-end chip to drive the second switch according to the driving control signal output by the analog front-end chip.

[0015] Thirdly, this application provides an energy storage system, including a switch box, an energy storage converter, and at least two stacked battery modules. The at least two battery modules include a first battery module to an Nth battery module connected in sequence. The switch box includes a DC-DC converter, where N is an integer greater than 1. Each battery module includes a battery cell, a first connection terminal, a second connection terminal, a first controllable switch, a second controllable switch, and a switch control unit. The positive terminal of the battery cell is connected to the first connection terminal through the first controllable switch, and the negative terminal of the battery cell is connected to the second connection terminal through the second controllable switch. The switch control unit controls the first controllable switch and the second controllable switch. The energy storage converter has a first terminal for connecting to AC power, a second terminal whose positive terminal is connected to the first connection terminal of the first battery module, and a second terminal whose negative terminal is connected to the second connection terminal of the Nth battery module. The DC-DC converter has a first terminal connected to the second terminal of the energy storage converter, and the second terminal connected to the power supply terminal of the switch control unit.

[0016] In some embodiments, the switch control unit includes: a first switch, a first terminal of which is connected to a second terminal of the DC-DC converter, and a second terminal of which is connected to a drive element for the first controllable switch and the second controllable switch, the drive element being configured to drive the first controllable switch and the second controllable switch to conduct in response to the first switch being turned on; and a first switch drive circuit, which is connected to the second terminal of the DC-DC converter and is configured to drive the first switch.

[0017] In some embodiments, the switch box includes the DC-DC converter, a circuit breaker, and a pre-charge relay; the first terminal of the circuit breaker is connected to the first terminal of the DC-DC converter, the second terminal of the circuit breaker is used to connect to the second terminal of the energy storage converter, the positive terminal of the second terminal of the energy storage converter is connected to the first connection terminal of the first battery module through the circuit breaker, and the negative terminal of the second terminal of the energy storage converter is connected to the second connection terminal of the Nth battery module through the circuit breaker; the pre-charge relay is connected in series between the first terminal of the circuit breaker and the first connection terminal of the first battery module, or the pre-charge relay is connected in series between the first terminal of the circuit breaker and the second connection terminal of the Nth battery module.

[0018] This application provides an energy storage system and a battery module. By setting a first controllable switch and a second controllable switch between the battery cell and the connection terminal, and powering the switch control unit through a DC-DC converter, the battery module can establish an electrical connection with the external circuit only when the energy storage converter has power supply conditions. This achieves controlled power-on of the battery terminals and reduces the risk of accidental energization of the battery terminals. By using the first and second controllable switches to form a battery port isolation structure, the battery terminals can be kept in a voltage-free state during the installation, maintenance, or disassembly of the energy storage system, thereby facilitating energy storage system maintenance and reducing the risk of electric shock and short circuit. Addressing the problems of complex operation, high risk of human error, and high cost of related energy storage system electrical isolation methods, this application adopts a port isolation control mechanism based on the linkage between controllable switches and power supply, thereby improving the reliability and economy of the energy storage system while ensuring its safety. Attached Figure Description

[0019] This application will be further described below with reference to the accompanying drawings and specific embodiments.

[0020] Figure 1 This is a structural block diagram of an energy storage system and a power converter provided in an embodiment of this application.

[0021] Figure 2 This is a structural block diagram of an energy storage system provided in an embodiment of this application.

[0022] Figure 3 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application.

[0023] Figure 4 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application.

[0024] Figure 5 This is a structural block diagram of a battery module provided in an embodiment of this application.

[0025] Figure 6 This is a startup flowchart of an energy storage system provided in an embodiment of this application. Detailed Implementation

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

[0027] In the description of the embodiments of this application, it should be understood that 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 indicated technical features. Therefore, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0028] According to relevant standards, isolation devices must be installed inside the battery module casing or at the power terminals to achieve full-level isolation between the power terminals and the internal energy storage, thereby ensuring that the connection or disconnection of the energy storage system equipment can be completed when the terminals are not energized.

[0029] Current energy storage systems (such as residential battery stacks) use physical and electrical design protection for electrical isolation, but this approach is complex to operate, carries a high risk of human error, and is costly.

[0030] See Figure 1 , Figure 1 This is a structural block diagram of an energy storage system and a power converter provided in an embodiment of this application.

[0031] To address the issues of complex operation, high risk of human error, and high cost associated with electrical isolation methods in related energy storage systems, this application provides an energy storage system comprising at least one battery module, an energy storage converter, and a DC-DC converter.

[0032] The battery module includes a battery cell, a first connection terminal, a second connection terminal, a first controllable switch KM1, a second controllable switch KM2, and a switch control unit. The positive terminal of the battery cell is connected to the first connection terminal through the first controllable switch KM1, and the negative terminal of the battery cell is connected to the second connection terminal through the second controllable switch KM2. The switch control unit controls the first controllable switch KM1 and the second controllable switch KM2.

[0033] The first terminal of the energy storage converter is used to connect to AC power. The positive terminal of the second terminal of the energy storage converter is connected to the first connection terminal, and the negative terminal of the second terminal of the energy storage converter is connected to the second connection terminal.

[0034] The first terminal of the DC-DC converter is connected to the second terminal of the energy storage converter, and the second terminal of the DC-DC converter is connected to the power supply terminal of the switch control unit.

[0035] An energy storage system is a complete power electronic device used to store and release electrical energy. It can be used to convert DC power from the battery side to AC power from the grid and to safely control the battery modules under different operating conditions. Energy storage systems can be applied to residential energy storage, industrial and commercial energy storage, microgrid systems, and off-grid power supply systems. By setting up controllable switches and power supply linkage mechanisms, the battery modules can be controlled to be connected or isolated from external circuits, thereby improving the operational safety of the energy storage system.

[0036] A battery module is a fundamental functional unit in an energy storage system used to store electrical energy. In addition to battery cells, the battery module in this embodiment includes connection terminals, a controllable switch, and a switch control unit. This structure enables the battery module to not only have energy storage capabilities but also port electrical isolation capabilities. The battery module can be of various types, such as lithium-ion battery modules, lithium iron phosphate battery modules, sodium-ion battery modules, and lead-acid battery modules. By adding a controllable switch between the battery cells and the connection terminals, the battery module can automatically adjust its external power connection status according to the operating status of the energy storage system.

[0037] A battery cell serves as the smallest energy storage unit in a battery module, used for the chemical storage and release of electrical energy. A battery cell may include a cell and its internal electrodes, electrolyte, and separator. Multiple battery cells can be connected in series or parallel to form a battery module to achieve the desired voltage level and capacity. In this embodiment, the energy output path of the battery cell is controllable through a first controllable switch KM1 and a second controllable switch KM2. The battery cell can take various forms, such as cylindrical cells, prismatic cells, or pouch cells; this embodiment does not limit this type.

[0038] The first and second connection terminals serve as the positive and negative output terminals of the battery module, respectively. The connection terminals can be interface components that establish an electrical connection between the battery module and the energy storage converter. The connection terminals can take the form of bolt-on terminals, plug-in terminals, or busbar structures. By connecting the positive and negative terminals of the battery cell to the connection terminals via controllable switches, the energization of the connection terminals depends entirely on the conduction state of the controllable switches, thereby achieving port safety isolation.

[0039] The first controllable switch KM1 is used to control the electrical connection between the positive terminal of the battery cell and the first connection terminal. When the first controllable switch KM1 is closed, the positive terminal of the battery cell is connected to the first connection terminal; when the first controllable switch KM1 is open, the positive terminal of the battery is isolated from the first connection terminal. The first controllable switch KM1 can be implemented using devices such as a DC contactor, a power relay, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), or a solid-state relay. By controlling the first controllable switch KM1, safe management of the current path of the battery positive terminal can be achieved.

[0040] The second controllable switch KM2 is used to control the electrical connection between the negative terminal of the battery cell and the second connection terminal. Its structure and operation are similar to the first controllable switch KM1. The second controllable switch KM2 can be implemented in various forms, such as a DC contactor, power relay, MOSFET, IGBT, or solid-state relay. By controlling the conduction states of the positive and negative terminals of the battery separately, a double-ended isolation structure can be constructed, thereby improving the electrical safety of the energy storage system and reducing the leakage risk that may occur with single-ended isolation.

[0041] The switch control unit is used to control the on / off state of the first controllable switch KM1 and the second controllable switch KM2. The switch control unit may include a control chip, drive circuit, power management module, and protection logic circuit. Responding to the power supply status of the energy storage system, the battery status, or the operating status of the energy storage converter, the switch control unit outputs a switch control to activate the controllable switches. The switch control unit can be implemented using a microcontroller, a battery management system controller, or a dedicated control circuit.

[0042] Energy storage converters can be used to convert energy between energy storage systems and the AC power grid. The first end of the energy storage converter connects to the AC power grid for power input or output; the second end connects to the battery module for DC-side energy exchange. Energy storage converters can take the form of bidirectional inverters, PCS (Power Conversion System), AC / DC converters, or DC / AC converters. In addition to energy conversion, energy storage converters can also serve as a power source for determining the power-on conditions of the battery terminals. AC / DC stands for Alternating Current / Direct Current, converting alternating current to direct current; DC / AC stands for Direct Current / Alternating Current, converting direct current to alternating current.

[0043] A DC-DC converter is used to convert the DC-side voltage of an energy storage converter into a suitable operating power supply for the switch control unit. DC-DC converters can take the form of isolated DC-DC converters, buck converters, boost converters, or bidirectional DC-DC converters. By placing the DC-DC converter between the energy storage converter and the switch control unit, the switch control unit's operating power depends on the energy storage converter, thus establishing a power supply linkage control mechanism.

[0044] In this embodiment, the conduction state of the controllable switch is determined by the switch control unit, and the operating power of the switch control unit is provided by the DC-DC converter. When the energy storage converter is operating normally and supplies power to the switch control unit through the DC-DC converter, the switch control unit drives the controllable switch to close, establishing an electrical connection between the battery module and the energy storage converter. When the energy storage converter stops supplying power or the energy storage system is in a disassembly and maintenance state, the DC-DC converter stops supplying power, and the switch control unit has difficulty driving the controllable switch, thereby automatically isolating the battery module from the external circuit.

[0045] This embodiment establishes a logical association between the energization status of the battery port and the power supply status of the energy storage converter by constructing a power supply authorization link. Specifically, the power supply status of the energy storage converter determines the output status of the DC-DC converter, which in turn determines the operating status of the switch control unit, which then controls the conduction status of the controllable switch. Through this multi-level linkage control mechanism, the battery module is only allowed to supply power externally when the energy storage system meets the operating conditions, thereby achieving port safety isolation and improving the operational reliability of the energy storage system.

[0046] In this embodiment, the positive terminal of the battery cell in the battery module is electrically connected to the first connection terminal via a first controllable switch KM1, and the negative terminal is electrically connected to the second connection terminal via a second controllable switch KM2. The switching on and off of the first and second controllable switches KM1 and KM2 are uniformly controlled by the switch control unit. The DC side of the energy storage converter is electrically connected to the first and second connection terminals of the battery module to realize energy conversion between the energy storage system and the AC side. A DC converter is disposed between the DC side of the energy storage converter and the switch control unit to provide operating power to the switch control unit. When the energy storage converter is in a power-supply state, the DC converter supplies power to the switch control unit. The switch control unit drives the first controllable switch KM1 and the second controllable switch KM2 to close, so that the battery unit is electrically connected to the energy storage converter, thereby enabling the battery module to supply power or charge. When the energy storage converter is not supplying power or the DC converter stops supplying power to the switch control unit, the switch control unit stops driving the first controllable switch KM1 and the second controllable switch KM2, so that the battery unit is disconnected from the first connection terminal and the second connection terminal, thereby achieving electrical isolation between the battery module and the external circuit.

[0047] This embodiment, by setting a first controllable switch KM1 and a second controllable switch KM2 between the battery cell and the connection terminal, and powering the switch control unit through a DC-DC converter, enables the battery module to establish an electrical connection with the external circuit only when the energy storage converter has power supply conditions. This achieves controlled power-on of the battery terminals and reduces the risk of accidental energization of the battery terminals. By linking the operating power supply of the switch control unit with the power supply status of the energy storage converter, the connection between the battery module and the external circuit can be automatically disconnected when the energy storage converter is abnormal or disconnected, thereby improving the operational safety and reliability of the energy storage system. By using the first controllable switch KM1 and the second controllable switch KM2 to form a battery port isolation structure, the battery terminals can be kept in a voltage-free state during the installation, maintenance, or disassembly of the energy storage system, thereby facilitating energy storage system maintenance and reducing the risk of electric shock and short circuit. By using a DC-DC converter to power the switch control unit, complex manual operation procedures and additional protective structures can be reduced, thereby reducing the manufacturing cost of the energy storage system and increasing the degree of structural simplification. This embodiment addresses the issues of complex operation, high risk of human error, and high cost associated with electrical isolation methods in related energy storage systems. It adopts a port isolation control mechanism based on the linkage between controllable switches and power supply, thereby improving the reliability and economy of the energy storage system while ensuring its safety.

[0048] See Figure 2 , Figure 2 This is a structural block diagram of an energy storage system provided in an embodiment of this application.

[0049] In some embodiments, the energy storage system may further include a circuit breaker CF, with a first terminal of the circuit breaker CF connected to a first terminal of a DC-DC converter, and a second terminal of the circuit breaker CF used to connect to a second terminal of the energy storage converter. The positive and negative terminals of the second terminal of the energy storage converter are connected to a first connection terminal and a second connection terminal through the circuit breaker CF.

[0050] A circuit breaker (CF) is an electrical switching device used to control the connection and disconnection of a circuit and provides fault protection. It establishes an electrical connection during normal operation and interrupts the current path in the event of overcurrent, short circuit, or abnormal operation. In this embodiment, the circuit breaker (CF) is positioned between the energy storage converter and the battery module, serving not only to achieve safe isolation of the main power circuit but also participating in the battery port power supply control logic. The circuit breaker (CF) can be implemented in various forms, including mechanical DC circuit breakers (CF), electronic solid-state circuit breakers (CF), intelligent protection circuit breakers (CF), or combined protection switches. By placing a circuit breaker (CF) in the system power path, the energy storage system can achieve rapid electrical isolation during faults or maintenance, thereby improving system operational safety.

[0051] The first terminal of the circuit breaker CF is used to connect to the first terminal of the DC-DC converter, serving as the connection node for the circuit breaker CF to access the control power supply link. This connection method allows the power supply status of the DC-DC converter input to be directly controlled by the opening and closing state of the circuit breaker CF. When the circuit breaker CF is closed, the DC-side voltage of the energy storage converter can be transmitted to the DC-DC converter through the circuit breaker CF; when the circuit breaker CF is open, the DC-DC converter input power supply is cut off, thereby affecting the power supply status of the switch control unit.

[0052] The second terminal of the circuit breaker CF is used to connect to the second terminal of the energy storage converter, participating in the formation of the power transmission channel between the DC side of the energy storage converter and the battery module. By placing the circuit breaker CF between the DC output terminal of the energy storage converter and the battery module, whether the output power of the energy storage converter can be transmitted to the battery module depends on the state of the circuit breaker CF. This structure makes the circuit breaker CF a control node in the power input and output path of the energy storage system, enabling energy isolation at the energy storage system level.

[0053] The second terminal of the energy storage converter is its DC-side output terminal, used for energy exchange with the battery module. In this embodiment, the second terminal of the energy storage converter includes a positive output terminal and a negative output terminal, which are respectively connected to the first and second connection terminals of the battery module via a circuit breaker CF. Through this port structure, the energy storage converter can realize battery charging, discharging, and energy dispatching functions of the energy storage system.

[0054] In this embodiment, the connection terminal establishes an electrical connection with the energy storage converter through the circuit breaker CF, so that whether the battery module port is energized is controlled not only by the internal controllable switch, but also by the state of the circuit breaker CF, thereby constructing a multi-level safety isolation structure.

[0055] In this embodiment, the state of the circuit breaker CF directly determines the electrical connection between the energy storage converter and the battery module. When the circuit breaker CF is closed, the DC-side voltage of the energy storage converter can be transmitted to the battery module through the circuit breaker CF, simultaneously providing input power to the DC-DC converter. This allows the switch control unit to drive the controllable switch to close, thereby establishing the electrical connection between the battery module and the energy storage converter. When the circuit breaker CF is open, the electrical connection between the energy storage converter and the battery module is severed, the DC-DC converter cannot receive power, the switch control unit stops driving the controllable switch, and the battery module is automatically isolated from the external circuit.

[0056] This embodiment establishes a multi-level isolation control mechanism for the energy storage system by placing a circuit breaker (CF) between the energy storage converter and the battery module, and linking the power supply path of the switch control unit with the state of the circuit breaker (CF). Specifically, the power supply state of the energy storage converter affects the input state of the DC-DC converter through the circuit breaker (CF), the output state of the DC-DC converter further determines the operating state of the switch control unit, and the switch control unit then controls the conduction state of the controllable switches inside the battery module. Through this hierarchical authorization control mechanism, the battery terminals are only allowed to be energized when the energy storage system meets the operating conditions, thereby effectively reducing the risk of accidental energization and improving the safety and stability of the energy storage system.

[0057] See Figure 3 , Figure 3 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application.

[0058] like Figure 3 As shown, an energy storage system may include battery modules, an energy storage converter (such as a PCS), and a DC-DC converter (such as a DC / DC converter). The energy storage system may also include a circuit breaker (CF). The DC-DC converter can be housed in a switch box, which may also contain a battery monitoring unit (such as a CMU) and a pre-charge relay (such as a KM). P+ and P- are the positive and negative terminals of the second end of the energy storage converter, respectively, and B+ and B- are the positive and negative terminals of the battery monitoring unit, respectively. CMU stands for Cell Monitoring Unit. CAN stands for Controller Area Network.

[0059] In some embodiments, the switch control unit may include at least one first switch S1 and a first switch drive circuit (such as an S1 drive). At least one first switch S1 is connected in series with a drive element at the second terminal of the DC-DC converter. The drive element is used to drive a first controllable switch KM1 and a second controllable switch KM2 to conduct in response to the conduction of at least one first switch S1. The first switch drive circuit is connected to the second terminal of the DC-DC converter and is used to drive the first switch S1.

[0060] The first switch S1 can be an execution controller in the switch control unit, used to control the electrical connection state between the drive element and the output terminal of the DC-DC converter. When the first switch S1 is on, the DC-DC converter output power supply is allowed to supply power to the drive element; when the first switch S1 is off, the drive element loses power supply, thereby preventing the first controllable switch KM1 and the second controllable switch KM2 from conducting. The first switch S1 can be a MOSFET, IGBT, power relay, solid-state relay, or bipolar transistor, among other switching devices. By setting the first switch S1, electronic control of the power supply path to the drive element can be achieved.

[0061] The first switch drive circuit, used to drive the first switch S1, is a control signal generation module in the switch control unit. Connected to the second terminal of the DC-DC converter, the first switch drive circuit generates a drive signal based on the output power state of the DC-DC converter, causing the first switch S1 to close or open. The first switch drive circuit may include a voltage detection module, a drive amplification module, a level conversion module, and protection circuits. Through the first switch drive circuit, the power supply state of the DC-DC converter can be converted into a drive signal for the first switch S1, thereby establishing a power supply linkage control mechanism.

[0062] The driving element is an intermediate execution module used to drive the first controllable switch KM1 and the second controllable switch KM2 to conduct after obtaining power supply conditions. The driving element can be used to provide appropriate driving voltage, current or control signal to enable the controllable switches to conduct stably. The driving element may include relay driving circuit, gate driving chip, power driving module or optocoupler isolation driving module, etc. By connecting the driving element in series with the first switch S1, the operating state of the driving element directly depends on the conduction state of the first switch S1, thereby realizing cascaded control of the controllable switches.

[0063] In this embodiment, the first switch S1 is connected in series with the driving element at the second terminal of the DC-DC converter, so that whether the driving element can obtain operating power depends on the conduction state of the first switch S1. When the first switch S1 is closed, the driving element can obtain the output power of the DC-DC converter and drive the controllable switch to conduct; when the first switch S1 is open, the driving element loses its power supply path, and the controllable switch remains in the open state. This series structure establishes a power authorization link, so that the driving signal can only act on the controllable switch after being authorized by the first switch S1.

[0064] In this embodiment, the conduction state of the first switch S1 is determined by the first switch driving circuit, which in turn depends on the power supply state of the DC-DC converter. When the DC-DC converter supplies power to the first switch driving circuit, the first switch driving circuit outputs a driving signal to close the first switch S1, thereby allowing the driving element to be powered and driving the first controllable switch KM1 and the second controllable switch KM2 to close, making the battery module port energized. When the DC-DC converter stops supplying power, the first switch driving circuit stops outputting the driving signal, causing the first switch S1 to open, thereby cutting off the power supply path to the driving element and automatically isolating the battery module from the external circuit.

[0065] This embodiment constructs a cascaded control structure in the switch control unit, comprising a first switch S1, a driving element, and controllable switches (including a first controllable switch KM1 and a second controllable switch KM2). This structure is then linked to the power supply status of the DC-DC converter to achieve multi-level authorized control of the battery port's energized state. Specifically, the DC-DC converter's power supply status determines the operating state of the first switch driving circuit, which in turn controls the conduction state of the first switch S1. The first switch S1 further determines whether the driving element can drive the controllable switches to conduct, thus ensuring that the battery module is only allowed to establish an electrical connection when the energy storage system meets its operating conditions. This cascaded control mechanism effectively reduces accidental energization of the battery port, improving the safety and operational reliability of the energy storage system.

[0066] See Figure 4 , Figure 4 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application.

[0067] like Figure 4 As shown, in some embodiments, in Figure 3 Based on this, the battery module may further include an analog front-end chip (such as an AFE), at least one second switch S2, and a second switch drive circuit (such as an S2 drive). The power supply terminal of the analog front-end chip is connected to the battery cell. At least one second switch S2 is connected in series with a drive element between the positive and negative terminals of the battery cell. The drive element is used to drive the first controllable switch KM1 and the second controllable switch KM2 to conduct in response to the conduction of the second switch S2. The second switch drive circuit is connected to the output terminal of the analog front-end chip to drive the second switch S2 according to the drive control signal output by the analog front-end chip.

[0068] An analog front-end (AFE) chip can be a functional chip located inside the battery module and electrically connected to the battery cells. It is used to collect operating parameters of the battery cells, such as voltage, current, and temperature, and can provide logic control outputs and power management functions. In this embodiment, the analog front-end chip is not only used for battery status detection but also undertakes the internal wake-up control function of the battery module. Its power supply terminal is connected to the battery cells, enabling them to be in standby or operating state when the battery module has basic electrical energy. The analog front-end chip can take the form of a dedicated battery management sampling chip, a multi-channel voltage acquisition chip, or an integrated battery monitoring chip. By using the control signals output by the analog front-end chip, the battery-side power supply drive link can be established.

[0069] The second switch S2 can be a control switch device located inside the battery module, used to control the electrical connection state between the drive element and the battery cell. At least one second switch S2 is connected in series with the drive element between the positive and negative terminals of the battery cell, so that whether the drive element receives power from the battery depends on the conduction state of the second switch S2. The second switch S2 can be implemented in various forms such as MOSFET, IGBT, relay, solid-state relay, or bipolar transistor. By setting the second switch S2, the power supply path of the drive element is controllable, thereby realizing the active control port conduction function on the battery side.

[0070] The second switch driver circuit is used to drive the second switch S2 to turn on or off, and it is connected to the output terminal of the analog front-end chip. The second switch driver circuit can generate a drive voltage or drive current based on the drive control signal output by the analog front-end chip, causing the second switch S2 to close or open. The second switch driver circuit may include a level conversion module, a signal amplification module, a power supply regulation module, and protection circuits, etc. Through the second switch driver circuit, the drive control signal output by the analog front-end chip can be converted into a drive signal that can directly drive the second switch S2, thereby establishing a battery-side power supply control path.

[0071] In this embodiment, the operating state of the driving element can be controlled by the first switch S1 or the second switch S2, so that the driving element can obtain battery power when the first switch S1 or the second switch S2 is closed, thereby realizing battery port conduction control.

[0072] In this embodiment, the second switch S2 is connected in series with the driving element between the positive and negative terminals of the battery cell, so that the power supply path of the driving element is controlled by the second switch S2. When the second switch S2 is closed, the driving element can obtain power from the battery cell, thereby driving the first controllable switch KM1 and the second controllable switch KM2 to close; when the second switch S2 is open, the power supply path of the driving element is cut off, and the controllable switches remain in the open state. This series structure establishes a control link based on battery-side power supply authorization, enabling battery port conduction to be achieved when the control authorization of the analog front-end chip is satisfied.

[0073] In this embodiment, the conduction state of the second switch S2 is determined by the second switch driving circuit, which is driven by the drive control signal output by the analog front-end chip. When the analog front-end chip is in operation and outputs the drive control signal, the second switch driving circuit drives the second switch S2 to close, enabling the driving element to receive battery power and driving the first controllable switch KM1 and the second controllable switch KM2 to close, thereby energizing the battery module port. When the analog front-end chip is in standby mode or does not output a drive signal, the second switch S2 is open, the driving element cannot receive power, and the battery module remains isolated. This control logic realizes the active wake-up function on the battery side.

[0074] This embodiment constructs a cascaded control structure within the battery module, comprising an analog front-end chip, a second switch drive circuit, a second switch S2, and drive elements, enabling the battery module to achieve port conduction control based on battery-side power supply. Specifically, the drive control signal output by the analog front-end chip determines the operating state of the second switch drive circuit, which in turn controls the conduction state of the second switch S2. The second switch S2 further determines the power supply state of the drive elements, which in turn control the conduction states of the first controllable switch KM1 and the second controllable switch KM2. Through this multi-level authorized control mechanism, the battery module can autonomously wake up when external power supply is unavailable, while ensuring that the battery ports are only allowed to be energized when safety conditions are met, thereby improving the operational flexibility and safety of the energy storage system.

[0075] In some embodiments, the analog front-end chip can be used to provide drive control signals to the second switch drive circuit in the event of a failure in the first switch drive circuit.

[0076] In this embodiment, the analog front-end chip can serve as a backup control function. When the first switch drive circuit in the energy storage system fails, the analog front-end chip can act as a backup control signal source, outputting drive control signals to the second switch drive circuit. By setting the analog front-end chip inside the battery module, a redundant control link based on battery-side power supply can be constructed.

[0077] The first switch drive circuit is used to drive the first switch S1 based on the power supply status of the DC-DC converter. A fault in the first switch drive circuit can occur, for example, by the first switch drive circuit being unable to output a valid drive signal. In this embodiment, a fault in the first switch drive circuit can include, but is not limited to, various situations such as no output from the DC-DC converter, a disconnected power path, damage to components in the first switch drive circuit, or the energy storage system being in an off-grid or black-start state. When the first switch drive circuit cannot provide a drive signal, the original port conduction control link based on the energy storage converter power supply cannot be established, and system wake-up needs to be achieved through a backup control path.

[0078] The second switch driving circuit is connected to the output terminal of the analog front-end chip. Through the second switch driving circuit, the driving control signal output by the analog front-end chip can be converted into a driving signal that can drive the second switch S2 to operate.

[0079] In this embodiment, the drive control signal can be output by the analog front-end chip and processed by the second switch drive circuit to drive the second switch S2 to close, thereby supplying power to the drive element. The drive control signal can be implemented in various ways, such as analog control signals, digital logic signals, or PWM (Pulse Width Modulation) signals. By setting the drive control signal path, the battery-side active wake-up function can be realized.

[0080] In this embodiment, the energy storage system is configured with a main control link (corresponding to the first switch S1 and the first switch drive circuit) and a backup control link (corresponding to the second switch S2 and the second switch drive circuit). When the first switch drive circuit is working normally, it is powered by a DC-DC converter and the drive element is powered by the first switch S1. When the first switch drive circuit fails, the analog front-end chip outputs a drive control signal to the second switch drive circuit, causing the second switch S2 to close, thereby enabling the drive element to receive battery power and driving the first controllable switch KM1 and the second controllable switch KM2 to close, making the battery module port energized. Through this backup control logic, it can be ensured that the energy storage system can still start the battery module when the external power supply is unavailable.

[0081] This embodiment constructs a redundant control structure based on an analog front-end chip within the battery module, enabling the energy storage system to form a dual control link structure. Specifically, when the main control link powered by the DC-DC converter fails, the analog front-end chip establishes a backup control link by outputting a drive control signal to the second switch drive circuit. This allows the drive element to close the first controllable switch KM1 and the second controllable switch KM2, thereby ensuring that the energy storage system can start up the battery module even when the energy storage converter's power supply is unavailable. This redundant control mechanism improves the reliability, operational flexibility, and safety of the energy storage system.

[0082] In some embodiments, the energy storage system may further include a battery monitoring unit (such as a CMU). The battery monitoring unit generates a wake-up signal upon detecting a fault in the first switch drive circuit. Upon receiving the wake-up signal, the analog front-end chip operates, providing drive control signals to the second switch drive circuit.

[0083] The battery monitoring unit can be a battery operation status management module installed in the energy storage system, used for monitoring, controlling, and managing the communication status of the battery modules. In this embodiment, the battery monitoring unit can provide auxiliary management of the internal control link of the battery module when it (i.e., the CMU itself) receives external power, and trigger a backup control mechanism when the main control link is abnormal. The battery monitoring unit can be implemented in various forms, such as the battery management system main control unit, battery control module, central control module, or system management controller. By setting up a battery monitoring unit, the operation status monitoring and fault response control of the energy storage system can be realized.

[0084] External power supply refers to the power supply method in which external devices of the energy storage system provide operating power to the battery monitoring unit. In this embodiment, the external power supply can include various forms such as an auxiliary power module, an external power adapter, or an independent power supply module. When the battery monitoring unit receives external power, it can start monitoring and control functions and participate in the wake-up control logic of the energy storage system. By setting the external power supply path, the energy storage system can still have the ability to start up when the energy storage converter cannot provide power.

[0085] A wake-up signal is a control signal output by the battery monitoring unit when it detects that the energy storage system meets external power supply conditions and that the main control link is abnormal. This signal triggers the analog front-end chip to enter the working state from standby. The wake-up signal can take various forms, including digital logic signals, level-triggered signals, communication control signals, or pulse-triggered signals. By setting the wake-up signal, the internal control circuitry of the battery module can still activate the backup control link when the main control link fails.

[0086] In this embodiment, after receiving a wake-up signal from the battery monitoring unit, the analog front-end chip switches from a low-power standby state to an operating state and begins outputting drive control signals to the second switch drive circuit. The switching of the analog front-end chip's operating mode can be achieved through its internal logic control module, power management module, and signal output module. This mechanism enables the battery module to achieve autonomous startup based on the battery-side power supply path.

[0087] The second switch driving circuit receives the drive control signal output by the analog front-end chip and converts it into a drive signal to drive the second switch S2. When the analog front-end chip is in operation, the second switch driving circuit outputs a drive signal to close the second switch S2, thereby enabling the drive element to be powered by the battery cell and driving the first controllable switch KM1 and the second controllable switch KM2 to close.

[0088] In this embodiment, the energy storage system adopts a control strategy in which the main control link and the backup control link work together. When the first switch drive circuit is working normally, the main control link powered by the DC-DC converter controls the battery module port to conduct. When the first switch drive circuit fails, the battery monitoring unit outputs a wake-up signal after obtaining external power supply, which enables the analog front-end chip to start and drive the second switch drive circuit, thereby establishing a power supply path on the battery side and ensuring that the battery module port can conduct normally.

[0089] This embodiment introduces a battery monitoring unit into the energy storage system and constructs a backup control link based on external power supply and analog front-end chip linkage, enabling the energy storage system to form a multi-path startup control mechanism. Specifically, when the main control link fails, the battery monitoring unit is powered by an external power source and outputs a wake-up signal, causing the analog front-end chip to start and provide drive control signals to the second switch drive circuit, thereby driving the first controllable switch KM1 and the second controllable switch KM2 to close, realizing the conduction of the battery module port. Through this redundant control mechanism, the operational reliability of the energy storage system can be significantly improved, adapting to startup requirements in multiple scenarios and enhancing the safety of the energy storage system.

[0090] In some embodiments, the first controllable switch KM1 and the second controllable switch KM2 can be electromagnetic switches.

[0091] In some embodiments, the driving element may be a driving coil.

[0092] In this embodiment, the first controllable switch KM1 and the second controllable switch KM2 can be implemented as electromagnetic switches. An electromagnetic switch is an electrical switching device that uses electromagnetic force to drive mechanical contacts to open or close. Electromagnetic switches can be implemented in various forms, such as DC contactors, power relays, holding relays, or magnetically latching relays. By setting the first controllable switch KM1 and the second controllable switch KM2 as electromagnetic switches, dual-terminal mechanical isolation between the positive and negative terminals of the battery module can be achieved, improving the reliability of electrical isolation and enabling it to withstand larger current surges.

[0093] An electromagnetic switch may include a drive coil, a magnetic circuit structure, a moving contact, a fixed contact, and a flexible mechanism. For example, when the drive coil is energized, it generates a magnetic field. This magnetic field drives the moving contact to move and make contact with the fixed contact, thus completing the circuit. When the drive coil is de-energized, the contact resets under the action of the flexible mechanism, thus disconnecting the circuit. In this embodiment, the electromagnetic switch is connected in series between the battery cell and the external connection terminal, so that the conduction state of the battery module port is determined by the state of the electromagnetic switch contacts. In the off state, the electromagnetic switch forms a clear physical isolation gap, effectively blocking the electrical connection between the battery cell and the external circuit, thereby meeting the electrical safety isolation requirements of the energy storage system. Compared to semiconductor switching devices, electromagnetic switches have the characteristics of low conduction loss, high withstand voltage, and high disconnection isolation capability.

[0094] In this embodiment, the on / off state of the electromagnetic switch is determined by whether its corresponding driving element is energized. In this embodiment, the driving element can be implemented as a driving coil. The driving coil is a winding structure used to generate electromagnetic driving force; when energized, it generates a magnetic field to drive the electromagnetic switch. The driving coil can be used in conjunction with the internal magnetic circuit structure of the electromagnetic switch. When the driving coil is powered, the magnetic field attracts the moving contact assembly, causing the electromagnetic switch to close; when the driving coil is de-energized, the magnetic field disappears, and the contacts open under the action of the elastic mechanism. The driving coil can be configured as a single-coil structure or a double-coil structure, and can be combined with a holding drive method to achieve energy-saving control.

[0095] The drive coil can consist of wire windings and insulation structures, and its electrical parameters can include coil resistance, rated drive voltage, and drive current. In this embodiment, the drive coil can be a DC drive coil, a pulse drive coil, or a magnetic latching drive coil. By rationally designing the drive coil parameters, it can be ensured that the electromagnetic switch has stable engagement and reliable disengagement capabilities under different operating conditions.

[0096] In this embodiment, the power supply state of the drive coil is determined by the energy storage system control link. This embodiment uses electromagnetic switches KM1 and KM2 as the first controllable switch and the drive coil as the actuating drive element, making the conduction state of the battery module port dependent on the power supply state of the drive coil. When the drive coil is energized, the electromagnetic switch closes, and the battery module can establish an electrical connection with the energy storage system; when the drive coil is de-energized, the electromagnetic switch opens, and the battery module port is in an electrically isolated state. By linking the power supply path of the drive coil with the power supply state and control signals of the energy storage system, multi-level safety control of the battery port's energized state can be achieved, thereby improving the safety and operational reliability of the energy storage system.

[0097] See Figure 5 , Figure 5 This is a structural block diagram of a battery module provided in an embodiment of this application.

[0098] This application also provides a battery module for use in an energy storage system, which further includes an energy storage converter and a DC-DC converter.

[0099] The battery module includes a battery cell, a first connection terminal, a second connection terminal, a first controllable switch KM1, a second controllable switch KM2, and a switch control unit. The positive terminal of the battery cell is connected to the first connection terminal via the first controllable switch KM1, and the negative terminal of the battery cell is connected to the second connection terminal via the second controllable switch KM2. The switch control unit controls the first controllable switch KM1 and the second controllable switch KM2. The first terminal of the energy storage converter is used to connect to AC power, the positive terminal of the second terminal of the energy storage converter is connected to the first connection terminal, and the negative terminal of the second terminal of the energy storage converter is connected to the second connection terminal. The first terminal of the DC converter is connected to the second terminal of the energy storage converter, and the second terminal of the DC converter is connected to the power supply terminal of the switch control unit.

[0100] In some embodiments, the switch control unit may include a first switch S1 and a first switch drive circuit. A first terminal of the first switch S1 is connected to a second terminal of the DC-DC converter, and the second terminal of the first switch S1 is connected to drive elements for a first controllable switch KM1 and a second controllable switch KM2. The drive elements are used to drive the first controllable switch KM1 and the second controllable switch KM2 to conduct in response to the first switch S1 being turned on. The first switch drive circuit is connected to the second terminal of the DC-DC converter and is used to drive the first switch S1.

[0101] In some embodiments, the battery module may further include an analog front-end chip, a second switch S2, and a second switch driving circuit. The power supply terminal of the analog front-end chip is connected to the battery cell. The positive and negative terminals of the first terminal of the second switch S2 are connected to the positive and negative terminals of the battery cell, respectively. The second terminal of the second switch S2 is connected to driving elements for the first controllable switch KM1 and the second controllable switch KM2. The driving elements are used to drive the first controllable switch KM1 and the second controllable switch KM2 to conduct in response to the second switch S2 being turned on. The second switch driving circuit is connected to the output terminal of the analog front-end chip to drive the second switch S2 according to the driving control signal output by the analog front-end chip.

[0102] like Figure 3 and Figure 4 As shown in the embodiment of this application, an energy storage system is also provided, including a switch box, an energy storage converter, and at least two stacked battery modules. The at least two battery modules include a first battery module to an Nth battery module connected in sequence. The switch box includes a DC-DC converter, where N is an integer greater than 1.

[0103] The battery module includes a battery cell, a first connection terminal, a second connection terminal, a first controllable switch KM1, a second controllable switch KM2, and a switch control unit. The positive terminal of the battery cell is connected to the first connection terminal through the first controllable switch KM1, and the negative terminal of the battery cell is connected to the second connection terminal through the second controllable switch KM2. The switch control unit controls the first controllable switch KM1 and the second controllable switch KM2.

[0104] The first terminal of the energy storage converter is used to connect to AC power. The positive terminal of the second terminal of the energy storage converter is connected to the first connection terminal of the first battery module, and the negative terminal of the second terminal of the energy storage converter is connected to the second connection terminal of the Nth battery module.

[0105] The first terminal of the DC-DC converter is connected to the second terminal of the energy storage converter, and the second terminal of the DC-DC converter is connected to the power supply terminal of the switch control unit.

[0106] The switch box can be an integrated electrical control and protection structure installed in the energy storage system, used to house power management, electrical isolation, and control power supply functional modules. In this embodiment, a DC-DC converter is installed inside the switch box. The switch box can be implemented as a modular control box, power control box, or power management box, etc. By centrally installing the control power supply modules inside the switch box, the power management and control functions of the energy storage system can be integrated, and a unified control power supply path can be provided for each battery module.

[0107] Stacked at least two battery modules refer to an energy storage structure in which multiple battery modules are arranged sequentially along the mechanical structure direction or the electrical connection direction and form an electrical connection relationship. In this embodiment, the battery modules are connected in sequence from the first battery module to the Nth battery module to form an energy storage system-level energy storage voltage output structure. The stacked structure can include various forms such as a vertical stacked structure, a horizontal series structure, or a modular combination structure. By adopting a stacked structure, energy storage capacity expansion and energy storage system voltage level adjustment can be achieved, and the modular expansion requirements of user energy storage systems can be met.

[0108] In this embodiment, the positive terminal of the second end of the energy storage converter is connected to the first connection terminal of the first battery module, and the negative terminal of the second end of the energy storage converter is connected to the second connection terminal of the Nth battery module, thereby forming a multi-battery module series connection structure. This connection method enables the energy storage converter to establish a unified electrical connection path with the stacked battery modules and form a system-level energy storage voltage output structure. Through this connection structure, the voltage superposition output of multiple battery modules can be realized.

[0109] In the embodiment of the present application, the energy storage system includes a switch box, a power conversion system (PCS), and at least two battery modules arranged in a stacked manner. A first controllable switch KM1 and a second controllable switch KM2 are arranged inside each battery module, which are respectively used to control the electrical connection state between the positive electrode of the battery cell and the first connection terminal, and between the negative electrode of the battery cell and the second connection terminal. The DC side of the power conversion system forms a power energy exchange path through the first connection terminal of the first battery module and the second connection terminal of the Nth battery module, and provides working power for the switch control units of each battery module through the DC converter arranged in the switch box. When the power conversion system is connected to alternating current and in an operable state, the DC converter obtains electric energy from the DC side of the power conversion system and supplies power to the switch control units of each battery module, and the switch control units drive the first controllable switch KM1 and the second controllable switch KM2 to close, so that each battery module forms a complete electrical connection path, and the normal operation of the energy storage system is realized. When the power conversion system is not connected or the energy storage system is not completely assembled, the DC converter cannot supply power to the switch control units, the first controllable switch KM1 and the second controllable switch KM2 of each battery module remain disconnected, so that the external terminals of the battery module are in an unpowered state, thereby realizing the safety isolation control of the battery module ports.

[0110] In this embodiment, by arranging the first controllable switch KM1 and the second controllable switch KM2 in each battery module, and arranging the DC converter to provide a power supply path for the switch control units, the linkage control between the charged state of the battery module ports and the power supply state of the power conversion system is realized, so that the battery modules establish electrical connection only when the energy storage system meets the operating conditions, which improves the operation safety of the energy storage system. By sequentially stacking and connecting at least two battery modules, and using the DC side of the power conversion system to uniformly establish a power supply link, centralized control and hierarchical isolation control of multiple battery modules are realized, thereby improving the structural scalability and operation reliability of the energy storage system. By using the DC converter arranged in the switch box to supply power for the switch control units, automatic management of the charged state of the battery module ports is realized, thereby reducing the complexity of manual operation and the risk of human misoperation. By keeping the controllable switches disconnected when the energy storage system is not completely installed or the power conversion system does not operate normally, electrical isolation of the battery module ports is realized, thereby reducing the safety risks of battery short circuit, arc flashover and electric shock. Aiming at the problems that battery ports are easy to be charged, the isolation operation is complicated and the safety risk is high when the stacked energy storage system is in installation, maintenance or abnormal operation state, this embodiment adopts the concept of arranging controllable switches at the battery module ports and performing linkage control through DC converter power supply, thereby realizing automatic safety management of the port charged state of the multi-module energy storage system and improving the system reliability and operation flexibility.

[0111] In some embodiments, the switch control unit may include a first switch S1 and a first switch drive circuit. A first terminal of the first switch S1 is connected to a second terminal of the DC-DC converter, and the second terminal of the first switch S1 is connected to drive elements for a first controllable switch KM1 and a second controllable switch KM2. The drive elements are used to drive the first controllable switch KM1 and the second controllable switch KM2 to conduct in response to the first switch S1 being turned on. The first switch drive circuit is connected to the second terminal of the DC-DC converter and is used to drive the first switch S1.

[0112] Still as Figure 3 and Figure 4 As shown, in some embodiments, the switch box may include a DC-DC converter, a circuit breaker CF, and a pre-charge relay KM. The first terminal of the circuit breaker CF is connected to the first terminal of the DC-DC converter, and the second terminal of the circuit breaker CF is used to connect to the second terminal of the energy storage converter. The positive terminal of the second terminal of the energy storage converter is connected to the first connection terminal of the first battery module through the circuit breaker CF, and the negative terminal of the second terminal of the energy storage converter is connected to the second connection terminal of the Nth battery module through the circuit breaker CF. The pre-charge relay KM is connected in series between the first terminal of the circuit breaker CF and the first connection terminal of the first battery module, or the pre-charge relay KM is connected in series between the first terminal of the circuit breaker CF and the second connection terminal of the Nth battery module.

[0113] The precharge relay KM is set as the switching device for the precharge branch, which is connected across the two ends of the circuit breaker CF. It is used to establish a current-limiting precharge path when the circuit breaker CF is open, so that the DC side of the energy storage converter and the battery module can be precharged. After the precharge is completed, the circuit breaker CF is closed to establish the main current path, and the precharge relay KM is opened or kept open.

[0114] As an example, during the power-on startup phase of the energy storage system, the circuit breaker CF remains open, and the pre-charge relay KM controls the pre-charge branch to conduct, enabling the DC side of the energy storage converter to gradually establish voltage balance with the battery module through the current-limiting channel, thereby suppressing the surge current caused by the instantaneous charging of the bus capacitor on the DC side of the energy storage converter; when the voltage difference between the DC side voltage of the energy storage converter and the battery side voltage is detected to meet the preset threshold condition, the circuit breaker CF is controlled to close to establish the main current path, and the pre-charge relay KM is controlled to disconnect the pre-charge branch, thereby completing the switch from current-limited pre-charge to main circuit power supply.

[0115] like Figure 4 As shown, in some embodiments, the switch box may further include a battery monitoring unit. The battery monitoring unit generates a wake-up signal upon detecting a fault in the first switch drive circuit.

[0116] In some embodiments, the DC-DC converter circuit, the circuit breaker CF, and the battery monitoring unit can be integrated. As an example, the DC-DC converter circuit, the circuit breaker CF, and the battery monitoring unit can be integrated within a switch box.

[0117] See Figure 6 , Figure 6 This is a startup flowchart of an energy storage system provided in an embodiment of this application.

[0118] The startup process includes, for example, the following steps.

[0119] Assemble one or more battery modules, a switch box, and a base into an energy storage system. Before the energy storage system is fully assembled, the positive and negative terminals of the battery modules have no voltage. After the energy storage system is assembled, determine whether to connect it to an energy storage converter.

[0120] When the energy storage converter is connected, the DC-DC converter is used to power the first switch drive circuit (such as the S1 drive) and control the first switch S1 to close. The drive element is powered by the DC-DC converter, and the positive and negative terminals of the battery module have voltage, so the energy storage system can start and operate normally.

[0121] Without connecting the energy storage converter, determine whether an external power supply is available. If an external power supply is available, it powers the second switch drive circuit (e.g., S2 drive) and controls the second switch S2 to close. The drive element is powered by the battery cell, and the positive and negative terminals of the battery module have voltage, allowing the energy storage system to start and operate normally. If no external power supply is available, the positive and negative terminals of the battery module have no voltage.

[0122] The above embodiments, after the energy storage system is assembled, support a dual-start mode with both external energy storage converter and external power supply. After the first switch S1 or the second switch S2 is closed, the drive element is energized, and only then do the positive and negative terminals of the battery module become energized. This application's embodiments design a redundant control start-up scheme for the energy storage system. After the energy storage system is installed, it can be started up in both black-start mode and energy storage converter power supply mode. This redundant control enriches the application scenarios of the energy storage system and improves its reliability, safety, and flexibility.

[0123] It is understood that the specific examples in this application are only intended to help those skilled in the art better understand the implementation of this application, and are not intended to limit the scope of protection of this application.

[0124] It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of this application.

[0125] It is understood that the various implementation methods described in this application can be implemented individually or in combination, and this application does not limit them.

[0126] Unless otherwise stated, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "one or more" as used in this application includes any and all combinations of one or more of the associated listed items. The singular forms "a," "the," and "the" as used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0127] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0128] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes and beneficial effects of the embodiments described above can be referred to the corresponding processes and beneficial effects in other embodiments, and will not be repeated here.

[0129] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple 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 between apparatuses or units may be electrical, mechanical, or other forms.

[0130] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the technical solution in this application, depending on actual needs.

[0131] In addition, 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.

[0132] If a function 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 part of the technical solution, can be embodied in the form of a software product. The 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.) 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.

[0133] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An energy storage system, characterized by, include: At least one battery module, the battery module including a battery cell, a first connection terminal, a second connection terminal, a first controllable switch, a second controllable switch and a switch control unit, the positive terminal of the battery cell being connected to the first connection terminal through the first controllable switch, the negative terminal of the battery cell being connected to the second connection terminal through the second controllable switch, and the switch control unit controlling the first controllable switch and the second controllable switch; An energy storage converter, wherein a first terminal of the energy storage converter is used to connect to AC power, the positive terminal of the second terminal of the energy storage converter is connected to the first connection terminal, and the negative terminal of the second terminal of the energy storage converter is connected to the second connection terminal; A DC-DC converter, wherein the first end of the DC-DC converter is connected to the second end of the energy storage converter, and the second end of the DC-DC converter is connected to the power supply terminal of the switch control unit.

2. The energy storage system of claim 1, wherein, The energy storage system also includes: A circuit breaker, wherein the first end of the circuit breaker is connected to the first end of the DC converter, and the second end of the circuit breaker is used to connect to the second end of the energy storage converter. The positive and negative terminals of the second end of the energy storage converter are connected to the first connection terminal and the second connection terminal through the circuit breaker.

3. The energy storage system of claim 1, wherein, The switch control unit includes: At least one first switch is connected in series with a driving element at the second terminal of the DC-DC converter, and the driving element is used to drive the first controllable switch and the second controllable switch to turn on in response to the at least one first switch being turned on. A first switch driving circuit is connected to the second terminal of the DC-DC converter and is used to drive the first switch.

4. The energy storage system of claim 3, wherein, The battery module also includes: An analog front-end chip, wherein the power supply terminal of the analog front-end chip is connected to the battery unit; At least one second switch is connected in series with the driving element between the positive and negative terminals of the battery cell. The driving element is used to drive the first controllable switch and the second controllable switch to turn on in response to the second switch being turned on. A second switch driving circuit is connected to the output terminal of the analog front-end chip to drive the second switch according to the driving control signal output by the analog front-end chip.

5. The energy storage system according to claim 4, characterized in that, The analog front-end chip is used to provide the drive control signal to the second switch drive circuit in the event of a failure in the first switch drive circuit.

6. The energy storage system according to claim 5, characterized in that, The energy storage system also includes a battery monitoring unit, which generates a wake-up signal when it detects a fault in the first switch drive circuit; the analog front-end chip operates after receiving the wake-up signal and provides the drive control signal to the second switch drive circuit.

7. The energy storage system according to claim 3, characterized in that, The first controllable switch and the second controllable switch are electromagnetic switches, and the driving element is a driving coil.

8. A battery module, characterized in that, It is applied to an energy storage system, which further includes an energy storage converter and a DC-DC converter; The battery module includes a battery cell, a first connection terminal, a second connection terminal, a first controllable switch, a second controllable switch, and a switch control unit. The positive terminal of the battery cell is connected to the first connection terminal via the first controllable switch, and the negative terminal of the battery cell is connected to the second connection terminal via the second controllable switch. The switch control unit controls the first controllable switch and the second controllable switch. The first terminal of the energy storage converter is used to connect to AC power, the positive terminal of the second terminal of the energy storage converter is connected to the first connection terminal, and the negative terminal of the second terminal of the energy storage converter is connected to the second connection terminal. The first terminal of the DC-DC converter is connected to the second terminal of the energy storage converter, and the second terminal of the DC-DC converter is connected to the power supply terminal of the switch control unit.

9. The battery module according to claim 8, characterized in that, The switch control unit includes: A first switch, wherein a first end of the first switch is connected to a second end of the DC-DC converter, and the second end of the first switch is connected to a drive element for the first controllable switch and the second controllable switch, the drive element being used to drive the first controllable switch and the second controllable switch to conduct in response to the first switch being turned on; A first switch driving circuit is connected to the second terminal of the DC-DC converter and is used to drive the first switch.

10. The battery module according to claim 9, characterized in that, The battery module also includes: An analog front-end chip, wherein the power supply terminal of the analog front-end chip is connected to the battery unit; The second switch has its positive and negative terminals connected to the positive and negative terminals of the battery cell, respectively, and its second terminal connected to a driving element for the first and second controllable switches. The driving element is used to drive the first and second controllable switches to conduct in response to the second switch being turned on. A second switch driving circuit is connected to the output terminal of the analog front-end chip to drive the second switch according to the driving control signal output by the analog front-end chip.

11. An energy storage system, comprising a switch box, an energy storage converter, and at least two stacked battery modules, the at least two battery modules comprising a first battery module to an Nth battery module connected in sequence, the switch box including a DC-DC converter, where N is an integer greater than 1; The battery module includes a battery cell, a first connection terminal, a second connection terminal, a first controllable switch, a second controllable switch, and a switch control unit. The positive terminal of the battery cell is connected to the first connection terminal through the first controllable switch, and the negative terminal of the battery cell is connected to the second connection terminal through the second controllable switch. The switch control unit controls the first controllable switch and the second controllable switch. The first end of the energy storage converter is used to connect to AC power, the positive terminal of the second end of the energy storage converter is connected to the first connection terminal of the first battery module, and the negative terminal of the second end of the energy storage converter is connected to the second connection terminal of the Nth battery module. The first terminal of the DC-DC converter is connected to the second terminal of the energy storage converter, and the second terminal of the DC-DC converter is connected to the power supply terminal of the switch control unit.

12. The energy storage system according to claim 11, characterized in that, The switch control unit includes: A first switch, wherein a first end of the first switch is connected to a second end of the DC-DC converter, and the second end of the first switch is connected to a drive element for the first controllable switch and the second controllable switch, the drive element being used to drive the first controllable switch and the second controllable switch to conduct in response to the first switch being turned on; A first switch driving circuit is connected to the second terminal of the DC-DC converter and is used to drive the first switch.

13. The energy storage system according to claim 12, characterized in that, The switch box includes the DC converter, circuit breaker, precharge relay, and battery monitoring unit; The first terminal of the circuit breaker is connected to the first terminal of the DC converter, and the second terminal of the circuit breaker is used to connect to the second terminal of the energy storage converter. The positive terminal of the second terminal of the energy storage converter is connected to the first connection terminal of the first battery module through the circuit breaker, and the negative terminal of the second terminal of the energy storage converter is connected to the second connection terminal of the Nth battery module through the circuit breaker. The precharge relay is connected in series between the first end of the circuit breaker and the first connection terminal of the first battery module, or the precharge relay is connected in series between the first end of the circuit breaker and the second connection terminal of the Nth battery module. The battery monitoring unit generates a wake-up signal when it detects a fault in the first switch drive circuit.

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