Energy storage system and power plant

Abstract

The application discloses an energy storage system and a power station, and relates to the technical field of energy storage systems, which comprises at least two battery modules, an interface assembly and a battery management system. A battery information collector is arranged in each battery module, and the battery information collector is used for collecting the monomer parameters of the battery module itself; the interface assembly is used for connecting or disconnecting the at least two battery modules, so that the number of the battery modules connected to the energy storage system is variable; once any battery module is connected to the energy storage system, the battery module actively sends the monomer parameters thereof; a controller in the battery management system is connected with the battery information collector, and the controller is used for receiving each monomer parameter, calculating the overall parameters of the energy storage system according to the monomer parameters, judging whether the number of the battery modules is changed according to the overall parameters, and adjusting the control parameters of the battery management system according to the overall parameters when the number of the battery modules is changed. The control logic is simplified, and the battery management system is convenient for accurately controlling the state of the entire energy storage system.

Description

Technical Field

[0001] This application relates to the field of batteries, and more specifically to an energy storage system and a power station. Background Technology

[0002] With changes in the international situation and the increasing reliance on energy and the need for energy storage, energy storage systems have emerged. For regions lacking oil and coal resources, if they possess natural advantages in sunlight, this can serve as a substitute for energy supplementation. Currently, residential energy storage has become a crucial energy supply and storage method, significantly contributing to reducing users' electricity costs. Residential energy storage systems are increasingly becoming an important subsequent link in energy production. Developing residential energy storage systems is beneficial for both alleviating energy shortages and reducing operating costs. In residential energy storage systems, there are often situations requiring changes in the number of battery modules. However, related technologies cannot integrate the parameter information of different battery modules, leading to complex and inaccurate control logic. Summary of the Invention

[0003] This application is made to address at least one of the aforementioned problems. According to a first aspect of this application, an energy storage system is provided, comprising: at least two battery modules, an interface component, and a battery management system. Each battery module is equipped with a battery information collector for collecting individual parameters of the battery module itself. The interface component is configured to connect at least two battery modules, allowing the number of battery modules connected to the energy storage system to be variable. Once any battery module is connected to the energy storage system, it actively transmits its individual parameters. The battery management system includes a controller connected to the battery information collector, and the controller is configured to: receive each individual parameter, calculate the overall parameters of the energy storage system based on the individual parameters, determine whether the number of battery modules has changed based on the overall parameters, and adjust the control parameters of the battery management system based on the overall parameters when the number of battery modules changes.

[0004] In one embodiment of this application, each of the interface components includes a first interface and a second interface; both the first interface and the second interface are connected to the controller; wherein the first interface is used to connect to the battery in the battery module, and the second interface is used to connect to the battery information collector in the battery module.

[0005] In one embodiment of this application, the battery information collector transmits the collected individual cell parameters to the controller via the second interface.

[0006] In one embodiment of this application, at least two of the battery information collectors are connected in series via corresponding second interfaces; the controller includes a first control interface and a second control interface; one end of the series-connected battery information collectors is connected to the first control interface, and the other end is connected to the second control interface.

[0007] In one embodiment of this application, the battery management system further includes a DC-DC converter; the DC-DC converter is used to convert the DC power output by the energy storage system from a first voltage to a second voltage to power the controller; wherein the first voltage is greater than the second voltage.

[0008] In one embodiment of this application, the battery management system further includes a trip unit connected between the battery module and the DC-DC converter; when the trip unit is closed, the battery module supplies power to the controller through the DC-DC converter; and the controller is also connected to the trip unit, and the controller is further configured to control the trip unit to switch from a closed state to an open state according to the control parameters.

[0009] In one embodiment of this application, the energy storage system further includes an inverter; the battery management system further includes: a pre-charge resistor and a pre-charge contactor connected in series; wherein the pre-charge resistor is connected to the trip unit, and the pre-charge contactor is connected to the inverter; and the controller is also connected to the pre-charge contactor, and the controller is further configured to: control the pre-charge contactor to close when the overall voltage in the overall parameters is less than a preset threshold, and control the pre-charge contactor to open when the overall voltage in the overall parameters is not less than the preset threshold.

[0010] In one embodiment of this application, the battery management system further includes a main positive contactor and a main negative contactor; wherein, the trip unit is connected to the positive output terminal of the battery module, the main positive contactor is connected between the trip unit and the inverter, and the main positive contactor is connected in parallel with the pre-charge resistor and the pre-charge contactor; the main negative contactor is connected to the negative output terminal of the battery module, and the inverter is also connected to the negative output terminal of the battery module through the main negative contactor; the controller is connected to both the main positive contactor and the main negative contactor, and the controller is further configured to: control the pre-charge contactor and the main negative contactor to close, and control the main positive contactor to close when the overall voltage in the overall parameters is not less than the preset threshold.

[0011] In one embodiment of this application, the controller is further configured to: determine whether the energy storage system has experienced a first fault type based on the overall parameters, and when the energy storage system experiences the first fault type, control both the main positive contactor and the main negative contactor to disconnect.

[0012] In one embodiment of this application, the controller is further configured to: determine whether the energy storage system has a second fault type based on the overall parameters, and control the trip unit to disconnect when the energy storage system has the second fault type.

[0013] In one embodiment of this application, the controller is provided with a shunt meter, which is connected between the DC-DC converter and the controller, and the shunt meter is also connected between the negative terminal of the battery module and the main negative contactor to detect the current information output by the DC-DC converter.

[0014] In one embodiment of this application, the battery management system further includes a communication module, which is communicatively connected to both the controller and the inverter. The communication module is used to transmit one or more of the individual cell parameters, the overall parameters, and the control parameters to the outside world, and is also used to receive control commands from the outside world and transmit the control commands to the controller.

[0015] In one embodiment of this application, the individual parameters include the capacity, voltage, current, state of charge, or temperature of each battery module, and the overall parameters include the overall capacity, overall voltage, overall current, overall state of charge, or overall temperature of the energy storage system.

[0016] In one embodiment of this application, the individual parameters include the voltage parameters of each battery module, and the overall parameters include the expected total voltage parameters of the energy storage system calculated based on the voltage parameters collected by each battery information collector; the controller is further configured to detect the actual total voltage parameters of the energy storage system and compare the expected total voltage parameters with the actual total voltage parameters to determine whether a battery module has malfunctioned.

[0017] According to a second aspect of this application, a power station is provided, the power station including any of the above-described energy storage systems.

[0018] According to the energy storage system and power station provided in the embodiments of this application, by setting an interface component, at least two battery modules can be connected in a way that allows for switching, so that the number of battery modules connected to the energy storage system is variable. Once any battery module is connected to the energy storage system, it actively transmits its own individual parameters. All battery modules connected to the energy storage system share a battery management system, which includes a controller. Each battery information collector is connected to the controller, enabling the controller to receive individual parameters collected by each battery information collector for each battery module. The controller can then calculate the overall parameters of the energy storage system based on the received individual parameters, determine whether the number of battery modules connected to the energy storage system has changed based on the overall parameters, and adjust the control parameters of the battery management system according to the overall parameters when the number of battery modules connected to the energy storage system changes. Compared with existing home energy storage systems, this application can calculate the overall parameters based on individual parameters, determine whether the number of battery modules connected to the energy storage system has changed based on the overall parameters, and adjust the control parameters of the battery management system according to the overall parameters when the number of battery modules changes. This allows the overall parameters of the energy storage system to be obtained by integrating the individual parameter information of different battery modules, and the control parameters of the battery management system to be adaptively adjusted based on the overall parameters, simplifying the complex control logic and facilitating the battery management system to accurately control the state of the entire energy storage system. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic block diagram of an energy storage system according to an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of the present invention, and not all of the embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described herein, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of the present invention.

[0022] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0023] It should be understood that the invention can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0024] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0025] To fully understand this invention, a detailed structure will be presented in the following description to illustrate the technical solution proposed by this invention. Optional embodiments of the invention are described in detail below; however, in addition to these detailed descriptions, the invention may have other embodiments.

[0026] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0027] This application provides an energy storage system, referencing... Figure 1 The energy storage system includes at least two battery modules, an interface component, and a battery management system. Each battery module is equipped with a battery information collector, which collects the individual parameters of the battery module. The interface component allows for the connection and disconnection of at least two battery modules, enabling a variable number of battery modules to be connected to the energy storage system. Once connected to the energy storage system, any battery module actively transmits its individual parameters. The battery management system includes a controller connected to the battery information collector. The controller is used to: receive the parameters of each individual battery module; calculate the overall parameters of the energy storage system based on the received individual parameters; determine whether the number of battery modules has changed based on the overall parameters; and adjust the control parameters of the battery management system according to the overall parameters when the number of battery modules changes.

[0028] In the above scheme, by setting an interface component, at least two battery modules can be connected and disconnected, allowing the number of battery modules connected to the energy storage system to be variable. Once any battery module is connected to the energy storage system, it actively transmits its individual parameters. All battery modules connected to the energy storage system share a battery management system, which includes a controller. Each battery information collector is connected to the controller, enabling the controller to receive individual parameters collected by each battery information collector for each battery module. The controller can then calculate the overall parameters of the energy storage system based on the received individual parameters, determine whether the number of battery modules connected to the energy storage system has changed based on the overall parameters, and adjust the control parameters of the battery management system according to the overall parameters when the number of battery modules connected to the energy storage system changes. Compared to existing home energy storage systems, this application can calculate the overall parameters based on individual parameters, determine whether the number of battery modules connected to the energy storage system has changed based on the overall parameters, and adjust the control parameters of the battery management system according to the overall parameters when the number of battery modules changes. This allows the overall parameters of the energy storage system to be obtained by integrating the individual parameter information of different battery modules, and the control parameters of the battery management system to be adaptively adjusted based on the overall parameters, simplifying the complex control logic and facilitating the battery management system to accurately control the state of the entire energy storage system. The following section provides a detailed explanation of each of the above steps in conjunction with the accompanying drawings.

[0029] When setting up an energy storage system, at least two battery modules can be connected, and each battery module can serve as an energy storage device. Specifically, the number of battery modules connected to the energy storage system can be two, three, four, ten, or more. Multiple battery modules can be connected in parallel or series, which can increase the capacity, output voltage, or output current of the energy storage system. Specifically, when battery modules are connected in series, the series connection increases the voltage, thereby increasing the output voltage of the energy storage system; when battery modules are connected in parallel, the parallel connection increases the current, thereby increasing the capacity of the energy storage system. In some embodiments, reference is made to... Figure 1 Multiple battery modules can be connected in series. It should be understood that... Figure 1 The series connection method shown is not limited to the only implementation method of this application embodiment; other implementation methods can also be used. Additionally, a structure with a heating film function can be provided in each battery module to adjust the temperature of each battery module.

[0030] Continue to refer to Figure 1Each battery module is equipped with a battery information acquisition unit. This unit connects to the controller in the battery management system to transmit the individual battery module parameters it collects to the controller. The battery information acquisition unit may include a voltage acquisition unit for collecting the individual voltage parameters of the battery module, a current acquisition module for collecting the individual current parameters, a temperature acquisition module for collecting the individual temperature parameters, and a state-of-charge (SOC) acquisition module for collecting the individual SOC parameters. The controller connects to the battery information acquisition unit, enabling it to receive various types of individual parameters collected by the unit. This allows for bidirectional command transmission between the controller and the battery information acquisition unit, reading individual parameters such as voltage, current, SOC, capacity, and temperature of the battery modules. Simultaneously, the controller can also send commands to the battery information acquisition unit to perform functions such as equalization control.

[0031] When connecting each battery module to the energy storage system, an interface component is provided within the system. This component allows for the on / off connection of at least two battery modules, thus enabling a variable number of modules to be connected. Specifically, each battery module connects to the interface component to access the system. The system, through this interface component, can connect at least two battery modules, allowing for a variable number of modules to be connected. Once connected, each battery module actively transmits its individual parameters, allowing the controller to understand these parameters. The interface component can use, but is not limited to, plug-in interfaces to connect to the battery modules, facilitating their integration into the energy storage system.

[0032] For example, each interface component may include a first interface and a second interface, both of which are connected to the controller. The first interface is used to connect to the batteries in the battery module, and the second interface is used to connect to the battery information collector in the battery module. Each battery module is connected to the energy storage system through two interfaces, thus facilitating the series-parallel connection between batteries in different battery modules, which is independent of the series-parallel connection between the battery information collectors in different battery modules. That is, when batteries in different battery modules are connected in series or parallel to achieve voltage or current boosting, the series-parallel connection of the battery information collectors can be disregarded. Of course, in other embodiments, one interface can be provided for each battery module, through which both the batteries and the battery information collector in that module are connected to the controller of the energy storage system. For example, wiring can be provided in this single interface for both the battery information collector and the batteries, ensuring that the series-parallel connection of the batteries and the series-parallel connection of the battery information collector are independent of each other.

[0033] For example, the battery information collector transmits the collected individual cell parameters to the controller through the second interface. Specifically, after connecting the battery of a battery module to the first interface and the battery information collector of that battery module to the second interface, the battery information collector can actively send the collected individual cell parameters of the battery module to the controller through the second interface.

[0034] There are several ways to connect a battery information collector to a battery management system. For example, refer to... Figure 1 At least two battery information collectors are connected in series via corresponding second interfaces; the controller includes a first control interface and a second control interface; one end of each series-connected battery information collector is connected to the first control interface, and the other end is connected to the second control interface. Specifically, battery information collectors from at least two battery modules can be connected in series, and in some cases, all second interfaces can be connected in series. All battery information collectors in the energy storage system are connected in series sequentially, end to end, according to a method such as, but not limited to, location, distance, etc. Then, the series-connected battery information collectors are connected to the controller.

[0035] For example, such as Figure 1As shown, the controller can include a first control interface and a second control interface. One end of a series-connected battery information collector can be connected to the first control interface, and the other end to the second control interface. By employing a double-loop daisy-chain communication method between the battery information collectors, the controller can read the information collected by each battery information collector through either the first or second control interface. Therefore, when communication is lost (communication is interrupted) near the negative terminal of the battery module (second control interface), the controller can still read the battery information collector through the daisy-chain communication near the positive terminal of the energy storage system (first control interface). This application innovatively uses daisy-chain loop communication in the energy storage system. When different numbers of battery modules are stacked, the battery information collector can be read from different directions of the first or second control interface to obtain the cell information of each battery module, resulting in higher reliability.

[0036] It should be understood that the way the battery information collector is connected to the controller is not limited to the method shown above; other methods may also be used.

[0037] When implementing communication between the battery information collector and the controller in the battery module, refer to... Figure 1 This allows the controller in the battery management system to be connected to the battery information collector. The controller is used to: receive individual cell parameters collected by each battery information collector; calculate the overall parameters of the energy storage system based on the individual cell parameters; determine whether the number of battery modules has changed based on the overall parameters; and adjust the control parameters of the battery management system according to the overall parameters when the number of battery modules changes.

[0038] In other words, the controller, acting as the logic processing device in the battery management system, can calculate the overall parameters of the energy storage system based on the individual cell parameters collected by each battery information collector. For example, it can calculate the overall voltage of the energy storage system based on the voltage in the individual cell parameters, and the overall current of the energy storage system based on the current in the individual cell parameters. When the battery modules are connected to the interface components, the controller, after receiving the individual cell parameters collected by the battery information collector, can construct the series-parallel topology of the batteries in different battery modules, and calculate the overall parameters of the energy storage system based on the series-parallel topology of the batteries in the battery modules and the individual cell parameters of each battery module.

[0039] When determining whether the number of battery modules has changed based on overall parameters, and adjusting the control parameters of the battery management system (BMS) based on these overall parameters when the number of battery modules changes, if subsequent applications detect differences in the overall parameters of the energy storage system compared to previous times, it indicates that the number of battery modules connected to the energy storage system may have changed. For example, when battery modules are connected in series, if the overall voltage of the energy storage system changes, it indicates that the number of battery modules connected to the energy storage system has changed. Specifically, if the overall voltage increases, it indicates that the number of battery modules has increased; if the overall voltage decreases, it indicates that the number of battery modules has decreased. When battery modules are connected in parallel, if the overall current of the energy storage system changes, it indicates that the number of battery modules connected to the energy storage system has changed. Specifically, if the overall current increases, it indicates that the number of battery modules has increased; if the overall current decreases, it indicates that the number of battery modules has decreased. When a change in the number of battery modules is detected, the controller can adjust the control parameters of the BMS based on the overall parameters. This integrates the individual parameter information of different battery modules to obtain the overall parameters of the energy storage system, and adaptively adjusts the control parameters of the BMS based on these overall parameters, simplifying the complex control logic and facilitating accurate control of the entire energy storage system's state by the BMS.

[0040] For example, refer to Figure 1 The battery management system may also include a DC-DC converter, or DC-DC unit. The DC-DC converter acts as a transformer, converting high-voltage DC to low-voltage DC. Specifically, the DC-DC converter transforms the DC output from the energy storage system from a first voltage to a second voltage to power the controller. The first voltage is greater than the second voltage, thus enabling the controller to operate using a low-voltage power supply.

[0041] For specific connection details, please refer to... Figure 1 The battery module includes a positive output terminal and a negative output terminal. The DC-DC converter has two input ports: a positive input port and a negative output port. The positive input port of the DC-DC converter is connected to the positive output terminal of the battery module via a wire, and the negative input port of the DC-DC converter is connected to the negative output terminal of the battery module via a wire. The DC-DC converter also has positive and negative output ports. The positive output port of the DC-DC converter is connected to the positive pin of the controller, and the negative output port of the DC-DC converter is connected to the negative pin of the controller, thereby providing low-voltage power to the controller.

[0042] For example, such as Figure 1As shown, the battery management system may also include a trip unit connected between the battery module and the DC-DC converter. When the trip unit is closed, the battery module supplies power to the controller through the DC-DC converter. The controller is also connected to the trip unit and is used to control the trip unit to switch from a closed to an open state based on control parameters. Since the battery module cannot supply power to the DC-DC converter when the trip unit is open, the controller is in a de-energized state and cannot send a closing control signal to the trip unit. Therefore, the trip unit can only be closed manually. However, after the trip unit is closed, the controller is powered on and can send a disconnect control command to the trip unit, causing the trip unit to open and the controller to de-energize accordingly. Of course, the trip unit can also be disconnected manually.

[0043] For specific connection details, please refer to... Figure 1 The trip unit is located on the positive output side of the battery module. It includes a high-voltage input port and a high-voltage output port. The high-voltage input port is connected to the positive output terminal of the battery module, and the high-voltage output port is connected to the positive input port of the DC-DC converter. The trip unit also includes a single-pole single-throw switch located between the high-voltage input and high-voltage output ports to control the opening and closing of this connection. Furthermore, the trip unit includes a low-voltage input port and a low-voltage output port, both connected to a controller. The controller can control the opening and closing of the single-pole single-throw switch on the trip unit through these ports. Alternatively, the single-pole single-throw switch can also be opened or closed manually.

[0044] By employing the above method, the controller utilizes low-voltage power supply control, connecting the controller's low-voltage power supply and wake-up source together. The controller is connected to a DC-DC converter unit. When the trip unit switches from the open to the closed state, both the controller's low-voltage power supply and the low-voltage wake-up source simultaneously conduct, thus activating the controller and enabling normal monitoring and control. The trip unit draws power from the entire energy storage system, avoiding the imbalance that can occur when power is drawn from only one battery module.

[0045] For example, refer to Figure 1 The energy storage system may also include an inverter, which is connected between the battery module and the external power grid. The inverter converts the current input from the grid into current capable of charging the energy storage system, and also converts the current output from the energy storage system into current capable of being connected to the grid. The inverter enables the energy storage system to output 220V power, and also allows the system to be charged and stored using 220V power via the inverter.

[0046] In some embodiments, reference Figure 1The battery management system may further include a pre-charge resistor and a pre-charge contactor connected in series. The pre-charge resistor is connected to a trip unit, and the pre-charge contactor is connected to the inverter. The controller is also connected to the pre-charge contactor and is used to control the pre-charge contactor to close or open according to control parameters. That is, both the pre-charge resistor and the pre-charge contactor are connected to the battery module via a trip unit, so that when the trip unit is open, neither the pre-charge resistor nor the pre-charge contactor is energized. The controller can also send control commands to the pre-charge contactor to open or close it. For example, the controller is further used to: control the pre-charge contactor to close when the overall voltage in the overall parameters is less than a preset threshold, and control the pre-charge contactor to open when the overall voltage in the overall parameters is not less than the preset threshold. That is, when the overall voltage in the overall parameters is less than the preset threshold, the controller controls the pre-charge contactor to close; when the overall voltage in the overall parameters is not less than the preset threshold, the controller controls the pre-charge contactor to open.

[0047] For specific connections, for example, such as Figure 1 As shown, both the pre-charge resistor and the pre-charge contactor are connected to the positive output terminal of the battery module. One end of the pre-charge resistor is connected to the high-voltage output port of the trip unit, and the other end is connected to the high-voltage input port of the pre-charge contactor. The high-voltage output port of the pre-charge contactor is connected to the inverter. The single-pole single-throw switch on the pre-charge contactor can open or close the high-voltage input port and the high-voltage output port of the pre-charge contactor. The controller is connected to the low-voltage input port and the low-voltage output port of the pre-charge contactor to control the opening or closing of the single-pole single-throw switch on the pre-charge contactor.

[0048] For example, refer to Figure 1 The battery management system may also include a main positive contactor and a main negative contactor. The trip unit is connected to the positive output terminal of the battery module. The main positive contactor is connected between the trip unit and the inverter, and is connected in parallel with both the pre-charge resistor and the pre-charge contactor. The main negative contactor is connected to the negative output terminal of the battery module, and the inverter is also connected to the negative output terminal of the battery module via the main negative contactor. The controller is connected to both the main positive and main negative contactors and is used to control the closing or opening of the main positive and main negative contactors according to control parameters. For example, the controller may first control the pre-charge contactor and the main negative contactor to close, and then control the main positive contactor to close only when the overall voltage in the overall parameters is not less than a preset threshold.

[0049] For specific connections, for example, such as Figure 1As shown, the main positive contactor acts as a control switch connecting the positive output terminal of the battery module and the positive input terminal of the inverter. The controller can control the opening and closing of the main positive contactor, thereby connecting the positive output terminal of the battery module and the positive input terminal of the inverter. Similarly, the main negative contactor acts as a control switch connecting the negative output terminal of the battery module and the negative input terminal of the inverter. The controller can control the opening and closing of the main negative contactor, thereby connecting the negative output terminal of the battery module and the negative output terminal of the inverter. When both the main positive and negative contactors are closed, a circuit is formed between the battery module and the inverter, enabling charging or discharging.

[0050] like Figure 1 As shown, a trip unit is connected between the main positive contactor and the positive output terminal of the battery module, so that even when the trip unit is open, the power circuit between the battery module and the inverter can still be controlled to disconnect. Furthermore, the main positive inverter is connected in parallel with a pre-charge resistor and a pre-charge contactor. Therefore, after the trip unit is opened, the controller first closes the main negative contactor, causing the main positive contactor to open, then closes the pre-charge contactor for a period of time until the voltage at the input terminal of the main positive contactor reaches a preset threshold, before closing the main positive contactor and opening the pre-charge contactor, thus enabling high-voltage discharge.

[0051] In specific connection scenarios, such as Figure 1 As shown, the high-voltage input port of the main positive contactor is connected to the high-voltage output port of the trip unit, and the high-voltage output port of the main positive contactor is connected to the positive input port of the inverter. Both the low-voltage input and output ports of the main positive contactor are connected to the controller to receive control commands and control the opening or closing of the single-pole single-throw switch on the main positive contactor. The high-voltage input port of the main negative contactor is connected to the negative output terminal of the battery module, and the high-voltage output port of the main negative contactor is connected to the negative input port of the inverter. Both the low-voltage input and output ports of the main negative contactor are connected to the controller to receive control commands and control the opening or closing of the single-pole single-throw switch on the main negative contactor.

[0052] By configuring the aforementioned trip unit, pre-charge contactor, main positive contactor, and main negative contactor on the battery management system, the controller manages the control functions of the main positive, main negative, pre-charge, and trip units respectively. The control logic of the trip unit differs from the other three (pre-charge contactor, main positive contactor, and main negative contactor). Under normal conditions, the trip unit should not disconnect. It only disconnects when the battery management system detects a serious fault in the entire energy storage system and necessitates disconnecting the high voltage. The trip unit can be disconnected by controlling a PWM wave. Since the trip unit itself requires a large current to drive, a short-term high-level drive from a different location can cause the entire trip unit to completely disconnect, thus completely eliminating the voltage supply and wake-up source for the battery management system, thereby putting the battery management system into a completely powered-off state.

[0053] In this application, when the battery management system (BMS) is powered on, it is woken up and its control functions are executed by manually closing the trip unit. Unlike vehicle applications, in this application, after the BMS is woken up, it can immediately perform high-voltage pre-charge control via the aforementioned pre-charge resistor and pre-charge contactor, thus enabling immediate pre-charge control and high-voltage discharge. Once CAN communication with the inverter is established within a preset time period (e.g., 60 seconds), the BMS can operate normally. Otherwise, if no message is received from the inverter, the BMS can perform a high-voltage power-off operation.

[0054] In some embodiments, reference Figure 1 Furthermore, a main fuse can be installed between the trip unit and the battery module. This main fuse is a single fuse that melts when the voltage exceeds a certain threshold, thus protecting the circuit. For example... Figure 1 As shown, the fuse detection interface on the controller can also be connected to a wire node between the main fuse and the trip unit to detect whether the main fuse has blown.

[0055] In some other embodiments, such as Figure 1 As shown, an output voltage positive sampling point can also be set at a wire node between the main positive contactor and the precharge contactor and the inverter. The output voltage positive sampling interface on the controller is connected to the output voltage positive sampling point to detect the magnitude of the output voltage in the positive section. Of course, as... Figure 1 As shown, an output voltage negative sampling point can also be set at a wire node between the main negative contactor and the inverter. The output voltage negative sampling interface on the controller is connected to the output voltage negative sampling point to detect the magnitude of the output voltage of the negative part.

[0056] For example, such as Figure 1As shown, a shunt meter can also be installed on the controller. The shunt meter connects between the DC-DC converter and the controller, and the DC-DC converter supplies power to the controller through the shunt meter. The shunt meter is also connected between the negative terminal of the battery module and the main negative contactor to detect the current output of the DC-DC converter. Thus, the shunt meter can be used to determine the direction and magnitude of the current flow. This shunt meter, as a current detection unit, can effectively achieve current detection. The charging current can be defined as positive and the discharging current as negative in the shunt meter. For specific connections, refer to the example provided. Figure 1 One end of the shunt meter is connected to the negative output terminal of the battery module, and the other end of the shunt meter is connected to both the main negative contactor and the DC-DC converter, so as to detect the overall current status of the battery module.

[0057] In some embodiments, reference Figure 1 The battery management system may also include a communication module. This communication module is connected to both the controller and the inverter, allowing both the communication module and the inverter to supply power. This ensures that even when the trip unit is disconnected, external power can still be supplied to the communication module via the inverter, guaranteeing its normal operation. The communication module transmits one or more of the following parameters to the outside world: individual cell parameters, overall parameters, and control parameters. Specifically, the communication module can transmit only one of these parameters, or any two, or all of them. For example, the communication module also receives control commands from the outside world and transmits them to the controller, facilitating the input of control commands from the outside world to the energy storage system.

[0058] When configuring this communication module, various modules can be used, including but not limited to WiFi, Bluetooth, and UWB modules. The battery management system (BMS) enables CAN (a type of local area network) communication with the entire power station via this module. The main nodes on the CAN network can include inverters and the communication module. The communication module can upload all signals from the BMS to the cloud platform, facilitating data exchange between the energy storage system and maintenance personnel or users' mobile apps.

[0059] In a preferred embodiment, a wireless upgrade module can be added to the communication module. The wireless upgrade module can perform remote data reading and program upgrades, and can also remotely control the battery management system, thus controlling power supply and consumption.

[0060] In some embodiments, such as Figure 1As shown, the battery management system can also include a display screen, which can be connected to both the controller and the inverter. This allows the display screen to still be powered by the inverter even when the trip unit is disconnected, ensuring its normal operation.

[0061] For example, the individual parameters mentioned above may include the capacity, voltage, current, state of charge, or temperature of each battery module. Of course, they may also include other types of information that the battery information collector can collect from the battery modules. Correspondingly, the overall parameters may include the overall capacity, overall voltage, overall current, overall state of charge, or overall temperature of the energy storage system. Of course, the overall parameters may also be other parameters of the overall type of the energy storage system obtained by calculating based on the information collected by the battery information collector.

[0062] For example, individual parameters may include the voltage parameters of each battery module. In this case, the overall parameters may include the expected total voltage parameters of the energy storage system calculated based on the voltage parameters collected by each battery information collector. The controller can also be used to detect the actual total voltage parameters of the energy storage system and compare the expected total voltage parameters with the actual total voltage parameters to determine if any battery modules have malfunctioned. Specifically, if the expected total voltage parameters and the actual total voltage parameters are close to or essentially identical, the battery modules are considered normal, and there is no communication failure in the battery information collectors of the battery modules. If the expected total voltage parameters differ significantly from the actual total voltage parameters, the controller indicates a battery module malfunction, requiring repair.

[0063] In addition, if the total voltage parameters are matched successfully and the number of battery modules is matched successfully, the controller can recalculate the total capacity information of the energy storage system and recalculate the power consumption.

[0064] In some embodiments, when controlling the main positive contactor, the main negative contactor, and the trip unit, the controller is further configured to: determine whether a first fault type has occurred in the energy storage system based on overall parameters; and if the first fault type has occurred, the controller may also control both the main positive contactor and the main negative contactor to disconnect. This first fault type can be a minor fault that does not interrupt the power supply from the battery module to the controller, and subsequent manual restart is not required.

[0065] In a preferred embodiment, the controller is further configured to: determine whether a second fault type has occurred in the energy storage system based on overall parameters, and when the energy storage system experiences a second fault type, the controller can also control the trip unit to disconnect. This second fault type can be a relatively serious major fault that interrupts the power supply from the battery module to the controller, requiring subsequent manual restart.

[0066] In other words, by distinguishing between the first and second fault types, a two-stage energy control system is implemented using a trip unit, a main positive contactor, and a main negative contactor. When a minor first fault type occurs, the impact of the fault can be reduced by disconnecting the main positive and main negative contactors. When a more significant second fault type occurs, the controller activates the trip unit to completely disconnect the battery module from all circuits.

[0067] For example, the first fault type mentioned above is a less serious fault type. If the first fault type is encountered and a high-voltage power outage is necessary, the controller will disconnect the main positive contactor and the main negative contactor according to the current situation.

[0068] The second type of fault can be a severe low state of charge (SOC). Because the battery management system continuously consumes energy from the battery modules and DC-DC converter after waking up, this results in continuous energy consumption of the battery modules in the energy storage system. Therefore, when the SOC falls below a threshold (e.g., 5%), the control logic to activate the trip unit can be triggered.

[0069] When defining the aforementioned energy storage system, it can be a residential energy storage system. The energy storage system described above, when applied to residential energy storage scenarios, can achieve a minimal design and use, effectively realizing energy storage and discharge within the residential energy storage system. Of course, the energy storage system can also be other energy storage systems with a variable number of connected battery modules, such as power plant energy storage systems or commercial energy storage systems.

[0070] Under current technology, any increase or decrease in the number of battery modules, i.e., a change in the energy storage system capacity, involves matching information such as the number of battery module strings and capacity. This application improves the controller strategy of the battery management system to automatically match parameters such as battery capacity and the number of battery module strings. This application enables energy storage systems containing at least two battery modules to share a single battery management system, which includes a controller. Each battery module's battery information acquisition unit is connected to the controller, allowing the controller to receive individual parameters collected by each battery information acquisition unit for each battery module. The controller then calculates the overall parameters of the energy storage system based on these individual parameters and adjusts the control parameters of the battery management system accordingly. This integrates the individual parameter information of different battery modules to obtain the overall parameters of the energy storage system. The control parameters of the battery management system are then adaptively adjusted based on these overall parameters, simplifying the complex control logic and facilitating accurate control of the entire energy storage system's state. For example, after adding a battery module, the number of battery modules in the energy storage system, the number of cells in each battery module, and the voltage value of each individual battery module can be read back. The battery information acquisition unit then transmits these individual cell parameters to the controller. The controller calculates the overall parameter information based on the individual cell information received from the acquisition unit. The controller then adaptively adjusts the control parameters in the battery management system based on this overall parameter information, achieving adaptive parameter adjustment and demonstrating good automatic algorithm functionality.

[0071] In the various embodiments shown above, by setting an interface component to connect at least two battery modules in a switchable manner, the number of battery modules connected to the energy storage system can be varied. Once any battery module is connected to the energy storage system, it actively transmits its individual parameters. All battery modules connected to the energy storage system share a battery management system, which includes a controller. Each battery information collector is connected to the controller, enabling the controller to receive individual parameters collected by each battery information collector for each battery module. The controller can then calculate the overall parameters of the energy storage system based on the received individual parameters, determine whether the number of battery modules connected to the energy storage system has changed based on the overall parameters, and adjust the control parameters of the battery management system according to the overall parameters when the number of battery modules connected to the energy storage system changes. Compared to existing home energy storage systems, this application can calculate the overall parameters based on individual parameters, determine whether the number of battery modules connected to the energy storage system has changed based on the overall parameters, and adjust the control parameters of the battery management system according to the overall parameters when the number of battery modules changes. This allows the overall parameters of the energy storage system to be obtained by integrating the individual parameter information of different battery modules, and the control parameters of the battery management system to be adaptively adjusted based on the overall parameters, simplifying the complex control logic and facilitating accurate control of the entire energy storage system by the battery management system.

[0072] In addition, this application embodiment also provides a power station, which includes any of the above-mentioned energy storage systems. The power station may also include a power generation device. Specifically, the power generation device may be a photovoltaic power generation device, a hydropower generation device, a coal-fired power generation device, or a nuclear power generation device, etc. The power generation device is connected to the energy storage system; specifically, the power generation device is connected to the inverter in the energy storage system to charge the energy storage system. The power station may also include a power grid, which may also be connected to the inverter in the energy storage system to charge the energy storage system or to enable the energy storage system to discharge to the outside.

[0073] The present invention has been described through the above embodiments. However, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit the invention to the scope of the described embodiments. Furthermore, those skilled in the art will understand that the present invention is not limited to the above embodiments, and many more variations and modifications can be made based on the teachings of the present invention, all of which fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An energy storage system, characterized in that, include: At least two battery modules, each of which is equipped with a battery information collector, which is used to collect the individual parameters of the battery module itself; An interface component is provided for enabling on / off connection of at least two battery modules, thereby allowing the number of battery modules connected to the energy storage system to be variable; once any battery module is connected to the energy storage system, it actively transmits its own individual parameters. A battery management system includes a controller connected to the interface component; The controller is configured to: receive parameters for each individual cell, calculate the overall parameters of the energy storage system based on the individual cell parameters, determine whether the number of battery modules has changed based on the overall parameters, and adjust the control parameters of the battery management system based on the overall parameters when the number of battery modules changes; Each of the interface components includes a first interface and a second interface; both the first interface and the second interface are connected to the controller. The first interface is used to connect to the battery in the battery module, and the second interface is used to connect to the battery information collector in the battery module. The battery information collector transmits the collected individual cell parameters to the controller via the second interface. At least two of the battery information collectors are connected in series via the corresponding second interface; The controller includes a first control interface and a second control interface; one end of the battery information collector connected in series is connected to the first control interface, and the other end is connected to the second control interface; the battery information collectors communicate with each other using a double-loop daisy-chain communication method.

2. The energy storage system as described in claim 1, characterized in that, The battery management system also includes a DC-DC converter; The DC-DC converter is used to convert the DC power output by the energy storage system from a first voltage to a second voltage, and then power the controller; wherein the first voltage is greater than the second voltage.

3. The energy storage system as described in claim 2, characterized in that, The battery management system also includes a trip unit connected between the battery module and the DC-DC converter; When the trip unit is closed, the battery module supplies power to the controller through the DC-DC converter; Furthermore, the controller is also connected to the trip unit, and the controller is also used to control the trip unit to switch from a closed state to an open state according to the control parameters.

4. The energy storage system as described in claim 3, characterized in that, It also includes inverters; The battery management system further includes: a pre-charge resistor and a pre-charge contactor connected in series; wherein the pre-charge resistor is connected to the trip unit, and the pre-charge contactor is connected to the inverter; Furthermore, the controller is also connected to the precharge contactor, and the controller is further configured to: control the precharge contactor to close when the overall voltage in the overall parameters is less than a preset threshold, and control the precharge contactor to open when the overall voltage in the overall parameters is not less than the preset threshold.

5. The energy storage system as described in claim 4, characterized in that, The battery management system also includes a main positive contactor and a main negative contactor; The trip unit is connected to the positive output terminal of the battery module, the main positive contactor is connected between the trip unit and the inverter, and the main positive contactor is connected in parallel with the pre-charge resistor and the pre-charge contactor. The main negative contactor is connected to the negative output terminal of the battery module, and the inverter is also connected to the negative output terminal of the battery module through the main negative contactor. The controller is connected to both the main positive contactor and the main negative contactor. The controller is also used to: control the pre-charge contactor and the main negative contactor to close, and control the main positive contactor to close when the overall voltage in the overall parameters is not less than the preset threshold.

6. The energy storage system as described in claim 5, characterized in that, The controller is also configured to: determine whether the energy storage system has experienced a first fault type based on the overall parameters, and when the energy storage system experiences the first fault type, control both the main positive contactor and the main negative contactor to disconnect.

7. The energy storage system as described in claim 6, characterized in that, The controller is also configured to: determine whether the energy storage system has experienced a second fault type based on the overall parameters, and control the trip unit to disconnect when the energy storage system experiences the second fault type.

8. The energy storage system as described in claim 5, characterized in that, The controller is equipped with a shunt meter, which is connected between the DC-DC converter and the controller. The shunt meter is also connected between the negative terminal of the battery module and the main negative contactor to detect the current information output by the DC-DC converter.

9. The energy storage system as described in claim 4, characterized in that, The battery management system also includes a communication module, which is communicatively connected to both the controller and the inverter. The communication module is used to transmit one or more of the individual parameters, the overall parameters, and the control parameters to the outside world, and is also used to receive control commands from the outside world and transmit the control commands to the controller.

10. The energy storage system as described in any one of claims 1 to 9, characterized in that, The individual parameters include the capacity, voltage, current, state of charge, or temperature of each battery module, while the overall parameters include the overall capacity, overall voltage, overall current, overall state of charge, or overall temperature of the energy storage system.

11. The energy storage system as described in any one of claims 1 to 9, characterized in that, The individual parameters include the voltage parameters of each battery module, and the overall parameters include the expected total voltage parameters of the energy storage system calculated based on the voltage parameters collected by each battery information collector. The controller is also used to detect the actual total voltage parameter of the energy storage system and compare the expected total voltage parameter with the actual total voltage parameter to determine whether the battery module has malfunctioned.

12. A power station, characterized in that, Including the energy storage system as described in any one of claims 1 to 11.

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