Battery system and its operation method

Abstract

A battery system according to one embodiment of the present invention may include a plurality of batteries; and a battery control device that controls main switches located on the input / output paths of each of the plurality of batteries to control the batteries so that they are connected in parallel to a DC link. Here, the battery control device can select a target battery to be connected in parallel based on the state information of the batteries, control the target battery to be connected in parallel, and sequentially control the main switch of each of the target batteries so that the target batteries are connected to the DC link at different times.

Description

Technical Field

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2024-0038196, filed with the Korean Intellectual Property Office on March 20, 2024, and all of the content disclosed in the document of the Korean patent application is incorporated herein.

[0002] The present invention relates to a battery system and an operating method thereof, and more particularly, to a battery system including a battery control device for controlling each main switch of a battery and an operating method thereof.

Background Art

[0003] A secondary battery is a battery that can be reused through charging even after discharge, and can be used as an energy source for small devices such as mobile phones, tablet PCs, and vacuum cleaners, and can also be used as an energy source for medium and large devices such as automobiles and energy storage systems (ESSs) for smart grids.

[0004] A secondary battery is applied to a system in the form of an assembly such as a battery pack in which a plurality of battery cells are electrically connected according to the requirements of the system, or a battery rack to which battery packs are electrically connected. In the case of an ESS for a smart grid, a high-capacity battery system in which a plurality of battery racks are connected in parallel can be applied to satisfy the required capacity of the system.

[0005] When a voltage difference occurs between battery racks during the operation of a battery system, rack balancing control is performed to minimize such a voltage difference. Here, in the case of a battery system including a plurality of racks connected in parallel, racks that satisfy a predefined voltage imbalance condition are connected in parallel with each other, and active balancing of the connected racks is performed, so that the voltage imbalance between the racks can be eliminated.

[0006] Generally, a higher-level control unit (e.g., a Bank Battery Management System) can control the balancing of racks by switching each main switch (e.g., a positive main contactor) of the racks to be balanced to a closed state, so that the racks are simultaneously connected to the DC link. In this case, a power supply (e.g., a Switching Mode Power Supply) that supplies power to each main switch of the racks may have insufficient capacity, causing any Rack Battery Management System (RBMS) to reset and potentially resulting in a communication error between the higher-level control unit and the corresponding RBMS.

[0007] Prior art related to the present invention is KR 10-2015-0025215. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] To address one or more of the above-mentioned problems, embodiments of the present disclosure also provide a battery system that prevents communication errors that may occur during battery balancing.

[0009] To address one or more of the above-mentioned problems, the embodiments of the disclosure also provide a method for operating such a battery system.

[0010] To address one or more of the above-mentioned problems, embodiments of the present disclosure also provide a battery control device located within such a battery system. [Means for solving the problem]

[0011] To achieve the above-mentioned objectives of this disclosure, a battery system according to one embodiment of this disclosure may include a plurality of batteries; and a battery control device further configured to control a main switch located on the input / output path of each of the plurality of batteries so that the batteries are connected in parallel to a DC link.

[0012] Here, the battery control device may be further configured to select target batteries to be connected in parallel based on the state information of the batteries, control the target batteries so that they are connected in parallel, and sequentially control the main switches of each target battery so that the target batteries are connected to the DC link at different times.

[0013] The above-described battery control device may be further configured to determine a battery that satisfies a predefined imbalance condition based on one or more of the voltage value or the SOC (State of Charge) value as the target battery.

[0014] The battery control device described above may be further configured to determine a priority for controlling the target battery based on one of the battery identifier, state value, and location.

[0015] The above-described battery control device may be further configured to switch the positive electrode main switch of the second target battery to the closed state after switching the positive electrode main switch of the first target battery to the closed state.

[0016] The above battery system may further include a precharge circuit connected in parallel to the positive terminal main switch of each of the plurality of batteries, and including a precharge resistor and a precharge switch for each. Here, the battery control device may be further configured to switch the positive terminal main switch of the first target battery to the closed state after switching the precharge switch of the first target battery to the closed state. Subsequently, the battery control device may be further configured to switch the positive terminal main switch of the second target battery to the closed state after switching the precharge switch of the second target battery to the closed state.

[0017] The battery control device may be further configured to switch the positive electrode main switch of the first target battery to the closed state, then switch the precharge switch of the first target battery to the open state, and at the time the precharge switch of the first target battery is switched to the open state, switch the precharge switch of the second target battery to the closed state.

[0018] The battery control device may be further configured to switch the precharge switch and negative electrode main switch of the first target battery to the closed state, and then switch the positive electrode main switch of the first target battery to the closed state. Subsequently, the battery control device may be further configured to switch the precharge switch and negative electrode main switch of the second target battery to the closed state, and then switch the positive electrode main switch of the second target battery to the closed state.

[0019] The battery control device can, after switching the positive terminal main switch of the first target battery to the closed state, switch the precharge switch of the first target battery to the open state, and at the moment the precharge switch of the first target battery is switched to the open state, switch the precharge switch and the negative terminal main switch of the second target battery to the closed state.

[0020] The above-mentioned battery may be any one of the following: a battery module, a battery pack, a battery rack, or a battery bank.

[0021] A method for operating a battery system according to one embodiment of the present invention for achieving the above-mentioned other objective is a method for operating a battery system by a battery control device located in a battery system including a plurality of batteries that can be connected in parallel on a DC link, the method comprising: selecting a target battery to be connected in parallel based on the state information of the batteries; and sequentially controlling main switches located on the input / output paths of each of the target batteries so that the target batteries are connected to the DC link at different times.

[0022] The step of selecting the target battery may include a step of determining, as the target battery, a battery that satisfies a pre-defined imbalance condition based on one or more of a voltage value or a SOC (State Of Charge) value.

[0023] The step of sequentially controlling the main switch may include a step of determining a priority for controlling the target battery based on one of an identifier, a state value, and a position of the battery.

[0024] The step of sequentially controlling the main switch may include a step of switching the positive main switch of the first target battery to the closed state; and, thereafter, a step of switching the positive main switch of the second target battery to the closed state.

[0025] The battery system may further include a pre-charge circuit, each of the pre-charge circuits being connected in parallel with the positive main switch of each of the plurality of batteries and including a respective pre-charge resistor and a pre-charge switch. Here, the step of sequentially controlling the main switch may include a step of switching the pre-charge switch of the first target battery to the closed state and then switching the positive main switch of the first target battery to the closed state; and, thereafter, a step of switching the pre-charge switch of the second target battery to the closed state and then switching the positive main switch of the second target battery to the closed state.

[0026] The step of sequentially controlling the main switch may include a step of switching the positive main switch of the first target battery to the closed state and then switching the pre-charge switch of the first target battery to the open state; and a step of switching the pre-charge switch of the second target battery to the closed state when the pre-charge switch of the first target battery is switched to the open state. <00​According to an embodiment of the present disclosure, a battery control device is located in a battery system including a plurality of batteries that can be connected in parallel on a DC link, and includes at least one processor; and a memory configured to store at least one instruction executed through the at least one processor.

[0028] Here, the at least one instruction may include an instruction to select a target battery to be connected in parallel based on the state information of the battery; and an instruction to sequentially control main switches arranged on respective input / output paths of the target battery so that the target battery is connected to the DC link at different times.

Advantages of the Invention

[0029] According to the embodiment of the present disclosure as described above, by controlling so that the balancing target batteries are connected to the DC link with a time difference, it is possible to prevent communication errors in the battery system that may occur when performing battery balancing.

Brief Description of the Drawings

[0030] [Figure 1] It is a block diagram of a general energy storage system. [Figure 2] It is a block diagram of a battery system according to an embodiment of the present invention. [Figure 3] It is a circuit diagram for explaining an input / output path of a battery according to an embodiment of the present invention. [Figure 4] It is an operation flowchart of an operation method of a battery system according to an embodiment of the present invention. [Figure 5] It is a reference diagram for explaining an operation method of a battery system according to an embodiment of the present invention. [Figure 6] It is a reference diagram for explaining an operation method of a battery system according to another embodiment of the present invention. [Figure 7] It is a reference diagram for explaining an operation method of a battery system according to still another embodiment of the present invention. <000This is a block diagram of a battery control device according to an embodiment of the present invention. [Modes for carrying out the invention]

[0031] The present invention can be modified in various ways and has many embodiments; therefore, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this should be understood not as limiting the present invention to specific embodiments, but rather as including all modifications, equivalents, or substitutes that fall within the spirit and technical scope of the present invention. Similar reference numerals are used for similar components in the description of each drawing.

[0032] Terms such as First, Second, A, B, etc., may be used to describe various components, but the components should not be limited by such terms. The terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the First component may be named the Second component, and similarly, the Second component may be named the First component. The term "and / or" includes a combination of multiple related items or one of multiple related items.

[0033] When it is stated that one component is "combined" or "connected" to another component, it should be understood that this may mean that it is directly linked to or connected to the other component, but that there may also be another component in between. Conversely, when it is stated that one component is "directly connected" or "directly linked" to another component, it should be understood that there is no other component in between.

[0034] The terms used in this application are used solely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless they are clearly different in context. In this application, terms such as “includes” or “having” are intended to specify the presence of features, figures, steps, actions, components, parts, or combinations thereof as described in the specification, and should not be understood to preemptively exclude the presence or possibility of adding one or more other features, figures, steps, actions, components, parts, or combinations thereof.

[0035] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those generally understood by a person of ordinary skill in the art to which this invention pertains. Terms as defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not as ideal or overly formal unless explicitly defined herein.

[0036] Some terms used in this specification are defined as follows:

[0037] A battery cell is a basic unit that stores electricity, while a battery module refers to an assembly of multiple battery cells that are electrically connected.

[0038] A battery rack refers to a single-structure system in which modules, as defined by the battery manufacturer, are connected in series or parallel, and can be monitored and controlled through a Battery Management System (BMS). A battery rack can consist of multiple battery modules and a battery protection unit or other protective device. Depending on the device or system in which the batteries are used, the battery modules may also be called battery packs.

[0039] A battery bank can refer to a group of large battery rack systems configured by connecting multiple racks in parallel. A bank BMS (BBMS) may monitor and control several rack BMSs (RBMS), each of which manages its own battery rack.

[0040] A battery assembly may include multiple electrically connected battery cells and means a collection that functions as a power source when applied to a particular system or device. Here, a battery assembly may also mean a battery module, battery pack, battery rack, or battery bank, and the scope of the present invention is not limited to these individuals.

[0041] A Battery System Controller (BSC) is a device that provides top-level control to a battery system, including battery systems at the bank level, and can also be used as a control device in a battery system with multiple bank-level structures.

[0042] SOC (State of Charge) represents the current charge state of a battery as a percentage [%], while SOH (State of Health) represents the current state of a battery compared to its ideal or initial state as a percentage [%].

[0043] Figure 1 is a block diagram of a typical energy storage system.

[0044] In an energy storage system (ESS), the basic unit of a battery for storing energy or electricity is the battery cell. Typically, a series or parallel combination of battery cells forms a battery module, and multiple battery modules can constitute a battery rack. That is, a battery rack, as a series or parallel combination of battery modules, can be the basic unit of a battery system. Here, depending on the device or system in which the battery is used, a battery module may also be called a battery pack.

[0045] Referring to Figure 1, a single battery rack 10 may include multiple battery modules and one battery protection unit (BPU) or other protection device. The battery rack can be monitored and controlled through an RBMS (Rack BMS). The RBMS can monitor the current, voltage, and temperature of each battery rack under its control, calculate the battery's SOC (Status of Charge) based on the monitoring results, and control charging and discharging.

[0046] On the other hand, a Battery Protection Unit (BPU) is a device for protecting batteries from abnormal and fault currents on a rack-by-rack basis. A BPU may include a main contactor (MC), fuse, circuit breaker (CB), or disconnect switch (DS). Here, the main contactor may include a positive and negative main contactor. The BPU can control the battery system on a rack-by-rack basis by switching the main contactor on / off according to the RBMS control. The BPU can also protect batteries from short-circuit currents using a fuse in the event of a short circuit. In this way, existing battery systems can be controlled through protection devices such as BPUs and switchgear.

[0047] On the other hand, each battery section, which includes multiple batteries and peripheral circuits and devices, may be provided with a Battery System Controller (BSC) 20, which can monitor and control parameters such as voltage, current, temperature, and circuit breakers. The Battery System Controller may also be the highest-level control device for a battery system, including a bank-unit battery system that includes multiple battery racks, and can also be used as a control device in a battery system with a multi-bank level structure.

[0048] Furthermore, a Power Conversion System (PCS) 40 provided for each battery section performs actual charging and discharging based on charge / discharge commands from the EMS 30. The Power Conversion System may consist of a power conversion unit (DC / AC inverter) and a controller. On the other hand, the output of each BPU can be connected to a power generation device (e.g., a solar power generation device) and the PCS 40 via a DC link (or DC bus), and the PCS 40 can be connected to the grid. In addition, an Energy Management System (EMS) 30 or Power Management System (PMS) manages the energy storage system as a whole.

[0049] Figure 2 is a block diagram of a battery system according to an embodiment of the present invention.

[0050] Referring to Figure 2, an embodiment of the present invention may include a plurality of batteries 100 and a battery control device 200 configured to manage and control the plurality of batteries.

[0051] In this invention, battery 100 may mean a battery rack, but the scope of the invention is not limited thereto. For example, battery 100 may be any one of a battery module, a battery pack, a battery rack, and a battery bank.

[0052] The batteries 100 can be connected in parallel to each other. Here, each battery 100 can be individually connected to a DC link and connected in parallel with another battery.

[0053] Each of the batteries 100 may include a main switch located on the input / output path. Here, the on / off control of the main switch can connect or disconnect the battery 100 to the DC link.

[0054] Each of the batteries 100 may further include a precharge circuit located on the input / output path. Here, the precharge circuit may include a precharge resistor and a precharge switch connected in series.

[0055] Each of the batteries 100 may include a battery management system (BMS) internally. Here, the battery control device 200 can be a higher-level control device connected to each of the battery management systems of the batteries 100, and can be, for example, a bank BMS (BBMS) connected to multiple RBMSs, a battery system controller (BSC), an energy management system (EMS), or a power management system (PMS).

[0056] The battery control device 200 can control the operation of each main switch of the battery 100. Furthermore, the battery control device 200 can control the operation of each pre-charge switch of the battery 100.

[0057] The battery control device 200 can collect status information of the battery 100. Here, the status information may include one or more of the following: the battery's voltage value, current value, state of charge (SOC) value, and temperature.

[0058] The battery control device 200 can select target batteries, which are connected in parallel. Here, the battery control device 200 can determine from among the batteries 100 that satisfy a predefined imbalance condition as the target battery.

[0059] The battery control device 200 can control the main switch and precharge switch of the target battery so that the target batteries are connected in parallel. Here, the battery control device 200 can transmit switch control signals to the BMS of the target battery to control the operation of the main switch and precharge switch of the target battery.

[0060] Figure 3 is a circuit diagram illustrating the input / output path of a battery according to an embodiment of the present invention.

[0061] Each of the batteries 100 may include multiple battery cells 110 and a main switch located on the input / output path.

[0062] The main switch of battery 100 may include a positive main switch 121 located on the positive terminal line. When the positive main switch 121 is switched from the off (open) state to the on (closed) state, it is electrically connected to the DC link, and battery 100 can be connected in parallel with other batteries. Conversely, when the positive main switch 121 is switched from the on (closed) state to the off (open) state, the electrical connection to the DC link is disconnected, and the parallel connection between battery 100 and other batteries can be released.

[0063] The main switch of battery 100 may further include a negative main switch 122 located on the negative terminal line. Here, when the positive main switch 121 and the negative main switch 122 are switched from the open state to the closed state, they are electrically connected to the DC link, allowing battery 100 to be connected in parallel with other batteries. Conversely, when either the positive main switch 121 or the negative main switch 122 is switched from the closed state to the open state, the electrical connection to the DC link is disconnected, and the parallel connection between battery 100 and other batteries is released.

[0064] Each of the batteries 100 may further include a precharge circuit located on the input / output path. Here, the precharge circuit may include a precharge resistor 124 and a precharge switch 123 connected in series with the positive main switch 121. Here, when the precharge switch 123 and the negative main switch 122 are switched from the open to the closed state, and then the positive main switch 121 is switched from the open to the closed state, the batteries 100 can be connected in parallel with other batteries. After that, the precharge switch 123 can be switched from the closed to the open state.

[0065] The battery control device 200 can determine a target battery from among multiple batteries 100 that satisfies predefined imbalance conditions, and control the target battery's positive electrode main switch 121, negative electrode main switch 122, and precharge switch 123 to ensure that the target batteries are connected in parallel. Here, the battery control device 200 can transmit switch control signals to each BMS of the target battery to control the on / off operation of the target battery's positive electrode main switch 121, negative electrode main switch 122, and precharge switch 123.

[0066] Figure 4 is an operation flowchart of the battery system operation method according to an embodiment of the present invention.

[0067] The operation method of the battery system according to an embodiment of the present invention can be performed by a battery control device located within the battery system. Here, the battery control device can correspond to a higher-level control device connected to each battery management device of the battery, and can correspond to, for example, a bank BMS (BBMS) connected to multiple RBMSs, a battery system controller (BSC), an energy management system (EMS), or a power management system (PMS).

[0068] The battery control device can select a target battery from among multiple batteries to be connected in parallel (or balanced) (S410). Here, the battery control device can determine a battery that satisfies a predefined imbalance condition as the target battery.

[0069] In the embodiment, the imbalance condition can be predefined based on one or more of the voltage value and the SOC value. For example, the imbalance condition can be defined as a battery that shows a difference of more than a threshold range from a predefined reference voltage value (or reference SOC value). On the other hand, the imbalance condition is a condition for selecting batteries to be balanced, and can be defined in various ways as needed.

[0070] The battery control device can connect the target batteries selected in S410 in parallel (S420) and perform active balancing on the target batteries (S430).

[0071] Here, the battery control device can sequentially control the main switches of each target battery with a time delay so that the target batteries are connected to the DC link at different times.

[0072] The battery control device can determine the priority order for sequential control of target batteries. Here, the battery control device can determine the control priority order based on one of the following: the battery identifier, the battery status value, and the battery location.

[0073] For example, a battery control device can check a predefined identification number for each target battery and assign sequential priorities, starting with the battery with the lowest identification number.

[0074] As another example, a battery control device can check the state value (e.g., voltage value or SOC value) for each target battery and assign a priority order starting with the battery whose difference from the reference state value is smallest.

[0075] Another example is that the battery control unit can check a predefined location identifier for each target battery and assign sequential priorities starting with the battery closest to the PCS.

[0076] The battery control device can sequentially control the main switch of each target battery according to the priority of the target batteries, so that the target batteries are connected to the DC link at different times. For example, the battery control device can switch the positive terminal main switch of the first target battery (the target battery with priority N) to the closed position, and then switch the positive terminal main switch of the second target battery (the target battery with priority N+1) to the closed position, so that the first and second target batteries are connected to the DC link with a time difference. This prevents communication errors within the battery system caused by insufficient capacity of the power supply device that supplies power to each switch of the batteries.

[0077] Figure 5 is a reference diagram illustrating the operation method of a battery system according to an embodiment of the present invention. Hereinafter, with reference to Figure 5, an embodiment of the operation method of a battery system in which a positive electrode main switch and a pre-charge circuit are provided on the battery's input / output path, but a negative electrode main switch is not provided, will be described.

[0078] The battery control unit can sequentially connect to the DC link in parallel according to the priority order of the target batteries selected for balancing.

[0079] Here, the battery control device can switch the precharge switch (SW_pc) of the first target battery (the Nth priority target battery) to the ON (closed) state, and then switch the positive electrode main switch (MSW_p) of the first target battery to the ON (closed) state.

[0080] Subsequently, the battery control device can switch the precharge switch (SW_pc) of the second target battery (the N+1 priority target battery) to the ON (closed) state, and then switch the positive terminal main switch (MSW_p) of the second target battery to the ON (closed) state.

[0081] For example, as shown in Figure 5, if batteries #1, #3, and #5 are selected as target batteries from among multiple batteries, and the control priority is determined to be in the order of batteries #1, #3, and #5, the battery control device can switch the precharge switch (SW_pc) of battery #1 to the ON (closed) state, then switch the positive terminal main switch (MSW_p) of battery #1 to the ON (closed) state, and then switch the precharge switch (SW_pc) of battery #1 to the OFF (open) state.

[0082] Subsequently, the battery control device sequentially controls the precharge switch (SW_pc) and positive terminal main switch (MSW_p) of batteries #3 and #5, respectively, as shown in Figure 5, so that batteries #1, #3, and #5 are connected to the DC link.

[0083] Assuming that the switching time for each switch is 1 second, batteries #1, #3, and #5 can be connected to the DC link 2 seconds, 5 seconds, and 8 seconds after the start of balancing control (when MSW_p is closed), respectively.

[0084] Figure 6 is a reference diagram illustrating an operation method of a battery system according to another embodiment of the present invention. Below, with reference to Figure 6, another embodiment of the operation method of the battery system described in Figure 5 will be described.

[0085] The battery control unit can be sequentially connected in parallel to the DC link according to the priority order of the target batteries selected for balancing.

[0086] Here, the battery control device can switch the precharge switch (SW_pc) of the first target battery (the Nth priority target battery) to the ON (closed) state, and then switch the positive electrode main switch (MSW_p) of the first target battery to the ON (closed) state. After that, the battery control device can switch the precharge switch (SW_pc) of the first target battery to the OFF (open) state.

[0087] Subsequently, the battery control unit can switch the precharge switch (SW_pc) of the second target battery (the N+1 priority target battery) to the ON (closed) state, and then switch the positive terminal main switch (MSW_p) of the second target battery to the ON (closed) state. After that, the battery control unit can switch the precharge switch (SW_pc) of the second target battery to the OFF (open) state.

[0088] Here, the battery control device can switch the precharge switch (SW_pc) of the second target battery to the ON (closed) state at the same time that the precharge switch (SW_pc) of the first target battery is switched to the OFF (open) state.

[0089] For example, as shown in Figure 6, if batteries #1, #3, and #5 are selected as target batteries from among multiple batteries, and the control priority is determined to be in the order of batteries #1, #3, and #5, the battery control device can switch the precharge switch (SW_pc) of battery #1 to the ON (closed) state, then switch the positive terminal main switch (MSW_p) of battery #1 to the ON (closed) state, and then switch the precharge switch (SW_pc) of battery #1 to the OFF (open) state.

[0090] Subsequently, the battery control device can sequentially control the precharge switch (SW_pc) and positive main switch (MSW_p) of battery #3 in the same manner as battery #1, so that batteries #1 and #3 are sequentially connected to the DC link. At this time, the battery control device can switch the precharge switch (SW_pc) of battery #3 to the on (closed) state when the precharge switch (SW_pc) of battery #1 is switched to the off (open) state.

[0091] Similarly, the battery control device sequentially controls the precharge switch (SW_pc) and positive terminal main switch (MSW_p) of battery #5 in the same way as batteries #1 and #3, and can switch the precharge switch (SW_pc) of battery #5 to the ON (closed) state when the precharge switch (SW_pc) of battery #3 is switched to the OFF (open) state.

[0092] Assuming that the switching time for each switch is 1 second, batteries #1, #3, and #5 can be connected to the DC link 2 seconds, 4 seconds, and 6 seconds after the start of balancing control (when MSW_p is closed), respectively.

[0093] If the switch included in the battery is a relay, then power supply from the power supply device is not required when switching the relay to the off (open) state. As a result, as shown in Figure 6, if simultaneous control of the first target battery and the second target battery is performed in the control section where the precharge switch (SW_pc) is switched to the off (open) state, the parallel connection time of the target batteries can be further shortened.

[0094] Figure 7 is a reference diagram illustrating an operation method of a battery system according to yet another embodiment of the present invention. Hereinafter, with reference to Figure 7, an embodiment of an operation method of a battery system in which a positive electrode main switch, a negative electrode main switch, and a pre-charge circuit are provided on the battery's input / output path will be described.

[0095] The battery control unit can be sequentially connected in parallel to the DC link according to the priority order of the target batteries selected for balancing.

[0096] Here, the battery control device can switch the precharge switch (SW_pc) and the negative electrode main switch (MSW_n) of the first target battery (the Nth priority target battery) to the ON (closed) state, and then switch the positive electrode main switch (MSW_p) of the first target battery to the ON (closed) state. After that, the battery control device can switch the precharge switch (SW_pc) of the first target battery to the OFF (open) state.

[0097] Subsequently, the battery control device can switch the precharge switch (SW_pc) and negative electrode main switch (MSW_n) of the second target battery (N+1 priority target battery) to the ON (closed) state, and then switch the positive electrode main switch (MSW_p) of the second target battery to the ON (closed) state. After that, the battery control device can switch the precharge switch (SW_pc) of the second target battery to the OFF (open) state.

[0098] Here, the battery control device can switch the precharge switch (SW_pc) and the negative terminal main switch (MSW_n) of the second target battery to the ON (closed) state when the precharge switch (SW_pc) of the first target battery is switched to the OFF (open) state.

[0099] For example, as shown in Figure 7, if batteries #1, #3, and #5 are selected as target batteries from among multiple batteries, and the control priority is determined to be in the order of batteries #1, #3, and #5, the battery control device can switch the precharge switch (SW_pc) and negative terminal main switch (MSW_n) of battery #1 to the ON (closed) state, then switch the positive terminal main switch (MSW_p) of battery #1 to the ON (closed) state, and then switch the precharge switch (SW_pc) of battery #1 to the OFF (open) state.

[0100] Subsequently, the battery control device can sequentially control the precharge switch (SW_pc), positive terminal main switch (MSW_p), and negative terminal main switch (MSW_n) of battery #3 in the same manner as battery #1, so that batteries #1 and #3 are sequentially connected to the DC link. At this time, when the precharge switch (SW_pc) of battery #1 is switched to the off (open) state, the battery control device can switch the precharge switch (SW_pc) and negative terminal main switch (MSW_n) of battery #3 to the on (closed) state.

[0101] Similarly, the battery control device sequentially controls the precharge switch (SW_pc), positive terminal main switch (MSW_p), and negative terminal main switch (MSW_n) of battery #5 in the same manner as batteries #1 and #3. When the precharge switch (SW_pc) of battery #3 is switched to the off (open) state, the precharge switch (SW_pc) and negative terminal main switch (MSW_n) of battery #5 can be switched to the on (closed) state.

[0102] Figure 8 is a block diagram of a battery control device according to an embodiment of the present invention.

[0103] The battery control device 800 according to an embodiment of the present invention is located in a battery system including a plurality of batteries that can be connected in parallel on a DC link, and can be linked with each battery management device of the batteries. For example, if the battery corresponds to a rack, the battery control device 800 can correspond to a BBMS, BSC, EMS, or PMS that is linked with a plurality of RBMSs.

[0104] The battery control device 800 may include at least one processor 810, a memory 820 for storing at least one instruction executed through the processor, and a transceiver 830 connected to a network for communication.

[0105] The above at least one instruction may include an instruction to select a target battery to be connected in parallel based on the state information of the battery; and an instruction to sequentially control the main switches located on each input / output path of the target battery so that the target battery is connected to the DC link at different times.

[0106] The instruction for selecting the target battery may include an instruction for determining a battery as the target battery if it satisfies a predefined imbalance condition based on one or more of the voltage value or the SOC (State of Charge) value.

[0107] The commands that sequentially control the main switches may include commands that determine the priority for controlling the target battery based on one of the battery identifier, state value, and position.

[0108] The commands for sequentially controlling the above main switches may include a command to switch the positive terminal main switch of the first target battery to the closed state, and a command to subsequently switch the positive terminal main switch of the second target battery to the closed state.

[0109] The above battery system may further include pre-charge circuits. Each of the pre-charge circuits may further include a pre-charge resistor and a pre-charge switch, connected in parallel to the positive terminal main switch of each of the plurality of batteries. Here, the commands for sequentially controlling the main switches may include a command to switch the pre-charge switch of a first target battery to the closed state, and then to switch the positive terminal main switch of the first target battery to the closed state; and then a command to switch the pre-charge switch of a second target battery to the closed state, and then to switch the positive terminal main switch of the second target battery to the closed state.

[0110] The commands for sequentially controlling the above main switches may include a command to switch the positive terminal main switch of the first target battery to the closed state, and then to switch the precharge switch of the first target battery to the open state; and a command to switch the precharge switch of the second target battery to the closed state at the time the precharge switch of the first target battery is switched to the open state.

[0111] The battery control device 800 may further include an input interface device 840, an output interface device 850, a storage device 860, and the like. Each component included in the battery control device 800 can communicate with one another via a bus 870.

[0112] Here, processor 810 can mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the method according to the embodiment of the present invention is performed. Memory (or storage device) can consist of at least one of volatile storage media and non-volatile storage media. For example, memory can consist of at least one of read-only memory (ROM) and random access memory (RAM).

[0113] The operation of the method according to an embodiment of the present invention can be embodied as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes all types of recording devices that store data that can be read by a computer system. Furthermore, computer-readable recording media can be distributed across networked computer systems, allowing computer-readable programs or code to be stored and executed in a distributed manner.

[0114] Some aspects of the present invention have been described in the context of apparatus, but they can also be described by corresponding methods, where a block or apparatus corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method can be described by corresponding blocks or items or features of corresponding apparatus. Some or all of the method steps can be carried out by (or using) hardware devices such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most important method steps can be carried out by such devices.

[0115] While preferred embodiments of the present invention have been described above with reference to the present invention, those skilled in the art will understand that the present invention can be modified and altered in various ways without departing from the spirit and scope of the invention as set forth in the following claims. [Explanation of Symbols]

[0116] 100:Battery 200: Battery control device

Claims

1. Multiple batteries; and The battery control device is configured to control a main switch located on the input / output path of each of the plurality of batteries so that the batteries are connected in parallel to a DC link. The aforementioned battery control device is A battery system further configured to select target batteries to be connected in parallel based on the state information of the aforementioned batteries, control the target batteries so that they are connected in parallel, and sequentially control the main switches of each of the target batteries so that the target batteries are connected to the DC link at different times.

2. The aforementioned battery control device is The battery system according to claim 1, further configured to determine a target battery that satisfies a predefined imbalance condition based on one or more of a voltage value or a State of Charge (SOC) value.

3. The aforementioned battery control device is The battery system according to claim 1, further configured to determine a priority for controlling the target battery based on one of the battery identifier, state value, and location.

4. The aforementioned battery control device is The battery system according to claim 1, further configured to switch the positive electrode main switch of a second target battery to the closed state after switching the positive electrode main switch of a first target battery to the closed state.

5. The aforementioned plurality of batteries each have a positive terminal main switch connected in parallel to a precharge circuit, which further includes a precharge resistor and a precharge switch, respectively. The aforementioned battery control device is After switching the precharge switch of the first target battery to the closed position, the positive terminal main switch of the first target battery is switched to the closed position. The battery system according to claim 1, further configured to subsequently switch the precharge switch of the second target battery to the closed state, and then switch the positive electrode main switch of the second target battery to the closed state.

6. The aforementioned battery control device is After switching the positive terminal main switch of the first target battery to the closed state, the precharge switch of the first target battery is switched to the open state. The battery system according to claim 5, further configured to switch the precharge switch of the second target battery to the closed state when the precharge switch of the first target battery is switched to the open state.

7. The aforementioned battery control device is After switching the precharge switch and negative terminal main switch of the first target battery to the closed state, the positive terminal main switch of the first target battery is switched to the closed state. The battery system according to claim 5, further configured to subsequently switch the precharge switch and negative electrode main switch of the second target battery to the closed state, and then switch the positive electrode main switch of the second target battery to the closed state.

8. The aforementioned battery control device is After switching the positive terminal main switch of the first target battery to the closed state, the precharge switch of the first target battery is switched to the open state. The battery system according to claim 7, further configured to switch the precharge switch and the negative terminal main switch of the second target battery to the closed state when the precharge switch of the first target battery is switched to the open state.

9. The aforementioned battery is The battery system according to claim 1, wherein the battery is one of a battery module, a battery pack, a battery rack, and a battery bank.

10. A method for operating a battery system, comprising a battery control device located within a battery system including multiple batteries that can be connected in parallel on a DC link, A step of selecting a target battery to be connected in parallel based on the battery status information; and A method for operating a battery system, comprising the step of sequentially controlling main switches located on each input / output path of the target battery so that the target battery is connected to the DC link at different times.

11. The step of selecting the target battery is: A method for operating a battery system according to claim 10, comprising the step of determining a target battery that satisfies a predefined imbalance condition based on one or more of a voltage value or a State of Charge (SOC) value.

12. The step of sequentially controlling the main switch is as follows: A method for operating a battery system according to claim 10, comprising the step of determining a priority for controlling a target battery based on one of a battery identifier, a state value, and a location.

13. The step of sequentially controlling the main switch is as follows: Steps include: switching the positive terminal main switch of the first target battery to the closed position; and A method for operating the battery system according to claim 10, further comprising the step of subsequently switching the positive electrode main switch of the second target battery to the closed state.

14. The aforementioned battery system The aforementioned plurality of batteries are connected in parallel to the respective positive terminal main switches of the batteries and further include a pre-charge circuit which includes a pre-charge resistor and a pre-charge switch for each battery, The step of sequentially controlling the main switch is as follows: The steps of switching the precharge switch of the first target battery to the closed state, and then switching the positive electrode main switch of the first target battery to the closed state; and A method for operating a battery system according to claim 10, further comprising the step of switching the precharge switch of the second target battery to the closed state, and then switching the positive electrode main switch of the second target battery to the closed state.

15. The step of sequentially controlling the main switch is as follows: The steps of switching the positive terminal main switch of the first target battery to the closed state, and then switching the precharge switch of the first target battery to the open state; and A method for operating a battery system according to claim 14, comprising the step of switching the precharge switch of the second target battery to the closed state at the time the precharge switch of the first target battery is switched to the open state.

16. A battery control device located within a battery system including multiple batteries that can be connected in parallel on a DC link, At least one processor; and Includes memory for storing at least one instruction executed through the at least one processor, The aforementioned at least one instruction, An instruction to select a target battery to be connected in parallel based on the state information of the aforementioned battery; and A battery control device including commands for sequentially controlling main switches located on each input / output path of the target battery so that the target battery is connected to the DC link at different times.

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