Battery system and operating method thereof

Abstract

A battery system according to an embodiment of the present invention may include: a plurality of batteries; and a battery control device configured to control a main switch disposed on an input / output path of each of the plurality of batteries such that the batteries are connected in parallel to a direct current (DC) link. Here, the battery control apparatus is further configured to select target batteries to be connected in parallel based on state information of the batteries, and control the target batteries to be connected in parallel while sequentially controlling respective main switches of the target batteries such that the target batteries are connected to the DC link at different times.

Description

TECHNICAL FIELD

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0038196, filed on March 20, 2024, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

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

[0003] A secondary battery, which can be recharged and reused, can be used as an energy source for small-sized devices such as mobile phones, tablet PCs, and vacuum cleaners, and also used as an energy source for medium-to-large-sized devices such as cars and energy storage systems (ESSs) for smart grids.

[0004] According to system requirements, a secondary battery can be 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 or a battery rack in which battery packs are electrically connected. For an energy storage system for a smart grid, a high-capacity battery system having a plurality of battery racks 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 the voltage difference. Here, in the case of a battery system including a plurality of racks connected in parallel, racks satisfying a predetermined voltage imbalance condition are connected in parallel to each other, and active balancing of the parallel-connected racks is performed, thereby resolving the voltage imbalance between the racks.

[0006] In general, a superior control device (e.g., a bank battery management system) can control a balancing target rack to be connected to a DC link at the same time by switching a main switch (e.g., a positive main contactor) of each of the racks to be balanced to a closed state. Here, due to insufficient capacity of a power supply device (e.g., a switched mode power supply) that supplies power to the main switch of each of the racks, a certain RBMS (rack battery management system) can be reset, thereby causing a communication error between the superior control device and the corresponding RBMS.

[0007] One of the prior art documents related to the present application is KR 10-2015-0025215. SUMMARY

[0008] TECHNICAL PROBLEM

[0009] To eliminate one or more problems of the related art, an embodiment of the present disclosure provides a battery system that prevents a communication error that can occur when battery balancing is performed.

[0010] To address the one or more issues in the related art, an embodiment of the disclosure also provides a method of operating a battery system.

[0011] To address the one or more issues in the related art, an embodiment of the disclosure also provides a battery control device located in a battery system.

[0012] Technical Solution

[0013] To achieve the object of the disclosure, a battery system according to an embodiment of the disclosure can include: a plurality of batteries; and a battery control device configured to control main switches disposed on input / output paths of each of the plurality of batteries such that the batteries are connected in parallel to a direct current (DC) link.

[0014] Here, the battery control device is further configured to select target batteries to be connected in parallel based on state information of the batteries, and to control the target batteries to be connected in parallel while sequentially controlling respective main switches of the target batteries such that the target batteries are connected to the DC link at different times.

[0015] The battery control device can be further configured to determine, as the target batteries, the batteries satisfying a predefined unbalance condition based on at least one of a voltage value or a state of charge (SOC) value.

[0016] The battery control device can be further configured to determine a priority for controlling the target batteries based on one of an identifier, a state value, and a location of the batteries.

[0017] The battery control device can be further configured to switch a positive main switch of a first target battery to a closed state and subsequently switch a positive main switch of a second target battery to the closed state.

[0018] The battery system can further include a pre-charge circuit, each of the pre-charge circuits being connected in parallel to a positive main switch of each of the plurality of batteries and including a pre-charge resistor and a pre-charge switch. Here, the battery control device can be further configured to: switch a pre-charge switch of a first target battery to a closed state and subsequently switch a positive main switch of the first target battery to the closed state; and subsequently, switch a pre-charge switch of a second target battery to the closed state and subsequently switch a positive main switch of the second target battery to the closed state.

[0019] The battery control device can be further configured to: switch a positive main switch of a first target battery to a closed state and subsequently switch a pre-charge switch of the first target battery to an open state; and switch a pre-charge switch of a second target battery to the closed state while the pre-charge switch of the first target battery is switched to the open state.

[0020] The battery control device can be further configured to switch the pre-charge switch and the negative main switch of the first target battery to the closed state and then switch the positive main switch of the first target battery to the closed state, and subsequently, switch the pre-charge switch and the negative main switch of the second target battery to the closed state and then switch the positive main switch of the second target battery to the closed state.

[0021] The battery control device can be further configured to switch the positive main switch of the first target battery to the closed state and then switch the pre-charge switch of the first target battery to the open state, and switch the pre-charge switch and the negative main switch of the second target battery to the closed state while the pre-charge switch of the first target battery is switched to the open state.

[0022] The battery can correspond to any one of a battery module, a battery pack, a battery rack, and a battery bank.

[0023] According to another embodiment of the disclosure, a method of operating a battery system by a battery control device located in the battery system including a plurality of batteries capable of being connected in parallel to a direct current (DC) link can include selecting target batteries as targets of the parallel connection based on state information of the plurality of batteries, and sequentially controlling main switches disposed on input / output paths of the respective target batteries such that the target batteries are connected to the DC link at different times.

[0024] The selecting of the target batteries can include determining, as the target batteries, batteries satisfying a pre-defined unbalance condition based on at least one of a voltage value or a state of charge (SOC) value.

[0025] The sequentially controlling of the main switches can include determining a priority for controlling the target batteries based on one of an identifier, a state value, and a location of the batteries.

[0026] The sequentially controlling of the main switches can include switching the positive main switch of the first target battery to the closed state and then switching the positive main switch of the second target battery to the closed state.

[0027] The battery system can further include a pre-charge circuit, each of the pre-charge circuits being connected in parallel to the positive main switch of each of the plurality of batteries and including a pre-charge resistor and a pre-charge switch. Here, the sequentially controlling of the main switches can include 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 subsequently, 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.

[0028] The sequentially controlling the main switches can include switching the positive main switch of the first target battery to a closed state and then switching the pre-charge switch of the first target battery to an open state, and switching the pre-charge switch of the second target battery to a closed state when the pre-charge switch of the first target battery is switched to the open state.

[0029] According to another embodiment of the present disclosure, a battery control apparatus in a battery system including a plurality of batteries capable of being connected in parallel to a direct current (DC) link can include at least one processor, and a memory configured to store at least one instruction executed by the at least one processor.

[0030] Here, the at least one instruction can include an instruction for selecting a target battery as a target of parallel connection based on state information of the batteries, and an instruction for sequentially controlling main switches disposed on input / output paths of the respective target batteries such that the target batteries are connected to the DC link at different times.

[0031] Advantageous Effects

[0032] According to an embodiment of the present disclosure, it is possible to prevent communication errors that can occur in a battery system when performing battery balancing by controlling the balancing target batteries to be connected to a direct current (DC) link with a time difference. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a block diagram of a general energy storage system.

[0034] Figure 2 is a block diagram illustrating a battery system according to an embodiment of the present invention.

[0035] Figure 3 is a circuit diagram for explaining an input / output path of a battery according to an embodiment of the present invention.

[0036] Figure 4 is a flowchart of a method of operating a battery system according to an embodiment of the present invention.

[0037] Figure 5 is a reference diagram for explaining a method of operating a battery system according to an embodiment of the present invention.

[0038] Figure 6 is a reference diagram for explaining a method of operating a battery system according to another embodiment of the present invention.

[0039] Figure 7 is a reference diagram for explaining a method of operating a battery system according to another embodiment of the present invention.

[0040] Figure 8is a block diagram of a battery control device according to an embodiment of the present application.

[0041] 100: battery

[0042] 200: battery control device DETAILED DESCRIPTION

[0043] The present application can be modified in various forms and has various embodiments, and specific embodiments thereof are shown in the drawings by way of example and will be described in detail below. It should be understood, however, that the present application is not limited to a particular embodiment, but rather, the present application will cover all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present application. Throughout the drawings, like reference numerals refer to like elements.

[0044] It should be understood that although terms such as first, second, A, B, etc. can be used in this document to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element can be called a second element, and similarly, a second element can be called a first element without departing from the scope of the present application. As used herein, the term "and / or" includes a combination of multiple associated listed items or any of the multiple associated listed items.

[0045] It should be understood that when an element is referred to as being "coupled" or "connected" to another element, it can be directly coupled or connected to the other element, or intervening elements can be present. In contrast, when an element is referred to as being "directly coupled" or "directly connected" to another element, there are no intervening elements present.

[0046] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", when used herein, specify the presence of stated features, integers, steps, operations, elements, components and / or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0047] Unless otherwise defined, all terms used in disclosing elements, components, items, materials or the like that are uniquely characterized are intended to include all of the specific and equivalent forms of the element, component, item, material or the like. Furthermore, unless otherwise noted, the terms "first", "second", "third", and the like, do not imply a chronological or sequential order, but are used for discrimination between two or more elements, components, items, materials or the like.

[0048] Some terms used herein are defined as follows.

[0049] A battery cell is a basic unit for storing electric power, and a battery module refers to an assembly in which a plurality of battery cells are electrically connected.

[0050] A battery rack refers to a system of a single structure assembled by connecting module units in series / parallel as set by a battery manufacturer, and can be monitored and controlled by a battery management device / system (BMS). The battery rack can include several battery modules and a battery protection unit or any other protection device. Here, depending on a device or system in which a battery is used, the battery module can also be referred to as a battery pack.

[0051] A battery bank refers to a large-scale battery rack system configured by connecting a plurality of battery racks in parallel. A bank BMS for the battery bank can monitor and control several rack BMSs, each of which manages a battery rack.

[0052] A battery assembly can include a plurality of electrically connected battery cells, and refers to an assembly used as a power supply source by being applied to a specific system or device. Here, the battery assembly can mean a battery module, a battery pack, a battery rack, or a battery bank, but the scope of the present invention is not limited to these entities.

[0053] A battery system controller (BSC) is a device that performs top-level control of a battery system including a battery bank-based system, which can also be used as a control device in a battery system having a plurality of bank levels.

[0054] A state of charge (SOC) refers to a current state of charge of a battery, expressed in percentage points [%], and a state of health (SOH) can be a current state of a battery compared to its ideal or original condition, expressed in percentage points [%].

[0055] Figure 1 is a block diagram of a general energy storage system.

[0056] In an energy storage system (ESS), a basic unit of a battery for storing energy or electric power is a battery cell. In general, a series / parallel combination of battery cells can form a battery module, and a plurality of battery modules can form a battery rack. In other words, a battery rack that is a series / parallel combination of battery modules can be a basic unit of a battery system. Here, depending on a device or system in which a battery is used, the battery module can be referred to as a battery pack.

[0057] Reference Figure 1The battery rack 10 can include a plurality of battery modules and a battery protection unit or any other protection device. The battery rack can be monitored and controlled by a rack battery management system (RBMS). The RBMS can monitor the current, voltage, and temperature of each battery rack to be managed, calculate the state of charge (SOC) of the battery based on the monitoring results, and control charging and discharging.

[0058] Meanwhile, the battery protection unit (BPU) is a device for protecting the battery from abnormal and fault currents in the battery rack. The BPU can include a main contactor (MC), a fuse, a circuit breaker (CB), or a disconnecting switch (DS). Here, the main contactor can include a positive main contactor and a negative main contactor. The BPU can control the battery system on a rack-by-rack basis by controlling the main contactor to turn on / off according to the control of the RBMS. The BPU can also protect the battery from short circuit currents by using a fuse when a short circuit occurs. Thus, the existing battery system can be controlled by a protection device such as the BPU or a switching device.

[0059] In addition, a battery system controller (BSC) 20 can be located in each battery section including a plurality of batteries, peripheral circuits, and devices in order to monitor and control objects such as voltage, current, temperature, and a circuit breaker. The battery system controller can be a top-level controller of a battery system of a library level including a plurality of battery racks, and also serves as a controller in a battery system having a plurality of library level structures.

[0060] In addition, a power conversion system (PCS) 40 installed in each battery section can perform actual charging / discharging based on a charge / discharge command from an energy management system (EMS) 30. The power conversion system can include a DC / AC inverter and a controller. Meanwhile, the output of each BPU can be connected to a power generation device (e.g., a photovoltaic system) and the PCS 40 connected to a power grid through a DC link (or a DC bus). In addition, the energy management system (EMS) 30 or a power management system (PMS) can overall control the energy storage system.

[0061] Figure 2 is a block diagram illustrating a battery system according to an embodiment of the present application.

[0062] Reference Figure 2 The battery system according to an embodiment of the present application can include a plurality of batteries 100 and a battery control device 200 configured to manage and control the plurality of batteries.

[0063] In the present application, the battery 100 can mean a battery rack, but the scope of the present application is not limited thereto. For example, the battery 100 can correspond to any one of a battery module, a battery pack, a battery rack, and a battery library.

[0064] The batteries 100 can be connected in parallel to each other. Here, the batteries 100 can be individually connected to a direct current (DC) link and thus connected in parallel to other batteries.

[0065] Each of the batteries 100 can include a main switch disposed on an input / output path. Here, the battery 100 can be connected or disconnected from the DC link by on / off control of the main switch.

[0066] Each of the batteries 100 can further include a pre-charge circuit disposed on the input / output path. Here, the pre-charge circuit can include a pre-charge resistor and a pre-charge switch connected in series.

[0067] Each of the batteries 100 can include a battery management device (BMS) therein. Here, the battery control device 200 can correspond to a superior control device connected to the battery management device of each of the batteries 100, and can correspond to, for example, a bank BMS (BBMS) connected to a plurality of RBMSs, a battery system controller (BSC), an energy management system (EMS), or a power management system (PMS).

[0068] The battery control device 200 can control the operation of the main switch of each of the batteries 100. In addition, the battery control device 200 can control the operation of the pre-charge switch of each of the batteries 100.

[0069] The battery control device 200 can collect state information of the batteries 100. Here, the state information can include one or more of a voltage value, a current value, an SOC value, and a temperature value of the battery.

[0070] The battery control device 200 can select a target battery connected in parallel. Here, the battery control device 200 can determine a battery that satisfies a pre-defined unbalance condition among the batteries 100 as the target battery.

[0071] The battery control device 200 can control the main switch and the pre-charge switch of the target battery so that the target batteries are connected in parallel to each other. Here, the battery control device 200 can control the operation of the main switch and the pre-charge switch of the target battery by transmitting a switch control signal to a battery management device (BMS) of the target battery.

[0072] Figure 3 is a circuit diagram for explaining an input / output path of a battery according to an embodiment of the present application.

[0073] Each of the batteries 100 can include a plurality of battery cells 110 and a main switch disposed on an input / output path.

[0074] The main switch of the battery 100 can include a positive main switch 121 arranged on the positive line. Here, when the positive main switch 121 is switched from an off (open) state to an on (closed) state, it is electrically connected to the DC link so that the battery 100 can be connected in parallel with another battery. In contrast, when the positive main switch 121 is switched from an on (closed) state to an off (open) state, the electrical connection to the DC link is cut off so that the parallel connection between the battery 100 and another battery can be released.

[0075] The main switch of the battery 100 can also include a negative main switch 122 arranged on the negative line. Here, when the positive main switch 121 and the negative main switch 122 are switched from an open state to a closed state, they are electrically connected to the DC link so that the battery 100 can be connected in parallel with another battery. In contrast, when either of the positive main switch 121 and the negative main switch 122 is switched from a closed state to an open state, the electrical connection to the DC link is cut off so that the parallel connection between the battery 100 and another battery can be released.

[0076] Each of the batteries 100 can also include a pre-charge circuit arranged on the input / output path. Here, the pre-charge circuit is connected in parallel with the positive main switch 121 and can include a pre-charge resistor 124 and a pre-charge switch 123 connected in series. Here, when the pre-charge switch 123 and the negative main switch 122 are switched from an open state to a closed state and then the positive main switch 121 is switched from an open state to a closed state, the battery 100 can be connected in parallel with another battery. Thereafter, the pre-charge switch 123 can be switched from a closed state to an open state.

[0077] The battery control device 200 can determine a battery that satisfies a predefined unbalance condition among a plurality of batteries 100 as a target battery, and control the positive main switch 121, the negative main switch 122, and the pre-charge switch 123 of each target battery so that the target batteries are connected in parallel with each other. Here, the battery control device 200 can control the on / off operation of the positive main switch 121, the negative main switch 122, and the pre-charge switch 123 of the target batteries by transmitting a switch control signal to a battery management device (BMS) of each of the target batteries.

[0078] Figure 4 is a flowchart of a method of operating a battery system according to an embodiment of the present invention.

[0079] The operation method of the battery system according to the embodiment of the present application can be performed by a battery control device located in the battery system. Here, the battery control device 200 can correspond to a superior control device connected with a battery management device of each of the batteries 100, and can correspond to, for example, a bank BMS (BBMS) connected with a plurality of RBMSs, a battery system controller (BSC), an energy management system (EMS), or a power management system (PMS).

[0080] The battery control device can select a target battery as a target (or a balancing target) to be connected in parallel among the plurality of batteries (S410). Here, the battery control device can determine a battery satisfying a predefined unbalance condition as the target battery.

[0081] In an embodiment, the unbalance condition can be predefined based on one or more of the voltage values and the SOC values. For example, the unbalance condition can be defined as a battery exhibiting a difference equal to or greater than a threshold range from a predefined reference voltage value (or a reference SOC value). Meanwhile, the unbalance condition can be defined in various ways as a condition for selecting a battery as a balancing target as needed.

[0082] The battery control device can perform active balancing on the target battery by connecting the target battery selected in S410 in parallel (S420) (S430).

[0083] Here, the battery control device can sequentially control the main switch of each of the target batteries with a time difference such that the target batteries are connected to the DC link at different times.

[0084] The battery control device can determine a priority of the sequential control on the target batteries. Here, the battery control device can determine the control priority based on one of an identifier of the battery, a state value of the battery, and a location of the battery.

[0085] For example, the battery control device can check a predefined identification number of each of the target batteries, and sequentially assign the priority starting from the battery having a lower identification number.

[0086] As another example, the battery control device can check a state value (e.g., a voltage value or an SOC value) of each of the target batteries, and sequentially assign the priority starting from the battery having a smaller difference from a reference state value.

[0087] As another example, the battery control device can check a predefined location identifier of each of the target batteries, and sequentially assign the priority starting from the battery closest to the PCS.

[0088] The battery control device can sequentially control the main switches of the target batteries according to the priorities 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 main switch of a first target battery (a target battery having an Nth priority) to the closed state, and then switch the positive main switch of a second target battery (a target battery having an N+1th priority) to the closed state, so that the first target battery and the second target battery are connected to the DC link with a time difference. Thus, communication errors in the battery system due to lack of capacity of the power supply device supplying power to the switches of each battery can be prevented.

[0089] Figure 5 is a reference diagram for explaining a method of operating a battery system according to an embodiment of the present application. Hereinafter, with reference to Figure 5 , an embodiment of a method of operating a battery system in which a positive main switch and a pre-charge circuit are provided on an input / output path of a battery and a negative main switch is not provided will be described.

[0090] The battery control device can sequentially connect the target batteries selected as balancing targets to the DC link in parallel according to the priorities.

[0091] Here, the battery control device can switch the pre-charge switch (SW_pc) of a first target battery (a target battery having an Nth priority) to the on (closed) state, and then switch the positive main switch (MSW_p) of the first target battery to the on (closed) state.

[0092] Thereafter, the battery control device can switch the pre-charge switch (SW_pc) of a second target battery (a target battery having an N+1th priority) to the on (closed) state, and then switch the positive main switch (MSW_p) of the second target battery to the on (closed) state.

[0093] For example, as shown in Figure 5 , if batteries #1, #3, and #5 among a plurality of batteries are selected as target batteries, and the control priorities can be determined in the order of batteries #1, #3, and #5, the battery control device can switch the pre-charge switch (SW_pc) of battery #1 to the on (closed) state, then switch the positive main switch (MSW_p) of battery #1 to the on (closed) state, and then switch the pre-charge switch (SW_pc) of battery #1 to the off (open) state.

[0094] Thereafter, the battery control device can sequentially control the pre-charge switches (SW_pc) and the positive main switches (MSW_p) of batteries #3 and #5, respectively, as shown in Figure 5 , so that batteries #1, #3, and #5 are sequentially connected to the DC link.

[0095] If the switching time of each switch is 1 second, the batteries #1, #3, and #5 can be connected to the DC link at 2 seconds, 5 seconds, and 8 seconds (at the time when MSW_p is closed), respectively, after the initiation of the balancing control.

[0096] Figure 6 is a reference diagram for explaining a method of operating a battery system according to another embodiment of the present application. Hereinafter, the method of operating a battery system described in Figure 6 another embodiment different from the method of operating a battery system described in Figure 5 will be explained.

[0097] The battery control device can sequentially connect the target batteries selected as the balancing targets to the DC link in parallel according to the priorities.

[0098] Here, the battery control device can switch the pre-charge switch (SW_pc) of the first target battery (the target battery of the Nth priority) to the on (closed) state, and then switch the positive main switch (MSW_p) of the first target battery to the on (closed) state. Thereafter, the battery control device can switch the pre-charge switch (SW_pc) of the first target battery to the off (open) state.

[0099] Thereafter, the battery control device can switch the pre-charge switch (SW_pc) of the second target battery (the target battery of the N+1th priority) to the on (closed) state, and then switch the positive main switch (MSW_p) of the second target battery to the on (closed) state. Thereafter, the battery control device can switch the pre-charge switch (SW_pc) of the second target battery to the off (open) state.

[0100] Here, the battery control device can switch the pre-charge switch (SW_pc) of the second target battery to the on (closed) state at the time when the pre-charge switch (SW_pc) of the first target battery is switched to the off (open) state.

[0101] For example, as shown in Figure 6 If the batteries #1, #3, and #5 among a plurality of batteries are selected as the target batteries, and the control priorities are determined in the order of the batteries #1, #3, and #5, the battery control device can switch the pre-charge switch (SW_pc) of the battery #1 to the on (closed) state, then switch the positive main switch (MSW_p) of the battery #1 to the on (closed) state, and then switch the pre-charge switch (SW_pc) of the battery #1 to the off (open) state.

[0102] Thereafter, the battery control device can sequentially control the pre-charge switch (SW_pc) and the positive main switch (MSW_p) of the battery #3 as in the battery #1, so that the batteries #1 and #3 are sequentially connected to the DC link. Here, the battery control device can switch the pre-charge switch (SW_pc) of the battery #3 to the on (closed) state at the time when the pre-charge switch (SW_pc) of the battery #1 is switched to the off (open) state.

[0103] Similarly, the battery control device can sequentially control the pre-charge switch (SW_pc) and the positive main switch (MSW_p) of the battery #5 as in the batteries #1 and #3, but can switch the pre-charge switch (SW_pc) of the battery #5 to the on (closed) state at the time when the pre-charge switch (SW_pc) of the battery #3 is switched to the off (open) state.

[0104] If the switching time of each switch is 1 second, the batteries #1, #3 and #5 can be connected to the DC link at 2 seconds, 4 seconds and 6 seconds (at the time when the MSW_p is closed) after the initiation of the balancing control, respectively.

[0105] If the switches included in the batteries correspond to relays, the power supply of the power supply device is unnecessary when the relays are switched to the off (open) state. Therefore, as shown in Figure 6 If the simultaneous control of the first target battery and the second target battery is performed in the control section in which the pre-charge switch (SW_pc) is switched to the off (open) state, the parallel connection time of the target batteries can be shortened, as shown in

[0106] Figure 7 is a reference diagram for explaining an operation method of a battery system according to another embodiment of the present application. Hereinafter, with reference to Figure 7 An operation method of a battery system in which a positive main switch, a negative main switch and a pre-charge circuit are provided on an input / output path of a battery will be described.

[0107] The battery control device can sequentially connect target batteries selected as balancing targets to the DC link in accordance with priorities.

[0108] Here, the battery control device can switch the pre-charge switch (SW_pc) and the negative main switch (MSW_n) of the first target battery (the target battery of the Nth priority) to the on (closed) state, and then switch the positive main switch (MSW_p) of the first target battery to the on (closed) state. Thereafter, the battery control device can switch the pre-charge switch (SW_pc) of the first target battery to the off (open) state.

[0109] Thereafter, the battery control device can switch the pre-charge switch (SW_pc) and the negative main switch (MSW_n) of the second target battery (target battery having the (N+l)th priority) to the on (closed) state, and then switch the positive main switch (MSW_p) of the second target battery to the on (closed) state. Thereafter, the battery control device can switch the pre-charge switch (SW_pc) of the second target battery to the off (open) state.

[0110] Here, the battery control device can switch the pre-charge switch (SW_pc) and the negative main switch (MSW_n) of the second target battery to the on (closed) state at the time when the pre-charge switch (SW_pc) of the first target battery is switched to the off (open) state.

[0111] For example, as shown in FIG. 5, if the batteries #1, #3, and #5 among the plurality of batteries are selected as the target batteries and the control priority is determined in the order of the batteries #1, #3, and #5, the battery control device can transition the pre-charge switch (SW_pc) and the negative main switch (MSW_n) of the battery #1 to the on (closed) state, then transition the positive main switch (MSW_p) of the battery #1 to the on (closed) state, and then transition the pre-charge switch (SW_pc) of the battery #1 to the off (open) state. Figure 7

[0112] Thereafter, the battery control device can sequentially control the pre-charge switch (SW_pc), the positive main switch (MSW_p), and the negative main switch (MSW_n) of the battery #3 as with the battery #1, so that the batteries #1 and #3 are sequentially connected to the DC link. Here, the battery control device can switch the pre-charge switch (SW_pc) and the negative main switch (MSW_n) of the battery #3 to the on (closed) state at the time when the pre-charge switch (SW_pc) of the battery #1 is switched to the off (open) state.

[0113] Similarly, the battery control device can sequentially control the pre-charge switch (SW_pc), the positive main switch (MSW_p), and the negative main switch (MSW_n) of the battery #5 as with the batteries #1 and #3, but can switch the pre-charge switch (SW_pc) and the negative main switch (MSW_n) of the battery #5 to the on (closed) state at the time when the pre-charge switch (SW_pc) of the battery #3 is switched to the off (open) state.

[0114] Figure 8 is a block diagram of a battery control device according to an embodiment of the present application.

[0115] ​The battery control apparatus 800 according to embodiments of the present application can be located in a battery system including a plurality of batteries which can be connected in parallel on a DC link, and can be linked with a battery management device of each battery. For example, if a battery corresponds to a rack, the battery control apparatus 800 can correspond to a bank BMS (BBMS) connected with a plurality of RBMSs, a battery system controller (BSC), an energy management system (EMS), or a power management system (PMS).

[0116] The battery control apparatus 800 can include at least one processor 810, a memory 820 storing at least one instruction executed by the processor, and a transceiver 830 connected to a network and performing communication.

[0117] The at least one instruction can include an instruction for selecting a target battery as a target of parallel connection based on state information of the battery, and an instruction for sequentially controlling master switches located on input / output paths of each target battery such that the target batteries are connected to the DC link at different times.

[0118] The instruction for selecting the target battery includes an instruction for determining a battery satisfying a predefined unbalance condition as the target battery based on at least one of a voltage value or a state of charge (SOC) value.

[0119] The instruction for sequentially controlling the master switches includes an instruction for determining a priority for controlling the target battery based on one of an identifier, a state value, and a location of the battery.

[0120] The instruction for sequentially controlling the master switches includes an instruction for switching a positive master switch of a first target battery to a closed state, and an instruction for subsequently switching a positive master switch of a second target battery to a closed state.

[0121] The battery system can further include a pre-charge circuit, each of the pre-charge circuits being connected in parallel with a positive master switch of each battery of the plurality of batteries and including a pre-charge resistor and a pre-charge switch. Here, the instruction for sequentially controlling the master switches includes an instruction for switching a pre-charge switch of a first target battery to a closed state and then an instruction for switching a positive master switch of the first target battery to a closed state, and an instruction for subsequently switching a pre-charge switch of a second target battery to a closed state and then a positive master switch of the second target battery to a closed state.

[0122] The instruction for sequentially controlling the master switches includes an instruction for switching a positive master switch of a first target battery to a closed state and then a pre-charge switch of the first target battery to an open state, and an instruction for switching a pre-charge switch of a second target battery to a closed state while the pre-charge switch of the first target battery is switched to the open state.

[0123] The battery control device 800 may also include an input interface device 840, an output interface device 850, a storage device 860, etc. The corresponding components included in the battery control device 800 can be connected via a bus 870 and can communicate with each other.

[0124] Here, processor 810 may be a central processing unit (CPU), graphics processing unit (GPU), or dedicated processor on which the methods according to embodiments of the present invention are executed. The memory (or storage unit) may include at least one of volatile storage media and non-volatile storage media. For example, the memory may include at least one of read-only memory (ROM) and random access memory (RAM).

[0125] The operation of the method according to embodiments of the present invention can be implemented as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes all types of recording devices in which computer systems store data readable by the computer. Furthermore, the computer-readable recording medium can be distributed across network-connected computer systems, thereby storing and executing the computer-readable program or code in a distributed manner.

[0126] Although some aspects of the invention have been described in the context of the apparatus, they may also refer to, according to the description of the corresponding method, a block or device corresponding to a method step or feature of a method step. Similarly, aspects described in the context of a method may also refer to features of corresponding blocks or items or corresponding devices. Some or all of the method steps may be performed by (or using) hardware devices such as, for example, microprocessors, programmable computers, or electronic circuits. In some embodiments, one or more of the most important method steps may be performed by such devices.

[0127] In the foregoing, the present invention has been described with reference to exemplary embodiments thereof; however, those skilled in the art will appreciate that the invention may be modified and altered in various ways without departing from the spirit and scope of the invention as described in the appended claims.

Claims

1. A battery system, comprising: Multiple batteries; as well as A battery control device configured to control a main switch on the input / output path of each of the plurality of batteries, such that the batteries are connected in parallel to a DC link. The battery control device is further configured to select a target battery to be connected in parallel based on the battery's state information, and to control the target battery to be connected in parallel while sequentially controlling the corresponding main switch of the target battery, so that the target battery is connected to the DC link at different times.

2. The system according to claim 1, wherein, The battery control device is also configured to identify a battery that meets a predefined imbalance condition as a target battery based on at least one of a voltage value or a state of charge (SOC) value.

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

4. The system according to claim 1, wherein, The battery control device is also configured to switch the positive main switch of the first target battery to the closed state and subsequently switch the positive main switch of the second target battery to the closed state.

5. The system according to claim 1, further comprising: A pre-charge circuit, wherein each pre-charge circuit is connected in parallel with the positive main switch of each of the plurality of batteries and includes a pre-charge resistor and a pre-charge switch. The battery control device is further configured as follows: Switch the pre-charge switch of the first target battery to the closed state, and then switch the positive main switch of the first target battery to the closed state; and Subsequently, the precharge switch of the second target battery is switched to the closed state, and then the positive main switch of the second target battery is switched to the closed state.

6. The system according to claim 5, wherein, The battery control device is also configured to: Switch the positive main switch of the first target battery to the closed state, and then switch the precharge switch of the first target battery to the open state; as well as When the precharge switch of the first target battery is switched to the off state, the precharge switch of the second target battery is switched to the closed state.

7. The system according to claim 5, wherein, The battery control device is also configured to: Switch the precharge switch and negative main switch of the first target battery to the closed state, and then switch the positive main switch of the first target battery to the closed state. as well as Subsequently, the pre-charge switch and negative main switch of the second target battery are switched to the closed state, and then the positive main switch of the second target battery is switched to the closed state.

8. The system according to claim 7, wherein, The battery control device is also configured to: Switch the positive main switch of the first target battery to the closed state, and then switch the precharge switch of the first target battery to the open state; as well as When the precharge switch of the first target battery is switched to the off state, the precharge switch and the negative main switch of the second target battery are switched to the closed state.

9. The system according to claim 1, wherein, The battery corresponds to any one of the battery module, battery pack, battery rack, and battery bank.

10. A method of operating a battery system via a battery control device located in the battery system, the battery system comprising a plurality of batteries capable of being connected in parallel to a DC link, the method comprising: Based on the state information of the multiple batteries, a target battery is selected as the target for parallel connection; as well as The main switches arranged on the input / output paths of the corresponding target batteries are controlled sequentially, so that the target batteries are connected to the DC link at different times.

11. The method according to claim 10, wherein, Selecting the target battery includes: Batteries that meet predefined imbalance conditions are identified as target batteries based on at least one of voltage value or state of charge (SOC) value.

12. The method according to claim 10, wherein, Sequential control of the main switch includes: The priority for controlling the target battery is determined based on one of the battery's identifier, state value, and location.

13. The method according to claim 10, wherein, Sequential control of the main switch includes: Switch the main switch of the first target battery to the closed state; and Then the main switch of the second target battery was switched to the closed state.

14. The method of claim 10, wherein, The battery system further includes pre-charge circuits, each of which is connected in parallel with the positive main switch of each of the plurality of batteries and includes a pre-charge resistor and a pre-charge switch. The sequential control of the main switch includes: Switch the pre-charge switch of the first target battery to the closed state, and then switch the positive main switch of the first target battery to the closed state; and Subsequently, the precharge switch of the second target battery is switched to the closed state, and then the positive main switch of the second target battery is switched to the closed state.

15. The method according to claim 14, wherein, Sequential control of the main switch includes: Switch the positive main switch of the first target battery to the closed state, and then switch the pre-charge switch of the first target battery to the open state; and When the precharge switch of the first target battery is switched to the off state, the precharge switch of the second target battery is switched to the closed state.

16. A battery control device located in a battery system, the battery system comprising a plurality of batteries capable of being connected in parallel to a DC link, the device comprising: At least one processor; as well as A memory configured to store at least one instruction executed by the at least one processor. Wherein, the at least one instruction includes: Instructions for selecting a target battery as a parallel connection target based on the battery's state information; and Instructions for sequentially controlling the main switches arranged on the input / output paths of the respective target batteries so that the target batteries are connected to the DC link at different times.

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