Battery system and operating method thereof

Abstract

A battery system according to an embodiment of the present invention may comprise: a plurality of batteries; and a battery control device for controlling a main switch arranged on an input / output path of each of the plurality of batteries, so that the batteries are controlled to be connected in parallel to a DC link. Here, the battery control device may select target batteries to be connected in parallel, on the basis of the state information of the batteries, and control the target batteries to be connected in parallel such that the target batteries are connected to the DC link at different time points by sequentially controlling main switches of the respective target batteries.

Description

Battery system and method of operation thereof

[0001] This application claims the benefit of Korean Patent Application No. 10-2024-0038196 filed with the Korean Intellectual Property Office on March 20, 2024, the entire disclosure of which is incorporated herein by reference.

[0002] The present invention relates to a battery system and a method of operating the same, and more particularly, to a battery system including a battery control device that controls a main switch of each battery and a method of operating the same.

[0003] Secondary batteries are batteries that can be reused by 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 are also used as an energy source for medium and large devices such as automobiles and ESS (Energy Storage Systems) for smart grids.

[0004] Secondary batteries are applied to systems in the form of assemblies, such as battery packs, where multiple battery cells are electrically connected, or battery racks, where multiple battery packs are electrically connected, depending on the system requirements. For ESS for smart grids, high-capacity battery systems, where multiple battery racks are connected in parallel, can be applied to meet the system's capacity requirements.

[0005] When voltage differences occur between battery racks during battery system operation, rack balancing control is performed to minimize these voltage differences. In a battery system comprising multiple parallel-connected racks, racks that meet predefined voltage imbalance conditions are connected in parallel, and active balancing of the parallel-connected racks is performed, thereby resolving the voltage imbalance between the racks.

[0006] Typically, a higher-level control device (e.g., Bank Battery Management System) can control the main switches (e.g., positive main contactors) of each of the racks to be balanced to be closed, so that the racks to be balanced are simultaneously connected to the DC link. At this time, a specific Rack Battery Management System (RBMS) may be reset due to insufficient capacity of a power supply device (e.g., Switching Mode Power Supply) that supplies power to the main switches of each of the racks, resulting in a communication error between the higher-level control device and the specific RBMS.

[0007] As a prior art document related to the present invention, there is KR 10-2015-0025215.

[0008] The purpose of the present invention to solve the above problems is to provide a battery system that prevents communication errors that may occur when performing battery balancing.

[0009] Another object of the present invention to solve the above problems is to provide a method for operating such a battery system.

[0010] Another object of the present invention to solve the above problems is to provide a battery control device located within such a battery system.

[0011] According to one embodiment of the present invention to achieve the above object, a battery system may include a plurality of batteries; and a battery control device that controls a main switch disposed on an 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 selects target batteries to be connected in parallel based on status information of the batteries, and controls the target batteries to be connected in parallel, while sequentially controlling the main switch of each of the target batteries so that the target batteries are connected to the DC link at different times.

[0013] The above battery control device can determine a battery that satisfies a predefined imbalance condition based on at least one of a voltage value and a SOC (State Of Charge) value as the target battery.

[0014] The battery control device can determine a priority for controlling the target batteries based on one of the identifier, status value, and location of the battery.

[0015] The above battery control device can switch the positive main switch of the first target battery to the closed state, and then switch the positive main switch of the second target battery to the closed state.

[0016] The battery system may further include precharge circuits, each of which is connected in parallel with the positive main switch of each of the plurality of batteries and each of which includes a precharge resistor and a precharge switch. Here, the battery control device may switch the positive 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. Thereafter, the battery control device may switch the positive 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 can switch the positive main switch of the first target battery to a closed state, then switch the pre-charge switch of the first target battery to an open state, and switch the pre-charge switch of the second target battery to a closed state at the time when the pre-charge switch of the first target battery is switched to an open state.

[0018] The battery control device may switch the precharge 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. Thereafter, the battery control device may switch the precharge 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.

[0019] The battery control device can switch the positive main switch of the first target battery to a closed state, then switch the pre-charge switch of the first target battery to an open state, and switch the pre-charge switch and the negative main switch of the second target battery to a closed state at the time when the pre-charge switch of the first target battery is switched to an open state.

[0020] The above battery may correspond to any one of a battery module, a battery pack, a battery rack, and a battery bank.

[0021]

[0022] According to one embodiment of the present invention for achieving the above other object, a method for operating a battery system is provided, 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 including the steps of: selecting target batteries that are objects of parallel connection based on status information of the batteries; and sequentially controlling a main switch located on an input / output path of each of the target batteries so that the target batteries are connected to the DC link at different times.

[0023] The step of selecting the target batteries may include a step of determining a battery that satisfies a predefined imbalance condition based on at least one of a voltage value and a SOC (State Of Charge) value as the target battery.

[0024] The step of sequentially controlling the main switch may include a step of determining a priority for controlling the target batteries based on one of the identifier, status value, and position of the battery.

[0025] The step of sequentially controlling the main switches may include a step of switching the positive main switch of the first target battery to a closed state; and thereafter, a step of switching the positive main switch of the second target battery to a closed state.

[0026] The battery system may further include precharge circuits connected in parallel with the positive main switches of each of the plurality of batteries, each of which includes a precharge resistor and a precharge switch. Here, the step of sequentially controlling the main switches may include the step of switching the precharge switch of the first target battery to a closed state, and then switching the positive main switch of the first target battery to a closed state; and thereafter, the step of switching the precharge switch of the second target battery to a closed state, and then switching the positive main switch of the second target battery to a closed state.

[0027] The step of sequentially controlling the main switches may include the step of 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 the step of switching the pre-charge switch of the second target battery to a closed state at the time when the pre-charge switch of the first target battery is switched to an open state.

[0028]

[0029] According to one embodiment of the present invention for achieving the above another object, a battery control device is provided, which is located in a battery system including a plurality of batteries that can be connected in parallel on a DC link, and may include at least one processor; and a memory that stores at least one command executed through the at least one processor.

[0030] Here, the at least one command may include a command for selecting target batteries to be connected in parallel based on status information of the batteries; and a command for sequentially controlling a main switch arranged on an input / output path of each of the target batteries so that the target batteries are connected to the DC link at different times.

[0031] According to the above-described embodiment of the present invention, by controlling the balancing target batteries to be connected to the DC link at different times, communication errors within the battery system that may occur when performing battery balancing can be prevented.

[0032] Figure 1 is a block diagram of a typical energy storage system.

[0033] Figure 2 is a block diagram of a battery system according to an embodiment of the present invention.

[0034] Figure 3 is a circuit diagram for explaining the input / output path of a battery according to an embodiment of the present invention.

[0035] Figure 4 is an operational flowchart of a method for operating a battery system according to an embodiment of the present invention.

[0036] Figure 5 is a reference diagram for explaining an operating method of a battery system according to an embodiment of the present invention.

[0037] FIG. 6 is a reference diagram for explaining an operating method of a battery system according to another embodiment of the present invention.

[0038] FIG. 7 is a reference diagram for explaining an operating method of a battery system according to another embodiment of the present invention.

[0039] Figure 8 is a block diagram of a battery control device according to an embodiment of the present invention.

[0040] 100: Battery

[0041] 200: Battery control unit

[0042] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. Throughout the description of each drawing, similar reference numerals have been used to designate similar components.

[0043] Terms such as "first," "second," "A," and "B" may be used to describe various components, but these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, the first component could be referred to as the "second component," and similarly, the second component could also be referred to as the "first component." The term "and / or" includes any combination of multiple related items listed or any one of multiple related items listed.

[0044] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0045] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0046] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0047]

[0048] Some terms used in this specification are defined as follows:

[0049] A battery cell is the smallest unit that stores electricity, and a battery module is a collection of multiple battery cells that are electrically connected.

[0050] A battery rack is a single-structure system that connects module units specified by the battery manufacturer in series or parallel, enabling monitoring and control via a Battery Management System (BMS). It can be configured to include multiple battery modules and a single BPU or protection device. Depending on the device or system in which the battery is used, the battery module may also be referred to as a battery pack.

[0051] A battery bank can refer to a large-scale battery rack system composed of multiple racks connected in parallel. A battery bank-level BMS (BBMS) can monitor and control the rack BMS (RBMS) at the battery rack level.

[0052] A battery assembly is a collection of multiple electrically connected battery cells that function as a power source when applied to a specific system or device. Here, the battery assembly may refer to a battery module, battery pack, battery rack, or battery bank, but the scope of the present invention is not limited to these entities.

[0053] BSC (Battery System Controller) is a device that performs top-level control of a battery system, including a battery bank unit battery system, and is also used as a control device in a battery system with multiple bank level structures.

[0054] SOC (State of Charge) is the current charged state of the battery expressed as a percentage [%], and SOH (State of Health) is the current remaining state of the battery expressed as a percentage [%].

[0055]

[0056] Figure 1 is a block diagram of a typical energy storage system.

[0057] In an energy storage system (ESS), the smallest unit of a battery that stores power is typically a battery cell. A series / parallel combination of battery cells forms a battery module, and multiple battery modules can form a battery rack. In other words, a battery rack, consisting of a series / parallel combination of battery modules, can serve as the smallest unit of a battery system. Depending on the device or system in which the battery is used, a battery module may also be referred to as a battery pack.

[0058] Referring to Fig. 1, a single battery rack (10) may include multiple battery modules and a single BPU or protection device. The battery rack can be monitored and controlled through a Rack Battery Management System (RBMS). The RBMS monitors the current, voltage, and temperature of each battery rack under its control, and based on the monitoring results, calculates the battery's SOC (Status Of Charge) and controls charging and discharging.

[0059] Meanwhile, the Battery Protection Unit (BPU) is a device that protects batteries from abnormal current and fault current at the rack level. The BPU may include a main contactor (MC), a fuse, a circuit breaker (CB), or a disconnect switch (DS). The main contactor may include a positive main contactor and a negative main contactor. The BPU can control the battery system at the rack level by turning the main contactor on and off under the control of the RBMS. The BPU can also protect the battery from short-circuit current using a fuse in the event of a short-circuit. In this way, existing battery systems can be controlled through protective devices such as the BPU and switch gear.

[0060] Meanwhile, each battery section, which is composed of a plurality of batteries and peripheral circuits, devices, etc., is equipped with a BSC (Battery System Controller) (20) to monitor and control control targets such as voltage, current, temperature, circuit breakers, etc. The BSC is the top-level control device of a battery system including a bank-level battery system including a plurality of battery racks, and is also used as a control device in a battery system having a multiple bank-level structure.

[0061] In addition, the power conversion system (PCS) (40) installed in each battery section is a device that performs actual charging / discharging based on the charging / discharging command from the EMS (30), and may be configured to include a power conversion unit (DC / AC inverter) and a controller. Meanwhile, the output of each BPU may 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) may be connected to the grid. In addition, the EMS (Energy Management System) (30) or PMS (Power Management System) manages the ESS system as a whole.

[0062]

[0063] Figure 2 is a block diagram of a battery system according to an embodiment of the present invention.

[0064] Referring to FIG. 2, a battery system according to an embodiment of the present invention may include a plurality of batteries (100) and a battery control device (200) that manages and controls the plurality of batteries.

[0065] In the present invention, the battery (100) may refer to a battery rack, but the scope of the present invention is not limited thereto. For example, the battery (100) may correspond to any one of a battery module, a battery pack, a battery rack, and a battery bank.

[0066] The batteries (100) can be connected in parallel with each other. Here, the batteries (100) can be individually connected to a DC link and connected in parallel with other batteries.

[0067] Each of the batteries (100) may include a main switch positioned on the input / output path. Here, the battery (100) may be connected or disconnected from the DC link by on / off control of the main switch.

[0068] Each of the batteries (100) may further include a precharge circuit arranged on an input / output path. Here, the precharge circuit may include a series-connected precharge resistor and a precharge switch.

[0069] Each of the batteries (100) may include a battery management system (BMS) within it. Here, the battery control device (200) may correspond to an upper control device that interfaces with the battery management devices of each of the batteries (100), and may correspond to, for example, a BBMS, BSC, EMS, or PMS that interfaces with a plurality of RBMSs.

[0070]

[0071] 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 precharge switch of each of the batteries (100).

[0072] The battery control device (200) can collect status information of batteries (100). Here, the status information can include one or more of a voltage value, a current value, a SOC value, and a temperature of the battery.

[0073] The battery control device (200) can select target batteries to be connected in parallel. Here, the battery control device (200) can determine a battery that satisfies a predefined imbalance condition among the batteries (100) as a target battery.

[0074] The battery control device (200) can control the main switch and precharge switch of the target batteries so that the target batteries are connected in parallel. Here, the battery control device (200) can control the operation of the main switch and precharge switch of the target battery by transmitting a switch control signal to the BMS of the target battery.

[0075]

[0076] Figure 3 is a circuit diagram for explaining the input / output path of a battery according to an embodiment of the present invention.

[0077] Each of the batteries (100) may include a plurality of battery cells (110) and a main switch arranged on an input / output path.

[0078] The main switch of the battery (100) may 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. Conversely, when the positive main switch (121) is switched from an on (closed) state to an off (open) state, the electrical connection of the DC link is cut off, so that the parallel connection between the battery (100) and another battery can be released.

[0079] The main switch of the battery (100) may further 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. Conversely, when either one 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 of the DC link is cut off, so that the parallel connection between the battery (100) and the other battery can be released.

[0080] Each of the batteries (100) may further include a precharge circuit arranged on an input / output path. Here, the precharge circuit may include a precharge resistor (124) and a precharge switch (123) that are connected in parallel with the positive main switch (121) and are connected in series. Here, when the precharge 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) may be connected in parallel with another battery. Thereafter, the precharge switch (123) may be switched from a closed state to an open state.

[0081] The battery control device (200) determines batteries that satisfy a predefined imbalance condition among a plurality of batteries (100) as target batteries, and controls the positive main switch (121), the negative main switch (122), and the precharge switch (123) of the target batteries so that the target batteries are connected in parallel. 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 precharge switch (123) of the target batteries by transmitting a switch control signal to the BMS of each of the target batteries.

[0082]

[0083] Figure 4 is an operational flowchart of a method for operating a battery system according to an embodiment of the present invention.

[0084] The method for operating a battery system according to an embodiment of the present invention may be performed by a battery control device located within the battery system. Here, the battery control device may correspond to an upper control device that interfaces with the battery management devices of each battery, and may correspond to, for example, a BBMS, BSC, EMS, or PMS that interfaces with multiple RBMSs.

[0085] The battery control device can select target batteries 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.

[0086] In an embodiment, an imbalance condition may be predefined based on one or more of a voltage value or a SOC value. For example, an imbalance condition may be defined as a battery exhibiting a difference exceeding a threshold range from a predefined reference voltage value (or reference SOC value). Meanwhile, an imbalance condition, which serves as a condition for selecting a battery to be balanced, may be defined in various ways as needed.

[0087] The battery control device can perform active balancing on the target batteries by connecting the target batteries selected in S410 in parallel (S420) (S430).

[0088] Here, the battery control device can sequentially control the main switch of each target battery with a time difference so that the target batteries are connected to the DC link at different times.

[0089] The battery control device can determine the priority for sequential control of target batteries. Here, the battery control device can determine the control priority based on one of the battery identifier, status value, and location.

[0090] For example, the battery control device can check a predefined identification number for each target battery and sequentially prioritize batteries starting with a lower identification number.

[0091] As another example, the battery control device can check the status value (e.g., voltage value or SOC value) for each target battery and sequentially give priority to the battery with a smaller difference from the reference status value.

[0092] As another example, the battery control unit may check a predefined location identifier for each of the target batteries and sequentially prioritize the batteries closest to the PCS.

[0093] 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 close the positive main switch of the first target battery (the target battery of the Nth priority) and then close the positive main switch of the second target battery (the target battery of the N+1th priority) so that the first target battery and the second target battery are connected to the DC link at different times. Accordingly, a communication error within the battery system due to insufficient capacity of the power supply device that supplies power to the switches of each of the batteries can be prevented.

[0094]

[0095] FIG. 5 is a reference diagram for explaining an operating method of a battery system according to an embodiment of the present invention. Hereinafter, with reference to FIG. 5, an embodiment of an operating method of a battery system will be described in which a positive main switch and a pre-charge circuit are provided on the input / output path of the battery, but a negative main switch is not provided.

[0096] The battery control unit can sequentially connect target batteries selected as balancing targets in parallel to the DC link according to priority.

[0097] Here, the battery control device can turn the precharge switch (SW_pc) of the first target battery (Nth-rank target battery) to the on (closed) state, and then turn the positive main switch (MSW_p) of the first target battery to the on (closed) state.

[0098] Thereafter, the battery control device can turn the precharge switch (SW_pc) of the second target battery (the N+1 target battery) to the on (closed) state, and then turn the positive main switch (MSW_p) of the second target battery to the on (closed) state.

[0099] For example, as illustrated in FIG. 5, if batteries #1, #3, and #5 among a plurality of batteries are selected as target batteries and the control priority is determined in the order of batteries #1, #3, and #5, the battery control device can turn the pre-charge switch (SW_pc) of battery #1 to an on (closed) state, then turn the positive main switch (MSW_p) of battery #1 to an on (closed) state, and then turn the pre-charge switch (SW_pc) of battery #1 to an off (open) state.

[0100] Thereafter, the battery control device can sequentially control the pre-charge switch (SW_pc) and the positive main switch (MSW_p) of each of batteries #3 and #5 as illustrated in FIG. 5, so that batteries #1, #3, and #5 are sequentially connected to the DC link.

[0101] If the switching time of each switch is 1 second, batteries #1, #3, and #5 can be connected to the DC link at points 2 seconds, 5 seconds, and 8 seconds after the initiation of balancing control (at the point when MSW_p is closed), respectively.

[0102]

[0103] FIG. 6 is a reference diagram illustrating an operating method of a battery system according to another embodiment of the present invention. Below, with reference to FIG. 6, another embodiment of the operating method of the battery system described in FIG. 5 will be described.

[0104] The battery control unit can sequentially connect target batteries selected as balancing targets in parallel to the DC link according to priority.

[0105] Here, the battery control device can turn on (close) the pre-charge switch (SW_pc) of the first target battery (Nth-ranked target battery), and then turn on (close) the positive main switch (MSW_p) of the first target battery. Thereafter, the battery control device can turn off (open) the pre-charge switch (SW_pc) of the first target battery.

[0106] Thereafter, the battery control device can turn on (close) the pre-charge switch (SW_pc) of the second target battery (the N+1 target battery) and then turn on (close) the positive main switch (MSW_p) of the second target battery. Thereafter, the battery control device can turn off (open) the pre-charge switch (SW_pc) of the second target battery.

[0107] 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.

[0108] For example, as illustrated in FIG. 6, if batteries #1, #3, and #5 among a plurality of batteries are selected as target batteries and the control priority is determined in the order of batteries #1, #3, and #5, the battery control device can turn the pre-charge switch (SW_pc) of battery #1 to an on (closed) state, then turn the positive main switch (MSW_p) of battery #1 to an on (closed) state, and then turn the pre-charge switch (SW_pc) of battery #1 to an off (open) state.

[0109] Thereafter, the battery control device can sequentially control the pre-charge switch (SW_pc) and the positive main switch (MSW_p) of battery #3, like 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 pre-charge switch (SW_pc) of battery #3 to the on (closed) state at the point in time when the pre-charge switch (SW_pc) of battery #1 switches to the off (open) state.

[0110] Likewise, the battery control device sequentially controls the pre-charge switch (SW_pc) and positive main switch (MSW_p) of battery #5 as in battery #1 and battery #3, but can switch the pre-charge switch (SW_pc) of battery #5 to the on (closed) state at the point in time when the pre-charge switch (SW_pc) of battery #3 switches to the off (open) state.

[0111] If the switching time of each switch is 1 second, batteries #1, #3, and #5 can be connected to the DC link at points 2 seconds, 4 seconds, and 6 seconds after the initiation of balancing control (at the point when MSW_p is closed), respectively.

[0112] If the switch included in the battery corresponds to a relay, power supply by the power supply device is unnecessary when switching the relay to the off (open) state. Accordingly, as illustrated in Fig. 6, if simultaneous control of the first target battery and the second target battery is performed in the control section for switching the pre-charge switch (SW_pc) to the off (open) state, the parallel connection time of the target batteries can be further shortened.

[0113]

[0114] FIG. 7 is a reference diagram illustrating an operating method of a battery system according to another embodiment of the present invention. Hereinafter, with reference to FIG. 7, an embodiment of an operating method of a battery system in which a positive main switch, a negative main switch, and a pre-charge circuit are provided on the input / output path of the battery will be described.

[0115] The battery control unit can sequentially connect target batteries selected as balancing targets in parallel to the DC link according to priority.

[0116] Here, the battery control device can turn on (close) the pre-charge switch (SW_pc) and the negative main switch (MSW_n) of the first target battery (the Nth-ranked target battery), and then turn on (close) the positive main switch (MSW_p) of the first target battery. Thereafter, the battery control device can turn off (open) the pre-charge switch (SW_pc) of the first target battery.

[0117] Thereafter, the battery control device can turn on (close) the pre-charge switch (SW_pc) and the negative main switch (MSW_n) of the second target battery (the N+1 target battery), and then turn on (close) the positive main switch (MSW_p) of the second target battery. Thereafter, the battery control device can turn off (open) the pre-charge switch (SW_pc) of the second target battery.

[0118] 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.

[0119] For example, as illustrated in FIG. 7, if batteries #1, #3, and #5 among a plurality of batteries are selected as target batteries and the control priority is determined in the order of batteries #1, #3, and #5, the battery control device can turn the pre-charge switch (SW_pc) and the negative main switch (MSW_n) of battery #1 to an on (closed) state, then turn the positive main switch (MSW_p) of battery #1 to an on (closed) state, and then turn the pre-charge switch (SW_pc) of battery #1 to an off (open) state.

[0120] 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 battery #3, like 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 pre-charge switch (SW_pc) and the negative main switch (MSW_n) of battery #3 to the on (closed) state at the point in time when the pre-charge switch (SW_pc) of battery #1 switches to the off (open) state.

[0121] Likewise, the battery control unit sequentially controls the pre-charge switch (SW_pc), positive main switch (MSW_p), and negative main switch (MSW_n) of battery #5 as in battery #1 and battery #3, but can switch the pre-charge switch (SW_pc) and negative main switch (MSW_n) of battery #5 to the on (closed) state at the point in time when the pre-charge switch (SW_pc) of battery #3 switches to the off (open) state.

[0122]

[0123] Figure 8 is a block diagram of a battery control device according to an embodiment of the present invention.

[0124] The battery control device (800) according to an embodiment of the present invention is positioned within a battery system including a plurality of batteries that can be connected in parallel on a DC link, and can be linked with battery management devices of each battery. For example, if the battery corresponds to a rack, the battery control device (800) may correspond to a BBMS, BSC, EMS, or PMS that are linked with a plurality of RBMSs.

[0125] The battery control device (800) may include at least one processor (810), a memory (820) that stores at least one command executed through the processor, and a transmission / reception device (830) that is connected to a network and performs communication.

[0126] The at least one command may include a command for selecting target batteries to be connected in parallel based on status information of the batteries; and a command for sequentially controlling a main switch arranged on an input / output path of each of the target batteries so that the target batteries are connected to the DC link at different times.

[0127] The command for selecting the target batteries may include a command for determining a battery that satisfies a predefined imbalance condition based on at least one of a voltage value and a SOC (State Of Charge) value as the target battery.

[0128] The command for sequentially controlling the main switch may include a command for determining a priority for controlling the target batteries based on one of the identifier, status value, and position of the battery.

[0129] The command for sequentially controlling the above main switches may include a command for switching the positive main switch of the first target battery to a closed state; and thereafter, a command for switching the positive main switch of the second target battery to a closed state.

[0130] The battery system may further include precharge circuits connected in parallel with the positive main switches of each of the plurality of batteries, each of which includes a precharge resistor and a precharge switch. Here, the command for sequentially controlling the main switches may include a command for switching the precharge switch of a first target battery to a closed state, and then switching the positive main switch of the first target battery to a closed state; and a command for switching the precharge switch of a second target battery to a closed state, and then switching the positive main switch of the second target battery to a closed state.

[0131] The command for sequentially controlling the main switches may include a command for 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 a command for switching the pre-charge switch of the second target battery to a closed state at the time when the pre-charge switch of the first target battery is switched to an open state.

[0132] The battery control device (800) may further include an input interface device (840), an output interface device (850), a storage device (860), etc. Each component included in the battery control device (800) may be connected by a bus (870) and communicate with each other.

[0133] Here, the processor (810) may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. The memory (or storage device) may be comprised of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory may be comprised of at least one of a read-only memory (ROM) and a random access memory (RAM).

[0134] The operations of the method according to an embodiment 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 any type of recording device that stores data readable by a computer system. Furthermore, a computer-readable recording medium can be distributed across network-connected computer systems, allowing the computer-readable program or code to be stored and executed in a distributed manner.

[0135] While some aspects of the present invention have been described in the context of a device, they may also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method may also be described as a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most significant method steps may be performed by such a device.

[0136] Although the present invention has been described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. Multiple batteries; and A battery control device is included that controls a main switch positioned on each input / output path of the plurality of batteries so that the batteries are connected in parallel to the DC link. The above battery control device, A battery system that selects target batteries to be connected in parallel based on status information of the batteries, controls the target batteries to be connected in parallel, and sequentially controls the main switch of each target battery so that the target batteries are connected to the DC link at different times.

2. In claim 1, The above battery control device, A battery system that determines a battery satisfying a predefined imbalance condition based on at least one of a voltage value and a SOC (State Of Charge) value as the target battery.

3. In claim 1, The above battery control device, A battery system that determines a priority for controlling target batteries based on one of the identifier, status value, and location of the battery.

4. In claim 1, The above battery control device, A battery system in which the positive main switch of the first target battery is turned to the closed state, and then the positive main switch of the second target battery is turned to the closed state.

5. In claim 1, Further comprising precharge circuits, each of which is connected in parallel with the positive main switch of each of the plurality of batteries and each of which includes a precharge resistor and a precharge switch, The above battery control device, After switching the precharge switch of the first target battery to the closed state, switching the positive main switch of the first target battery to the closed state, A battery system in which the precharge switch of the second target battery is turned to the closed state, and then the positive main switch of the second target battery is turned to the closed state.

6. In claim 5, The above battery control device, After switching the positive main switch of the first target battery to the closed state, switching the precharge switch of the first target battery to the open state, A battery system in which the pre-charge switch of the second target battery is switched to a closed state at the time when the pre-charge switch of the first target battery is switched to an open state.

7. In claim 5, The above battery control device, After switching the precharge switch and the negative main switch of the first target battery to the closed state, switching the positive main switch of the first target battery to the closed state, A battery system in which the precharge switch and the negative main switch of the second target battery are turned to the closed state, and then the positive main switch of the second target battery is turned to the closed state.

8. In claim 7, The above battery control device, After switching the positive main switch of the first target battery to the closed state, switching the precharge switch of the first target battery to the open state, A battery system in which the precharge switch and the negative main switch of the second target battery are switched to the closed state at the time when the precharge switch of the first target battery is switched to the open state.

9. In claim 1, The above battery, A battery system, comprising any one of a battery module, a battery pack, a battery rack, and a battery bank.

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

11. In claim 10, The step of selecting the above target batteries is: A method for operating a battery system, comprising the step of determining a battery satisfying a predefined imbalance condition based on at least one of a voltage value and a SOC (State Of Charge) value as the target battery.

12. In claim 10, The steps for sequentially controlling the above main switches are: A method of operating a battery system, comprising the step of determining a priority for controlling target batteries based on one of an identifier, a status value, and a location of the battery.

13. In claim 10, The steps for sequentially controlling the above main switches are: A step of switching the positive main switch of the first target battery to the closed state; and A method of operating a battery system, comprising the step of subsequently switching the positive main switch of the second target battery to a closed state.

14. In claim 10, The above battery system, Each of the plurality of batteries is connected in parallel with the positive main switch, and further includes precharge circuits each including a precharge resistor and a precharge switch. The steps for sequentially controlling the above main switches are: A step of switching the precharge 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 A method of operating a battery system, comprising the step of switching the precharge switch of the second target battery to a closed state and then switching the positive main switch of the second target battery to a closed state.

15. In claim 14, The steps for sequentially controlling the above main switches are: A step of switching the positive main switch of the first target battery to a closed state, and then switching the precharge switch of the first target battery to an open state; and A method of operating a battery system, comprising the step of switching the pre-charge switch of the second target battery to a closed state at a time when the pre-charge switch of the first target battery is switched to an open state.

16. A battery control device located within a battery system including a plurality of batteries that can be connected in parallel on a DC link, at least one processor; and A memory that stores at least one instruction to be executed through at least one processor, At least one of the above commands, A command for selecting target batteries to be connected in parallel based on the status information of the above batteries; and A battery control device comprising a command for sequentially controlling a main switch arranged on an input / output path of each of the target batteries so that the target batteries are connected to the DC link at different times.

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