Battery bank control device and method

Abstract

The present invention provides a battery bank control device for setting a power limit value for a battery bank in which a plurality of battery racks are connected in parallel, the battery bank control device including: a voltage measurement unit for measuring a voltage of each of the plurality of battery racks; a first power limit calculation unit for calculating a first power limit value for each of the battery racks according to an SOC calculated based on the voltage of each of the battery racks; a capacity ratio calculation unit for calculating a capacity ratio of each of the plurality of battery racks based on capacity information of the plurality of battery racks; a second power limit calculation unit for calculating a second power limit value using the capacity ratio of each of the battery racks and the first power limit value; and a battery bank power limit calculation unit for calculating a battery bank power limit value using the second power limit value of each of the battery racks.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0032430 filed on March 21, 2019, and all contents disclosed in the documents of this Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery bank control device and method. [Background technology]

[0003] Recently, research and development into secondary batteries has been actively conducted. Here, secondary batteries are batteries that can be charged and discharged, and include both conventional Ni / Cd batteries, Ni / MH batteries, and the latest lithium-ion batteries. Among secondary batteries, lithium-ion batteries have the advantage of having a much higher energy density than conventional Ni / Cd batteries, Ni / MH batteries, etc. Furthermore, lithium-ion batteries can be manufactured to be compact and lightweight, making them useful as power sources for mobile devices. Furthermore, lithium-ion batteries are gaining attention as a next-generation energy storage medium, with their range of use expanding to include power sources for electric vehicles.

[0004] In addition, secondary batteries are generally used as battery packs including battery modules in which a plurality of battery cells are connected in series and / or parallel, and the state and operation of the battery packs are managed and controlled by a battery management system.

[0005] Meanwhile, multiple battery modules are connected in series or parallel to form a battery rack, and multiple battery racks are connected in parallel to form a battery bank. Such battery banks can be used as ESSs (Energy Storage Systems). Among these ESSs, grid-oriented ESSs often have long performance guarantee periods due to their business characteristics. Therefore, there are cases where one battery rack within an ESS breaks down or a battery rack needs to be added due to insufficient battery capacity. When a battery rack is added, there may be differences in the versions between the existing battery rack and the newly added battery rack due to the time gap, resulting in imbalances in output current distribution due to the difference in capacity. In addition, the battery bank power limit value calculated using conventional battery bank power limit logic can cause overcharging issues due to imbalances in output current distribution between battery racks. Summary of the Invention [Problem to be solved by the invention]

[0006] The purpose of the present invention is to efficiently improve maximum output by eliminating the imbalance in output current distribution between battery racks that occurs when a new battery rack is added to an ESS or when some of the existing battery racks deteriorate. [Means for solving the problem]

[0007] A battery bank control device according to one embodiment of the present invention is a device for setting a power limit value of a battery bank in which a plurality of battery racks are connected in parallel, and includes a voltage measurement unit for measuring a voltage of each of the plurality of battery racks; a first power limit calculation unit for calculating a first power limit value for each of the battery racks according to an SOC calculated based on the voltage of each of the battery racks; a capacity ratio calculation unit for calculating a capacity ratio of each of the plurality of battery racks based on capacity information of the plurality of battery racks; a second power limit calculation unit for calculating a second power limit value using the capacity ratio of each of the battery racks and the first power limit value; and a battery bank power limit calculation unit for calculating a battery bank power limit value using the second power limit value of each of the battery racks.

[0008] The battery bank control device according to an embodiment of the present invention further includes an SOC calculation unit that calculates an SOC of each battery rack based on a voltage of each battery rack.

[0009] In the battery bank control device according to an embodiment of the present invention, the SOC of each battery rack is a value that changes in real time, and therefore the battery bank power limit value is also a value that changes in real time.

[0010] A battery bank control device according to one embodiment of the present invention further includes a temperature measurement unit that measures the temperature of each of the plurality of battery racks, and uses the temperature of each of the battery racks when calculating the SOC of each of the battery racks.

[0011] In a battery bank control device according to one embodiment of the present invention, the second power limit calculation unit calculates the second power limit value by dividing the first power limit value of each battery rack by the capacity ratio for that battery rack.

[0012] In a battery bank control device according to an embodiment of the present invention, the battery bank power limit calculation unit calculates the smallest value among the second power limit values of the battery racks as the battery bank power limit value.

[0013] A battery bank control method according to one embodiment of the present invention is a method for setting a power limit for a battery bank in which a plurality of battery racks are connected in parallel, and includes the steps of measuring a voltage of each of the plurality of battery racks; calculating a first power limit value for each of the battery racks according to an SOC calculated based on the voltage of each of the battery racks; calculating a capacity ratio of each of the battery racks based on capacity information of the plurality of battery racks; calculating a second power limit value using the capacity ratio of each of the battery racks and the first power limit value; and calculating a battery bank power limit value using the second power limit value of each of the battery racks.

[0014] In the battery bank control method according to an embodiment of the present invention, the SOC of each battery rack is a value that changes in real time, and accordingly, the battery bank power limit value is also a value that changes in real time.

[0015] The battery bank control method according to an embodiment of the present invention further includes measuring a temperature of each battery rack, and using the temperature of each battery rack when calculating the SOC of each battery rack.

[0016] In the step of calculating the second power limit value of the battery bank control method according to an embodiment of the present invention, the first power limit value of each battery rack is divided by the capacity ratio for the corresponding battery rack.

[0017] In the step of calculating the battery bank power limit value of the battery bank control method according to an embodiment of the present invention, the smallest value among the second power limit values of the battery racks is calculated as the bank power limit value. [Effects of the Invention]

[0018] The present invention has the advantage that the power limit value of the battery bank can be set using the capacity ratio between the battery racks, thereby enabling full output use. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram illustrating a battery bank power limit calculation device according to an embodiment of the present invention. [Figure 2] FIG. 10 is a diagram illustrating a battery bank power limit calculation device according to another embodiment of the present invention. [Figure 3a] FIG. 1 illustrates exemplary capacity and energy values of a battery cell. [Figure 3b] 10 is a graph illustrating a first power limit value calculated by a bank power limit calculation unit according to another embodiment of the present invention. [Figure 4] FIG. 10 is a diagram illustrating a conventional method for calculating a bank power limit based on the connection state of a battery rack. [Figure 5] FIG. 10 is a diagram showing a bank power limit graph according to SOC calculated using existing bank power limit calculation logic (existing logic) and a bank power limit graph according to SOC calculated using bank power limit calculation logic according to the present invention (new logic). [Figure 6]3 is a flowchart of a method for calculating a battery bank power limit according to an embodiment of the present invention. [Figure 7] 10 is a flowchart of a battery bank power limit calculation method according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, various embodiments of the present invention will be described with reference to the drawings. However, it should be understood that this is not intended to limit the present invention to the specific embodiments, but rather includes various modifications, equivalents, and / or alternatives of the embodiments of the present invention. In describing the drawings, similar reference numerals may be used for similar components.

[0021] The terms used in this document are used only to describe specific embodiments and are not intended to limit the scope of other embodiments. A singular expression may include a plural expression unless the context clearly dictates otherwise. All terms used herein, including technical and scientific terms, may have the same meaning as commonly understood by a person of ordinary skill in the art of the present invention. Terms defined in commonly used dictionaries may be interpreted as having the same or similar meaning as the meaning they have in the context of the relevant art, and unless explicitly defined in this document, they should not be interpreted in an ideal or overly formal sense. In some cases, terms defined in this document may not be interpreted to exclude embodiments of the present invention.

[0022] Furthermore, when describing components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are merely used to distinguish the component from other components, and do not limit the essence, order, or procedure of the components. When a component is described as being "coupled," "coupled," or "connected" to another component, it should be understood that the component may be directly coupled or connected to the other component, but that other components may also be "coupled," "coupled," or "connected" between each component.

[0023] 1 is a diagram showing a battery bank power limit calculation device 10 according to one embodiment of the present invention. The battery bank power limit calculation device 10 is also called a battery bank control device.

[0024] The battery bank power limit calculation device 10 includes a voltage measurement unit 100, a temperature measurement unit 102, an SOC calculation unit 104, a first power limit calculation unit 106, a capacity ratio calculation unit 108, a second power limit calculation unit 110, a battery bank power limit calculation unit 112, and a transmission unit 114.

[0025] The battery bank is formed by connecting multiple battery racks 40 to 44 in parallel. The battery racks may be of the same type or different types. Even if the battery racks are of the same type, they may have different lifespans.

[0026] The voltage measurement unit 100 measures the voltage of each battery rack 40 to 44 in real time. The voltage of each battery rack measured by the voltage measurement unit 100 is transmitted to the SOC calculation unit 104. Although the voltage measurement unit 100 is included in one embodiment of the present invention, a current measurement unit may be included instead of the voltage measurement unit 100.

[0027] If a current measurement unit is included, the current value of each battery rack measured by the current measurement unit can be transmitted to the SOC calculation unit 104.

[0028] The temperature measurement unit 102 measures the temperature of each of the battery racks in real time. The temperature measurement unit 102 may be, for example, a thermistor. The temperature measurement unit 102 transmits the measured temperature value of each battery rack to the SOC calculation unit 104. Since the battery capacity is also affected by the temperature, the real-time measured temperature value of the battery can also be reflected when calculating the remaining capacity of the battery.

[0029] The SOC calculation unit 104 receives the voltage values of the battery racks 40 to 44 measured by the voltage measurement unit 100. The SOC calculation unit 104 also receives the temperature values of the battery racks 40 to 44 measured by the temperature measurement unit 102.

[0030] The SOC calculation unit 104 calculates the SOC value of each battery rack 40 to 44 using the received voltage value of each battery rack 40 to 44. At this time, since the battery voltage is greatly affected by the battery temperature, the SOC can be calculated by taking the battery temperature value into consideration when calculating the SOC using the battery voltage.

[0031] Also, a current measuring unit may be included instead of the voltage measuring unit 100. In this case, the current measuring unit can transmit the current value of each battery rack 40-44 to the SOC calculating unit 104. Next, the SOC calculating unit 104, which receives the current value of each battery rack 40-44 from the current measuring unit, can integrate the current value of each battery rack 40-44 over a certain period of time to calculate the SOC value for each battery rack 40-44.

[0032] Although the method of calculating the SOC by measuring the voltage or current of the battery rack has been described above, other methods capable of calculating the SOC, such as chemical methods or pressure measurement methods, can be substituted.

[0033] The first power limit calculation unit 106 receives the SOC value of each battery rack 40-44 from the SOC calculation unit 104. The first power limit calculation unit 106 calculates a power limit value according to the SOC value of each battery rack 40-44. The first power limit calculation unit 106 calculates a first power limit value according to the calculated SOC value of each battery rack 40-44. The first power limit value according to the SOC value corresponds to the minimum value of the charging power and discharging power according to the SOC of the corresponding battery rack. Here, the charging / discharging power limit value may be suggested according to the SOC. For example, when the SOC is 50%, the charging power limit may be 100 kW and the discharging power limit may be 100 kW; when the SOC is 100%, the charging power limit may be 0 kW and the discharging power limit may be 100 kW; and when the SOC is 0%, the charging power limit may be 100 kW and the discharging power limit may be 0 kW.

[0034] The first power limit calculation unit 106 transmits the calculated first power limit values of the respective battery racks 40 to 44 to the second power limit calculation unit 110.

[0035] The capacity ratio calculation unit 108 calculates the ratio of the capacity of a battery rack to the total capacity of the plurality of battery racks. That is, the capacity ratio of the battery rack is calculated based on the capacity information of each of the plurality of battery racks. The capacity ratio calculation unit 108 calculates the ratio of the capacity of each of the plurality of battery racks to the total capacity of the battery racks. For example, information on the state of health (SOH) and capacity required for the capacity ratio calculation unit 108 to calculate the capacity ratio of the battery racks may be stored in a battery management system (BMS) (not shown). The capacity ratio calculation unit 108 transmits the calculated capacity ratio of each battery rack to the second power limit calculation unit 110.

[0036] The second power limit calculation unit 110 receives the first power limit values of the respective battery racks 40 to 44 from the first power limit calculation unit 106. The second power limit calculation unit 110 also receives the capacity ratios of the respective battery racks 40 to 44 from the capacity ratio calculation unit 108.

[0037] The second power limit calculation unit 110 divides the first power limit value of each battery rack by the capacity ratio of that battery rack. That is, the second power limit calculation unit 110 calculates the value obtained by dividing the first power limit value of each battery rack by the capacity ratio of that battery rack as the second power limit value of that battery rack.

[0038] The second power limit calculation unit 110 transmits the calculated second power limit value of each battery rack to the bank power limit calculation unit 112.

[0039] The bank power limit calculation unit 112 receives the second power limit values of the respective battery racks 40 to 44 from the second power limit calculation unit 110.

[0040] The bank power limit calculation unit 112 calculates the smallest value among the received second power limit values as the bank power limit value.

[0041] When the bank power limit calculation unit 112 transmits the calculated bank power limit value to the transmission unit 114, the transmission unit 114 transmits the bank power limit value to the PCS (power converter) control unit 30.

[0042] The PCS control unit 30 receives the bank power limit value from the transmission unit 114 and controls the PCS 20 based on the received bank power limit value.

[0043] FIG. 2 is a diagram showing a battery bank power limit calculation device 11 according to another embodiment of the present invention.

[0044] A battery bank power limit calculation device 11 according to another embodiment of the present invention includes a receiving unit 200, a first power limit calculation unit 206, a capacity ratio calculation unit 208, a second power limit calculation unit 210, a bank power limit calculation unit 212, and a transmitting unit 214.

[0045] Each battery rack is connected to a battery management system that controls or monitors the battery rack. Each battery management system 50-54 measures the voltage or current of each battery cell in the battery rack to which the battery management system is connected and calculates a power limit based on the SOC of each battery cell. Each battery management system 50-54 also transmits the power limit value based on the real-time SOC of the battery cells included in the battery rack to the battery bank power limit calculation device 11.

[0046] The receiving unit 200 receives, from each of the battery management systems 50 to 54, a power limit value based on the real-time SOC of each of the battery cells in the battery rack to which the corresponding battery management system is connected. The receiving unit 200 transmits the received power limit value based on the real-time SOC of the battery cells in each of the battery racks to the first power limit calculating unit 206.

[0047] The first power limit calculation unit 206 receives the power limit value based on the real-time SOC of each of the multiple battery cells in each battery rack from the receiving unit 200. The first power limit calculation unit 206 calculates the smallest power limit value of the battery cells in the battery rack as the power limit value of the battery rack using the received power limit values based on the real-time SOC of each of the multiple battery cells in the battery rack. The first power limit calculation unit 206 calculates the power limit of the battery rack as the first power limit of the battery rack.

[0048] The first power limit calculation unit 206 transmits the first power limit value calculated for each battery rack to the second power limit calculation unit 210.

[0049] The capacity ratio calculation unit 208 calculates the ratio of the capacity of a battery rack to the total capacity of the plurality of battery racks. The capacity ratio calculation unit 208 calculates the capacity ratio of each battery rack to the total capacity of the battery racks. For example, information related to the SOH and capacity required for the capacity ratio calculation unit 208 to calculate the capacity ratio of the battery racks may be stored in each of the battery management systems 50 to 54. The capacity ratio calculation unit 208 transmits the calculated capacity ratio of each battery rack to the second power limit calculation unit 210.

[0050] The second power limit calculation unit 210 receives the first power limit values of the respective battery racks 40 to 44 from the first power limit calculation unit 206. In addition, the second power limit calculation unit 210 receives the capacity ratios of the respective battery racks 40 to 44 from the capacity ratio calculation unit 208.

[0051] The second power limit calculation unit 210 divides the first power limit of each battery rack by the capacity ratio of that battery rack. The second power limit calculation unit 210 calculates the value obtained by dividing the first power limit of each battery rack by the capacity ratio of that battery rack as the second power limit value of that battery rack.

[0052] The second power limit calculation unit 210 transmits the calculated second power limit value of each battery rack to the bank power limit calculation unit 212.

[0053] The bank power limit calculation unit 212 receives the second power limit values of the respective battery racks 40 to 44 from the second power limit calculation unit 210.

[0054] The bank power limit calculation unit 212 calculates the smallest value among the received second power limit values as the bank power limit value.

[0055] The bank power limit calculation unit 212 transmits the calculated bank power limit value to the transmission unit 214, and the transmission unit 214 transmits the bank power limit value to the PCS control unit 30.

[0056] The PCS control unit 30 receives the bank power limit value from the transmission unit 214 and controls the PCS 20 based on the received bank power limit value.

[0057] FIG. 3a is a diagram illustrating exemplary capacity and energy values of a battery cell.

[0058] FIG. 3b is a graph for deriving a first power limit value calculated by the bank power limit calculation unit 212 according to another embodiment of the present invention.

[0059] As shown in the table in Figure 3a, each battery cell has different inherent physical properties, which results in different capacities and energy.

[0060] As a result, the power limit value changes depending on the SOC for each battery cell, as shown in the graph in Figure 3b. For example, the power limit of a battery rack including battery cells JP1 and JP3 is a graph in which the minimum value of the power limits of each battery cell is indicated by a dotted line. The first power limit of the battery bank power limit calculation device 11 according to another embodiment of the present invention shown in Figure 2 can be calculated by calculating the power limit value corresponding to the dotted line in the graph in Figure 3b.

[0061] FIG. 4 is a diagram showing a conventional method for calculating the bank power limit based on the connection state of the battery rack.

[0062] 4 shows a conventional method for calculating the bank power limit, in which the power limit of each battery rack is, for example, 225 kW, the input power of each battery rack is 200 kW, and power within the power limit of each battery rack is applied, with all battery racks in a normal state. Therefore, since all battery racks are connected to the battery bank, the bank power limit is calculated by multiplying the power limit value of the battery rack by the number of battery racks.

[0063] Referring to FIG. 5, there is shown a bank power limit graph according to SOC calculated using the existing bank power limit calculation logic (existing logic) and a bank power limit graph according to SOC calculated using the bank power limit calculation logic (new logic) according to the present invention.

[0064] In this case, the bank power limit based on SOC calculated using the existing bank power limit calculation logic (logic that multiplies the same power limit value by the number of battery racks without considering capacity) was calculated without considering cases where the types or capacities of the battery racks were different, which resulted in overcharging issues within certain SOC ranges.

[0065] Meanwhile, the bank power limit according to the SOC calculated using the bank power limit calculation logic of the present invention is calculated and set taking into consideration the type and capacity of each battery rack, so that the output distribution is balanced, and the maximum output can be achieved while eliminating the problem of overcharging.

[0066] FIG. 6 is a flowchart of a method for calculating a battery bank power limit according to one embodiment of the present invention.

[0067] The battery bank is formed by connecting multiple battery racks 40 to 44 in parallel. The battery racks may be of the same type or different types. Even if the battery racks are of the same type, they may have different lifespans.

[0068] The voltage measurement unit 100 measures the voltage of each battery rack 40-44 in real time (S600). The voltage of each battery rack measured by the voltage measurement unit 100 is transmitted to the SOC calculation unit 104. Although the voltage measurement unit 100 is included in one embodiment of the present invention, a current measurement unit may be included instead of the voltage measurement unit 100.

[0069] The SOC calculation unit 104 receives the voltage values of each of the battery racks 40-44 measured by the voltage measurement unit 100. The SOC calculation unit 104 calculates the SOC value of each of the battery racks 40-44 using the received voltage values of each of the battery racks 40-44 (S602). At this time, since the battery voltage is greatly affected by the battery temperature, the battery temperature value can also be taken into consideration when calculating the SOC using the battery voltage.

[0070] The first power limit calculation unit 106 receives the SOC values of each of the battery racks 40-44 from the SOC calculation unit 104. The first power limit calculation unit 106 calculates a power limit value based on the SOC value of each of the battery racks 40-44. The first power limit calculation unit 106 calculates a first power limit value based on the calculated SOC value of each of the battery racks 40-44 (S604). The first power limit calculation unit 106 transmits the calculated first power limit value of each of the battery racks 40-44 to the second power limit calculation unit 110.

[0071] The capacity ratio calculation unit 108 calculates the ratio of the capacity of a battery rack to the total capacity of the plurality of battery racks (S606). The capacity ratio calculation unit 108 calculates the ratio of the capacity of the battery rack to the total capacity of each of the plurality of battery racks. The capacity ratio calculation unit 108 transmits the calculated capacity ratio of each battery rack to the second power limit calculation unit 110.

[0072] The second power limit calculation unit 110 receives the first power limit values of the respective battery racks 40 to 44 from the first power limit calculation unit 106. The second power limit calculation unit 110 also receives the capacity ratios of the respective battery racks 40 to 44 from the capacity ratio calculation unit 108.

[0073] The second power limit calculation unit 110 calculates a second power limit value using the first power limit value and the capacity ratio of the corresponding battery rack (S608). Specifically, the second power limit calculation unit 110 divides the first power limit of each battery rack by the capacity ratio of the corresponding battery rack. That is, the second power limit calculation unit 110 calculates the value obtained by dividing the first power limit of each battery rack by the capacity ratio of the corresponding battery rack as the second power limit value of each battery rack.

[0074] The second power limit calculation unit 110 transmits the calculated second power limit value of each battery rack to the bank power limit calculation unit 112.

[0075] The bank power limit calculation unit 112 receives the second power limit values of the respective battery racks 40 to 44 from the second power limit calculation unit 110.

[0076] The bank power limit calculation unit 112 calculates a battery bank power limit value using the second power limit values (S610). Specifically, the bank power limit calculation unit 112 calculates the smallest value among the received second power limit values as the bank power limit value.

[0077] When the bank power limit calculation unit 112 transmits the calculated bank power limit value to the transmission unit 114, the transmission unit 114 transmits the bank power limit value to the PCS (power converter) control unit 30.

[0078] The PCS control unit 30 receives the bank power limit value from the transmission unit 114 and controls the PCS based on the received bank power limit value.

[0079] FIG. 7 is a flowchart of a battery bank power limit calculation method according to another embodiment of the present invention.

[0080] Each battery rack is connected to a battery management system that controls or monitors the battery rack. Each battery management system 50-54 measures the voltage or current of each battery cell in the battery rack to which the battery management system is connected, and calculates a power limit based on the SOC of each battery cell. Each battery management system 50-54 also transmits a power limit value based on the real-time SOC of the battery cells included in the battery rack to the battery bank power limit calculation device 11.

[0081] The receiving unit 200 receives, from each of the battery management systems 50 to 54, a power limit value based on the real-time SOC of the battery cells in the battery rack to which the corresponding battery management system is connected (S700). The receiving unit 200 transmits the received power limit value based on the real-time SOC of the battery cells in each of the battery racks to the first power limit calculating unit 206.

[0082] The first power limit calculation unit 206 calculates the smallest power limit value among the power limit values of the battery cells in each battery rack using the received power limit values based on the real-time SOC of the battery cells in the battery rack as the power limit value of the battery rack (S702). The first power limit calculation unit 206 transmits the first power limit value calculated for each battery rack to the second power limit calculation unit 210.

[0083] The capacity ratio calculation unit 208 calculates the ratio of the capacity of a battery rack to the total capacity of the plurality of battery racks. The capacity ratio calculation unit 208 calculates the ratio of the capacity of a battery rack to the total capacity of each of the plurality of battery racks. The capacity ratio calculation unit 208 transmits the calculated capacity ratio of each battery rack to the second power limit calculation unit 210.

[0084] The second power limit calculation unit 210 receives the first power limit values of the respective battery racks 40 to 44 from the first power limit calculation unit 206. In addition, the second power limit calculation unit 210 receives the capacity ratios of the respective battery racks 40 to 44 from the capacity ratio calculation unit 208.

[0085] The second power limit calculation unit 210 calculates the second power limit value using the first power limit value of each battery rack and the capacity ratio of the battery rack (S706).

[0086] Specifically, the second power limit calculation unit 210 divides the first power limit of each battery rack by the capacity ratio of the battery rack. The second power limit calculation unit 210 calculates the value obtained by dividing the first power limit of each battery rack by the capacity ratio of the battery rack as the second power limit value of each battery rack. The second power limit calculation unit 210 transmits the calculated second power limit value of each battery rack to the bank power limit calculation unit 212.

[0087] The bank power limit calculation unit 212 calculates a battery bank power limit value using the second power limit values (S708). Specifically, the bank power limit calculation unit 212 calculates the smallest value among the received second power limit values as the bank power limit value.

[0088] The bank power limit calculation unit 212 transmits the calculated bank power limit value to the transmission unit 214, and the transmission unit 214 transmits the bank power limit value to the PCS control unit 30.

[0089] The PCS control unit 30 receives the bank power limit value from the transmission unit 214 and controls the PCS based on the received bank power limit value.

[0090] References herein to "one embodiment" of the present principles, as well as various variations of such phrases, mean that a particular feature, structure, characteristic, etc., associated with this embodiment is included in at least one embodiment of the present principles. Thus, the appearances of the phrase "in one embodiment" and any other variations disclosed throughout this specification do not necessarily all refer to the same embodiment.

[0091] All embodiments and conditional examples disclosed throughout this specification are intended to help those skilled in the art to understand the principles and concepts of the present invention. Those skilled in the art will understand that the present invention can be embodied in modified forms without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative rather than a restrictive perspective. The scope of the present invention is defined by the claims, not the foregoing description, and all differences within the scope of the claims should be construed as being within the scope of the present invention. [Explanation of symbols]

[0092] JP1 Battery Cell JP3 battery cell 10 Battery bank power limit calculation device 11 Battery bank power limit calculation device 20 PCS 30 PCS (power converter) control unit, PCS control unit 40 Battery Rack 41 Battery Rack 42 Battery Rack 43 Battery Rack 44 Battery Rack 50 Battery Management System 51 Battery Management System 52 Battery Management System 53 Battery Management System 54 Battery Management System 100 Voltage measurement section 102 Temperature measurement section 104 SOC calculation section 106 First power limit calculation unit 108 Capacity ratio calculation section 110 Second power limit calculation unit 112 Bank power limit calculation unit, battery bank power limit calculation unit 114 Transmission Unit 200 Receiver 206 First power limit calculation unit 208 Capacity ratio calculation section 210 Second power limit calculation unit 212 Bank power limit calculation section 214 Transmission Unit

Claims

1. A device for setting a power limit value of a battery bank in which a plurality of battery racks are connected in parallel, comprising: a voltage measuring unit that measures the voltage of each of the plurality of battery racks; a first power limit calculation unit that calculates a first power limit value for each of the battery racks according to a current SOC calculated based on a voltage of each of the battery racks; a capacity ratio calculation unit that calculates a capacity ratio, which is a ratio of a capacity of each battery rack to a total capacity of the plurality of battery racks, based on the SOH and capacity of the plurality of battery racks; a second power limit calculation unit that calculates a second power limit value using the capacity ratio of each of the battery racks and the first power limit value; and a battery bank power limit calculation unit that calculates a battery bank power limit value using the second power limit value of each battery rack; Including, The second power limit calculation unit Calculating the second power limit value by dividing the first power limit value of each battery rack by the capacity ratio for that battery rack; The battery bank power limit calculation unit a battery bank control device that calculates the smallest value among the second power limit values of the battery racks as the battery bank power limit value;

2. The battery bank control device according to claim 1 , further comprising an SOC calculation unit that calculates an SOC of each battery rack based on the voltage of each battery rack.

3. 3. The battery bank control device according to claim 1, wherein the SOC of each battery rack is a value that changes in real time, and accordingly, the battery bank power limit value is also a value that changes in real time.

4. Further comprising a temperature measuring unit for measuring the temperature of each of the plurality of battery racks; The battery bank control device according to any one of claims 1 to 3, wherein the temperature of each battery rack is used when calculating the SOC of each battery rack.

5. A method for setting a power limit for a battery bank in which multiple battery racks are connected in parallel, comprising: measuring a voltage of each battery rack of the plurality of battery racks; calculating a first power limit value for each of the battery racks according to a current SOC calculated based on a voltage of the battery rack; calculating a capacity ratio, which is a ratio of the capacity of each battery rack to the total capacity of the plurality of battery racks, based on the SOH and capacity of the plurality of battery racks; calculating a second power limit value using the capacity ratio of each battery rack and the first power limit value; and calculating a battery bank power limit value using the second power limit value of each battery rack; Including, In the step of calculating the second power limit value, Calculating the second power limit value by dividing the first power limit value of each battery rack by the capacity ratio for that battery rack; In the step of calculating the battery bank power limit value, The battery bank control method further comprises calculating the smallest value among the second power limit values of the battery racks as a bank power limit value.

6. 6. The battery bank control method according to claim 5, wherein the SOC of each battery rack is a value that changes in real time, and accordingly, the battery bank power limit value is also a value that changes in real time.

7. measuring the temperature of each battery rack; 7. The battery bank control method of claim 5, wherein the temperature of each battery rack is used when calculating the SOC of each battery rack.

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