Battery management systems and battery racks for wireless charging

Abstract

The present invention provides a battery management system for wireless charging. The battery management system includes a communication unit and a controller. The communication unit receives information about a first state of charge (SOC) of a first battery module, a second SOC of a second battery module, and a third SOC of a third battery module. The controller controls a first wireless charging between the first and second battery modules and a second wireless charging between the second and third battery modules to balance the first, second, and third SOCs. The first wireless charging wirelessly transmits power from one of the first and second battery modules to the other. The second wireless charging wirelessly transmits power from one of the second and third battery modules to the other.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2020-0072623, filed on June 15, 2020, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to a battery management system, and more particularly, to a battery management system for managing wireless charging between battery modules and a battery rack including the battery management system. Background Art

[0004] Recently, research and development on secondary batteries have been actively carried out. Here, secondary batteries are batteries that can be charged and discharged, and include all conventional Ni / Cd batteries, Ni / MH batteries and the recent lithium-ion batteries. Among secondary batteries, the advantage of lithium-ion batteries is that their energy density is much higher than that of conventional Ni / Cd batteries and Ni / MH batteries. Lithium-ion batteries can be made small and light and are used as power sources for mobile devices. In particular, lithium-ion batteries can be used as power sources for electric vehicles and are therefore attracting attention as the next generation energy storage medium.

[0005] Secondary batteries are generally used as battery module units in which a plurality of battery cells are connected in series and / or in parallel. Due to characteristic differences and temperature differences between cells, charge imbalance occurs between the battery cells included in one battery rack (or battery pack).

[0006] Because unbalanced charging can degrade battery rack performance, cell balancing technology is used to address this. Most currently used cell balancing technologies are wired. Consequently, as the number of cells increases, the connections between wires and switches become increasingly complex, increasing manufacturing time and costs. Summary of the Invention

[0007] Technical issues

[0008] The present invention aims to solve the above technical problems, and an object of the present invention is to provide a battery management system for solving charging imbalance between battery modules by controlling wireless charging between battery modules.

[0009] Technical Solution

[0010] A battery management system according to an embodiment of the present invention may include a communication unit and a controller. The communication unit may receive information about a first state of charge (SOC) of a first battery module, a second SOC of a second battery module, and a third SOC of a third battery module. The controller may control a first wireless charging between the first battery module and the second battery module and a second wireless charging between the second battery module and the third battery module to balance the first SOC, the second SOC, and the third SOC. The first wireless charging may be wirelessly transmitting power from one of the first battery module and the second battery module to the other battery module. The second wireless charging may be wirelessly transmitting power from one of the second battery module and the third battery module to the other battery module.

[0011] A battery rack according to an embodiment of the present invention may include multiple battery modules and a battery management system. The battery management system may control wireless charging between adjacent battery modules so that the sum of the absolute differences in the SOCs of adjacent battery modules among the multiple battery modules is reduced, and control a first battery module so that power is output from the first battery module to the second battery module among the adjacent battery modules. The SOC of the first battery module may be greater than the SOC of the second battery module. The first battery module may include a first antenna on one surface facing the second battery module, and power may be transmitted via the first antenna.

[0012] [Effects of the Invention]

[0013] A battery rack according to an embodiment of the present invention can charge battery modules through wireless power transmission between the battery modules. A battery management system according to an embodiment of the present invention can control wireless charging of the battery modules to reduce the difference in SOC values ​​between adjacent battery modules based on the SOC values ​​of the battery modules. Therefore, cell balancing between the battery modules can be performed through wireless charging between the battery modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a block diagram illustrating a configuration of a battery rack according to an embodiment of the present invention.

[0015] Figure 2a It shows Figure 1 A perspective view of the structure of the battery module 2.

[0016] Figure 2b yes Figure 1 A side view of the structure of the battery module 2.

[0017] Figure 3 is a diagram showing a method according to an embodiment of the present invention. Figure 1 A block diagram of the configuration of the battery module 2.

[0018] Figure 4 is a diagram showing a method according to an embodiment of the present invention. Figure 1 Conceptual diagram of wireless charging between battery modules 1 to n.

[0019] Figure 5a It is shown that according to the embodiment Figure 1 The RBMS 150 calculates the charging power e 12 to e 34 Picture.

[0020] Figure 5b It shows that according to Figure 5a The charging power e calculated in 12 to e 34 A graph of charging power moving between battery modules 1 to 4.

[0021] Figure 6 It shows Figure 5b Flowchart of wireless charging operation between battery modules 1 to 4.

[0022] Figure 7 It is used to explain another embodiment Figure 1 Conceptual diagram of wireless charging between battery modules 1 to 4.

[0023] Figure 8 It is shown according to the reference Figure 7 A diagram depicting the method for moving charging power between battery modules 1 to 4.

[0024] Figure 9 is a diagram showing a hardware configuration of a BMS according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this document, the same reference numerals are used for the same components in the drawings, and repeated description of the same components is omitted.

[0026] For the various embodiments of the present invention disclosed herein, specific structural or functional descriptions have been illustrated for the purpose of describing only the embodiments of the present invention, and the various embodiments of the present invention may be implemented in various forms and should not be construed as limited to the embodiments described herein.

[0027] Expressions such as "first," "second," "first," or "second" used in various embodiments may modify various elements, regardless of their order and / or importance, and do not limit the corresponding elements. For example, a first component may be referred to as a second component, and similarly, a second component may be renamed and referred to as a first component without departing from the scope of the present invention.

[0028] The terms used herein are only used to describe specific embodiments and are not intended to limit the scope of other embodiments.Unless otherwise specified, terms in the singular may include plural forms.

[0029] All terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by those skilled in the art. Terms defined in commonly used dictionaries may be interpreted as having the same or similar meaning as in the context of the prior art and, unless expressly defined herein, are not to be interpreted as having an ideal or overly formal meaning. In some cases, even terms defined herein cannot be interpreted as excluding embodiments of the present invention.

[0030] Figure 1 is a block diagram illustrating a configuration of a battery rack according to an exemplary embodiment of the present invention.

[0031] The battery rack 100 may include a rack battery management system (RBMS) 150 and battery modules 1 to n. The battery modules 1 to n may each include battery cells (not shown) connected in series or in parallel, module battery management systems (MBMS) 10 to n0 for managing the battery cells, and one or more antennas. The battery rack 100 of the present invention is not limited to Figure 1 The location and quantity of components shown.

[0032] In this specification, those skilled in the art may refer to battery rack 100 as a battery pack. Battery rack 100 is a battery device primarily used in energy storage systems (ESS), while a battery pack is a battery device primarily used in vehicles. A battery pack can provide substantially the same operations as battery rack 100. RBMS 150 and MBMSs 10 through n0 may correspond to the master and slave BMSs of a battery pack.

[0033] MBMS 10 to n0 can monitor the battery cells included in each of the battery modules 1 to n. Figure 1 The description will focus on the configuration and operation of the battery module 1 and the MBMS 10. The remaining battery modules 2 to n and the remaining MBMSs 20 to n0 provide substantially the same operation as the battery module 1 and the MBMS 10.

[0034] The battery module 1 may include battery cells connected in series or in parallel, the MBMS 10, and an antenna. Figure 1 , the antenna is represented by a shaded rectangle. The antenna of the battery module 1 may be located on one surface facing an adjacent battery module 2 among the battery modules 2 to n arranged in a row. Figure 1 The first battery module 1 and the last battery module n among the battery modules 1 to n arranged in a line are shown as including one antenna, but the present invention is not limited thereto. The battery modules 1 and n may also include two antennas like other battery modules.

[0035] MBMS 10 can monitor and manage the battery cells of battery module 1. MBMS 10 can measure the voltage of the battery cells. MBMS 10 can obtain information about the state of charge (SOC) of the battery cells based on the voltage of the battery cells. MBMS 10 can calculate the SOC of battery module 1 by summing all the SOCs of the battery cells. MBMS 10 can transmit information about the SOC of battery module 1 and / or information about the SOC of each battery cell to RBMS 150.

[0036] The RBMS 150 can communicate with the MBMS 10 to transmit / receive information. The RBMS 150 can transmit and receive information through the MBMS 10 and a controller area network (CAN) communication, or can transmit and receive information through wireless communication such as Zigbee, Wifi, and Bluetooth Low Energy (BLE).

[0037] The RBMS 150 may receive information about the SOC of the battery module 1 from the MBMS 10. However, the present invention is not limited thereto, and the RBMS 150 may receive information about the SOC of each of the battery cells of the battery module 1 from the MBMS 10. The RBMS 150 may calculate the SOC of the battery module 1 based on the information about the SOC of each of the battery cells of the battery module 1.

[0038] As mentioned above, the remaining MBMSs 20 to n0 provide substantially the same operations as the MBMS 10. That is, the RBMS 150 can receive information about the SOC of each of the battery modules 1 to n from the MBMSs 10 to n0. The RBMS 150 can control wireless charging between the battery modules 1 to n based on the information about the SOC of each of the battery modules 1 to n.

[0039] The RBMS 150 may determine the direction and size of wireless charging between the battery modules 1 to n so that the sum of absolute values ​​of SOC differences between adjacent battery modules among the battery modules 1 to n decreases.

[0040] Battery modules 1 to n can perform wireless charging operations with adjacent battery modules under the control of RBMS 150. Specifically, battery module 1 can transmit power to or receive power from battery module 2 under the control of RBMS 150. MBMS 10 can control battery module 1 based on information received from RBMS 150, causing battery module 1 to transmit power to or receive power from battery module 2. Battery module 1 can transmit or receive power via its antenna.

[0041] Battery module 2 can transmit power to or receive power from battery module 1 under the control of RBMS 150. Battery module 2 can transmit power to or receive power from battery module 1 via an antenna located on one surface facing battery module 1. However, unlike battery module 1, which performs a wireless charging operation with one battery module 2, battery module 2 can perform a wireless charging operation with battery modules 1 and 3. Battery module 2 can be a battery module located between battery modules 1 and 3. That is, each of the remaining battery modules, except for battery modules 1 and n located at the edge, can perform a wireless charging operation with the two battery modules located closest to each other.

[0042] Figure 2a and 2b It shows Figure 1 A conceptual diagram of the structure of the battery module 2. Figure 2a is a perspective view showing the structure of the battery module 2, Figure 2b It is a side view showing the structure of the battery module 2 .

[0043] The battery module 2 may include charge / discharge circuits 21 and 22, an antenna 23, an antenna 24, battery cells (not shown), and Figure 1 MBMS 20.

[0044] MBMS 20 can measure the voltage of the battery cells through the charge / discharge circuits 21 and 22. MBMS 20 can measure the voltage of each of the battery cells or measure the voltage of the battery module 2. The voltage of the battery module 2 can be the sum of the voltages of the battery cells. Figure 1 As described above, the MBMS 20 may calculate the SOC of the battery module 2 based on the measured voltage value.

[0045] In order to Figure 1 To wirelessly charge battery modules 1 and 3, battery module 2 may include antennas 23 and 24 on surfaces facing battery modules 1 and 3, respectively. Battery module 2 may transmit power to or receive power from battery module 1 via antenna 23 located on the surface facing battery module 1. Furthermore, battery module 2 may transmit power to or receive power from battery module 3 via antenna 24 located on the surface facing battery module 3.

[0046] Figure 3 is a diagram showing a method according to an embodiment of the present invention. Figure 1 A block diagram of the battery module 2 configuration.

[0047] The battery module 2 may include an MBMS 20 , charge / discharge circuits 21 and 22 , antennas 23 and 24 , and battery cells 25 .

[0048] MBMS 20 can obtain information about battery cells 25. MBMS 20 can send Figure 1 The RBMS 150 outputs information about the battery cells 25 . Figure 1 The RBMS 150 can control the Figure 1 Wireless charging between battery modules 1 to n.

[0049] Under the control of the RBMS 150, the MBMS 20 may control the charge / discharge circuits 21 and 22 to transmit power to the battery module 1 and / or the battery module 3, or may control the charge / discharge circuits 21 and 22 to receive power from the battery module 1 and / or the battery module 3. Under the control of the MBMS 20, the charge / discharge circuits 21 and 22 may output power to the battery modules 1 and 3 through the antennas 23 and 24, or may receive power from the battery modules 1 and 3.

[0050] The charge / discharge circuits 21 and 22 may charge the battery cell 25 using power received through the antennas 23 and 24. In addition, the charge / discharge circuits 21 and 22 may output power obtained from the battery cell 25 through the antennas 23 and 24.

[0051] Figure 4 is a diagram showing a method according to an embodiment of the present invention. Figure 1 Conceptual diagram of wireless charging between battery modules 1 to n. Figure 4 , describe the use of Figure 1 The RBMS 150 sets the direction and size of wireless charging between the battery modules 1 to n.

[0052] Any one of the battery modules 1 to n can be wirelessly charged with one or more battery modules that are close to each other among the remaining battery modules. For example, battery module 2 can be wirelessly charged with battery modules 1 and 3 on either side of the battery modules 1 to n arranged in a line.

[0053] The RBMS 150 may receive information on the SOC values ​​of the battery modules 1 to n. Figure 4 In the description, the SOC values ​​of battery modules 1 to n are A(%), B(%), C(%), D(%) to N(%), respectively.

[0054] In reference Figure 4 In the description, the wireless charging efficiency between battery module a and battery module b is expressed as “k ab The wireless charging efficiency k between battery module a and battery module b is abIt can be the amount of power output from the transmitting battery module relative to the power received by the receiving battery module, among battery modules a and b. Among battery modules a and b, the transmitting battery module is the battery module that transmits power during wireless charging, and the receiving battery module is the battery module that receives power from the transmitting battery module. For example, the wireless charging efficiency between battery module 1 and battery module 2 is expressed as 'k 12 '.

[0055] In this specification, during wireless charging between battery module a and battery module b, the charging power transferred between battery module a and battery module b is expressed as “e ab Charging power e ab The absolute value of indicates the amount of charging power moved between battery module a and battery module b, and the charging power e ab The sign of indicates the direction of the charging power moving between battery module a and battery module b. ab When it is a positive number, battery module a can send charging power e to battery module b. ab The absolute value of the same amount of electricity. When charging power e ab When it is a negative number, battery module b can send charging power e to battery module a. ab The absolute value is the same as the electricity.

[0056] The RBMS 150 can calculate the charging power e based on the following [Equation 1] 12 to e mn .

[0057] [Equation 1]

[0058]

[0059] In [Equation 1], 'E0' may represent conversion power. The RBMS 150 may calculate the conversion power E0 based on the following [Equation 2]. The converted power E0 may represent the amount of power required to charge the battery module.

[0060] [Equation 2]

[0061] E0 [Wh] = Battery module capacity [Ah] × Battery module driving voltage [V]

[0062] The RBMS 150 may calculate the charging power e based on the information received from the battery modules 1 to n, [Equation 1], and [Equation 2]. 12 to e mn The RBMS 150 may output information about the charging power e to the battery module related to the charging power among the battery modules 1 to n. 12 to e mnFor example, the RBMS 150 may output information about the charging power e to the battery modules 1 and 2. 12 Each of the battery modules 1 to n may perform a wireless charging operation based on the information received from the RBMS 150.

[0063] Wireless charging efficiency k between battery modules a and b ab The wireless charging efficiency k between the battery modules 1 to n may be affected by the distance between the battery modules a and b, the antenna types of the battery modules a and b, the number of turns of the coil constituting the antenna, etc. Since the battery modules 1 to n included in one battery rack 100 have substantially the same structure, the wireless charging efficiency k between the battery modules 1 to n is 12 、k 23 、k 34 to k mn Therefore, for calculation convenience, the RBMS 150 may assume that the wireless charging efficiency k between battery modules 1 to n is 12 、k 23 、k 34 to k mn In this case, the RBMS 150 can calculate the charging power e based on the following [Equation 3] 12 to e mn .

[0064] [Equation 3]

[0065]

[0066] However, the present invention is not limited thereto. The RBMS 150 considers both the convenience of calculation and the accuracy of calculation, and assumes that the wireless charging efficiency k 12 、k 23 、k 34 to k mn Only some of the wireless charging efficiencies are the same value to calculate the charging power e 12 to e mn .

[0067] Figure 5a is a diagram showing the Figure 1 The RBMS 150 calculates the charging power e 12 to e 34 Picture. Figure 5b It shows that according to Figure 5a The charging power e calculated in 12 to e 34 A graph of charging power moving between battery modules 1 to 4.

[0068] In reference Figure 5a and 5bIn the description of , for convenience of calculation, RBMS 150 assumes that the wireless charging efficiency among battery modules 1 to 4 has the same value of "0.7". Figure 5a and Figure 5b In the description, it is assumed that the SOC values ​​of battery modules 1 to 4 are 70%, 90%, 80% and 60% respectively, and the conversion power E0 is 10*10 4 [mWh].

[0069] In reference Figure 5a and 5b In the description, for convenience of explanation, it is assumed that wireless charging is performed between the four battery modules 1 to 4, but the present invention is not limited thereto.

[0070] RBMS 150 can be based on reference Figure 4 The charging power e is calculated using the equation [2] 12 to e 34 As a result of the calculation, the charging power e 12 to e 34 The values ​​can be -270 [Wh], 1540 [Wh], and 1840 [Wh], respectively. Based on the calculation results, RBMS 150 can control battery module 2 and battery module 1 so that 270 [Wh] is output from battery module 2 to battery module 1. RBMS 150 can control battery module 2 and battery module 3 so that 1540 [Wh] is output from battery module 2 to battery module 3. RBMS 150 can control battery module 3 and battery module 4 so that 1840 [Wh] is output from battery module 3 to battery module 4.

[0071] Since wireless charging is performed between the battery modules 1 to 4 under the control of the RBMS 150 , cell balancing between the battery modules 1 to 4 can be achieved.

[0072] Figure 6 It shows Figure 5b Flowchart of wireless charging operation between battery modules 1 to 4.

[0073] refer to Figure 6 , will describe Figure 5b The battery modules 1 to 4 perform a wireless charging operation under the control of the RBMS 150.

[0074] In operation S110 , the battery module 1 may output information regarding an SOC value of the battery module 1 to the RBMS 150 .

[0075] In operation S112 , the battery module 2 may output information regarding the SOC value of the battery module 2 to the RBMS 150 .

[0076] In operation S114 , the battery module 3 may output information regarding the SOC value of the battery module 3 to the RBMS 150 .

[0077] In operation S116 , the battery module 4 may output information regarding the SOC value of the battery module 4 to the RBMS 150 .

[0078] In operation S200, the RBMS 150 may calculate the charging power e based on information (eg, SOC values) received from the battery modules 1 to 4. 12 、e 23 and e 34 However, the present invention is not limited thereto, and the battery modules 1 to 4 may output the voltage of each of the battery cells or the sum of the voltages of the battery cells. The RBMS 150 may calculate the SOC values ​​of the battery modules 1 to 4 based on the information received from the battery modules 1 to 4, and calculate the charging power e 12 、e 23 and e 34 .

[0079] In operation S310, the RBMS 150 may output information about the charging power e to the battery module 1. 12 The battery module 1 may prepare to receive power based on the information received from the RBMS 150.

[0080] In operation S320, the RBMS 150 may output information about the charging power e to the battery module 2. 12 and e 23 The battery module 2 may prepare to output power based on the information received from the RBMS 150.

[0081] In operation S330, the RBMS 150 may output information about the charging power e to the battery module 3. 23 and e 34 The battery module 3 may prepare to output power and prepare to receive power based on the information received from the RBMS 150.

[0082] In operation S340, the RBMS 150 may output information about the charging power e to the battery module 4. 34 The battery module 4 may prepare to receive power based on the information received from the RBMS 150.

[0083] In operation S400, the battery module 2 may output the charging power e to the battery module 1 based on the information received through operation S320. 12 .

[0084] In operation S450, the battery module 1 may receive the charging power e from the battery module 2 based on the information received through operation S320. 12The battery module 1 can be charged by using the charging power e received from the battery module 2. 12 The battery cells of the battery module 1 are charged.

[0085] In operation S500, the battery module 2 may output the charging power e to the battery module 3 based on the information received through operation S320. 23 .

[0086] In operation S550, the battery module 3 may receive the charging power e from the battery module 2 based on the information received through operation S330. 23 The battery module 3 can be charged by using the charging power e received from the battery module 2. 23 The battery cells of the battery module 3 are charged.

[0087] In operation S600, the battery module 3 may output the charging power e to the battery module 4 based on the information received through operation S330. 34 .

[0088] In operation S650, the battery module 4 may receive the charging power e from the battery module 3 based on the information received through operation S340. 34 The battery module 4 can be charged by using the charging power e received from the battery module 3. 34 The battery cells of the battery module 4 are charged.

[0089] Figure 7 It is used to explain another embodiment Figure 1 Conceptual diagram of wireless charging between battery modules 1 to 4. For ease of explanation, although only Figure 1 Wireless charging is performed between four battery modules 1 to 4 among the battery modules 1 to n, but it is obvious that the wireless charging method can be extended to battery modules 1 to n.

[0090] As reference Figure 4 As described above, any one of battery modules 1 to 4 can wirelessly charge one or more battery modules adjacent to each other. For example, battery module 2 can be wirelessly charged by battery modules 1 and 3 on either side of battery modules 1 to 4 arranged in a line.

[0091] The SOC values ​​of the battery modules 1 to 4 are A(%), B(%), C(%), and D(%), respectively. The RBMS 150 may receive information on the SOC values ​​of the battery modules 1 to 4.

[0092] refer to Figure 7 During wireless charging between battery module a and battery module b, the charging power transferred between battery module a and battery module b is expressed as “p ab "Charging power p abThe absolute value of indicates the amount of charging power moved between battery module a and battery module b. The charging power p ab The sign of indicates the direction of the charging power moving between battery module a and battery module b. ab When it is a positive number, battery module a can send charging power p to battery module b. ab The absolute value of the same amount of electricity. When the charging power p ab When it is a negative number, battery module b can send the same charging power p to battery module a. ab The absolute value is the same as the electricity.

[0093] The RBMS 150 can calculate the charging power p based on the following [Equation 4] ab .

[0094] [Equation 4]

[0095] P ab =(SOC value of battery module a - SOC value of battery module b) × 1 / 100 × E0 × H0

[0096] The conversion power E0 in [Equation 4] can be calculated using [Equation 2]. The conversion value h0 in [Equation 4] can be determined based on the wireless charging efficiency between battery modules a and b, the distance between battery modules a and b, the SOC values ​​of battery modules a and b, the antenna types of battery modules a and b, the number of turns of the coils constituting the antennas, and the like. The conversion value h0 may vary based on the SOC values ​​of battery modules a and b.

[0097] Figure 8 It is shown according to the reference Figure 7 A diagram depicting the method for moving charging power between battery modules 1 to 4.

[0098] In reference Figure 7 In the description, for the convenience of calculation in RBMS 150, it is assumed that the conversion power E0 is 10 4 [Wh]. In reference Figure 8 In the description, for convenience of explanation, it is assumed that wireless charging is performed between the four battery modules 1 to 4, but the present invention is not limited thereto.

[0099] RBMS 150 can be based on reference Figure 7[Equation 4] described above calculates charging powers p12 to p34. As a result of the calculation, charging powers p12 to p34 may be -2000*h0[Wh], 1000*h0[Wh], and 2000*h0[Wh], respectively. Based on the calculation results, RBMS 150 may control battery module 2 and battery module 1 so that 2000*h0[Wh] is output from battery module 2 to battery module 1. RBMS 150 may control battery module 2 and battery module 3 so that 1000*h0[Wh] is output from battery module 2 to battery module 3. RBMS 150 may control battery module 3 and battery module 4 so that 2000*h0[Wh] is output from battery module 3 to battery module 4.

[0100] Since wireless charging is performed between the battery modules 1 to 4 under the control of the RBMS 150 , cell balancing between the battery modules 1 to 4 can be achieved.

[0101] Figure 9 is a diagram showing a hardware configuration of a BMS according to an embodiment of the present invention;

[0102] refer to Figure 9 , the BMS 800 may include: a microcontroller (MCU) 810 for controlling various processes and each configuration; a memory 820 on which an operating system program and various programs (e.g., a battery diagnosis program, a voltage approximation calculation program, etc.) are recorded; an input / output interface 830 for providing an input interface and an output interface between battery cell modules and / or semiconductor switching elements; and a communication interface 840 capable of communicating with the outside through a wired / wireless communication network. In this way, the computer program according to the present invention may be recorded in the memory 820 and processed by the microcontroller 810, and may be implemented to execute, for example Figure 3 Modules for each functional block shown in .

[0103] The above description is of specific embodiments for carrying out the present invention. The present invention will include not only the above-described embodiments, but also simple design changes or easily changeable embodiments. In addition, the present invention will include techniques that can be easily modified and implemented using the embodiments. Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be defined by the claims described below and the claims and equivalents thereof.

Claims

1. A battery management system comprising: a communication unit configured to receive information about a first SOC of the first battery module, information about a second SOC of the second battery module, and information about a third SOC of the third battery module; and a controller configured to control a first wireless charging between the first battery module and the second battery module and a second wireless charging between the second battery module and the third battery module, for balancing the first SOC, the second SOC, and the third SOC, The first wireless charging is to wirelessly transmit power from one of the first battery module and the second battery module to the other battery module. The second wireless charging is to wirelessly transmit power from one of the second battery module and the third battery module to the other battery module. The controller determines a first direction and a first size of the first wireless charging, and a second direction and a second size of the second wireless charging according to the determinant. Determinant Among them, E0 is a constant, e 12 The sign and magnitude are the first direction and the first magnitude, e 23 The sign and magnitude are the second direction and the second magnitude, soc1 is the first SOC, soc2 is the second SOC, soc3 is the third SOC, k 12 is the first wireless charging efficiency between the first battery module and the second battery module, k 23 is a second wireless charging efficiency between the second battery module and the third battery module.

2. The battery management system according to claim 1, wherein: The controller controls the first wireless charging and the second wireless charging so that a sum of an absolute value of a difference between the first SOC and the second SOC and an absolute value of a difference between the second SOC and the third SOC decreases.

3. The battery management system according to claim 1, wherein: The first SOC is the sum of the SOCs of the first battery cells in the first battery module. The second SOC is the sum of the SOCs of the second battery cells in the second battery module. The third SOC is the sum of the SOCs of the third battery cells in the third battery module.

4. The battery management system according to claim 1, wherein: A battery module is located between the first battery module and the third battery module, Wherein, the one battery module is the second battery module.

5. The battery management system according to claim 1, wherein: The controller controls the first wireless charging and the second wireless charging based on the first SOC, the second SOC, the third SOC, a first wireless charging efficiency between the first battery module and the second battery module, and a second wireless charging efficiency between the second battery module and the third battery module. The first wireless charging efficiency is determined based on the distance between the first battery module and the second battery module, the type of antenna used for power transmission and reception of the first battery module and the second battery module, and the number of turns of the coil constituting the antenna for power transmission.

6. The battery management system according to claim 5, wherein: The controller controlling the first battery module or the second battery module so that when the first direction is a negative number, the first amount of power is transmitted from the second battery module to the first battery module, and when the first direction is a positive number, the first amount of power is transmitted from the first battery module to the second battery module, and The second battery module or the third battery module is controlled so that when the second direction is a negative number, the second amount of power is sent from the third battery module to the second battery module, and when the second direction is a positive number, the second amount of power is sent from the second battery module to the third battery module.

7. The battery management system according to claim 6, wherein: E0 is determined by the equation, equation E0 [Wh] = capacity of the first battery module [Ah] × driving voltage of the first battery module [V].

Images