Energy storage system and communication method thereof
By generating and comparing authentication keys in the controller and BMS of the energy storage system, the problems of low communication security and computing resource usage efficiency in the prior art are solved, and effective verification and secure communication of control commands are realized.
Patent Information
- Application Number
- CN202380040668.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-09-25
- Filing Date
- 2023-10-11
- Publication Date
- 2024-12-27
Smart Images
Figure CN119213733A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an energy storage system, and in particular to an energy storage system capable of performing safe communication and a communication method thereof. Background Art
[0002] With problems such as increased environmental damage and consumption of natural resources, systems that can store electricity and efficiently utilize the stored electricity are increasingly attracting attention. In addition, interest in renewable energy sources that do not cause pollution in the process of generating electricity is also increasing. An energy storage system (ESS) is a system that links renewable energy, power storage batteries, and existing grid power, and many studies and developments thereon are being conducted in line with today's environmental changes. That is, ESS is a device that improves the efficiency of power use by storing the generated power in a storage device such as a battery and supplying power when power is needed. Therefore, ESS is equipped with a battery that stores power and a device that efficiently manages and controls the battery.
[0003] The ESS may include a plurality of batteries for storing electricity, and the ESS may include at least one battery bank. In addition, each battery bank may include a plurality of battery racks, and each of the plurality of battery racks may include a plurality of battery modules. In addition, each battery module includes a plurality of battery cells. That is, a plurality of battery cells may be bundled to form one battery module, a plurality of battery modules may be bundled to form one battery rack, a plurality of battery racks may be bundled to form one battery bank, and at least one battery bank may form an ESS.
[0004] For ESS, it is important to efficiently manage various matters such as battery charging, discharging, and single-cell balancing. By efficiently managing the battery, the life of the battery can be extended, and power can be stably supplied to the load. For this purpose, the ESS may be equipped with a battery management system (BMS). The BMS monitors the voltage, current, and temperature of the battery, and maintains and manages the battery under optimal conditions. In addition, the BMS manages the battery system including the battery and the peripheral devices of the battery, such as predicting the battery replacement time and detecting battery problems in advance. The BMS may be provided in each of the battery pack, the battery rack, and the battery module. That is, the battery bank, the battery rack, and the battery module include a bank BMS (BBMS), a rack BMS (RBMS), and a module BMS (MBMS), respectively. In addition, the ESS includes a battery system controller (BSC) as the uppermost controller that controls the entire ESS. Therefore, in the ESS, a hierarchical battery management system that continuously leads to the BSC, BBMS, RBMS, and MBMS is implemented. For example, a control command from the BSC is transmitted to the BBMS, RBMS, and MBMS to manage the battery.
[0005] At the same time, various data collected by the BMS for various research and development can be stored on a remote central server, etc. That is, for ESS, there are more and more cases where its battery control controller such as BSC is exposed to the public Internet network for remote control, remote monitoring, etc. However, when the controller is exposed, ESS has security vulnerabilities such as malware infection and attacks from hackers. In addition, due to the nature of ESS processing huge amounts of electrical energy, intimidation or arbitrary control by hackers may cause significant physical damage. The above problems can be avoided by applying encryption technology to the communication between the controller and the lower-level BMS. However, encrypting the entire communication requires a large amount of computing operations, which puts a great burden on the battery monitoring IC (BMIC) using relatively lower computing power than a personal computer (PC).
[0006] In this regard, Patent Document 1 proposes a battery pack equipped with a wireless communication module and discloses a technology for authenticating a connected external electronic device and a battery pack by generating an authentication number of the battery pack, and Patent Document 2 discloses a battery system that uses an authentication key to perform mutual authentication between a master BMS and a slave BMS.
[0007] In addition, patent document 3 discloses a battery management system that generates an authentication code and transmits battery measurement data together with the authentication code when transmitting a data packet to an external device, and patent document 4 discloses a method for generating a secret key, the method comprising: generating a first secret key using a voltage measured in a battery and transmitting the first secret key to an external device; receiving a second secret key generated using the first secret key from the external device; and generating a final secret key by operating using the first secret key and the second secret key.
[0008] However, in the above-mentioned related art, no method has been proposed for verifying the authenticity of a control command by checking an authentication key used to transmit a control command between a battery management device and an upper-level controller, and the entire data is encrypted when generating an authentication key and encrypted data, and therefore there is a problem of inefficient use of computing resources.
[0009] The related technologies are as follows.
[0010] Patent Document 1: KR 10-2018-0056460 A
[0011] Patent Document 2: KR 10-2014-0019629 A
[0012] Patent document 3: KR 10-2021-0051462 A. Summary of the invention
[0013] Technical issues
[0014] The present invention provides an energy storage system and a communication method thereof capable of performing safe communication between a controller and a lower-level BMS.
[0015] The present invention provides an energy storage system and a communication method thereof for determining the authenticity of a control command from a controller by generating a first authentication key and a second authentication key in the controller and a lower-level BMS respectively and comparing the authentication keys.
[0016] In addition, the present invention provides a communication method between a controller and a BMS, which generates an authentication key by efficiently using computing resources and uses the generated authentication key.
[0017] Technical Solution
[0018] An energy storage system according to an embodiment of the present invention includes: a plurality of battery management systems (BMS), each of which manages a plurality of battery cells; and an upper controller that transmits a predetermined control command to the plurality of BMSs, wherein the upper controller generates authentication key information and a first authentication key using battery cell information provided from the BMSs, and the BMS generates a second authentication key using the authentication key information from the upper controller, and then determines the authenticity of the control command from the upper controller by comparing the first authentication key and the second authentication key. The BMS may provide battery cell voltage information about any N battery cells among all battery cells managed by the BMS together with the battery cell information to the upper controller, the upper controller may generate authentication key information using the value of the number N of battery cells whose information is stored, and then generate the first authentication key using the battery cell information and the authentication key information, and the BMS may generate the second authentication key using the value of the number N of battery cells whose information is stored and the received authentication key information.
[0019] The upper-level controller may include: a communication unit that receives battery cell information including voltage information about all battery cells controlled by at least one BMS among a plurality of BMSs and voltage information about any N battery cells, and transmits generated authentication key information and a first authentication key to the BMS; an authentication key information generation unit that generates authentication key information based on a value of the number N about which voltage information is stored and the received battery cell information; and a first authentication key generation unit that generates a first authentication key using the battery cell information and the authentication key information.
[0020] The authentication key information generation unit may generate a key information including Any integer P and satisfying The authentication key information of any integer I.
[0021] The first authentication key generation unit may generate the first authentication key by generating a first battery cell voltage sum value by adding voltages of a predetermined number of battery cells selected from all battery cell information using authentication key information, adding the ID of the BMS to the first battery cell voltage sum value, and then performing a crc16 hash operation.
[0022] The first battery cell voltage sum value may be generated by adding the voltages from the P+0th battery cell to the P+1th battery cell from the battery cell information. Here, P is a voltage that satisfies Any integer, I is a is an arbitrary integer, and N is the number of battery cells whose information is stored.
[0023] The BMS may include: a memory unit that stores voltage information about any N battery cells among all battery cells managed by the BMS; a communication unit that transmits battery cell information including voltage information about all battery cells managed by the BMS and a value of the number N of battery cells about which the voltage information is stored to an upper-level controller, and receives authentication key information and a first authentication key from the upper-level controller; a second authentication key generation unit that generates a second authentication key based on the authentication key information and the value of the number N of battery cells about which the voltage information is stored; an authentication key comparison unit that compares the first authentication key and the second authentication key; and a control unit that determines the authenticity of a control command from the upper-level controller based on a comparison result of the authentication key comparison unit.
[0024] The second authentication key generation unit may generate the second authentication key by generating a second cell voltage sum value by adding voltages of a predetermined number of battery cells selected from any battery cell information using authentication key information, adding the ID of the BMS to the second cell voltage sum value, and then performing a crc16 hash operation.
[0025] The second cell voltage sum value may be generated by adding the voltages from the P+0th cell to the P+1th cell from the cell information. Here, P is a cell voltage that satisfies Any integer, I is a is an arbitrary integer, and N is the number of battery cells whose information is stored.
[0026] According to another embodiment of the present invention, a communication method for an energy storage system includes: receiving battery cell information and voltage information about any battery cell from a BMS by an upper controller; generating authentication key information and a first authentication key by the upper controller using the battery cell information and voltage information about any battery cell; receiving the authentication key information from the upper controller by the BMS to generate a second authentication key and comparing the second authentication key with the first authentication key; and executing a control command from the upper controller by the BMS according to a comparison result of the first authentication key and the second authentication key.
[0027] Authentication key information may include Any integer P and satisfying Any integer I.
[0028] The first authentication key may be generated by generating a first cell voltage sum value by adding voltages of a predetermined number of cells selected from all cell information using authentication key information, adding the BMS ID to the first cell voltage sum value, and then performing a crc16 hash operation.
[0029] The first battery cell voltage sum value may be generated by adding the voltages from the P+0th battery cell to the P+1th battery cell from the battery cell information. Here, P is a voltage that satisfies Any integer, I is a is an arbitrary integer, and N is the number of battery cells whose information is stored.
[0030] The second authentication key may be generated by generating a second cell voltage sum value by adding voltages of a predetermined number of cells selected from arbitrary cell information using authentication key information, adding the ID of the BMS to the second cell voltage sum value, and then performing a crc16 hash operation.
[0031] The second cell voltage sum value may be generated by adding the voltages from the P+0th cell to the P+1th cell from the cell information. Here, P is a cell voltage that satisfies Any integer, I is a is an arbitrary integer, and N is the number of battery cells whose information is stored.
[0032] According to another embodiment of the present invention, a communication method for an energy storage system is provided, the communication method comprising: transmitting battery cell information including voltage information about all battery cells from a BMS to an upper-level controller; storing voltage information about any N battery cells among all battery cells managed by the BMS; transmitting the stored number N of battery cells to the upper-level controller; generating authentication key information by the upper-level controller using the value of the number N of battery cells about which voltage information is stored; generating a first authentication key using the battery cell information and the authentication key information; transmitting the first authentication key and the authentication key information to the BMS; generating a second authentication key by the BMS using the number N of battery cells about which voltage information is stored and the authentication key information; and determining the authenticity of a control command from the upper-level controller by comparing the first authentication key with the second authentication key.
[0033] Beneficial Effects
[0034] In the present invention, the upper controller generates authentication key information and a first authentication key using battery cell information provided from a battery management system (BMS), and when the authentication key information and the first authentication key are provided to the BMS, the BMS generates a second authentication key using the authentication key information, and then determines the authenticity of the control command from the upper controller by comparing the first authentication key and the second authentication key. In this case, when the BMS provides the battery cell information to the upper controller, the BMS stores battery cell voltage information about any N battery cells among all battery cells managed by the BMS in a memory unit, and provides the battery cell voltage information to the upper controller, and the upper controller generates a predetermined authentication key information using the number value of the battery cell whose information is stored. In addition, the upper controller generates a first authentication key using the battery cell information and the predetermined authentication key information, and the BMS generates a second authentication key using the number value of the battery cell whose information is stored and the received authentication key information.
[0035] As described above, secure communication between the BMS and the controller can be performed by comparing the first authentication key and the second authentication key generated by the upper controller and the lower BMS, respectively, and determining the authenticity of the control command from the controller. In addition, since secure communication can be performed with a small amount of operation, it can also be operated using a battery monitoring IC (BMIC). BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Figure 1 is a block diagram for describing the configuration of an energy storage system according to one embodiment of the present invention.
[0037] Figure 2is a block diagram for describing a configuration of a battery management system (BMS) which is one component of an energy storage system according to one embodiment of the present invention.
[0038] Figure 3 is a block diagram for describing the configuration of a superior controller as a component of an energy storage system according to an embodiment of the present invention.
[0039] Figure 4 is a flowchart for describing a communication method of an energy storage system according to an embodiment of the present invention. DETAILED DESCRIPTION
[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms. Embodiments of the present invention are only provided to allow the present invention to be complete and to fully inform those skilled in the art of the scope of the present invention.
[0041] 1. Energy storage system for performing authentication key communication according to the present invention
[0042] Figure 1 is a block diagram for describing the configuration of an energy storage system according to an embodiment of the present invention, Figure 2 is a block diagram for describing a configuration of a battery management system (BMS) which is a component of an energy storage system according to an embodiment of the present invention, and Figure 3 is a block diagram for describing the configuration of a superior controller as a component of an energy storage system according to an embodiment of the present invention.
[0043] refer to Figure 1 , an energy storage system according to one embodiment of the present invention may include a plurality of BMSs 100a, 100b, ..., 100n for managing a battery 10; 100; and an upper controller 200 for controlling the battery 10 through the plurality of BMSs 100. The upper controller 200 may be connected to a server or the like through a network, and the network may be a public Internet network such as a cloud service. In the energy storage system, the BMS 100 provides information about the battery 10 to the upper controller 200, and receives a control command for controlling the battery 10 from the upper controller 200.
[0044] In addition, in the energy storage system according to the present invention, the upper controller 200 generates a first authentication key and authentication key information using the battery cell information provided from the BMS 100, and provides the first authentication key and authentication key information to the BMS 100, and the BMS 100 generates a second authentication key using the authentication key information, and then determines the authenticity of the control command from the upper controller 200 by comparing the first authentication key and the second authentication key. In this case, when the first authentication key and the second authentication key are the same, it is determined that the control command has been transmitted from the upper controller 200, and when the first authentication key and the second authentication key are not the same, it is determined that the control command is false. The energy storage system according to one embodiment of the present invention will be described in more detail for each component as follows.
[0045] (1) Battery
[0046] The battery 10 can be charged by receiving power, and the charged electric energy can be discharged and supplied to the power consumption device. That is, the battery 10 can be charged and discharged, and can be used as an energy source for the power consumption device. Here, the battery 10 may include a plurality of battery cells. Of course, the battery 10 may be a battery module, a battery rack, or a battery library. That is, when the BMS 100 of the present invention is a module BMS, the battery 10 may be a battery module, when the BMS 100 is a rack BMS, the battery 10 may be a battery rack, and when the BMS 100 is a library BMS, the battery 10 may be a battery library. Therefore, the battery 10 may be a battery module in which a plurality of battery cells are bundled, a battery rack in which a plurality of battery modules are bundled, or a battery library in which a plurality of battery racks are bundled. At the same time, a plurality of battery cells as the basic components of the battery 10 may be connected in series and / or in parallel in various ways. Of course, a plurality of battery modules each including a plurality of battery cells may also be connected in series and / or in parallel. Here, the battery cells may include lithium-ion batteries. However, the battery cell may be composed not only of a lithium ion battery but also of a lithium polymer battery, a nickel cadmium battery, a nickel-hydrogen battery, and a nickel-zinc battery.
[0047] (2) Battery Management System (BMS)
[0048] The BMS 100 estimates the state of the battery 10 and manages the battery 10 using the estimated state information. For example, the BMS 100 measures the state of the battery 10, such as voltage, current, and temperature, and uses the state information to estimate the state of charge (SOC), state of health (SOH), and state of power (SOP). SOC represents the remaining capacity of the battery, and accurate prediction of the SOC makes it possible to predict the future driving distance. SOH represents the capacity of the battery, which means the aging state of the battery and affects the number of times the battery is charged and discharged. SOP means the maximum power that the battery can support. The prediction of the maximum power helps prevent overcharging or heat loss of the battery. Using the state information, the BMS 100 controls the charging or discharging of the battery 10. To this end, Figure 2As illustrated in FIG. 1 , the BMS 100 may include a sensing unit 110 for sensing the state of the battery 10, a control unit 120 for generating a control signal for controlling the charging and discharging of the battery 10 according to the state of the battery 10 measured by the sensing unit 110, and a switch unit 130 for switching the connection between the battery 10 and an external power source or a power consumption device to charge and discharge the battery according to the control signal from the control unit 120. In addition, the BMS 100 according to one embodiment of the present invention transmits battery cell information to the upper controller 200, and stores information about at least one randomly selected battery cell (i.e., N battery cells). In addition, the BMS 100 receives a first authentication key and authentication key information from the upper controller 200, and generates an authentication key by combining the stored battery cell information and the received authentication key information. In addition, the BMS 100 compares the generated second authentication key with the received first authentication key, executes a command received from the upper controller 200 when the authentication keys are the same, and ignores the command received from the upper controller 200 when the authentication keys are not the same. To this end, the BMS 100 according to one embodiment of the present invention may include a communication unit 140 for communicating with the upper controller 200, a memory unit 150 for storing information about the battery 10, a second authentication key generation unit 160 for generating a second authentication key, and an authentication key comparison unit 170 for comparing the first authentication key and the second authentication key. In this case, the control unit 120 determines the authenticity of the control command according to the comparison result of the authentication key comparison unit 170. That is, as a comparison result of the authentication key comparison unit 170, when the first authentication key and the second authentication key are the same, the control unit 120 executes the control command from the upper controller 200, and when the first authentication key and the second authentication key are not the same, the control unit 120 determines that the control command is false and ignores the control command. In addition, the control unit 120 can control each component of the BMS 100 and the switch unit 130 for charging and discharging the battery 10. That is, the control unit 120 may control the communication unit 140 to provide the battery cell information to be provided to the upper controller 200, may store the battery cell information in the memory unit 150, or may execute a control command from the upper controller 200 according to the comparison result of the authentication key comparison unit 170. As described above, the sensing unit 110, the control unit 120, and the switching unit 130 are provided to control the charging and discharging of the battery 10, and the communication unit 140, the memory unit 150, the second authentication key generation unit 160, and the authentication key comparison unit 170 are provided to generate and compare authentication keys.Finally, in the energy storage system (ESS) for secure communication of the present invention, the BMS 100 may include a control unit 120 , a communication unit 140 , a memory unit 150 , a second authentication key generation unit 160 , and an authentication key comparison unit 170 .
[0049] Meanwhile, the BMS 100 may be a plurality of module BMSs (MBMSs) for each managing a predetermined number of battery modules, may be a plurality of rack BMSs (RBMSs) for each managing a predetermined number of module BMSs (MBMSs), or may be at least one bank MBS (BBMS) for each managing a predetermined number of rack BMSs (RBMSs). That is, in the present invention, at least one of the module BMSs, the rack BMSs, and the bank BMSs may generate and compare an authentication key through communication with the upper controller 200 to confirm the authenticity of a control command from the upper controller 200.
[0050] The BMS 100 according to one embodiment of the present invention will be described in more detail with respect to each component as follows.
[0051] (2)-1. Sensing unit
[0052] A sensing unit 110 may be provided to sense the state of the battery 10. For example, the sensing unit 110 may sense the current, voltage, temperature, etc. of the battery 10. In addition, the sensing unit 110 may sense the state of the battery module and the battery cell, such as the current and voltage. That is, the state of each of the plurality of battery cells may be sensed, or the state of the battery module in which the plurality of battery cells are bundled may be sensed. For this purpose, the sensing unit 110 may include a plurality of sensors. That is, the sensing unit 110 may include at least one current sensor, at least one voltage sensor, and at least one temperature sensor. The voltage sensor, the current sensor, and the temperature sensor periodically measure the voltage, current, and temperature of the battery 10 under the control of the control unit 120, and provide the measurement results to the control unit 120. Here, the voltage sensor generates a signal corresponding to the voltage applied between the positive and negative electrodes of the battery 10, and provides it to the control unit 120. In addition, the current sensor as a sensing resistor or a Hall sensor generates a signal corresponding to the magnitude of the charging current, and provides the generated signal to the control unit 120. The current sensor may measure not only the charging current, but also the magnitude of the discharging current. The temperature sensor may be, for example, a thermal coupler for measuring temperature. The temperature sensor generates a signal corresponding to the temperature of the battery 10 and provides the generated signal to the control unit 120 .
[0053] (2)-2. Control unit
[0054] The control unit 120 may control the battery 10 according to the state of the battery 10 measured by the sensing unit 110. Specifically, the control unit 120 may perform various functions such as life management of the battery 10, capacity control of the battery 10, battery balancing, etc. In addition, the control unit 120 may control the charging and discharging of the battery 10 by generating a control signal according to the voltage measured from the sensing unit 110 and controlling the switch unit 130 between the battery 10 and the external power source, thereby preventing overcharging or overdischarging of the battery cells. For example, the control unit 120 may compare a first set voltage for stopping the charging operation and a second set voltage for performing the charging operation with the voltage of the battery 10 measured by the sensing unit 110, generate a control signal for stopping the charging operation of the battery 10 when the measured voltage is higher than or equal to the first set voltage, and generate a control signal for the charging operation of the battery 10 when the measured voltage is lower than or equal to the second set voltage. In addition, the control unit 120 may provide battery cell information to be provided to the upper controller 200, perform an operation according to a control command from the upper controller 200, and control the communication unit 140 for this purpose, that is, the control unit 120 may transmit the battery cell information to the upper controller 200 through the communication unit 140, and receive a control command from the upper controller 200 through the communication unit 140. Then, the control unit 120 selects at least one piece of battery cell information, that is, N pieces of battery cell information, from all the battery cell information, stores the selected battery cell information in the memory unit 150, and transmits to the upper controller 200 the number information N of the battery cells about which the battery cell information is stored. In this case, the battery cell information may include the voltage of the battery cell. In addition, the control unit 120 may determine the authenticity of the control command according to the comparison result of the authentication key comparison unit 170 comparing the first authentication key from the upper controller 200 with the second authentication key from the second authentication key generation unit 160, and execute the control command from the upper controller 200.
[0055] (2)-3. Switch unit
[0056] A switch unit 130 may be provided to control the current for charging or discharging the battery 10. That is, a switch unit 130 is provided on the charging and discharging paths to set the charging and discharging paths. In this case, the switch unit 130 may perform charging or discharging according to a control signal of the control unit 120. The switch unit 130 may be made of a semiconductor switching element for controlling the flow of current for charging or discharging. For example, depending on the specifications of the battery 10, at least one field effect transistor (FET), a relay, etc. may be used. As a specific example, the switch unit 130 may include a charging switch and a discharging switch driven according to corresponding control signals of the control unit 120, respectively. In this case, the charging switch and the discharging switch may each be made of a FET.
[0057] (2)-4. Communication unit
[0058] The communication unit 140 may be provided for communication between the BMS 100 and the upper controller 200. That is, the communication unit 140 may be provided to transmit battery cell information, etc. from the BMS 100 to the upper controller 200, and to receive control commands, etc. from the upper controller 200. In addition, the communication unit 140 may receive a first authentication key and authentication key information from the upper controller 200. The control command received from the upper controller 200 through the communication unit 140 may be transmitted to the control unit 120, the authentication key information from the upper controller 200 may be transmitted to the authentication key generation unit 160, and the first authentication key from the upper controller 200 may be transmitted to the authentication key comparison unit 170. Here, the communication unit 140 may communicate with the upper controller 200 by wire or wirelessly; for example, the communication unit 140 may communicate with the upper controller 200 using a controller area network (CAN) method or a local interconnect network (LIN) method.
[0059] (2)-5. Memory unit
[0060] When the battery cell information is transmitted to the upper controller 200, the memory unit 150 stores voltage information about any N battery cells. That is, the memory unit 150 may store any battery cell information selected by the control unit 120 through the control unit 120. In addition, the memory unit 150 may store information such as a unique ID corresponding to the BMS 100, and may store unique characteristic information about the battery 10 for charging and discharging operations of the battery 10. The memory unit 150 may include storage media such as random access memory (RAM), static RAM (SRAM), ferroelectric RAM (FRAM), phase change RAM (PRAM), magnetic RAM (MRAM), flash memory, electrically erasable programmable memory (EEPROM), read-only memory (ROM), and programmable ROM (PROM).
[0061] (2)-6. Second authentication key generation unit
[0062] The second authentication key generation unit 160 generates a second authentication key using any battery cell information stored in the memory unit 150 and the authentication key information received from the upper controller 200 through the communication unit 140. In this case, the authentication key generation unit 160 may generate the second authentication key using the received authentication key information, a predetermined number of battery cell voltages, an ID of the BMS, and the like. For example, the authentication key generation unit 160 may generate the second authentication key in the following manner: a second cell voltage sum value is generated by adding up the voltages of a predetermined number of battery cells selected from any battery cell information using the received authentication key information, adding the ID of the BMS to the second cell voltage sum value, and then performing a crc16 hash operation. In this case, the second cell voltage sum value may be generated by adding up the voltages from the P+0th battery cell to the P+Ith battery cell from the battery cell information. Here, P is a value that satisfies Any integer, I is a is an arbitrary integer, and N is the number of battery cells whose information is stored.
[0063] (2)-7. Authentication key comparison unit
[0064] The authentication key comparison unit 170 compares the second authentication key generated in the second authentication key generation unit 160 with the first authentication key generated in the upper controller 200. That is, the authentication key comparison unit 170 compares the first authentication key and the second authentication key to determine whether the authentication keys are identical. The comparison result of the authentication key comparison unit 170 is transmitted to the control unit 120, and according to the comparison result of the authentication key comparison unit 170, when the first authentication key and the second authentication key are identical, the control unit 120 executes the control command received from the upper controller 200, and when the first authentication key and the second authentication key are not identical, the control unit 120 ignores the control command received from the upper controller 200. In this case, the authentication key comparison unit 170 may transmit different signals to the control unit 120 according to the comparison result of the first authentication key and the second authentication key. For example, when the first authentication key and the second authentication key are identical, a logic high signal may be transmitted to the control unit 120, and when the first authentication key and the second authentication key are not identical, a logic low signal may be transmitted to the control unit 120.
[0065] (3) Upper controller
[0066] The upper controller 200 may be provided to control the ESS. That is, the upper controller 200 may be provided to control a plurality of BMSs 100. The upper controller 200 may transmit a control command for controlling a plurality of batteries 10 to the BMS 100. Thus, the operation of the BMS 100 is controlled based on the control command received from the upper controller 200, and operations such as charging and discharging of the battery 10 may be controlled accordingly. Here, the upper controller 200 may be a battery system controller (BSC) for controlling the ESS. In addition, the upper controller 200 according to one embodiment of the present invention may generate authentication key information for secure communication with the BMS 100, and generate a first authentication key based thereon. To this end, the upper controller 200 periodically receives all battery cell information from a plurality of BMSs 100, and receives a plurality of pieces of battery cell information currently stored in each of the BMSs 100. Then, the upper controller 200 generates predetermined authentication key information using the value of the number of battery cells (i.e., N value) in which the information is stored, and generates a first authentication key using the battery cell information and the authentication key information. In addition, the upper controller 200 transmits the first authentication key and the authentication key information to the BMS 100 .
[0067] (3)-1. Communication unit
[0068] The communication unit 210 may be provided for communication between the upper controller 200 and the BMS 100. In addition, the communication unit 210 may be provided for communication between the upper controller 200 and the server through a network. That is, the communication unit 210 may be provided to receive battery cell information, etc. from the BMS 100, and transmit a control command, etc. from the upper controller 200 to the BMS 100. In addition, the communication unit 210 may transmit the first authentication key and the authentication key information from the upper controller 200 to the BMS 100. The communication unit 210 may communicate with the BMS 100 by wire or wirelessly; for example, the communication unit 210 may communicate with the BMS 100 using a controller area network (CAN) method or a local interconnect network (LIN) method. At the same time, the communication unit 210 may communicate with a server (not shown) through a network, and the communication using the network may use wireless communication. That is, the communication unit 210 may communicate with the BMS 100 wirelessly or by wire, and may communicate with the server (not shown) wirelessly through the network. Therefore, the communication unit 210 of the upper controller 200 may include a wired communication unit and a wireless communication unit. Here, the wireless communication using the network may use various methods, including 3G, 4G, 5G, the Third Generation Partnership Project (3GPP), Long Term Evolution (LTE), Worldwide Interoperability for Microwave Access (WIMAX), Wi-Fi, Bluetooth communication, infrared communication, ultrasonic communication, visible light communication (VLC), etc.
[0069] (3)-2. Control unit
[0070] The control unit 220 generates a control command for controlling the plurality of BMSs 100. That is, the control unit 220 generates a control command to control operations such as charging and discharging and cell balancing of the battery 10 managed by the plurality of BMSs 100. In this case, the control unit 220 uses information about the battery 10 received from the plurality of BMSs 100, that is, state information such as voltage, current, and temperature of each of the battery cells, to generate a control command to control the battery 10 to an optimal state. The control command from the control unit 220 is transmitted to the plurality of BMSs 100 through the communication unit 210. In addition, the control unit 220 may store various information collected by each of the plurality of BMSs 100 on a server through a network. That is, for various research and development purposes, the control unit 220 may store various data collected by the BMS on a remote server or the like through a network by the communication unit 210. In this case, the various information collected by the plurality of BMSs 100 may be stored in a memory unit (not shown). Meanwhile, the control unit 220 of the present invention may transmit the battery cell information received from the BMS 100 and the number of battery cells whose information is stored to the authentication key information generation unit 230 and the first authentication key generation unit 240 through the communication unit 210 to generate the authentication key information and generate the first authentication key. That is, the control unit 220 may transmit the number of battery cells whose information is stored to the authentication key information generation unit 230 to generate the authentication key information, and transmit the battery cell information to the first authentication key generation unit 240 to generate the first authentication key.
[0071] (3)-3. Authentication key information generation unit
[0072] The authentication key information generation unit 230 generates predetermined authentication key information using the number value (N value) of the battery cells in which the information received from the BMS 100 is stored. That is, the authentication key information generation unit 230 receives the number value (N value) of the battery cells in which the information received through the communication unit 210 is stored through the control unit 220, and generates predetermined authentication key information. In this case, the authentication key information includes P and I, and P is a value that satisfies Any integer and I is satisfied Where N is the number of battery cells whose information is stored.
[0073] (3)-4. First authentication key generation unit
[0074] The first authentication key generation unit 240 generates a first authentication key using all battery cell information received from the BMS 100 and the authentication key information received from the authentication key information generation unit 230. In this case, the first authentication key generation unit 240 may generate the first authentication key using the received authentication key information, all battery cell voltages, the ID of the BMS, and the like. For example, the first authentication key generation unit 240 may generate the first authentication key in the following manner: generating a first battery cell voltage sum value by adding up the voltages of a predetermined number of battery cells selected from all battery cell information using the transmitted authentication key information, adding the ID of the BMS to the first battery cell voltage sum value, and then performing a crc16 hash operation. In this case, the first battery cell voltage sum value may be generated by adding up the voltages from the P+0th battery cell to the P+Ith battery cell from the battery cell information. Here, P is a value that satisfies Any integer, I is a Any integer of .
[0075] As described above, in the ESS according to one embodiment of the present invention, the upper controller 200 generates the authentication key information and the first authentication key using the battery cell information provided from the BMS 100, and when the authentication key information and the first authentication key are provided to the BMS 100, the BMS 100 generates the second authentication key using the authentication key information, and then determines the authenticity of the control command from the upper controller 200 by comparing the first authentication key and the second authentication key. In this case, when the BMS 100 provides the battery cell information to the upper controller 200, the BMS 100 stores the battery cell voltage information about any N battery cells among all the battery cells managed by the BMS 100 in the memory unit, and provides the battery cell voltage information to the upper controller 200, and the upper controller 200 generates the predetermined authentication key information using the number value of the battery cell whose information is stored. In addition, the upper controller 200 generates the first authentication key using the battery cell information and the predetermined authentication key information, and the BMS 100 generates the second authentication key using the number value of the cell whose information is stored and the received authentication key information. In this way, the authenticity of the control command from the upper controller 200 is determined by comparing the first authentication key and the second authentication key generated by the upper controller 200 and the BMS 100, respectively, so that secure communication between the BMS 100 and the upper controller 200 is possible. In addition, since secure communication can be performed with a small amount of operation, it is also possible to operate using a battery monitoring IC (BMIC).
[0076] 2. Communication method of energy storage system according to the present invention
[0077] Figure 4 is a flowchart for describing a communication method of an energy storage system according to an embodiment of the present invention.
[0078] refer to Figure 4 , a communication method according to an embodiment of the present invention may include: an operation S110 of transmitting battery cell information including voltage information about all battery cells from the BMS 100 to the upper controller 200; an operation S120 of storing voltage information about any N battery cells among all battery cells managed by the BMS 100; an operation S130 of transmitting the stored number N of battery cells to the upper controller 200; an operation S140 of generating authentication key information by the upper controller 200 using the value of the number N of battery cells whose information is stored; an operation S150 of generating a first authentication key using the battery cell information and the authentication key information; an operation S160 of transmitting the first authentication key and the authentication key information to the BMS 100; an operation S170 of generating a second authentication key by the BMS 100 using the number N of battery cells whose information is stored and the authentication key information; an operation S180 of determining whether the first authentication key and the second authentication key match by comparing the first authentication key with the second authentication key; and an operation S190 of determining the authenticity of a control command from the upper controller 200 according to a comparison result of the first authentication key and the second authentication key. In addition, the series of operations S110 to S190 may be repeated in a predetermined cycle. That is, the operation S110 for battery cell information transmission, the operation S120 for battery cell voltage information storage, the operation S130 for the transmission of the number of battery cells whose information is stored, the operation S140 for authentication key information generation, the operation S150 for first authentication key generation, the operation S160 for authentication key information and first authentication key transmission, the operation S170 for second authentication key generation, the operation S180 for first authentication key and second authentication key comparison, and the operation S190 for control command authenticity determination may be performed in a predetermined cycle. In addition, the above operations may be performed sequentially one by one on a plurality of BMSs 100 managed by the superior controller 200, the above operations may also be performed on at least two BMSs 100, and the above operations may be performed on all the plurality of BMSs 100. The secure communication method of the ESS between the BMS 100 and the superior controller 200 according to one embodiment of the present invention will be described in more detail for each of the operations as follows.
[0079] S110: Information about the battery 10 managed by at least one BMS 100 among the plurality of BMSs 100 is transmitted from the corresponding BMS 100 to the upper controller 200. In this case, the information about the battery 10 may include information about a plurality of battery cells managed by the corresponding BMS 100. In addition, the battery cell information may include battery cell voltages sensed by the sensing unit 110 for sensing the battery 10. That is, at least one BMS 100 among the plurality of BMSs 100 transmits battery cell information including voltage information about all battery cells to the upper controller 200. In this case, the battery cell information sensed by the sensing unit 210 may be transmitted to the communication unit 140 through the control unit 120, and may be transmitted to the upper controller 200 through the communication unit 140.
[0080] The BMS 100 may determine the number N of cells to transmit cell voltage information among a plurality of battery cells, and transmit voltage information about the N battery cells to the upper controller 200 .
[0081] The battery cell information may be transmitted to the upper controller 200 at a predetermined period, and the upper controller 200 may update the authentication key according to the predetermined period of receiving the cell information.
[0082] S120: After transmitting the battery cell information to the upper controller 200, the BMS 100 stores voltage information about any N battery cells among the plurality of battery cells managed by the BMS 100. That is, the BMS 100 stores voltage information about any number (i.e., N) of battery cells among the plurality of battery cells in the memory unit 150. This is for use in generating a second authentication key, which will be described below. In this case, the number of battery cells may be less than the total number of battery cells. Of course, the number of battery cells may be equal to the total number of battery cells.
[0083] In this case, the N value (which is the number of battery cells whose information is stored) can be arbitrarily determined by the BMS, and this allows the battery cell information to be selectively stored with a data size matching the capacity of the memory device owned by the BMS. That is, in the present invention, the BMS can determine the number of battery cells about which information is stored by considering the calculation amount of the BMS.
[0084] Furthermore, in the present invention, the cell voltage is used as the battery cell information, and the cell voltage is data used in all BMSs, has commonality, and has high resolution (generally in units of 0.0001V), and thus the probability of data duplication is low.
[0085] S130: Transmitting the number N of battery cells stored in the memory unit 150 to the upper controller 200. That is, the number N of battery cells about which voltage information is stored in the memory unit 150 is transmitted to the upper controller 200. To this end, the control unit 120 may transmit the number N of battery cells stored in the memory unit 150 to the upper controller 200 through the communication unit 140.
[0086] S140: The upper controller 200 generates authentication key information using the value of the number N of battery cells about which the cell voltage information is stored, which has been received from the BMS 100. That is, the communication unit 210 of the upper controller 200 communicates with the communication unit 140 of the BMS 100 to receive the number value N of the battery cells about which the cell voltage information is stored in the BMS 100, and the control unit 220 transmits the received value to the authentication key information generation unit 230. The authentication key information generation unit 230 generates the authentication key information including the value of the number N of battery cells about which the cell voltage information is stored. Any integer P and satisfying The authentication key information of any integer I.
[0087] S150: Generate a first authentication key using battery cell information and authentication key information. That is, the first authentication key generation unit 240 generates a first authentication key using all battery cell information received from the BMS 100 and the authentication key information received from the authentication key information generation unit 230. In this case, the first authentication key generation unit 240 may generate a first authentication key using the received authentication key information, all battery cell voltages, the ID of the BMS, and the like. For example, the first authentication key generation unit 240 may generate a first authentication key in the following manner: generate a first battery cell voltage sum value by adding up the voltages of a predetermined number of battery cells selected from all battery cell information using the transmitted authentication key information, add the ID of the BMS to the first battery cell voltage sum value, and then perform a crc16 hash operation. In this case, the first battery cell voltage sum value may be generated by adding up the voltages from the P+0th battery cell to the P+Ith battery cell from the battery cell information. Here, P is a condition that satisfies Any integer, I is a Any integer of .
[0088] Meanwhile, the first authentication key is regenerated or updated at each cycle consistent with a transmission cycle of the battery cell information from the BMS 100 to the upper controller 200 .
[0089] S160: The upper controller 200 transmits the first authentication key and the authentication key information to the BMS 100. That is, the control unit 220 receives the authentication key information from the authentication key information generation unit 230, receives the first authentication key from the first authentication key generation unit 240, and transmits the first authentication key to the BMS 100 through the communication unit 210.
[0090] S170: The BMS 100 generates a second authentication key using the number N of battery cells about which battery cell information is stored and the received authentication key information. That is, the second authentication key generation unit 160 generates a second authentication key using any battery cell information stored in the memory unit 150 and the authentication key information received from the upper controller 200 through the communication unit 140. In this case, the authentication key generation unit 160 may generate a second authentication key using the received authentication key information, a predetermined number of battery cell voltages, the ID of the BMS itself, and the like. For example, the authentication key generation unit 160 may generate a second authentication key in the following manner: a second cell voltage sum value is generated by adding up the voltages of a predetermined number of battery cells selected from any battery cell information using the received authentication key information, adding the ID of the BMS to the second cell voltage sum value, and then performing a crc16 hash operation. In this case, the second cell voltage sum value may be generated by adding up the voltages from the P+0th battery cell to the P+Ith battery cell from the battery cell information. Here, P is a cell voltage sum value satisfying Any integer, I is a is an arbitrary integer, and N is the number of battery cells whose information is stored.
[0091] Therefore, since the authentication key of the present invention does not simply use the cell voltage value to generate the authentication key, but uses the sum value of the cell voltage and includes the ID of the BMS therein, the BMS that has received the control command can accurately distinguish the control command with itself as the recipient, thereby improving security compared to using the cell voltage value as ordinary data because they are used to generate the authentication key. In addition, when the BMS confirms the control command later, it is only necessary to perform P+1 additions and one hash operation without decrypting the entire data, and thus the amount of calculation is reduced compared to the encryption / decryption method in the related art.
[0092] S180: Compare the first authentication key and the second authentication key with each other to determine whether the first authentication key and the second authentication key match. That is, the authentication key comparison unit 170 determines whether the first authentication key and the second authentication key are the same by comparing the second authentication key generated in the second authentication key generation unit 160 with the first authentication key generated from the upper controller 200. In this case, the authentication key comparison unit 170 may transmit different signals to the control unit 120 according to the comparison result of the first authentication key and the second authentication key. For example, when the first authentication key and the second authentication key are the same, a logic high signal may be transmitted to the control unit 120, and when the first authentication key and the second authentication key are not the same, a logic low signal may be transmitted to the control unit 120.
[0093] S190: Determine the authenticity of the control command from the upper controller 200 according to the comparison result of the first authentication key and the second authentication key. The determination result of the authentication key comparison unit 170 is transmitted to the control unit 120, and according to the determination result of the authentication key comparison unit 170, when the first authentication key and the second authentication key are the same, the control unit 120 executes the control command received from the upper controller 200, and when the first authentication key and the second authentication key are not the same, the control unit 120 ignores the control command received from the upper controller 200.
[0094] <Example>
[0095] When the number of cells connected to the BMS having ID 3 is 5 and the cell voltages are as follows, an embodiment of authentication key generation in the present invention will be described.
[0096] The voltage value of each monomer (unit is 0.0001V):
[0097] Monomer 1: 31234 Monomer 2: 32345
[0098] Monomer 3: 33456 Monomer 4: 35678
[0099] Monomer 5: 37890
[0100] The BMS determines a predetermined value of N. In the present embodiment, N=4, and therefore, the BMS stores data of cells 1 to 4 in a BMS memory and transmits all cell data to an upper controller.
[0101] The upper controller determines predetermined P and I values (P: 2, I: 3 in this embodiment), and calculates a value (101479+3=101482) obtained by adding the BMS ID to the sum of the first cell voltages (cell 2+cell 3+cell 4) according to the received data.
[0102] The upper controller then generates a value obtained by performing a hash operation on a value obtained by adding the BMS ID and the sum of the first cell voltages as a first authentication key, and the BMS also generates a second authentication key in this manner, and determines the authenticity of the control command from the upper controller by comparing the received first authentication key with the generated second authentication key.
[0103] Meanwhile, although the technical spirit of the present invention as described above has been specifically described according to the above embodiments, it should be noted that the above embodiments are for explanation rather than limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical spirit of the present invention.
[0104] The names of the reference numerals used in the present invention are as follows.
[0105] 10: Battery 100: BMS
[0106] 200: upper controller 110: sensing unit
[0107] 120: control unit 130: switch unit
[0108] 140: Communication unit 150: Memory unit
[0109] 160: Second authentication key generation unit 170: Authentication key comparison unit
[0110] 210: Communication unit 220: Control unit
[0111] 230: Authentication key information generation unit 240: First authentication key generation unit.
Claims
1. An energy storage system, comprising: Multiple BMSs, each BMS manages multiple battery cells; as well as an upper level controller, wherein the upper level controller transmits a predetermined control command to the plurality of BMSs, wherein the upper controller generates authentication key information and a first authentication key using battery cell information provided from the BMS, and The BMS receives the authentication key information and the first authentication key from the upper controller, generates a second authentication key using the authentication key information, and then determines the authenticity of a control command from the upper controller by comparing the first authentication key and the second authentication key.
2. The energy storage system according to claim 1, wherein: The BMS determines the number N of battery cells to transmit battery cell information and the battery cell information among all battery cells managed by the BMS, and provides battery cell voltage information of the determined N battery cells to the upper controller, The upper controller generates the authentication key information using the determined value of the number N of battery cells, and then generates the first authentication key using the battery cell information and the authentication key information, and The BMS generates the second authentication key using the determined number N of battery cells and the received authentication key information.
3. The energy storage system according to claim 2, wherein: The upper controller comprises: a communication unit that receives voltage information about the N battery cells controlled by at least one BMS among the plurality of BMSs and transmits the generated authentication key information and the first authentication key to the BMS; an authentication key information generating unit, the authentication key information generating unit generating the authentication key information according to the number N of the battery cells and the received battery cell information; and A first authentication key generation unit is configured to generate the first authentication key using the battery cell information and the authentication key information.
4. The energy storage system according to claim 3, wherein: The authentication key information generation unit generates the authentication key information, and the authentication key information includes Any integer P and satisfying Any integer I.
5. The energy storage system according to claim 3, wherein: The first authentication key generation unit generates the first authentication key by generating a first battery cell voltage sum value by adding voltages of a predetermined number of battery cells selected from all battery cell information using the authentication key information, adding the ID of the BMS to the first battery cell voltage sum value, and then performing a hash operation.
6. The energy storage system according to claim 5, wherein: The first battery cell voltage sum value is generated by adding the voltages from the P+0th battery cell to the P+1th battery cell from the battery cell information, where P is a voltage that satisfies Any integer, I is a is an arbitrary integer, and N is the number of battery cells about which cell information is stored.
7. The energy storage system according to claim 2, wherein: The BMS includes: a memory unit storing voltage information about any N battery cells among all battery cells managed by the BMS; a communication unit that transmits to the upper controller a value of the number N of the battery cells about which battery cell information including voltage information about all battery cells managed by the BMS is stored, and receives the authentication key information and the first authentication key from the upper controller; a second authentication key generating unit that generates a second authentication key using the authentication key information and a value of the number N of battery cells whose voltage information is stored; an authentication key comparison unit, the authentication key comparison unit comparing the first authentication key and the second authentication key; and A control unit is configured to determine the authenticity of the control command from the upper controller based on a comparison result of the authentication key comparison unit.
8. The energy storage system according to claim 7, wherein: The second authentication key generation unit generates the second authentication key by generating a second cell voltage sum value by adding voltages of a predetermined number of battery cells selected from arbitrary battery cell information using the authentication key information, adding the ID of the BMS to the second cell voltage sum value, and then performing a hash operation.
9. The energy storage system according to claim 8, wherein: The second cell voltage sum value is generated by adding the voltages from the P+0th cell to the P+1th cell from the cell information, where P is a cell voltage that satisfies Any integer, I is a is an arbitrary integer, and N is the number of battery cells whose battery cell information is stored.
10. A communication method for an energy storage system, the communication method comprising: Receiving battery cell information including battery cell voltage information from the BMS by the upper controller; The upper controller uses the battery cell information to generate authentication key information and a first authentication key; The BMS receives the authentication key information from the upper controller to generate a second authentication key and compares the second authentication key with the first authentication key; as well as The BMS executes a control command from the upper controller according to a comparison result between the first authentication key and the second authentication key.
11. The communication method according to claim 10, wherein: The authentication key information includes Any integer P and satisfying Any integer I.
12. The communication method according to claim 10, wherein: The first authentication key is generated by generating a first cell voltage sum value by adding voltages of a predetermined number of cells selected from all cell information using the authentication key information, adding the ID of the BMS to the first cell voltage sum value, and then performing a hash operation.
13. The communication method according to claim 12, wherein: The first battery cell voltage sum value is generated by adding the voltages from the P+0th battery cell to the P+1th battery cell from the battery cell information, where P is a voltage that satisfies Any integer, I is a is an arbitrary integer, and N is the number of battery cells whose battery cell information is stored.
14. The communication method according to claim 10, wherein: The second authentication key is generated by generating a second cell voltage sum value by adding voltages of a predetermined number of battery cells selected from arbitrary battery cell information using the authentication key information, adding the ID of the BMS to the second cell voltage sum value, and then performing a hash operation.
15. The communication method according to claim 14, wherein: The second cell voltage sum value is generated by adding the voltages from the P+0th cell to the P+1th cell from the cell information, where P is a cell voltage that satisfies Any integer, I is a is an arbitrary integer, and N is the number of battery cells about which cell information is stored.
16. A communication method for an energy storage system, the communication method comprising: transmitting battery cell information including voltage information about all battery cells from the BMS to a superior controller; storing voltage information about any N battery cells among all battery cells managed by the BMS; Transmitting the number N of stored battery cells to the upper controller; generating, by the upper controller, authentication key information using a value of the number N of the battery cells about which the voltage information is stored; generating a first authentication key using the battery cell information and the authentication key information; transmitting the first authentication key and the authentication key information to the BMS; generating, by the BMS, a second authentication key using the number N of the battery cells about which the voltage information is stored and the authentication key information; as well as The authenticity of the control command from the superior controller is determined by comparing the first authentication key with the second authentication key.