Energy storage system and its communication method

Abstract

The present invention provides an energy storage system and its communication method, including a process of transmitting battery cell information including the voltage information of the entire battery cells from a battery management system (BMS) to a host controller, a process of storing voltage information regarding any N battery cells among the plurality of battery cells managed by the battery management system (BMS), a process of transmitting the number of the stored N battery cells to the host controller, a process of the host controller generating authentication key information using the number value of the N battery cells in which the voltage information is stored, a process of generating a first authentication key using the battery cell information and the authentication key information, a process of transmitting the first authentication key and the authentication key information to the battery management system (BMS), a process of the battery management system (BMS) generating a second authentication key using the number of the N battery cells in which the voltage information is stored and the authentication key information, and a process of comparing the first authentication key and the second authentication key to determine the authenticity of a control command from the host controller.

Description

Technical Field

[0001] The present invention relates to an energy storage system (ESS: Energy Storage System), and more particularly, to an energy storage system capable of secure communication and a communication method thereof.

Background Art

[0002] With environmental destruction, resource depletion, etc. being regarded as problems, interest in systems that can store electricity and efficiently utilize the stored electricity has been increasing. Also, in conjunction with this, interest in renewable energy that does not cause pollution in the power generation process has been increasing. An energy storage system (Energy Storage System; ESS) is a system that combines such renewable energy, batteries storing electricity, and existing grid power, and a lot of research and development is being actively conducted in line with today's environmental changes. That is, an ESS is a device that stores the generated electricity in a storage device such as a battery and supplies it when power is needed to improve the power usage efficiency. Therefore, an ESS includes a battery for storing electricity and equipment for efficiently managing and controlling the battery.

[0003] An ESS may include a plurality of batteries for storing power, but an ESS may also include at least one battery bank. Also, each of the battery banks may include a plurality of battery racks, and each of the plurality of battery racks may include a plurality of battery modules. And each of the battery modules includes a plurality of battery cells. That is, a plurality of battery cells are bundled to form one battery module, a plurality of battery modules are bundled to form one battery rack, a plurality of battery racks are bundled to form one battery bank, and an ESS may be constituted by at least one battery bank.

[0004] For such an ESS (Energy Storage System), it is crucial to efficiently manage a wide range of aspects, including battery charging, discharging, and cell balancing. Efficient battery management extends battery life and ensures a stable power supply to the load. For this purpose, an ESS may be equipped with a Battery Management System (BMS). The BMS monitors the battery's voltage, current, temperature, and other conditions to maintain it in an optimal state. The BMS also manages the battery system, including the battery and its peripheral devices, by predicting when batteries need replacing and proactively identifying battery problems. Such a BMS may be provided in each of the battery banks, battery racks, and battery modules. That is, each of the battery bank, battery rack, and battery module may have a Bank BMS (BBMS), Rack BMS (RBMS), and Module BMS (MBMS), respectively. The ESS also includes a Battery System Controller (BSC), which is the highest-level controller that controls the entire ESS. Therefore, the ESS forms a hierarchical battery management system connected to the BSC-BBMS-RBMS-MBMS. For example, control commands from the BSC are passed to the BBMS, RBMS, and MBMS to manage the batteries.

[0005] On the other hand, for various research and development purposes, the BMS can also store various data it collects on a remote central server. In other words, ESSs are increasingly exposing controllers for battery control, such as BSCs, to the public internet for remote control and remote monitoring. However, when controllers are exposed, they have security vulnerabilities that make them vulnerable to malware infections and attacks from hackers. Furthermore, given the nature of ESSs that handle enormous amounts of electrical energy, there is a possibility that threats from hackers or arbitrary control could cause significant physical damage. These problems can be prevented by applying encryption methods to communication between the controller and the lower-level BMS. However, encrypting the entire communication requires a great deal of computing power, which is a heavy burden for battery monitoring ICs (BMICs), which use relatively lower computing power compared to personal computers (PCs).

[0006] In this regard, Patent Document 1 presents a battery pack equipped with a wireless communication module and discloses a technology for generating an authentication number for the battery pack and authenticating the battery pack with connected external electronic devices, while Patent Document 2 discloses a battery system that performs mutual authentication between a master BMS and a slave BMS using an authentication key.

[0007] Furthermore, Patent Document 3 discloses a battery management system that generates an authentication code and transmits battery measurement data along with the authentication code when transmitting data packets to an external device, and Patent Document 4 discloses a method for generating a secret key that generates a primary secret key using the voltage measured in the battery and transmits it to an external device, receives a secondary secret key generated by the external device using the primary secret key, and generates a final secret key by performing calculations using the primary and secondary secret keys.

[0008] However, the aforementioned conventional patent documents fail to provide a method for verifying the authenticity of control commands by checking an authentication key when transmitting control commands between a battery management device and a higher-level controller. Furthermore, generating an authentication key and encrypting the data encrypts the entire data, which leads to the problem of not being able to use computing resources efficiently.

[0009] Conventional technologies are as follows: [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Republic of Korea Publication Patent No. 10-2018-0056460 [Patent Document 2] Republic of Korea Publication Patent No. 10-2014-0019629 [Patent Document 3] Republic of Korea Publication Patent No. 10-2021-0051462 [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] This invention provides an energy storage system and a communication method that enable secure communication between a controller and a lower-level BMS.

[0012] The present invention provides an energy storage system and a communication method thereof that determines the authenticity of a control command from a controller by generating first and second authentication keys in the controller and the lower BMS, respectively, and comparing them.

[0013] Furthermore, the present invention provides a method for generating an authentication key using computing resources efficiently and for communication between a BMS and a controller using this key. [Means for solving the problem]

[0014] An energy storage system according to an embodiment of the present invention includes a plurality of BMSs that respectively manage a plurality of battery cells, and a host controller that transmits a predetermined control command to the plurality of BMSs. The host controller generates authentication key information and a first authentication key using the battery cell information provided from the BMSs. After the BMSs generate a second authentication key using the authentication key information from the host controller, the BMSs compare the first and second authentication keys to determine the authenticity of the control command from the host controller.

[0015] The BMS provides the host controller with battery cell voltage information regarding any N battery cells among all the battery cells managed by the BMS together with the battery cell information. After the host controller generates the authentication key information using the number value (N) of the battery cells in which the information is stored, the host controller generates a first authentication key using the battery cell information and the authentication key information. The BMS generates a second authentication key using the number value (N) of the battery cells in which the information is stored and the received authentication key information.

[0016] The host controller includes a communication unit that receives battery cell information including voltage information of all the battery cells controlled by at least one of the plurality of BMSs and voltage information of any N battery cells, and transmits authentication key information and a first authentication key to the BMSs, an authentication key information generation unit that generates authentication key information from the number value (N) of the battery cells in which the 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.

[0017] The authentication key information generation unit generates the authentication key information including an arbitrary integer P satisfying 0 < P ≤ N and an arbitrary integer I satisfying 0 < P+(I + 1) ≤ N.

[0018] The first authentication key generation unit calculates the sum of the voltages of a predetermined number of battery cells selected from the overall battery cell information using the authentication key information to generate a first battery cell voltage sum value, adds the ID of the BMS to the first battery cell voltage sum value, and then performs a crc16 hash operation to generate a first authentication key.

[0019] The first battery cell voltage sum value is generated by calculating the sum of the voltages from the P+0th battery cell to the P+Ith battery cell from the battery cell information. Here, P is an arbitrary integer satisfying 0<P≦_N, I is an arbitrary integer satisfying 0<P+(I+1)≦_N, and N is the number value of the battery cells in which the cell information is stored.

[0020] The BMS includes a memory unit that stores the voltage information of any N battery cells among all the battery cells managed by the BMS, a communication unit that transmits the battery cell information including the voltage information of all the battery cells managed by the BMS and the number value (N) of the battery cells in which the voltage information is stored to the upper controller, and receives authentication key information and a first authentication key from the upper controller, a second authentication key generation unit that generates a second authentication key from the authentication key information and the number value (N) of any battery cells in which the voltage information is stored, an authentication key comparison unit that compares the first and second authentication keys, and a control unit that determines the authenticity of the control command from the upper controller based on the comparison result of the authentication key comparison unit.

[0021] [[ID=V11]] The second authentication key generation unit calculates the sum of the voltages of a predetermined number of battery cells selected from arbitrary battery cell information using the authentication key information to generate a second cell voltage sum value, adds the ID of the BMS to the second cell voltage sum value, and then performs a crc16 hash operation to generate a second authentication key.

[0022] The second cell voltage sum value is generated by summing the voltages of the battery cells from the (P + 0)-th battery cell to the (P + I)-th battery cell from the battery cell information. Here, P is an arbitrary integer satisfying 0 < P ≤ _N, I is an arbitrary integer satisfying 0 < P + (I + 1) ≤ _N, and N is the number value of the battery cells in which the information is stored.

[0023] The communication method of the energy storage system according to another embodiment of the present invention includes a process in which a host controller receives from a BMS the provision of battery cell information including battery cell information and arbitrary battery cell voltage information, a process in which the host controller generates authentication key information and a first authentication key using the battery cell information and the arbitrary battery cell voltage information, a process in which the BMS receives the provision of the authentication key information from the host controller, generates a second authentication key, and compares it with the first authentication key, and a process in which the BMS executes a control command from the host controller based on the comparison result of the first and second authentication keys.

[0024] The authentication key information includes an arbitrary integer P satisfying 0 < P ≤ _N and an arbitrary integer I satisfying 0 < P + (I + 1) ≤ _N.

[0025] The first authentication key is generated by summing the voltages of a predetermined number of battery cells selected from the entire battery cell information using the authentication key information to generate a first battery cell voltage sum value, adding the ID of the BMS to the first battery cell voltage sum value, and then performing a crc16 hash operation.

[0026] The first battery cell voltage sum value is generated by summing the voltages of the battery cells from the (P + 0)-th battery cell to the (P + I)-th battery cell from the battery cell information. Here, P is an arbitrary integer satisfying 0 < P ≤ _N, I is an arbitrary integer satisfying 0 < P + (I + 1) ≤ _N, and N is the number value of the battery cells in which the information is stored.

[0027] The second authentication key is generated by adding up the voltages of a predetermined number of battery cells selected from any battery cell information using the authentication key information to generate a second combined cell voltage value, adding the ID of the BMS to the second combined cell voltage value, and then performing a crc16 hash operation.

[0028] The second combined cell voltage value is generated by adding up the voltages from the (P + 0)-th battery cell to the (P + I)-th battery cell from the battery cell information. Here, P is an arbitrary integer satisfying 0 < P ≤ N, I is an arbitrary integer satisfying 0 < P + (I + 1) ≤ N, and N is the number value of the battery cells in which the information is stored.

[0029] A communication method of an energy storage system according to still another embodiment of the present invention includes a process of transmitting battery cell information including voltage information of all battery cells from the BMS to a host controller, a process of storing voltage information regarding any N battery cells among the plurality of battery cells managed by the BMS, a process of transmitting the number of the stored N battery cells to the host controller, a process of the host controller generating authentication key information using the number value of the N battery cells in which the voltage information is stored, a process of generating a first authentication key using the battery cell information and the authentication key information, a process of transmitting the first authentication key and the authentication key information to the BMS, a process of the BMS generating a second authentication key using the number of the N battery cells in which the voltage information is stored and the authentication key information, and a process of comparing the first authentication key and the second authentication key to determine the authenticity of a control command from the host controller.

Advantages of the Invention

[0030] In this invention, a higher-level controller generates authentication key information and a first authentication key using battery cell information provided by the BMS, and provides the authentication key information and the first authentication key to the BMS. The BMS then generates a second authentication key using the authentication key information, and then compares the first and second authentication keys to determine the truth or falsity of the control command from the higher-level controller. At this time, when the BMS provides battery cell information to the higher-level controller, it stores battery cell voltage information for any N battery cells out of the total number of battery cells managed by the BMS in its memory and provides this to the higher-level controller. The higher-level controller generates predetermined authentication key information using the numerical values ​​of the battery cells in which the information is stored. The higher-level controller also 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 numerical values ​​of the battery cells in which the information is stored and the received authentication key information.

[0031] As mentioned above, secure communication between the BMS and the controller is possible by comparing the first and second authentication keys generated in the higher-level controller and the lower-level BMS, respectively, to determine the authenticity of the control command from the controller. Furthermore, since secure communication is possible with minimal computation, it can be performed even using a Battery Monitoring IC (BMIC). [Brief explanation of the drawing]

[0032] [Figure 1] This is a block diagram illustrating the configuration of an energy storage system according to one embodiment of the present invention. [Figure 2] This is a block diagram illustrating the configuration of a battery management system (BMS) that constitutes an energy storage system according to one embodiment of the present invention. [Figure 3] This is a block diagram illustrating the configuration of a higher-level controller constituting an energy storage system according to one embodiment of the present invention. [Figure 4] This is a flowchart illustrating a communication method for an energy storage system according to one embodiment of the present invention. [Modes for carrying out the invention]

[0033] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. However, the present invention is not limited in any way to the embodiments disclosed below and can be embodied in a variety of different forms, and these embodiments are provided merely to complete the disclosure of the present invention and to fully inform those in the ordinary skill of the scope of the invention.

[0034] 1. Energy storage system for authentication key communication according to the present invention Figure 1 is a block diagram illustrating the configuration of an energy storage system according to one embodiment of the present invention, Figure 2 is a block diagram illustrating the configuration of a BMS constituting an energy storage system according to one embodiment of the present invention, and Figure 3 is a block diagram illustrating the configuration of a higher-level controller constituting an energy storage system according to one embodiment of the present invention.

[0035] Referring to Figure 1, an energy storage system according to one embodiment of the present invention may include a plurality of BMS 100a, 100b, ..., 100n; 100 for managing the battery 10, and a higher-level controller 200 for controlling the battery 10 via the plurality of BMS 100. The higher-level controller 200 can be connected to a server or the like via a network, but the network may be the public internet such as a cloud service. In such an energy storage system, the BMS 100 provides information about the battery 10 to the higher-level controller 200 and receives control commands from the higher-level controller 200 for controlling the battery 10.

[0036] Furthermore, in the energy storage system according to the present invention, the higher-level controller 200 generates a first authentication key and authentication key information using battery cell information provided by the BMS 100 and provides them to the BMS 100. The BMS 100 generates a second authentication key using the authentication key information, and then compares the first and second authentication keys to determine the truth or falsity of the control command from the higher-level controller 200. At this time, if the first and second authentication keys are the same, it is determined that the control command was transmitted from the higher-level controller 200, and if the first and second authentication keys are not the same, it is determined that the control command is false. A more detailed description of each component of such an energy storage system according to one embodiment of the present invention is as follows.

[0037] (1) Battery The battery 10 is rechargeable by receiving power and can discharge the charged electrical energy to supply power to a power consumption device. In other words, the battery 10 is rechargeable and can be used as an energy source for a power consumption device. Here, the battery 10 may comprise a plurality of battery cells. Needless to say, the battery 10 may be a battery module, a battery rack, or a battery bank. That is, if the BMS 100 of the present invention is a module BMS, the battery 10 may be a battery module; if the BMS 100 is a rack BMS, the battery 10 may be a battery rack; or if the BMS 100 is a bank BMS, the battery 10 may be a battery bank. Therefore, the battery 10 may be a battery module in which a plurality of battery cells are bundled together; a battery rack in which a plurality of battery modules are bundled together; or a battery bank in which a plurality of battery racks are bundled together. On the other hand, the plurality of battery cells, which are the basic components constituting the battery 10, can be connected in series and / or parallel in various ways. Needless to say, multiple battery modules, each comprising multiple battery cells, can also be connected in series and / or parallel. Here, the battery cells may be lithium-ion batteries. However, the battery cells may consist not only of lithium-ion batteries, but also of lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and the like.

[0038] (2)BMS(Battery Management System) The BMS100 estimates the state of the battery 10 and manages the battery 10 using the estimated state information. For example, the BMS100 measures the state of the battery 10, such as voltage, current, and temperature, and uses this state information to estimate the battery's State of Charge (SOC), State of Health (SOH), and State of Power (SOP). SOC indicates the remaining capacity of the battery, and accurate prediction of SOC allows for prediction of future driving distance. SOH indicates the battery's capacity, which signifies the battery's aging state and affects the number of charge and discharge cycles. SOP represents the maximum power the battery can provide. Predicting maximum power helps prevent battery overcharging and heat loss. Using this state information, the BMS100 controls the charging or discharging of the battery 10. To this end, the BMS 100 may include, as shown in Figure 2, a sensing unit 110 for sensing the state of the battery 10, a control unit 120 for generating control signals to control the charging and discharging of the battery 10 according to the state of the battery 10 measured by the sensing unit 110, and a switching unit 130 for switching the connection between the battery 10 and an external power supply or power consumption device based on the control signals of the control unit 120 to enable charging and discharging. Furthermore, the BMS 100 according to one embodiment of the present invention transmits battery cell information to a higher-level controller 200 and stores information on at least one arbitrarily selected, i.e., N battery cells. The BMS 100 then receives a first authentication key and authentication key information from the higher-level controller 200 and generates an authentication key by combining the stored battery cell information and the received authentication key information. Furthermore, the BMS 100 compares the generated second authentication key with the received first authentication key, and if they are the same, it carries out the command received from the higher-level controller 200; otherwise, it ignores the command received from the higher-level controller 200.For this purpose, the BMS 100 according to one embodiment of the present invention may include a communication unit 140 for communication with a higher-level 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 and second authentication keys. In this case, the control unit 120 determines the truth or falsity of the control command based on the comparison result of the authentication key comparison unit 170. That is, if the first and second authentication keys are the same as a result of the comparison by the authentication key comparison unit 170, the control unit 120 executes the control command from the higher-level controller 200; if they are not the same, the control unit 120 determines that the control command is false and ignores the control command. Furthermore, the control unit 120 can not only control the switching unit 130 for charging and discharging the battery 10, but also control each component of the BMS 100. In other words, the control unit 120 can control the communication unit 140 to provide battery cell information to the higher-level controller 200, can store the battery cell information in the memory unit 150, and can execute control commands from the higher-level controller 200 based on 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 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 for the generation and comparison of authentication keys. In short, the Energy Storage System (ESS) for security communication of the present invention may have a BMS 100 comprising the control unit 120, the communication unit 140, the memory unit 150, the second authentication key generation unit 160 and the authentication key comparison unit 170.

[0039] On the other hand, the BMS 100 may be a plurality of module BMSs (MBMSs) for managing a predetermined number of battery modules, a plurality of rack BMSs (RBMSs) for managing a predetermined number of module BMSs (MBMSs), or at least one bank MBS (BBMS) for managing a predetermined number of rack BMSs (RBMSs). In other words, the present invention allows at least one of the module BMS, rack BMS, and bank BMS to generate an authentication key via communication with the higher-level controller 200 and to compare it to determine the authenticity of a control command from the higher-level controller 200.

[0040] A more detailed explanation of each component of the BMS100 according to this embodiment of the present invention is as follows.

[0041] (2)-1. Sensing Unit The sensing unit 110 may be provided to sense the state of the battery 10. For example, the sensing unit 110 can sense the current, voltage, temperature, etc., of the battery 10. The sensing unit 100 can also sense the state of the battery module and battery cells, such as the current and voltage. That is, it can sense the state of each of multiple battery cells, or it can sense the state of a battery module in which multiple battery cells are bundled together. For this purpose, the sensing unit 110 may be equipped with multiple sensors. That is, it may be equipped with at least one current sensor, at least one voltage sensor, and at least one temperature sensor. The voltage sensor, current sensor, and temperature sensor periodically measure the voltage, current, and temperature of the battery 10 according to 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. The current sensor is a sense resistor or a Hall sensor and generates a signal corresponding to the magnitude of the charging current and provides it to the control unit 120. The current sensor can measure not only the charging current but also the magnitude of the discharge current. The temperature sensor may be, for example, a thermocoupler used for measuring temperature. The temperature sensor generates a signal corresponding to the temperature of the battery 10 and provides it to the control unit 120.

[0042] (2)-2. Control Unit The control unit 120 can control the battery 10 according to the state of the battery 10 measured by the sensing unit 110. Specifically, the control unit 120 can perform various functions such as battery life management, battery capacity control, and battery balancing. Furthermore, the control unit 120 can control the charging and discharging of the battery 10 by generating a control signal based on the voltage measured by the sensing unit 110 and controlling the switching unit 130 between the battery 10 and the external power supply, thereby preventing overcharging or over-discharging of the battery cells. For example, the control unit 120 can 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. If the measured voltage is higher than or equal to the first set voltage, it can generate a control signal to stop the charging operation of the battery 10. If the measured voltage is lower than or equal to the second set voltage, it can generate a control signal for charging the battery 10. Furthermore, the control unit 120 can provide battery cell information to the higher-level controller 200, perform operations in response to control commands from the higher-level controller 200, and control the communication unit 140 for this purpose. That is, the control unit 120 can transmit battery cell information to the higher-level controller 200 via the communication unit 140, and can receive control commands from the higher-level controller 200 via the communication unit 140. The control unit 120 then selects at least one battery cell information from the total battery cell information, i.e., N battery cell information, and stores it in the memory unit 150, and transmits the number of battery cells (N) in which the battery cell information is stored to the higher-level controller 200. At this time, the battery cell information may include the voltage of the battery cell. Moreover, the control unit 120 can determine the truth or falsity of a control command based on the comparison result of the authentication key comparison unit 170, which compares a first authentication key from the higher-level controller 200 with a second authentication key from the second authentication key generation unit 160, and execute the control command from the higher-level controller 200.

[0043] (2)-3. Switching section The switching unit 130 may be provided to control the flow of current related to charging or discharging the battery 10. That is, the switching unit 130 can be provided on the charging and discharging path to set the charging and discharging path. In this case, the switching unit 130 can perform charging or discharging based on the control signal of the control unit 120. Such a switching unit 130 may consist of semiconductor switching elements for controlling the flow of current related to charging or discharging. For example, depending on the specifications of the battery 10, at least one field-effect transistor (FET), a relay, etc., can be used. Specifically, the switching unit 130 may consist of a charging switch and a discharging switch, respectively, which are driven based on the control signal of the control unit 120. In this case, the charging and discharging switches may each consist of FETs.

[0044] (2)-4. Communications Department The communication unit 140 may be provided for communication between the BMS 100 and the higher-level controller 200. That is, the communication unit 140 may be provided to transmit battery cell information from the BMS 100 to the higher-level controller 200 and to receive control commands from the higher-level controller 200. The communication unit 140 can also receive a first authentication key and authentication key information from the higher-level controller 200. Control commands from the higher-level controller 200 received via the communication unit 140 can be passed on to the control unit 120, authentication key information from the higher-level controller 200 can be passed on to the authentication key generation unit 160, and the first authentication key from the higher-level controller 200 can be passed on to the authentication key comparison unit 170. Here, the communication unit 140 can communicate with the higher-level controller 200 by wire or wireless connection. For example, the communication unit 140 can communicate with the higher-level controller 200 using a Controller Area Network (CAN) or a Local Interconnect Network (LIN) method.

[0045] (2)-5. Memory section When transmitting battery cell information to the higher-level controller 200, the memory unit 150 stores voltage information for any N battery cells. In other words, the memory unit 150 can store information for any battery cells selected by the control unit 120 via the control unit 120. The memory unit 150 can also store information such as the unique ID of the BMS 100, and can store information about the unique characteristics of the battery 10 for purposes such as the charging and discharging operation of the battery 10. Such a memory unit 150 may include storage media such as random access memory (RAM), static random access memory (SRAM), ferroelectric random access memory (FRAM®) (Ferro-electric RAM), phase-change random access memory (PRAM), magnetic random access memory (MRAM), flash memory, electrically erasable programmable read-only memory (EEPROM), read-only memory (ROM), and programmable read-only memory (PROM).

[0046] (2)-6. Second authentication key generation unit The second authentication key generation unit 160 generates a second authentication key using arbitrary battery cell information stored in the memory unit 150 and authentication key information received from the upper controller 200 via the communication unit 140. At this time, the authentication key generation unit 160 can generate the second authentication key using the received authentication key information, a predetermined number of battery cell voltages, the ID of the BMS, etc. For example, the authentication key generation unit 160 uses the received authentication key information to sum the voltages of a predetermined number of battery cells selected from arbitrary battery cell information to generate a second cell voltage sum value, adds the ID of the BMS to the second cell voltage sum value, and then performs a crc16 hash operation to generate a second authentication key. At this time, the second cell voltage sum value can be generated by summing the voltages from the P+0th battery cell to the P+Ith battery cell from the battery cell information. Here, P is an arbitrary integer satisfying 0<P≦_N, I is an arbitrary integer satisfying 0<P+(I+1)≦_N, and N is the number of battery cells in which the information is stored.

[0047] (2)-7. Authentication key comparison unit The authentication key comparison unit 170 compares the second authentication key generated by the second authentication key generation unit 160 with the first authentication key generated by the upper controller 200. That is, the authentication key comparison unit 170 compares the first and second authentication keys and determines whether they are the same. The comparison result of the authentication key comparison unit 170 is transmitted to the control unit 120, and the control unit 120 executes the control command received from the upper controller 200 based on the comparison result of the authentication key comparison unit 170 when the first and second authentication keys are the same, and ignores the control command received from the upper controller 200 when they are not the same. At this time, the authentication key comparison unit 170 can deliver different signals to the control unit 120 based on the comparison result of the first and second authentication keys. For example, when the first and second authentication keys are the same, a logic high signal can be delivered to the control unit 120, and when they are not the same, a logic low signal can be delivered to the control unit 120.

[0048] (3) Upper controller The higher-level controller 200 may be provided for controlling the ESS. That is, the higher-level controller 200 may be provided for controlling multiple BMS 100s. The higher-level controller 200 can transmit control commands to the BMS 100 for controlling multiple batteries 10. As a result, the BMS 100's operation is controlled based on the control commands received from the higher-level controller 200, thereby controlling operations such as charging and discharging the batteries 10. Here, the higher-level controller 200 may be a Battery System Controller (BSC) for controlling the ESS. Furthermore, the higher-level controller 200 according to one embodiment of the present invention can generate authentication key information for secure communication with the BMS 100 and generate a first authentication key from it. To this end, the higher-level controller 200 periodically receives total battery cell information from multiple BMS 100s and receives the number of battery cell information currently stored in each BMS 100. The higher-level controller 200 then generates predetermined authentication key information using the individual values ​​(i.e., N values) of the battery cells in which the information is stored, and generates a first authentication key using the battery cell information and the authentication key information. The higher-level controller 200 also transmits the first authentication key and the authentication key information to the BMS 100.

[0049] (3)-1. Communications Department The communication unit 210 may be provided for communication between the higher-level controller 200 and the BMS 100. Alternatively, the communication unit 210 may be provided for communication between the higher-level controller 200 and a server via a network. That is, the communication unit 210 may be provided to receive battery cell information from the BMS 100 and transmit control commands from the higher-level controller 200 to the BMS 100. Furthermore, the communication unit 210 can transmit a first authentication key and authentication key information from the higher-level controller 200 to the BMS 100. Such a communication unit 210 can communicate with the BMS 100 via wired or wireless means; for example, the communication unit 210 can communicate with the BMS 100 using a Controller Area Network (CAN) or a Local Interconnect Network (LIN). On the other hand, the communication unit 210 can also communicate with a server (not shown) via a network; wireless communication can be used for network-based communication. In other words, the communication unit 210 can communicate with the BMS 100 wirelessly or via a wired connection, and with a server (not shown) wirelessly via a network. Therefore, the communication unit 210 of the higher-level controller 200 may comprise a wired communication unit and a wireless communication unit. Here, a wide variety of methods can be used for wireless communication using a network, including third generation (3G), fourth generation (4G), fifth generation (5G), 3rd Generation Partnership Project (3GPP®), Long Term Evolution (LTE), World Interoperability for Microwave Access (WIMAX), Wi-Fi, Bluetooth® communication, infrared communication, ultrasonic communication, and Visible Light Communication (VLC).

[0050] (3)-2. Control Unit The control unit 220 generates control commands for controlling a plurality of BMSs 100. That is, the control unit 220 generates control commands for controlling operations such as charging and discharging of the battery 10 managed by the plurality of BMSs 100 and cell balancing. At this time, the control unit 220 generates a control command for controlling the battery 10 to an optimal state using the information of the battery 10 received from the plurality of BMSs 100, that is, the state information such as the voltage, current, and temperature of each battery cell. The control command from the control unit 220 is delivered to the plurality of BMSs 100 via the communication unit 210. Further, the control unit 220 can store various information collected by the plurality of BMSs 100 in a server via a network. That is, the control unit 220 can also store various data collected by the BMS in a remote server or the like via the communication unit 210 and the network for various research and development. At this time, various information collected by the plurality of BMSs 100 may be stored in a memory unit (not shown). On the other hand, the control unit 220 of the present invention can deliver the battery cell information received from the BMS 100 via the communication unit 210 and the number of information storage battery cells to the authentication key information generation unit 230 and the first authentication key generation unit 240 for generating authentication key information and generating the first authentication key. That is, the control unit 220 can deliver the number of information storage battery cells to the authentication key information generation unit 230 for generating authentication key information and deliver the battery cell information to the first authentication key generation unit 240 for generating the first authentication key.

[0051] (3)-3. Authentication Key Information Generation Unit 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 via the communication unit 210 is stored via the control unit 220 and generates predetermined authentication key information. At this time, the authentication key information includes an arbitrary integer P satisfying 0 < P ≤ N and an arbitrary integer I satisfying 0 < P+(I + 1) ≤ N. N is the number of battery cells in which the information is stored.

[0052] (3)-4. First authentication key generation unit The first authentication key generation unit 240 generates the first authentication key using the entire battery cell information received from the BMS 100 and the authentication key information delivered from the authentication key information generation unit 230. At this time, the first authentication key generation unit 240 can generate the first authentication key using the received authentication key information, the overall battery cell voltage, the ID of the BMS, etc. For example, the first authentication key generation unit 240 uses the delivered authentication key information to sum the voltages of a predetermined number of battery cells selected from the overall battery cell information to generate a first battery cell voltage sum value, adds the ID of the BMS to the first battery cell voltage sum value, and then can generate the first authentication key by performing a crc16 hash operation. At this time, the first battery cell voltage sum value can be generated by summing the voltages from the P+0th battery cell to the P+Ith battery cell from the battery cell information. Here, P is an arbitrary integer satisfying 0<P≦_N, and I is an arbitrary integer satisfying 0<P+(I+1)≦_N.

[0053] As described above, in the ESS according to one embodiment of the present invention, the higher-level controller 200 generates authentication key information and a first authentication key using battery cell information provided by the BMS 100. When the BMS 100 provides the authentication key information and the first authentication key, the BMS 100 generates a second authentication key using the authentication key information, and then compares the first and second authentication keys to determine the truth or falsity of the control command from the higher-level controller 200. At this time, when the BMS 100 provides battery cell information to the higher-level controller 200, it stores battery cell voltage information for any N battery cells among the total battery cells managed by the BMS 100 in the memory unit and provides this to the higher-level controller 200. The higher-level controller 200 generates predetermined authentication key information using the numerical values ​​of the battery cells in which the information is stored. The higher-level controller 200 also generates a first authentication key using the battery cell information and the predetermined authentication key information, and the BMS 100 generates a second authentication key using the numerical values ​​of the information-stored cells and the received authentication key information. In this way, by comparing the first and second authentication keys generated in the higher-level controller 200 and the BMS 100, respectively, and determining the authenticity of the control command from the higher-level controller 200, it becomes possible to perform secure communication between the BMS 100 and the higher-level controller 200. Furthermore, since secure communication can be performed with minimal computation, it is possible to perform the calculations even using a Battery Monitoring IC (BMIC).

[0054] 2. Communication method for an energy storage system according to the present invention Figure 4 is a flowchart illustrating a communication method for an energy storage system according to one embodiment of the present invention.

[0055] Referring to Figure 4, the communication method according to one embodiment of the present invention includes the process of transmitting battery cell information, including the voltage information of all battery cells from the BMS 100, to a higher-level controller 200 (S110); the process of storing voltage information for any N battery cells among the plurality of battery cells managed by the BMS 100 (S120); the process of transmitting the number of stored N battery cells to the higher-level controller 200 (S130); and the process by which the higher-level controller 200 generates authentication key information using the numerical values ​​of the N battery cells for which information has been stored (S140). The process may include: generating a first authentication key using battery cell information and authentication key information (S150); transferring the first authentication key and authentication key information to the BMS 100 (S160); the BMS 100 generating a second authentication key using the number of N battery cells in which information is stored and the authentication key information (S170); comparing the first authentication key and the second authentication key to determine whether the first and second authentication keys match (S180); and determining the truth or falsity of the control command from the higher-level controller 200 based on the comparison result of the first and second authentication keys (S190). Furthermore, this series of processes (S110 to S190) can be repeated at a predetermined cycle. In other words, the battery cell information transmission process (S110), the battery cell voltage information storage process (S120), the information storage battery cell count transmission process (S130), the authentication key information generation process (S140), the first authentication key generation process (S150), the authentication key information and first authentication key transmission process (S160), the second authentication key generation process (S170), the first and second authentication key comparison process (S180), and the control command authenticity determination process (S190) can be performed at predetermined intervals. Furthermore, the above processes can be performed sequentially one by one for multiple BMS 100s managed by the higher-level controller 200, or for at least two or more BMS 100s, or for all of the multiple BMS 100s. A more detailed explanation of the ESS security communication method between the BMS 100 and the higher-level controller 200 according to this embodiment of the present invention is as follows for each process.

[0056] S110: At least one of the multiple BMS 100s transmits information about the battery 10 managed by that BMS 100 to the higher-level controller 200. At this time, the information about the battery 10 may include information about multiple battery cells managed by that BMS 100. The battery cell information may also include the battery cell voltage sensed by the sensing unit 210 that senses the battery 10. That is, at least one of the multiple BMS 100s transmits battery cell information, including the voltage information of all battery cells, to the higher-level controller 200. At this time, the battery cell information sensed by the sensing unit 210 may be passed to the communication unit 140 via the control unit 120, or it may be transmitted to the higher-level controller 200 via the communication unit 140.

[0057] The BMS100 can determine the number (N) of batteries from which cell voltage information should be transmitted, and transmit the voltage information for N battery cells to the higher-level controller 200.

[0058] The battery cell information can be transmitted to the higher-level controller 200 at a predetermined interval, and the higher-level controller 200 can update the authentication key according to the predetermined interval at which the cell information is transmitted.

[0059] S120: After transmitting battery cell information to the higher-level controller 200, the BMS100 stores voltage information for any N battery cells among the multiple battery cells managed by the BMS100. That is, the BMS100 stores voltage information for any number (i.e., N) of battery cells among the multiple battery cells in the memory unit 150. This is for use in generating the secondary authentication key, which will be described later. At this time, the arbitrary number of battery cells may be less than the total number of battery cells. Needless to say, the arbitrary number of battery cells may also be the same as the total number of battery cells.

[0060] At this time, the value of N, which is the number of battery cells for storing information, can be arbitrarily determined by the BMS. This is to enable the BMS to selectively store battery cell information only in amounts commensurate with the size of data that can fit within the capacity of the memory device possessed by the BMS. That is, in the present invention, the BMS can determine the number of battery cells for storing information in consideration of the calculation amount of the BMS.

[0061] Also, in the present invention, the cell voltage is used as the battery cell information. The cell voltage is data used in all BMSs, has versatility, has a high resolution (usually in units of 0.0001 V), and has a low data duplication probability.

[0062] S130: Transmit the number of N battery cells stored in the memory unit 150 to the upper controller 200. That is, transmit the number of any N battery cells in which voltage information is stored in the memory unit 150 to the upper controller 200. For this purpose, the control unit 120 can transmit the number of battery cells (N) stored in the memory unit 150 to the upper controller 200 via the transmission unit 140.

[0063] S140: The upper controller 200 generates authentication key information using the number value of N battery cells in which cell voltage information is stored, received from the BMS100. That is, the communication unit 210 of the upper controller 200 communicates with the communication unit 140 of the BMS100 to receive the number value (N) of the battery cells in which cell information is stored in the BMS100, and the control unit 220 passes this to the authentication key information generation unit 230. The authentication key information generation unit 230 generates authentication key information including an arbitrary integer P satisfying 0 < P ≤ N and an arbitrary integer I satisfying 0 < P+(I + 1) ≤ N.

[0064] 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 the overall battery cell information received from the BMS 100 and the authentication key information passed from the authentication key information generation unit 230. At this time, the first authentication key generation unit 240 can generate the first authentication key using the received authentication key information, the overall battery cell voltage, the ID of the BMS, etc. For example, the first authentication key generation unit 240 uses the passed authentication key information to sum the voltages of a predetermined number of battery cells selected from the overall battery cell information to generate a first battery cell voltage sum value, adds the ID of the BMS to the first battery cell voltage sum value, and then performs a crc16 hash operation to generate the first authentication key. At this time, the first battery cell voltage sum value can be generated by summing the voltages from the P + 0th battery cell to the P + Ith battery cell in the battery cell information. Here, P is an arbitrary integer satisfying 0 < P ≤ N, and I is an arbitrary integer satisfying 0 < P+(I + 1) ≤ N.

[0065] On the other hand, the first authentication key is regenerated or updated every cycle according to the transmission cycle of the battery cell information transmitted by the BMS 100 to the upper controller 200.

[0066] S160: The upper controller 200 passes 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 it to the BMS 100 via the communication unit 210.

[0067] S170: The BMS 100 generates a second authentication key using the number (N) of battery cells in 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 arbitrary battery cell information stored in the memory unit 150 and authentication key information received from the upper controller 200 via the communication unit 140. At this time, the authentication key generation unit 160 can generate a second authentication key using the received authentication key information, the voltage of a predetermined number of battery cells, the BMS's own ID, etc. For example, the authentication key generation unit 160 uses the received authentication key information to sum the voltages of a predetermined number of battery cells selected from arbitrary battery cell information to generate a second cell voltage sum value, adds the BMS's own ID to the second cell voltage sum value, and then can generate a second authentication key by performing a crc16 hash operation. At this time, the second cell voltage sum value can be generated by summing the voltages from the P+0th battery cell to the P+Ith battery cell from the battery cell information. Here, P is an arbitrary integer satisfying 0<P≦_N, I is an arbitrary integer satisfying 0<P+(I+1)≦_N, and N is the number of battery cells in which information is stored.

[0068] Thus, the authentication key of the present invention does not simply generate an authentication key using cell voltage values, but uses the sum value of cell voltages and includes the BMS ID here, so that the BMS that has received a control command can accurately distinguish a control command addressed to itself (the destination), and as a result, the security is further improved compared to the case of directly using the cell voltage value, which is normal data, for generating the authentication key. Also, in the future, when confirming a control command in the BMS, it is not necessary to decrypt all the data, and only P+1 additions and one hash operation need to be performed, so the amount of calculation is reduced compared to the conventional encryption / decryption method.

[0069] S180: The first authentication key and the second authentication key are compared to determine whether the first and second authentication keys match. That is, the authentication key comparison unit 170 compares the second authentication key generated by the second authentication key generation unit 160 with the first authentication key generated by the higher-level controller 200 to determine whether they are identical. At this time, the authentication key comparison unit 170 can pass different signals to the control unit 120 based on the comparison result of the first and second authentication keys. For example, if the first and second authentication keys are identical, a logic high signal can be passed to the control unit 120, and if they are not identical, a logic low signal can be passed to the control unit 120.

[0070] S190: Based on the comparison result of the first and second authentication keys, the authenticity of the control command from the higher-level controller 200 is determined. The determination result of the authentication key comparison unit 170 is transmitted to the control unit 120, and based on the determination result of the authentication key comparison unit 170, the control unit 120 executes the control command received from the higher-level controller 200 if the first and second authentication keys are the same, and ignores the control command received from the higher-level controller 200 if they are not the same.

[0071] <Examples> An embodiment of the authentication key generation method according to the present invention will be described when there are 5 cells connected to a BMS with ID 3, and the cell voltages are as follows.

[0072] Voltage values ​​of each cell (unit: 0.0001V): Cell1:31234 Cell2:32345 Cell3:33456 Cell4:35678 Cell5:37890

[0073] The BMS determines a predetermined N value. In this embodiment, it is assumed that N=4, and as a result, the BMS stores the data of cells 1 to 4 in the BMS memory and transmits the total cell data to the higher-level controller.

[0074] The higher-level controller determines predetermined P and I values ​​(in this embodiment, P:2, I:3), and calculates a value obtained by adding the BMS ID to the sum of the first cell voltages (Cell2 + Cell3 + Cell4) from the received data (101479 + 3 = 101482).

[0075] Subsequently, the higher-level controller generates a first authentication key by performing a hash operation on the value obtained by adding the BMS ID to the sum of the first cell voltages. The BMS also generates a second authentication key in the same manner and compares the received first authentication key with the generated second authentication key to determine the authenticity of the control command from the higher-level controller.

[0076] As described above, the technical concept of the present invention has been specifically described based on the embodiments described above, but it should be noted that these embodiments are for illustrative purposes only and not for limitation. Furthermore, those skilled in the art in the field of the present invention should understand that various embodiments are possible within the scope of the technical concept of the present invention.

[0077] The names of the reference numerals used in the drawings of this invention are as follows: [Explanation of symbols]

[0078] 10: Battery 100: Battery Management System (BMS) 200: Higher-level controller 110: Sensing Department 120: Control Unit 130: Switching section 140: Communications Department 150: Memory section 160: Second authentication key generation unit 170: Authentication Key Comparison Section 210: Communications Department 220: Control Unit 230: Authentication Key Information Generation Unit 240: First authentication key generation unit

Claims

1. Multiple battery management systems (BMS) manage multiple battery cells individually, A higher-level controller that transmits predetermined control commands to the aforementioned plurality of battery management systems (BMS), Equipped with, The aforementioned higher-level controller generates authentication key information and a first authentication key using the battery cell information provided by the battery management system (BMS). The battery management system (BMS) is an energy storage system that receives the authentication key information and a first authentication key from the higher-level controller, generates a second authentication key using the authentication key information, and then compares the first and second authentication keys to determine the authenticity of the control command from the higher-level controller.

2. The battery management system (BMS) determines the number (N) of battery cells out of the total number of battery cells managed by the BMS to which the battery cell information should be transmitted, along with the battery cell information, and provides the battery cell voltage information for the N battery cells to the higher-level controller. The higher-level controller generates the authentication key information using the individual value (N) of the battery cell, and then generates a first authentication key using the battery cell information and the authentication key information. The energy storage system according to claim 1, wherein the battery management system (BMS) generates a second authentication key using the individual value (N) of the battery cell and the received authentication key information.

3. The aforementioned higher-level controller is A communication unit that receives voltage information of the N battery cells controlled by at least one of the plurality of battery management systems (BMS), and transmits generated authentication key information and a first authentication key to the battery management system (BMS), An authentication key information generation unit generates authentication key information from the individual value (N) of the battery cell and the received battery cell information, A first authentication key generation unit generates a first authentication key using the battery cell information and the authentication key information, The energy storage system according to claim 2, comprising:

4. The energy storage system according to claim 3, wherein the first authentication key generation unit generates a first battery cell voltage sum value by summing the voltages of a predetermined number of battery cells selected from the total battery cell information using the authentication key information, adds the ID of the battery management system (BMS) to the first battery cell voltage sum value, and then performs a hash operation to generate a first authentication key.

5. The aforementioned first battery cell voltage sum is generated by summing the voltages from the P+0th battery cell to the P+1th battery cell based on the battery cell information. The energy storage system according to claim 4, wherein P and I are integers.

6. The aforementioned battery management system (BMS) is: A memory unit that stores voltage information for the N battery cells among the total battery cells managed by the aforementioned battery management system (BMS), A communication unit transmits to the higher-level controller an individual value (N) of a battery cell that stores battery cell information including voltage information of all battery cells managed by the battery management system (BMS), and receives authentication key information and a first authentication key from the higher-level controller. A second authentication key generation unit generates a second authentication key using the authentication key information and the individual value (N) of an arbitrary battery cell in which the voltage information is stored, An authentication key comparison unit that compares the first and second authentication keys, Based on the comparison results of the authentication key comparison unit, a control unit determines the authenticity of the control command from the higher-level controller, The energy storage system according to claim 2, comprising:

7. The energy storage system according to claim 6, wherein the second authentication key generation unit generates a second cell voltage sum value by summing the voltages of a predetermined number of battery cells selected from arbitrary battery cell information using the authentication key information, adds the ID of the battery management system (BMS) to the second cell voltage sum value, and then performs a hash operation to generate a second authentication key.

8. The second cell voltage sum is generated by summing the voltages from the P+0th battery cell to the P+1th battery cell from the battery cell information. The energy storage system according to claim 7, wherein P and I are integers.

9. The process by which the higher-level controller receives battery cell information, including battery cell voltage information, from the battery management system (BMS), The process by which the higher-level controller generates authentication key information and a first authentication key using the battery cell information, The process by which the battery management system (BMS) receives the authentication key information and the first authentication key from the higher-level controller, The battery management system (BMS) generates a second authentication key using the authentication key information and compares the first and second authentication keys, The process by which the battery management system (BMS) executes control commands from the higher-level controller based on the comparison results of the first and second authentication keys, A communication method for energy storage systems, including...

10. The communication method for an energy storage system according to claim 9, wherein the first authentication key is generated by summing the voltages of a predetermined number of battery cells selected from the total battery cell information using the authentication key information to generate a first battery cell voltage sum value, adding the ID of the battery management system (BMS) to the first battery cell voltage sum value, and then performing a hash operation.

11. The aforementioned first battery cell voltage sum is generated by summing the voltages from the P+0th battery cell to the P+1th battery cell based on the battery cell information. A communication method for an energy storage system according to claim 10, wherein P is any integer satisfying 0 < P ≤ N, I is any integer satisfying 0 < P + (I + 1) ≤ N, and N is the individual value of a battery cell in which cell information is stored.

12. The communication method for an energy storage system according to claim 9, wherein the second authentication key is generated by summing the voltages of a predetermined number of battery cells selected from arbitrary battery cell information using the authentication key information to generate a second cell voltage sum value, adding the ID of the battery management system (BMS) to the second cell voltage sum value, and then performing a hash operation.

13. The second cell voltage sum is generated by summing the voltages from the P+0th battery cell to the P+1th battery cell from the battery cell information. A communication method for an energy storage system according to claim 12, wherein P and I are integers and N is the individual value of a battery cell in which cell information is stored.

14. The process of transmitting battery cell information, including the voltage information of all battery cells, from the battery management system (BMS) to the higher-level controller, The process of storing voltage information for any N battery cells among the multiple battery cells managed by the aforementioned battery management system (BMS), The process of transmitting the number of stored N battery cells to the higher-level controller, The process by which the above-level controller generates authentication key information using the individual values ​​of N battery cells in which voltage information is stored, A process of generating a first authentication key using the battery cell information and the authentication key information, The process of transmitting the first authentication key and the authentication key information to the battery management system (BMS), The aforementioned battery management system (BMS) includes a process of generating a second authentication key using the number of N battery cells in which voltage information is stored and authentication key information, A process of comparing the first authentication key and the second authentication key to determine the truth or falsity of the control command from the higher-level controller, A communication method for energy storage systems, including...

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