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 and resource depletion being regarded as problems, interest in systems that can store electricity and efficiently utilize the stored electricity is increasing. At the same time, interest in renewable energy that does not cause pollution in the power generation process is also 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 carried out in line with today's environmental changes. That is, the 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, the ESS includes a battery for storing electricity and equipment for efficiently managing and controlling the battery.

[0003] The ESS may include a plurality of batteries for storing power, but the ESS may also include at least one battery bank. 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 the ESS may be constituted by at least one battery bank.

[0004] For such an ESS, it is important to efficiently manage various matters such as battery charging, discharging, and cell balancing. By efficiently managing the battery, the battery life can be extended, and power can be stably provided to the load. For this purpose, the ESS may be equipped with a Battery Management System (BMS). The BMS monitors the battery state such as voltage, current, and temperature to keep the battery in an optimal state. In addition, the BMS manages the battery system including the battery and its peripheral devices by predicting the battery replacement time and detecting battery problems in advance. Such a BMS may be provided in each of the battery bank, battery rack, and battery module. That is, each of the battery bank, battery rack, and battery module is equipped with a Bank BMS (BBMS), Rack BMS (RBMS), and Module BMS (MBMS). In addition, the ESS is equipped with 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 as BSC-BBMS-RBMS-MBMS. For example, control commands from the BSC are delivered to the BBMS, RBMS, and MBMS to manage the battery.

[0005] On the one hand, for various research and development purposes, various data collected by the BMS can also be stored in a central server at a remote location or the like. That is, for the ESS, controllers for battery control, such as BSCs, are increasingly being exposed to the public Internet for remote control and remote monitoring. However, when the controller is exposed, it has security vulnerabilities such as being exposed to malware infections and attacks from hackers. Also, considering the characteristics of the ESS that handles huge amounts of electrical energy, there is also a possibility of causing significant physical damage due to threats from hackers or unauthorized control. Such problems can also be prevented by applying an encryption method to the communication between the controller and the lower-level BMS. However, encrypting the entire communication requires a great deal of computing operations, which is a heavy burden on the battery monitoring IC (BMIC), which uses relatively lower computing power compared to a personal computer (PC).

[0006] Regarding this, Patent Document 1 presents a battery pack equipped with a wireless communication module and discloses a technique for generating an authentication number of the battery pack and authenticating the battery pack with an external electronic device to which it is connected. Patent Document 2 discloses a battery system that performs mutual authentication using an authentication key between a master BMS and a slave BMS.

[0007] Also, 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 data packets to an external device. Patent Document 4 discloses a method for generating a secret key that generates a primary secret key using the voltage measured in a battery, transmits it to an external device, receives a secondary secret key generated using the primary secret key in the external device, and performs an operation using the primary secret key and the secondary secret key to finally generate the secret key.

[0008] However, in the above-mentioned conventional patent documents, it is not possible to present a method of verifying the authenticity of a control command by checking an authentication key for transmission of a control command or the like between a battery management device and a host controller. When generating an authentication key and encrypting data, the entire data is encrypted, so there is a problem that computing resources cannot be used efficiently.

[0009] The prior art is as follows.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0011] The present invention provides an energy storage system capable of secure communication between a controller and a lower-level BMS and a communication method thereof.

[0012] The present invention provides an energy storage system and a communication method thereof that generate first and second authentication keys in a controller and a lower-level BMS, respectively, and compare them to determine the authenticity of a control command from the controller.

[0013] Further, the present invention provides a communication method between a BMS and a controller that efficiently uses computing resources to generate an authentication key and uses the same.

Means for Solving the Problems

[0014] An energy storage system according to an embodiment of the present invention includes a plurality of BMSs that manage a plurality of battery cells respectively, 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 BMS. After the BMS generates a second authentication key using the authentication key information from the host controller, the BMS compares 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 the authentication key information and the first authentication key to the BMS; 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 generates a first total battery cell voltage value by adding up the voltages of a predetermined number of battery cells selected from the overall battery cell information using the authentication key information, adds the ID of the BMS to the first total battery cell voltage value, and then performs a crc16 hash operation to generate a first authentication key.

[0019] The first total battery cell voltage value is 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 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 voltage information of any N battery cells among the overall battery cells managed by the BMS, a communication unit that transmits battery cell information including the voltage information of the overall 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 a control command from the upper controller based on the comparison result of the authentication key comparison unit.

[0021] The second authentication key generation unit generates a second cell voltage total value by adding up 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 BMS to the second cell voltage total value, and then performs a crc16 hash operation to generate a second authentication key.

[0022] The second combined cell voltage 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] A communication method of an 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 combined battery cell voltage value, adding the ID of the BMS to the first combined battery cell voltage value, and then performing a crc16 hash operation.

[0026] The first combined battery cell voltage 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+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 information is stored.

[0029] The communication method of the 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 the upper 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 upper controller, a process of the upper 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 the control command from the upper controller.

Effects of the Invention

[0030] When the host 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 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 host controller. At this time, when the BMS provides battery cell information to the host controller, the BMS stores battery cell voltage information regarding any N battery cells among all the battery cells it manages in the memory unit, provides this to the host controller, and the host controller generates predetermined authentication key information using the number value of the battery cells in which the information is stored. Further, the host 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 cells in which the information is stored and the received authentication key information.

[0031] As described above, by comparing the first and second authentication keys respectively generated in the host controller and the lower-level BMS to determine the authenticity of the control command from the controller, secure communication between the BMS and the controller is possible. Also, since secure communication is possible with few calculations, calculations are also possible using a battery monitoring IC (BMIC: Battery Monitoring IC).

Brief Description of the Drawings

[0032]

Figure 1

Figure 2

Figure 3

Figure 4

Best Mode for Carrying Out the Invention

[0033] Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and can be embodied in various different forms. These embodiments are provided merely to make the disclosure of the present invention complete and to fully inform those with ordinary knowledge of the scope of the invention.

[0034] 1. Energy Storage System for Performing Authentication Key Communication According to the Present Invention FIG. 1 is a block diagram for explaining the configuration of an energy storage system according to an embodiment of the present invention, FIG. 2 is a block diagram for explaining the configuration of a BMS constituting the energy storage system according to an embodiment of the present invention, and FIG. 3 is a block diagram for explaining the configuration of a host controller constituting the energy storage system according to an embodiment of the present invention.

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

[0036] In addition, in the energy storage system according to the present invention, the host controller 200 generates a first authentication key and authentication key information using the battery cell information provided from the BMS 100 and provides the same 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 authenticity of the control command from the host controller 200. At this time, if the first and second authentication keys are the same, it is determined that the control command has been transmitted from the host controller 200, and if the first and second authentication keys are not the same, it is determined that the control command is false. If the energy storage system according to such an embodiment of the present invention is further described in more detail for each component, it is as follows.

[0037] (1) Battery The battery 10 can be charged by receiving power supply and can discharge the charged electrical energy to supply it to the power-consuming device. That is, the battery 10 can be charged and discharged and can be used as an energy source for the power-consuming device. Here, the battery 10 may include 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, 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; or when 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, a battery rack in which a plurality of battery modules are bundled, or a battery bank in which a plurality of battery racks are bundled. 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 in parallel in various ways. Needless to say, a plurality of battery modules each including a plurality of battery cells can also be connected in series and / or in parallel. Here, the battery cell may include a lithium-ion battery. However, the battery cell may be composed of not only a lithium-ion battery but also a lithium polymer battery, a nickel cadmium battery, a nickel metal hydride battery, a nickel zinc battery, etc.

[0038] (2) BMS (Battery Management System) 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 such as the voltage, current, and temperature of the battery 10, and uses the state information to estimate the state of charge (SOC), state of health (SOH), and state of power (SOP) of the battery. The SOC indicates the remaining capacity of the battery, and an accurate prediction of the SOC enables the prediction of the future driving distance. The SOH indicates the capacity of the battery, which means the aging state of the battery and affects the number of charge and discharge cycles of the battery. The SOP means the maximum power that the battery can support. The prediction regarding the maximum power helps prevent overcharging and heat loss of the battery. Using such state information, the BMS 100 controls the charging or discharging of the battery 10. For this purpose, as shown in FIG. 2, the BMS 100 may include a sensing unit 110 that senses the state of the battery 10, a control unit 120 that generates 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 switching unit 130 that switches the connection between the battery 10 and an external power source or a power-consuming device based on the control signal of the control unit 120 to enable charging and discharging. Also, the BMS 100 according to an embodiment of the present invention transmits battery cell information to the upper controller 200 and stores information regarding at least one, that is, N arbitrarily selected battery cells. Then, the BMS 100 receives the 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. Further, the BMS 100 compares the generated second authentication key with the received first authentication key, and if they are the same, executes the command received from the upper controller 200, and if they are not the same, ignores the command received from the upper controller 200.For this purpose, the BMS 100 according to an embodiment of the present invention may include a communication unit 140 for communication with the upper controller 200, a memory unit 150 for storing information of 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. At this time, based on the comparison result of the authentication key comparison unit 170, the control unit 120 determines the authenticity of the control command. That is, as a result of the comparison by the authentication key comparison unit 170, if the first and second authentication keys are the same, the control unit 120 executes the control command from the upper controller 200, and if they 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 not only the switching unit 130 for charging and discharging the battery 10 but also each component of the BMS 100. That is, the control unit 120 can control the communication unit 140 to provide battery cell information to be provided to the upper controller 200, can also store the battery cell information in the memory unit 150, and can execute the control command from the upper 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 generating and comparing authentication keys. Eventually, the energy storage system (ESS) for secure communication of the present invention may have the BMS 100 including 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 one hand, the BMS 100 may be a plurality of module BMSs (MBMSs) for managing a plurality of battery modules of a predetermined number respectively, or may be a plurality of rack BMSs (RBMSs) for managing a plurality of module BMSs (MBMSs) of a predetermined number respectively, or may be at least one bank MBS (BBMS) for managing a plurality of rack BMSs (RBMSs) of a predetermined number respectively. That is, in the present invention, at least any one of the module BMS, the rack BMS, and the bank BMS can generate an authentication key through communication with the upper controller 200, and compare and determine the authenticity of the control command from the upper controller 200.

[0040] If the BMS 100 according to an embodiment of the present invention is further described in more detail for each component, it 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. Further, the sensing unit 100 can sense the states such as the current and voltage of the battery module and the battery cells. That is, it can also sense the state of each of the plurality of battery cells, and can also sense the state of the battery module in which the plurality of battery cells are bundled. For this purpose, the sensing unit 110 may include a plurality of sensors. That is, it may include 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 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. Also, 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 discharging current. The temperature sensor may be, for example, a thermocouple used for temperature measurement. 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 lifespan management of the battery 10, capacity control of the battery 10, and battery balancing. Further, the control unit 120 generates a control signal based on the voltage measured by the sensing unit 110 and controls the switching unit 130 between the battery 10 and the external power supply, thereby controlling the charging and discharging of the battery 10 and preventing overcharging or overdischarging of the battery cells. For example, the control unit 120 compares the first set voltage for stopping the charging operation and the second set voltage for implementing the charging operation with the voltage of the battery 10 measured by the sensing unit 110. When the measured voltage is higher than or equal to the first set voltage, a control signal for stopping the charging operation of the battery 10 is generated. When the measured voltage is lower than or equal to the second set voltage, a control signal for the charging operation of the battery 10 can be generated. Furthermore, the control unit 120 provides battery cell information for providing to the upper controller 200, performs an operation according to a control command from the upper controller 200, and for this purpose, can control the communication unit 140. That is, the control unit 120 can transmit the battery cell information to the upper controller 200 via the communication unit 140 and can receive a control command from the upper controller 200 via the communication unit 140. Then, the control unit 120 selects at least one battery cell information out of the entire battery cell information, that is, N pieces of battery cell information, stores it in the memory unit 150, and transmits the number information (N) of the battery cells storing the battery cell information to the upper controller 200. At this time, the battery cell information may include the voltage of the battery cell. Furthermore, the control unit 120 determines the authenticity of the control command based on the comparison result of the authentication key comparison unit 170 that compares the first authentication key from the upper controller 200 and the second authentication key from the second authentication key generation unit 160, and can execute the control command from the upper controller 200.

[0043] (2)-3. Switching Unit The switching unit 130 may be provided to control the flow of current related to the charging or discharging of the battery 10. That is, the switching unit 130 may be provided on the charging and discharging paths to set the charging and discharging paths. At this time, 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 be composed of a semiconductor switching element for controlling the flow of current related to charging or discharging. For example, at least one field effect transistor (FET), relay, etc. can be used according to the specifications of the battery 10. Taking a specific example, the switching unit 130 may be composed of a charging switch and a discharging switch that are respectively driven based on the control signal of the control unit 120. At this time, the charging and discharging switches may each be composed of an FET.

[0044] (2)-4. Communication unit 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 receive control commands, etc. from the upper controller 200. Also, the communication unit 140 can receive the first authentication key and authentication key information from the upper controller 200. The control command from the upper controller 200 received via the communication unit 140 can be delivered to the control unit 120, the authentication key information from the upper controller 200 can be delivered to the authentication key generation unit 160, and the first authentication key from the upper controller 200 can be delivered to the authentication key comparison unit 170. Here, the communication unit 140 can communicate with the upper controller 200 by wire or wirelessly. For example, the communication unit 140 can communicate with the upper controller 200 by the Controller Area Network (CAN) or the Local Interconnect Network (LIN) method.

[0045] (2)-5. Memory unit When transmitting battery cell information to the upper controller 200, the memory unit 150 stores voltage information regarding any N battery cells. That is, the memory unit 150 can store any battery cell information selected by the control unit 120 via the control unit 120. Further, the memory unit 150 can store information such as the unique ID of the BMS 100, and can store unique characteristic information of the battery 10 for charging and discharging operations of the battery 10 and the like. Such a memory unit 150 may include a storage medium such as a random access memory (RAM), a static random access memory (SRAM), a ferroelectric random access memory (FRAM (registered trademark)), a phase change random access memory (PRAM), a magnetic random access memory (MRAM), a flash memory, an electrically erasable programmable read-only memory (EEPROM), a read-only memory (ROM), or a 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 to determine 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, based on the comparison result of the authentication key comparison unit 170, executes the control command received from the upper controller 200 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 upper controller 200 may be provided for controlling the ESS. That is, the upper controller 200 may be provided for controlling a plurality of BMSs 100. The upper controller 200 can transmit a control command for controlling a plurality of batteries 10 to the BMS 100. Thereby, the operation of the BMS 100 is controlled based on the control command received from the upper controller 200, and thereby, operations such as charging and discharging of the battery 10 can be controlled. Here, the upper controller 200 may be a battery system controller (BSC) for controlling the ESS. Further, the upper controller 200 according to an embodiment of the present invention can generate authentication key information for security communication with the BMS 100 and generate a first authentication key therefrom. For this purpose, the upper controller 200 periodically delivers the overall battery cell information from the plurality of BMSs 100 and receives the number of battery cell information currently stored in each of the BMSs 100. Then, the upper controller 200 generates predetermined authentication key information using the number value of the battery cells in which the information is stored (that is, the N value), and generates a first authentication key using the battery cell information and the authentication key information. Further, the upper controller 200 transmits the first authentication key and the authentication key information to the BMS 100.

[0049] (3)-1. Communication unit The communication unit 210 may be provided for communication between the upper controller 200 and the BMS 100. Also, the communication unit 210 may be provided for communication between the upper controller 200 and a server via a network. That is, the communication unit 210 may be provided to receive battery cell information etc. from the BMS 100 and transmit control commands etc. from the upper controller 200 to the BMS 100. Further, the communication unit 210 can transmit the first authentication key and authentication key information from the upper controller 200 to the BMS 100. Such a communication unit 210 can communicate with the BMS 100 by wire or wirelessly. For example, the communication unit 210 can communicate with the BMS 100 by a controller area network (CAN) or a local interconnect network (LIN) method. On the other hand, the communication unit 210 can also communicate with a server (not shown) via a network. As communication using the network, wireless communication can be used. That is, the communication unit 210 can communicate with the BMS 100 by wire or wirelessly and communicate with a server (not shown) wirelessly via a network. Therefore, the communication unit 210 of the upper controller 200 may include a wired communication unit and a wireless communication unit. Here, for wireless communication using a network, various methods can be used, including the third generation (3G), the fourth generation (4G), the fifth generation (5G), the third generation partnership project (3GPP (registered trademark)), long term evolution (LTE), world interoperability for microwave access (WIMAX), Wi-Fi, Bluetooth (registered trademark) communication, infrared communication, ultrasonic communication, visible light communication (VLC), etc.

[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 and cell balancing that are managed by the plurality of BMSs 100. At this time, the control unit 220 generates control commands for controlling the battery 10 to an optimal state by 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 commands from the control unit 220 are delivered to the plurality of BMSs 100 via the communication unit 210. Also, 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 by 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 that satisfies 0 < P ≤ N and an arbitrary integer I that satisfies 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 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 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, for the ESS according to an embodiment of the present invention, when the host controller 200 generates authentication key information and a first authentication key using the battery cell information provided from the BMS 100 and provides the authentication key information and the first authentication key 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 authenticity of the control command from the host controller 200. At this time, when the BMS 100 provides the battery cell information to the host controller 200, the BMS 100 stores the battery cell voltage information regarding any N battery cells among all the battery cells managed by the BMS 100 in the memory unit, provides this to the host controller 200, and the host controller 200 generates predetermined authentication key information using the number value of the battery cells in which the information is stored. Further, the host controller 200 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 number value of the information storage cells and the received authentication key information. In this way, by comparing the first and second authentication keys respectively generated in the host controller 200 and the BMS 100 to determine the authenticity of the control command from the host controller 200, it becomes possible to perform secure communication between the BMS 100 and the host controller 200. Also, since it is possible to perform secure communication with a small number of operations, it is also possible to perform operations using a battery monitoring IC (BMIC: Battery Monitoring IC).

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

[0055] Referring to FIG. 4, a communication method according to an embodiment of the present invention includes: a process (S110) of transmitting battery cell information including voltage information of all battery cells from the BMS 100 to the upper controller 200; a process (S120) of storing voltage information regarding any N battery cells among the plurality of battery cells managed by the BMS 100; a process (S130) of transmitting the number of the stored N battery cells to the upper controller 200; a process (S140) in which the upper controller 200 generates authentication key information using the number value of the N battery cells in which information is stored; a process (S150) of generating a first authentication key using the battery cell information and the authentication key information; a process (S160) of delivering the first authentication key and the authentication key information to the BMS 100; a process (S170) in which the BMS 100 generates a second authentication key using the number of the N battery cells in which information is stored and the authentication key information; a process (S180) of comparing the first authentication key and the second authentication key to determine whether the first and second authentication keys match; and a process (S190) of determining the authenticity of a control command from the upper controller 200 based on the comparison result of the first and second authentication keys. Further, such a series of processes (S110 to S190) can be repeatedly performed at a predetermined period. That is, the battery cell information transmission process (S110), the battery cell voltage information storage process (S120), the information storage battery cell number 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 implemented at a predetermined period. Further, the above processes can be sequentially implemented one by one for each of the plurality of BMSs 100 managed by the upper controller 200, the above processes can also be implemented for at least two or more BMSs 100, and the above processes can also be implemented for the entirety of the plurality of BMSs 100. If the security communication method of the ESS between the BMS 100 and the upper controller 200 according to such an embodiment of the present invention is further described in more detail for each process, it is as follows.

[0056] S110: Transmit information of the battery 10 managed by at least one of the plurality of BMSs 100 to the upper controller 200 from at least one BMS 100 among the plurality of BMSs 100. At this time, the information of the battery 10 may include information of a plurality of battery cells managed by the BMS 100. Also, the battery cell information may include the battery cell voltage sensed from the sensing unit 210 that senses the battery 10. That is, at least one BMS 100 among the plurality of BMSs 100 transmits battery cell information including voltage information of all the battery cells to the upper controller 200. At this time, the battery cell information sensed from the sensing unit 210 may be delivered to the communication unit 140 via the control unit 120, or may be transmitted to the upper controller 200 via the communication unit 140.

[0057] The BMS 100 can determine the number (N) of cells for which cell voltage information among the plurality of battery cells is to be transmitted, and transmit voltage information regarding N battery cells to the upper controller 200.

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

[0059] S120: After the BMS 100 transmits the battery cell information to the upper controller 200, the BMS 100 stores voltage information regarding any N battery cells among the plurality of battery cells managed by the BMS 100. That is, the BMS 100 stores voltage information regarding an arbitrary number (that is, N) of battery cells among the plurality of battery cells in the memory unit 150. This is for use in generating a secondary authentication key described later. At this time, the arbitrary number of battery cells may be smaller than the total number of battery cells. Needless to say, the arbitrary number of battery cells may 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 an amount corresponding to the size of the data that fits 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 and 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 that satisfies 0 < P ≤ N and an arbitrary integer I that satisfies 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 entire battery cell information received from the BMS100 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 entire 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.

[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 BMS100 to the upper controller 200.

[0066] S160: The upper controller 200 passes the first authentication key and the authentication key information to the BMS100. 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 BMS100 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 voltages of a predetermined number of battery cells, the BMS's own ID, and the like. 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 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 information is stored.

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

[0069] S180: Compare the first authentication key and the second authentication key 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 from the upper controller 200 to determine whether they are 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.

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

[0071] <Example> When the number of cells connected to the BMS with ID 3 is 5, and the cell voltages are as follows, an example of the generation of the authentication key in the present invention will be described.

[0072] Voltage value 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 example, it is assumed that N = 4. Accordingly, the BMS stores the data of cells 1 to 4 in the BMS memory and transmits the entire cell data to the upper controller.

[0074] The upper 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 first cell voltage sum value (Cell2 + Cell3 + Cell4) from the received data (101479 + 3 = 101482).

[0075] After that, the upper controller generates a first authentication key as a value obtained by performing a hash operation on the value obtained by adding the BMS ID to the first cell voltage sum value, and also generates a second authentication key in the BMS in the same way, and compares the first authentication key received with the second authentication key generated to determine the authenticity of the control command from the upper controller.

[0076] As described above, although the technical idea of the present invention has been specifically described based on the above embodiment, it should be noted that the above embodiment is for the purpose of explanation and not for limitation. It should be understood that those skilled in the technical field of the present invention can implement various embodiments within the scope of the technical idea of the present invention.

[0077] The names of the reference numerals used in the present invention are as follows.

Explanation of Reference Numerals

[0078] 10: Battery 100: Battery Management System (BMS) 200: Upper Controller 110: Sensing Unit 120: Control Unit 130: Switching Unit 140: Communication Unit 150: Memory Unit 160: Second Authentication Key Generation Unit 170: Authentication Key Comparison Unit 210: Communication Unit 220: Control Unit 230: Authentication Key Information Generation Unit 240: First Authentication Key Generation Unit

Claims

1. A plurality of battery management systems (BMSs) each managing a plurality of battery cells, and a host controller that transmits a predetermined control command to the plurality of battery management systems (BMSs), comprising: The host controller generates authentication key information and a first authentication key using the battery cell information provided from the battery management system (BMS), The battery management system (BMS) receives the authentication key information and the first authentication key from the host 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 host controller. An energy storage system.

2. The battery management system (BMS) determines the number (N) of battery cells for which battery cell information is to be transmitted among all the battery cells managed by the battery management system (BMS) together with the battery cell information, and provides battery cell voltage information regarding N battery cells to the host controller, The host controller generates the authentication key information using the number value (N) of the battery cells, and then generates a first authentication key using the battery cell information and the authentication key information, The battery management system (BMS) generates a second authentication key using the number value (N) of the battery cells and the received authentication key information. The energy storage system according to claim 1.

3. The host controller, a communication unit that receives voltage information of the N battery cells controlled by at least one battery management system (BMS) among the plurality of battery management systems (BMSs), and transmits the generated authentication key information and the first authentication key to the battery management system (BMS), an authentication key information generation unit that generates authentication key information from the number value (N) of the battery cells 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. The energy storage system according to claim 2.

4. 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. The energy storage system according to claim 3.

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

6. The first combined battery 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. 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. The energy storage system according to claim 5.

7. The battery management system (BMS) a memory unit that stores the voltage information of any N battery cells among all the battery cells managed by the battery management system (BMS); a communication unit that transmits the number value (N) of the battery cells in which the battery cell information including the voltage information of all the battery cells managed by the battery management system (BMS) is stored to the upper controller, and receives the authentication key information and the first authentication key from the upper controller; a second authentication key generation unit that generates a second authentication key using 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; 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; The energy storage system according to claim 2, comprising:

8. The second authentication key generation unit generates a second combined cell voltage value by adding up 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 combined cell voltage value, and then performs a hash operation to generate a second authentication key. The energy storage system according to claim 7.

9. 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. 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 battery cells in which cell information is stored. The energy storage system according to claim 8.

10. A process in which a host controller receives the provision of battery cell information including battery cell voltage information from a battery management system (BMS); A process in which the host controller generates authentication key information and a first authentication key using the battery cell information; A process in which the battery management system (BMS) receives the provision of authentication key information from the host controller, generates a second authentication key, and compares it with the first authentication key; A process in which the battery management system (BMS) executes a control command from the host controller based on the comparison result of the first and second authentication keys; A communication method of an energy storage system including the above.

11. The authentication key information includes an arbitrary integer P satisfying 0 < P ≤ _N and an arbitrary integer I satisfying 0 < P + (I + 1) ≤ _N. The communication method of the energy storage system according to claim 10.

12. The first authentication key is generated by adding up 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, adding the ID of the battery management system (BMS) to the first battery cell voltage sum value, and then performing a hash operation. The communication method of the energy storage system according to claim 10.

13. The first battery cell voltage sum 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. 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 battery cells in which cell information is stored. The communication method of the energy storage system according to claim 12.

14. The second authentication key is generated by adding up 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. The communication method of the energy storage system according to claim 10.

15. The second cell voltage sum value is generated by summing the voltages from the P+0th battery cell to the P+Ith battery cell from the battery cell information, where 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. The communication method of the energy storage system according to claim 14.

16. The process of transmitting battery cell information including the voltage information of all battery cells from the battery management system (BMS) to the upper controller, The process of storing the voltage information regarding any N battery cells among the plurality of battery cells managed by the battery management system (BMS), The process of transmitting the number of the N stored battery cells to the upper controller, The process in which the upper controller generates authentication key information using the number value of the N battery cells in which the voltage information is stored, The 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 battery management system (BMS) generates a second authentication key using the number of the N battery cells in which the voltage information is stored and the authentication key information, The process of comparing the first authentication key and the second authentication key to determine the authenticity of the control command from the upper controller, A communication method for an energy storage system, including the above.

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