Battery management method and battery system using the same

Abstract

A management method for a battery system, the battery system comprising a plurality of battery packs, a plurality of slave battery management systems, and a master battery management system connected to the slave battery management systems via wireless communication, the management method comprising: determining whether a wireless communication failure occurs between a master device and at least one of a plurality of slave devices; if a wireless communication failure occurs, receiving road condition information on which a vehicle equipped with the battery system is currently located; determining whether the vehicle is located on a road that can cause cell overvoltage / low voltage based on the road condition information; if the current position of the vehicle is located on a road that can cause cell overvoltage / low voltage, setting a first fault confirmation time; if the current position of the vehicle is not located on a road that can cause cell overvoltage / low voltage, setting a second fault confirmation time; and if a wireless communication failure interval from the time when the wireless communication failure occurs to the current time reaches the first fault confirmation time or the second fault confirmation time, entering a safety mode, wherein the second fault confirmation time is longer than the first fault confirmation time.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0146744 filed in the Korean Intellectual Property Office on November 5, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a battery management method and a battery system using the battery management method. Background Art

[0004] In a wireless battery management system (BMS), a master BMS and a slave BMS transmit and receive data through wireless communication such as radio frequency (RF) communication. Compared with a conventional method in which a master BMS and a slave BMS transmit and receive data via wires, the number of communication failures increases, while the recovery rate of restoring communication failures to normal is high.

[0005] In a conventional wired manner, if a communication failure occurs between a slave BMS monitoring a cell voltage and a master BMS, it is difficult to restore the communication failure to normal. In a communication failure state, since the master BMS cannot know the cell voltage, the master BMS enters a safety mode that disconnects a relay to block the battery system from external connection for a short time after a communication failure occurs.

[0006] However, even in the wireless method, as in the conventional wired method, if the main BMS enters a safety mode whenever a communication failure occurs, the stability and marketability of the battery system are deteriorated due to frequent relay disconnections. Summary of the invention

[0007]

Technical issues

[0008] An object of the present invention is to provide a battery management method and a battery system that can reliably diagnose whether a wireless communication failure occurs in a wireless method.

[0009]

Technical solution

[0010] A management method for a battery system according to the present disclosure, the battery system includes multiple battery packs, multiple slave battery management systems, and a master battery management system connected to the slave battery management systems via wireless communication, the management method including: determining whether a wireless communication failure occurs between a master device and at least one of the multiple slave devices; if a wireless communication failure occurs, receiving road condition information on which a vehicle equipped with the battery system is currently located; determining whether the vehicle is located on a road that can cause cell overvoltage / low voltage based on the road condition information; if the current position of the vehicle is located on a road that can cause cell overvoltage / low voltage, setting a first fault confirmation time; if the current position of the vehicle is not located on a road that can cause cell overvoltage / low voltage, setting a second fault confirmation time; and entering a safety mode if a wireless communication failure interval from the time when the wireless communication failure occurs to the current time reaches the first fault confirmation time or the second fault confirmation time, wherein the second fault confirmation time is longer than the first fault confirmation time.

[0011] Determining whether the vehicle is located on a road that can cause cell overvoltage / low voltage based on road condition information may include: when the road condition information is any one of a highway, an uphill road, and a downhill road, determining that the current position of the vehicle is located on a road that can cause cell overvoltage / low voltage.

[0012] The battery management method may further include deriving a wireless communication failure interval from a time when the wireless communication failure occurs to a current time.

[0013] The battery management method may further include: when the current position of the vehicle is on a road that can cause cell overvoltage / low voltage, if the wireless communication fault section does not reach the first fault confirmation time, determining whether the wireless communication fault is maintained.

[0014] The battery management method may further include determining whether the wireless communication fault is maintained if the wireless communication fault interval does not reach the second fault confirmation time when the current position of the vehicle is not located on a road that can cause cell overvoltage / low voltage.

[0015] The battery management method may further include disconnecting a relay between the vehicle and the battery system depending on the safety mode.

[0016] A battery system according to the present disclosure includes: a battery pack, which includes a plurality of battery cells and a slave battery management system; a master battery management system, which is connected to the slave battery management system via wireless communication; and at least one relay, which is connected between a vehicle and the battery pack, wherein, if a fault occurs in the wireless communication with the slave battery management system, the master battery management system receives road condition information on which the vehicle is currently located, determines whether the vehicle is located on a road that can cause cell overvoltage / low voltage based on the road condition information, sets a first fault confirmation time if the current position of the vehicle is located on a road that can cause cell overvoltage / low voltage, sets a second fault confirmation time if the current position of the vehicle is not located on a road that can cause cell overvoltage / low voltage, and enters a safety mode if a wireless communication fault interval from the time when the wireless communication fault occurs to the current time reaches the first fault confirmation time or the second fault confirmation time, and the second fault confirmation time is longer than the first fault confirmation time.

[0017] When the road condition information is any one of high speed, uphill or downhill, the main battery management system can determine that the current position of the vehicle is located on a road that can cause cell overvoltage / low voltage.

[0018] The master battery management system may derive a wireless communication failure interval from the time when the wireless communication failure occurs to the current time.

[0019] When the current position of the vehicle is on a road that can cause cell overvoltage / low voltage, if the wireless communication fault interval does not reach the first fault confirmation time, the master battery management system may determine whether the wireless communication fault is maintained.

[0020] When the current position of the vehicle is not located on a road that can cause cell overvoltage / low voltage, if the wireless communication fault interval does not reach the second fault confirmation time, the master battery management system can determine whether the wireless communication fault is maintained.

[0021] The master battery management system may open at least one relay depending on the safety mode.

[0022]

Beneficial Effects

[0023] The wireless method is to provide a battery management method and a battery system that can adjust the time for determining whether a failure occurs in consideration of a situation in which the battery system is used when a wireless communication failure occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 are views illustrating a battery system and a vehicle equipped with the battery system according to an exemplary embodiment.

[0025] Figure 2 It is shown Figure 1 A view of one of the multiple battery packs shown.

[0026] Figure 3 is a view illustrating a master BMS according to an exemplary embodiment.

[0027] Figure 4 is a view illustrating a fault confirmation time control method according to an exemplary embodiment. DETAILED DESCRIPTION

[0028] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings. In this specification, the same or similar components will be represented by the same or similar reference numerals, and their overlapping descriptions will be omitted. The component terms "module" and "unit" used in the following description are used only for easy explanation. Therefore, these terms themselves do not have the meaning or function of distinguishing them from each other. In addition, when describing the embodiments of this specification, when it is determined that the detailed description of the known technology associated with the present invention may confuse the main purpose of the present invention, the detailed description will be omitted. In addition, the accompanying drawings are provided only to allow easy understanding of the embodiments disclosed in this specification, and should not be interpreted as limiting the spirit disclosed in this specification, and it should be understood that the present invention includes all modifications, equivalents and replacements without departing from the scope and spirit of the present invention.

[0029] Terms including ordinal numbers such as first, second, etc. will be used only to describe various components and are not interpreted as limiting these components. These terms are used only to distinguish one component from other components.

[0030] It should be understood that when one component is referred to as being “connected” or “coupled” to another component, it may be directly connected or coupled to the other component, or connected or coupled to the other component with another component interposed therebetween. On the other hand, it should be understood that when one component is referred to as being “directly connected or coupled” to another component, it may be connected or coupled to the other component without another component interposed therebetween.

[0031] It should be further understood that the terms “including” or “having” used in this specification specify the existence of stated features, numbers, steps, operations, components, parts or combinations thereof, but do not preclude the existence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0032] Figure 1 are views illustrating a battery system and a vehicle equipped with the battery system according to an exemplary embodiment.

[0033] The power device 2 of the vehicle 3 is connected to the two output terminals P+ and P- of the battery system 1. The vehicle 3 may be one of an electric vehicle, a hybrid vehicle, a plug-in hybrid vehicle, etc., and the power device 2 receives power from the battery system 1 and supplies the power to the motor 21, or may receive power from a charger connected to the charging terminal 22. When the power device 2 is connected to the charger through the charging terminal 22, the power of the charger may be converted into power suitable for the battery system 1 and supplied to the battery system 1. The power device 2 includes an electronic control unit (ECU) (ECU1, 20) for controlling the power supply and charging operations as described above.

[0034] The vehicle 3 further includes a navigation device 4 that detects the position of the vehicle, guides a route from a starting position to a destination, or displays traffic information at a current position. The navigation device 4 includes a satellite GPS 41 for determining the position of the vehicle 3, a communication module 42 for requesting and receiving information through wireless communication with a traffic information server, and an electronic control unit (ECU) (ECU2, 40) for controlling the operation of the navigation device 4.

[0035] In the battery system 1, six battery packs 11 to 16 are connected in parallel, an output terminal P+ of the battery system 1 is connected to each output terminal (+) of the battery packs 11 to 16 via a relay 17, and an output terminal P- is connected to each output terminal (-) of the battery packs 11 to 16 via a relay 18. One terminal of the relay 17 is connected to each output terminal (+) of the battery packs 11 to 16, the other terminal of the relay 17 is connected to the output terminal P+, one terminal of the relay 18 is connected to each output terminal (-) of the battery packs 11 to 16, and the other terminal of the relay 18 is connected to the output terminal P-.

[0036] like Figure 1 As shown, the battery system 1 includes slave battery management systems 111, 121, 131, 141, 151 and 161 of a plurality of battery packs 11 to 16, and a master battery management system 10 connected to the slave battery management systems 111, 121, 131, 141, 151 and 161 by wireless communication, and two relays 17 and 18. Hereinafter, the slave battery management system is referred to as a slave BMS (battery management system), and the master battery management system is referred to as a master BMS.

[0037] The master BMS 10 generates relay control signals RCS1 and RCS2 to control opening and closing of the relays 17 and 18 , and the relays 17 and 18 are closed by the relay control signals RCS1 and RCS2 of the on level.

[0038] Figure 2 It is shown Figure 1A view of one of the multiple battery packs shown.

[0039] Figure 2 The structure of the illustrated battery pack 11 may be the same as the structures of the remaining battery packs 12 to 16 .

[0040] like Figure 2 As shown, the battery pack 11 includes a plurality of battery cells 11_1 to 11_n (n is a natural number of 2 or more) connected in series, a slave BMS 111 , a current sensor 112 , a wireless communication module 113 , and a relay 114 .

[0041] The current sensor 112 may detect current flowing through the battery pack 11 (hereinafter, battery pack current) and transmit a current detection signal SC indicating the detected battery pack current to the slave BMS 111. Figure 2 In the embodiment, the current sensor 112 is connected between the negative electrode of the battery pack 11 and the output terminal (-) of the battery pack 11, but Figure 1 Unlike that shown in , it can be connected between the positive electrode of the battery pack 11 and the output terminal (+) of the battery pack 11.

[0042] The slave BMS 111 measures the cell voltages of the plurality of battery cells 11_1 to 11_n, and transmits information indicating the measurement results to the master BMS 10 through the wireless communication module 113. The slave BMS 111 may measure the battery pack voltage of two terminal voltages of the battery pack 11, the temperature of the battery pack 11 (hereinafter, the battery pack temperature), etc., and transmits the plurality of battery cell voltages together with at least one of the battery pack current, the battery pack voltage, and the temperature of the battery pack 11 to the master BMS 10 through the wireless communication module 113.

[0043] The relay 114 is connected between the output terminal (+) of the battery pack and the positive electrode of the battery pack 11, and is opened or closed according to the relay control signal RCS3 from the BMS 111. The relay 114 is closed according to the relay control signal RCS3 of the on level, and is opened according to the relay control signal RCS3 of the off level.

[0044] Figure 3 is a view illustrating a master BMS according to an exemplary embodiment.

[0045] The master BMS 10 includes a control module 101 and a wireless communication module 102. The master BMS receives information of at least one of a battery pack current, a battery pack voltage, and a battery pack temperature together with a plurality of battery cell voltages 10 from each of a plurality of slave BMSs 111, 121, 131, 141, 151, and 161. The information received through the wireless communication module 102 is transmitted to the control module 101.

[0046] The CAN bus line 5 is connected between the control module 101 and the electronic control units ECU1 and ECU2, so that the control module 101 and the electronic control units ECU1 and ECU2 can send and receive necessary information through CAN communication. For example, the electronic control unit ECU1 can send a signal requesting power supply to the control module 101 through CAN communication so as to receive the power required to drive the vehicle. In addition, the control module 101 can send charging control information to the electronic control unit ECU1 through CAN communication to control charging. In addition, the control module 101 requests information about the current position of the vehicle and the current road condition of the vehicle position (hereinafter referred to as road condition information) from the electronic control unit ECU2, and the current vehicle position and road condition information from the electronic control unit ECU2 via CAN communication can be sent to the control module 101 via CAN communication. The road condition information may include information indicating whether the road at the current position of the vehicle corresponds to a highway, an uphill road, a downhill road, a parking lot, a child protection area, near the destination, a low speed limit section, etc.

[0047] The control module 101 can adjust the fault confirmation time for determining whether a wireless communication fault occurs differently based on the road condition information. For example, the fault confirmation time is set to a first interval for road conditions that may cause overvoltage / low voltage of the battery cell, and the fault confirmation time is set to a second interval for road conditions that do not affect the battery cell. In this case, the first interval is shorter than the second interval. That is, under road conditions where the battery cell does not cause overvoltage or low voltage, the control module 101 can set the fault confirmation time longer to ensure the RF communication recovery time without entering the safety mode. Then, frequent safety mode entry can be prevented.

[0048] The control module 101 may control the charging operation and the discharging operation of each of the plurality of battery packs 11 to 16 based on the plurality of cell voltages, the battery pack current, and the battery pack temperature received from each of the plurality of slave BMSs 111, 121, 131, 141, 151, and 161. For example, the control module 101 may control the disconnection of the relay 114 based on the plurality of cell voltages received during charging or discharging, and transmit a control signal for disconnecting the relay 114 of a specific battery pack 11 to 16 among the plurality of battery packs 11 to 16 to the slave BMS.

[0049] In addition, the control module 101 may detect a cell in which cell balancing is requested based on the plurality of received cell voltages, and transmit a signal for controlling cell balancing to a slave BMS of a battery pack including the corresponding cell.

[0050] The control module 101 may determine whether a wireless communication failure has occurred based on a signal received through the wireless communication module 102. The method for determining a wireless communication failure may be implemented by one of various known techniques. For example, if the wireless communication failure is maintained during the fault confirmation time, the control module 101 places the master BMS 10 in a safety mode. Depending on the safety mode, the control module 101 generates a relay control signal to disconnect the relays 17 and 18.

[0051] In the following, reference Figure 4 A fault confirmation time control method according to an exemplary embodiment is described.

[0052] Figure 4 is a view illustrating a fault confirmation time control method according to an exemplary embodiment.

[0053] The control module 101 determines whether wireless communication between the master BMS 10 and at least one of the plurality of slave BMSs 111, 121, 131, 141, 151, and 161 has failed (S10). As a result of the determination of step S1, if wireless communication failure has not occurred, the control module 101 may periodically repeat step (S1).

[0054] As a result of the determination in step ( S1 ), if a wireless communication failure occurs, the control module 101 requests information on a road condition in which the vehicle is currently located from the electronic control unit ECU2 to receive corresponding information ( S2 ).

[0055] The control module 101 determines whether it is possible to cause overvoltage / low voltage of a cell on the road based on the road condition information that the vehicle is currently in (S3). For example, if the road condition information is any one of high speed, uphill, downhill, etc., the control module 101 determines that the current position of the vehicle is on a road that can cause overvoltage / low voltage.

[0056] As a result of the determination in step (S3), if the current position of the vehicle is on a road that can cause overvoltage / low voltage of a cell, the control module 101 sets the fault confirmation time to the first interval T1 (S4). As a result of the determination in step (S3), if the current position of the vehicle is not on a road that can cause overvoltage / low voltage of a cell, the control module 101 sets the fault confirmation time to the second interval T2 (S5). The second interval is longer than the first interval.

[0057] After step ( S4 ), the control module 101 determines whether the wireless communication failure is maintained ( S6 ).

[0058] As a result of the determination of step (S6), if the wireless communication failure is maintained, the control module 101 derives a wireless communication failure interval from the time when the wireless communication failure occurred to the current time (S7). The control module 101 may count the passage of time.

[0059] The control module 101 compares the wireless communication failure section with the failure confirmation time T1 predetermined in step ( S4 ) ( S8 ).

[0060] As a result of the determination of step (S8), if the wireless communication fault section reaches the fault confirmation time T1, the control module 101 enters the safety mode (S9). Depending on the safety mode, the control module 101 may turn off the relay.

[0061] As a result of the determination in step ( S8 ), if the wireless communication failure section has not reached the failure confirmation time T1 , the control module 101 repeats from step ( S6 ).

[0062] As a result of the determination of step ( S6 ), if the wireless communication failure is not maintained, the control module 101 may periodically repeat step ( S1 ) again.

[0063] After step ( S5 ), the control module 101 determines whether the wireless communication failure is maintained ( S10 ).

[0064] As a result of the determination of step (S10), if the wireless communication failure is maintained, the control module 101 derives a wireless communication failure interval from the time when the wireless communication failure occurs to the current time (S11). The control module 101 may count the passage of time.

[0065] The control module 101 compares the wireless communication failure section with the failure confirmation time T2 predetermined in step (S5) (S12).

[0066] As a result of the determination of step (S12), if the wireless communication fault section reaches the fault confirmation time T2, the control module 101 enters the safety mode (S13). Depending on the safety mode, the control module 101 may turn off the relay.

[0067] As a result of the determination in step ( S12 ), if the wireless communication failure section has not reached the failure confirmation time T2 , the control module 101 repeats from step ( S10 ).

[0068] As a result of the determination of step ( S10 ), if the wireless communication failure is not maintained, the control module 101 may periodically repeat step ( S1 ) again.

[0069] Therefore, according to an exemplary embodiment, by differently controlling a fault confirmation time for determining whether a wireless communication fault occurs based on a current position of a vehicle, the stability and marketability of a battery system may be improved.

[0070] While the invention has been described in conjunction with what are presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A management method for a battery system, the battery system comprising a plurality of battery packs, a plurality of slave battery management systems, and a master battery management system connected to the slave battery management systems via wireless communication, the management method comprising: determining whether a wireless communication failure occurs between the master device and at least one of the plurality of slave devices; If the wireless communication failure occurs, receiving road condition information on which the vehicle equipped with the battery system is currently located; determining whether the vehicle is located on a road that can cause cell overvoltage / low voltage based on the road condition information; If the current position of the vehicle is located on a road that can cause overvoltage / low voltage of the cell, setting a first fault confirmation time; If the current position of the vehicle is not located on a road that can cause overvoltage / low voltage of the cell, setting a second fault confirmation time; as well as If the wireless communication failure interval from the time when the wireless communication failure occurs to the current time reaches the first failure confirmation time or the second failure confirmation time, enter the safety mode, The second fault confirmation time is longer than the first fault confirmation time.

2. The battery system management method according to claim 1, wherein: Determining whether the vehicle is located on a road that can cause overvoltage / low voltage of the cell based on the road condition information includes When the road condition information is any one of a highway, an uphill road, and a downhill road, it is determined that the current position of the vehicle is located on a road that can cause overvoltage / lowvoltage of the cell.

3. The battery system management method according to claim 1, further comprising: A wireless communication failure interval from the time when the wireless communication failure occurs to the current time is derived.

4. The battery system management method according to claim 1, further comprising: When the current position of the vehicle is located on a road that can cause the cell overvoltage / low voltage, if the wireless communication failure section has not reached the first failure confirmation time, it is determined whether the wireless communication failure is maintained.

5. The battery system management method according to claim 1, further comprising: When the current position of the vehicle is not located on a road that can cause the cell overvoltage / low voltage, if the wireless communication failure section has not reached the second failure confirmation time, it is determined whether the wireless communication failure is maintained.

6. The battery system management method according to claim 1, further comprising: A relay between the vehicle and the battery system is opened depending on the safety mode.

7. A battery system, comprising: A battery pack, the battery pack comprising a plurality of battery cells and a slave battery management system; A master battery management system, the master battery management system being connected to the slave battery management system via wireless communication; as well as at least one relay connected between the vehicle and the battery pack, Wherein, if a fault occurs in the wireless communication with the slave battery management system, the master battery management system receives the road condition information of the vehicle's current location, determines whether the vehicle is located on a road that can cause single cell overvoltage / low voltage based on the road condition information, sets a first fault confirmation time if the vehicle's current location is located on a road that can cause single cell overvoltage / low voltage, sets a second fault confirmation time if the vehicle's current location is not located on a road that can cause single cell overvoltage / low voltage, and enters a safety mode if the wireless communication fault interval from the time when the wireless communication fault occurs to the current time reaches the first fault confirmation time or the second fault confirmation time, and The second fault confirmation time is longer than the first fault confirmation time.

8. The battery system according to claim 7, wherein When the road condition information is any one of high speed, uphill or downhill, the master battery management system determines that the current position of the vehicle is located on a road that can cause overvoltage / low voltage of the cell.

9. The battery system according to claim 7, wherein The master battery management system derives a wireless communication failure interval from a time when the wireless communication failure occurs to the current time.

10. The battery system according to claim 7, wherein When the current position of the vehicle is located on a road that can cause overvoltage / low voltage of the cell, if the wireless communication fault interval does not reach the first fault confirmation time, the master battery management system determines whether the wireless communication fault is maintained.

11. The battery system according to claim 7, wherein When the current position of the vehicle is not located on a road that can cause the cell overvoltage / low voltage, if the wireless communication fault interval does not reach the second fault confirmation time, the master battery management system determines whether the wireless communication fault is maintained.

12. The battery system according to claim 7, wherein The master battery management system disconnects at least one relay depending on the safety mode.

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