Method and system for battery management of electric mobility

Abstract

A battery management method and a battery management system for an electric vehicle are disclosed. A battery management method for an electric vehicle according to one embodiment of the present invention is characterized by comprising: receiving State of Charge (SOC) information of a plurality of batteries mounted on the electric vehicle; determining whether the difference between the SOC of a first battery with the highest SOC and a second battery with the lowest SOC among the plurality of batteries exceeds a predetermined threshold; and controlling the power flow of at least one converter among a plurality of converters connected to the plurality of batteries to control the charging or discharging of at least one of the plurality of batteries.

Description

Technology Field

[0001] The present invention relates to a battery management method and system for electric mobility means. More specifically, it relates to a battery management method and system for efficiently balancing the SOC of a battery in an electric mobility means equipped with a plurality of batteries. Background Technology

[0002] Electric mobility devices, such as electric bicycles or e-cargo vehicles, use electricity to power motors to assist human power or drive the vehicle. Since these electric vehicles utilize electrical energy, a battery capable of supplying power is essential.

[0003] While a single battery (battery pack) may be used to power an electric vehicle, multiple batteries can be used to power the electric vehicle for energy efficiency.

[0004] Meanwhile, in the case of electric vehicles equipped with multiple batteries, the State of Charge (SOC) of each battery may differ as the vehicle is driven. Alternatively, batteries with different SOCs may be installed in the vehicle from the start.

[0005] In this regard, there may be cases where it becomes difficult to drive an electric vehicle normally due to the level of SOC of at least one of the multiple batteries, and in such cases, the driving range may be reduced even though the SOC of the other batteries remains sufficient.

[0006] In addition, as mentioned above, if the SOC of some batteries is insufficient and driving is performed using only the motor connected to the battery with sufficient remaining SOC, a problem may occur in which the maximum torque and output during driving are reduced compared to when all batteries are used.

[0007] Therefore, in electric mobility systems utilizing multiple batteries, there is a need for a battery management method and a battery management system for electric mobility to balance the State of Charge (SOC). The problem to be solved

[0008] The present invention aims to solve the problems of the aforementioned prior art and to provide a battery management method and system for improving the driving performance of an electric vehicle using multiple batteries by balancing the State of Charge (SOC) of multiple batteries.

[0009] In addition, the present invention aims to provide a battery management method and system that can improve the output and driving time of an electric vehicle by performing SOC balancing more quickly and effectively when balancing the SOC of a plurality of batteries.

[0010] However, the technical problems that the embodiments of the present invention aim to solve are not limited to the technical problems described above, and other technical problems may exist. means of solving the problem

[0011] As a technical means for achieving the above-mentioned technical problem, a battery management method for an electric vehicle according to one embodiment of the present invention comprises: receiving State of Charge (SOC) information of a plurality of batteries mounted on the electric vehicle; determining whether the difference between the SOC of a first battery with the highest SOC and a second battery with the lowest SOC among the plurality of batteries exceeds a predetermined threshold; and controlling the power flow of at least one converter among a plurality of converters connected to the plurality of batteries to control the charging or discharging of at least one of the plurality of batteries.

[0012] In addition, the plurality of converters are bidirectional converters, and the plurality of converters may include a first bidirectional converter connected to the first battery and a second bidirectional converter connected to the second battery.

[0013] In addition, when the difference between the SOC of the first battery and the SOC of the second battery exceeds the predetermined threshold value, the step of controlling the charging or discharging of at least one of the plurality of batteries can control the charging or discharging of the first battery and the second battery by controlling the power flow of the first bidirectional converter and the second bidirectional converter.

[0014] In addition, when the difference between the SOC of the first battery and the SOC of the second battery does not exceed the predetermined threshold value, the step of controlling the charging or discharging of at least one of the plurality of batteries may be to control only the power flow of the second bidirectional converter until the SOC of the first battery and the SOC of the second battery become the same, thereby supplying power from the generator to the second battery to charge the second battery.

[0015] Additionally, the step of controlling the charging or discharging of at least one of the plurality of batteries may be performed by controlling the power flow of the first bidirectional converter to supply power from the first battery to the generator until the SOC of the first battery and the SOC of the second battery become the same, thereby discharging the first battery, and by controlling the power flow of the second bidirectional converter to supply power from the generator to the second battery, thereby charging the second battery.

[0016] Additionally, the step of controlling the charging or discharging of at least one of the plurality of batteries may be performed by controlling the power flow of the first bidirectional converter to supply power from the first battery to the generator until the difference between the SOC of the first battery and the SOC of the second battery becomes less than or equal to the predetermined threshold value, thereby discharging the first battery, and by controlling the power flow of the second bidirectional converter to supply power from the generator to the second battery, thereby charging the second battery.

[0017] In addition, the battery management method of the electric mobility means further includes, after the step of controlling the charging or discharging of at least one of the plurality of batteries, a step of determining whether the SOC of the plurality of batteries is the same, and may control the charging or discharging of at least one of the plurality of batteries until the SOC of the plurality of batteries becomes the same.

[0018] In addition, the battery management method of the electric mobility means may further include a step of determining whether the system is normal after a step of determining whether the SOC of the plurality of batteries is all the same.

[0019] In addition, the step of determining whether the system is normal may determine that the system is abnormal if the current generated by the generator is an overcurrent, if the voltage of at least one of the plurality of batteries is outside the range of the system's usable voltage, or if the components of the system are outside the operating temperature range.

[0020] In addition, if the above system is determined to be abnormal, a warning may be given to the driver that the system is abnormal.

[0021] A battery management system for an electric vehicle according to an embodiment of the present invention comprises: a generator that generates voltage by driving a pedal; a plurality of batteries mounted on the electric vehicle; a plurality of motors mounted on at least one of the front wheel and rear wheel of the electric vehicle to provide rotational force to the wheel; a plurality of converters for converting the voltage of the plurality of batteries; and a control unit for controlling the system, wherein the control unit receives State of Charge (SOC) information of the plurality of batteries, determines whether the difference between the SOC of a first battery with the highest SOC and a second battery with the lowest SOC among the plurality of batteries exceeds a predetermined threshold value, and controls the power flow of at least one converter among the plurality of converters to control the charging or discharging of at least one battery among the plurality of batteries.

[0022] In addition, the plurality of converters are bidirectional converters, and the plurality of converters may include a first bidirectional converter connected to the first battery and a second bidirectional converter connected to the second battery.

[0023] In addition, the control unit can control the charging or discharging of the first battery and the second battery by controlling the power flow of the first bidirectional converter and the second bidirectional converter when the difference between the SOC of the first battery and the SOC of the second battery exceeds the predetermined threshold value.

[0024] In addition, the control unit can charge the second battery by supplying power from the generator to the second battery when the difference between the SOC of the first battery and the SOC of the second battery does not exceed the predetermined threshold value, and by controlling only the power flow of the second bidirectional converter until the SOC of the first battery and the SOC of the second battery become the same.

[0025] Additionally, the control unit may control the power flow of the first bidirectional converter to supply power from the first battery to the generator until the SOC of the first battery and the SOC of the second battery become the same, thereby discharging the first battery, and control the power flow of the second bidirectional converter to supply power from the generator to the second battery, thereby charging the second battery.

[0026] Additionally, the control unit may control the power flow of the first bidirectional converter to supply power from the first battery to the generator to discharge the first battery until the difference between the SOC of the first battery and the SOC of the second battery becomes less than or equal to the predetermined threshold value, and control the power flow of the second bidirectional converter to supply power from the generator to the second battery to charge the second battery.

[0027] In addition, the control unit can control the charging or discharging of at least one of the plurality of batteries until the SOC of all the plurality of batteries becomes the same.

[0028] In addition, when the SOC of the plurality of batteries becomes the same, the control unit can determine whether the system is normal.

[0029] In addition, the control unit may determine that the system is abnormal if the current generated by the generator is an overcurrent, if the voltage of at least one of the plurality of batteries exceeds the range of the system's usable voltage, or if the component of the system exceeds the operating temperature range.

[0030] In addition, the battery management system of the electric mobility means further includes an interface including a display, and if the system is determined to be abnormal, the control unit may display a warning that the system is abnormal on the display of the interface.

[0031] The means for solving the problem described above are merely exemplary and should not be interpreted as intended to limit the present invention. In addition to the exemplary embodiments described above, additional embodiments may exist in the drawings and the detailed description of the invention. Effects of the invention

[0032] According to the means for solving the problem of the present invention described above, a battery management method and system for an electric vehicle can be provided that can improve the driving performance of an electric vehicle by controlling the balance of the SOC of a plurality of batteries mounted on the electric vehicle.

[0033] In addition, according to the means for solving the problem of the present invention described above, a battery management method and system for an electric mobility means can be provided that can perform battery balancing quickly and effectively by controlling the power flow of a plurality of converters connected to a plurality of batteries to perform battery SOC balancing.

[0034] However, the effects obtainable from this invention are not limited to those described above, and other effects may exist. Brief explanation of the drawing

[0035] FIG. 1 is a flowchart illustrating a battery management method for an electric mobility means according to an embodiment of the present invention. FIG. 2 is a flowchart specifically illustrating a battery management method for an electric mobility means according to the first embodiment of the present invention. FIG. 3 is a flowchart specifically illustrating a battery management method for an electric mobility means according to a second embodiment of the present invention. FIGS. 4(a) and (b) are schematic diagrams illustrating a system of an embodiment having two batteries in a battery management system for an electric mobility means according to an embodiment of the present invention. FIGS. 5(a) and (b) are schematic diagrams illustrating a system of an embodiment having three or more batteries in a battery management system for an electric mobility means according to an embodiment of the present invention. FIG. 6 (a) and (b) are experimental examples of a battery management method for an electric vehicle according to the first embodiment of the present invention, in an embodiment in which the battery management system of an electric vehicle according to the present invention has two batteries. FIG. 7 (a) and (b) are experimental examples of a battery management method for an electric vehicle according to the second embodiment of the present invention, in an embodiment in which the battery management system of an electric vehicle according to the present invention has two batteries. FIG. 8 (a) and (b) are experimental examples of a battery management method for an electric vehicle according to the first embodiment of the present invention, in an embodiment in which the battery management system of an electric vehicle according to the present invention has three batteries. FIG. 9 (a) and (b) are experimental examples of a battery management method for an electric vehicle according to the second embodiment of the present invention, in an embodiment in which the battery management system of an electric vehicle according to the present invention has three batteries. Specific details for implementing the invention

[0036] Embodiments of the present invention are described below with reference to the attached drawings to enable those skilled in the art to easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification are denoted by similar reference numerals.

[0037] Throughout this specification, when a part is described as being "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "electrically connected" or "indirectly connected" with other elements interposed between them.

[0038] Throughout the entire specification, when a component is described as being located "on," "on top," "on top," "under," "on bottom," or "on bottom" of another component, this includes not only cases where the component is in contact with the other component but also cases where another component exists between the two components.

[0039] Throughout this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0040] The present invention relates to a battery management method and a battery management system for improving the driving performance of an electric vehicle equipped with multiple batteries by efficiently balancing the SOC of the batteries.

[0041] FIG. 1 is a flowchart illustrating a battery management method for an electric mobility means according to an embodiment of the present invention.

[0042] In an embodiment of the present invention, the battery system of an electric vehicle may include a plurality of batteries (battery packs). There may be a variation in State of Charge (SOC), which indicates the degree of charge, among these plurality of batteries.

[0043] In cases where there is a difference in SOC between batteries and some batteries are in a state where driving is difficult, even if driving is performed using only the motor connected to the battery with sufficient remaining SOC, a problem may arise where the maximum torque and output during driving are reduced compared to when all batteries are used.

[0044] Therefore, the present invention proposes a method for managing multiple batteries to reduce deviations in SOC and achieve balance.

[0045] Referring specifically to FIG. 1, the battery management method of an electric vehicle according to an embodiment of the present invention may include a step (S100) of collecting SOC information of a plurality of batteries mounted on the electric vehicle. The SOC information of the batteries may be collected from sensors provided in each of the plurality of batteries.

[0046] Next, the battery management method for an electric mobility means according to an embodiment of the present invention may include a step (S200) of determining whether the difference between the SOC of the battery with the highest SOC (hereinafter referred to as the 'first battery') and the battery with the lowest SOC (hereinafter referred to as the 'second battery') among a plurality of batteries exceeds a predetermined threshold value.

[0047] In addition, the battery management method of an electric vehicle according to an embodiment of the present invention may include a step (S300, S400) of controlling the power flow of at least one converter among a plurality of converters connected to a plurality of batteries to control the charging or discharging of at least one of the plurality of batteries.

[0048] Here, it is preferable that the plurality of converters are bidirectional converters. A bidirectional converter is a power conversion device connected to a battery, a generator (ePedal), and / or a motor, which allows power flow to be controlled in various ways.

[0049] For example, the bidirectional converter can be controlled to charge the battery by controlling the power flow from the generator (ePedal) to the battery, or to discharge the battery by controlling the power flow from the battery to the generator. Additionally, the bidirectional converter can control bidirectional power flow between the generator and the motor, or bidirectional power flow between multiple batteries.

[0050] Meanwhile, a plurality of bidirectional converters may include a bidirectional converter connected to the battery with the highest SOC (first battery) (hereinafter referred to as the 'first bidirectional converter') and a bidirectional converter connected to the battery with the lowest SOC (second battery) (hereinafter referred to as the 'second bidirectional converter').

[0051] In addition, the step of controlling the charging or discharging of at least one of the plurality of batteries may control the charging or discharging of the first battery and the second battery by controlling the power flow of the first bidirectional converter and the second bidirectional converter when the difference in SOC exceeds a predetermined threshold value.

[0052] Specifically, power flow of the first bidirectional converter can be controlled to supply power from the first battery to the generator to discharge the first battery, and power flow of the second bidirectional converter can be controlled to supply power from the generator to the second battery to charge the second battery (S300).

[0053] In this way, by performing discharge control on the battery with the highest SOC and charging control on the battery with the lowest SOC, the SOC of the battery with the highest SOC and the battery with the lowest SOC can be quickly and effectively balanced.

[0054] Meanwhile, when the difference in SOC is below a predetermined threshold (when it does not exceed a predetermined threshold), only the second bidirectional converter connected to the second battery with the lowest SOC is operated to control the power flow from the generator to the battery, thereby charging the second battery (S400).

[0055] Subsequently, it is determined whether the SOCs of the multiple batteries are all the same (S500), and the power flow control as described above can be performed until the SOCs of the multiple batteries are all the same. If the SOCs of the multiple batteries are not all the same ('No' in S500), the process returns to the step of collecting SOC information of the multiple batteries (S100) and repeats the charging or discharging control of the batteries until the SOCs of the multiple batteries are all the same, and when the SOCs of the multiple batteries are all the same ('Yes' in S500), the control can be terminated.

[0056] FIG. 2 is a flowchart specifically illustrating a battery management method for an electric mobility means according to a first embodiment of the present invention, and FIG. 3 is a flowchart specifically illustrating a battery management method for an electric mobility means according to a second embodiment of the present invention.

[0057] As shown in FIG. 2, according to the battery management method of an electric mobility means according to the first embodiment of the present invention, when the difference between the SOC of the first battery and the SOC of the second battery exceeds a predetermined threshold value, the power flow of the first bidirectional converter can be controlled to discharge the first battery until the SOC of the first battery and the SOC of the second battery become equal (i.e., until the difference in SOC becomes 0), and the power flow of the second bidirectional converter can be controlled to charge the second battery (S310).

[0058] In this way, by controlling the discharge of the first battery and the charge of the second battery, an effect can be achieved to balance the SOC of the first battery and the second battery more quickly.

[0059] Meanwhile, as shown in FIG. 3, according to the battery management method of an electric mobility means according to the second embodiment of the present invention, when the difference between the SOC of the first battery and the SOC of the second battery exceeds a predetermined threshold, the power flow of the first bidirectional converter can be controlled to discharge the first battery until the difference between the SOC of the first battery and the SOC of the second battery becomes less than or equal to a predetermined threshold (i.e., until the difference in SOC reaches a predetermined threshold), and the power flow of the second bidirectional converter can be controlled to charge the second battery (S320).

[0060] In this case, a significant effect can be achieved in that the difference in SOC between the first battery and the second battery is reduced first through discharge control of the first battery and charge control of the second battery, and then the SOC of multiple batteries is balanced when the SOC level of the battery is high through additional control.

[0061] Meanwhile, in the first and second embodiments, when the difference between the SOC of the first battery and the SOC of the second battery does not exceed a predetermined threshold (when the difference in SOC is less than or equal to a predetermined threshold), only charging control of the second battery may be performed until the SOCs of the first battery and the second battery become the same (S400).

[0062] As seen in FIG. 1, after performing charging and / or discharging control (S310, S320, S400) of the first battery and the second battery, it is determined whether the SOC of all batteries is the same (S500), and if they are not the same ('Yes' of S500), SOC balancing control of the batteries can be performed again.

[0063] Meanwhile, if the SOC of all batteries becomes the same by balancing control ('Yes' in S500), a system normality determination step (S600) for determining whether the system is normal may be additionally performed (see FIG. 2 and FIG. 3).

[0064] The determination of whether the system is normal is made by determining whether the system can operate normally through diagnosis of the system's components. For example, the system may be determined to be abnormal if the current generated by the generator is an overcurrent, if the voltage of at least one of the multiple batteries is outside the range of the system's usable voltage, or if the system's components are outside the operating temperature range.

[0065] As shown in FIGS. 2 and 3, if the system is determined to be abnormal based on the determination of whether the system is normal ('No' of S600), the battery management system cannot operate normally, so a warning is issued to the driver indicating that the system is abnormal, or the system may not operate (Fail). On the other hand, if the system is determined to be normal ('Yes' of S600), control may be terminated.

[0066] FIGS. 4 and 5 are schematic diagrams illustrating various embodiments of a battery management system according to an embodiment of the present invention.

[0067] In a battery management system according to an embodiment of the present invention, the generator, also known as ePedal, provides the driver with a pedaling sensation and a driving sensation, and at the same time, can play the role of converting kinetic energy into electrical energy by the driver rotating the pedal.

[0068] The battery serves to supply power to devices such as generators, motors, and interfaces, and by connecting and mounting multiple batteries, the driving range and output of electric vehicles can be improved.

[0069] In addition, the motor plays the role of driving the wheels of the electric vehicle using electrical energy, and can also charge the battery with energy generated during braking through the motor's regenerative braking function.

[0070] A converter is a power conversion device that controls power flow, and a bidirectional converter used as a preferred embodiment enables various power flows, thereby controlling the charging and discharging of multiple batteries.

[0071] FIGS. 4(a) and (b) are schematic diagrams illustrating a system of an embodiment having two batteries in a battery management system for an electric mobility means according to an embodiment of the present invention.

[0072] Referring to FIG. 4(a), the battery management system (100) of an electric mobility means according to an embodiment of the present invention may include a generator (110) that generates voltage by driving a pedal. Additionally, the battery management system (100) may include two batteries (121, 122) and two converters (141, 142) connected to correspond one-to-one with the batteries. Additionally, two motors (131, 132) may be connected to correspond to the two batteries (121, 122) and the two converters (141, 142).

[0073] Additionally, the generator (110) may include a control unit (150) that controls the system. Meanwhile, in the embodiments of FIGS. 4 and 5, the control unit is exemplified as being included within the generator, but the present invention is not limited thereto, and the control unit may be provided separately from the generator.

[0074] Meanwhile, according to the battery management method of the electric vehicle described above, the control unit (150) collects SOC information of the batteries (121, 122), determines whether the difference between the SOC of the battery with the higher SOC and the battery with the lower SOC among the two batteries (121, 122) exceeds a predetermined threshold, and then controls the power flow of at least one of the converters (141, 142) so that the SOCs of the two batteries (121, 122) become the same.

[0075] Additionally, the battery management system (100) of an electric mobility means according to an embodiment of the present invention may include an interface (160). For example, the interface (160) may be a Human Machine Interface (HMI) including a display.

[0076] Meanwhile, to determine whether the battery management system is functioning normally, the current state of the generator (110), the voltage state of the battery (121, 122), and / or the temperature of each component (generator (110), battery (121, 122), motor (131, 132), converter (141, 142)) can be monitored. For example, the current of the generator can be detected by a generator current sensor, the voltage of the battery can be detected by a battery voltage sensor, and the temperature of each component of the system can be detected by at least one temperature sensor.

[0077] Accordingly, if the system is determined to be abnormal, such as when the current generated by the generator (110) is an overcurrent, when the voltage of at least one of the multiple batteries (121, 122) is outside the range of the system's usable voltage and is undervolted or overvolted, or when the temperature of a component of the system is outside the range of the operating temperature, a warning can be given to the driver through the display of the interface (160).

[0078] In addition, in addition to a visual warning through the display of the interface (160), an auditory warning may also be provided to inform the driver of the abnormal state of the system, and if the system cannot be operated due to the abnormal state of the system, the system may be prevented from operating along with providing a warning.

[0079] The battery management system (200) of an electric mobility means according to an embodiment of the present invention shown in FIG. 4(b) is equipped with a generator (210), a control unit (250), and an interface (260), and is equipped with two batteries (221, 222) and two converters (241, 242) as in FIG. 4(a), but is a different embodiment in that the number of motors (231, 232, 233) is three.

[0080] That is, the embodiment of FIG. 4(b) represents a case in which a plurality (2) of motors (231, 232) are connected to one of the plurality of converters (241, 242). This is a case in which at least one of the front or rear wheels of the electric vehicle has a plurality (2), and the two motors (231, 232) connected to the one converter (241) may be motors provided on each of the two wheels on one side of the front or rear wheels of the electric vehicle.

[0081] In this way, by providing a plurality of motors (231, 232), whose power flow is controlled by a single converter (241), on one side where a plurality of wheels are provided, either the front wheel or the rear wheel, the power flow for the plurality of motors (231, 232) provided on one side of the front wheel or the rear wheel can be controlled collectively.

[0082] FIGS. 5(a) and (b) are schematic diagrams illustrating a system of an embodiment having three or more batteries in a battery management system for an electric mobility means according to an embodiment of the present invention.

[0083] Referring to FIG. 5(a), the battery management system of an electric vehicle according to an embodiment of the present invention may be equipped with three batteries (321, 322, 323) in addition to the configuration of (300), a generator (310), a control unit (350), and an interface (360).

[0084] In addition, three converters (341, 342, 343) may be provided to correspond one-to-one with three batteries (321, 322, 323). In addition, three motors (331, 332, 333) may each be connected to a battery and a converter.

[0085] In an embodiment in which three batteries are provided in this manner, a battery management method for an electric vehicle can be implemented so that the SOC of the three batteries (321, 322, 323) is the same.

[0086] That is, according to the battery management method described above, the control unit (350) collects SOC information of three batteries (321, 322, 323), determines whether the difference between the SOC of the battery with the highest SOC and the battery with the lowest SOC exceeds a predetermined threshold, and then controls the power flow of at least one of the converters (341, 342, 343) so that the SOCs of the three batteries (321, 322, 323) become the same.

[0087] Referring to FIG. 5(b), the battery management system of an electric vehicle according to an embodiment of the present invention may be equipped with four batteries (421, 422, 423, 424) in addition to the configuration of (400), a generator (410), a control unit (450), and an interface (460).

[0088] In this embodiment, four converters (441, 442, 443, 444) may be provided to correspond one-to-one with four batteries (421, 422, 423, 424), and four motors (431, 432, 433, 434) may each be connected to the batteries and converters.

[0089] In the embodiment illustrated in FIG. 5(b) where four batteries are provided, the battery management method described above can be implemented so that the SOC of the four batteries (421, 422, 423, 424) is the same.

[0090] FIGS. 6 to 9 illustrate experimental examples of controlling the State of Charge (SOC) of a plurality of batteries in a battery management method for an electric vehicle according to an embodiment of the present invention. FIGS. 6 to 9 illustrate a predetermined threshold value for the difference between the SOC of the battery with the largest SOC and the SOC of the battery with the smallest SOC as 10%. However, the present invention is not limited thereto, and the predetermined threshold value may be set differently as needed.

[0091] FIGS. 6(a) and (b) are experimental examples of a battery management method for an electric vehicle according to the first embodiment of the present invention, in an embodiment in which the battery management system of an electric vehicle according to the present invention has two batteries. The experimental example may be an embodiment in which two batteries (BAT1, BAT2) are controlled in a system corresponding, for example, to FIG. 4(a) or (b).

[0092] Figure 6 (a) shows a case where the difference (20%) between the SOC (88%) of the battery with the highest SOC (BAT1) and the SOC (68%) of the battery with the lowest SOC (BAT2) among the two batteries exceeds a predetermined threshold (10%).

[0093] Since the difference in SOC between the battery with the highest SOC (BAT1) and the battery with the lowest SOC (BAT2) among the two batteries exceeds a predetermined threshold, power can be supplied from the generator (ePedal) to the battery (BAT2) with the lowest SOC to charge it. Meanwhile, in the case of the battery with the highest SOC (BAT1), power can be supplied from the battery (BAT1) to the generator (ePedal) to discharge it.

[0094] Here, according to the first embodiment of the present invention, charging and discharging are performed until the SOC of the two batteries becomes equal, so the SOC of the two batteries (BAT1, BAT2) can be balanced at the 78% point where the SOC of the two batteries becomes equal.

[0095] Figure 6 (b) shows a case where the difference in SOC (8%) between the battery with the highest SOC (BAT1) and the battery with the lowest SOC (BAT2) among the two batteries does not exceed a predetermined threshold (10%).

[0096] In this case, since the difference in SOC does not exceed a predetermined threshold, discharge from the battery with the highest SOC (BAT1) is not performed, and only charging from the generator (ePedal) to the battery with the lowest SOC (BAT2) can be performed. Meanwhile, since charging of the battery (BAT2) is performed until the SOCs of the two batteries become equal, the SOCs of the two batteries can be balanced at the 84% point, which corresponds to the SOC of the battery with the highest SOC (BAT1).

[0097] FIG. 7 (a) and (b) are experimental examples of a battery management method for an electric vehicle according to the second embodiment of the present invention, in an embodiment in which the battery management system of an electric vehicle according to the present invention has two batteries.

[0098] Figure 7 (a) shows a case where, as in Figure 6 (a), the SOC of the battery with the highest SOC (BAT1) among the two batteries is 88%, and the SOC of the battery with the lowest SOC (BAT2) is 68%.

[0099] Since the difference in SOC (20%) between the two batteries exceeds a predetermined threshold (10%), discharge control from the battery with the highest SOC (BAT1) to the generator and charge control from the generator to the battery with the lowest SOC (BAT2) can be performed.

[0100] However, unlike the first embodiment, the discharge and charge control is performed only until the difference in SOC of the two batteries becomes less than or equal to a predetermined threshold value (10%), so the first control may be terminated at the point where the difference in SOC reaches a predetermined threshold value (10%).

[0101] That is, discharge and charge control can be terminated when the battery with the highest SOC (BAT1) is discharged until its SOC reaches 83%, and the battery with the lowest SOC (BAT2) is charged until its SOC reaches 73%.

[0102] Meanwhile, since the SOCs of the two batteries (BAT1, BAT2) are not the same after the first control, a second control can be performed until the SOCs become the same. In the second control, since the difference between the SOCs of the two batteries is below a predetermined threshold (10%), only the charging control for the battery with the lowest SOC (BAT2) can be performed.

[0103] Therefore, through secondary control, the SOCs of the two batteries can be balanced at the 83% point, which is the SOC of the battery with the highest SOC (BAT1).

[0104] That is, compared to the experimental example according to the first embodiment (Fig. 6(a)), by performing balancing control one additional time, the effect of balancing the SOC at a higher level (78% -> 83%) can be achieved.

[0105] Figure 7(b) is a case where the difference in SOC (8%) between the battery with the highest SOC (BAT1) and the battery with the lowest SOC (BAT2) among the two batteries does not exceed a predetermined threshold value (10%). In this case, since only charging control is performed for the battery with the lowest SOC (BAT2), the same result as the experimental example of the first embodiment (Figure 6(b)) is obtained.

[0106] FIGS. 8(a) and (b) are experimental examples of a battery management method for an electric vehicle according to the first embodiment of the present invention, in an embodiment in which the battery management system of an electric vehicle according to the present invention has three batteries. This experimental example may be a case in which three batteries (BAT1, BAT2, BAT3) are controlled in a system corresponding to, for example, FIG. 5(a).

[0107] In the experimental example of FIG. 8 (a), the difference (12%) between the SOC (84%) of the battery with the highest SOC (BAT1) and the SOC (72%) of the battery with the lowest SOC (BAT3) among the three batteries exceeds a predetermined threshold value (10%).

[0108] In this case, since the difference between the battery with the highest SOC (BAT1) and the battery with the lowest SOC (BAT3) among the three batteries exceeds a predetermined threshold, in the case of the battery with the lowest SOC (BAT3), power can be supplied from the generator (ePedal) to the battery (BAT3) to charge it. Meanwhile, in the case of the battery with the highest SOC (BAT1), power can be supplied from the battery (BAT1) to the generator (ePedal) to discharge it.

[0109] Here, according to the first embodiment of the present invention, charging and discharging are performed until the SOC of the two batteries (BAT1, BAT3) becomes equal, so in the first control, the SOC of the two batteries (BAT1, BAT3) can be balanced at the 78% point where the SOC of the two batteries (BAT1, BAT3) becomes equal.

[0110] Meanwhile, in the case of three batteries, since the battery management method according to the embodiment of the present invention is performed until the SOC of the three batteries (BAT1, BAT2, BAT3) becomes the same, even if the first control is terminated through the control according to the first embodiment, additional control (second control) is performed unless the SOC of the other battery (BAT2), other than the battery with the highest SOC (BAT1) and the battery with the lowest SOC (BAT3), is the same as the SOC of the two batteries (BAT1, BAT3).

[0111] In this embodiment, in the second control, the battery with the highest SOC is BAT2 (SOC 80%), so the difference between the SOC (80%) of the battery with the highest SOC (BAT2) and the SOC (78%) of the batteries with the lowest SOC (BAT1, BAT3) becomes less than or equal to a predetermined threshold value (10%).

[0112] Therefore, in the secondary control, only charging control is performed from the generator to the battery with the lowest SOC (BAT1, BAT3), and the SOC of the three batteries can be balanced at the 80% point where the SOC of all batteries (BAT1, BAT2, BAT3) becomes equal.

[0113] Experimental example of Fig. 8(b) shows a case where the difference (8%) between the SOC (82%) of the battery with the highest SOC (BAT1) and the SOC (74%) of the battery with the lowest SOC (BAT3) among the three batteries is less than or equal to a predetermined threshold value (10%).

[0114] In this case, since the difference in SOC does not exceed a predetermined threshold, discharge from the battery with the highest SOC (BAT1) is not performed, and power is supplied from the generator (ePedal) to the battery with the lowest SOC (BAT3), so only charging of the battery (BAT3) can be performed. Meanwhile, since charging is performed until the SOCs of the two batteries (BAT1, BAT3) become equal, in the first control, the SOCs of the two batteries can be balanced at the 82% point corresponding to the SOC of the battery with the highest SOC (BAT1).

[0115] Meanwhile, in the second control, the batteries with the highest SOC are BAT1 and BAT3 (each with an SOC of 82%), and since the difference in SOC (2%) between the SOC of the batteries with the highest SOC (82%) and the SOC of the battery with the lowest SOC (80%) (BAT2) is less than or equal to a predetermined threshold value (10%), power is supplied from the generator to the battery with the lowest SOC (BAT2), and only the charging control of the battery (BAT2) is performed, and the SOC of the three batteries can be balanced at the 82% point where the SOC of all batteries (BAT1, BAT2, BAT3) becomes the same.

[0116] FIGS. 9(a) and (b) are experimental examples of a battery management method for an electric vehicle according to the second embodiment of the present invention, in an embodiment in which the battery management system of an electric vehicle according to the present invention has three batteries. This experimental example may be a case in which three batteries (BAT1, BAT2, BAT3) are controlled in a system corresponding to, for example, FIG. 5(a).

[0117] In the experimental example of FIG. 9 (a), the difference (12%) between the SOC (84%) of the battery with the highest SOC (BAT1) and the SOC (72%) of the battery with the lowest SOC (BAT3) among the three batteries exceeds a predetermined threshold value (10%).

[0118] In this case, since the difference between the battery with the highest SOC (BAT1) and the battery with the lowest SOC (BAT3) among the three batteries exceeds a predetermined threshold, in the case of the battery with the lowest SOC (BAT3), power can be supplied from the generator (ePedal) to the battery (BAT3) to charge it. Meanwhile, in the case of the battery with the highest SOC (BAT1), power can be supplied from the battery (BAT1) to the generator (ePedal) to discharge it.

[0119] Here, according to the second embodiment of the present invention, charging and discharging are performed until the difference in SOC of the two batteries becomes below a predetermined threshold value, so the first control can be terminated when the difference in SOC reaches a predetermined threshold value. That is, the charging and discharging control can be terminated when the SOC of the battery with the highest SOC (BAT1) reaches 83% and the SOC of the battery with the lowest SOC (BAT3) reaches 73%.

[0120] Meanwhile, in the second control, since the difference (10%) between the SOC of the battery with the highest SOC (BAT1) (83%) and the SOC of the battery with the lowest SOC (BAT3) (73%) is below a predetermined threshold, power is supplied from the generator (ePedal) to the battery with the lowest SOC (BAT3), and only the charging of the battery (BAT3) can be performed. Through this charging control, the SOCs of the two batteries (BAT1, BAT3) can be balanced at the 83% point where their SOCs become equal.

[0121] Meanwhile, in the case of three batteries, since the battery management method according to the embodiment of the present invention is performed until the SOC of the three batteries becomes the same, even if the second control is terminated, the third control is performed unless the SOC of the two batteries (BAT1, BAT3) and the other battery (BAT2) becomes the same.

[0122] In the third control, since the difference (3%) between the SOC (83%) of the battery with the highest SOC (BAT1, BAT3) and the SOC (80%) of the battery with the lowest SOC (BAT2) is below a predetermined threshold, power is supplied from the generator (ePedal) to the battery with the lowest SOC (BAT2), and charging control of the battery (BAT2) is performed, and the SOC balance is achieved at the 83% point where the SOCs of all batteries (BAT1, BAT2, BAT3) become equal.

[0123] That is, compared to the experimental example according to the first embodiment of the embodiment with three batteries (Fig. 8 (a)), by performing balancing control one additional time, the effect of balancing the SOC at a higher level (80% -> 83%) can be achieved.

[0124] Experimental example of FIG. 9(b) shows a case where the difference (8%) between the SOC (82%) of the battery with the highest SOC (BAT1) and the SOC (74%) of the battery with the lowest SOC (BAT3) among the three batteries is less than or equal to a predetermined threshold value (10%).

[0125] In this case, in the first control, only the charge control for the battery with the lowest SOC (BAT3) is performed, and the SOCs of the two batteries (BAT1, BAT3) can be balanced at the 82% point corresponding to the SOC of the battery with the highest SOC (BAT1).

[0126] In addition, in the second control, only the charge control for the battery with the lowest SOC (BAT2) is performed, and the SOC of all batteries (BAT1, BAT2, BAT3) can be balanced at the 82% point corresponding to the SOC of the battery with the highest SOC (BAT1, BAT3). That is, the same result as the experimental example of the first embodiment (Fig. 8 (b)) is obtained.

[0127] As seen through the experimental examples above, according to the experimental example of the battery management method according to the first embodiment of the present invention (Figs. 6 and 8), when the difference in SOC exceeds a threshold value, the SOC of all batteries can be balanced with only one control when there are two batteries, and with only two controls when there are three batteries, thereby enabling faster balancing of the SOC of the batteries.

[0128] Meanwhile, according to the experimental example of the battery management method according to the second embodiment of the present invention (Figs. 7 and 9), when the difference in SOC exceeds a threshold value, the number of control cycles may increase compared to the case according to the first embodiment (in the experimental example, 2 control cycles when there are 2 batteries, and 3 control cycles when there are 3 batteries), but a more advantageous effect may be achieved in that the SOC can be balanced at a higher level.

[0129] As described above, according to an embodiment of the present invention, a battery management method and system can be provided for an electric vehicle comprising a plurality of batteries, which can rapidly and effectively balance the SOC of a plurality of batteries using a bidirectional converter.

[0130] In addition, according to an embodiment of the present invention, since the SOC of a plurality of batteries can be effectively balanced to drive an electric vehicle, it is possible to prevent the reduction of maximum torque and output during driving due to an imbalance of SOC, thereby enabling the electric vehicle to be driven at maximum output for a long time, thus exhibiting a significant effect.

[0131] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical concept or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0132] The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and the concept of equivalents thereof should be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0133] 100, 200, 300, 400: Battery Management System 110, 210, 310, 410: Generator (ePedal) 121, 122, 221, 222, 321, 322, 323, 421, 422, 423, 424: Battery 131, 132, 231, 232, 233, 331, 332, 333, 431, 432, 433, 434: Motor 141, 142, 241, 242, 341, 342, 343, 441, 442, 443, 444: Converter 150, 250, 350, 450: Control unit 160, 260, 360, 460: Interface

Claims

Claim 1 A battery management method for an electric vehicle, comprising: receiving State of Charge (SOC) information of a plurality of batteries mounted on the electric vehicle; and determining whether the difference between the SOC of a first battery with the highest SOC and a second battery with the lowest SOC among the plurality of batteries exceeds a predetermined threshold value. The method includes the step of controlling the power flow of at least one converter among a plurality of converters connected to the plurality of batteries to control the charging or discharging of at least one of the plurality of batteries, wherein the plurality of converters are bidirectional converters, and the plurality of converters include a first bidirectional converter connected to the first battery and a second bidirectional converter connected to the second battery, wherein when the difference between the SOC of the first battery and the SOC of the second battery exceeds the predetermined threshold value, the step of controlling the charging or discharging of at least one of the plurality of batteries comprises controlling the power flow of the first bidirectional converter to supply power from the first battery to a generator to discharge the first battery, and controlling the power flow of the second bidirectional converter to supply power from the generator to the second battery to charge the second battery, and when the difference between the SOC of the first battery and the SOC of the second battery does not exceed the predetermined threshold value, the step of controlling the charging or discharging of at least one of the plurality of batteries comprises the SOC of the first battery and the second battery A battery management method for an electric vehicle characterized by controlling only the power flow of the second bidirectional converter until the SOC becomes equal, thereby supplying power from the generator to the second battery to charge the second battery. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 A battery management method for an electric vehicle according to claim 1, wherein the step of controlling the charging or discharging of at least one of the plurality of batteries comprises controlling the power flow of the first bidirectional converter to supply power from the first battery to a generator to discharge the first battery until the SOC of the first battery and the SOC of the second battery become equal, and controlling the power flow of the second bidirectional converter to supply power from the generator to the second battery to charge the second battery. Claim 6 A battery management method for an electric vehicle according to claim 1, wherein the step of controlling the charging or discharging of at least one of the plurality of batteries comprises controlling the power flow of the first bidirectional converter to supply power from the first battery to a generator to discharge the first battery until the difference between the SOC of the first battery and the SOC of the second battery becomes less than or equal to the predetermined threshold value, and controlling the power flow of the second bidirectional converter to supply power from the generator to the second battery to charge the second battery. Claim 7 A battery management method for an electric vehicle according to any one of claims 1, 5 to 6, further comprising, after the step of controlling the charging or discharging of at least one of the plurality of batteries, a step of determining whether the SOC of the plurality of batteries is the same, and wherein the charging or discharging control of at least one of the plurality of batteries is performed until the SOC of the plurality of batteries becomes the same. Claim 8 A battery management method for an electric vehicle according to claim 7, characterized by further including a step of determining whether the system is normal after a step of determining whether the SOCs of the plurality of batteries are all the same. Claim 9 A battery management method for an electric mobility means according to claim 8, wherein the step of determining whether the system is normal is characterized by determining that the system is abnormal when the current generated by the generator is an overcurrent, when the voltage of at least one of the plurality of batteries is outside the range of the system's usable voltage, or when the component of the system is outside the range of the system's operable temperature. Claim 10 A battery management method for an electric mobility means according to claim 8, characterized by giving a warning to the driver that the system is abnormal when the system is determined to be abnormal. Claim 11 A battery management system for an electric vehicle comprises: a generator that generates voltage by driving a pedal; a plurality of batteries mounted on the electric vehicle; a plurality of motors mounted on at least one of the front wheel and rear wheel of the electric vehicle to provide rotational force to the wheel; and a plurality of converters for converting the voltage of the plurality of batteries. The system includes a control unit for controlling the system, wherein the control unit receives State of Charge (SOC) information of the plurality of batteries, determines whether the difference between the SOC of the first battery with the highest SOC and the second battery with the lowest SOC among the plurality of batteries exceeds a predetermined threshold value, and controls the power flow of at least one converter among the plurality of converters to control the charging or discharging of at least one battery among the plurality of batteries, wherein the plurality of converters are bidirectional converters, and the plurality of converters include a first bidirectional converter connected to the first battery and a second bidirectional converter connected to the second battery, wherein when the difference between the SOC of the first battery and the SOC of the second battery exceeds the predetermined threshold value, the control unit controls the power flow of the first bidirectional converter to supply power from the first battery to the generator to discharge the first battery, and controls the power flow of the second bidirectional converter to supply power from the generator to the second battery to charge the second battery, and wherein the control unit... A battery management system for an electric vehicle, characterized by controlling only the power flow of the second bidirectional converter to supply power from the generator to the second battery and charge the second battery until the SOC of the first battery and the SOC of the second battery become the same when the difference between the SOC of the battery and the SOC of the second battery does not exceed the predetermined threshold value. Claim 12 delete Claim 13 delete Claim 14 delete Claim 15 A battery management system for an electric vehicle according to claim 11, wherein the control unit controls the power flow of the first bidirectional converter to supply power from the first battery to the generator to discharge the first battery until the SOC of the first battery and the SOC of the second battery become equal, and controls the power flow of the second bidirectional converter to supply power from the generator to the second battery to charge the second battery. Claim 16 A battery management system for an electric vehicle according to claim 11, wherein the control unit controls the power flow of the first bidirectional converter to supply power from the first battery to a generator to discharge the first battery until the difference between the SOC of the first battery and the SOC of the second battery becomes less than or equal to the predetermined threshold value, and controls the power flow of the second bidirectional converter to supply power from the generator to the second battery to charge the second battery. Claim 17 A battery management system for an electric vehicle according to any one of claims 11, 15 to 16, wherein the control unit performs charging or discharging control of at least one of the plurality of batteries until the SOC of the plurality of batteries all become the same. Claim 18 A battery management system for an electric mobility means according to claim 17, wherein when the SOC of the plurality of batteries all become the same, the control unit determines whether the system is normal. Claim 19 A battery management system for an electric mobility means according to claim 18, wherein the control unit determines that the system is abnormal when the current generated by the generator is an overcurrent, when the voltage of at least one of the plurality of batteries exceeds the range of the system's usable voltage, or when the component of the system exceeds the operating temperature range. Claim 20 A battery management system for an electric vehicle according to claim 18, further comprising an interface including a display, wherein if the system is determined to be abnormal, the control unit displays a warning that the system is abnormal on the display of the interface.

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