Battery Management Unit

Abstract

To provide a battery management device that enables correction control of an SOC of a battery in an electric vehicle to be properly executed.SOLUTION: A battery management device 10, which manages a battery in an electric vehicle, comprises: an information obtaining part 12 that obtains idle-determination information which is information for determining whether the electric vehicle is in an idle state or not; a determining part 13 that when sensing that the vehicle is in a long-time idle state which is a state where the idle state continues for more than a predetermined time, determines whether correction control by which an error of an SOC of the battery is corrected should be executed, by controlling the SOC of the battery in a predetermined state by power generation by a power generator; and a correction control part 14 that when the determining part 13 determines that the correction control should be executed, executes the correction control of the SOC of the battery.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a battery management device that manages a battery of an electric vehicle. [Background technology]

[0002] There is an electric vehicle equipped with a generator, a battery, and a motor operated by the output power of the generator and / or the battery. For example, a current integration method is used as a method for managing the SOC (State of Charge) of the battery. However, in the current integration method, an error accumulates in the estimated value of the SOC due to an error in measuring the current during charging and discharging. In order to correct this error, a method is known in which the SOC is corrected by referring to the voltage value of the battery. In this method, the charge and discharge of the battery are controlled so that the SOC value falls within a range in which the change in the voltage value relative to the change in the SOC is large, and the SOC value corresponding to the voltage value is acquired, thereby correcting the error in the SOC. For example, in a lithium-ion battery using lithium iron phosphate, the change in the voltage value relative to the change in the SOC is extremely small in states other than near 0% and near 100%, so that control is performed for error correction so that the SOC is near 0% or near 100%. For example, Patent Document 1 describes charging the battery until it is fully charged, and correcting the error in the estimated value of the SOC. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 181489 Summary of the Invention [Problem to be solved by the invention]

[0004] Correction control, which corrects the SOC value by fully charging the battery so that the SOC approaches 100%, may be controlled to be performed, for example, when the operation of an electric vehicle is terminated. When such control conditions are applied, the system of the electric vehicle may continue to operate against the driver's intention due to the execution of SOC correction control. In addition, during the execution of SOC correction control, noise may be generated due to the power generation operation of the generator, and if the generator is configured as a fuel cell, water may be discharged during power generation. However, when the operation of the electric vehicle is terminated in a place where noise generation and water discharge are not permitted, there is an inconvenience that the SOC correction control may be performed against the driver's intention.

[0005] Therefore, an object of the present invention is to provide a battery management device that enables appropriate correction control of the SOC of a battery in an electric vehicle. [Means for solving the problem]

[0006] The battery management device of the present invention is a battery management device that manages a battery in an electric vehicle that has a battery, a generator, and a motor, and includes an information acquisition unit that acquires idle determination information that is information that can determine whether the electric vehicle is in an idle state or not, a judgment unit that, when it detects that the electric vehicle is in a long-term idle state in which the idle state continues for a predetermined time or more, determines to implement correction control to correct an error in the battery SOC by controlling the battery SOC to a predetermined state by generating power from the generator, and a correction control unit that implements correction control of the battery SOC when the judgment unit determines that correction control should be implemented.

[0007] The idle state of an electric vehicle is suitable for implementing SOC correction control because the system is in operation and SOC correction control can be implemented, and because the electric vehicle is not in operation and is in a low-load state. This battery management device implements SOC correction control when it detects that the idle state has continued for a predetermined period of time or longer, making it possible to appropriately implement SOC correction control of the electric vehicle's battery.

[0008] In addition, in the battery management device, the correction control unit may perform correction control by having the generator generate power at a high-efficiency operating point, which is a pre-set operating state where the power generation efficiency of the generator is equal to or greater than a predetermined value.

[0009] According to this battery management device, correction control is performed by causing the generator to generate power at a highly efficient operating point, thereby improving fuel efficiency related to the correction control.

[0010] In addition, in the battery management device, the correction control unit may perform correction control by causing the generator to generate power so that the battery is charged with permitted charging power, which is the power during charging that is permitted according to the SOC value.

[0011] According to this battery management device, when the correction control is performed, the generator is controlled so that the battery is charged with the permitted charging power, so that the battery is charged in an optimal state.

[0012] In addition, in the battery management device, the information acquisition unit acquires, as idle determination information, operation information indicating an operation state by the driver of at least one of the parking brake, transmission, brake pedal, and accelerator pedal of the electric vehicle, and a drive range indication switch for indicating the drive state of the electric vehicle, and the judgment unit may determine that the electric vehicle is in an idle state when the operation information indicates at least one of: the parking brake is applied, the transmission is not in a state for driving the electric vehicle, the brake pedal is not operated, the accelerator pedal is not operated, and the drive range indication switch has not instructed the electric vehicle to be in a drive state.

[0013] According to this battery management device, various pieces of operation information are used as idle determination information, so that it is possible to appropriately determine whether or not the vehicle is in an idle state.

[0014] In addition, in the battery management device, the information acquisition unit acquires schedule information indicating at least one of the location and time when the electric vehicle is scheduled to be in an idle state, and at least one of the current location and current time of the electric vehicle as idle determination information, and the judgment unit may determine that the electric vehicle is in an idle state when at least one of the current location and current time corresponds to at least one of the location and time when the electric vehicle is scheduled to be in an idle state indicated in the schedule information.

[0015] According to this battery management device, when the current location and / or the current time correspond to a location and / or a time when the electric vehicle is likely to be in an idle state based on the schedule information, it is determined that the electric vehicle is in an idle state. Therefore, it is easy to determine that the electric vehicle is in an idle state.

[0016] In addition, in the battery management device, the information acquisition unit acquires historical information indicating a history of at least one of the location and time when the electric vehicle entered an idle state, and at least one of the current location and current time of the electric vehicle, as idle determination information, and the judgment unit may determine that the electric vehicle is in an idle state when at least one of the current location and current time corresponds to at least one of the location and time when the electric vehicle entered an idle state indicated in the historical information.

[0017] According to this battery management device, when the current location and / or the current time correspond to the location and / or the time when the electric vehicle is likely to be in the idle state based on the history information, it is determined that the electric vehicle is in the idle state. Therefore, it is easy to determine that the electric vehicle is in the idle state.

[0018] In addition, in the battery management device, the correction control unit controls charging of the battery by the generator in either a charge priority mode, which is a control state in which the generator is caused to generate power at a high efficiency operating point, which is a preset operating state in which the power generation efficiency of the generator is equal to or greater than a predetermined value, with a predetermined value near the full charge of the SOC of the battery as a target value, or a normal control mode, which is a control state in which the generator charges and discharges the battery, with a predetermined value lower than the target value of the SOC in the charge priority mode as a target value of the SOC, and when the determination unit determines that correction control should be performed, performs control in the charge priority mode, and when correction control is not performed, performs control in the normal control mode, and the information acquisition unit acquires schedule information indicating at least one of a position and a time when the electric vehicle is scheduled to be in an idle state, and a history indicating at least one of a position and a time when the electric vehicle was in an idle state. When the determination unit detects that the electric vehicle is no longer in an idle state, it may obtain at least one of the next idle position and the next idle time at which the electric vehicle will next be in an idle state for a long period of time based on at least one of the schedule information and the history information, and when at least one of the difference between the current position of the electric vehicle and the next idle position and the difference between the current time and the next idle time is equal to or smaller than a predetermined value related to the position or time, it may cause the correction control unit to interrupt the correction control and maintain control in the charge priority mode, and when at least one of the difference between the current position of the electric vehicle and the next idle position and the difference between the current time and the next idle time exceeds a predetermined value related to the position or time, it may cause the correction control unit to interrupt the correction control and transition to control in the normal control mode.

[0019] According to this battery management device, the charging of the battery is controlled in either the charge priority mode or the normal control mode. When the electric vehicle is no longer in an idle state, the correction control is interrupted and the control in the charge priority mode is maintained at least in the following cases: when the time until the next time when the electric vehicle is expected to be in an idle state is less than a predetermined time, and / or when the distance to the position where the electric vehicle is expected to be in an idle state next is less than a predetermined distance. Therefore, since the SOC is maintained in a high state, the correction control can be completed in a short time when the correction control is resumed.

[0020] In addition, in the battery management device, the correction control is performed by controlling the SOC to the specified state in the range close to 100%, and the battery may be a battery in which the amount of change in the voltage value when the SOC is in the specified state is greater than the amount of change in the voltage value when the SOC is in a state lower than the specified state.

[0021] If the battery is one in which the change in voltage when the SOC is in a predetermined state is greater than the change in voltage when the SOC is lower than the predetermined state, the battery is charged so that the SOC is in a predetermined state in the vicinity of 100%, which makes it easier to obtain a correlation between the SOC and the voltage value. This makes it possible to perform accurate error correction of the SOC based on the voltage value.

[0022] In the battery management device, the battery may be a lithium-ion battery using lithium iron phosphate.

[0023] In general, in lithium-ion batteries using lithium iron phosphate, it is difficult to obtain a correlation between the SOC and the voltage value when the SOC is not near 0% or 100%. With this battery management device, when it is detected that the battery has been in an idle state for a long time, correction control is performed to bring the battery's SOC to a predetermined state near 100% by generating electricity from the generator, so that the SOC can be estimated more accurately. Effect of the Invention

[0024] According to the present invention, it is possible to provide a battery management device that enables appropriate correction control of the SOC of a battery in an electric vehicle. [Brief description of the drawings]

[0025] [Figure 1] 1 is a schematic diagram showing a configuration of an electric vehicle equipped with a battery management device according to an embodiment of the present invention; [Diagram 2] 2 is a functional block diagram showing a functional configuration of a battery management device; FIG. [Diagram 3] 4 is a flowchart showing the processing contents of a battery management method in the battery management device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding elements are designated by the same reference numerals, and duplicated description will be omitted.

[0027] FIG. 1 is a schematic diagram showing the configuration of an electric vehicle equipped with a battery management device according to an embodiment. As shown in FIG. 1, the battery management device 10 is mounted on an electric vehicle V. The electric vehicle V includes a fuel cell 1 (generator), a battery 2, and a motor 3. The electric vehicle V also includes a parking brake 5, a transmission 6, a brake pedal 7, and an accelerator pedal 8 that can be operated by a driver. The battery management device 10 may be configured to be able to wirelessly communicate with a traffic management system 20. Note that the electric vehicle V does not need to include the transmission 6, and the transmission 6 is a non-essential component of the electric vehicle V.

[0028] The fuel cell 1 is equipped with an FC stack (Fuel Cell Stack) that generates electricity. The electric vehicle V runs on the electricity generated by the fuel cell 1. The electricity generated by the fuel cell 1 is also used to charge the battery 2. The fuel cell 1 configured as an FC stack generates water during power generation, which must be drained. The fuel cell 1 also emits the operating noise of a cooling fan during power generation. The electric vehicle V may be equipped with an engine as a generator instead of a fuel cell.

[0029] The battery 2 stores the power generated by the fuel cell 1. The battery 2 can also store power generated by a regenerative brake or the like provided on the electric vehicle V, and further supplies power to the motor 3 when the power from the fuel cell 1 is insufficient. In this embodiment, the battery 2 is, for example, a lithium-ion battery using lithium iron phosphate.

[0030] For example, in the battery 2, which is a lithium-ion battery using lithium iron phosphate, the change in voltage value (OCV (Open Circuit Voltage)) relative to the change in SOC is large in the SOC range near 100% and near 0%, and the change in voltage value relative to the change in SOC is extremely small outside these ranges. Therefore, it is difficult to estimate the SOC based on the voltage value in the ranges other than the SOC range near 100% and near 0%. For this reason, the battery management unit 10 of this embodiment performs full charging so that the SOC of the battery 2 is close to 100%, as a correction control to correct the SOC error. That is, the battery management unit 10 of this embodiment acquires the voltage value when the SOC is close to 100%, and acquires the SOC corresponding to the acquired voltage value, thereby correcting the estimated SOC value.

[0031] The motor 3 is operated by the output power of at least one of the fuel cell 1 and the battery 2. The motor 3 drives wheels 4 provided on the electric vehicle V, thereby causing the electric vehicle V to run.

[0032] The battery management unit 10 may be configured to be capable of acquiring operation information indicating the operation states of the parking brake 5, the transmission 6, the brake pedal 7, and the accelerator pedal 8 by the driver.

[0033] The battery management device 10 can acquire schedule information from the operation management system 20. The operation management system 20 manages and stores schedule information that is information indicating the planned operation of the electric vehicle V. The schedule information includes the operation route (including position information and time information). The schedule information may also include information on the position and time when the electric vehicle V will be in a so-called loading and unloading waiting state, and information on the position and time when the driver will take a break.

[0034] The idle state of the electric vehicle V is a state in which the system is in operation and therefore SOC correction control can be implemented, and the electric vehicle is not in operation (not running). When the electric vehicle V is in a so-called loading and unloading waiting state and the driver is taking a break, the electric vehicle V is highly likely to be in an idle state. Therefore, the traffic management system 20 provides information on the location and time when the electric vehicle V is scheduled to be in an idle state to the battery management device 10 as schedule information. Note that the information on the location and time when the electric vehicle V is scheduled to be in an idle state, which is indicated in the schedule information, is not limited to information on the loading and unloading waiting state and the driver taking a break, and may be information indicating other states in which the probability of the electric vehicle V being in an idle state is high.

[0035] The battery management device 10 can acquire history information from the operation management system 20. The operation management system 20 manages and stores history information that is information indicating the operation history of the electric vehicle V. The history information is not limited to the operation history of the electric vehicle V, but may include information on the operation history of other vehicles. The history information includes at least one of information on the location and time when the electric vehicle V, etc., became idle. The history information may be generated by performing a well-known learning process on information on the operation history of the electric vehicle V, etc., and stored in the operation management system 20. At the location and time when the electric vehicle V was in an idle state in the past, there is a high probability that the electric vehicle V will become idle again in the current operation of the electric vehicle V. Therefore, the operation management system 20 provides the battery management device 10 with information on the location and time when the electric vehicle V is highly likely to become idle as history information.

[0036] 2 is a functional block diagram showing a functional configuration of the battery management device 10. The battery management device 10 manages the battery 2. In this embodiment, the battery management device 10 can manage the SOC (State Of Charge) of the battery 2. The SOC of the battery 2 managed by the battery management device 10 is used for various controls in the electric vehicle V, such as control of the motor 3.

[0037] The battery management device 10 includes an ECU (Electronic Control Unit) 100. The ECU 100 is an electronic control unit having a CPU, a ROM, a RAM, and the like. For example, the ECU 100 loads a program recorded in the ROM into the RAM and executes the program loaded into the RAM with the CPU, thereby implementing various functions. The ECU 100 may be composed of multiple electronic units.

[0038] As shown in FIG. 2, the battery management device 10 functionally includes a SOC estimation unit 11, an information acquisition unit 12, a determination unit 13, and a correction control unit .

[0039] The SOC estimation unit 11 estimates the SOC of the battery 2 based on the usage status of the battery 2. As described above, when the SOC of the battery 2 is in a state other than near 100% or near 0%, it is difficult to estimate the SOC from the voltage value based on the correlation between the voltage value and the SOC of the battery 2. For this reason, the SOC estimation unit 11 estimates the SOC of the battery 2 based on a value obtained by integrating the current values ​​during charging and discharging, for example, using a current integration method.

[0040] Here, when the SOC estimator 11 estimates the SOC by the current integration method, an error occurs between the estimated SOC and the actual SOC of the battery 2 due to a measurement error of the current value, etc. For this reason, the SOC estimator 11 corrects the estimated SOC at a predetermined timing. That is, as described in detail later, the correction controller 14 performs a correction control of fully charging the battery 2 so that the SOC of the battery 2 becomes close to 100%, and the SOC estimator 11 obtains a voltage value when the SOC is close to 100%, and obtains the SOC corresponding to the obtained voltage value, thereby correcting the estimated value of the SOC.

[0041] The information acquisition unit 12 acquires idle determination information that is information that can determine whether or not the electric vehicle V is in an idle state. The information acquisition unit 12 may acquire operation information indicating an operation state by the driver of at least one of the parking brake 5, the transmission 6, the brake pedal 7, and the accelerator pedal 8 as the idle determination information. The information acquisition unit 12 may also acquire operation information indicating an operation state of a drive range instruction switch for instructing the drive state of the electric vehicle as the idle determination information.

[0042] Furthermore, the information acquisition unit 12 may acquire schedule information as the idle determination information. In this case, the information acquisition unit 12 further acquires the current position of the electric vehicle V and the current time as the idle determination information.

[0043] Furthermore, the information acquisition unit 12 may acquire history information as the idle determination information. In this case, the information acquisition unit 12 further acquires the current position of the electric vehicle V and the current time as the idle determination information.

[0044] When the judgment unit 13 detects that the idle state is a long-term idle state, which is a state in which the idle state continues for more than a predetermined time, it determines to implement correction control to correct an error in the SOC of the battery 2 by controlling the SOC of the battery 2 to a predetermined state by generating power from the fuel cell 1.

[0045] The correction control unit 14 performs correction control of the SOC of the battery 2 when the determination unit 13 determines that correction control should be performed. Specifically, the correction control unit 14 performs correction control by sending a power generation command at a predetermined operating point to the fuel cell 1 and operating the fuel cell 1. More specifically, the correction control unit 14 sends a power generation command including a specified power value to the fuel cell 1. Furthermore, when a generator for charging the battery 2 is configured by an engine instead of the fuel cell 1, the correction control unit 14 sends a power generation command including a rotation speed and a torque value to the engine (generator).

[0046] During correction control, the correction control unit 14 sets the target SOC value to a value close to full charge and controls the power generation of the fuel cell 1. On the other hand, when correction control is not performed, the correction control unit 14 sets the target SOC value to a preset value, not full charge, and controls the power generation of the fuel cell 1. This preset value is called, for example, the SOC center.

[0047] The correction control unit 14 may perform the correction control by making the generator generate power at a high-efficiency operating point, which is a preset operating state where the power generation efficiency of the generator is equal to or greater than a predetermined value. In this embodiment, the correction control unit 14 makes the fuel cell 1 generate power at a high-efficiency operating point, which is a preset operating state where the power generation efficiency of the fuel cell 1 is equal to or greater than a predetermined value. Generally, the lighter the load of the fuel cell 1, the less loss there is and the more efficiently the fuel cell 1 can generate power. By making the fuel cell 1 generate power at the high-efficiency operating point in this way and performing the correction control, the fuel efficiency related to the correction control is improved.

[0048] Furthermore, the correction control unit 14 may execute the correction control by making the generator generate power so that the battery 2 is charged with the permitted charging power, which is the power during charging permitted according to the value of the SOC. In general, the range of permitted charging power for the battery 2 becomes narrower as the value of the SOC increases. Specifically, the correction control unit 14 previously associates and stores the range of permitted charging power with the predicted value of the SOC, and controls the generator to generate power according to the value of the SOC acquired by the SOC estimation unit 11. In this way, when the correction control is executed, the generator is controlled so that the battery 2 is charged with the permitted charging power, so that the battery 2 is charged in an optimal state.

[0049] The correction control unit 14 may control the charging of the battery 2 by the generator in either the charge priority mode or the normal control mode. In this embodiment, the correction control unit 14 controls the charging of the battery 2 by the fuel cell 1 in either the charge priority mode or the normal control mode.

[0050] The charge priority mode is a control state in which the generator generates power at a high efficiency operating point, which is a preset operating state in which the power generation efficiency of the generator is equal to or greater than a predetermined value, with a target value of a predetermined value near the full charge of the SOC of the battery 2. The normal control mode is a control state in which the generator charges and discharges the battery, with a target SOC value set to a predetermined value (e.g., the SOC center) lower than the target SOC value in the charge priority mode.

[0051] The correction control unit 14 may perform control in the charge priority mode when the determination unit 13 determines that the correction control is to be performed, and may perform control in the normal control mode when the correction control is not performed.

[0052] Fig. 3 is a flowchart showing the processing of the battery management method in the battery management device 10. The processing shown in the flowchart in Fig. 3 is started, for example, when a predetermined SOC correction request event occurs. The SOC correction request event may be, for example, the passage of a predetermined time since the previous SOC correction control was performed, the cumulative driving time of the electric vehicle V reaching a predetermined time, an explicit input by the driver, or the like, but is not limited to these examples.

[0053] In step S1, the information acquisition unit 12 acquires predetermined idle determination information for detecting an idle state. The idle determination information may be operation information indicating an operation state by the driver of at least one of the parking brake 5, the transmission 6, the brake pedal 7, the accelerator pedal 8, and the drive range indication switch. The idle determination information may also include either or both of schedule information and history information. The idle determination information may also include the current position of the electric vehicle V and the current time.

[0054] In step S2, the determination unit 13 determines whether or not the electric vehicle V is in a long-time idle state. The long-time idle state is a state in which the idle state continues for a predetermined time or longer.

[0055] The judgment unit 13 may determine that the electric vehicle V is in an idle state when the operation information indicates at least one of the following: the parking brake 5 is applied, the transmission 6 is not in a state to drive the electric vehicle V (for example, in P range or N range), the brake pedal 7 is not operated, and the accelerator pedal 8 is not operated.

[0056] The determination unit 13 may acquire, as the operation information, driving range information indicating the driving state of the wheels 4 by the motor 3. The driving range information indicates, for example, any one of the driving states of P range (parking), N range (neutral), R range (reverse drive), and D range (forward drive). The driving state is indicated, for example, by the driver's operation of a driving range indication switch (not shown), which is a switch for switching and indicating the driving state. The determination unit 13 may determine that the electric vehicle V is in an idle state when the driving range information is the P range or the N range (when the electric vehicle V is not in a driven state). By referring to the driving range information, the determination unit 13 can determine the driving state of the electric vehicle V even when the electric vehicle V does not have a transmission 6.

[0057] In addition, when schedule information is used as idle determination information, the judgment unit 13 determines that the device is in an idle state when at least one of the following cases is true: the current location corresponds to a location where the device is scheduled to be in an idle state as indicated in the schedule information, and the current time corresponds to a time where the device is scheduled to be in an idle state as indicated in the schedule information.

[0058] In addition, when the history information is used as idle determination information, the judgment unit 13 determines that the vehicle is in an idle state when at least one of the following cases is true: the current location corresponds to the location at which the vehicle entered the idle state indicated in the history information, and the current time corresponds to the time at which the vehicle entered the idle state indicated in the history information.

[0059] The judgment unit 13 may determine that the electric vehicle V is in an idle state using any one of the operation information, the schedule information, and the history information, or may determine that the electric vehicle V is in an idle state using multiple pieces of information among the operation information, the schedule information, and the history information.

[0060] If it is determined that the electric vehicle V has been in an idle state for a long time, the process proceeds to step S3. On the other hand, if it is not determined that the electric vehicle V has been in an idle state for a long time, the acquisition process of step S1 and the determination process of step S2 are repeated.

[0061] In step S3, the determination unit 13 sets a long-time idle flag, which is a flag for retaining information that the electric vehicle V has been in an idle state for a long time, to 1. Note that in the battery management unit 10, the means for retaining information that the electric vehicle V has been in an idle state for a long time is not limited to a flag.

[0062] In step S4, the judgment unit 13 judges to perform SOC correction control. The correction control unit 14 performs SOC correction control by controlling charging so that the SOC of the battery 2 becomes a value close to full charge. At this time, the correction control unit 14 controls the fuel cell 1 (generator) so that power is generated at a predetermined high-efficiency operating point. The correction control unit 14 also controls the fuel cell 1 so that the battery 2 is charged with the permitted charging power according to the value of the SOC.

[0063] The correction control unit 14 may also perform the SOC correction control in the charge priority mode out of the charge priority mode and the normal control mode. The charge priority mode is a control state in which the generator is caused to generate power at a high efficiency operating point, which is a preset operating state in which the power generation efficiency of the generator is equal to or greater than a predetermined value, with a predetermined value near the full charge of the SOC of the battery 2 as a target value. Note that, when the processing procedure reaches step S4 after the processing of step S9 is performed, the control in the charge priority mode is performed, so the correction control unit 14 maintains the control state in the charge priority mode.

[0064] In step S5, the determination unit 13 determines whether the SOC correction control has ended. Specifically, the determination unit 13 may determine that the SOC correction control has ended, for example, when it is detected that the voltage value of the battery 2 has reached a predetermined value or more. When it is determined that the SOC correction control has ended, the process shown in the flowchart of Fig. 3 ends. On the other hand, when it is not determined that the SOC correction control has ended, the process proceeds to step S6.

[0065] In step S6, the determination unit 13 determines whether the long-time idle flag is 1. The long-time idle flag is set to 0 if the condition used as the basis for determining in step S2 that the electric vehicle V is in a long-time idle state is not satisfied. Therefore, if the long-time idle flag is 1, the electric vehicle V continues to be in an idle state, and if the long-time idle flag is 0, the electric vehicle V is not in an idle state. If it is determined that the long-time idle flag is 1, the process returns to step S5, and the SOC correction control continues. On the other hand, if it is not determined that the long-time idle flag is 1, the process proceeds to step S7.

[0066] In step S7, the determination unit 13 predicts at least one of an interval until the next idle position, which is a position where the electric vehicle will be in an idle state for the next longest time, and an interval until the next idle time, which is a time where the electric vehicle will be in an idle state for the next longest time. Specifically, in order to predict the interval, the information acquisition unit 12 acquires at least one of schedule information and history information. The determination unit 13 acquires at least one of the next idle position and the next idle time based on the schedule information and the history information. The determination unit 13 calculates at least one of the difference between the current position of the electric vehicle and the next idle position, and the difference between the current time and the next idle time, as the interval until the electric vehicle will be in an idle state for the next longest time.

[0067] In step S8, the determination unit 13 determines whether the interval until the next long-time idle state is equal to or less than a predetermined value related to the position or time. If it is determined that the interval is equal to or less than the predetermined value related to the position or time, the process proceeds to step S9. On the other hand, if it is not determined that the interval is equal to or less than the predetermined value related to the position or time, the process proceeds to step S10.

[0068] In step S9, the determination unit 13 causes the correction control unit 14 to suspend the SOC correction control and maintain the control in the charge priority mode. The correction control unit 14 suspends the SOC correction control but maintains the control in the charge priority mode, which was the control state when the correction control was performed.

[0069] By maintaining the charge priority mode in this way, the SOC of the battery 2 is maintained at a high state, so that when the correction control is resumed, it is possible to complete the correction control in a short time. Furthermore, by maintaining the SOC of the battery 2 at a high state, loss due to charging and discharging of the battery 2 is suppressed, so that fuel economy is improved. Furthermore, by maintaining the SOC of the battery 2 at a high state, the degree of decrease in the amount of regenerative energy is reduced, and deterioration of fuel economy due to a decrease in the regenerative braking force of the motor 3 and a large amount of regenerative energy not being taken up is prevented.

[0070] In step S10, the judgment unit 13 causes the correction control unit 14 to stop the correction control and to switch to control in the normal control mode. The correction control unit 14 stops the SOC correction control. The correction control unit 14 also changes the control state to the normal control mode. After the processes of steps S9 and S10, the process returns to step S1.

[0071] As described above, in the battery management device 10 of this embodiment, when it is detected that an idle state suitable for implementing SOC correction control is a long-term idle state that continues for a predetermined time or more, SOC correction control is implemented, so that it is possible to appropriately implement SOC correction control of the battery 2 of the electric vehicle V.

[0072] The present invention has been described in detail above based on the embodiments. However, the present invention is not limited to the above embodiments. Various modifications of the present invention are possible without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0073] 1... fuel cell, 2... battery, 3... motor, 4... wheels, 5... parking brake, 6... transmission, 7... brake pedal, 8... accelerator pedal, 10... battery management device, 11... SOC estimation unit, 12... information acquisition unit, 13... judgment unit, 14... correction control unit, 20... driving management system, V... electric vehicle.

Claims

1. A battery management device for managing a battery in an electric vehicle including a battery, a generator, and a motor, comprising: an information acquisition unit that acquires idle determination information that is information that can determine whether the electric vehicle is in an idle state; a determination unit that, when detecting a long-time idle state in which the idle state continues for a predetermined time or more, determines to execute a correction control for correcting an error in an SOC of the battery by controlling an SOC of the battery to a predetermined state by power generation of the generator; a correction control unit that performs the correction control of the SOC of the battery when the determination unit determines that the correction control is to be performed; A battery management device comprising:

2. The correction control unit performs the correction control by making the generator generate power at a high-efficiency operating point, which is a preset operating state where the power generation efficiency of the generator is equal to or higher than a predetermined value. The battery management device according to claim 1 .

3. The correction control unit performs the correction control by causing the generator to generate power so that the battery is charged with an allowed charging power, which is power during charging permitted according to the value of the SOC. The battery management device according to claim 1 or 2.

4. the information acquisition unit acquires, as the idle determination information, operation information indicating an operation state by a driver of at least one of a parking brake, a transmission, a brake pedal, and an accelerator pedal of the electric vehicle, and a drive range indication switch for indicating a drive state of the electric vehicle; the determination unit determines that the electric vehicle is in the idle state when the operation information indicates at least one of the following: the parking brake is applied, the transmission is not in a state for driving the electric vehicle, the brake pedal is not operated, the accelerator pedal is not operated, and the drive range instruction switch has not instructed the electric vehicle to be in a driven state. The battery management device according to any one of claims 1 to 3.

5. the information acquisition unit acquires, as the idle determination information, schedule information indicating at least one of a location and a time when the electric vehicle is scheduled to be in the idle state, and at least one of a current location and a current time of the electric vehicle; the determination unit determines that the vehicle is in the idle state when at least one of the current location and the current time corresponds to at least one of a location and a time at which the vehicle is scheduled to be in the idle state, which are indicated in the schedule information; The battery management device according to any one of claims 1 to 4.

6. the information acquisition unit acquires, as the idle determination information, history information indicating a history of at least one of a position and a time when the electric vehicle entered the idle state, and at least one of a current position and a current time of the electric vehicle; the determination unit determines that the vehicle is in the idle state when at least one of the current location and the current time corresponds to at least one of the location and the time at which the vehicle became in the idle state, which are indicated in the history information; The battery management device according to any one of claims 1 to 5.

7. The correction control unit is controlling charging of the battery by the generator in either a charge priority mode, which is a control state in which the generator is caused to generate power at a high efficiency operating point, which is a pre-set operating state in which the power generation efficiency of the generator is equal to or greater than a predetermined value, with a predetermined value near the full charge value of the SOC of the battery as a target value, or a normal control mode, which is a control state in which the generator charges and discharges the battery, with a predetermined value lower than the target value of the SOC in the charge priority mode as the target value of the SOC; When the determination unit determines that the correction control is to be performed, a control in the charge priority mode is performed, and when the correction control is not performed, a control in the normal control mode is performed; the information acquisition unit acquires at least one of schedule information indicating at least one of a location and a time when the electric vehicle is scheduled to be in the idle state, and history information indicating a history of at least one of a location and a time when the electric vehicle has been in the idle state, The determination unit is when it is detected that the electric vehicle is no longer in the idle state, acquiring at least one of a next idle position and a next idle time at which the electric vehicle will next enter the long-time idle state based on at least one of the schedule information and the history information; when at least one of a difference between a current position of the electric vehicle and the next idle position and a difference between a current time and the next idle time is equal to or less than a predetermined value related to position or time, causing the correction control unit to interrupt the correction control and maintain control in the charge priority mode; when at least one of a difference between a current position of the electric vehicle and the next idling position and a difference between a current time and the next idling time exceeds the predetermined value related to the position or the time, causing the correction control unit to stop the correction control and to transition to control in the normal control mode; The battery management device according to any one of claims 1 to 6.

8. The correction control is performed by controlling the SOC to the predetermined state in a range close to 100%. The battery is a battery in which a change amount of a voltage value when the SOC is in the predetermined state is larger than a change amount of a voltage value when the SOC is in a state lower than the predetermined state. The battery management device according to any one of claims 1 to 7.

9. The battery is a lithium-ion battery using lithium iron phosphate. The battery management device according to claim 8 .

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