Vehicle driving control system, vehicle, and vehicle driving control method

Abstract

The present invention relates to a vehicle driving control system, a vehicle, and a vehicle driving control method. A driving control system for a vehicle, and the vehicle includes a battery pack. The battery pack includes a battery, a current sensor configured to detect a current for charging and discharging the battery, and a first control device for monitoring the state of the battery. The driving control system includes: a rotating electric machine configured to consume electric power to generate a driving force and configured to generate electric power; a power conversion device electrically connected between the battery and the rotating electric machine; and a second control device.

Description

Technical Field

[0001] The present disclosure relates to a travel control system for a vehicle, a vehicle, and a travel control method for a vehicle, and more particularly, to a travel control for a vehicle equipped with a battery. Background Art

[0002] In recent years, vehicles equipped with batteries such as hybrid vehicles and electric vehicles have been widely used. Hereinafter, these vehicles are also referred to as "electric vehicles". A typical electric vehicle is provided with a plurality of electronic control units (ECUs) separated by function. For example, the hybrid vehicle disclosed in Japanese Patent Publication No. 2019-156007 (JP 2019-156007A) includes an engine ECU, a motor ECU, a battery ECU, and a hybrid vehicle (HV) ECU. The HV ECU is connected to the engine ECU, the motor ECU, and the battery ECU via a communication port, and sends various control signals and data to the engine ECU, the motor ECU, and the battery ECU, and receives various control signals and data from them. Summary of the invention

[0003] In the following, a configuration is assumed in which a battery pack and a driving control system are installed on an electric vehicle. The battery pack includes a battery, a current sensor that detects the current for charging and discharging the battery, and an ECU (hereinafter referred to as the first ECU) that monitors the state of the battery. The driving control system includes: a rotating electric machine (motor generator) that can consume electric power to generate a driving force and generate electric power; a power conversion device (inverter, etc.) that is electrically connected between the battery and the rotating electric machine; and an ECU that controls the power conversion device (hereinafter referred to as the second ECU). The first ECU and the second ECU are configured to be able to communicate with each other.

[0004] The automotive industry is considered to have a vertically integrated industrial structure. However, in the future, as electric vehicles are further promoted worldwide, horizontal division of labor regarding electric vehicles is likely to progress.

[0005] It is conceivable that a business entity that handles a battery pack (hereinafter referred to as Company A) and a business entity that handles a driving control system (hereinafter referred to as Company B) operate separately. For example, Company B sells a driving control system to Company A. Company A develops an electric vehicle by combining the driving control system purchased from Company B with a battery pack designed by Company A. In this case in particular, compatibility between the battery pack and the driving control system may become a problem.

[0006] More specifically, Company A has accumulated experience in the protection and use of "current-based" batteries, which is a common practice in the field of secondary battery research and development. On the other hand, Company B is familiar with "power-based" control of battery charge / discharge, which is applicable to control power conversion devices such as inverters. In this case, what parameters are used for communication between the first ECU in the battery pack and the second ECU in the driving control system may become a problem.

[0007] Specifically, it is conceivable that the current (detection value of the current sensor) that actually charges and discharges the battery and the "permissible current" that is the current that allows the battery to be charged and discharged from the battery from the perspective of protecting the battery are output from the first ECU to the second ECU. It is desirable that the second ECU controls the power conversion device based on the permissible current received from the first ECU rather than based on the power-based parameters (power limit values ​​Win and Wout to be described later).

[0008] The present disclosure can ensure compatibility between two ECUs.

[0009] A driving control system according to an aspect of the present disclosure is a driving control system for a vehicle including a battery pack. The battery pack includes a battery, a current sensor configured to detect a current for charging and discharging the battery, and a first control device for monitoring the state of the battery. The driving control system includes a rotating motor, a power conversion device, and a second control device. The rotating motor is configured to consume power to generate a driving force, and is configured to generate power. The power conversion device is electrically connected between the battery and the rotating motor. The second control device has a power limit value indicating the power allowed to charge and discharge the battery, and is configured to perform current feedback control when the detection value of the current sensor exceeds a control threshold value, so as to correct the power limit value based on the amount by which the detection value exceeds the control threshold value, and is configured to control the power conversion device. The second control device is configured to receive the allowable current of the battery from the first control device, and perform current feedback control using the allowable current as a control threshold value. The allowable current is determined to protect the battery.

[0010] According to the above configuration, the second control device is configured to perform current feedback control when the detection value of the current sensor exceeds the control threshold value to correct the power limit value of the battery (discharge power limit value Wout to be described later) based on the amount by which the detection value exceeds the control threshold value. As the control threshold value, the allowable current output from the first control device to the second control device is used. Therefore, even when the information based on power (power limit value) is not output from the first control device to the second control device, the second control device can perform current feedback control and appropriately limit the power limit value. Therefore, the compatibility between the two control devices (the first control device and the second control device) can be ensured.

[0011] In the above aspect, the second control device may be configured to perform the current feedback control using a value obtained by subtracting a predetermined margin from the allowable current as the control threshold value.

[0012] In the above configuration, a value obtained by subtracting a margin from the allowable current is used as the control threshold. That is, the second control device is configured to start correcting the power limit value when the detection value of the current sensor reaches a value obtained by subtracting a margin from the allowable current. This suppresses the charge / discharge current of the battery so that it does not greatly exceed the allowable current. Therefore, according to the above configuration, the battery can be protected more effectively.

[0013] In the above aspect, the second control device may be configured to perform current feedback control using the smaller of an upper limit current determined to protect an electrical component electrically connected between the battery and the power conversion device and an allowable current from the first control device as the control threshold.

[0014] According to the above configuration, it is possible to protect the electric components (such as a wiring harness in an example to be described later) with the upper limit current, and to protect the battery with the allowable current.

[0015] A vehicle according to a second aspect of the present disclosure includes a travel control system, a battery, a current sensor, and a first control device.

[0016] According to the above configuration, compatibility between the two control devices can be ensured.

[0017] A third aspect of the present disclosure relates to a driving control method for a vehicle. The vehicle includes a battery pack and a driving control system. The battery pack includes a battery, a current sensor configured to detect a current for charging and discharging the battery, and a first control device for monitoring the state of the battery. The driving control system includes: a rotating motor configured to consume power to generate a driving force and configured to generate power; a power conversion device electrically connected between the battery and the rotating motor; and a second control device for controlling the power conversion device. The driving control method includes: outputting an allowable current of the battery from the first control device to the second control device, the allowable current being determined to protect the battery; and using the second control device, performing current feedback control using the allowable current as a control threshold. The current feedback control is: when the detection value of the current sensor exceeds the control threshold, control is performed to correct a power limit value based on the amount by which the detection value exceeds the control threshold, and the power limit value indicates the power allowed to charge and discharge the battery.

[0018] According to the above configuration, compatibility between the two control devices can be ensured.

[0019] According to the present disclosure, compatibility between two control devices can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like symbols represent like elements, and in which:

[0021] Figure 1 is a schematic diagram schematically showing the overall configuration of the vehicle in this embodiment;

[0022] Figure 2 is a functional block diagram of a hybrid vehicle (HV) ECU related to current feedback control in this embodiment;

[0023] Figure 3 is a flowchart showing a process performed before current feedback control in this embodiment;

[0024] Figure 4 is a functional block diagram of an HV ECU related to current feedback control in the first modification;

[0025] Figure 5 is a flowchart showing a processing procedure performed before current feedback control in the first modification;

[0026] Figure 6 An example showing time changes of the current and the allowable discharge current of the battery; and

[0027] Figure 7 is a flowchart showing a processing procedure performed before current feedback control in the second modification. DETAILED DESCRIPTION

[0028] The embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that the same or corresponding parts in the drawings are denoted by the same reference characters, and their repeated description will be omitted.

[0029] Hereinafter, a configuration in which the travel control system according to the present disclosure is mounted on a hybrid vehicle will be described as an example. However, the travel control system according to the present disclosure may be mounted on other types of electric vehicles (electric vehicles, fuel cell vehicles, etc.).

[0030] Example

[0031] Overall vehicle configuration

[0032] Figure 1 Schematic diagram schematically showing the overall configuration of the vehicle in this embodiment. Figure 1, a vehicle 9 is a hybrid vehicle, and includes a battery pack 1 and a hybrid vehicle (HV) system 2. The HV system 2 may be regarded as a "driving control system" according to the present disclosure.

[0033] The battery pack 1 includes a battery 10, a battery sensor group 20, a system main relay (SMR) 30, and a battery electronic control unit (ECU) 40. The HV system 2 includes a power control unit (PCU) 50, a first motor generator (MG) 61, a second motor generator 62, an engine 70, a power distribution device 81, a drive shaft 82, a drive wheel 83, an accelerator position sensor 91, a vehicle speed sensor 92, and an HV ECU 100.

[0034] The battery 10 includes an assembled battery composed of a plurality of battery cells. Each cell is a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. The battery 10 stores power for driving the first motor generator 61 and the second motor generator 62, and supplies power to the first motor generator 61 and the second motor generator 62 through the PCU 50. Further, when the first motor generator 61 and the second motor generator 62 generate power, the battery 10 receives the generated power through the PCU 50 and is charged.

[0035] The battery sensor group 20 includes a voltage sensor 21, a current sensor 22, and a temperature sensor 23. The voltage sensor 21 detects a voltage VB of each cell included in the battery 10. The current sensor 22 detects a current IB that charges and discharges the battery 10. The temperature sensor 23 detects a temperature TB of the battery 10. The sensor outputs the detection result to the battery ECU 40.

[0036] The SMR 30 is electrically connected to a power line that connects the battery 10 and the PCU 50. The SMR 30 switches electrical connection and disconnection between the PCU 50 and the battery 10 according to a control command from the HV ECU 100.

[0037] The battery ECU 40 includes a processor 41 such as a central processing unit (CPU), a memory 42 such as a read-only memory (ROM) and a random access memory (RAM), and an input / output port (not shown) for inputting / outputting various signals. The battery ECU 40 monitors the state of the battery 10 based on the signals received from the sensors of the battery sensor group 20 and the program and map stored in the memory 42.

[0038] The main processing performed by the battery ECU 40 includes the calculation processing of the allowable charging current Ipin and the allowable discharging current Ipd of the battery 10. From the perspective of protecting the battery 10, the allowable charging current Ipin of the battery 10 is the maximum current allowed to charge the battery 10. Likewise, from the perspective of protecting the battery 10, the allowable discharging current Ipd of the battery 10 is the maximum current allowed to be discharged from the battery 10. The battery ECU 40 outputs the calculated allowable charging current Ipin and the calculated allowable discharging current Ipd to the HV ECU 100. It is to be noted that either or both of the allowable charging current Ipin and the allowable discharging current Ipd may be regarded as the "allowable current" according to the present disclosure.

[0039] According to a control command from the HV ECU 100, the PCU 50 performs bidirectional power conversion between the battery 10 and the first motor generator 61 and the second motor generator 62 or between the first motor generator 61 and the second motor generator 62. The PCU 50 is configured to be able to individually control the states of the first motor generator 61 and the second motor generator 62. More specifically, for example, the PCU 50 includes two inverters (not shown) provided corresponding to the first motor generator 61 and the second motor generator 62 and a converter (not shown) that boosts a direct current (DC) voltage supplied to each inverter to an output voltage of the battery 10 or higher. Therefore, for example, the PCU 50 can put the second motor generator 62 into a power running state while putting the first motor generator 61 into a regenerative state (power generation state).

[0040] The PCU 50 may be regarded as a “power conversion device” according to the present disclosure. However, when the vehicle 9 is configured to be capable of external charging for charging the battery 10 with electric power supplied from the outside (for example, when the vehicle is a plug-in hybrid vehicle), the “power conversion device” according to the present disclosure may be a charger that converts electric power from outside the vehicle into charging power for the battery 10.

[0041] Each of the first motor generator 61 and the second motor generator 62 is an alternating current (AC) rotating electric machine, such as a three-phase AC synchronous motor in which a permanent magnet is embedded in a rotor. At least one of the first motor generator 61 and the second motor generator 62 may be regarded as a "rotating electric machine" according to the present disclosure.

[0042] The first motor generator 61 mainly functions as a generator driven by the engine 70 through the power split device 81. The electric power generated by the first motor generator 61 is supplied to the second motor generator 62 or the battery 10 via the PCU 50. The first motor generator 61 can also crank the engine 70.

[0043] The second motor generator 62 mainly operates as a motor and drives the drive wheel 83. The second motor generator 62 is driven by receiving at least one of the power from the battery 10 and the power generated by the first motor generator 61, and transmits the driving force of the second motor generator 62 to the drive shaft (output shaft) 72. On the other hand, when the vehicle brakes or the acceleration decreases on a descending slope, the second motor generator 62 operates as a generator to perform regenerative power generation. The power generated by the second motor generator 62 is supplied to the battery 10 via the PCU 50.

[0044] The engine 70 outputs power by converting combustion energy generated when a mixture of air and fuel is combusted into kinetic energy of a moving element such as a piston or a rotor.

[0045] For example, the power distribution device 81 is a planetary gear device. Although not shown, the power distribution device 81 includes a sun gear, a ring gear, a pinion gear, and a gear carrier. The gear carrier is connected to the engine 70. The sun gear is connected to the first motor generator 61. The ring gear is connected to the second motor generator 62 and the drive wheel 83 via the drive shaft 82. The pinion gear meshes with the sun gear and the ring gear. The gear carrier carries the pinion gear so that the pinion gear can rotate and turn.

[0046] The accelerator position sensor 91 detects the amount of depression of an accelerator pedal (not shown) by a user as an accelerator operation amount ACC and outputs the detection result to the HV ECU 100. The vehicle speed sensor 92 detects the rotation speed of the drive shaft 82 as a vehicle speed V and outputs the detection result to the HV ECU 100.

[0047] The HV ECU 100 includes a processor 101 such as a CPU, a memory 102 such as a ROM and a RAM, and an input / output port (not shown) similarly to the battery ECU 40. The HV ECU 100 performs travel control of the vehicle 9 based on data from the battery ECU 40 and a program and a map stored in the memory 102. The details of the control will be described later.

[0048] The battery ECU 40 may be regarded as a “first control device” according to the present disclosure. The HV ECU 100 may be regarded as a “second control device” according to the present disclosure. The HV ECU 100 may be further divided into a plurality of ECUs (engine ECU, MG ECU, etc.) by function, as described in JP2019-156007A.

[0049] Communication between ECUs

[0050] The automobile industry is considered to have a vertically integrated industrial structure. However, in the future, as electric vehicles are further promoted worldwide, horizontal division of labor regarding electric vehicles is likely to progress. One point of concern to the inventors of the present disclosure is that when such a transformation of the industrial structure progresses, the following problems may occur.

[0051] It is conceivable that a business entity that handles the battery pack 1 (hereinafter referred to as company A) and a business entity that handles the HV system 2 (hereinafter referred to as company B) operate separately. For example, company B sells the HV system 2 to company A. Company A develops a vehicle 9 by combining the HV system 2 purchased from company B with the battery pack 1 designed (or acquired) by company A. In this case in particular, compatibility between the battery pack 1 and the HV system 2 may become a problem.

[0052] More specifically, Company A has accumulated experience in the protection and use of the battery 10 based on current, which is a conventional means in the field of research and development of secondary batteries. On the other hand, Company B is familiar with the power-based control of the charge / discharge of the battery 10, which is applicable to the control of the PCU 50. Company B uses the charging power control upper limit value Win as the control upper limit value of the charging power of the battery 10 and the discharge power limit value Wout as the control upper limit value of the discharge power of the battery 10 to perform the charge / discharge control of the battery 10. In this case, the HV ECU 100 only needs to be able to receive the charging power control upper limit value Win and the discharge power limit value Wout of the battery 10 from the battery ECU 40. However, Company A is not familiar with the technology of outputting the charging power control upper limit value Win and the discharge power limit value Wout from the battery ECU 40. Therefore, what parameters should be used for the communication between the battery ECU 40 and the HV ECU 100 (which of the current-based communication and the power-based communication is performed) may become a problem.

[0053] In the present embodiment, it is assumed that the current-based communication is performed based on the intention of company A, where company B sells the HV system 2 to company A. Specifically, as described above, the battery ECU 40 outputs the allowable charging current Ipin and the allowable discharging current Ipd that are allowed to charge and discharge the battery 10 to the HV ECU 100 to protect the battery 10. The HVECU 100 performs feedback control on the PCU 50 based on the allowable charging current Ipin and the allowable discharging current Ipd received from the battery ECU 40. This control is called "current feedback control" and will be described in detail.

[0054] The current feedback control when charging the battery 10 and the current feedback control when discharging the battery 10 are basically the same. Therefore, in the following, the current feedback control based on the allowable discharge current Ipd when discharging the battery 10 will be representatively described. With respect to the charge / discharge direction (signs of current and power) of the battery 10, the positive direction is defined as the discharge direction, and the negative direction is defined as the charge direction.

[0055] Current Feedback Control

[0056] Figure 2 is a functional block diagram of the HV ECU 100 related to the current feedback control in this embodiment. Figure 2 The HVECU 100 includes a Wout storage unit 11 , a feedback control unit 12 , a subtraction unit 13 , a motor power calculation unit 14 , a motor torque calculation unit 15 , and a PCU control unit 16 .

[0057] The Wout storage unit 11 stores the discharge power limit value Wout. The discharge power from the battery 10 is limited not to exceed the discharge power limit value Wout. The discharge power limit value Wout may be a fixed value or may be a variable value calculated according to the state of charge (SOC) and / or temperature TB of the battery 10. The Wout storage unit 11 outputs the discharge power limit value Wout of the battery 10 to the subtraction unit 13.

[0058] The feedback control unit 12 receives the detection value of the current IB from the battery ECU 40 at a prescribed cycle (for example, several hundred milliseconds). The battery ECU 40 may perform a smoothing process (a stepwise change process) on the signal (detection value) from the current sensor 22, and output the value after the smoothing process to the feedback control unit 12. For example, the smoothing process is a process of averaging the detection value of the current sensor 22 using a predetermined time constant.

[0059] The feedback control unit 12 is configured to perform current feedback control to control the current so that the current IB is lower than the control threshold value TH when the detection value of the current IB exceeds the control threshold value TH. In addition to the detection value of the current IB, the feedback control unit 12 also receives the allowable discharge current Ipd of the battery 10 from the battery ECU 40. Then, the feedback control unit 12 substitutes the allowable discharge current Ipd into the control threshold value TH and performs current feedback control. The calculation result of the current feedback control is output to the subtraction unit 13 as a control amount CB for correcting the discharge power limit value Wout of the battery 10.

[0060] Subtraction unit 13 subtracts control amount CB output from feedback control unit 12 from discharge power limit value Wout, and outputs the calculation result to motor power calculation unit 14 as correction value Wout* of discharge power limit value Wout (Wout*=Wout−CB).

[0061] The motor power calculation unit 14 receives the accelerator operation amount ACC from the accelerator position sensor 91 and the vehicle speed V from the vehicle speed sensor 92. Based on the accelerator operation amount ACC, the vehicle speed V, etc., the motor power calculation unit 14 calculates the motor power Pm1 required for the first motor generator 61 and the motor power Pm2 required for the second motor generator 62. When the total value (Pm1+Pm2) of the motor powers Pm1, Pm2 exceeds the correction value Wout*, the total value (Pm1+Pm2) is limited to the correction value Wout*.

[0062] The motor torque calculation unit 15 calculates a torque command value TR1 indicating a torque required for the first motor generator 61 based on the motor power Pm1 from the motor power calculation unit 14. Further, the motor torque calculation unit 15 calculates a torque command value TR2 indicating a torque required for the second motor generator 62 based on the motor power Pm2 from the motor power calculation unit 14. Further, the PCU control unit 16 generates a pulse width modulation (PWM) signal for causing the first motor generator 61 and the second motor generator 62 to output torques according to the torque command values ​​TR1, TR2, respectively. Then, the motor torque calculation unit 15 outputs the generated PWM signal to the PCU 50.

[0063] Processing Flow

[0064] Figure 3 : is a flowchart showing a processing procedure performed before current feedback control in this embodiment. Figure 3 The flowchart and Figure 5 and Figure 7The processes shown in the flowcharts in the flowcharts (to be described later) are respectively called from a main routine (not shown) and are executed, for example, every predetermined control cycle. Each step included in these flowcharts is basically implemented by the HV ECU 100 through software processing, but may be implemented by dedicated hardware (circuit) provided in the HV ECU 100. Hereinafter, the term "step" will be abbreviated as "S".

[0065] Reference Figure 3 In S11 , the HV ECU 100 acquires the detection value of the current IB from the current sensor 22 via the battery ECU 40 .

[0066] In S12, the HV ECU 100 acquires the allowable discharge current Ipd of the battery 10 from the battery ECU 40, which is determined to protect the battery 10. The allowable discharge current Ipd is determined according to the temperature TB of the battery 10 and the degradation state of the battery 10, so as to protect the battery 10. Here, the degradation of the battery 10 may include aging of the battery 10. In addition, when the battery 10 is a lithium ion battery, the degradation of the battery 10 may include degradation in which lithium metal is deposited on the negative electrode surface of the lithium ion battery (so-called lithium deposition).

[0067] In S13, the HV ECU 100 sets the allowable discharge current Ipd as a control threshold TH for current feedback control (TH=Ipd).

[0068] In S14, the HV ECU 100 sets the control gain G of the current feedback control. For example, the HV ECU 100 sets the control gain G to a predetermined value. Then, the HV ECU 100 performs the current feedback control using the control threshold TH and the control gain G set in S13 and S14 (S15). Specifically, when the current IB exceeds the control threshold TH, the HV ECU 100 uses the value obtained by subtracting the control threshold TH from the current IB as the control input (control amount CB) and uses a predetermined value as the control gain G to perform feedback control (e.g., proportional integral (PI) control).

[0069] As described above, in the present embodiment, the HV ECU 100 does not receive the discharge power limit value Wout of the battery 10 from the battery ECU 40. When the detection value (current IB) of the current sensor 22 exceeds the control threshold value TH, the HV ECU 100 performs current feedback control to correct the discharge power limit value Wout of the battery 10 based on the amount by which the detection value exceeds the control threshold value TH. The allowable discharge current Ipd output from the battery ECU 40 to the HV ECU 100 is used as the control threshold value TH. Therefore, the HV ECU 100 can perform current limitation so that the current IB does not greatly exceed the control threshold value TH even when the information based on power (discharge power limit value Wout) is not output from the battery ECU 40 to the HV ECU 100.

[0070] First Amendment

[0071] In the present modification, description will be given of control that implements both protection of the battery 10 and protection of electrical components other than the battery 10. In the first modification, the HV ECU 100A is used instead of the HV ECU 100.

[0072] Figure 4 is a functional block diagram of the HV ECU 100A related to the current feedback control in the first modification. Figure 4 , the HVECU 100A is different from the HV ECU 100 according to the embodiment (refer to Figure 2 ) is different from that it further includes an upper limit current storage unit 17.

[0073] The upper limit current storage unit 17 stores an "upper limit current Iu" which is a current determined from the perspective of protecting the electrical components electrically connected between the battery 10 and the PCU 50. The upper limit current Iu is determined in advance based on the rated current of the wiring harness, the rated current of the fuse provided in the battery 10, and the like. However, the electrical components related to the upper limit current Iu are not limited to these examples, but may be, for example, a diode (a device connected in anti-parallel to a switching element) constituting a converter inside the PCU 50. The upper limit current storage unit 17 outputs the upper limit current Iu to the feedback control unit 12.

[0074] Similar to the embodiment, when the detection value of the current IB exceeds the control threshold value TH, the feedback control unit 12 performs current feedback control, which controls the current so that the current IB does not exceed the control threshold value TH. However, in the first modification, the feedback control unit 12 receives not only the allowable discharge current Ipd of the battery 10 from the battery ECU 40, but also the upper limit current Iu from the upper limit current storage unit 17. The feedback control unit 12 substitutes the smaller one of the allowable discharge current Ipd and the upper limit current Iu into the control threshold value TH, and performs current feedback control. The calculation result of the current feedback control is output to the subtraction unit 13 as a control amount CB for correcting the discharge power limit value Wout of the battery 10.

[0075] Figure 5 : is a flowchart showing a processing procedure performed before current feedback control in the first modification. Figure 5 The HV ECU 100A first acquires the detection value of the current IB from the current sensor 22 ( S21 ). In S22 , the HV ECU 100A acquires the allowable discharge current Ipd of the battery 10 , which is determined to protect the battery 10 , from the battery ECU 40 .

[0076] In S23, the HV ECU 100A reads the upper limit current Iu determined for protecting the electrical components from the memory 102. As described above, the upper limit current Iu is a fixed value determined in advance for protecting the wiring harness, fuse, diode, and the like.

[0077] In S24, the HV ECU 100A compares the allowable discharge current Ipd with the upper limit current Iu, and determines whether the allowable amplified current Ipd is less than the upper limit current Iu. When the allowable discharge current Ipd is less than the upper limit current Iu (Yes in S24), the HV ECU 100A proceeds with the process to S25, and sets the allowable discharge current Ipd to the control threshold value TH (TH=Ipd) for current feedback control. On the other hand, when the upper limit current Iu is equal to or less than the allowable discharge current Ipd (No in S24), the HV ECU 100A proceeds with the process to S26, and sets the upper limit current Iu to the control threshold value TH (TH=Iu).

[0078] The subsequent processing of S27 and S28 is similar to that of S14 and S15 in the embodiment (refer to Figure 3 ) is similar to the processing of , so its detailed description will be omitted.

[0079] As described above, in the first modification, similar to the embodiment, current limitation can also be performed so that the current IB does not greatly exceed the control threshold TH even when the discharge power limit value Wout is not output from the battery ECU 40 to the HV ECU 100A. In the first modification, the smaller one of the allowable discharge current Ipd for protecting the battery 10 and the upper limit current Iu determined in advance for protecting the electrical components is used as the control threshold TH. Therefore, both the battery 10 and the electrical components can be appropriately protected.

[0080] Second Amendment

[0081] In the current feedback control, the higher the control gain G is set, the stronger the feedback effect is, and the less the current IB exceeds the control threshold value TH. On the other hand, when the control gain G is set to a value that is too high, the current limit becomes quite strict, and the running-performance of the vehicle 9 may deteriorate. When the control gain G is not set high enough, the feedback effect is weak, and the current IB may exceed the control threshold value TH to a relatively large extent (overshoot). In the second modification, a configuration example will be described in which a measure for the overshoot of the current IB is added. In the second modification, the HV ECU 100B is used instead of the HVECU 100.

[0082] Figure 6 1 shows the time variation of the current IB and the allowable discharge current Ipd of the battery 10. Figure 6 , the horizontal axis represents the elapsed time, and the vertical axis represents the current.

[0083] Reference Figure 6 In the second modification, a margin α is provided for the tolerable discharge current Ipd. The margin α is determined in advance and stored in the memory 102 of the HV ECU 100B. For example, the margin α can be set to about 1 / 10 of the tolerable discharge current Ipd. When the current IB reaches a value (Ipd-α) that is smaller than the tolerable discharge current Ipd by the margin α at time t1, the discharge power limit value Wout is corrected. This can suppress the occurrence of a state in which the current IB exceeds the tolerable discharge current Ipd, and eliminate the state in which the current IB exceeds the tolerable discharge current Ipd in a short time.

[0084] Figure 7 : is a flowchart showing a processing procedure performed before current feedback control in the second modification. Figure 7 , the HV ECU 100B first acquires the detection value of the current IB from the current sensor 22 (S31). Further, the HV ECU 100B acquires the allowable discharge current Ipd of the battery 10 from the battery ECU 40 (S32).

[0085] In S33, the HV ECU 100B reads the margin α provided for the permissible discharge current Ipd from the memory 102. Further, in S34, the HV ECU 100B reads the upper limit current Iu determined in advance from the memory 102.

[0086] In S35, the HV ECU 100B compares the value (Ipd-α) obtained by subtracting the margin α from the allowable discharge current Ipd with the upper limit current Iu. When the difference (Ipd-α) is smaller than the upper limit current Iu (Yes in S35), the HV ECU 100B sets (Ipd-α) as the control threshold TH for current feedback control (S36). On the other hand, when the upper limit current Iu is equal to or smaller than the difference (Ipd-α) (No in S35), the HV ECU 100B sets the upper limit current Iu to the control threshold TH (S37).

[0087] The subsequent processing of S38 and S39 is similar to that of S14 and S15 in the embodiment (refer to Figure 3 ) is similar, so its description will be omitted.

[0088] As described above, in the second modification, similar to the embodiment or the first modification, current limitation can also be performed so that even when the discharge power limit value Wout is not output from the battery ECU 40 to the HV ECU 100B, the current IB does not greatly exceed the control threshold value TH. In the second modification, when the HV ECU 100B receives the allowable discharge current Ipd from the battery ECU 40, the HV ECU 100B sets the control threshold value TH using the value (Ipd-α) obtained by subtracting the margin α from the allowable amplified current Ipd. As a result, when the current IB reaches (Ipd-α), the current feedback control (correction of the discharge power limit value Wout) is started. Therefore, even when the control gain G is relatively low and an overshoot of the current IB may occur, the current IB can be suppressed from greatly exceeding the allowable discharge current Ipd. As a result, according to the second modification, the battery 10 can be protected more effectively.

[0089] The embodiments disclosed herein should be considered as illustrative and non-limiting in all aspects. The scope of the present disclosure is described by the claims rather than the embodiments described above, and it is intended that all modifications are included in the same meaning and scope as the claims.

Claims

1. A driving control system for a vehicle, the vehicle comprising a battery pack, the battery pack comprising a battery, a current sensor configured to detect a current for charging and discharging the battery, and a first control device for monitoring a state of the battery, the driving control system comprising: a rotating electric machine configured to consume electric power to generate driving force and configured to generate electric power; a power conversion device electrically connected between the battery and the rotating electric machine; as well as A second control device, wherein: The second control means has a power limit value indicating the electric power allowed to be charged to and discharged from the battery; and The second control device is configured to: receive the tolerable current of the battery from the first control device, use the tolerable current as the control threshold, and when the detection value of the current sensor exceeds the control threshold, use the value obtained by subtracting the control threshold from the detection value as the control amount to perform the current feedback control to correct the power limit value by subtracting the control amount from the power limit value, and is configured to control the power conversion device, the tolerable current being determined to protect the battery.

2. The driving control system according to claim 1, characterized in that: The second control means is configured to perform the current feedback control using, as the control threshold value, a value obtained by subtracting a predetermined margin from the allowable current.

3. The driving control system according to claim 1, characterized in that: The second control device is configured to perform the current feedback control using, as the control threshold, a smaller one of an upper limit current determined to protect an electrical component electrically connected between the battery and the power conversion device and the allowable current.

4. A vehicle, characterized in that include: A driving control system according to any one of claims 1 to 3.

5. A travel control method for a vehicle, the vehicle comprising a battery pack and a travel control system, the battery pack comprising a battery, a current sensor configured to detect a current for charging and discharging the battery, and a first control device for monitoring a state of the battery, and the travel control system comprising: a rotating electric machine configured to consume electric power to generate driving force and configured to generate electric power; a power conversion device electrically connected between the battery and the rotating electric machine; and a second control device, the second control device controlling the power conversion device, wherein the driving control method is characterized by comprising: outputting an allowable current of the battery from the first control device to the second control device, the allowable current being determined to protect the battery; as well as With the second control means, current feedback control is performed using the allowable current as a control threshold, wherein The current feedback control is: when the detection value of the current sensor exceeds the control threshold value, using a value obtained by subtracting the control threshold value from the detection value as a control amount to correct the power limit value by subtracting the control amount from the power limit value, the power limit value indicating the power allowed to be charged to and discharged from the battery.

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