Vehicle driving control system, vehicle and vehicle driving control procedures

Abstract

Driving control system for a vehicle, wherein the vehicle comprises a battery pack (1), and the battery pack (1) comprises a battery (10), a current sensor (22) configured to detect a current charging and discharging to and from the battery (10), and a first control device (40) monitoring a state of the battery (10), wherein the driving control system comprises: a rotating electric machine configured to use electrical energy to generate a driving force, and configured to generate electrical energy; a power conversion device (50) which is electrically connected between the battery (10) and the rotating electric machine; and a second control device (100), wherein: the second control device (100) has a power limit that specifies an electrical power that is permissible to be charged to and discharged from the battery (10), and is configured to perform feedback current control when a detection value of the current sensor (22) exceeds a control threshold in order to correct the power limit based on an amount by which the detection value exceeds the control threshold, and is configured to control the power converter device (50); the second control device (100) is configured to receive a permissible current from the battery (10) from the first control device (40) and to use the permissible current as the control threshold to perform the feedback current control, whereby the permissible current is determined to protect the battery (10); and the second control device (100) is configured to perform the feedback current control using a smaller, upper limit current, which is determined to protect an electrical component that is electrically connected between the battery (10) and the power converter device (50), and the allowable current, than the control threshold value.

Description

Background of the invention 1. Field of the invention

[0001] The present disclosure relates to a vehicle control system, a vehicle and a vehicle control method, and in particular to a vehicle control system for a vehicle equipped with a battery or accumulator. 2. Description of the state of the art

[0002] In recent years, the use of vehicles equipped with batteries, such as hybrid and electric vehicles, has become widespread. These vehicles will also be referred to as "electric vehicles" below. A typical electric vehicle is equipped with a variety of electronic control units (ECUs) that differ in their function. For example, a hybrid vehicle disclosed in the Japanese unexamined patent application JP 2009-156007A comprises a machine ECU, a motor ECU, a battery ECU, and a hybrid vehicle (HV) ECU. The HV ECU is connected to the machine ECU, the motor ECU, and the battery ECU via communication interfaces and sends and receives various control signals and data to and from these ECUs.

[0003] Furthermore, JP 2016-205917A discloses a secondary battery system comprising a lithium-ion secondary battery configured to be charged by the regenerative electrical power of a vehicle, as well as an HV-ECU and a battery ECU for estimating the deterioration level (battery year Y) of the lithium-ion secondary battery based on the amount of lithium deposited on the negative electrode of the lithium-ion secondary battery. A battery diagnostic request is issued when the estimated deterioration level reaches a threshold.If no anomaly occurs with respect to the vehicle's regenerative control, the HV-ECU and the battery-ECU issue a battery diagnostic request if an increase in the degree of deterioration reaches the threshold within a prescribed period, and if the anomaly occurs, the HV-ECU and the battery-ECU issue a battery diagnostic request regardless of the prescribed period when the degree of deterioration reaches the threshold. Summary of the invention

[0004] The following assumes a configuration in which a battery pack and a vehicle control system are mounted on an electric vehicle. The battery pack comprises an accumulator or battery, a current sensor that detects the current flowing to and from the battery, and an ECU that monitors the battery's state of charge (hereinafter referred to as the first ECU). The vehicle control system comprises a rotating electric machine (motor-generator) capable of consuming electrical energy to generate propulsion and generating electrical energy, a power converter device (inverter, etc.) electrically connected between the battery and the rotating electric machine, and an ECU that controls the power converter 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.

[0005] The automotive industry follows a vertically integrated industrial structure. However, with the further global spread of electric vehicles, there is a possibility that horizontal division of labor regarding electric vehicles will progress in the future.

[0006] It is conceivable that a business unit dealing with battery packs (hereinafter referred to as Company A) and a business unit dealing with vehicle control systems (hereinafter referred to as Company B) operate separately. For example, Company B sells a vehicle control system to Company A. Company A develops an electric vehicle, combining the vehicle control system purchased from Company B with a battery pack developed by Company A. Particularly in such a situation, compatibility between the battery pack and the vehicle control system can become a problem.

[0007] More specifically, Company A has experience with "current-based" protection using batteries based on the conventions of secondary battery research and development. Company B, on the other hand, is familiar with "current-based" control of the charging / discharging process of batteries, which is suitable for controlling power converter devices such as inverters. In such circumstances, the question arises as to which types of parameters should be used for communication between the first ECU in the battery pack and the second ECU in the vehicle control system.

[0008] Specifically, it is conceivable that the first ECU could output an actual charging and discharging current to and from the battery (the current sensor reading) and a "permissible current," which is a current allowed for charging and discharging the battery while considering battery protection. It is desirable for the second ECU to control the power converter device based on the permissible current received from the first ECU, rather than the power-dependent parameters (power limits Win and Wout, described later).

[0009] It is an object of the present invention to ensure compatibility between the two ECUs.

[0010] The problem is solved according to the invention by a driving control system according to claim 1, a vehicle according to claim 2, and a driving control method according to claim 3.

[0011] A vehicle control system according to one aspect of the present disclosure is a vehicle control system for a vehicle with a battery pack. The battery pack comprises a battery, a current sensor configured to detect current to and from the battery, and a first control device that monitors the battery's state. The vehicle control system comprises a rotating electric machine, a power converter device, and a second control device. The rotating electric machine is configured to consume electrical energy and generate motive power, and is also configured to generate electrical energy. The power converter device is electrically connected between the battery and the rotating electric machine.The second control device has a power limit that specifies the electrical power permissible for charging and discharging to and from the battery. It is configured to perform feedback current control when a current sensor reading exceeds a control threshold. This adjustment corrects the power limit based on the amount by which the reading exceeds the control threshold. The second control device also controls the power converter. Furthermore, it is configured to receive a permissible battery current from the first control device and uses this permissible current as the control threshold for the feedback current control. The permissible current is determined to protect the battery.

[0012] According to the configuration above, the second control device is configured to perform feedback current control when the current sensor reading exceeds the control threshold. This corrects the battery's power limit (discharge power limit Wout, described later) based on the amount by which the reading exceeds the control threshold. The control threshold is the allowable current output from the first control device to the second control device. Therefore, the second control device can perform feedback current control and appropriately limit the power limit even when power-based information (power limit) is not output to the second control device by the first.Therefore, compatibility between the two control devices (first and second control device) can be ensured.

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

[0014] According to the above configuration, it is possible to protect the electrical component (such as a wiring harness in the examples described later) with the upper limit, as well as to protect the battery or accumulator with the permissible current.

[0015] A vehicle according to a second aspect of the present disclosure comprises the driving control system, the battery, the current sensor and the 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 vehicle control method. The vehicle comprises a battery pack and a vehicle control system. The battery pack includes a battery, a current sensor configured to detect current charging and discharging to and from the battery, and a first control device that monitors the battery's state. The vehicle control system comprises a rotating electric machine configured to consume electrical energy to generate motive power and to generate electrical energy, a power converter electrically connected between the battery and the rotating electric machine, and a second control device that controls the power converter.The vehicle control method comprises outputting a permissible current from the battery from the first control device to the second control device, the permissible current being determined to protect the battery, and performing, with the second control device, a feedback current control using the permissible current as a control threshold. The feedback current control is a control for correcting, when a current sensor reading exceeds the control threshold, a power limit based on the amount by which the reading exceeds the control threshold, where the power limit specifies an electrical power that is permissible to be charged to and discharged from the battery.The feedback current control uses a smaller, upper limit current, which is determined to protect an electrical component that is electrically connected between the battery and the power converter device, and a lower allowable current than the control threshold.

[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 invention are described below with reference to the attached drawings, in which the same reference numerals denote the same elements, and in which the following applies: Fig. Figure 1 is a representation that schematically shows an overall configuration of a vehicle in the present embodiment; Fig. Figure 2 is a functional block representation of a hybrid vehicle (HV) ECU with respect to a feedback current control in the present embodiment; Fig. Figure 3 is a flowchart showing process procedures that are performed before the feedback current control in the present embodiment; Fig. Figure 4 is a functional block representation of an HV-ECU with respect to a feedback current control in a first modification; Fig. Figure 5 is a flowchart showing process procedures that are performed prior to the feedback current control in the first modification; Fig. Figure 6 shows an example of a temporary change in the current and permissible discharge current of a battery or accumulator; and Fig. Figure 7 is a flowchart showing process procedures that are performed before the feedback current control in a second modification. Detailed description of implementation examples

[0021] Exemplary embodiments of the present disclosure are described in detail with reference to the drawings. It should be noted that the same or corresponding parts in the drawings are designated with the same reference numerals, and a repeated description of these is omitted.

[0022] Below, a configuration in which a driving control system according to the present disclosure is mounted on a hybrid vehicle is described as an example. However, the driving control system according to the present disclosure can be mounted on other types of electric vehicles (electric cars, fuel cell vehicles, etc.). Example of overall vehicle configuration

[0023] Fig. Figure 1 is a schematic representation showing an overall configuration of a vehicle in the present embodiment. Referring to Fig. 1, a vehicle 9 is a hybrid vehicle and comprises a battery pack 1 and a hybrid vehicle (HV) system 2. The HV system 2 can be considered the “driving control system” according to the present disclosure.

[0024] The battery pack 1 comprises 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 comprises a power control unit (PCU) 50, a first motor generator (MG) 61, a second motor generator 62, a machine 70, a power distribution device 81, a drive shaft 82, drive wheels 83, an accelerator pedal position sensor 91, a vehicle speed sensor 92, and an HV ECU 100.

[0025] The battery 10 comprises a composite battery consisting of multiple cells. Each cell is a secondary battery, such as a lithium-ion battery or a nickel-metal hydride battery. The battery 10 stores electrical energy to drive the first motor-generator 61 and the second motor-generator 62, and supplies this electrical energy to the first motor-generator 61 and the second motor-generator 62 via the PCU 50. Furthermore, the battery 10 is charged by absorbing the energy generated by the PCU 50 when the first motor-generator 61 and the second motor-generator 62 generate electrical energy.

[0026] The battery sensor group 20 comprises a voltage sensor 21, a current sensor 22, and a temperature sensor 23. The voltage sensor 21 detects a voltage VB of each cell contained in the battery 10. The current sensor 22 detects a current IB charging and discharging to and from the battery 10. The temperature sensor 23 detects a temperature TB of the battery 10. The sensors output the detection results to the battery ECU 40.

[0027] The SMR 30 is electrically connected to a power line that links battery 10 and PCU 50. The SMR 30 switches the electrical connection and disconnection between PCU 50 and battery 10 according to a control instruction from HV-ECU 100.

[0028] The battery ECU 40 comprises a processor 41, such as a central processing unit (CPU), a memory 42, such as a read / write memory (ROM) and a read / write memory (RAM), and an input / output connector (not shown) for inputting / outputting various signals. The battery ECU 40 monitors the condition of the battery 10 based on the signals received from the sensors of the battery sensor group 20 and the programs and maps stored in the memory 42.

[0029] The main processes performed by the battery ECU 40 include a calculation process for the permissible charging current Ipin and the permissible discharging current Ipd of the battery 10. The permissible charging current Ipin of the battery 10 is the maximum current that is allowed to be charged to the battery 10 from the perspective of protecting the battery 10. Likewise, the permissible discharging current Ipd of the battery 10 is the maximum current that is allowed to be discharged from the battery 10 from the perspective of protecting the battery 10. The battery ECU 40 outputs the calculated permissible charging current Ipin and the calculated permissible discharging current Ipd to the HV ECU 100. It should be noted that either or both of the permissible charging current Ipin and the permissible discharging current Ipd can be considered the "permissible current" according to the present disclosure.

[0030] The PCU 50 performs bidirectional power conversion between the battery 10 and the first and second motor generators 61, 62, or between the first motor generator 61 and the second motor generator 62, according to a control instruction from the HV-ECU 100. The PCU 50 is configured to be able to control the states of the first motor generator 61 and the second motor generator 62 individually. Specifically, the PCU 50 includes, for example, two inverters (not shown), one for the first motor generator 61 and one for 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 bring the second motor generator 62 into the power driving state while the first motor generator 61 is brought into the regenerative state (energy generation state).

[0031] The PCU 50 can be considered the “power converter device” according to the present disclosure. However, if the vehicle 9 is configured to be capable of “external charging” to charge the battery 10 with electrical energy supplied from outside (for example, if the vehicle is a plug-in hybrid vehicle), the “power converter device” according to the present disclosure can be a charging device that converts electrical energy from outside the vehicle into charging power for the battery 10.

[0032] Each of the first motor-generator 61 and the second moderator 62 is a rotating alternating current (AC) electric machine, and is, for example, a three-phase AC synchronous motor in which permanent magnets are embedded in a rotor. At least one of the first mode generator 61 and the second motor-generator 62 can be considered the “rotating electric machine” according to the present disclosure.

[0033] The first motor-generator 61 is primarily used as a generator, driven by the machine 70 via the power-sharing device 81. The electrical energy 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 drive the machine 70.

[0034] The second motor-generator 62 primarily functions as an electric motor, driving the drive wheels 83. It is powered by drawing electrical energy from the battery 10 and / or from the electrical energy generated by the first motor-generator 61, and the driving force of the second motor-generator 62 is transmitted to a drive shaft (output shaft) 72. Conversely, when the vehicle is braked or acceleration is reduced on a downhill slope, the second motor-generator 62 operates as a generator to produce regenerative energy. The electrical energy generated by the second motor-generator 62 is supplied to the battery 10 via the PCU 50.

[0035] The machine 70 outputs power by converting combustion energy, which is generated when a mixture of air and fuel is burned, into kinetic energy of a moving element, such as a piston or a rotor.

[0036] The power-sharing device 81 is, for example, a planetary gear device. Although not shown, the power-sharing device 81 comprises a sun gear, a ring gear, a planet gear, and a carrier. The carrier is connected to the machine 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 gears 83 via the drive shaft 82. The planet gear is in mesh with the sun gear and the ring gear. The carrier holds the planet gear so that the planet gear can rotate and turn.

[0037] The accelerator position sensor 91 detects the downward pressure of an accelerator pedal (not shown) by a user as an accelerator actuation pressure ACC, and outputs the detection result to the HV-ECU 100. The vehicle speed sensor 92 detects the rotational speed of the drive shaft 82 as a vehicle speed V, and outputs the detection result to the HV-ECU 100.

[0038] Like the battery ECU 40, the HV-ECU 100 includes a processor 101, such as a CPU, memory 102, such as ROM and RAM, and an input / output connector (not shown). The HV-ECU 100 performs vehicle control of the vehicle 9 based on data from the battery ECU 40 and the programs and maps stored in the memory 102. Details of the control system are described later.

[0039] The battery ECU 40 can be considered the “first control device” according to the present disclosure. The HV-ECU 100 can be considered the “second control device” according to the present disclosure. The HV-ECU 100 can further be divided into a plurality of ECUs (machine ECU, MG-ECU, etc.) via their functions, as described in JP 2019-156007 A. Communication between ECUs

[0040] The automotive industry is generally assumed to have a vertically integrated industrial structure. However, with the increasing global adoption of electric vehicles, there is a possibility that horizontal division of labor regarding electric vehicles will progress. The inventors of the present disclosure have focused on the fact that the following issues may arise as such a transformation of the industrial structure progresses.

[0041] It is conceivable that a business unit dealing with battery pack 1 (hereinafter referred to as Company A) and a business unit dealing with HV system 2 (hereinafter referred to as Company B) operate separately. For example, Company B sells HV system 2 to Company A. Company A develops the vehicle in which the HV system 2 purchased by Company B is combined with the battery pack 1 designed (or procured) by Company A. Particularly in such a situation, compatibility between battery pack 1 and HV system 2 can become a problem.

[0042] More specifically, Company A has experience with current-based protection and the use of battery 10 based on the convention in the field of secondary battery research and development. On the other hand, Company B is familiar with current-based control of the charging / discharging process of battery 10, which is suitable for controlling the PCU 50. For the charging / discharging control of battery 10, Company B uses an upper limit for charging power control (Win), which is the upper limit of the charging power to battery 10, and a limit for discharging power (Wout), which is the upper limit of the discharge power from battery 10. In this case, the HV-ECU 100 only needs to be capable of receiving the upper limit of charging power control (Win) and the discharge power limit (Wout) of battery 10 from the battery ECU 40.However, Company A is not familiar with the technology for outputting the upper limit of the charging power control Win and the limit of the discharging power Wout from the battery ECU 40. Therefore, it may become problematic to determine which types of parameters should be used for communication between the battery ECU 40 and the HV ECU 100 (which current-based and which power-based communication will be used).

[0043] In the present embodiment, it is assumed that the current-based communication is carried out based on the intention of Company A, to which Company B sells the HV system 2. Specifically, as described above, the battery ECU 40 outputs to the HV ECU 100 the permissible charging current Ipin and the permissible discharging current Ipd that are allowed to be applied to and discharged from the battery 10 in order to protect the battery 10. The HV ECU 100 performs the feedback control for the PCU 50 based on the permissible charging current Ipin and the permissible discharging current Ipd received from the battery ECU 40. This control is referred to as "feedback current control" and is described in detail below.

[0044] The feedback current control during charging and discharging of battery 10 is essentially the same. Therefore, the following describes, as a representative example, the feedback current control based on the permissible discharge current Ipd during the discharge of battery 10. Regarding the charging / discharging direction (sign of current and power) of battery 10, the positive direction is defined as the discharge direction, and the negative direction is defined as the charging direction. Feedback current control

[0045] Fig. Figure 2 is a functional block diagram of the HV-ECU 100 with respect to the feedback current control in the present embodiment. Referring to Fig. 2, the HV-ECU 100 comprises 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.

[0046] The Wout storage unit 11 stores the discharge power limit Wout. The discharge power from the battery 10 is limited to prevent exceeding the discharge power limit Wout. The discharge power limit Wout can be a fixed value or a variable value calculated according to the temperature TB and / or the state of charge (SOC) of the battery 10. The Wout storage unit 11 outputs the discharge power limit Wout of the battery 10 to the subtraction unit 13.

[0047] The feedback control unit 12 receives a current reading IB from the battery ECU 40 at regular intervals (e.g., several hundred milliseconds). The battery ECU 40 can perform a smoothing process (gradual change process) on the signal (reading value) from the current sensor 22 and outputs the smoothed value to the feedback control unit 12. The smoothing process is, for example, a process of averaging the readings from the current sensor 22 over a predetermined time constant.

[0048] The feedback control unit 12 is configured to perform feedback current control, ensuring that the current IB falls below a control threshold TH when the current IB is measured and exceeds the control threshold TH. The feedback control unit 12 receives the permissible discharge current Ipd of battery 10 from the battery ECU 40, in addition to the measured current IB. The feedback control unit 12 then substitutes the permissible discharge current Ipd into the control threshold TH and executes the feedback current control. The result of this feedback current control calculation is output to the subtraction unit 13 as a control variable CB to adjust the discharge power limit Wout of battery 10.

[0049] The subtraction unit 13 subtracts the control variable CB, which is output by the feedback control unit 12, from the discharge power limit Wout, and outputs the calculation result to the motor power calculation unit 14 as a correction value Wout* of the discharge power limit Wout (Wout* = Wout - CB).

[0050] The engine power calculation unit 14 receives the accelerator pedal actuation magnitude ACC from the accelerator position sensor 91 and the vehicle speed V from the vehicle speed sensor 92. Based on the accelerator pedal actuation magnitude ACC, the vehicle speed V, and other relevant data, the engine power calculation unit 14 calculates an engine power Pm1 required for the first motor generator 61 and an engine power Pm2 required for the second motor generator 62. If the total value (Pm1 + Pm2) of the engine power Pm1, Pm2 exceeds the correction value Wout*, the total value (Pm1 + Pm2) is limited to the correction value Wout*.

[0051] The motor torque calculation unit 15 calculates a torque instruction value TR1, which specifies the torque required for the first motor generator 61, based on the motor power Pm1 from the motor power calculation unit 14. Furthermore, the motor torque calculation unit 15 calculates a torque instruction value TR2, which specifies the torque required for the second motor generator 62, based on the motor power Pm2 from the motor power calculation unit 14. The PCU control unit 16 then generates a pulse width modulation (PWM) signal to cause the first motor generator 61 and the second motor generator 62 to output torque according to the torque instruction values ​​TR1 and TR2, respectively. The motor torque calculation unit 15 then outputs the generated PWM signal to the PCU 50. Process flow

[0052] Fig. Figure 3 is a flowchart showing process procedures that are performed before the feedback current control in the present embodiment. The flowchart in Fig. 3 and the flowcharts in Fig. 5 and Fig. The seven processes shown, which will be described later, are each called by a main routine (not shown) and executed, for example, at each predetermined control cycle. Each step included in these flowcharts is essentially implemented by software processing by the HV-ECU 100, but may also be implemented by dedicated hardware (electrical circuitry) provided within the HV-ECU 100. Hereinafter, the term "step" is abbreviated as "S".

[0053] Referring to Fig. 3, in S11, the HV-ECU 100 obtains the current IB measurement value from the current sensor 22 via the battery-ECU 40.

[0054] In S12, the HV-ECU 100 receives the permissible discharge current Ipd of battery 10 from the battery-ECU 40. This current is determined to protect battery 10. The permissible discharge current Ipd is determined according to the temperature TB of battery 10 and the battery's wear condition. Battery wear can include deterioration due to aging. Furthermore, if battery 10 is a lithium-ion battery, battery wear can include degradation where lithium metal is deposited on the negative electrode surface of the lithium-ion battery (so-called lithium deposition).

[0055] In S13, the HV-ECU 100 sets the permissible discharge current Ipd (TH = Ipd) as the control threshold TH, which is used for the feedback current control.

[0056] In S14, the HV-ECU 100 sets a control gain G for the feedback current control. For example, the HV-ECU 100 sets the control gain G to a predetermined value. Then, the HV-ECU 100 performs the feedback current control using the control threshold TH and the control gain G set in S13 and S14 (S15). Specifically, the HV-ECU 100 performs feedback control (for example, proportional-integral (PI) control) using a value obtained by subtracting the control threshold TH from the current IB as a control input (control variable CB), and using a predetermined value as the control gain G, when the current IB exceeds the control threshold TH.

[0057] As described above, in the present embodiment, the HV-ECU 100 does not receive the discharge power limit Wout of battery 10 from the battery ECU 40. The HV-ECU 100 performs the feedback current control when the sensing value of current sensor 22 (current IB) exceeds the control threshold TH, in order to correct the discharge power limit Wout of battery 10 based on the amount by which the sensing value exceeds the control threshold TH. The permissible discharge current Ipd, which is output by the battery ECU 40 to the HV-ECU 100, is used as the control threshold TH. Therefore, the HV-ECU 100 can perform current limiting so that the current IB does not significantly exceed the control threshold TH, even if power-based information (discharge power limit Wout) is not output from the battery ECU 40 to the HV-ECU 100. First modification

[0058] The current modification describes a control system for achieving protection of both battery 10 and electrical components other than battery 10. The first modification uses an HV-ECU 100A instead of the HV-ECU 100.

[0059] Fig. Figure 4 is a functional block diagram of the HV-ECU 100A with regard to the feedback current control in the first modification. Referring to Fig. 4. The HV-ECU 100A differs from the HV-ECU 100 (see below). Fig. 2) according to the embodiment, by further including a storage unit of the upper limit current 17.

[0060] The upper limit current storage unit 17 stores an "upper limit current Iu," which is a current determined to protect the electrical components connected between the battery 10 and the PCU 50. The upper limit current Iu is pre-defined based on the rated current of the wiring harness, the rated current of the fuse provided in the battery 10, or similar factors. However, the electrical components with respect to the upper limit current Iu are not limited to these examples and could, for instance, include a diode (a device connected antiparallel to a switching element) forming a converter within the PCU 50. The upper limit current storage unit 17 outputs the upper limit current Iu to the feedback control unit 12.

[0061] As in the exemplary embodiment, the feedback control unit 12 performs the feedback current control, which controls the current such that the current IB does not exceed the control threshold TH when the measured value of the current IB exceeds the control threshold TH. However, in the first modification, the feedback control unit 12 receives not only the permissible 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 of the permissible discharge current Ipd and the upper limit current Iu into the control threshold TH and performs the feedback current control. The result of the feedback current control calculation is output to the subtraction unit 13 as the control variable CB for correcting the discharge power limit Wout of the battery 10.

[0062] Fig. Figure 5 is a flowchart showing process procedures that are executed before the feedback current control in the first modification. Referring to Fig. 5. The HV-ECU 100A first obtains the current value IB from the current sensor 22 (S21). In S22, the HV-ECU 100A obtains the permissible discharge current Ipd of battery 10 from the battery ECU 40, which is determined to protect battery 10.

[0063] In S23, the HV-ECU 100A reads the upper limit current Iu from memory 102, which is used to protect the electrical components. As described above, the upper limit current Iu is a fixed value that is predetermined to protect the wiring harness, fuse, diode, and the like.

[0064] In S24, the HV-ECU 100A compares the permissible discharge current Ipd with the upper limit current Iu and determines whether the permissible discharge current Ipd is less than the upper limit current Iu. If the permissible discharge current Ipd is less than the upper limit current Iu (YES in S24), the HV-ECU 100A proceeds to S25 and sets the permissible discharge current Ipd as the control threshold TH, which is used for the feedback current control (TH = Ipd). Conversely, if the upper limit current Iu is less than or equal to the permissible discharge current Ipd (NO in S24), the HV-ECU 100A proceeds to S26 and sets the upper limit current Iu as the control threshold TH (TH = Iu).

[0065] The subsequent processes of S27 and S28 are the same as the processes of S14 and S15 (see below). Fig. 3) in the exemplary embodiment, and therefore a detailed description of it is omitted.

[0066] As described above, in the first modification, identical to the exemplary embodiment, the current limiting can be implemented such that the current IB does not significantly exceed the control threshold TH, even if the discharge power limit Wout is not output by the battery ECU 40 to the HV ECU 100A. In the first modification, the lower of the permissible discharge current Ipd for the protection of battery 10 and the lower of the upper limit current Iu, which is determined in advance to protect the electrical components, is used as the control threshold TH. This ensures adequate protection for both battery 10 and the electrical components. Second modification

[0067] In the feedback current control, the higher the control gain G is set, the stronger the feedback and the less the current IB exceeds the control threshold TH. Conversely, if the control gain G is set too high, the current limiting becomes excessively strict, and the drivability of the vehicle 9 may deteriorate. If the control gain G is not set high enough, the feedback action is weak, and the current IB may exceed the control threshold TH relatively significantly (overshoot). The second modification describes a configuration example in which measures regarding current IB overshoot are added. In the second modification, an HV-ECU 100B is used instead of the HV-ECU 100.

[0068] Fig. Figure 6 shows an example of a temporary change in the current IB and the permissible discharge current Ipd of battery 10. Fig. 10 represents the horizontal axis as the elapsed time, and the vertical axis as the current.

[0069] Referring to Fig. In the second modification, section 6 provides a range α with respect to the permissible discharge current Ipd. The range α is predefined and stored in memory 102 of the HV-ECU 100B. The range α can, for example, be set to 1 / 10 of the permissible discharge current Ipd. If the current IB reaches a value (Ipd - α) that is less than the permissible discharge current Ipd by the range α at time t1, the correction of the discharge power limit Wout is initiated. This serves to limit the occurrence of the condition in which the current IB exceeds the permissible discharge current Ipd and to eliminate the condition in which the current IB exceeds the permissible discharge current Ipd within a short time.

[0070] Fig. Figure 7 is a flowchart showing process procedures that are executed before the feedback current control in the second modification. Referring to Fig. 7. The HV-ECU 100B first obtains the measured value of the current IB from the current sensor 22 (S31). Furthermore, the HV-ECU 100B obtains the permissible discharge current Ipd of the battery 10 from the battery ECU 40 (S32).

[0071] In S33, the HV-ECU 100B reads the range α provided for the permissible discharge current Ipd from memory 102. Furthermore, in S34, the HV-ECU 100B reads the predetermined upper limit current Iu from memory 102.

[0072] In S35, the HV-ECU 100B compares the value (Ipd - α), obtained by subtracting the span α from the permissible discharge current Ipd, with the upper limit current Iu. If the difference (Ipd - α) is less than the upper limit current Iu (YES in S35), the HV-ECU 100B sets (Ipd - α) as the control threshold TH used for the feedback current control (S36). Conversely, if the upper limit current Iu is less than or equal to the difference (Ipd - α) (NO in S35), the HV-ECU 100B sets the upper limit current Iu as the control threshold TH (S37).

[0073] The subsequent processes of S38 and S39 are the same as the processes of S14 and S15 (see below). Fig. 3) in the exemplary embodiment, and therefore the description of it is omitted.

[0074] As described above, in the second modification, identical to the exemplary embodiment or the first modification, the current limiting can be implemented such that the current IB does not significantly exceed the control threshold TH, even if the discharge power limit Wout is not output by the battery ECU 40 to the HV-ECU 100B. In the second modification, when the HV-ECU 100B receives the permissible discharge current Ipd from the battery ECU 40, the HV-ECU 100B uses the value (Ipd - α), obtained by subtracting the range α from the permissible discharge current Ipd, to set the control threshold TH. As a result, the feedback current control (correction of the discharge power limit Wout) is initiated when the current IB reaches (Ipd - α).Therefore, even if the control gain G is relatively low and current IB overshoot is likely, it is possible to prevent the current IB from significantly exceeding the permissible discharge current Ipd. As a result, according to the second modification, battery 10 can be protected more effectively.

[0075] The disclosed embodiment should in every respect be regarded as illustrative and not limiting. The scope of the present disclosure is shown in the claims instead of the preceding embodiment and is intended to encompass all modifications within the meaning and scope equivalent to those of the claims.

[0076] A vehicle control system and the vehicle comprise a battery pack (1). The battery pack (1) comprises a battery (10), a current sensor (22) configured to detect current charging and discharging to and from the battery (10), and a first control device that monitors the state of the battery (10). The vehicle control system comprises a rotating electric machine configured to consume electrical energy to generate propulsion and to generate electrical energy, a power conversion device electrically connected between the battery (10) and the rotating electric machine, and a second control device.

Claims

[1] A driving control system for a vehicle, the vehicle comprising a battery pack (1), and the battery pack (1) comprising a battery (10), a current sensor (22) configured to detect a current charged and discharged to and from the battery (10), and a first control device (40) monitoring a state of the battery (10), the driving control system comprising: a rotating electric machine configured to use electrical energy to generate a driving force and configured to generate electrical energy; a power conversion device (50) electrically connected between the battery (10) and the rotating electric machine; and a second control device (100), wherein: the second control device (100) has a power limit value indicating an electric power that is permissible to be charged and discharged to and from the battery (10), and is configured to perform feedback current control when a detection value of the current sensor (22) exceeds a control threshold value to correct the power limit value based on an amount by which the detection value exceeds the control threshold value, and is configured to control the power conversion device (50); the second control device (100) is configured to receive a permissible current of the battery (10) from the first control device (40) and to use the permissible current as the control threshold to perform the feedback current control, wherein the permissible current is determined to protect the battery (10); and the second control device (100) is configured to perform the feedback current control using a smaller upper limit current determined to protect an electrical component electrically connected between the battery (10) and the power conversion device (50) and the allowable current than the control threshold. [2] Vehicle with: the driving control system according to claim 1; the battery (10); the current sensor (22); and the first control device (40). [3] A driving control method for a vehicle, the vehicle comprising a battery pack (1) and a driving control system, the battery pack (1) comprising a battery (10), a current sensor (22) configured to detect a current charged and discharged to and from the battery (10), and a first control device (40) that monitors a state of the battery (10), and the driving control system comprises a rotating electric machine configured to use electrical energy to generate a driving force and configured to generate electrical energy, a power converter device (50) electrically connected between the battery (10) of the rotating electric machine, and a second control device (100) that controls the power converter device (50), the driving control method comprising: Outputting a permissible current of the battery (10) from the first control device (40) to the second control device (100), wherein the permissible current is determined to protect the battery (10); and Carrying out, with the second control device (100), a feedback current control using the allowable current as a control threshold, wherein the feedback current control is a controller for correcting, when a detection value of the current sensor (22) exceeds the control threshold, a power limit based on an amount by which the detection value exceeds the control threshold, wherein the power limit indicates an electrical power that is permissible to be charged and discharged to and from the battery (10); and the feedback current control uses a smaller one of an upper limit current determined to protect an electrical component electrically connected between the battery (10) and the power conversion device (50) and the allowable current as the control threshold.

Images