Vehicle control device

Abstract

To provide a vehicle control device capable of suppressing a reduction in a vehicle's travelling distance, even when a generator is brought into a state of an uncontrolled power generation amount due to occurrence of an abnormal state.SOLUTION: A vehicle 10 comprises an engine 12, a generator GE connected to the engine 12, a high-voltage battery 52 capable of exchanging power with the generator GE, a low-voltage battery 56 that supplies power to an auxiliary device 58 that drives the engine 12, and a DC / DC converter 54 provided between the high-voltage battery 52 and the low-voltage battery 56. When the generator GE is brought into a state of an uncontrolled power generation amount due to occurrence of an abnormal state, an electronic control device 90 executes an increase control that raises an engine rotational speed Ne, which is a rotational speed of the engine 12, such that a counter electromotive force Vemf generated by the generator GE becomes equal to or greater than a battery voltage Vbat of the high-voltage battery 52. At the same time, power is supplied from the high-voltage battery 52 to the low-voltage battery 56 via the DC / DC converter 54.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a control device for a vehicle that includes an engine, a generator connected to the engine, a high-voltage battery that can exchange power with the generator, a low-voltage battery that supplies power to accessories that drive the engine, and a DC / DC converter provided between the high-voltage battery and the low-voltage battery. [Background technology]

[0002] There are known control devices for a vehicle that includes an engine, a generator connected to the engine, a high-voltage battery that can exchange power with the generator, a low-voltage battery that supplies power to accessories that drive the engine, a DC / DC converter provided between the high-voltage battery and the low-voltage battery, and an electric motor that is a power source for traveling and is driven by power supplied from the high-voltage battery. For example, one such device is described in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-245009 Summary of the Invention [Problem to be solved by the invention]

[0004] In the vehicle control device described in Patent Document 1, if an abnormality is detected in the electric motor for driving, the electric motor is put into a "non-driving state" in which it is not driven and controlled, thereby minimizing damage to the electric motor. In this case, the low-voltage battery and the auxiliary equipment are supplied with power that is the reduced output voltage of the generator directly or indirectly, so the low-voltage battery and the auxiliary equipment function normally. Therefore, even if the electric motor is put into a non-driving state, the vehicle can still be driven using the engine as a power source for driving.

[0005] For example, if a generator abnormality is detected, one possible way to minimize damage to the generator is to place the generator in a "power generation uncontrolled state," in which the rotor coil excitation current is not adjusted to match the generator's rotational speed. In this case, there is a risk of the generator losing power to the high-voltage battery. Even if the electric motor powered by the high-voltage battery is deactivated, if the high-voltage battery continues to supply power to the low-voltage battery and auxiliary equipment via the DC / DC converter, the amount of charge stored in the high-voltage battery gradually decreases. This could result in the auxiliary battery running out, preventing power from being supplied to the auxiliary equipment, and making it impossible to drive the vehicle using the engine as a power source.

[0006] The present invention has been made against the background of the above circumstances, and its purpose is to provide a vehicle control device that can suppress a decrease in the vehicle's driving distance even if an abnormal condition occurs and the generator is put into a power generation non-control state. [Means for solving the problem]

[0007] The gist of the present invention is a control device for a vehicle that includes an engine, a generator connected to the engine, a high-voltage battery that can exchange power with the generator, a low-voltage battery that has a lower voltage than the high-voltage battery and supplies power to accessories that drive the engine, and a DC / DC converter provided between the high-voltage battery and the low-voltage battery, wherein, when an abnormal condition occurs and the generator is placed in a power generation uncontrolled state, an increase control is performed to increase the rotational speed of the engine so that the back electromotive force generated by the generator is equal to or greater than the voltage of the high-voltage battery, and power is supplied from the high-voltage battery to the low-voltage battery via the DC / DC converter. [Effects of the Invention]

[0008] According to the present invention, when the generator is placed in a power generation uncontrolled state due to the occurrence of an abnormality, an increase control is executed to increase the rotational speed of the engine so that the back electromotive force generated by the generator is equal to or greater than the voltage of the high-voltage battery, and power is supplied from the high-voltage battery to the low-voltage battery via the DC / DC converter. In this way, when the generator is placed in a power generation uncontrolled state, an increase control is executed so that the back electromotive force generated by the generator is equal to or greater than the voltage of the high-voltage battery, and the DC / DC converter continues to supply power from the high-voltage battery to the low-voltage battery. This suppresses a decrease in the amount of charge stored in the high-voltage battery and the occurrence of a dead auxiliary battery, thereby suppressing a decrease in the vehicle's mileage. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a vehicle equipped with an electronic control device according to an embodiment of the present invention, and is also a functional block diagram showing the main parts of control functions for various controls in the vehicle. [Figure 2] 2 is an explanatory diagram of the high-voltage battery, inverter, generator, DC / DC converter, and battery system ECU shown in FIG. 1. FIG. [Figure 3] 2 is an example of a flowchart illustrating a main part of the control operation of the electronic control device shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of the various parts are not necessarily drawn accurately. [Example]

[0011] FIG. 1 is a schematic diagram of a vehicle 10 equipped with an electronic control device 90 according to an embodiment of the present invention, and is also a functional block diagram showing the main parts of control functions for various controls in the vehicle 10.

[0012] The vehicle 10 is equipped with, in order from the engine 12 side, a transmission 14 and a front wheel differential 16 in a power transmission path between the engine 12 and a pair of front wheels 18, and with a rear wheel differential 26 in a power transmission path between the electric motor MT and a pair of rear wheels 28, all of which are well-known components. The vehicle 10 is also equipped with a belt transmission 40, a generator GE, an inverter 50, a high-voltage battery 52, a DC / DC converter 54, a low-voltage battery 56, accessories 58, a system main relay 62 (hereinafter simply referred to as "relay 62"), and an air compressor AC, all of which are well-known components. The vehicle 10 also has an electronic control device 90.

[0013] The engine 12 is a well-known internal combustion engine and is a power source for driving the pair of front wheels 18 of the vehicle 10. The engine 12 controls the engine torque Te [Nm], which is the output torque of the engine 12, by controlling accessories 58 such as a throttle actuator, a fuel injection device, and an ignition device provided on the engine 12 using an electronic control device 90. The accessories 58 are devices for causing the main body of the engine 12 to function. In this specification, unless otherwise specified, the terms torque, power, driving force, and force (power) are synonymous.

[0014] The transmission 14 is configured, for example, by a well-known torque converter or automatic transmission.

[0015] The electric motor MT is a rotating electric machine that has at least the electric motor function of both an electric motor function and a generator function, and is, for example, a so-called three-phase synchronous motor generator. The electric motor MT is a power source for driving the pair of rear wheels 28 of the vehicle 10. The electric motor MT corresponds to the "electric motor" in this invention.

[0016] The generator GE is a rotating electric machine that has at least the generator function of either a motor function or a generator function. The generator GE includes a stator (not shown) and a rotor (not shown). For example, in the generator GE, a stator coil Cs (see FIG. 2) is wound around the stator, and a rotor with a surface magnet or embedded magnet type permanent magnet and a rotor coil Cr (see FIG. 2) is wound around it. The generator GE corresponds to the "generator" in the present invention. When the rotor of the generator GE is rotated, a rotating magnetic field is generated in which the magnetic flux of the permanent magnet and the magnetic flux of the electromagnet formed by the excitation current flowing through the rotor coil Cr rotate. This generates a back electromotive force Vemf in the stator coil Cs, causing the generator GE to generate electricity. Furthermore, when a three-phase AC current is passed through the stator coil Cs, the rotor of the generator GE is rotated. When the generator GE is generating electricity, the generator GE functions as an alternator. When the generator GE outputs an output torque that is a powering torque, the generator GE functions as a starter motor that outputs a cranking torque to the engine 12. The generator GE of this embodiment has both a motor function and a generator function.

[0017] The belt transmission 40 interconnects the engine 12, the generator GE, and the air compressor AC. The belt transmission 40 is a well-known belt-type transmission device including a crank pulley 42 non-rotatably connected to the crankshaft 32 of the engine 12, a generator pulley 44 non-rotatably connected to the rotor shaft 34, which is the rotating shaft of the rotor of the generator GE, an AC pulley 46 non-rotatably connected to the drive shaft 36 of the air compressor AC, and a belt 48 wound around the crank pulley 42, the generator pulley 44, and the AC pulley 46. The crankshaft 32, the rotor shaft 34, and the drive shaft 36 are rotating members whose rotational centers are a first axis CL1, a second axis CL2, and a third axis CL3, respectively. The first axis CL1, the second axis CL2, and the third axis CL3 are parallel to one another. The belt 48 is an endless annular transmission member capable of transmitting power between the engine 12 and the generator GE, and is, for example, an endless annular compression-type transmission belt capable of transmitting power between the crank pulley 42 and the generator pulley 44, or an endless annular tension-type transmission belt.

[0018] The generator GE is connected to a high-voltage battery 52 via an inverter 50. The inverter 50 is a power supply circuit that is controlled by an electronic control device 90 to convert direct current to alternating current and vice versa. For example, the inverter 50 controls the excitation current Icr flowing through the rotor winding Cr of the generator GE by PWM (Pulse Width Modulation) control of the direct current supplied from the high-voltage battery 52, and converts the three-phase alternating current Wge generated by the generator GE into direct current and outputs it to the high-voltage battery 52. ​​The inverter 50 also converts the direct current supplied from the high-voltage battery 52 into three-phase alternating current and controls the excitation current Ics flowing through the stator winding Cs of the generator GE.

[0019] The electronic control device 90 controls the inverter 50, thereby adjusting the excitation current Icr [Nm] of the generator GE. The excitation current Icr is adjusted, for example, according to the generator rotational speed Nge [rpm], which is the rotational speed of the generator GE. For a given excitation current Icr, the higher the generator rotational speed Nge, the greater the generated power Wge. For a given generator rotational speed Nge, the greater the generated power Wge, the greater the excitation current Icr. Therefore, in order to obtain the required generated power Wge, the excitation current Icr is adjusted to be larger when the generator rotational speed Nge is relatively low, and the excitation current Icr is adjusted to be smaller when the generator rotational speed Nge is relatively high.

[0020] The high-voltage battery 52 is a secondary battery that can be charged and discharged. The high-voltage battery 52 is used to supply power to the electric motor MT and the generator GE, and to charge the electric power Wmt generated by the electric motor MT and the electric power Wge generated by the generator GE through regeneration. The high-voltage battery 52 is a battery that can exchange electric power with the generator GE.

[0021] The low-voltage battery 56 is a secondary battery that can be charged and discharged. The low-voltage battery 56 is used to supply power to electrical loads including accessories 58 (for example, a throttle actuator, a fuel injection device, an ignition device, various sensors, switches, etc.). Due to the difference in use, the low-voltage battery 56 has a lower voltage than the high-voltage battery 52. ​​That is, the battery voltage Vbat of the high-voltage battery 52 is higher than that of the low-voltage battery 56. For example, the low-voltage battery 56 has a voltage of 12 V, while the high-voltage battery 52 has a higher voltage. The battery voltage Vbat is the battery voltage of the high-voltage battery 52 and corresponds to the "voltage of the high-voltage battery" in this invention.

[0022] The DC / DC converter 54 is a power supply circuit that is provided between the high-voltage battery 52 and the low-voltage battery 56 and that increases or decreases the voltage of direct current. For example, the DC / DC converter 54 decreases the voltage of the direct current supplied from the high-voltage battery 52 and outputs the direct current having a lower voltage than that of the high-voltage battery 52 to the low-voltage battery 56.

[0023] The relay 62 is a switch that connects and disconnects the power supply between the high-voltage battery 52 and the inverter 50 and the DC / DC converter 54.

[0024] Air compressor AC is a well-known air compressor.

[0025] Here, the crank pulley 42 has a radius R1 [mm], the generator pulley 44 has a radius R2 [mm], and the value obtained by dividing the radius R2 by the radius R1 is the predetermined rotation ratio α (= R2 / R1) in the belt transmission device 40.

[0026] The air compressor AC can be switched between an operating state and a stopped state. For example, the AC pulley 46 is connected to the drive shaft 36 of the air compressor AC via a clutch (not shown). When the clutch is engaged, the rotation of the AC pulley 46 is transmitted to the drive shaft 36, putting the air compressor AC into an operating state. When the clutch is released, the AC pulley 46 rotates freely relative to the drive shaft 36, putting the air compressor AC into a stopped state.

[0027] The electronic control unit 90 includes a drive system ECU 92 and a battery system ECU 94 that function as control devices for controlling various components of the vehicle 10. The electronic control unit 90 corresponds to the "control device" in the present invention. The drive system ECU 92 is an ECU that primarily controls the operation of the drive system, which includes the engine 12, transmission 14, and electric motor MT of the vehicle 10. The battery system ECU 94 is an ECU that primarily controls the operation of the battery system, which includes the generator GE, relay 62, and DC / DC converter 54. For example, the drive system ECU 92 and battery system ECU 94 in the electronic control unit 90 are connected to a communication network using a CAN (Controller Area Network) communication circuit. This allows data to be exchanged between the ECUs. Each ECU includes a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input / output interface, etc. The CPU executes various controls of the vehicle 10 by utilizing the temporary storage function of the RAM and performing signal processing according to programs previously stored in the ROM.

[0028] The drive system ECU 92 receives inputs of various signals (e.g., engine rotation speed Ne [rpm] which is the rotation speed of the engine 12, electric motor rotation speed Nmt [rpm] which is the rotation speed of the electric motor MT, vehicle speed V [km / h], accelerator opening θacc [%] which is the acceleration operation amount which indicates the magnitude of the acceleration operation by the driver) based on detection values ​​from various sensors provided on the vehicle 10 (e.g., engine rotation speed sensor 70, electric motor rotation speed sensor 72, vehicle speed sensor 74, accelerator opening sensor 76, etc.). The electric motor rotation speed sensor 72 is, for example, a resolver which can detect a phase which indicates the rotation position of the rotor of the electric motor MT, i.e., which can detect the rotation angle and rotation speed.

[0029] The battery system ECU 94 receives various signals (e.g., generator rotation speed Nge [rpm] which is the rotation speed of the generator GE, generator temperature THge which is the temperature of the generator GE, inverter temperature THinv which is the temperature of the inverter 50, etc.) based on detection values ​​from various sensors (e.g., generator rotation speed sensor 80, battery voltage sensor 82, generator temperature sensor 84, inverter temperature sensor 86, etc.) provided in the vehicle 10. The generator rotation speed sensor 80 is, for example, a resolver that can detect a phase that indicates the rotational position of the rotor of the generator GE, i.e., that can detect the rotation angle and rotation speed.

[0030] The drive system ECU 92 outputs various command signals (e.g., an engine control signal Se for controlling the engine 12, a shift control signal Stm for executing shift control of the transmission 14, an electric motor control signal Smt for executing rotation control of the electric motor MT via the inverter 50, etc.) to each device (e.g., the engine 12, the transmission 14, the inverter 50, etc.) provided in the vehicle 10.

[0031] The battery system ECU 94 outputs various command signals (e.g., a generator control signal Sge for controlling the excitation current Icr and the excitation current Ics of the generator GE via the inverter 50, a relay control signal Srly for controlling the opening and closing of the relay 62, a converter control signal Scon for controlling the voltage conversion of the DC / DC converter 54, etc.) to each device provided in the vehicle 10 (e.g., the inverter 50, the relay 62, the DC / DC converter 54, etc.).

[0032] Next, we will explain the case where the generator GE is put into a power generation non-control state due to the occurrence of an abnormal state. In the generator GE, the "power generation control state" refers to a state in which the excitation current Icr is adjusted and controlled according to the generator rotation speed Nge, and the "power generation non-control state" refers to a state in which the excitation current Icr is set to a predetermined constant value (for example, zero) regardless of the generator rotation speed Nge.

[0033] The drive system ECU 92 functionally includes an engine control unit 92a, a transmission control unit 92b, and an electric motor control unit 92c. The battery system ECU 94 functionally includes a generator control unit 94a, a relay control unit 94b, a converter control unit 94c, an abnormal state determination unit 94d, a battery voltage determination unit 94e, a running state determination unit 94f, and a rotation control feasibility determination unit 94g.

[0034] While the vehicle is traveling, the engine control unit 92a controls the engine torque Te, the gear change control unit 92b executes gear change control of the transmission 14, and the electric motor control unit 92c controls the electric motor torque Tmt, which is the torque of the electric motor MT, so as to realize the required driving torque Trdem for the vehicle 10. The required driving torque Trdem is the driving torque that the driver requests for the vehicle 10. The required driving torque Trdem is calculated, for example, by applying the actual accelerator opening θacc and the actual vehicle speed V to a map in which the relationship between the accelerator opening θacc, the vehicle speed V, and the required driving torque Trdem is determined in advance experimentally or by design and stored.

[0035] In controlling the power generation of the generator GE, the generator control unit 94a adjusts the excitation current Icr so that the generator GE can obtain the required generated power Wge using the power of the engine 12. In other words, the generator control unit 94a puts the generator GE into a power generation amount control state.

[0036] The relay control unit 94b controls the open / close state of the relay 62.

[0037] The converter control unit 94c controls the switching of the operating state of the DC / DC converter 54 between an operating state and a stopped state.

[0038] The abnormality determination unit 94d determines whether an abnormality has occurred that requires the generator GE to be placed in a power generation uncontrolled state. For example, if the generator temperature THge exceeds a predetermined temperature determination value THge_jdg, it is determined that an abnormality has occurred. The predetermined temperature determination value THge_jdg is a determination value determined in advance through experimentation or design in order to determine whether an abnormality has occurred that requires the generator GE to be placed in a power generation uncontrolled state. For example, if the generator rotation speed Nge is not a value corresponding to the engine rotation speed Ne or if the phase representing the rotational position of the rotor of the generator GE does not change, it is determined that an abnormality has occurred. These may occur, for example, due to a malfunction of the generator rotation speed sensor 80.

[0039] When the abnormal condition determination unit 94d determines that an abnormal condition has occurred, the generator control unit 94a places the generator GE in a power generation non-control state, and the electric motor control unit 92c places the electric motor MT in a non-driving state. For example, the generator control unit 94a sets the excitation current Icr to zero. This is to prevent the generated power Wge from becoming abnormally large even when the actual generator rotation speed Nge is high by limiting the magnetic flux from the permanent magnets flowing from the rotor to the stator of the generator GE. This suppresses an increase in the generator temperature THge. In this way, the magnetic flux from the permanent magnets in the generator GE is configured to be smaller than the magnetic flux from the electromagnets formed by the excitation current Icr. By placing the generator GE in a power generation non-control state, damage to the generator GE is minimized. By placing the electric motor MT in a non-driving state, a decrease in the amount of electricity stored in the high-voltage battery 52 is suppressed. When the abnormal condition determination unit 94d determines that an abnormal condition has occurred, the vehicle 10 performs evacuation running using the engine 12 as a power source for running.

[0040] The battery voltage determination unit 94e determines whether the battery voltage Vbat is less than a predetermined voltage determination value Vbat_jdg. The predetermined voltage determination value Vbat_jdg is a predetermined value determined experimentally or by design, which allows temporary evacuation running using the engine even if the battery system is stopped. In other words, when the battery voltage Vbat is equal to or greater than the predetermined voltage determination value Vbat_jdg, power can be supplied from the low-voltage battery 56 to the auxiliary equipment 58.

[0041] The running state determination unit 94f determines whether the vehicle 10 is running, that is, whether the vehicle speed V is not zero.

[0042] When an abnormality occurs and the generator GE is in a power generation non-control state and the vehicle 10 is traveling, the rotation control feasibility determination unit 94g determines whether it is possible to increase the engine rotation speed Ne so that the counter electromotive force Vemf generated by the generator GE is equal to or greater than the battery voltage Vbat. For example, if the counter electromotive force Vemf cannot be increased to equal to or greater than the battery voltage Vbat, or if the counter electromotive force Vemf can be increased to equal to or greater than the battery voltage Vbat but the vehicle acceleration Acc, which is the acceleration of the vehicle 10 in the traveling direction due to the increase in the engine rotation speed Ne, falls outside a predetermined allowable range, it is determined that the engine rotation speed Ne cannot be increased. The predetermined allowable range is a range in which the vehicle acceleration Acc is equal to or less than an acceleration determination value Acc_jdg. The acceleration determination value Acc_jdg is a predetermined determination value determined experimentally or by design, within which the discomfort felt by the driver is within an allowable range. The range equal to or less than the acceleration determination value Acc_jdg corresponds to the "predetermined allowable range" in this invention.

[0043] Fig. 2 is an explanatory diagram of the high-voltage battery 52, inverter 50, generator GE, DC / DC converter 54, and battery system ECU 94 shown in Fig. 1. In Fig. 2, the drive circuit portion of the inverter 50 for the electric motor MT is omitted.

[0044] The inverter 50 includes a rotor coil control circuit 50a and a stator coil control circuit 50b.

[0045] The rotor coil control circuit 50a is a circuit that controls the excitation current Icr of the rotor coil Cr. As described above, the rotor coil control circuit 50a controls the magnitude of the excitation current Icr of the rotor coil Cr by, for example, PWM control. As shown in FIG. 2, for example, the rotor coil control circuit 50a is provided with two pairs of switching elements connected in series between the positive and negative pole lines of the power line pair 60. The switching elements are, for example, insulated gate bipolar transistors (IGBTs) or power MOSFETs. A diode is connected in parallel to each switching element. The connection point between each pair of serially connected switching elements is connected to one terminal and the other terminal of the rotor coil Cr of the generator GE.

[0046] The stator coil control circuit 50b is a circuit that controls the excitation current Ics of the stator coil Cs. As shown in Fig. 2, for example, the stator coil control circuit 50b is provided with three pairs of switching elements connected in series between the positive and negative pole lines of the power line pair 60. A diode is connected in parallel to each switching element. The connection points of each pair of serially connected switching elements are connected to the connection terminals of the U-phase, V-phase, and W-phase of the stator coil Cs of the generator GE, respectively.

[0047] The relay 62 is provided between the high-voltage battery 52 and the pair of power lines 60. That is, the high-voltage battery 52 is connected to the pair of power lines 60 via the relay 62. The pair of power lines 60 has a pair of positive and negative wires. The relay 62 is, for example, a mechanical relay that is switched by the battery system ECU 94 between a closed state (connected state) in which the relay 62 is closed and an open state (disconnected state) in which the relay 62 is opened, and is provided between the positive electrode of the high-voltage battery 52 and the positive wire of the pair of power lines 60, and between the negative electrode of the high-voltage battery 52 and the negative wire of the pair of power lines 60. The relay 62 is a switching device that connects and disconnects the high-voltage battery 52 and the pair of power lines 60.

[0048] A smoothing capacitor C1 is provided between the pair of power lines 60 and near the inverter 50.

[0049] For example, when the battery system ECU 94 turns off all switching elements of the rotor winding control circuit 50a and the stator winding control circuit 50b in the inverter 50, the excitation current Icr becomes zero, and the generator GE is placed in a power generation uncontrolled state. In this case, the engine 12 is put into operation, causing the rotor of the generator GE to rotate in accordance with the engine rotation speed Ne. This generates a rotating magnetic field in which magnetic flux from the permanent magnets rotates, and a back electromotive force Vemf is induced in the stator winding Cs of the generator GE. The back electromotive force Vemf induced in the generator GE is converted into a DC voltage by a diode provided in the inverter 50 and a smoothing capacitor C1 provided between the power line pair 60. The higher the generator rotation speed Nge, i.e., the higher the engine rotation speed Ne, the higher the voltage of the back electromotive force Vemf.

[0050] For example, the generator rotation speed Nge required to generate the back electromotive force Vemf can be calculated by applying the required back electromotive force Vemf to a map in which the relationship between the generator rotation speed Nge and the back electromotive force Vemf is determined experimentally or by design based on the rotating magnetic field of a permanent magnet. The engine rotation speed Ne required to generate the required back electromotive force Vemf is calculated based on this generator rotation speed Nge and a predetermined rotation ratio α.

[0051] Returning to Figure 1, when the abnormal state determination unit 94d determines that an abnormal state has occurred and the battery voltage determination unit 94e determines that the battery voltage Vbat is less than a predetermined voltage determination value Vbat_jdg, the relay control unit 94b controls the relay 62 to an open state, and the converter control unit 94c controls the DC / DC converter 54 to a stopped state.

[0052] When the abnormal state determination unit 94d determines that an abnormal state has occurred, the battery voltage determination unit 94e determines that the battery voltage Vbat is equal to or greater than a predetermined voltage determination value Vbat_jdg, and the running state determination unit 94f determines that the vehicle 10 is not in a running state, the engine control unit 92a increases the engine rotation speed Ne so that the back electromotive force Vemf generated by the generator GE becomes equal to or greater than the battery voltage Vbat, and the converter control unit 94c controls the DC / DC converter 54 to an operating state so that power is supplied from the high-voltage battery 52 to the low-voltage battery 56.

[0053] When the abnormal state determination unit 94d determines that an abnormal state has occurred, the battery voltage determination unit 94e determines that the battery voltage Vbat is equal to or greater than a predetermined voltage determination value Vbat_jdg, and the traveling state determination unit 94f determines that the vehicle 10 is in a traveling state, (a) if the rotation control feasibility determination unit 94g determines that the engine rotation speed Ne can be increased, the engine control unit 92a increases the engine rotation speed Ne as much as possible, and (b) if the rotation control feasibility determination unit 94g determines that the engine rotation speed Ne cannot be increased, the engine control unit 92a controls the engine rotation speed Ne to be based on the required drive torque Trdem. "Increasing the engine rotation speed Ne as much as possible" means as much as possible within a range in which the rotation control feasibility determination unit 94g determines that the engine rotation speed Ne can be increased.

[0054] Fig. 3 is an example of a flowchart illustrating the main control operations of the electronic control device 90 shown in Fig. 1. At the start of the flowchart in Fig. 3, the generator GE is in a power generation amount control state.

[0055] First, in step S10 (hereinafter, "step" will be omitted), which corresponds to the function of the abnormal state determination unit 94d, it is determined whether an abnormal state has occurred that requires the generator GE to be placed in a power generation non-control state. If the determination in S10 is YES, in S20, which corresponds to the functions of the electric motor control unit 92c and the generator control unit 94a, the electric motor MT is placed in a non-driving state and the generator GE is placed in a power generation non-control state. After execution of S20, in S30, which corresponds to the function of the battery voltage determination unit 94e, it is determined whether the battery voltage Vbat is less than a predetermined voltage determination value Vbat_jdg. If the determination in S30 is YES, in step S40, which corresponds to the functions of the relay control unit 94b and the converter control unit 94c, the relay 62 is controlled to an open state and the DC / DC converter 54 is controlled to a stopped state. After execution of S40, in S50, which corresponds to the functions of the engine control unit 92a and the transmission control unit 92b, evacuation traveling using the engine is temporarily performed until just before the auxiliary battery dies. The "dead auxiliary battery" refers to a state in which the auxiliary 58 is unable to operate normally because the power necessary for the auxiliary 58 to operate normally is not supplied. After execution of S50, the flow chart ends.

[0056] If the determination in S30 is NO, then in S60, which corresponds to the function of the traveling state determination unit 94f, it is determined whether the vehicle 10 is traveling. If the determination in S60 is NO, then in S70, which corresponds to the functions of the engine control unit 92a and the converter control unit 94c, the engine rotation speed Ne is increased so that the back electromotive force Vemf generated in the generator GE is equal to or greater than the battery voltage Vbat, and the DC / DC converter 54 is controlled to be in an operating state so that power is supplied from the high-voltage battery 52 to the low-voltage battery 56. If the determination in S60 is YES, then in S80, which corresponds to the function of the rotation controllability determination unit 94g, it is determined whether the engine rotation speed Ne can be increased so that the back electromotive force Vemf generated in the generator GE is equal to or greater than the battery voltage Vbat while the vehicle acceleration Acc is within a range equal to or less than the acceleration determination value Acc_jdg. If the determination in S80 is YES, then the vehicle acceleration Acc can be controlled to be within a range equal to or less than the acceleration determination value Acc_jdg. If the determination in S80 is NO, the vehicle acceleration Acc cannot be controlled to be equal to or less than the acceleration determination value Acc_jdg. If the determination in S80 is YES, the engine rotation speed Ne is increased in S90, which corresponds to the function of the engine control unit 92a. If the determination in S10 is NO or if the determination in S80 is NO, the engine rotation speed Ne is controlled to be based on the required drive torque Trdem in S100, which also corresponds to the function of the engine control unit 92a. After execution of S70, S90, and S100, the process returns.

[0057] According to this embodiment, when the generator GE is placed in a power generation non-control state due to the occurrence of an abnormality, an "increase control" is executed to increase the engine rotation speed Ne so that the back electromotive force Vemf generated by the generator GE becomes equal to or greater than the battery voltage Vbat, and power is supplied from the high-voltage battery 52 to the low-voltage battery 56 via the DC / DC converter 54. Even when the generator GE is placed in a power generation non-control state, the increase control is executed so that the back electromotive force Vemf generated by the generator GE becomes equal to or greater than the battery voltage Vbat, and thus the DC / DC converter 54 continues to supply power from the high-voltage battery 52 to the low-voltage battery 56. This suppresses a decrease in the amount of charge stored in the high-voltage battery 52 and the occurrence of a dead auxiliary battery, thereby suppressing a decrease in the mileage of the vehicle 10.

[0058] According to this embodiment, if the generator GE is placed in the power generation non-control state due to the occurrence of an abnormality and the vehicle is stopped, the increase control is executed. When the vehicle is stopped, an increase in the engine speed Ne does not cause acceleration unintended by the driver. This prevents the vehicle acceleration Acc from becoming unnatural to the driver and suppresses a decrease in the travel distance of the vehicle 10.

[0059] According to this embodiment, when the generator GE is placed in the power generation non-control state due to the occurrence of an abnormal state and the vehicle 10 is in a traveling state, if the vehicle acceleration Acc can be controlled to be equal to or less than the acceleration determination value Acc_jdg, an increase control is executed. If the vehicle acceleration Acc can be controlled to be equal to or less than the acceleration determination value Acc_jdg, the vehicle acceleration Acc is limited to be equal to or less than the acceleration determination value Acc_jdg even if the engine rotation speed Ne increases in the traveling state. This reduces the discomfort felt by the driver and also reduces a decrease in the travel distance of the vehicle 10.

[0060] According to this embodiment, when the generator GE is put into the power generation non-control state due to the occurrence of an abnormal state and the vehicle 10 is in a traveling state, if the vehicle acceleration Acc cannot be controlled to be equal to or less than the acceleration determination value Acc_jdg, the engine rotation speed Ne is determined based on the required drive torque Trdem. If the vehicle acceleration Acc cannot be controlled to be equal to or less than the acceleration determination value Acc_jdg, the engine rotation speed Ne is determined based on the required drive torque Trdem, thereby preventing acceleration unintended by the driver. This prevents the driver from feeling uncomfortable due to the vehicle acceleration Acc.

[0061] According to this embodiment, the vehicle 10 is equipped with an electric motor MT, which is a power source for traveling and is driven by electric power supplied from the high-voltage battery 52. ​​When an abnormal state occurs and the generator GE is put into a power generation non-control state, the electric motor MT is put into a non-driven state. Putting the electric motor MT into a non-driven state suppresses a decrease in the amount of electricity stored in the high-voltage battery 52, and therefore the DC / DC converter 54 is more likely to continue supplying electric power from the high-voltage battery 52 to the low-voltage battery 56 and the auxiliary equipment 58, thereby suppressing the occurrence of a dead auxiliary equipment battery.

[0062] The above-described embodiments of the present invention are merely examples, and the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

[0063] In the above-described embodiment, if the generator GE is placed in the power generation non-control state due to the occurrence of an abnormality and the vehicle is stopped, the augmentation control is executed, but the augmentation control may not be executed. For example, by executing the augmentation control when the vehicle 10 is traveling, the decrease in the amount of stored electricity in the high-voltage battery 52 is suppressed, and the occurrence of the auxiliary battery being dead is suppressed, so that the decrease in the mileage of the vehicle 10 is suppressed.

[0064] In the above-described embodiment, when the generator GE is placed in the power generation non-control state due to the occurrence of an abnormal state and the vehicle 10 is in a traveling state, the augmentation control is executed if the vehicle acceleration Acc can be controlled to be equal to or less than the acceleration determination value Acc_jdg. However, the augmentation control may not be executed. For example, by executing the augmentation control when the vehicle is stopped, the decrease in the amount of charge stored in the high-voltage battery 52 is suppressed, and the occurrence of a dead auxiliary battery is suppressed, thereby suppressing a decrease in the mileage of the vehicle 10.

[0065] In the above-described embodiment, when the generator GE is placed in the power generation non-control state due to the occurrence of an abnormal state and the vehicle 10 is in a traveling state, the engine rotation speed Ne is determined based on the required drive torque Trdem when the vehicle acceleration Acc cannot be controlled to be equal to or less than the acceleration determination value Acc_jdg. However, other embodiments are also possible. For example, an increase control may be executed even in such an uncontrollable state. By executing the increase control, a decrease in the travel distance of the vehicle 10 is suppressed.

[0066] In the above-described embodiment, when the generator GE is put into the power generation non-control state due to the occurrence of an abnormal state, the electric motor MT is put into the non-driving state, but for example, the electric motor MT may be put into the driving state. Even when the electric motor MT is put into the driving state, when the augmentation control is executed, the decrease in the drivable distance of the vehicle 10 is suppressed compared to when the augmentation control is not executed.

[0067] In the above-described embodiment, the rotor of the generator GE is provided with a permanent magnet, but the rotor may not be provided with a permanent magnet. For example, the rotor may not be provided with a permanent magnet, and only a rotor coil Cr may be provided. In such an embodiment, the excitation current Icr may be adjusted to a predetermined constant value (>0) regardless of the generator rotation speed Nge so that, in the event of an abnormality, the magnetic flux from the rotor of the generator GE to the stator becomes approximately the same as that caused by the permanent magnet in the above-described embodiment. The predetermined constant value is a current value determined in advance through experimentation or design so as to minimize damage to the generator GE.

[0068] In the above-described embodiment, the belt transmission device 40 connects the engine 12, the generator GE, and the air compressor AC to one another. However, for example, the belt transmission device 40 may connect the engine 12 and the generator GE to one another but not the air compressor AC.

[0069] In the above-described embodiment, the "control device" of the present invention is configured to be divided into the drive system ECU 92 and the battery system ECU 94, but the present invention is not limited to this. For example, the "control device" may be further divided into functions as needed than in the above-described embodiment, or all functions may be combined into one. [Explanation of symbols]

[0070] 10: Vehicle, 12: Engine, 52: High-voltage battery, 54: DC / DC converter, 56: Low-voltage battery, 58: Auxiliary equipment, 90: Electronic control unit (control unit), Acc: Vehicle acceleration, MT: Electric motor, GE: Generator, Ne: Engine rotation speed (engine rotation speed), Trdem: Required driving torque, Vbat: Battery voltage (high-voltage battery voltage), Vemf: Back electromotive force

Claims

1. A control device for a vehicle including an engine, a generator connected to the engine, a high-voltage battery capable of supplying and receiving electric power to and from the generator, a low-voltage battery having a lower voltage than the high-voltage battery and supplying electric power to an auxiliary device that drives the engine, and a DC / DC converter provided between the high-voltage battery and the low-voltage battery, When the generator is placed in a power generation non-control state due to the occurrence of an abnormal state, an increase control is executed to increase the rotation speed of the engine so that the counter electromotive force generated by the generator becomes equal to or greater than the voltage of the high voltage battery, and power is supplied from the high voltage battery to the low voltage battery via the DC / DC converter. A vehicle control device characterized by:

2. When the generator is in a power generation non-control state due to the occurrence of the abnormal state and the vehicle is stopped, the increase control is executed.

2. The vehicle control device according to claim 1.

3. When the generator is placed in a power generation non-control state due to the occurrence of the abnormal state, if the vehicle is in a traveling state and the vehicle acceleration can be controlled within a predetermined allowable range, the increase control is executed.

2. The vehicle control device according to claim 1.

4. When the generator is in the power generation non-control state due to the occurrence of the abnormal state, if the vehicle is in the traveling state and the vehicle acceleration cannot be controlled within a predetermined allowable range, the rotation speed of the engine is determined based on the required drive torque.

4. The vehicle control device according to claim 3.

5. The vehicle further includes an electric motor as a power source for traveling that is driven by electric power supplied from the high-voltage battery, When the generator is put into a power generation non-control state due to the occurrence of the abnormal state, the electric motor is put into a non-driving state.

5. A vehicle control device according to claim 1.

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