JP6432534B2 - Hybrid vehicle - Google Patents

Description

  The present invention relates to a hybrid vehicle.

  The hybrid vehicle includes an engine and a motor generator that is driven by electric power supplied from a battery as a drive source, and travels by the power of at least one of the engine or the motor generator.

  As a conventional hybrid vehicle, one described in Patent Document 1 is known. In the hybrid vehicle described in Patent Document 1, a lead battery and a lithium ion battery are connected in parallel to the generator, and the conduction state between these batteries is switched and the generated voltage of the generator is adjusted. Thus, the power supply to the electric load can be suitably performed.

JP 2014-033571 A

  Here, in a hybrid vehicle capable of EV traveling, in an EV state in which EV traveling is possible (EV traveling mode), the engine is stopped, and in addition to not consuming fuel, engine noise is generated. Therefore, comfort, quietness and fuel efficiency can be improved. For this reason, it is desirable to extend the time for executing the EV traveling mode. In order to execute the EV traveling mode, it is necessary that the state of charge of the battery that supplies power to the vehicle system is good.

  However, the hybrid vehicle described in Patent Document 1 does not consider maintaining EV travel longer. For this reason, there existed a problem that the residence time of EV driving mode could not be extended or a fuel consumption could not be improved.

  The present invention electrically disconnects two batteries installed for supplying electric power to an electric load during the EV traveling mode, and prevents the flow of electricity from a battery having a high voltage to a battery having a low voltage. The purpose is to extend the mode stay time and improve fuel economy.

One aspect of the invention of a hybrid vehicle that solves the above-described problems is a hybrid vehicle that includes an engine and a motor generator as drive sources, and that travels by power output from at least one of the engine and the motor generator. different from the first battery and the second battery, two first connection state in which the relative electric load the first battery and the second battery are connected in parallel, the first battery to one of said electric load And a connection switch that forms any one of a second connection state in which the parallel connection is disconnected so that the second battery is connected to the other of the electrical loads, and the connection switch A connection switch control unit that controls a connection state of the motor generator. During implementation of the travelable EV drive mode by the power that is characterized by the connection switch to the second connection state.

  According to the present invention, the staying time in the EV traveling mode can be extended and the fuel consumption can be improved.

FIG. 1 is a diagram illustrating a hybrid vehicle according to an embodiment of the present invention, and is a configuration diagram of the hybrid vehicle. FIG. 2 is a diagram illustrating a hybrid vehicle according to an embodiment of the present invention, and is a configuration diagram of a low-voltage system of the hybrid vehicle. FIG. 3 is a flowchart showing the flow of the switch switching operation by the hybrid vehicle according to the embodiment of the present invention. FIG. 4 is a timing chart when the switch switching operation is executed in the hybrid vehicle according to the embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings. Hereinafter, a vehicle equipped with a drive control device according to an embodiment of the present invention will be described.

  As shown in FIG. 1, the hybrid vehicle 1 includes an engine 2 as an internal combustion engine, a transmission 3, a motor generator 4, drive wheels 5, and an HCU (Hybrid Control Unit) that comprehensively controls the hybrid vehicle 1. 10, an ECM (Engine Control Module) 11 that controls the engine 2, a TCM (Transmission Control Module) 12 that controls the transmission 3, an ISGCM (Integrated Starter Generator Control Module) 13, and an INVCM (Invertor Control Module) 14 And a low voltage BMS (Battery Management System) 15 and a high voltage BMS 16.

  The engine 2 is formed with a plurality of cylinders. In the present embodiment, the engine 2 is configured to perform a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke for each cylinder.

  The engine 2 is connected with an ISG (Integrated Starter Generator) 20 and a starter 21. The ISG 20 is connected to the crankshaft 18 of the engine 2 via a belt 22 or the like. The ISG 20 has a function of an electric motor that starts the engine 2 by rotating when supplied with electric power, and a function of a generator that converts rotational force input from the crankshaft 18 into electric power.

  In this embodiment, the ISG 20 is configured to restart the engine 2 from a stopped state by the idling stop function by functioning as an electric motor under the control of the ISGCM 13. The ISG 20 can also assist the traveling of the hybrid vehicle 1 by functioning as an electric motor.

  The starter 21 includes a motor and a pinion gear (not shown). The starter 21 rotates the crankshaft 18 by rotating the motor to give the engine 2 a starting torque. As described above, the engine 2 is started by the starter 21 and restarted by the ISG 20 from the stop state by the idling stop function.

  The transmission 3 shifts the rotation output from the engine 2 and drives the drive wheels 5 via the drive shaft 23. The transmission 3 includes an always-meshing transmission mechanism 25 including a parallel shaft gear mechanism, a clutch 26 including a dry single-plate clutch, a differential mechanism 27, a clutch actuator 51, and a shift actuator 52. Yes.

  The clutch actuator 51 is configured to connect and disconnect (disconnect and connect) the clutch 26 under the control of the TCM 12. The shift actuator 52 switches a gear position by moving a shift sleeve (not shown) of the transmission mechanism 25 under the control of the TCM 12. Hereinafter, switching the gear stage by disengaging the clutch 26 is also simply referred to as shifting.

  As described above, the transmission 3 is configured as an automatic transmission called AMT (Automated Manual Transmission) that can automatically shift gears under the control of the TCM 12. The differential mechanism 27 is configured to transmit the power output by the speed change mechanism 25 to the drive shaft 23.

  The motor generator 4 is connected to the differential mechanism 27 via a power transmission mechanism 28 such as a chain. The motor generator 4 functions as an electric motor.

  Thus, the hybrid vehicle 1 forms a parallel hybrid system that can use the power of both the engine 2 and the motor generator 4 for driving the vehicle. The hybrid vehicle 1 travels with power generated by at least one of the engine 2 and the motor generator 4.

  The hybrid vehicle 1 assists the engine torque of the engine 2 by using only the engine torque generated by the engine 2, traveling only by the motor torque generated by the motor generator 4 (EV traveling), and using the motor torque as an assist torque. Travel (assist travel) is possible. Thus, the hybrid vehicle 1 has an EV travel function and an assist travel function.

  The motor generator 4 also functions as a generator and generates power when the hybrid vehicle 1 travels. The motor generator 4 may be connected to any part of the power transmission path from the transmission 3 to the drive wheel 5 so as to be able to transmit power, and is not necessarily connected to the differential mechanism 27.

  The hybrid vehicle 1 includes a first power storage device 30, a low voltage power pack 32 including a second power storage device 31, a high voltage power pack 34 including a third power storage device 33, a high voltage cable 35, and a low voltage cable 36. And.

  The 1st electrical storage apparatus 30, the 2nd electrical storage apparatus 31, and the 3rd electrical storage apparatus 33 are comprised from the rechargeable secondary battery. First power storage device 30 is formed of a lead battery. The second power storage device 31 is a power storage device with higher output and higher energy density than the first power storage device 30.

  The second power storage device 31 can be charged in a shorter time than the first power storage device 30. In this embodiment, the 2nd electrical storage apparatus 31 consists of a lithium ion battery. The second power storage device 31 may be a nickel hydride storage battery.

  The first power storage device 30 and the second power storage device 31 are low-voltage batteries in which the number of cells is set so as to generate an output voltage of about 12V. The 3rd electrical storage apparatus 33 consists of a nickel hydride storage battery or a lithium ion battery, for example.

  The third power storage device 33 is a high voltage battery in which the number of cells is set so as to generate a higher voltage than the first power storage device 30 and the second power storage device 31, and generates an output voltage of 100V, for example. The state such as the remaining capacity of the third power storage device 33 is managed by the high voltage BMS 16.

  The hybrid vehicle 1 is provided with a general load 37 and a protected load 38 as two types of electric loads. The general load 37 and the protected load 38 are electric loads other than the starter 21 and the ISG 20.

  The protected load 38 is an electric load that always requires a stable power supply. The protected load 38 includes a stability control device 38A that prevents a side slip of the vehicle, an electric power steering control device 38B that electrically assists the operating force of the steering wheel, and a headlight 38C. The protected load 38 also includes instrument panel lamps and meters (not shown) and a car navigation system.

  The general load 37 is an electric load that is temporarily used without requiring stable power supply as compared with the protected load 38. The general load 37 includes, for example, a wiper (not shown) and an electric cooling fan that blows cooling air to the engine 2.

  The low voltage power pack 32 includes switches 40 and 41 and a low voltage BMS 15 in addition to the second power storage device 31. The first power storage device 30 and the second power storage device 31 are connected to the starter 21, the ISG 20, the general load 37 as an electrical load, and the protected load 38 via a low voltage cable 36 so as to be able to supply power. Yes. The first power storage device 30 and the second power storage device 31 are electrically connected in parallel to the protected load 38.

  The switch 40 is provided in the low voltage cable 36 between the second power storage device 31 and the protected load 38. The switch 41 is provided in the low voltage cable 36 between the first power storage device 30 and the protected load 38.

  The low voltage BMS 15 controls charging / discharging of the second power storage device 31 and power supply to the protected load 38 by controlling opening and closing of the switches 40 and 41. When the engine 2 is stopped due to idling stop, the low voltage BMS 15 closes the switch 40 and opens the switch 41, thereby supplying power from the second power storage device 31 having high output and high energy density to the protected load 38. It comes to supply.

  When the engine 2 is started by the starter 21 and when the engine 2 stopped by the idling stop control is restarted by the ISG 20, the low voltage BMS 15 opens the switch 41 and opens the switch 41. Electric power is supplied from the power storage device 30 to the starter 21 or the ISG 20. When the switch 40 is closed and the switch 41 is opened, power is also supplied from the first power storage device 30 to the general load 37.

  As described above, the first power storage device 30 supplies at least electric power to the starter 21 and the ISG 20 as starters for starting the engine 2. The second power storage device 31 supplies at least power to the general load 37 and the protected load 38.

  The second power storage device 31 is connected so as to be able to supply power to both the general load 37 and the protected load 38. However, the second power storage device 31 preferentially supplies power to the protected load 38 for which stable power supply is always required. Thus, the switches 40 and 41 are controlled by the low voltage BMS 15.

  The low voltage BMS 15 is charged to the first power storage device 30 and the second power storage device 31 (also referred to as SOC: State Of Charge, power storage state, remaining charge amount, charge capacity), and to the general load 37 and the protected load 38. The switches 40 and 41 may be controlled differently from the above-mentioned example in consideration of the operation requirements of the above, giving priority to stable operation of the protected load 38.

  The high voltage power pack 34 includes an inverter 45, INVCM 14, and high voltage BMS 16 in addition to the third power storage device 33. The high voltage power pack 34 is connected to the motor generator 4 via a high voltage cable 35 so that electric power can be supplied.

  The inverter 45 is configured to mutually convert AC power applied to the high voltage cable 35 and DC power applied to the third power storage device 33 under the control of the INVCM 14. For example, when powering the motor generator 4, the INVCM 14 converts the DC power discharged by the third power storage device 33 into AC power by the inverter 45 and supplies the AC power to the motor generator 4.

  When the motor generator 4 is regenerated, the INVCM 14 converts the AC power generated by the motor generator 4 into DC power by the inverter 45 and charges the third power storage device 33.

  HCU10, ECM11, TCM12, ISGCM13, INVCM14, low voltage BMS15 and high voltage BMS16 are respectively CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), backup data, etc. Is constituted by a computer unit having a flash memory for storing, an input port, and an output port.

  The ROMs of these computer units store various constants and maps, and programs for causing the computer units to function as the HCU 10, ECM 11, TCM 12, ISGCM 13, INVCM 14, low voltage BMS 15 and high voltage BMS 16, respectively. Yes.

  That is, when the CPU executes a program stored in the ROM using the RAM as a work area, these computer units are referred to as the HCU 10, ECM 11, TCM 12, ISGCM 13, INVCM 14, low voltage BMS 15, and high voltage BMS 16 in this embodiment. Each functions.

  In the present embodiment, the ECM 11 performs idling stop control. In this idling stop control, the ECM 11 stops the engine 2 when a predetermined stop condition is satisfied, and restarts the engine 2 by driving the ISG 20 via the ISGCM 13 when the predetermined restart condition is satisfied. . For this reason, unnecessary idling of the engine 2 is not performed, and the fuel efficiency of the hybrid vehicle 1 can be improved.

  In the present embodiment, the ECM 11 stops the engine 2 with a predetermined stop condition that the vehicle is in a stopped state (the vehicle speed is zero). Thus, the hybrid vehicle 1 is provided with a stop IS (Idling Stop) function that performs idling stop when the vehicle stops. When the vehicle is stopped by the idling stop on the uphill road where the road surface state is inclined, the electric motor function of the motor generator 4 is used to maintain the stopped state of the vehicle. Maintenance of the stop state of the vehicle by the motor generator 4 is performed using the electric power of the third power storage device 33.

  The hybrid vehicle 1 is provided with CAN communication lines 48 and 49 for forming an in-vehicle LAN (Local Area Network) conforming to a standard such as CAN (Controller Area Network).

  The HCU 10 is connected to the INVCM 14 and the high voltage BMS 16 by a CAN communication line 48. The HCU 10, INVCM 14 and high voltage BMS 16 mutually transmit and receive signals such as control signals via the CAN communication line 48.

  The HCU 10 is connected to the ECM 11, the TCM 12, the ISGCM 13 and the low voltage BMS 15 by a CAN communication line 49. The HCU 10, ECM 11, TCM 12, ISGCM 13, and low voltage BMS 15 mutually transmit and receive signals such as control signals via the CAN communication line 49.

  The hybrid vehicle 1 of this embodiment has a gap filling function. The gap filling function is a function of driving the motor generator 4 during the shift of the transmission 3 and applying the torque of the motor generator 4 to the drive wheels 5.

  The HCU 10 implements the gap filling function by executing the gap filling control operation when the operation is permitted. While the transmission 3 is shifting, the clutch 26 is disengaged and engine torque cannot be transmitted from the engine 2 to the drive wheels 5. For this reason, the HCU 10 applies the motor torque (assist torque) generated by the power running operation of the motor generator 4 to the drive wheels 5 in the gap filling control operation. By this gap filling function, the feeling of deceleration due to the disengagement of the clutch 26 during the shift is suppressed, and the running performance of the vehicle can be improved.

  In FIG. 2, the hybrid vehicle 1 includes a first charging state detection unit 61, which detects the charging state of the first power storage device 30 and outputs a detection signal to the HCU 10. . The first charge state detection unit 61 is provided in the vicinity of the first power storage device 30, and detects the voltage between the terminals of the first power storage device 30 and the input / output current to the first power storage device 30, thereby The state of charge of power storage device 30 is detected.

  The hybrid vehicle 1 also includes a second charge state detection unit 62, which detects the charge state of the second power storage device 31 and outputs a detection signal to the HCU 10. The second charge state detection unit 62 is provided in the vicinity of the second power storage device 31, and detects the voltage between the terminals of the second power storage device 31 and the input / output current to the second power storage device 31, thereby The state of charge of the power storage device 31 is detected. The second charge state detection unit 62 outputs a detection signal to the HCU 10 via the low voltage BMS 15.

  The low voltage cable 36 is branched into two between the first power storage device 30 and the second power storage device 31. One of the branch portions of the low voltage cable 36 is provided with the switch 41 and the fuse described above. A switch 42 and a fuse are provided on the other branch of the low voltage cable 36. Here, as described later, the open / close states of the switch 41 and the switch 42 are controlled to be equal to each other. For example, when the switch 41 is closed, the switch 42 is also closed. For this reason, the switch 42 is omitted in FIG.

  The general load 37 includes, for example, a blower fan, a radiator fan, an electric water pump, an electric negative pressure pump, an indoor lamp, and the like in addition to the wiper and the electric cooling fan described above.

  The protected load 38 includes, in addition to the above-described stability control device 38A, electric power steering control device 38B, and headlight 38C, navigation (car navigation system), audio, meter, air conditioning panel, steering angle sensor, stereo camera, etc. Is included.

  Here, the first connection state is formed when all of the switches 40, 41, and 42 described above are in the connected state (closed state). This first connection state is a state in which the first power storage device 30 and the second power storage device 31 are connected in parallel to the general load 37 and the protected load 38 that are electrical loads.

  Further, among the switches 40, 41, and 42, when the switch 40 is in the connected state (closed state) and the switches 41 and 42 are in the disconnected state (open state), the second connected state is formed. In this second connection state, the first power storage device 30 is connected to one general load 37 of the electric load, and the second power storage device 31 is connected to the other protected load 38 of the electric load. State.

  In this second connection state, since the switches 41 and 42 are in a disconnected state (open state), the parallel connection between the second power storage device 30 and the second power storage device 31 is disconnected. The switches 40, 41, and 42 constitute a connection switch in the present invention. Moreover, the 1st electrical storage apparatus 30 comprises the 1st battery in this invention, and the 2nd electrical storage apparatus 31 comprises the 2nd battery in this invention.

  Here, the difference in battery characteristics between the first power storage device 30 made of a lead battery and the second power storage device 31 made of a lithium ion battery will be described in detail.

  There are the following characteristic differences between the first power storage device 30 and the second power storage device 31.

  Regarding the battery voltage at the time of full charge, there is a difference in characteristics that the second power storage device 31 made of a lithium ion battery is lower than the first power storage device 30 made of a lead battery.

  Regarding the internal resistance of the battery, there is a difference in characteristics that the second power storage device 31 made of a lithium ion battery is lower than the first power storage device 30 made of a lead battery.

  For this reason, regarding the time required for full charge, the second power storage device 31 made of a lithium ion battery is shorter (faster) than the first power storage device 30 made of a lead battery.

  Therefore, when charging starts simultaneously with the first power storage device 30 and the second power storage device 31 connected in parallel to the ISG 20, the second power storage device 31 is fully charged before the first power storage device 30. become.

  Moreover, since the voltage of a single cell of a lithium ion battery is 2.3V (lower limit voltage 1.5V, upper limit voltage 3.3V), the voltage in the case of a 4-cell assembled battery is 9.2V, The 12V power supply voltage range (6V to 14V) is the closest. Moreover, when it is set as a 4 cell assembled battery, an upper voltage and a minimum voltage will be 13.5V and 9.2V, respectively. As described above, the first power storage device 30 and the second power storage device 31 have different characteristics such as a voltage when fully charged.

  On the other hand, since the engine 2 is stopped and the ISG 20 cannot generate power during the EV travel mode, the first power storage device 30 and the second power storage device 31 supply power to the general load 37 and the protected load 38. Need to bear.

  For this reason, in order to implement EV drive mode, the charge condition of the 1st electrical storage apparatus 30 and the 2nd electrical storage apparatus 31 needs to be favorable.

  As described above, since the first power storage device 30 and the second power storage device 31 have different characteristics, the charging state in which the EV travel mode is permitted is set to a different value between the first power storage device 30 and the second power storage device 31. ing.

  In the present embodiment, the HCU 10 includes a connection switch control unit 10A, and the connection switch control unit 10A controls the connection state of the switches 40, 41, and 42.

  Then, the connection switch control unit 10 </ b> A sets the switches 40, 41, and 42 to the second connection state during the execution of the EV traveling mode in which the traveling by the power output from the motor generator 4 is possible.

  Note that the actual switching of the switches 40, 41, and 42 is performed by the low voltage BMS 15 in response to a switching request from the connection switch control unit 10A of the HCU 10 to the low voltage BMS 15. Further, the connection switch control unit 10A may be provided in the ECM 30 instead of the HCU 10.

  The switch switching operation executed in the hybrid vehicle configured as described above will be described with reference to the flowchart shown in FIG. In this switch switching operation, the switch 40 is always in a connected state (closed state), and the switches 41 and 42 are switched.

  In FIG. 3, the HCU 10 determines whether or not the engine 2 is automatically stopped by performing the EV travel mode (step S <b> 1).

  When it is determined in step S1 that the engine 2 is not automatically stopped, the HCU 10 ends the routine of one time in the flowchart of FIG.

  When it is determined in step S1 that the engine 2 is automatically stopped, the HCU 10 determines that the voltage of the first power storage device 30 (indicated as a lead battery in the drawing) is the second power storage device 31 (in the drawing as a lithium ion battery). It is determined whether or not the voltage is higher than the voltage (step S2).

  When it is determined in step S2 that the voltage of the first power storage device 30 is higher than the voltage of the second power storage device 31, the HCU 10 opens the switches 41 and 42 (denoted as connection switches in the drawing) and the first power storage device 30 The second power storage device 31 is shut off (step S3).

  As described above, during the execution of the EV traveling mode, the first power storage device 30 and the second power storage device 31 are discharged to the general load 37 and the protected load 38. The second power storage device 31 is electrically disconnected. This prevents electricity from flowing from the first power storage device 30 to the second power storage device 31. For this reason, since it can prevent that the charge condition of the 1st electrical storage apparatus 30 falls and EV driving mode is prohibited, EV driving mode can be maintained longer.

  On the other hand, if it is determined in step S2 that the voltage of the first power storage device 30 is not higher than the voltage of the second power storage device 31, the HCU 10 determines that the voltages of the first power storage device 30 and the second power storage device 31 are in the EV travel mode. It is determined whether or not the voltage is greater than or equal to an executable voltage (step S4).

  When it is determined in step S4 that the voltage is higher than the voltage at which the EV driving mode can be performed, the HCU 10 determines whether or not the engine 2 needs to be started for driving the air conditioner or for depressing the accelerator pedal. (Step S5).

  When it is determined in step S5 that the engine 2 needs to be restarted, the HCU 10 restarts the engine 2 (step S6).

  When it is determined in step S5 that the restart of the engine 2 is not necessary, the HCU 10 ends the routine of one time in the flowchart of FIG.

  After step S6, the HCU 10 closes the switches 41 and 42 (connected state) to electrically connect the first power storage device 30 and the second power storage device 31 (step S7). End the routine.

  On the other hand, when it is determined in step S4 that the voltage is not higher than the voltage at which the EV traveling mode can be performed, the HCU 10 restarts the engine 2 (step S8).

  After step S8, the HCU 10 closes the switches 41 and 42 (connected state) to electrically connect the first power storage device 30 and the second power storage device 31 (step S9). End the routine.

  Thus, in a state where charging from the ISG 20 to the first power storage device 30 and the second power storage device 31 is possible by restarting the engine 2, the first power storage device 30 with respect to the ISG 20 is performed by performing step S 7 or step S 9. And the second power storage device 31 are connected in parallel. Thereby, both the 1st electrical storage apparatus 30 and the 2nd electrical storage apparatus 31 can be charged.

  FIG. 4 shows a timing chart when the switch switching operation of FIG. 3 is executed. In FIG. 4, during a period before time t1, the engine 2 is operating, and the switches 41 and 42 (referred to as changeover switches in the figure) are in a closed state (connected state). Then, the ISG 20 performs a power generation operation using the engine 2 as a power source, and the ISG 20 charges both the first power storage device 30 (referred to as a lead battery in the figure) and the second power storage device 31 (referred to as a Li battery in the figure). Has been done.

  In response to the fact that the voltage of the second power storage device 31 made of a lithium ion battery has reached the full charge voltage before the time t1, the switches 41 and 42 are opened (cut off) at the time t1. Thus, since second power storage device 31 is electrically disconnected from ISG 20, charging to second power storage device 31 is stopped and charging to first power storage device 30 is continued.

  Thereafter, engine 2 is stopped at time t2 in response to the voltage of first power storage device 30 made of a lead battery reaching a fully charged voltage. Thereby, the charge to the 1st electrical storage apparatus 30 is stopped. Further, the EV travel mode is performed at time t2.

  After time t2, the voltage of the first power storage device 30 and the voltage of the second power storage device 31 continue to decrease gradually. Then, the voltage of the first power storage device 30 becomes less than the full charge voltage of the second power storage device 31 at time t3, and the voltage of the second power storage device 31 becomes less than the lower limit voltage threshold of the second power storage device 31 at time t4.

  Between time t2 and time t3, in order to charge the first power storage device 30 in response to the charge request while preventing overcharging of the second power storage device 31, even if the engine 2 is restarted and power generation is started, The switch 41 is maintained in the open state (disconnected state). During this period, the switch 41 is maintained in the open state, so that only the first power storage device 30 is charged from the ISG 20.

  Between time t3 and time t4, when the engine 2 is restarted due to a factor other than the charging request such as driving of the air conditioner or depression of the accelerator pedal, the switch 41 is closed (connected state) after the engine 2 is restarted. To be. During this period, the switch 41 is closed (connected state), so that the ISG 20 charges both the first power storage device 30 and the second power storage device 31.

  After time t4, in order to prevent the first power storage device 30 or the second power storage device 31 from being overdischarged, the voltage of the first power storage device 30 or the second power storage device 31 is less than the lower limit voltage threshold. In order to charge the battery, the engine 2 is restarted and the switch 41 is closed (connected state). During this period, the switch 41 is closed (connected state), so that the ISG 20 charges both the first power storage device 30 and the second power storage device 31.

  The effects of the hybrid vehicle according to the present embodiment described above will be described. The hybrid vehicle 1 of the present embodiment includes a first power storage device 30 and a second power storage device 31 having different characteristics.

  The hybrid vehicle 1 includes a first connection state in which the first power storage device 30 and the second power storage device 31 are connected in parallel to the general load 37 and the protected load 38, and the first power storage device to the general load 37. 30, and the switches 40, 41, 42 that form any one of the second connection states in which the parallel connection is disconnected so that the second power storage device 31 is connected to the protected load 38. Is provided.

  Further, the hybrid vehicle 1 includes a connection switch control unit 10A that controls the connection state of the connection switch.

  Then, the connection switch control unit 10 </ b> A sets the switches 40, 41, and 42 to the second connection state during the execution of the EV traveling mode in which the traveling by the power output from the motor generator 4 is possible.

  With this configuration, during the EV travel mode, the switches 40, 41, 42 are set in the second connection state, thereby disconnecting the connection between the first power storage device 30 and the second power storage device 31. Power can be supplied to the load.

  For this reason, electricity can be prevented from flowing from the first power storage device 30 to the second power storage device 31. Thereby, it can prevent that one of the 1st electrical storage apparatus 30 and the 2nd electrical storage apparatus 31 falls to a minimum voltage, and does not satisfy | fill the implementation conditions of EV driving mode. As a result, the EV traveling mode can be continued for a long time. As a result, the staying time in the EV traveling mode can be extended and the fuel consumption can be improved.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 2 Engine 4 Motor generator 10A Connection switch control part 30 1st electrical storage apparatus (1st battery)
31 Second power storage device (second battery)
37 General load (Electrical load or Electric load)
38 Protected load (electric load, the other of electric load)
40, 41, 42 switch (connection switch)

Claims (1)

A hybrid vehicle that includes an engine and a motor generator as drive sources, and that travels by power output from at least one of the engine and the motor generator,
A first battery and a second battery having different characteristics;
A first connection state in which the first battery and the second battery are connected in parallel to two types of electric loads; the first battery is connected to one of the electric loads; and A connection switch that forms any one of a second connection state in which the parallel connection is disconnected so that the second battery is connected to the other;
A connection switch control unit for controlling a connection state of the connection switch,
The hybrid switch according to claim 1, wherein the connection switch control unit sets the connection switch to a second connection state during execution of an EV traveling mode in which the vehicle can travel with power output from the motor generator.

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