JP2014072913A - Vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle capable of preventing waste of electric energy.SOLUTION: In a vehicle, a power-generating engine 12 is driven with an amount of power stored in a driving battery 5 being a prescribed value or greater, and when a power generator 13 generates power, an output voltage of a DC/DC converter 15 is raised from a normal output voltage to a high output voltage. Thereby, a voltage of electric energy generated in the power generator 13 is converted into the high output voltage by the DC/DC converter 15 and supplied to a battery 14 for an auxiliary. Before an output voltage of the DC/DC converter 15 is raised to a high output voltage, a terminal voltage of the driving battery 5 is equal to a normal output voltage or less. Accordingly, when the high output voltage is supplied to the battery 14 for an auxiliary from the DC/DC converter 15, the battery 14 for an auxiliary is charged until a terminal voltage of the battery 14 for the auxiliary reaches the high output voltage.

Description

The present invention relates to a range extended electric vehicle (REEV).
Electric vehicle and plug-in hybrid (PHV)
Vehicle).

  Vehicles such as range-extended electric vehicles and plug-in hybrid cars are equipped with a motor, an engine, a generator, and a driving battery.

  The motor is driven by the electric power stored in the driving battery. The output of the motor is transmitted to the driving wheel as a driving force for traveling, and rotates the driving wheel. Thereby, the vehicle travels. When the vehicle decelerates, the power of the drive wheels is regenerated into electric power by the motor. Further, when the remaining capacity of the driving battery decreases, the engine is driven. Then, the driving force of the engine is transmitted to the generator, and electric power is generated by the generator. The electric power generated by the motor and the generator is supplied to the drive battery and stored in the drive battery.

  Since this type of vehicle is equipped with an engine, engine exhaust heat (cooling water) is used as a heat source for the air conditioner. Therefore, when the vehicle interior needs to be heated, the engine is driven and the heater core of the air conditioner is heated by the engine coolant. Even during the heating, the driving power of the engine can be transmitted to the generator, and the driving battery can be charged by the power generation of the generator.

Japanese Patent Laid-Open No. 9-233601

  However, when the driving battery is fully charged, even if the engine is driven during heating of the vehicle, no current flows from the generator to the driving battery, and the driving battery cannot be charged. Further, when the driving battery is fully charged, the driving battery cannot be charged with regenerative power when the vehicle is decelerated. Therefore, the electric energy that can be stored if the drive battery is empty is wasted.

  An object of the present invention is to provide a vehicle capable of preventing waste of electric energy.

  In order to achieve the above object, a vehicle according to the present invention is driven by power generation means for converting kinetic energy into electrical energy, a drive power storage device that stores electrical energy, and electrical energy stored in the drive power storage device. Drive motor, a voltage converter that converts the voltage of the electric energy input from the drive power storage device into a different voltage, and a voltage that is output by the electric energy of the voltage converted by the voltage converter. When the power generation means generates power in a state where the power storage amount of the power storage device and the drive power storage device is less than a predetermined value, a normal output voltage is output from the voltage conversion device, and the power storage of the drive power storage device When the power generation means generates power in a state where the amount is equal to or greater than a predetermined value, a high output voltage higher than the normal output voltage is output from the voltage converter. Sea urchin, and a control means for controlling the voltage conversion device.

  According to this configuration, when the power generation unit generates power in a state where the amount of power stored in the drive power storage device is less than the predetermined value, the electrical energy generated by the power generation unit can be stored in the drive power storage device. If the auxiliary power storage device is not fully charged, a part of the electric energy generated by the power generation means is converted into a normal output voltage by the voltage conversion device and supplied to the auxiliary power storage device. The As a result, the auxiliary power storage device is charged. When the terminal voltage of the auxiliary power storage device matches the normal output voltage, the auxiliary power storage device is fully charged, and charging of the auxiliary power storage device is completed.

  When the power generation means generates power in a state where the power storage amount of the drive power storage device is equal to or greater than a predetermined value, the output voltage of the voltage conversion device is raised from the normal output voltage to the high output voltage. As a result, the electric energy generated by the power generation means is converted into a high output voltage by the voltage converter and supplied to the auxiliary power storage device. Before the output voltage of the voltage conversion device is raised to a high output voltage, the terminal voltage of the driving power storage device is equal to or lower than the normal output voltage. Therefore, when a high output voltage is supplied from the voltage converter to the auxiliary power storage device, the auxiliary power storage device is charged until the terminal voltage of the auxiliary power storage device rises to the high output voltage.

  Therefore, it is possible to prevent waste of electric energy in a state where the amount of power stored in the driving power storage device is equal to or greater than a predetermined value.

  Further, the electrical energy stored in the power storage device for auxiliary machines exceeding the normal output voltage is consumed as driving power for the auxiliary machines when the power generation means does not generate power. At this time, the auxiliary power storage device is not charged with the electric energy of the drive power storage device until the terminal voltage of the auxiliary power storage device drops to the normal output voltage. Therefore, consumption of electrical energy stored in the drive power storage device can be suppressed, and power consumption is improved.

  The vehicle may further include an engine and an air conditioner that heats the vehicle interior using exhaust heat of the engine. In this case, the power generation means is a generator that converts the driving force of the engine into electric energy, and the control means is for heating by the air conditioner in a state where the amount of power stored in the power storage device for driving is less than a predetermined value. When the engine is driven, a normal output voltage is output from the voltage conversion device, and when the engine is driven for heating by the air conditioner in a state where the storage amount of the driving power storage device is equal to or greater than a predetermined value The voltage converter is preferably controlled so that a high output voltage higher than the normal output voltage is output from the voltage converter.

  Since the engine is driven during the heating operation of the air conditioner, the driving force of the engine can be converted into electric energy by the generator. When the engine is being driven for heating by the air conditioner in a state where the power storage amount of the drive power storage device is equal to or greater than a predetermined value, the output voltage of the voltage conversion device is raised from the normal output voltage to the high output voltage. As a result, during the heating operation of the air conditioner, even when the amount of power stored in the drive power storage device is equal to or greater than a predetermined value, the electrical energy generated by the generator can be stored in the auxiliary power storage device.

  Therefore, it is possible to prevent waste of electric energy during the heating operation of the air conditioner.

  The power generation means may be a drive motor. In this case, the control means outputs a normal output voltage from the voltage conversion device when the power is regenerated to electric energy by the drive motor in a state where the amount of power stored in the drive power storage device is less than a predetermined value, and the drive power storage device When the power stored in the device is greater than or equal to a predetermined value and the power is regenerated to electrical energy by the drive motor, the voltage converter is set so that a high output voltage higher than the normal output voltage is output from the voltage converter. It is preferable to control.

  When power is converted into electric energy by the drive motor in a state where the power storage amount of the drive power storage device is equal to or greater than a predetermined value, the output voltage of the voltage conversion device is raised from the normal output voltage to the high output voltage. Thus, when power is converted into electric energy by the drive motor, that is, when regenerative energy is obtained, the regenerative energy is stored in the auxiliary power storage device even if the power storage amount of the drive power storage device is equal to or greater than a predetermined value. Can be stored.

  Therefore, when the regenerative energy is obtained, that is, when the vehicle is decelerated, the regenerative energy can be prevented from being wasted.

  According to the present invention, even when the amount of power stored in the drive power storage device is equal to or greater than a predetermined value, the electrical energy obtained at that time can be stored in the auxiliary power storage device. Therefore, waste of electric energy can be prevented.

FIG. 1 is a diagram schematically illustrating a configuration of a vehicle according to an embodiment of the present invention. FIG. 2 is a flowchart showing the flow of DC / DC converter control. FIG. 3 is a flowchart showing the flow of the second DC / DC converter control.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Vehicle configuration>

  FIG. 1 is a diagram schematically illustrating a configuration of a vehicle according to an embodiment of the present invention.

  The vehicle 1 is a range extended electric vehicle.

  The vehicle 1 includes a drive motor 2.

  The drive motor 2 is supplied with AC power and generates a driving force for traveling the vehicle 1. The driving force of the drive motor 2 is transmitted to the left and right drive wheels 4L and 4R via the drive shafts 3L and 3R, respectively. The drive motor 2 has a power generation function. When the vehicle 1 decelerates, the rotation of the drive shafts 3L and 3R is transmitted to the drive motor 2, and the rotation is regenerated into electric power.

  The vehicle 1 includes a driving battery 5 and an inverter 6.

  The driving battery 5 is an assembled battery in which a plurality of secondary batteries are combined.

  The inverter 6 receives supply of DC power from the drive battery 5, converts the DC power into AC power, and supplies the AC power to the drive motor 2. Further, when the drive motor 2 generates power, the inverter 6 converts AC power output from the drive motor 2 into DC power.

  The driving battery 5 can be charged with electric power (electric energy) supplied from the external power source 7. For this charging, the vehicle 1 includes a charging receptacle 8 and a charger 9.

  The external power source 7 is, for example, a household power source (single-phase 100V or single-phase 200V AC power source). One end of a charging cable 10 is connected to the external power source 7. A charging plug 11 is provided at the other end of the charging cable 10.

  The charging receptacle 8 is configured so that the charging plug 11 can be connected (coupled). By connecting the charging plug 11 to the charging receptacle 8, the external power supply 7 and the charging receptacle 8 are electrically connected.

  The charger 9 is electrically connected to the charging receptacle 8. With the charging plug 11 connected to the charging receptacle 8, AC power can be supplied from the external power source 7 to the charger 9 through the charging cable 10. The charger 9 is electrically connected to the terminal of the driving battery 5. The charger 9 converts AC power from the external power source 7 into DC power that can charge the driving battery 5, and charges the driving battery 5 with the DC power.

  The vehicle 1 includes a power generation engine 12 and a generator 13 for charging the drive battery 5.

  Fuel such as gasoline is supplied to the power generation engine 12 from a fuel tank (not shown). The power generation engine 12 rotates the engine output shaft by energy generated by fuel combustion.

  The generator 13 is coupled to the engine output shaft of the power generation engine 12. When the engine output shaft rotates, the generator 13 converts the rotation into electric power (electric energy). The output terminal of the generator 13 is electrically connected to the terminal of the driving battery 5. Therefore, the driving battery 5 can be charged with the electric power generated by the generator 13.

  The vehicle 1 includes an auxiliary battery (12V battery) 14 and a DC / DC converter 15.

  The auxiliary battery 14 is a secondary battery, and is provided as a 12 V power source for an electric load other than the drive motor 2 mounted on the vehicle 1.

  The input terminal of the DC / DC converter 15 is electrically connected to the terminal of the driving battery 5. The output terminal of the DC / DC converter 15 is electrically connected to the terminal of the auxiliary battery 14. When the DC / DC converter 15 operates, the DC power output from the driving battery 5 or the charger 9 is stepped down, and the auxiliary battery 14 can be charged by the stepped-down DC power.

  The vehicle 1 includes an air conditioning unit 16.

  The air conditioning unit 16 is disposed in the engine room at the front of the vehicle 1. The air conditioning unit 16 includes an air conditioning duct 17 and a heater core 18 for heating the air flowing through the air conditioning duct 17. Cooling water that circulates between the power generation engine 12 and the radiator 19 is supplied to the heater core 18 as a heat source. Therefore, when the air conditioning unit 16 heats the passenger compartment, the power generation engine 12 is driven to supply heat to the heater core 18.

  The vehicle 1 includes a battery ECU (electronic control unit) 20.

  The battery ECU 20 includes a CPU and a memory. The battery ECU 20 calculates an SOC (State Of Charge) that is a charging rate corresponding to the charge amount (storage amount) of the drive battery 5 based on the amount of current input to and output from the drive battery 5. Further, communication (CAN communication) can be performed with another ECU mounted on the vehicle 1 using a CAN (Controller Area Network) communication protocol. The battery ECU 20 controls the DC / DC converter 15 based on inputs acquired by SOC and CAN communication.

<DC / DC converter control>

  FIG. 2 is a flowchart showing the flow of DC / DC converter control.

  While the ignition key switch (start switch) of the vehicle 1 is on, the battery ECU 20 repeatedly executes the DC / DC converter control shown in FIG.

  In the DC / DC converter control, first, it is determined whether or not the SOC of the driving battery 5 is greater than or equal to a specified value (step S1).

  If the SOC of the drive battery 5 is greater than or equal to the specified value (YES in step S1), it is next determined whether or not the power generation engine 12 is being driven (step S2).

  When the SOC of the drive battery 5 is equal to or higher than the specified value and the power generation engine 12 is driven (YES in step S2), it is subsequently determined whether or not the vehicle speed is equal to or lower than the specified speed ( Step S3).

  When the vehicle speed is equal to or less than the specified speed, such as when the vehicle 1 is stopped, it is not possible to expect power consumption associated with traveling of the vehicle 1. At this time, since the SOC of the driving battery 5 is equal to or higher than a specified value, the power generation engine 12 is driven for heating by the air conditioning unit 16, and the rotation of the engine output shaft is generated by the generator 13 as electric power (electric energy). Even if converted to, the power may not be stored in the driving battery 5.

  Therefore, when the vehicle speed is equal to or less than the specified speed (YES in step S3), the DC / DC converter 15 is controlled so that the output voltage of the DC / DC converter 15 becomes a high output voltage (for example, 14V) (step). S4).

  In normal times, the DC / DC converter 15 is controlled so that the output voltage of the DC / DC converter 15 becomes a normal output voltage (for example, 13 V). Therefore, the auxiliary battery 14 is charged with the normal output voltage, and the terminal voltage of the auxiliary battery 14 is equal to or lower than the normal output voltage. Therefore, when the DC / DC converter 15 converts the voltage of the electric power generated in the generator 13 into a high output voltage and the high output voltage is supplied to the auxiliary battery 14, the terminal of the auxiliary battery 14 The auxiliary battery 14 is charged until the voltage rises to a high output voltage.

  When the SOC of the drive battery 5 is less than the specified value (NO in step S1), the power generation engine 12 is driven for heating by the air conditioning unit 16, and the generator 13 rotates the engine output shaft to generate electric power. Even if converted into (electric energy), the electric power can be stored in the driving battery 5. Therefore, the DC / DC converter 15 is controlled so that the output voltage becomes the normal output voltage (step S5).

  Even if the SOC of the drive battery 5 is equal to or higher than a specified value, the generator 13 is not generating power when the power generation engine 12 is not driven, so that the output voltage of the DC / DC converter 15 is the normal output voltage. Thus, the DC / DC converter 15 is controlled (step S5).

  Further, even when the SOC of the driving battery 5 is equal to or higher than the specified value and the power generation engine 12 is driven, the vehicle 1 is traveling at a speed higher than the specified speed (in step S3). NO) Since power is consumed as the vehicle 1 travels, the DC / DC converter 15 is controlled so that the output voltage of the DC / DC converter 15 becomes the normal output voltage (step S5).

<Effect>

  As described above, the power generation engine 12 is driven for heating by the air conditioning unit 16 in a state where the SOC of the drive battery 5 is less than the predetermined value, and the driving force of the power generation engine 12 is electrically generated by the generator 13. When converted into energy, the electric energy generated by the generator 13 can be stored in the driving battery 5. If the auxiliary battery 14 is not fully charged, a part of the electric energy generated by the generator 13 is converted into a normal output voltage by the DC / DC converter 15, so that the auxiliary battery 14. To be supplied. As a result, the auxiliary battery 14 is charged. When the terminal voltage of the auxiliary battery 14 matches the normal output voltage, the auxiliary battery 14 is fully charged, and charging of the auxiliary battery 14 is completed.

  When the power generation engine 12 is driven and the generator 13 generates power while the power storage amount of the driving battery 5 is equal to or greater than a predetermined value, the output voltage of the DC / DC converter 15 is increased from the normal output voltage to the high output voltage. It is done. As a result, the electric energy generated by the generator 13 is converted into a high output voltage by the DC / DC converter 15 and supplied to the auxiliary battery 14. Before the output voltage of the DC / DC converter 15 is raised to a high output voltage, the terminal voltage of the driving battery 5 is below the normal output voltage. Therefore, when a high output voltage is supplied from the DC / DC converter 15 to the auxiliary battery 14, the auxiliary battery 14 is charged until the terminal voltage of the auxiliary battery 14 rises to the high output voltage.

  Therefore, it is possible to prevent waste of electric energy during the heating operation of the air conditioning unit 16 in a state where the amount of power stored in the driving battery 5 is equal to or greater than a predetermined value.

  Further, the electrical energy stored in the auxiliary battery 14 exceeding the normal output voltage is consumed as driving power for the auxiliary machine when the drive motor 2 and the generator 13 do not generate power. At this time, the auxiliary battery 14 is not charged by the electric energy of the driving battery 5 until the terminal voltage of the auxiliary battery 14 drops to the normal output voltage. Therefore, the consumption of electric energy stored in the driving battery 5 can be suppressed, and the electricity cost is improved.

<Second DC / DC converter control>

  FIG. 3 is a flowchart showing the flow of the second DC / DC converter control.

  While the ignition key switch (start switch) of the vehicle 1 is on, the battery ECU 20 replaces the DC / DC converter control shown in FIG. 2 or in parallel with the DC / DC converter control shown in FIG. Thus, the DC / DC converter control shown in FIG. 3 may be repeatedly executed.

  In the DC / DC converter control shown in FIG. 3, it is first determined whether or not the SOC of the driving battery 5 is equal to or greater than a specified value (step S11).

  If the SOC of the drive battery 5 is greater than or equal to the specified value (YES in step S11), then whether or not the power regenerated by the drive motor 2 (regenerative power) is greater than or equal to the specified power, that is, the drive motor It is determined whether or not 2 is generating power (step S12).

  When the SOC of the drive battery 5 is equal to or higher than the specified value and the regenerative power by the drive motor 2 is equal to or higher than the specified power (YES in step S12), the output voltage of the DC / DC converter 15 becomes a high output voltage. Then, the DC / DC converter 15 is controlled (step S13).

  When the SOC of the drive battery 5 is less than the specified value (NO in step S11), the drive motor 2 functions as a generator, and even if the rotation of the drive shafts 3L and 3R is regenerated by the drive motor 2 into electric power The regenerative power can be stored in the driving battery 5. Therefore, the DC / DC converter 15 is controlled so that the output voltage becomes the normal output voltage (step S14).

  In addition, even if the SOC of the drive battery 5 is equal to or higher than the specified value, the output of the DC / DC converter 15 is output when the drive motor 3 is not regenerating the drive shafts 3L and 3R with electric power (NO in step S12). The DC / DC converter 15 is controlled so that the voltage becomes the normal output voltage (step S14).

<Effect>

  As described above, when the drive motor 2 regenerates the electric power by the drive motor 2 while the SOC of the drive battery 5 is less than the predetermined value, the electric energy generated by the drive motor 2 is used for driving. It can be stored in the battery 5. If the auxiliary battery 14 is not fully charged, a part of the electric energy generated by the drive motor 2 is converted into a normal output voltage by the DC / DC converter 15, so that the auxiliary battery 14 To be supplied. As a result, the auxiliary battery 14 is charged. When the terminal voltage of the auxiliary battery 14 matches the normal output voltage, the auxiliary battery 14 is fully charged, and charging of the auxiliary battery 14 is completed.

  When the drive motor 3 regenerates the power of the drive shafts 3L, 3R to electric power with the power storage amount of the drive battery 5 being equal to or greater than a predetermined value, the output voltage of the DC / DC converter 15 is increased from the normal output voltage. Raised to voltage. As a result, the electric energy generated by the drive motor 2 is converted into a high output voltage by the DC / DC converter 15 and supplied to the auxiliary battery 14. Before the output voltage of the DC / DC converter 15 is raised to a high output voltage, the terminal voltage of the driving battery 5 is below the normal output voltage. Therefore, when a high output voltage is supplied from the DC / DC converter 15 to the auxiliary battery 14, the auxiliary battery 14 is charged until the terminal voltage of the auxiliary battery 14 rises to the high output voltage.

  Therefore, it is possible to prevent waste of electric energy when the vehicle 1 is decelerated in a state where the charged amount of the driving battery 5 is equal to or greater than a predetermined value.

  Further, the electrical energy stored in the auxiliary battery 14 exceeding the normal output voltage is consumed as driving power for the auxiliary machine when the drive motor 2 and the generator 13 do not generate power. At this time, the auxiliary battery 14 is not charged by the electric energy of the driving battery 5 until the terminal voltage of the auxiliary battery 14 drops to the normal output voltage. Therefore, the consumption of electric energy stored in the driving battery 5 can be suppressed, and the power consumption (fuel consumption) is improved.

<Modification>

  As mentioned above, although embodiment of this invention was described, this invention can also be implemented with another form.

  For example, a range extended electric vehicle has been taken as an example of the vehicle 1, but the present invention can also be applied to a plug-in hybrid car.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Drive motor 5 Drive battery (drive power storage device)
12 Power generation engine (engine)
13 Generator 14 Auxiliary battery (Auxiliary power storage device)
15 DC / DC converter (voltage converter)
16 Air conditioning unit (air conditioner)
20 Battery ECU (control means)

Claims (3)

Power generation means for converting kinetic energy into electrical energy;
A drive power storage device for storing electrical energy;
A drive motor driven by the electrical energy stored in the drive power storage device;
A voltage converter that converts the voltage of the electric energy input from the driving power storage device into a different voltage and outputs the voltage, and
Auxiliary power storage device charged by electrical energy of the voltage after conversion by the voltage conversion device,
When the power generation means generates power in a state where the power storage amount of the drive power storage device is less than a predetermined value, a normal output voltage is output from the voltage conversion device, and the power storage amount of the drive power storage device exceeds a predetermined value. A vehicle comprising: control means for controlling the voltage converter such that a high output voltage higher than the normal output voltage is output from the voltage converter when the power generator generates power in a certain state. Engine,
An air conditioner that heats the vehicle interior using exhaust heat of the engine,
The power generation means is a generator that converts the driving force of the engine into electric energy,
The control means outputs a normal output voltage from the voltage conversion device when the engine is driven for heating by the air conditioner in a state where the amount of electricity stored in the power storage device for driving is less than a predetermined value. When the engine is being driven for heating by the air conditioner in a state where the amount of power stored in the driving power storage device is equal to or greater than a predetermined value, a high output voltage higher than the normal output voltage from the voltage conversion device The vehicle according to claim 1, wherein the voltage conversion device is controlled such that the voltage is output. The power generation means is the drive motor;
The control means outputs a normal output voltage from the voltage converter when the drive motor regenerates electric energy in the state where the storage amount of the drive power storage device is less than a predetermined value, and the drive When the power stored in the power storage device is greater than or equal to a predetermined value and power is regenerated to electrical energy by the drive motor, a high output voltage higher than the normal output voltage is output from the voltage converter. The vehicle according to claim 1, wherein the voltage converter is controlled.

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