JP2015107689A - Hybrid vehicle and control method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid vehicle and a control method for the same that can improve travelling performance of the vehicle without deteriorating fuel economy of the vehicle.SOLUTION: A capacitor 13 is arranged in parallel with a battery 8, and the capacitor 13 and the battery 8 are connected through a change-over switch 14 to an inverter 7. When a demand load to an HEV 1A is within a predetermined high load region, the inverter 7 and the capacitor 13 are connected by the change-over switch 14 so that a motor generator 6 is driven by power supplied from the capacitor 13, while when the demand load is within a predetermined low load region, the inverter 7 and the battery 8 are connected by the change-over switch 14 so that the motor generator 6 is driven by power supplied from the battery 8.

Description

  The present invention relates to a hybrid vehicle and a control method therefor, and more particularly to a hybrid vehicle and a control method therefor that can improve traveling performance without deteriorating the fuel consumption of the vehicle.

  In recent years, a hybrid vehicle (hereinafter referred to as “HEV”) including a hybrid system having an engine and a motor generator has attracted attention from the viewpoint of improving fuel efficiency and environmental measures (for example, refer to Patent Document 1).

  In this HEV, a part of the driving force generated by the engine is replaced by a motor generator using a battery as a power source, while regenerative energy during braking is converted into electric power by the motor generator and stored in the battery. Has been done. Therefore, in order to improve the running performance of HEV, it is necessary to increase the output and capacity of the battery.

  However, when a large number of cells constituting the battery are added in order to increase the output and capacity of the battery, the battery becomes larger and heavier, resulting in a problem that the fuel efficiency of the HEV deteriorates.

JP 2002-238105 A

  The objective of this invention is providing the hybrid vehicle which can improve the driving | running performance, without deteriorating the fuel consumption of a vehicle, and its control method.

  A hybrid vehicle of the present invention that achieves the above object is a hybrid vehicle comprising a hybrid system having a motor generator and an engine connected to a battery via an inverter, and a control means for controlling the hybrid system. The changeover switch is connected to the inverter via a changeover switch so as to be in parallel with the battery, and the control means is configured to change the changeover switch when a load necessary for driving the hybrid electric vehicle is in a preset high load region. By connecting the inverter and the capacitor by controlling the capacitor as a power source of the motor generator, when the load necessary for the operation of the hybrid electric vehicle is in a preset low load region, Control the changeover switch to connect the inverter and the battery In Rukoto, is characterized in that the battery power supply of the electric generator.

  A control method for a hybrid vehicle of the present invention that achieves the above object is a control method for a hybrid vehicle comprising a hybrid system having a motor generator and an engine connected to a battery via an inverter, wherein the capacitor is connected to the battery. When connected to the inverter via a changeover switch so as to be in parallel and the load necessary for driving the hybrid electric vehicle is in a preset high load region, switch to the connection between the inverter and the capacitor. When the motor generator is driven by the electric power supplied from the capacitor and the load necessary for the operation of the hybrid electric vehicle is in a preset low load region, the connection is made between the inverter and the battery. And driving the motor generator with electric power supplied from the battery. It is an.

  According to the hybrid vehicle and the control method thereof of the present invention, when the required load on the hybrid vehicle is in a preset high load region, electric power is supplied from the capacitor to the motor generator in a short time with a higher output than the battery. On the other hand, when the required load is in a preset low load region, since power is supplied from the conventional battery to the motor generator, without deteriorating the fuel consumption of the hybrid vehicle, Its driving performance can be improved

1 is a configuration diagram of a hybrid vehicle according to a first embodiment of the present invention. It is a flowchart explaining the control method of the hybrid vehicle which consists of the 1st Embodiment of this invention. It is a graph which shows typically an example of a division of a driving field of a hybrid vehicle. It is a block diagram of the hybrid vehicle which consists of the 2nd Embodiment of this invention. It is a flowchart explaining the control method of the hybrid vehicle which consists of the 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a hybrid vehicle according to a first embodiment of the present invention. This hybrid vehicle (hereinafter referred to as “HEV”) 1A includes an engine 5 and a motor generator 6 that are connected via a transmission 4 to an output shaft 3 that transmits driving force to a pair of left and right driving wheels 2 and 2. A hybrid system 9 having a battery 8 electrically connected to the motor generator 6 through an inverter 7 is provided. A wet multi-plate clutch 10 and a fluid coupling 11 are sequentially provided between the transmission 4 and the engine 5. A motor clutch 12 that connects and disconnects the driving force is interposed between the transmission 4 and the motor generator 6.

  A capacitor 13 arranged in parallel with the battery 8 is connected to the inverter 7 via a changeover switch 14. The capacitor 13 is smaller in capacity than the battery 8, but has a characteristic that the output is high and the time required for charging and discharging is short.

  Further, as the changeover switch 14, a two-circuit two-contact (ON-ON) type circuit switch having a contact c connected to the inverter 7 as a common contact is used. FIG. 1 shows a state where the contact c and the terminal on the battery 8 side are connected.

  The hybrid system 9 and the changeover switch 14 are connected to the ECU 15 as control means through a signal line (indicated by a one-dot chain line).

  An embodiment of such a control method by the ECU 15 in the HEV 1A will be described below based on FIG.

  The ECU 15 confirms the degree of load required for the operation required for the HEV 1A (hereinafter referred to as “required load”) with reference to the map during the operation of the HEV 1A (S10). FIG. 3 illustrates an example of the map in which the operating region of the HEV 1A is schematically divided using the engine speed and engine torque of the diesel engine 5 as parameters. The high load region in FIG. 3 corresponds to a case where the accelerator is greatly depressed when the HEV 1A starts or suddenly accelerates. Further, the low load region corresponds to a case where the accelerator is slightly depressed, such as when the HEV 1A is slowly accelerating. Further, the regeneration area corresponds to when the HEV 1A is braked.

  When the required load on the HEV 1A is in a high load region, the changeover switch 14 is switched to the capacitor 13 side (S12), the motor generator 6 is rotationally driven using the capacitor 13 as a power source, and the motor clutch 12 is connected. By doing so (S16), a part of the driving force of the diesel engine 5 is assisted by the driving force of the motor generator 6 (S18).

  On the other hand, if the required load on the HEV 1A is in the low load region, the changeover switch 14 is switched to the battery 8 side (S14), the motor generator 6 is driven to rotate using the battery 8 as a power source, and the motor clutch By connecting 12 (S16), a part of the driving force of the diesel engine 5 is assisted by the driving force of the motor generator 6 (S18).

  In this way, when the HEV 1A starts or suddenly accelerates, power is supplied from the capacitor 13 to the motor generator 6 in a short time while the battery 13 is slowly accelerating. Electric power is supplied from 8 to the motor generator 6.

  Therefore, the conventional battery 8 is specialized in the capacity type, and the capacity of the hybrid system 9 can be increased while the output of the power can be increased by the capacitor 13. Therefore, the driving performance can be improved without deteriorating the fuel consumption of the HEV 1A. Can be improved.

  In addition, since the capacitor 13 and the changeover switch 14 can be installed at a lower cost than in general adding a large number of cells of the battery 8, an increase in the manufacturing cost of the HEV 1A can be suppressed.

  FIG. 4 shows a hybrid vehicle according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same location as FIG. 1, and the description is abbreviate | omitted.

  The HEV 1B is configured such that voltage sensors 16 and 17 for measuring the state of charge are installed in the battery 8 and the capacitor 13, respectively, and connected to the ECU 15 through signal lines.

  An embodiment of such a control method by the ECU 15 in the HEV 1B will be described below based on FIG. In addition, the same control number as FIG. 2 is attached | subjected to the same step number, and the description is abbreviate | omitted.

  The ECU 15 checks the degree of the required load on the HEV 1B with reference to the map during the operation of the HEV 1B (S10), and when the required load is in the regenerative region (for example, see FIG. 3), the changeover switch 14 is switched to the capacitor 13 side (S20), and the motor clutch 12 is connected (S22), whereby the power generated by the motor generator 6 is charged in the capacitor 13 (S24).

  When the voltage sensor 16 detects that the capacitor 13 is fully charged (S26), the switch 14 is switched to the battery 8 side (S28), and the battery 8 is charged with the electric power generated by the motor generator 6. (S30). The charging of the battery 8 is stopped when the voltage sensor 17 detects that the battery has been charged up to the rated maximum capacity (S32).

  In this way, relatively large power generated at the beginning of braking is stored in the capacitor 13 in a shorter time than before, for example, during braking of the HEV 1B, while relatively small power generated thereafter. Is stored in the normal battery 8, and the load on the battery 8 is reduced, so that the life of the battery 8 can be extended.

1A, 1B HEV
5 Diesel Engine 6 Motor Generator 7 Inverter 8 Battery 9 Hybrid System 13 Capacitor 14 Changeover Switch 15 ECU
16, 17 Voltage sensor

Claims (3)

In a hybrid vehicle comprising a hybrid system having a motor generator and an engine connected to a battery via an inverter, and a control means for controlling the hybrid system,
A capacitor is connected to the inverter via a changeover switch so as to be in parallel with the battery,
The control means includes
When the load necessary for driving the hybrid electric vehicle is in a preset high load region, the changeover switch is controlled to connect the inverter and the capacitor, thereby connecting the capacitor to the motor generator. Power and
When the load necessary for driving the hybrid electric vehicle is in a preset low load region, the changeover switch is controlled to connect the inverter and the battery, thereby connecting the battery to the motor generator. A hybrid vehicle characterized by being a power source.   The control means charges the capacitor by connecting the inverter and the capacitor by controlling the changeover switch when a load necessary for driving the hybrid electric vehicle is in a preset regeneration region. The hybrid vehicle according to claim 1, wherein the battery is charged by connecting the inverter and the battery after the capacitor is fully charged. A method for controlling a hybrid vehicle comprising a hybrid system having a motor generator and an engine connected to a battery via an inverter,
A capacitor is connected to the inverter via a changeover switch so as to be in parallel with the battery,
When the load necessary for driving the hybrid electric vehicle is in a preset high load region, the inverter is connected to the capacitor, and the motor generator is driven by the electric power supplied from the capacitor. ,
When the load necessary for driving the hybrid electric vehicle is in a preset low load region, the inverter is connected to the battery, and the motor generator is driven by the electric power supplied from the battery. A control method of a hybrid vehicle characterized by the above.

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