JP2012201325A - Plug-in hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plug-in hybrid vehicle capable of improving fuel consumption.SOLUTION: In the plug-in hybrid vehicle 1, a travelable distance when the plug-in hybrid vehicle 1 is allowed to travel using only a motor 2 is obtained on the basis of the remaining power of a battery 4. When an expected travel distance is shorter than the travelable distance, a drive of the motor 2 is controlled so that only the motor 2 is used. When the expected travel distance is not shorter than the travelable distance, and a speed is lower than a threshold, the plug-in hybrid vehicle 1 is allowed to travel using only the motor 2. When the expected travel distance is not shorter than the travelable distance, and the speed is not lower than the threshold, the plug-in hybrid vehicle 1 is allowed to travel using the motor 2 and an engine 3 together.

Description

  The present invention relates to a plug-in hybrid vehicle.

  A motor driven by electric power supplied from a battery and an engine driven by fuel such as gasoline are used in combination, and a plug connected to an AC power source such as a household power source is inserted into the power supply port of the vehicle. There is a plug-in hybrid vehicle that charges a battery (see, for example, Patent Document 1 or Patent Document 2).

  In such a plug-in hybrid vehicle, fuel consumption can be suppressed and fuel consumption can be improved by using only the motor as much as possible until the next charging destination is reached.

  Therefore, for example, it is determined whether or not the planned travel distance from the current location to the destination can be traveled by using only the motor based on the current battery level of the battery, and it is determined that travel is not possible. In some cases, there is a plug-in hybrid vehicle that suppresses the output of the battery to extend the battery remaining amount of the battery and increase the travel of only the motor as much as possible (for example, see Patent Document 3).

  However, in the plug-in hybrid vehicle as described above, when the planned travel distance cannot be traveled using only the motor, the output of the battery is suppressed. Therefore, in the hybrid travel using the motor and the engine together, It is necessary to increase the output, and if there is a lot of hybrid traveling as compared with traveling using only a motor, the fuel consumption may not be improved.

JP 2009-351616 A JP 2010-23739 A JP 2010-89603 A

  An object of this invention is to provide the plug-in hybrid vehicle which can improve a fuel consumption.

  The plug-in hybrid vehicle of the present invention includes a motor, an engine, a battery, a planned travel distance output unit that outputs a planned travel distance from the current location to the destination, and a detection unit that detects the speed of the plug-in hybrid vehicle. Determining the travelable distance when the plug-in hybrid vehicle is traveled using only the motor based on the remaining battery level of the battery, and the motor is when the planned travel distance is shorter than the travelable distance The threshold is changed when the planned travel distance is not shorter than the travelable distance, and changes depending on the remaining battery level and the planned travel distance, respectively. However, when the speed is low, the motor drive is controlled so that only the motor is used, and the planned travel distance is the travelable distance. When not shorter than the distance, and, when the speed is not smaller than the threshold value, and control means for controlling the driving of the motor and the engine to the combined use of the said motor engine.

  This makes it possible to use a motor that increases torque at low speeds when acceleration is required at low speeds, such as when starting or stopping, and increases torque at high speeds when acceleration is required at high speeds. Since the engine can be used, the motor and the engine can be driven efficiently, and the fuel consumption can be improved while suppressing the consumption of the remaining battery power of the battery.

Further, the threshold value may be configured to increase as the remaining battery level increases and as the planned travel distance decreases.
This makes it difficult for the motor alone to run when the battery is low or is still far from the destination. Consumption can be suppressed, and there is no need to increase the engine output when the motor and the engine are used together. For this reason, there is no possibility that the fuel consumption is deteriorated when the hybrid traveling is increased as compared with the traveling using only the motor, in which the estimated traveling distance of the battery is relatively long.

  According to the present invention, fuel efficiency can be improved in a plug-in hybrid vehicle.

It is a figure showing a plug-in hybrid vehicle of an embodiment of the present invention. It is a flowchart for demonstrating operation | movement of a control part. It is a figure which shows an example of EV-HV driving | running | working switching threshold value table.

FIG. 1 is a diagram illustrating a plug-in hybrid vehicle according to an embodiment of the present invention.
A plug-in hybrid vehicle 1 shown in FIG. 1 includes a motor 2, an engine 3, a battery 4 that supplies electric power to the motor 2, a car navigation system 5 (planned travel distance output means), and a speed sensor 6 (detection means). And a control unit 7 (control means).

The motor 2 is an electric motor that outputs power using electric power supplied from the battery 4 and is also a generator for charging the battery 4.
The engine 3 is an internal combustion engine that outputs power using fuel such as gasoline or light oil.

The battery 4 is, for example, a lithium storage battery, and a current sensor for detecting the remaining battery capacity of the battery 4 is provided.
The car navigation system 5 is a device that provides route guidance from the current location to the destination based on the destination and information related to the destination input by the user, and calculates the estimated travel distance from the current location to the destination. It has a function. The car navigation system 5 may have a function that allows the user to directly input the estimated travel distance. Further, instead of the car navigation system 5, the plug-in hybrid vehicle 1 may be provided with a dedicated device (scheduled travel distance output means) that outputs the planned travel distance input by the user to the control unit 7.

The speed sensor 6 is a sensor that detects the speed of the plug-in hybrid vehicle 1.
The control unit 7 includes an EV-HV travel threshold value determination unit 8, a travel method determination unit 9, a motor control unit 10, an engine control unit 11, and a storage unit 12. The EV-HV travel threshold value determination unit 8, the travel method determination unit 9, the motor control unit 10, and the engine control unit 11 are each configured by, for example, an ECU or a CPU, and the storage unit 12 is, for example, a RAM, Consists of ROM and the like.

  The EV-HV driving threshold value determination unit 8 calculates the remaining battery level of the battery 4 based on the current detected by the current sensor of the battery 4, and the estimated driving distance output from the remaining battery level and the car navigation system 5. Based on the above, the electric vehicle travel (hereinafter referred to as EV travel) in which the plug-in hybrid vehicle 1 travels using only the motor 2 and the plug-in hybrid vehicle 1 travels using the motor 2 and the engine 3 in combination. A threshold for switching between hybrid vehicle traveling (hereinafter referred to as HV traveling) is determined.

  Based on the comparison result between the threshold value determined by the EV-HV driving threshold value determination unit 8 and the speed output from the speed sensor 6, the traveling method determination unit 9 uses EV traveling and HV traveling as the currently optimal traveling method. Either one is determined, and the operation of the motor control unit 10 or the engine control unit 11 is controlled according to the determined traveling method.

  When the EV traveling instruction is output from the traveling method determination unit 9, the motor control unit 10 performs the operation of the inverter to drive the motor 2 as an electric motor based on the rotation speed of the motor 2, the current flowing through the motor 2, and the like. Control. Further, when the HV travel instruction is output from the travel method determination unit 9, the motor control unit 10, based on the rotational speed of the motor 2, the current flowing through the motor 2, and the like, drives the motor 2 as an electric motor. The operation of the inverter is controlled in order to control the operation or to drive the motor 2 as a generator.

  When the HV travel instruction is output from the travel method determination unit 9, the engine control unit 11 is based on information indicating the torque of the motor 2 output from the motor control unit 10, information indicating the depression amount of the accelerator pedal, and the like. The engine 3 is driven.

  For example, during HV traveling, the speed of the plug-in hybrid vehicle 1 is medium to high, and therefore, only the engine 3 whose efficiency is relatively good at medium and high speeds is used. Further, when the plug-in hybrid vehicle 1 is accelerated during HV traveling, the power of the engine 3 is assisted by the power of the motor 2. Further, when the plug-in hybrid vehicle 1 decelerates during HV traveling, the motor 2 is used as a generator and the battery 4 is charged.

FIG. 2 is a flowchart for explaining the operation of the control unit 7 during travel of the plug-in hybrid vehicle 1.
First, in step S <b> 1, the EV-HV travel threshold value determination unit 8 of the control unit 7 acquires the estimated travel distance from the car navigation system 5 and the remaining battery level of the battery 4. Further, the traveling method determination unit 9 of the control unit 7 acquires the current speed of the plug-in hybrid vehicle 1 detected by the speed sensor 6, and sets threshold values corresponding to the remaining battery level and the planned traveling distance of the battery 4, respectively. It is taken out from the EV-HV travel switching threshold value table stored in the storage unit 12.

  Next, in step S <b> 2, the travel method determination unit 9 of the control unit 7 determines the distance (hereinafter referred to as EV travel) that allows the plug-in hybrid vehicle 1 to travel only by EV travel based on the remaining battery level of the battery 4. (Referred to as possible distance).

Next, in step S3, the traveling method determination unit 9 determines whether or not the estimated traveling distance is shorter than the EV traveling distance.
When it is determined that the planned travel distance is shorter than the EV travelable distance (Yes in S3), that is, when the planned travel distance can be achieved only by EV travel, in step S4, the travel method determination unit 9 A travel instruction is output to the motor control unit 10. Thereby, EV traveling is performed.

  On the other hand, when it is determined that the planned travel distance is not shorter than the EV travelable distance (No in S3), that is, when it is not possible to run the planned travel distance by EV travel, in step S5, the travel method determination unit 9 The threshold value is acquired from the EV-HV travel threshold value determination unit 8.

Next, in step S6, the traveling method determination unit 9 determines whether the speed detected by the speed sensor 6 is smaller than a threshold value.
When it is determined that the speed is smaller than the threshold (S6 is Yes), that is, when the plug-in hybrid vehicle 1 is traveling at a relatively low speed, in step S4, the traveling method determination unit 9 outputs the EV traveling instruction to the motor. Output to the control unit 10. Thereby, EV traveling is performed.

  On the other hand, when it is determined that the speed is not smaller than the threshold (S6 is No), that is, when the plug-in hybrid vehicle 1 is traveling at a relatively high speed, in step S4, the traveling method determination unit 9 performs HV traveling. Instructions are output to the motor control unit 10 and the engine control unit 11, respectively. Thereby, HV traveling is performed.

Thereafter, steps S1 to S7 are repeatedly executed while the plug-in hybrid vehicle 1 is traveling, and the threshold value is updated each time.
FIG. 3 is a diagram illustrating an example of the EV-HV travel switching threshold value table.

  The EV-HV travel switching threshold value table shown in FIG. 3 corresponds to the remaining battery level (the ratio of the current remaining battery level to the maximum remaining battery level) [%] and the planned travel distance [km], respectively. The threshold value [km / h] is stored.

  For example, the threshold [km / h] corresponding to the remaining battery level [%] of “0 to 10” and the estimated travel distance [km] of “0 to 2” is “0”, and the remaining battery level [ %] Is “0-10”, the threshold [km / h] corresponding to the planned travel distance [km] “2-4” is also “0”, and the remaining battery level [%] is “0”. The threshold [km / h] corresponding to “10” and the estimated travel distance [km] corresponding to “4 to 6” is also “0”.

  Further, for example, the threshold [km / h] corresponding to the remaining battery [%] of “10 to 20” and the estimated travel distance [km] of “0 to 2” is “60”, and the remaining battery The threshold [km / h] corresponding to the amount [%] of “10 to 20” and the estimated travel distance [km] of “2 to 4” is “40”, and the remaining battery level [%] is “ The threshold [km / h] corresponding to “10 to 20” and the estimated travel distance [km] corresponding to “4 to 6” is “30”.

  For example, the threshold [km / h] corresponding to the remaining battery level [%] of “20 to 30” and the estimated travel distance [km] of “0 to 2” is “100”, and the remaining battery level The threshold [km / h] corresponding to the amount [%] of “20 to 30” and the estimated travel distance [km] of “2 to 4” is “60”, and the remaining battery level [%] is “ The threshold value [km / h] corresponding to “20 to 30” and the estimated travel distance [km] corresponding to “4 to 6” is “40”.

  Thus, in the plug-in hybrid vehicle 1 according to the present embodiment, when the speed of the plug-in hybrid vehicle 1 is smaller than the threshold when the planned travel distance cannot be achieved with only the motor 2, EV travel is performed. When the speed is not smaller than the threshold value, HV traveling is performed. Therefore, when acceleration is required at low speed, such as when starting or stopping, the motor 2 that increases torque at low speed can be used, and when acceleration is required at high speed, torque increases at high speed. The engine 3 can be used. Thereby, since the motor 2 and the engine 3 can be driven efficiently, fuel consumption can be improved while suppressing consumption of the battery remaining amount of the battery 4.

  Further, in the plug-in hybrid vehicle 1 of the present embodiment, EV-HV traveling is performed such that the threshold used in step 6 increases as the remaining battery level of the battery 4 increases and as the planned traveling distance decreases. A plurality of threshold values are stored in the switching threshold table. As a result, when the remaining battery level of the battery 4 is low or when the battery 4 is still far from the destination, EV travel is difficult to be performed. When the motor 2 and the engine 3 are used together, there is no need to increase the output of the engine 3. For this reason, even if the planned travel distance is relatively long and HV traveling is increased as compared with EV traveling, there is no possibility that fuel consumption will deteriorate.

DESCRIPTION OF SYMBOLS 1 Plug-in hybrid vehicle 2 Motor 3 Engine 4 Battery 5 Car navigation system 6 Speed sensor 7 Control part 8 EV-HV driving threshold value determination part 9 Driving method determination part 10 Motor control part 11 Engine control part 12 Storage part

Claims (2)

A motor,
Engine,
Battery,
A planned travel distance output means for outputting a planned travel distance from the current location to the destination;
Detection means for detecting the speed of the plug-in hybrid vehicle;
Based on the remaining battery level of the battery, the travelable distance when traveling the plug-in hybrid vehicle using only the motor is obtained, and when the planned travel distance is shorter than the travelable distance, only the motor The driving of the motor is controlled so that is used, and when the planned travel distance is not shorter than the travelable distance, and the threshold value varies depending on the remaining battery level and the planned travel distance, respectively. When the speed is small, driving of the motor is controlled so that only the motor is used, and when the planned travel distance is not shorter than the travelable distance and when the speed is not smaller than the threshold value Control means for controlling driving of the motor and the engine so as to use the motor and the engine together;
Plug-in hybrid vehicle equipped with. The plug-in hybrid vehicle according to claim 1,
The plug-in hybrid vehicle is characterized in that the threshold value increases as the remaining battery level increases and as the planned travel distance decreases.

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