JP2015214262A - vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recover a state of charge of a battery at early timing after the end of execution of a temporary acceleration control to temporarily increase power output from a motor-generator in a vehicle including an engine, the motor-generator, and the battery.SOLUTION: A hybrid electric vehicle comprises: an engine; a battery; a motor-generator; and a temporary acceleration switch, an ECU 100 executing a temporary acceleration control to temporarily increase power output from the motor-generator in response to the depression of the temporary acceleration switch (S10 to S13). Within a predetermined period after the end of the temporary acceleration control, the ECU 100 recovers an SOC at early timing by changing the correspondence between the SOC used for normal charging and required charging power so as to increase the required charging power (S20 to S23).

Description

  The present invention relates to a vehicle that includes an engine and a motor generator, and that can travel with the power of at least one of the engine and the motor generator.

  Japanese Patent Laying-Open No. 2011-189889 (Patent Document 1) discloses a hybrid vehicle including an engine, a motor generator, a battery that charges and discharges electric power between the motor generator, and an acceleration button operated by a user. Has been.

  In this hybrid vehicle, when the acceleration button is pressed, if the battery charge amount (hereinafter also referred to as “SOC”) at the time when the acceleration button is pressed is equal to or greater than a threshold value, the output of the motor generator (that is, The powerful assist mode is executed to increase the battery discharge power). On the other hand, when the SOC when the acceleration button is pressed is less than the threshold value, the battery is precharged until the SOC exceeds the threshold value before the strong assist mode is executed, and the SOC is equal to or higher than the threshold value. Execute the powerful assist mode after

JP2011-189889A

  In the hybrid vehicle disclosed in Patent Document 1, when the strong assist mode is executed, more battery power is consumed than before the execution of the strong assist mode. Therefore, immediately after the end of the strong assist mode, the SOC is lower than before the execution of the strong assist mode. Therefore, after the end of the strong assist mode, there is a possibility that the operation requested by the user cannot be realized until the SOC is recovered. Therefore, it is desirable to recover the SOC early after the end of the strong assist mode. However, Patent Document 1 makes no mention of such a problem and means for solving the problem.

  The present invention has been made to solve the above-described problems, and an object thereof is to execute temporary acceleration control for temporarily increasing the output of a motor generator in a vehicle including an engine, a motor generator, and a battery. Is to recover the amount of power stored in the battery early.

  A vehicle according to the present invention includes an engine and a motor generator, is a vehicle that can be driven by at least one of the engine and the motor generator, and is operated by a user and a battery that charges and discharges electric power to and from the motor generator. A temporary acceleration switch, and a control device that executes temporary acceleration control for temporarily increasing the output of the motor generator when the temporary acceleration switch is operated. When charging the battery within a predetermined period after the execution of the temporary acceleration control is finished, the control device changes the correspondence relationship between the amount of charge of the battery and the charge power of the battery so that the charge power of the battery increases. .

  According to such a configuration, the charging power of the battery is increased within a predetermined period after the execution of the temporary acceleration control is completed, compared to before the execution of the temporary acceleration control. Therefore, after the execution of the temporary acceleration control is completed, the amount of power stored in the battery can be recovered early.

1 is an overall block diagram of a vehicle. It is a flowchart which shows the flow of the process which ECU performs. It is a figure which shows an example of the correspondence of SOC used for normal charge, and request | requirement charging power. It is a figure which shows an example of the change aspect of SOC when a temporary acceleration switch is pushed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  In this specification, the term “electric power” may mean electric power (work rate) in a narrow sense, and may mean electric energy (work amount) or electric energy, which is electric power in a broad sense, and the term is used. It is interpreted elastically according to the situation to be done.

  FIG. 1 is an overall block diagram of a vehicle 1 according to the present embodiment. The vehicle 1 includes an engine 10, a first motor generator (hereinafter also referred to as “first MG”) 20, a second motor generator (hereinafter also referred to as “second MG”) 30, a power split device 40, a PCU (Power Control). Unit) 50, battery 60, drive wheel 80, and ECU (Electronic Control Unit) 100.

  The vehicle 1 is a hybrid vehicle that travels by at least one of the power of the engine 10 and the power of the second MG 30 (that is, the power of the battery 60).

  The power generated by the engine 10 is divided by the power split device 40 into a path transmitted to the drive wheels 80 and a path transmitted to the first MG 20.

  First MG 20 and second MG 30 are three-phase AC rotating electric machines driven by PCU 50. First MG 20 generates power using the power of engine 10 divided by power split device 40. First MG 20 can also generate electric power using the kinetic energy of vehicle 1 transmitted from drive wheel 80 via power split device 40 when vehicle 1 is decelerated.

  Second MG 30 generates driving force for vehicle 1 using at least one of the electric power stored in battery 60 and the electric power generated by first MG 20. Second MG 30 generates power using the kinetic energy of vehicle 1 transmitted from drive wheels 80 when vehicle 1 is decelerated. Second MG 30 can also generate power using the power of engine 10 transmitted via power split device 40.

  Hereinafter, the power generated by at least one of the first MG 20 and the second MG 30 using the power of the engine 10 is also referred to as “engine generated power”. Furthermore, the power generated by at least one of the first MG 20 and the second MG 30 using the kinetic energy of the vehicle 1 when the vehicle 1 is decelerated is also referred to as “regenerative power generation power”.

  Power split device 40 is a planetary gear mechanism including a sun gear, a pinion gear, a carrier, and a ring gear. The pinion gear meshes with each of the sun gear and the ring gear. The carrier supports the pinion gear so as to be able to rotate and is coupled to the crankshaft of the engine 10. The sun gear is connected to the rotation shaft of the first MG 20. The ring gear is connected to the rotation shaft of second MG 30 and drive wheel 80.

  PCU 50 converts the DC power stored in battery 60 into AC power that can drive first MG 20 and second MG 30. The PCU 50 converts AC power generated by the first MG 20 and the second MG 30 into DC power that can charge the battery 60.

  Battery 60 is electrically connected to first MG 20 and second MG 30 via PCU 50, and charges and discharges power between first MG 20 and second MG 30.

  The vehicle 1 is provided with a temporary acceleration switch 2. When the user performs an operation of pressing the temporary acceleration switch 2, the temporary acceleration switch 2 outputs a signal (hereinafter referred to as “temporary acceleration request signal”) requesting the vehicle 1 to be accelerated temporarily to the ECU 100.

  Further, although not shown, the vehicle 1 detects the accelerator opening (the amount of accelerator pedal operation by the user), the vehicle speed sensor that detects the vehicle speed, and the battery 60 status (voltage, current, temperature, etc.). And a plurality of sensors for detecting various physical quantities necessary for controlling the vehicle 1. Each of these sensors outputs a detection result to ECU 100.

  The ECU 100 includes a CPU (Central Processing Unit) and a memory (not shown), and executes predetermined arithmetic processing based on information stored in the memory and information from each sensor. ECU 100 controls each device mounted on vehicle 1 based on the result of the arithmetic processing.

  ECU 100 calculates the amount of charge (State Of Charge, hereinafter referred to as “SOC”) of battery 60 based on the state of battery 60 (the detection result of the monitoring sensor). As a method of calculating the SOC, various known methods such as a method of calculating using the relationship between the voltage of the battery 60 and the SOC and a method of calculating using the integrated value of the current can be used. In addition, SOC is generally represented by the percentage which makes the maximum capacity | capacitance of the battery 60 100%.

  The ECU 100 travels using the outputs of both the engine 10 and the second MG 30 (hereinafter referred to as “HV travel”) and travels using the output of the second MG 30 (hereinafter “ (Also referred to as “EV traveling”) is selectively performed. For example, ECU 100 performs HV traveling when the traveling load is large and engine 10 can be operated efficiently. On the other hand, the ECU 100 performs EV traveling when the traveling load is small and the engine 10 cannot be operated efficiently, such as when the vehicle is stopped or traveling at a low speed.

  ECU 100 controls charging / discharging of battery 60 such that the SOC is included in a predetermined control range (a range from the control lower limit value to the control upper limit value).

  When the SOC is included in the control range, ECU 100 charges battery 60 by normal charging. During normal charging, the ECU 100 calculates electric power (hereinafter referred to as “required charging electric power”) to be input to the battery 60 based on the SOC, and generates or decelerates engine generated power during HV traveling (when the engine 10 is operating). The engine 10 and the PCU 50 are controlled so that the regenerative power at the time becomes the required charging power. Therefore, during normal charging, the battery 60 is charged with power corresponding to the required charging power during HV traveling or deceleration. The method for calculating the required charging power will be described later in detail.

  On the other hand, when the SOC becomes less than the control lower limit value, ECU 100 charges battery 60 by forced charging. During the forcible charging, the ECU 100 forcibly operates the engine 10 until the SOC recovers to a value larger than the control lower limit value by a predetermined value even if the traveling load is small and the efficiency of the engine 10 is low. 60 is charged.

  When the ECU 100 receives a temporary acceleration request signal from the temporary acceleration switch 2, the ECU 100 executes control for temporarily increasing the output of the second MG 30 (hereinafter also referred to as “temporary acceleration control”).

  In the vehicle 1 having the above-described configuration, when receiving a temporary acceleration request signal from the temporary acceleration switch 2, the ECU 100 executes temporary acceleration control for temporarily increasing the output of the second MG 30 as described above.

  During the execution of the temporary acceleration control, the power consumption of the second MG 30 (that is, the discharged power of the battery 60) temporarily increases, and therefore the SOC reduction rate becomes larger than when the temporary acceleration control is not executed. For this reason, immediately after the execution of the temporary acceleration control is completed, the SOC is considerably lower than before the execution of the temporary acceleration control. Therefore, after the execution of the temporary acceleration control is completed, there is a possibility that the operation requested by the user cannot be realized until the SOC is recovered. For example, the EV travelable distance requested by the user may not be satisfied, or the temporary acceleration control may not be executed even if the user subsequently presses the temporary acceleration switch 2.

  Furthermore, if the SOC further decreases due to EV traveling or the like after the end of the temporary acceleration control, the SOC becomes less than the control lower limit value, and the above-described forced charging may be started. During forced charging, since the engine 10 is forcibly operated even when the traveling load is small and the efficiency of the engine 10 is low, the fuel consumption may be deteriorated.

  Therefore, the ECU 100 according to the present embodiment performs control for changing the correspondence relationship between the SOC used for normal charging and the required charging power so as to increase the required charging power within a predetermined period after the end of the temporary acceleration control (hereinafter referred to as “required charging power”). (Referred to as “required charge power increase control”). Thereby, SOC is recovered early.

  FIG. 2 is a flowchart showing a flow of processing performed by the ECU 100. This flowchart is repeatedly executed at a predetermined cycle.

  In step (hereinafter, step is abbreviated as “S”) 10, ECU 100 determines whether or not the temporary acceleration switch has been pressed (turned on). If the temporary acceleration switch has not been pressed (NO in S10), ECU 100 ends the process.

  If the temporary acceleration switch is pressed (YES in S10), ECU 100 moves the process to S11 and executes the above-described temporary acceleration control (control for temporarily increasing the output of second MG 30).

  In S12, ECU 100 determines whether or not the accelerator opening is smaller than the threshold value. This process is a process for determining whether or not the termination condition for the temporary acceleration control is satisfied.

  If the accelerator opening is larger than the threshold value (NO in S12), ECU 100 determines that the termination condition for the temporary acceleration control is not satisfied, returns the process to S11, and continues the execution of the temporary acceleration control.

  On the other hand, when the accelerator opening is smaller than the threshold value (YES in S12), ECU 100 determines that the termination condition for the temporary acceleration control is satisfied, moves the process to S13, and terminates the execution of the temporary acceleration control.

  After completing the execution of the temporary acceleration control, the ECU 100 starts a counter for measuring the elapsed time in S20, and executes the above-described required charging power increase control in S21.

  FIG. 3 is a diagram illustrating an example of a correspondence relationship between the SOC used for normal charging and the required charging power. The ECU 100 stores the correspondence shown in FIG. 3 in advance, and determines the required charging power corresponding to the current SOC with reference to this correspondence during normal charging.

  When the required charging power increase control is not executed, ECU 100 refers to the correspondence relationship indicated by the one-dot chain line in FIG. 3 and determines the required charging power corresponding to the current SOC. When the SOC is in a region lower than the center of the control range (SOC control center), the required charging power is set to a larger value as the SOC is lower. When the SOC is in a region higher than the SOC control center, the required charging power is set to a negative (discharge side) value.

  On the other hand, during execution of the required charging power increase control, ECU 100 refers to the correspondence relationship indicated by the solid line in FIG. 3 to determine the required charging power corresponding to the current SOC. In the correspondence relationship indicated by the solid line in FIG. 3, the required charging power is set to a larger value for the same SOC than the correspondence relationship indicated by the one-dot chain line in FIG. 3. That is, the required charging power increase control is a control for changing the correspondence relationship between the SOC and the required charging power so that the required charging power increases. During the execution of the required charging power increase control, the charging power of the battery 60 is increased as compared with the case where the required charging power increase control is not executed. Thereby, SOC is recovered early.

  Returning to FIG. 2, in S22, ECU 100 determines whether or not the counter is equal to or greater than a predetermined value (that is, whether or not the elapsed time after the end of temporary acceleration control has exceeded a predetermined value).

  If the counter is less than the predetermined value (NO in S22), ECU 100 returns the process to S21 and continues execution of the required charging power increase control.

  If the counter is equal to or greater than the predetermined value (YES in S22), ECU 100 moves the process to S23 and ends the execution of the required charging power increase control. That is, ECU 100 again determines the required charging power with reference to the correspondence relationship indicated by the one-dot chain line in FIG.

  FIG. 4 is a diagram illustrating an example of a change state of the SOC when the temporary acceleration switch 2 is pressed. When the temporary acceleration switch 2 is pressed at time t1, temporary acceleration control is started. Along with this, the output of the second MG 30 (discharge power of the battery 60) is increased, so that the SOC starts to decrease.

  When the accelerator opening becomes less than the threshold value at time t2, the execution of the temporary acceleration control is terminated and the counter is started.

  In the period from time t2 when the execution of the temporary acceleration control is ended to time t3 when the counter reaches the set value, the required charging power increase control is executed. Therefore, the SOC can be recovered earlier than in the case where the required charging power increase control is not executed (see the one-dot chain line).

  After time t3, since the SOC is recovered by the required charging power increase control, the operation requested by the user is easily realized as before the execution of the temporary acceleration control. For example, the EV travelable distance requested by the user can be satisfied, and the temporary acceleration control can be continuously executed.

  Furthermore, in the present embodiment, after the temporary acceleration control is finished, the SOC is recovered by increasing the required charging power during normal charging, so that forced charging can be avoided and fuel consumption is deteriorated. Can be suppressed. That is, when the SOC is recovered by forced charging, the engine 10 is forcibly operated even when the traveling load is small and the efficiency of the engine 10 is low (for example, when the vehicle is stopped). There is a tendency for fuel consumption to deteriorate compared to. However, in the present embodiment, since the SOC is recovered by normal charging, deterioration of fuel consumption can be suppressed as compared with the case where the SOC is recovered by forced charging.

  As described above, ECU 100 according to the present embodiment changes the correspondence relationship between the SOC used for normal charging and the required charging power so that the required charging power increases within a predetermined period after the end of temporary acceleration control. (See FIG. 3). As a result, the SOC can be recovered early after the end of the temporary acceleration control.

  In the above-described actual embodiment, the case where the present invention is applied to a so-called split-type hybrid vehicle including an engine and two motor generators (first MG 20 and second MG 30) has been described. However, the present invention is applicable. The vehicle is not limited to the hybrid vehicle of the system shown in the above embodiment. For example, the present invention can be applied to a general series-type or parallel-type hybrid vehicle including an engine and one motor generator.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 vehicle, 2 temporary acceleration switch, 10 engine, 20 1st MG, 30 2nd MG, 40 power split device, 60 battery, 80 driving wheel, 100 ECU.

Claims (1)

A vehicle comprising an engine and a motor generator, capable of traveling with the power of at least one of the engine and the motor generator,
A battery that charges and discharges power to and from the motor generator;
A temporary acceleration switch operated by the user;
A controller for executing temporary acceleration control for temporarily increasing the output of the motor generator when the temporary acceleration switch is operated;
When charging the battery within a predetermined period after the execution of the temporary acceleration control is completed, the control device indicates a correspondence relationship between the storage amount of the battery and the charging power of the battery, and the charging power of the battery A vehicle that changes to increase.

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