JP2015214265A - vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve SOC recovery while suppressing the fuel consumption of an engine during the execution of an SOC recovery mode in a hybrid electric vehicle including the engine and a motor-generator.SOLUTION: A hybrid electric vehicle comprises: an engine; a battery; a motor-generator; and a regenerative level adjustment device, and an ECU determines whether a required regenerative level received from the regenerative level adjustment device is higher than a predetermined level during execution of an SOC recovery mode (mode for recovering an SOC of the battery) (S12). If the required recovery level is lower than the predetermined level (S12, NO), the ECU prohibits an engine intermittent operation (S13). If the required recovery level is higher than the predetermined level (S12, YES), the ECU permits the engine intermittent operation (S14 to S16).

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. 2011-219093 (Patent Document 1) discloses a hybrid vehicle including an engine, a battery, a motor generator that can be driven by electric power stored in the battery, and a charge priority button. The hybrid vehicle travels in the quick charge travel mode when the charge priority button is turned on. In the quick charge running mode, the power generated by the motor generator using the remainder of the engine power while generating the driving power using part of the engine power while making the engine output higher than the user's required driving power Thus, the charged amount of the battery (hereinafter also referred to as “SOC”) is recovered by rapidly charging the battery.

JP 2011-219039 A

  However, in the hybrid vehicle disclosed in Patent Document 1, if the charge priority button is turned on, even if the SOC recovery can be expected only with the regenerative power of the motor generator without using the power of the engine, The engine is always operated with the highest priority given to recovering the SOC. Therefore, the fuel consumption of the engine may increase more than necessary, and the fuel consumption may deteriorate.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a fuel for an engine in a vehicle having an engine and a motor generator during execution of a recovery mode for recovering the charged amount of the battery. It is to restore the amount of electricity stored in the battery while suppressing consumption.

  A vehicle according to the present invention includes an engine and a motor generator, and is capable of traveling with at least one of the power of the engine and the motor generator. The vehicle is electrically connected to the motor generator, and the motor generator is configured using the power of the engine. A battery charged by at least one of engine generated power to be generated and regenerative power generated by the motor generator using kinetic energy of the vehicle, and a regenerative level setting unit for setting a required level of regenerative power according to a user operation And a control unit that determines whether or not to allow the engine to stop based on the required level of regenerative power set by the regenerative level setting unit during the execution of the recovery mode for recovering the amount of power stored in the battery.

  According to such a configuration, during execution of the recovery mode, the engine stop is not uniformly prohibited (the engine is always operated), but the engine is allowed to stop based on the required level of regenerative power. Or not is determined. For this reason, for example, when the required level of regenerative power is higher than a predetermined level, the regenerative power can be expected to recover the amount of charge stored in the battery.Therefore, regenerative power is allowed while stopping the engine and suppressing fuel consumption. This makes it possible to recover the amount of power stored in the battery. As a result, while the recovery mode is being executed, the amount of power stored in the battery can be recovered while suppressing fuel consumption of the engine.

  Preferably, the control unit does not allow the engine to stop when the recovery mode is being executed and the required level of regenerative power is lower than a predetermined level, and the control unit is not executing the recovery mode and the required level of regenerative power is predetermined. If it is higher than the level, the engine is allowed to stop.

  According to such a configuration, if the required level of regenerative power is lower than the predetermined level during the execution of the recovery mode, it is not a situation in which the rechargeable power can be expected to recover the amount of charge of the battery. Ban. Thereby, the storage amount of the battery can be recovered by the engine generated power. On the other hand, when the required level of regenerative power is greater than a predetermined level, the engine can be stopped because the regenerative power can be expected to restore the amount of power stored in the battery. As a result, the amount of power stored in the battery can be recovered by regenerative power while suppressing fuel consumption of the engine.

  Preferably, the recovery mode is a mode for recovering the stored amount of the battery by charging the battery with electric power larger than the predetermined electric power. The control unit operates the engine when the recovery mode is being executed and the required level of regenerative power is higher than a predetermined level, and the actual regenerative power is lower than the predetermined power. If too large, stop the engine.

  According to such a configuration, when the recovery mode is being executed and the required level of regenerative power is larger than the predetermined level, if the actual regenerative power is smaller than the predetermined power, the engine is operated and the engine generated power is Thus, the amount of power stored in the battery can be recovered. On the other hand, when the actual regenerative power is larger than the predetermined power, the stored amount of the battery can be quickly recovered with the regenerative power larger than the predetermined power while stopping the engine and suppressing fuel consumption.

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 change of the battery charging power during execution of SOC recovery mode.

  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.

  The battery 60 includes, for example, nickel metal hydride, lithium ions, and the like. The battery 60 is charged with at least one of the engine generated power and the regenerative power described above.

The vehicle 1 is provided with an SOC recovery switch 2 and a regeneration level adjusting device 3.
The SOC recovery switch 2 uses a signal (hereinafter referred to as “SOC recovery request signal”) for requesting that the stored amount of battery 60 (State Of Charge, hereinafter referred to as “SOC”) be recovered from its current value as a user operation. In response, it outputs to ECU100.

  The regeneration level adjusting device 3 is a device for the user to set the level of regenerative power requested by the user (hereinafter also referred to as “required regeneration level”). The regeneration level adjusting device 3 is disposed in the vicinity of the steering, for example, as a paddle type switch. The regeneration level adjusting device 3 outputs the requested regeneration level set by the user to the ECU 100.

  Further, although not shown, the vehicle 1 has various physical quantities necessary for controlling the vehicle 1 such as a vehicle speed sensor that detects the vehicle speed and a monitoring sensor that detects the state (voltage, current, temperature, etc.) of the battery 60. A plurality of sensors for detection are provided. 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 SOC of battery 60 based on the result of detecting the state of battery 60 by 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. The SOC is expressed as a percentage where the maximum capacity of the battery 60 is 100%.

  The ECU 100 limits the regenerative power generated when the vehicle decelerates (for example, when the user is not stepping on the accelerator pedal) so as not to exceed the requested regenerative level received from the regenerative level adjusting device 3. Therefore, the user can adjust the regenerative braking force during vehicle deceleration by operating the regeneration level adjusting device 3 to adjust the required regeneration level. The regenerative power is charged in the battery 60.

  When the ECU 100 receives the “SOC recovery request signal” from the SOC recovery switch 2, the ECU 100 controls the vehicle 1 in a mode for recovering the SOC from the current value (hereinafter referred to as “SOC recovery mode”). During execution of the SOC recovery mode, the ECU 100 continues to charge the battery 60 with electric power (unit: watts) larger than a predetermined “threshold value α” while generating the vehicle driving force requested by the user. By controlling engine 10, first MG 20 and second MG 30, the SOC is quickly recovered to a predetermined target value (for example, an upper limit value or a value close to the upper limit value) larger than the current value.

  In the vehicle 1 having the above-described configuration, the ECU 100 recovers the SOC early by continuing to charge the battery 60 with electric power larger than the threshold value α as described above during execution of the SOC recovery mode.

  At this time, when the required regeneration level exceeds a predetermined level (a level equal to or higher than the threshold value α), the situation where the regenerative power becomes larger than the threshold value α when the vehicle 1 decelerates (that is, only with the regenerative power). A situation where the SOC can be recovered early) may occur. Nevertheless, if the engine 10 is always operated, the fuel consumption of the engine 10 increases more than necessary, and the fuel consumption may deteriorate.

  Therefore, ECU 100 according to the present embodiment permits intermittent operation of engine 10 based on the requested regeneration level received from regeneration level adjusting device 3 during the SOC recovery mode (that is, permits the engine 10 to stop). ) Or the intermittent operation of the engine 10 (that is, the engine 10 is always operated by prohibiting the stop of the engine 10).

  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 S10, ECU 100 determines whether or not the SOC recovery mode is being executed. If the SOC recovery mode is not being executed (NO in S10), ECU 100 ends the process.

  If the SOC recovery mode is being executed (YES in S10), ECU 100 determines in S11 whether second MG 30 is performing regenerative power generation.

  If second MG 30 is performing regenerative power generation (YES in S11), ECU 100 determines in S12 that the required regeneration level received from regeneration level adjustment device 3 is greater than a predetermined level (a level equal to or greater than threshold value α). Determine whether or not.

  When second MG 30 is not performing regenerative power generation (NO in S11), or when the required regenerative level is lower than a predetermined level (NO in S12), the regenerative power is less than threshold value α, so the SOC is recovered early. In order to achieve this, engine generated power is required. Therefore, ECU 100 prohibits intermittent operation of engine 10 in S13. That is, the ECU 100 prohibits the stop of the engine 10 and always operates the engine 10.

  At this time, the ECU 100 causes the engine 10 to output a value obtained by adding the required charging amount (driving force used for generating engine generated power) to the driving force requested by the user. The required charge amount is determined based on the thermal efficiency distribution of the engine 10 and the acceptable power of the battery 70 within a range where the engine generated power is larger than the threshold value α. For example, when the user's requested driving force is small with respect to the engine output at which the thermal efficiency is maximized (hereinafter referred to as “fuel consumption maximum output”), the output of the engine 10 (the sum of the requested driving force and the requested charge amount) The thermal efficiency of the engine 10 is improved by increasing the required charge amount until the maximum output is reached. However, from the viewpoint of protection of the battery 60, the upper limit of the required charge amount is limited to a range less than the acceptable power of the battery 70.

  On the other hand, when the required regeneration level is greater than the predetermined level (YES in S12), a situation may occur in which the regenerative power becomes greater than threshold value α when vehicle 1 decelerates. Therefore, ECU 100 allows intermittent operation of engine 10 (that is, permits stop of engine 10) in S14 to S16.

  Specifically, in S14, ECU 100 determines whether or not the actual regenerative power is larger than threshold value α. If the actual regenerative power is larger than threshold value α (YES in S14), since the SOC can be recovered early with only the regenerative power, ECU 100 stops engine 10 in S15. On the other hand, when the actual regenerative power is smaller than threshold value α (NO in S14), the engine 10 is operated in S16 because engine generated power is required to recover the SOC at an early stage. At this time, the ECU 100 controls the output of the engine 10 as in S13.

  FIG. 3 is a diagram illustrating an example of a change in battery charging power (power input to the battery 60) during execution of the SOC recovery mode.

  A case is assumed in which the user is shifted to the SOC recovery mode by operating the SOC recovery switch 2 at time t1 during traveling at a constant speed.

  During the period from time t1 to time t2, since the vehicle is running at a constant speed and regenerative power generation is not performed, intermittent operation of the engine 10 is prohibited regardless of the required regeneration level. Therefore, engine 10 is operated and battery 60 is charged with engine power that is larger than threshold value α.

  At time t2 when the vehicle 1 starts decelerating and regenerative power generation starts, the required regenerative level exceeds a predetermined level, and therefore a situation in which the regenerative power becomes larger than the threshold value α in the future may occur. Therefore, intermittent operation of the engine 10 is allowed.

  Specifically, in the period from time t2 to time t3, since the regenerative power is still smaller than the threshold value α, the operation of the engine 10 is continued. Therefore, in this period, the battery 60 is charged with both the electric power generated by the engine and the regenerative charging.

  In the period from time t3 to time t4, the regenerative electric power exceeds the threshold value α and the SOC can be recovered early with only the regenerative electric power, so the engine 10 is stopped. Therefore, during this period, the battery 60 is charged only with regenerative power.

  When the regenerative power falls below the threshold value α again at time t4, the engine 10 is restarted, and the battery 60 is charged with both the power generated by the engine and the regenerative charge.

  After time t5, the regenerative electric power becomes 0 with the stop of the vehicle 1, so that the intermittent operation of the engine 10 is prohibited again. Therefore, the operation of the engine 10 is continued even after time t5, and the charging of the battery 60 is continued with the engine generated power.

  As described above, the ECU 100 operates the engine 10 intermittently when regenerative power generation is being performed and the required regeneration level exceeds a predetermined level during the SOC recovery mode (period from time t2 to time t5). The battery charging power is maintained at a value larger than the threshold value α while allowing the charging to be performed. Therefore, the SOC can be recovered early while suppressing the fuel consumption of the engine 10.

  As described above, the ECU 100 according to the present embodiment does not uniformly prohibit the stop of the engine 10 during execution of the SOC recovery mode, but stops the engine 10 when the required regeneration level is higher than a predetermined level. Is acceptable. Therefore, it is possible to quickly recover the SOC while suppressing the fuel consumption of the engine 10.

  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 SOC recovery switch, 3 regeneration level adjusting device, 10 engine, 20 1st MG, 30 2nd MG, 40 power split device, 50 PCU, 60 battery, 80 drive wheel, 100 ECU.

Claims (3)

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,
It is electrically connected to the motor generator and is charged by at least one of engine generated power generated by the motor generator using the power of the engine and regenerative power generated by the motor generator using kinetic energy of the vehicle. Battery,
A regeneration level setting unit for setting the required level of the regenerative power according to a user operation;
A controller that determines whether or not to stop the engine based on a required level of the regenerative power set by the regenerative level setting unit during the execution of the recovery mode for recovering the storage amount of the battery; A vehicle equipped with.   The control unit does not allow the engine to be stopped when the recovery mode is being executed and the required level of the regenerative power is lower than a predetermined level, while the recovery mode is being executed and the regenerative power is requested. The vehicle according to claim 1, wherein the engine is allowed to stop when the level is higher than the predetermined level. The recovery mode is a mode for recovering the storage amount of the battery by charging the battery with power larger than a predetermined power,
The control unit operates the engine when the actual regenerative power is lower than the predetermined power when the recovery mode is being executed and the required level of the regenerative power is higher than the predetermined level. The vehicle according to claim 2, wherein the engine is stopped when the regenerative power is greater than the predetermined power.

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