JP2012086643A - Device and method for control of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid vehicle control device that can improve synthetic efficiency of energy according to operation or a condition of components concerning driving of a vehicle.SOLUTION: The vehicle control device includes: a power generation part which has an internal combustion engine and a generator which generates electric power by operation of the internal combustion engine; an energy storage part which has a capacitor which supplies power to an electric motor which is a driving source of the vehicle; and a consumption part which has the electric motor driven by power supply from at least either the energy storage part or the generator. The vehicle control device controls the internal combustion engine to operate at the operating point by including: a means to derive a condition of the capacitor; a means to derive output required for the consumption part from efficiency of the consumption part drawn based on the condition of the electric motor and the output required for the electric motor based on the condition of a gas pedal opening and electric motor according to gas pedal operation in the hybrid vehicle; a means to derive output of the optimal power generation part corresponding to the output required for the consumption part according to the condition of the capacitor; and a means to derive an operating point of the internal combustion engine corresponding to the output of the optimal power generation part.

Description

  The present invention relates to a control device and a control method for a hybrid vehicle.

  FIG. 14 is an overall configuration diagram of a hybrid electric vehicle disclosed in Patent Document 1. As shown in FIG. The control device 17 shown in FIG. 14 calculates the APU energy loss amount Pla from the operating state of the APU 13 including the engine 11 and the generator 12, and calculates the battery energy loss amount Plb from the charge / discharge state of the battery 14. The operation of the engine 11 is controlled so that the difference between the APU energy output amount Pa and the battery energy loss amount Plb with respect to the sum of the energy output amount Pa and the APU energy loss amount Pla is maximized. For this reason, it is possible to generate electric power suitable for the traveling state of the vehicle 10 and supply it to the motor 15, improve the power supply efficiency, and reduce the fuel cost and exhaust gas by improving the fuel consumption in the engine 11. Can be achieved.

JP 09-093716 A

  In the vehicle 10 of Patent Document 1 described above, the electric power supplied to the motor 15 is generated when the engine 11 drives the generator 12. As a method for operating the engine in such a vehicle, a plurality of methods such as a fixed point operation and an output following operation can be considered. However, the control device 17 of Patent Document 1 does not perform control for improving the power supply efficiency in accordance with the operation method of the engine 11.

  Further, the control device 17 does not perform control in consideration of the efficiency of the motor 15 that is a drive source of the vehicle 10.

  Furthermore, the battery energy loss amount Plb, which is a parameter used when controlling the operation of the engine 11, is the sum of the loss amount calculated from the charging efficiency in the battery 14 and the discharge loss amount, but the actual loss amount is Depends on battery type, operating conditions, temperature, etc. For example, since the internal resistance of the battery increases in a low temperature environment, the actual amount of loss increases. However, the control device 17 of Patent Document 1 does not consider the change in the battery energy loss amount Plb according to the state of the battery 14 except for the charge / discharge state.

  The objective of this invention is providing the control apparatus and control method of a hybrid vehicle which can improve total energy efficiency according to operation | movement or the state of the component which concerns on driving of a vehicle.

  In order to solve the above-described problems and achieve the object, a hybrid vehicle control device according to a first aspect of the present invention includes an internal combustion engine (for example, the internal combustion engine 109 in the embodiment) and an operation of the internal combustion engine. A power generation unit (for example, the power generation unit 123 in the embodiment) having a power generator (for example, the power generator 111 in the embodiment) and a capacitor (for example, a power supply that supplies electric power to an electric motor that is a drive source of the hybrid vehicle) In addition, a power storage unit (for example, power storage unit 121 in the embodiment) having a power storage device 101 in the embodiment, and an electric motor (for example, implementation) driven by power supply from at least one of the power storage unit and the generator A control unit for the hybrid vehicle (e.g., in the embodiment) having a consumption unit (e.g., the consumption unit 125 in the embodiment) having an electric motor 107) in the form A capacitor state deriving unit (e.g., an internal resistance deriving unit 201 in the embodiment) for deriving the state of the capacitor, and the efficiency of the consumption unit derived based on the state of the electric motor. In addition, a consumption part necessary output deriving unit (for example, deriving an output requested by the consumption unit from an output requested by the electric motor based on an accelerator pedal opening corresponding to an accelerator operation in the hybrid vehicle and a state of the electric motor (for example, The consumption part efficiency deriving part 203 in the embodiment, the motor required output calculating part 205 and the consumption part required output calculating part 207), and corresponding to the output requested by the consumption part according to the state of the battery An optimal power generation unit output deriving unit (for example, the optimal power generation unit output deriving unit 209 in the embodiment) for deriving the optimal output of the power generation unit; An internal combustion engine operating point deriving unit (for example, an internal combustion engine operating point deriving unit 213 in the embodiment) for deriving an operating point of the internal combustion engine corresponding to the output of the power generation unit, and the internal combustion engine operating point deriving unit The internal combustion engine is controlled to operate at an operating point derived from the above.

  Furthermore, in the hybrid vehicle control device according to the second aspect of the present invention, the operation mode of the internal combustion engine is fixed according to the magnitude relationship between the optimum output of the power generation unit and the output required of the consumption unit. An operation mode determination unit that determines one of a fixed-point operation mode that is operated at a rotation speed and a torque and an output follow-up operation mode that is operated at a required rotation speed and torque according to a required output from a driver of the hybrid vehicle (For example, the operation mode determination unit 211 in the embodiment), and the internal combustion engine operation point deriving unit corresponds to the optimum output of the power generation unit according to the operation mode determined by the operation mode determination unit The operating point of the internal combustion engine is derived.

  Furthermore, in the hybrid vehicle control device according to claim 3, the output of the optimum power generation unit derived by the optimum power generation unit output deriving unit is greater than the output required for the consumption unit. It is characterized by being the output of the power generation unit that maximizes the overall vehicle efficiency of the power storage unit, the power generation unit, and the consumption unit for each state.

  Furthermore, in the hybrid vehicle control device according to a fourth aspect of the present invention, the power storage unit includes the power storage unit, and a converter that performs step-up or step-down between the power storage unit, the power generation unit, and the consumption unit (for example, implementation) The overall vehicle efficiency includes, as one of the parameters, the charge / discharge efficiency based on the converter efficiency according to the target voltage of the converter and the battery efficiency according to the state of the battery. It is characterized by that.

  Furthermore, in the hybrid vehicle control method according to the fifth aspect of the present invention, an internal combustion engine (for example, the internal combustion engine 109 in the embodiment) and a generator that generates electric power by the operation of the internal combustion engine (for example, in the embodiment) A power storage unit (for example, power generation unit 123 in the embodiment) having a power generator 111) and a power storage unit (for example, power storage unit 101 in the embodiment) that supplies power to an electric motor that is a drive source of the hybrid vehicle. Consumption unit (for example, electric storage unit 121 in the embodiment) and an electric motor (for example, electric motor 107 in the embodiment) driven by power supply from at least one of the electric storage unit and the generator , A consumption unit 125) in the embodiment, and a method of controlling the hybrid vehicle, wherein the state of the battery is derived and based on the state of the electric motor From the output required for the electric motor based on the efficiency of the consumption unit derived as described above, and the accelerator pedal opening corresponding to the accelerator operation in the hybrid vehicle and the state of the electric motor, the output required for the consumption unit is obtained. Deriving and deriving an optimal output of the power generation unit corresponding to the output requested of the consumption unit according to the state of the capacitor, and operating point of the internal combustion engine corresponding to the optimal output of the power generation unit And controlling the internal combustion engine that operates at the derived operating point.

  According to the hybrid vehicle control device of the first to fourth aspects of the invention and the hybrid vehicle control method of the fifth aspect of the invention, the overall control is performed according to the operation or state of the components related to the driving of the vehicle. Energy efficiency can be improved.

  According to the hybrid vehicle control device of the second aspect of the present invention, even when the operating point of the internal combustion engine varies depending on the operation mode, the overall energy efficiency can be improved.

  According to the hybrid vehicle control device of the third aspect of the invention, it is possible to improve the overall vehicle efficiency combining the efficiency of the power storage unit, the power generation unit, and the consumption unit.

  According to the hybrid vehicle control device of the invention described in claim 4, the efficiency of the power storage unit can be derived more accurately.

Block diagram showing the internal configuration of a series-type HEV The block diagram which shows the internal structure of management ECU119 The figure which shows the input-output relationship and efficiency of the electrical storage part 121, the electric power generation part 123, and the consumption part 125. The flowchart which shows the derivation | leading-out method of the parameter for controlling the internal combustion engine 109 by management ECU119. The figure which shows the battery temperature-internal resistance map The figure which shows a battery current-battery voltage map Diagram showing consumption efficiency map Diagram showing optimum power output map The figure which shows the relationship between the electric power generation part efficiency g and the electric power generation part output G Diagram showing battery efficiency map Diagram showing converter efficiency map Diagram showing target voltage map Figure showing the maximum efficiency point map Overall configuration diagram of hybrid electric vehicle disclosed in Patent Document 1

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiments described below, the control device according to the present invention is mounted on a series-type HEV (Hybrid Electrical Vehicle). The series-type HEV includes an electric motor, an internal combustion engine, and a generator, and travels by using the power of an electric motor that is mainly driven by a capacitor as a power source. The internal combustion engine is used only for power generation, and the electric power generated by the generator by the power of the internal combustion engine is supplied to the electric motor or charged in the capacitor.

  The series-type HEV performs “EV traveling” or “series traveling”. In “EV traveling”, HEV travels by the driving force of an electric motor that is driven by power supply from a capacitor. At this time, the internal combustion engine is not driven. Further, in “series travel”, the HEV travels by the driving force of an electric motor that is driven by the supply of power from both the power storage device and the generator or the supply of power from only the generator. At this time, the internal combustion engine is driven for power generation in the generator.

  FIG. 1 is a block diagram showing the internal configuration of a series-type HEV. As shown in FIG. 1, a series-type HEV includes a battery (BATT) 101, a converter (CONV) 103, a first inverter (first INV) 105, an electric motor (MOT) 107, and an internal combustion engine (ENG) 109. And a generator (GEN) 111, a second inverter (second INV) 113, a gear box (hereinafter simply referred to as “gear”) 115, and a management ECU (MG ECU) 119.

  The storage battery 101 has a plurality of storage cells connected in series, and supplies a high voltage of, for example, 100 to 200V. The storage cell is, for example, a lithium ion battery or a nickel metal hydride battery. Converter 103 boosts or steps down the DC output voltage of battery 101 while maintaining DC. The first inverter 105 converts a DC voltage into an AC voltage and supplies a three-phase current to the electric motor 107. Further, the first inverter 105 converts the AC voltage input during the regenerative operation of the electric motor 107 into a DC voltage and charges the battery 101.

  The electric motor 107 generates power for running the HEV. Torque generated by the electric motor 107 is transmitted to the drive shaft 151 via the gear 115. Note that the rotor of the electric motor 107 is directly connected to the gear 115. In addition, the electric motor 107 operates as a generator during regenerative braking, and the electric power generated by the electric motor 107 is charged in the capacitor 101. The internal combustion engine 109 is used to drive the generator 111 when the HEV travels in series. The internal combustion engine 109 is directly connected to the rotor of the generator 111.

  The generator 111 is driven by the power of the internal combustion engine 109 to generate electric power. The electric power generated by the generator 111 is charged in the battery 101 or supplied to the electric motor 107. The second inverter 113 converts the AC voltage generated by the generator 111 into a DC voltage. The electric power converted by the second inverter 113 is charged in the battery 101 or supplied to the electric motor 107 via the first inverter 105.

  The gear 115 is a one-stage fixed gear corresponding to, for example, the fifth speed. Therefore, the gear 115 converts the driving force from the electric motor 107 into a rotation speed and torque at a specific gear ratio, and transmits them to the drive shaft 151.

  The management ECU 119 performs control of the internal combustion engine 109 and the electric motor 107 and the like. Note that the operation modes of the internal combustion engine 109 controlled by the management ECU 119 include a fixed point operation mode and an output follow-up operation mode. In the fixed point operation mode, the internal combustion engine 109 is operated at a constant rotational speed and torque with the best fuel efficiency. On the other hand, in the output follow-up operation mode, the internal combustion engine 109 is operated at a necessary rotation speed and torque according to the required output. In addition, the management ECU 119 performs switching control of the switching elements that constitute the first inverter 105 and the second inverter 113, respectively.

  Further, as shown by a dotted line in FIG. 1, the management ECU 119 includes information indicating the temperature of the battery 101, information indicating the rotation speed and torque of the electric motor 107, information indicating the rotation speed and torque of the generator 111, and Information indicating the accelerator pedal opening (AP opening) corresponding to the accelerator operation of the HEV driver is acquired. These pieces of information are sent to the management ECU 119 from a sensor (not shown) that detects each parameter. The management ECU 119 derives a target torque (target engine torque) and a target rotational speed (target engine rotational speed) of the internal combustion engine 109 based on the acquired information, and an operation indicated by the target engine torque and the target engine rotational speed. The internal combustion engine 109 and the second inverter 113 are controlled to operate at a point.

  FIG. 2 is a block diagram showing an internal configuration of the management ECU 119. As shown in FIG. 2, the management ECU 119 includes an internal resistance deriving unit 201, a consumption unit efficiency deriving unit 203, a motor required output calculating unit 205, a consumption unit required output calculating unit 207, and an optimum power generation unit output deriving unit 209. And an operation mode determination unit 211 and an internal combustion engine operation point deriving unit 213.

  Hereinafter, the operation of each component of the management ECU 119 and a method for deriving parameters (target engine torque and target engine speed) for controlling the internal combustion engine 109 by the management ECU 119 will be described with reference to FIGS. 2 and 3 to 13. To explain. In the following description, as shown in FIG. 3, converter 103 and battery 101 are collectively referred to as “power storage unit 121”. Further, the internal combustion engine 109, the generator 111, and the second inverter 113 are collectively referred to as a “power generation unit 123”. Further, the first inverter 105 and the electric motor 107 are collectively referred to as a “consumption unit 125”.

  FIG. 4 is a flowchart showing a parameter derivation method for controlling the internal combustion engine 109 by the management ECU 119. 5 to 13 show maps used by the management ECU 119 when deriving parameters for controlling the internal combustion engine 109. These maps are stored in a memory provided inside the management ECU 119 or an external memory accessible by the management ECU 119.

  As shown in FIG. 4, the internal resistance deriving unit 201 derives the internal resistance R of the battery 101 based on the temperature of the battery 101 (battery temperature T) and the battery temperature-internal resistance map shown in FIG. 5 (step S101). ). In addition, when the remaining capacity (SOC: State of Charge) and the output voltage (battery voltage V) of the capacitor 101 are obtained from the capacitor 101, the internal resistance deriving unit 201 is based on the battery current-battery voltage map shown in FIG. Alternatively, the output current (battery current I) of the battery 101 may be derived, and the internal resistance R may be calculated from the calculation formula of internal resistance R = battery voltage V / battery current I. Alternatively, when the output current (battery current I) of the battery 101 and the output voltage (battery voltage V) of the battery 101 are obtained, the internal resistance deriving unit 201 uses the calculation formula of internal resistance R = battery voltage V / battery current I. The internal resistance R may be calculated. In these cases, a change in the internal resistance R accompanying the aging of the battery 101 can be considered.

  Next, the consumption unit efficiency deriving unit 203 determines the efficiency of the consumption unit 125 based on the rotation speed (motor rotation speed NE) and torque (motor torque Tr) of the electric motor 107 and the consumption unit efficiency map shown in FIG. M (hereinafter referred to as “consumer efficiency”) is derived (step S103). The consumption unit efficiency m is the total efficiency of the second inverter 113 and the electric motor 107 that constitute the consumption unit 125.

  Next, the motor required output calculation unit 205 calculates an output (hereinafter referred to as “motor required output”) Pm requested to the electric motor 107 based on the AP opening, the motor rotational speed NE, and the motor torque Tr (step S104). ).

Next, the consumption unit required output calculation unit 207 calculates the output requested by the consumption unit 125 (hereinafter referred to as “consumption unit required output”) from the following equation (1) based on the motor required output Pm and the consumption unit efficiency m. Mr is calculated (step S105).
Mr = Pm / m (1)

  Next, the optimal power generation unit output deriving unit 209 generates power based on the consumption unit required output Mr, the internal resistance R of the battery 101 derived by the internal resistance deriving unit 201 in step S101, and the optimal power generation output map shown in FIG. The optimum output of the unit 123 (hereinafter referred to as “optimum power generation unit output”) Go is derived (step S107).

  As shown in FIG. 9, the power generation unit efficiency g, which is the overall efficiency of the internal combustion engine 109, the power generator 111, and the second inverter 113 constituting the power generation unit 123, is the output of the power generation unit 123 (hereinafter referred to as “power generation unit output”). It depends on G). Therefore, the optimum power generation output map shown in FIG. 8 is the power generation unit output G that maximizes the total vehicle efficiency including the efficiency of the power storage unit 121, the power generation unit 123, and the consumption unit 125 for each internal resistance R of the battery 101. Is calculated in a range of “power generation unit output G ≧ consumption unit required output Mr”. In the optimal power generation output map created in this way, the optimal power generation unit output Go is higher when the consumption unit required output Mr is less than a predetermined value, and the higher the internal resistance R of the battery 101, the higher the consumption unit required output Mr. When the value is equal to or greater than a predetermined value, it is the same regardless of the internal resistance R.

The vehicle overall efficiency is expressed by the following equation (2).
Total vehicle efficiency = g × {(1−B) + B × b} × m (2)
However,
g: power generation unit efficiency m: consumption unit efficiency b: charge / discharge efficiency (= battery efficiency × converter efficiency)
B (ratio through power storage unit 121) = 1−Mr / G (where M: consumption unit required output, G: power generation unit output)

  The battery efficiency and the converter efficiency, which are parameters necessary for calculating the charge / discharge efficiency b, are obtained from the battery efficiency map shown in FIG. 10 and the converter efficiency map shown in FIG. 11, respectively. As shown in FIG. 10, the battery efficiency is obtained according to the internal resistance R of the battery 101. Further, as shown in FIG. 11, the converter efficiency varies depending on the target voltage. The target voltage is obtained based on the rotation speed (motor rotation speed NE) and torque (motor torque Tr) of the electric motor 107, and the target voltage map shown in FIG.

  After step S107, the operation mode determination unit 211 calculates the optimum power generation unit output Go derived by the optimal power generation unit output deriving unit 209 in step S107 and the consumption unit required output Mr calculated by the motor request output calculation unit 205 in step S104. The magnitude relation is compared (step S109). As a result of the comparison performed in step S109, when the optimum power generation unit output Go is larger than the consumption unit required output Mr (Go> Mr), the process proceeds to step S111, and the operation mode determination unit 211 sets the internal combustion engine 109 in the fixed point operation mode. Decide to control. On the other hand, when the optimal power generation unit output Go is equal to or less than the consumption unit required output Mr (Go ≦ Mr), the process proceeds to step S113, and the operation mode determination unit 211 determines to control the internal combustion engine 109 in the output follow-up operation mode.

  After step S111 and step S113, the internal combustion engine operating point deriving unit 213, based on the optimal power generation unit output Go derived by the optimal power generation unit output deriving unit 209 in step S107 and the power generation unit maximum efficiency point map shown in FIG. A target torque (target engine torque) and a target rotational speed (target engine rotational speed) of the internal combustion engine 109 are derived (step S115). The target engine torque and target engine speed derived by the internal combustion engine operating point deriving unit 213 in step S115 are the internal combustion engines in which the power generation unit efficiency g is maximized when the internal combustion engine 109 is controlled in the fixed point operation mode or the output following operation mode. The torque and rotational speed at the operating point of the engine 109 are shown.

  As described above, in the present embodiment, after the management ECU 119 derives the optimal power generation unit output Go using the optimal power generation output map based on the internal resistance R of the battery 101, the consumption unit efficiency m, and the motor required output Pm. Then, the operating point of the internal combustion engine 109 is derived according to the optimum power generation unit output Go. Thus, in the process until the operating point of the internal combustion engine 109 is derived, the internal resistance R, the consumption unit efficiency m, and the optimum power generation unit output Go of the battery 101 are considered. The optimum power generation output map is a map set based on the power generation unit efficiency g, the consumption unit efficiency m, and the charge / discharge efficiency b. Therefore, when the internal combustion engine 109 is operated at the operating point, the overall vehicle efficiency combining the efficiency of the power storage unit 121, the power generation unit 123, and the consumption unit 125 is the best.

101 Battery (BATT)
103 Converter (CONV)
105 1st inverter (1st INV)
107 Electric motor (MOT)
109 Internal combustion engine (ENG)
111 Generator (GEN)
113 Second inverter (second INV)
115 Gearbox 119 Management ECU (MG ECU)
201 Internal Resistance Deriving Unit 203 Consumption Unit Efficiency Deriving Unit 205 Motor Required Output Calculation Unit 207 Consumption Unit Required Output Calculation Unit 209 Optimal Power Generation Unit Output Deriving Unit 211 Operation Mode Determination Unit 213 Internal Combustion Engine Operating Point Deriving Unit 121 Power Storage Unit 123 Power Generation Unit 125 Consumption Department

Claims (5)

A power generation unit having an internal combustion engine and a generator that generates power by operation of the internal combustion engine;
A power storage unit having a capacitor for supplying electric power to an electric motor that is a drive source of the hybrid vehicle;
A control unit for the hybrid vehicle comprising: a consumption unit having an electric motor driven by power supply from at least one of the power storage unit and the generator;
A capacitor state deriving unit for deriving a state of the capacitor;
From the efficiency of the consumption unit derived based on the state of the motor, the accelerator pedal opening according to the accelerator operation in the hybrid vehicle, and the output required for the motor based on the state of the motor, the consumption unit A required consumption deriving unit for deriving the output requested by
An optimum power generation unit output deriving unit for deriving an optimum output of the power generation unit corresponding to the output requested of the consumption unit according to the state of the battery;
An internal combustion engine operating point deriving unit for deriving an operating point of the internal combustion engine corresponding to the optimal output of the power generation unit,
A control apparatus for a hybrid vehicle, wherein the internal combustion engine is controlled to operate at an operating point derived by the internal combustion engine operating point deriving unit. The hybrid vehicle control device according to claim 1,
Depending on the magnitude relationship between the optimum output of the power generation unit and the output required of the consumption unit, the operation mode of the internal combustion engine is a fixed point operation mode in which the engine is operated at a constant rotation speed and torque, and the hybrid vehicle. An operation mode determination unit that determines any of the output follow-up operation modes that are operated at the required rotation speed and torque according to the required output from the driver,
The internal combustion engine operating point deriving unit derives an operating point of the internal combustion engine corresponding to the optimum output of the power generation unit according to the operation mode determined by the operation mode determining unit. Control device. The hybrid vehicle control device according to claim 1 or 2,
The output of the optimal power generation unit derived by the optimal power generation unit output deriving unit is the output of the power storage unit, the power generation unit, and the consumption unit for each state of the battery with respect to the output requested of the consumption unit. A hybrid vehicle control device characterized by being the output of the power generation unit that maximizes the overall vehicle efficiency combined with each efficiency. A control device for a hybrid vehicle according to claim 3,
The power storage unit includes the power storage unit, and a converter that performs step-up or step-down between the power storage unit and the power generation unit and the consumption unit,
The vehicle overall efficiency includes, as one of parameters, a converter efficiency according to a target voltage of the converter and a charge / discharge efficiency based on a battery efficiency according to a state of the battery as a parameter. A power generation unit having an internal combustion engine and a generator that generates power by operation of the internal combustion engine;
A power storage unit having a capacitor for supplying electric power to an electric motor that is a drive source of the hybrid vehicle;
A control unit for the hybrid vehicle comprising: a consumption unit having an electric motor driven by power supply from at least one of the power storage unit and the generator;
Deriving the state of the capacitor,
From the efficiency of the consumption unit derived based on the state of the motor, the accelerator pedal opening according to the accelerator operation in the hybrid vehicle, and the output required for the motor based on the state of the motor, the consumption unit To derive the requested output
Depending on the state of the battery, the optimal output of the power generation unit corresponding to the output requested of the consumption unit is derived,
Deriving the operating point of the internal combustion engine corresponding to the optimal output of the power generation unit,
A control method for a hybrid vehicle, comprising: controlling the internal combustion engine that operates at the derived operating point.

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