KR20210053380A - Apparatus for controlling hybrid vehciel having electric supercharger and method using the same - Google Patents

Abstract

The present invention provides a control apparatus of a hybrid vehicle which can minimize fuel efficiency loss while satisfying the request torque of a driver if the outside temperature of a vehicle is very high or low. According to an embodiment of the present invention, the control apparatus of a hybrid vehicle comprises: an engine which combusts fuel to generate power; a drive motor which assists the power of the engine and selectively operates as a generator to generate electric energy; a clutch provided between the engine and the drive motor; a battery which supplies electric energy to the drive motor or charges the electric energy generated by the drive motor; a direct current converter which converts a direct current outputted from the battery; an electrically-driven supercharger which supplies supercharging air to the engine; and a controller which determines an optimal air volume for maximizing system efficiency based on an output limit value of the drive motor in accordance with the temperature of the battery or the drive motor, and determines drive motor power outputted by the drive motor and engine power outputted by the engine based on the optimal air volume.

Description

A control device for a hybrid vehicle equipped with an electric supercharger and a control method using the same {APPARATUS FOR CONTROLLING HYBRID VEHCIEL HAVING ELECTRIC SUPERCHARGER AND METHOD USING THE SAME}

The present invention relates to a control apparatus for a hybrid vehicle equipped with an electric supercharger and a control method using the same, and more particularly, in a hybrid vehicle equipped with an electric supercharger, the output of the drive motor is limited according to the temperature of the drive motor or battery. When it becomes possible, the present invention relates to a control apparatus for a hybrid vehicle including an electric supercharger for determining an operating point of an engine, and a control method using the same.

A hybrid vehicle is a vehicle that uses two or more power sources, and generally refers to a hybrid electric vehicle that is driven using an engine and a motor. Hybrid electric vehicles can form various structures using two or more power sources consisting of an engine and a drive motor.

In general, a hybrid electric vehicle uses a transmission mounted electric device (TMED) type power train in which a drive motor, a transmission 80, and a drive shaft are connected in series.

In addition, a clutch 60 is provided between the engine and the motor, and according to whether the clutch 60 is engaged, the hybrid electric vehicle is operated in an electric vehicle (EV) mode or a hybrid electric vehicle (HEV) mode. The EV mode is a mode in which the vehicle is driven only by the driving force of the driving motor, and the HEV mode is a mode in which the vehicle is driven by the driving force of the driving motor and the engine.

Since the drive motor and battery provided in the hybrid vehicle react sensitively to the external temperature, when the vehicle travels in an area where the external temperature is very high or very low, frequent charging and discharging of the battery is limited, resulting in a decrease in the output of the driving motor. . Therefore, in this case, it is difficult to implement the power performance required by the driver.

The matters described in this background are prepared to enhance an understanding of the background of the invention, and may include matters other than the prior art already known to those of ordinary skill in the field to which this technology belongs.

The present invention is to solve the above-described problems, and to provide a control apparatus and method for a hybrid vehicle capable of minimizing fuel economy loss while meeting a driver's required torque when the external temperature of the vehicle is very high or low. The purpose.

A control apparatus for a hybrid vehicle according to an embodiment of the present invention for achieving the above object includes an engine for generating power by burning fuel; A driving motor that assists the power of the engine and selectively operates as a generator to generate electric energy; A clutch provided between the engine and the drive motor; A battery that supplies electric energy to the drive motor or charges electric energy generated by the drive motor; A DC converter for converting DC output from the battery; An electric supercharger supplying supercharged air to the engine; And determining an optimum amount of air at which system efficiency is maximized based on an output limit value of the driving motor according to the temperature of the driving motor or the battery, and the engine power output from the engine and the driving motor based on the optimum air amount. It may include; a controller that determines the output drive motor power.

The system efficiency is the power required by the driver, the amount of fuel supplied to the engine, the low heat value of the fuel, the power consumed by the electric supercharger, the power consumed by the DC converter, the engine power output from the engine, and the driving motor. Efficiency, and power transfer efficiency.

의 수학식으로부터 결정되고, 여기서, P_dirver는 운전자의 요구 파워, M_fuel은 상기 엔진으로 공급되는 연료 유량, LHV는 연료의 저위 발열량, P_esc는 전동식 슈퍼차저에서 소모되는 전력, P_LDC는 직류 변환기에서 소모되는 전력, P_eng는 엔진 파워, η_mot는 구동 모터의 효율, 및 η_tran는 전력 전달 효율일 수 있다.The system efficiency is

Where P _dirver is the driver's required power, M _fuel is the fuel flow rate supplied to the engine, LHV is the low heating value of the fuel, P _esc is the power consumed in the electric supercharger, and P _LDC is the direct current. Power consumed by the converter, P _eng may be engine power, η _mot may be the efficiency of the driving motor, and η _tran may be the power transfer efficiency.

According to another embodiment of the present invention, a method for controlling a hybrid vehicle includes receiving, by a controller, driving information including a temperature of a driving motor, a temperature of a battery, a driver's required power, and an engine speed; By the controller, when the temperature of the driving motor or the temperature of the battery is out of a set temperature range, the system efficiency is maximized based on an output limit value of the driving motor or the driving motor determined according to the temperature of the battery. Determining the amount of air; Determining, by the controller, an engine torque output from the engine from the optimum air amount; And determining an output torque of the drive motor to meet the driver's required torque from the engine torque.

The system efficiency is the power required by the driver, the amount of fuel supplied to the engine, the low heat value of the fuel, the power consumed by the electric supercharger, the power output from the DC converter, the engine power output from the engine, and the driving motor. It can be determined from the efficiency, and the power transfer efficiency.

의 수학식으로부터 결정되고, 여기서, P_dirver는 운전자의 요구 파워, M_fuel은 상기 엔진으로 공급되는 연료량, LHV는 연료의 저위 발열량, P_esc는 전동식 슈퍼차저에서 소모되는 전력, P_LDC는 직류 변환기에서 소모되는 전력, P_eng는 엔진 파워, η_mot는 구동 모터의 효율, 및 η_tran는 전력 전달 효율일 수 있다.The system efficiency is

Where P _dirver is the driver's required power, M _fuel is the amount of fuel supplied to the engine, LHV is the low heat value of the fuel, P _esc is the power consumed in the electric supercharger, and P _LDC is the DC converter. The power consumed at, P _eng is the engine power, η _mot is the efficiency of the driving motor, and η _tran is the power transfer efficiency.

According to the apparatus and method for controlling a hybrid vehicle according to an embodiment of the present invention as described above, when the external temperature of the vehicle is very high or low, it is possible to minimize fuel economy loss while satisfying the driver's required torque.

These drawings are for reference only in describing exemplary embodiments of the present invention, and thus the technical idea of the present invention should not be construed as being limited to the accompanying drawings.
1 is a conceptual diagram showing the configuration of a control apparatus for a hybrid vehicle according to an embodiment of the present invention.
2 is a conceptual diagram showing a relationship between an engine of a hybrid vehicle and an electric supercharger according to an embodiment of the present invention.]
3 is a block diagram showing the configuration of a control apparatus for a hybrid vehicle according to an embodiment of the present invention.
4 is a flowchart illustrating a method of controlling a hybrid vehicle according to an embodiment of the present invention.
5 is a view showing an operating point of an engine according to an embodiment of the present invention.

With reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

In order to clearly describe the present invention, parts irrelevant to the description have been omitted, and the same reference numerals are attached to the same or similar components throughout the specification.

In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, so the present invention is not necessarily limited to those shown in the drawings, and the thickness is enlarged to clearly express various parts and regions. I got it.

Hereinafter, an apparatus for controlling a hybrid vehicle according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram showing the configuration of a control apparatus for a hybrid vehicle according to an embodiment of the present invention. 2 is a conceptual diagram showing a relationship between an engine of a hybrid vehicle and an electric supercharger according to an embodiment of the present invention.

1 to 4, the hybrid vehicle to which the control device of the hybrid vehicle according to the embodiment of the present invention is applied includes an engine 10, an HSG 40, a drive motor 50, a clutch 60, A battery 70, a low-voltage DC/DC converter (LDC), an electric supercharger 30, an accelerator pedal sensor 100, and a controller 90 may be included.

The driving information sensing unit 100 detects driving information including the temperature of the battery 70, the temperature of the driving motor 50, the engine speed, and the driver's required torque (or required power), and the detected driving information is a controller. It is sent to (90).

To this end, the driving information sensing unit is a temperature sensor that detects the temperature of the battery 70, another temperature sensor that detects the temperature of the driving motor 50, a speed sensor that detects the engine speed, and the driver's required torque (or required power). It may include an accelerator pedal sensor 100 or the like for determining ).

The driving motor 50 is operated using electric energy charged in the battery 70, and the electric energy generated by the driving motor 50 and the HSG 40 is charged in the battery 70.

The electric supercharger 30 is for supplying supercharged air to the combustion chamber of the engine 10 and includes a motor 31 and an electric compressor 33. The electric compressor 33 is operated by the motor 31 to compress external air according to an operating condition and supply it to the combustion chamber.

The control apparatus for a hybrid vehicle according to an embodiment of the present invention varies the outputs of the engine 10 and the driving motor 50 according to the state of charge (SOC) of the battery 70.

The low voltage direct current converter (LDC) converts the low voltage direct current output from the battery 70 into direct current corresponding to the operating voltage of the corresponding component. That is, the low-voltage DC converter converts the low-voltage direct current output from the battery 70 into a direct current corresponding to the operating voltage of the electric supercharger 30 and/or the direct current corresponding to the operating voltage of the electric components of the vehicle and outputs the converted.

The accelerator pedal sensor 100 (APS: acceleration pedal sensor) detects an operation of an accelerator pedal. The amount of change in the accelerator pedal sensed by the accelerator pedal sensor 100 is transmitted to the controller 90. The controller 90 may determine the required torque (or required power) according to the will of the driver to accelerate from the amount of change in the accelerator pedal sensed by the accelerator pedal sensor 100, and the driving mode is an EV mode, an HEV mode, and an engine alone. Can be selectively switched to mode.

The controller 90 controls components of the vehicle including the engine 10, the HSG 40, the drive motor 50, the electric supercharger 30, the battery 70, and the clutch 60.

To this end, the controller 90 may be provided with one or more processors operated by a set program, and the set program is adapted to perform each step of a method for controlling a hybrid vehicle according to an embodiment of the present invention.

The clutch 60 is provided between the engine 10 and the driving motor 50, and the hybrid vehicle depending on whether the clutch 60 is engaged is operated in an electric vehicle (EV) mode or a hybrid electric vehicle (HEV) mode. . The EV mode is a mode in which the vehicle is driven only by the driving force of the motor, and the HEV mode is a mode in which the vehicle is driven by the driving force of the motor and the engine 10.

The driving power output from the engine 10 and the driving motor 50 is transmitted to a driving wheel provided in the vehicle. At this time, a transmission 80 is provided between the clutch 60 and the driving wheel. A shift gear is installed inside the transmission 80 to change power output from the engine 10 and the drive motor 50 according to the shift gear stage.

Hereinafter, a method for controlling a hybrid vehicle according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, the driving information sensing unit 20 detects driving information including the temperature of the driving motor 50, the temperature of the battery 70, the driver's required torque (or requested power), and the engine speed, and the detected driving information Is transmitted to the controller 90 (S10).

The controller 90 determines whether the temperature of the drive motor 50 is lower than the first set temperature or the temperature of the drive motor 50 is higher than the second set temperature. Alternatively, the controller 90 determines whether the temperature of the battery 70 is lower than the third set temperature or the temperature of the battery 70 is higher than the fourth set temperature (S20). That is, the controller 90 determines whether the temperature of the driving motor or battery is out of the normal temperature range and is in a very low or very high state.

If the temperature of the driving motor (T _mot ) or the temperature of the battery (T _bat ) is within the normal temperature range, the controller 90 controls the engine 10 to operate at an optimal operating line (OOL). (S30).

That is, if the driver's required torque is greater than the engine torque at the optimum operating point of the engine 10, the engine output is assisted through the drive motor 50 to satisfy the driver's required torque. On the other hand, if the driver's required torque is less than the engine torque at the optimum operating point of the engine 10, the torque corresponding to the difference between the engine torque at the optimum operating point of the engine 10 and the driver's required torque is the drive motor ( 50) to generate power (in this case, the drive motor 50 operates as a generator), and the power generated through the drive motor 50 is charged to the battery 70.

When the temperature of the drive motor 50 or battery 70 is out of the normal temperature range, the driver's request based on the output limit value of the drive motor 50 determined according to the temperature of the drive motor 50 or battery 70 Determine the engine torque that can meet the torque. At this time, it is preferable that the controller 90 determines the engine torque from the optimum amount of air at which the system efficiency is maximized (S40).

The output limit value of the drive motor 50 means the maximum output power that can be output through the drive motor 50 in a low or high temperature state of the drive motor 50 or the battery 70. Accordingly, in a low or high temperature state, the output of the drive motor 50 is output below the output limit value of the drive motor 50. In this case, the output limit value of the driving motor 50 may be determined to decrease as the temperature of the driving motor 50 or the battery 70 decreases, or decrease as the temperature of the driving motor 50 or battery 70 increases.

System efficiency can be determined through the following equation.

[Equation 1]

In Equation 1, P _driver is the driver's required power, M _fuel is the amount of fuel supplied to the engine 10, LHV is the low heat value of the fuel, P _esc is the power consumed in the electric supercharger 30, and P _LDC is Power output from the DC converter, P _eng denotes engine power, η _mot denotes efficiency of the drive motor 50, and η _tran denotes power transfer efficiency.

The amount of fuel supplied to the engine 10 is determined from a function of the optimum amount of air supplied to the engine 10, the engine speed, the atmospheric pressure, and the intake air temperature. This can be expressed as an equation as follows.

[Equation 2]

In Equation 2, M _air denotes the amount of air supplied to the engine 10, RPM denotes an engine speed, AMP denotes atmospheric pressure, and TIA denotes an intake air temperature.

Specifically, the fuel flow rate is calculated through Equation 3 below, and a correction value may be applied if necessary.

[Equation 3]

In Equation 3, the air fuel ratio (AFR) is a theoretical air-fuel ratio, and in the case of a gasoline engine, a constant in the range of 14.5 to 14.7 is used.

λ is an air excess ratio, and 1 is used in most operating conditions of a gasoline engine, but has a value less than 1 in _{high RPM and high M air conditions.} Therefore, λ is _{determined experimentally according to M air} and RPM, and may be pre-stored in the controller in the form of map data or approximation. If necessary, a correction value may be applied to the air excess rate depending on atmospheric pressure or intake air temperature. The excess air rate can be corrected through the following equation.

[Equation 4]

In Equation 4, λ _final is the final air excess rate, λ _base is the initial air excess rate, λ _AMP is the atmospheric pressure correction value, and λ _TIA is the intake air temperature correction value.

The engine power P _eng is determined from a function of the optimum amount of air supplied to the engine 10, the engine speed, the atmospheric pressure, and the intake air temperature. This can be expressed as an equation as follows.

[Equation 5]

In Equation 5, M _air denotes the amount of air supplied to the engine 10, RPM denotes an engine speed, AMP denotes atmospheric pressure, and TIA denotes an intake air temperature.

Specifically, the engine power is calculated through Equation 6 below, and a correction value may be applied if necessary.

[Equation 6]

T _eng- is the engine torque, and is calculated through Equation 7 below.

[Equation 7]

In Equation 7, T _ind,max is the maximum indicated torque in the amount of _air and RPM, and is determined experimentally according to M air and RPM, and in advance in the form of map data or approximate equation in the controller. Can be saved.

η _ign means torque efficiency for ignition timing, and can be expressed as an approximation of a second or third order polynomial according to the ignition timing. The efficiency according to the ignition timing is _{determined experimentally according to M air} and RPM, and can be stored in advance in the form of map data or approximation in the controller.

T _firc is the friction torque at the corresponding air volume and RPM, _{is determined experimentally according to M air} and RPM, and can be previously stored in the controller in the form of map data or approximate formula.

Therefore, T _eng can be expressed as a function of only M _{air and RPM.} In addition, correction can be performed by applying the influence of TIA or AMP in the final calculation process of _{T eng or the calculation process of each factor.}

_{The electric power P esc} consumed by the electric supercharger 30 is determined from a function of the optimum amount of air supplied to the engine 10, the engine speed, the atmospheric pressure, and the intake air temperature. This can be expressed as an equation as follows.

[Equation 8]

In Equation 8, M _air denotes the amount of air supplied to the engine 10, RPM denotes an engine speed, AMP denotes atmospheric pressure, and TIA denotes an intake air temperature.

P _esc- is _{a function of M air} and pressure rise ratio. Mainly, it is determined experimentally and can be stored in advance in the controller in the form of map data or approximate formula.

When determining P _esc- experimentally, the test is carried out under standard conditions, and if the intake air temperature changes, it can be corrected through a factor. For example, P _esc- may be corrected as in Equation 9 below.

[Equation 9]

The pressure increase ratio (PR) represents the pressure ratio between the front end and the rear end (or upstream and downstream) of the electric supercharger in a dimensionless channel. This can be expressed as an equation as follows.

[Equation 10]

P _loss,it means the pressure loss in the intake duct, intake pipe, or air filter, etc., which can be neglected or determined experimentally and approximated by the second or third order polynomial of _{M air.}

P _boost means the required boost pressure, and can be determined experimentally as a function of _{M air and RPM.}

_{The efficiency η mot} of the drive motor is determined from a function of the optimum amount of air supplied to the engine 10, engine speed, atmospheric pressure, and intake air temperature. This can be expressed as an equation as follows.

[Equation 11]

η _mot is determined as a function of the torque and speed of the motor, is mainly determined experimentally, and can be stored in advance in the controller in the form of approximate formulas or map data.

In the case of a TMED type hybrid vehicle, the speed of the motor is the same as the speed of the engine. Therefore, the torque of the motor can be expressed as Equation 12 below.

[Equation 12]

T _driver is the driver's required torque, and T _eng can be calculated through Equation 5 above.

The power transmission efficiency η _tran is determined as a function of the power consumption of the electric supercharger 30, the power output from the DC converter, the driver's required torque, the engine power, and the efficiency of the drive motor. This can be expressed as an equation as follows.

[Equation 13]

The power transfer efficiency η _tran is a function of power consumed or supplied as a transfer efficiency in a high voltage power system of a hybrid vehicle, and may be previously stored in the controller in the form of a map data or an approximate formula.

The power consumed or supplied in the high voltage power system of the hybrid vehicle includes power consumption (P _esc ) of the electric supercharger 30, power output from the DC converter (P _LDC ), and power consumption of the motor (P _mot ). I can.

In this case, the power consumption (P _mot ) of the motor may be expressed by the following equation.

[Equation 14]

In the above equations, the driver's required power (or required torque) is a value determined from the change amount of the accelerator pedal sensed by the accelerator pedal detection sensor, and is a constant, the power output from the DC converter is a constant, and the low heat value of the fuel is also It is a constant.

_{Accordingly, the optimum air amount M air} to be supplied to the engine 10 may be determined through Equation 1 for determining system efficiency by receiving atmospheric pressure, intake air temperature, and engine speed.

The controller 90 determines the final engine torque to be output from the engine 10 from the optimum air amount (S50). This can be expressed as an equation as follows.

[Equation 15]

The controller 90 may determine _{the rotational speed of the electric supercharger 30 for supplying the determined optimum air amount M air} to the engine (S60), and accordingly determine the power consumed by the electric supercharger 30. (S60).

For example, when the operating point of the engine for outputting the final engine torque is located at the optimum operating point in the natural aspiration engine (NA), the controller 90 stops the operation of the electric supercharger 30.

On the other hand, when the operating point of the engine 10 for outputting the final engine torque is greater than the optimum operating point in the natural aspiration engine (NA), the controller 90 operates the electric supercharger 30 to make the engine 10 It is possible to control the engine 10 to be operated in the optimum operating point region by supplying supercharged air to the vehicle.

Referring to FIG. 5A, in the case of a naturally aspirated engine, an area in which the engine is operated at an optimum operating point is very narrow. On the other hand, referring to FIG. 5B, in the case of an engine to which the electric supercharger 30 is applied, compared to a naturally aspirated engine, an area in which the engine is operated at an optimum operating point is relatively very wide.

Therefore, when the temperature of the drive motor or battery is very low or high, even if the amount of power assistance by the drive motor 50 decreases, the engine is operated in the optimum operating point region to improve the fuel economy of the vehicle and reduce the emission. I can.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the accompanying drawings, and this is also the present invention. It is natural to fall within the scope of the invention.

10: engine
11: intake line
30: electric supercharger
40: HSG
50: drive motor
60: clutch
70: battery
80: transmission
90: controller
100: accelerator pedal sensor

Claims (6)

An engine that generates power by burning fuel;
A driving motor that assists the power of the engine and selectively operates as a generator to generate electric energy;
A clutch provided between the engine and the drive motor;
A battery that supplies electric energy to the drive motor or charges electric energy generated by the drive motor;
A DC converter for converting DC output from the battery;
An electric supercharger supplying supercharged air to the engine; And
An optimum amount of air at which system efficiency is maximized is determined based on an output limit value of the driving motor according to the temperature of the driving motor or the battery, and engine power output from the engine and output from the driving motor based on the optimum air amount A controller for determining the driving motor power to be applied;
Hybrid vehicle control device comprising a. The method of claim 1,
The system efficiency is
The driver's required power, the amount of fuel supplied to the engine, the low heat value of the fuel, the power consumed by the electric supercharger, the power consumed by the DC converter, the engine power output from the engine, the efficiency of the driving motor, and the power Hybrid vehicle control device determined from transmission efficiency. The method of claim 2,
The system efficiency is

Is determined from the equation of,
Here, P _dirver is the driver's required power, M _fuel is the amount of fuel supplied to the engine, LHV is the low heat value of the fuel, P _esc is the power consumed by the electric supercharger, P _LDC is the power consumed by the DC converter, P _eng Is the engine power, η _mot is the efficiency of the driving motor, and η _tran is the power transfer efficiency of the hybrid vehicle control unit. Receiving, by the controller, driving information including a temperature of a driving motor, a temperature of a battery, a required power of a driver, and an engine speed;
By the controller, when the temperature of the driving motor or the temperature of the battery is out of a set temperature range, the system efficiency is maximized based on an output limit value of the driving motor or the driving motor determined according to the temperature of the battery. Determining the amount of air;
Determining, by the controller, an engine torque output from the engine from the optimum air amount; And
Determining an output torque of the drive motor to meet a driver's required torque from the engine torque;
Control method of a hybrid vehicle comprising a. The method of claim 4,
The system efficiency is
The driver's required power, the amount of fuel supplied to the engine, the low heat value of the fuel, the power consumed by the electric supercharger, the power output from the DC converter, the engine power output from the engine, the efficiency of the drive motor, and the Hybrid vehicle control method determined from power transfer efficiency. The method of claim 5,
The system efficiency is

Is determined from the equation of,
Here, P _dirver is the driver's required power, M _fuel is the amount of fuel supplied to the engine, LHV is the low heat value of the fuel, P _esc is the power consumed by the electric supercharger, P _LDC is the power consumed by the DC converter, P _eng Is the engine power, η _mot is the efficiency of the driving motor, and η _tran is the power transfer efficiency.

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