KR20050070579A - Method for recovering margin of electric energy on driving of vehicle - Google Patents

Abstract

The present invention sets the amount of power generation during deceleration or constant speed driving according to the state of charge (SOC) of a battery in a hybrid vehicle, and then sets a certain level of charge state during deceleration or constant speed driving. (SOC) relates to a method of recovering the extra electric energy when driving the vehicle to reduce the electric energy from the motor to the battery,

Electrical energy recovery method according to the invention, the first step of generating a rotational force by driving the engine; A second step of obtaining a vehicle speed VSPi and an accelerator pedal output value TPSi through an engine speed detector and an acceleration detector, and determining whether the engine speed is below a predetermined value; A third step of recognizing a deceleration state and determining the state of charge (SOC) through a state of charge detection unit when the vehicle speed VSPi and the accelerator pedal output value TPSi have a predetermined value or less; And when the state of charge SOC is less than or equal to the minimum value A, a regeneration value as a table value according to the vehicle speed, and controlling the reverse current to be applied to the battery when the state of charge SOC is less than or equal to the minimum value A. And a fourth step.

Description

{Method for Recovering Margin of Electric Energy on Driving of Vehicle}

The present invention relates to a method of recovering a marginal electric energy when driving a vehicle, and more particularly, how much power is generated during deceleration or constant speed driving according to a state of charge (SOC) of a battery in a hybrid vehicle. After setting the, when the state of charge (SOC) at a predetermined level during deceleration or constant speed driving, the present invention relates to a method of recovering the excess electrical energy during driving of the vehicle to reduce the electrical energy from the motor to the battery.

In order to prevent air pollution and to conserve petroleum energy resources, countries around the world are implementing CO ₂ regulations, and in some countries, incentives are motivating not only consumers but also automobile manufacturers.

   One of the methods to achieve such excellent fuel economy has been introduced to reduce the unnecessary consumption or wasted energy stored in the battery (Battery), and then recycled through the motor if necessary. Such a system is called a hybrid system and usually uses energy as an internal combustion engine and accelerates or drives a motor at constant speed to assist the battery with power, thereby lowering fuel consumption. .

1 is a view showing the structure of a conventional engine control device for charging electrical energy.

As shown in FIG. 1, in order to charge a battery, energy may be reduced only when there is a marginal energy during deceleration and during constant speed. In the method of reducing energy during deceleration, when a reverse current flows using a motor, when a reverse torque is applied, the vehicle decelerates with a brake effect, and the current generated therein is a large capacity installed in the vehicle. The battery will be stored (charged) at this time. Of course, this sense of deceleration is inevitable for regeneration through the motor, but it does not need to be as little or unnecessary as possible. However, current hybrid systems are designed to always generate a certain amount of current regardless of the state of the battery, so that the battery can be charged even when the battery is full and no further charging is possible. Continue the reduction operation. Therefore, the driver has a problem in that it is necessary to accept the disadvantages of only driving performance without benefit in terms of energy saving.

The present invention for solving the above problems, after setting how much the amount of power generated during deceleration or constant speed driving according to the state of charge (SOC) of the battery in a hybrid vehicle, deceleration or constant speed It is an object of the present invention to provide a method of recovering electric energy when driving a vehicle that reduces electric energy from a motor to a battery when the state of charge (SOC) reaches a predetermined level during driving.

In order to achieve the above object, the present invention is a spare electrical energy recovery method for reducing electrical energy from the motor to the battery when a certain level of state of charge (SOC) at the time of deceleration or constant speed driving, a method for generating a rotational force by driving the engine Stage 1; A second step of obtaining a vehicle speed VSPi and an accelerator pedal output value TPSi through an engine speed detector and an acceleration detector, and determining whether the engine speed is below a predetermined value; A third step of recognizing a deceleration state and determining the state of charge (SOC) through a state of charge detection unit when the vehicle speed VSPi and the accelerator pedal output value TPSi have a predetermined value or less; And when the state of charge SOC is less than or equal to the minimum value A, a regeneration value as a table value according to the vehicle speed, and controlling the reverse current to be applied to the battery when the state of charge SOC is less than or equal to the minimum value A. It provides a method for recovering the marginal electric energy during vehicle driving, comprising a fourth step.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings.

In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In the present invention, the measurement structure of the state of charge (SOC) in the hybrid vehicle is used in the same manner, and with the measured level of state of charge (SOC), the amount of power generation at the time of deceleration or constant speed operation is set as a criterion of determination. For example, if the SOC is above a certain level of charge, the regeneration itself is eliminated, thereby improving the vehicle deceleration.

2 is a block diagram illustrating a configuration of a battery charge control apparatus of a hybrid vehicle for explaining a method of recovering a marginal electric energy when driving a vehicle according to an exemplary embodiment of the present invention.

The battery charge control apparatus 200 for explaining a method of recovering a spare electrical energy according to the present invention includes an engine 210, an electric motor 220, a battery 230, a charge state detector 240, a memory 250, The engine speed detector 260, the acceleration detector 270, and the electronic control unit (ECU) 280 have a configuration.

The engine 210 transmits rotational power to the wheels, and the driving speed is changed by the incoming fuel.

The electric motor 220 rotates in the same manner as the rotational force of the engine 210 and performs power generation according to the rotational force.

The battery 230 charges electrical energy generated by the electric motor 220.

The state of charge detection unit 240 detects the state of charge (SOC) of the battery 230, the memory unit 250 stores a data value related to a predetermined reference power, and stores a reference value to determine the state of charge (SOC) Doing.

The engine speed detector 260 detects a rotation speed of the engine 210, and the acceleration detector 270 detects an accelerator pedal depression state of the vehicle and generates an electrical output signal corresponding thereto.

The electronic controller 280 compares and computes a value input from each detector with a preset reference value to perform an overall control operation related to battery charging.

3 is a flowchart illustrating a method of recovering spare electric energy when driving a vehicle according to an exemplary embodiment of the present invention.

The hybrid vehicle is cranked by the electric motor 220 when cranking the engine 210, and assists power using electric energy in an acceleration mode. This section is the section using electric energy. Therefore, in this section, the state of charge (SOC) of the battery gradually decreases.

In the deceleration mode, the electric motor 220 acts as a generator to store electrical energy in the battery 230. Therefore, the state of charge (SOC) gradually increases.

If the amount of energy recovered during acceleration and the amount of energy recovered during deceleration are exactly the same, depletion of electric energy can be prevented, but the power generation efficiency of the electric motor 220 is lower than the drive efficiency of the electric motor 220, and acceleration When the electrical energy used at the time is greater than the amount of electrical energy recovered at the time of deceleration, the state of charge (SOC) value indicating the electrical energy available state of the battery 230 gradually decreases.

When the hybrid vehicle is started and supplied with power, the electronic controller 280 drives the engine 210 to generate rotational force, and transmits the generated rotational force to the wheel by the transmission (S310).

Accordingly, the vehicle starts to drive, and the driving speed of the engine 210 is varied according to the amount of the driver's accelerator pedal to change the driving speed of the vehicle.

The electronic controller 280 obtains the vehicle speed VSP and the accelerator pedal output value TPS through the engine speed detector 260 and the acceleration detector 270, and sets the vehicle speed VSP and the accelerator pedal output value TPS below a predetermined value. Determination of the deceleration by determining whether or not having (S320).

If it is determined that the vehicle speed VSP and the accelerator pedal output value TPS have a predetermined value (VSPi ≦ VSPi-1 and TPSi ≦ TPSi-1) (S330), the electronic controller 280 recognizes that the vehicle is in a decelerated state. Then, the state of charge is determined through the state of charge detector 240 (S340).

As described above, while the vehicle is driving, the charging state detector 240 detects the charging state of the battery 230 and outputs an electrical signal corresponding thereto to the electronic controller 280.

If the state of charge (SOC) value of the battery 230 is a normal state, the optimum charge amount can be obtained in consideration of the power generation efficiency of the electric motor 220 in a section that can supply the electric energy required by the current vehicle. Control is made.

The engine speed of the parallel hybrid vehicle in which the engine 210 and the electric motor 220 are directly connected is the same as the speed of the electric motor 220. Since the electric motor 220 is controlled by the torque command, the engine 210 determines the torque having the maximum efficiency at the current engine speed (electric motor speed), so that the engine 210 can afford the generated power. That is, it does not always require a constant generation power, but by optimizing the generation power according to the situation to prevent the state of charge (SOC) value of the battery 210 possible to fall below the preset minimum value by variably selecting the generation power. do.

The electronic controller 280 detects a value corresponding to the state of charge (SOC) of the battery.

The electronic controller 280 reads the minimum value A serving as a reference for determining the state of charge from the table preset in the memory unit 250, and compares the detected state of charge (SOC) with a value smaller than the minimum value A. It is determined (S350).

If the state of charge (SOC) of the battery 230 is less than the minimum value (A: 35%), it is necessary to charge a large amount as soon as possible in a state in which the remaining energy of the battery 210 is insufficient. In this case, although the power generation efficiency of the electric motor 220 is somewhat poor, the charging efficiency of the battery is good and the power generation power is constantly determined so that the battery can be restored to a normal state within a short time.

Therefore, the electronic controller 280 brings the regeneration value to the table value according to the vehicle speed, and controls the reverse current to be applied with SOC ≤ A (S360).

On the other hand, if the state of charge SOC is greater than or equal to the minimum value, the electronic controller 280 determines whether the state of charge SOC is less than or equal to the maximum value B (S370).

If the state of charge (SOC) is less than or equal to the maximum value (B), the electronic controller 280 brings the regeneration value to a table value according to the vehicle speed, and controls to apply a reverse current in a state of SOC ≤ B (S380). .

However, when the state of charge (SOC) of the battery 210 is greater than the maximum value (B: 70%), power generation by the separate engine is not performed. That is, the electronic controller 280 prohibits regeneration (S390). This is because there is sufficient electric energy available, and there is no reason to generate power while consuming fuel in a section where the charging efficiency of the battery is rapidly deteriorated.

The electronic controller 280 calculates power generation power by calculating the detected engine speed and torque of the vehicle, and controls the charging operation of the battery 230 by the calculated power generation power.

According to an embodiment of the present invention, after setting the amount of power generated during deceleration or constant speed driving according to the state of charge (SOC) of the battery in the hybrid vehicle, when the state of charge (SOC) at a predetermined level during deceleration or constant speed driving is set. A spare electric energy recovery method can be realized when the vehicle travels to reduce the electric energy from the motor to the battery.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention.

Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments.

The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

As described above, according to the present invention, the reduction of electrical energy (Regeneration) can be maximized to increase the fuel consumption rate. Accordingly, the driver's appeal and competitiveness can be secured.

In addition, when the state of charge (SOC) can not charge any more electrical energy in the battery, it is applied to the driving aspect rather than the energy reduction mode to prevent unnecessary deterioration of driving performance (deceleration feeling during deceleration). Improvement).

1 is a view showing the structure of a conventional engine control apparatus for charging electrical energy;

2 is a block diagram showing the configuration of a battery charging control device of a hybrid vehicle for explaining a method of recovering a marginal electric energy when driving a vehicle according to an embodiment of the present invention;

3 is a flowchart illustrating a method of recovering spare electric energy when driving a vehicle according to an exemplary embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

200: battery charge control device 210: engine

220: electric motor 230: battery

240: charge state detection unit 250: memory unit

260: engine speed detection unit 270: acceleration detection unit

280: ECU

Claims (4)

As a state of charge (SOC) when decelerating or driving at a constant speed, the electric energy is recovered from the motor to the battery as a spare electric energy recovery method. A first step of driving the engine 210 to generate rotational force; A second step of obtaining a vehicle speed VSPi and an accelerator pedal output value TPSi through the engine speed detector 260 and the acceleration detector 270 and determining whether the engine speed is less than a predetermined value; A third step of recognizing a deceleration state and determining the state of charge (SOC) through a state of charge detector 240 when the vehicle speed VSPi and the accelerator pedal output value TPSi have a predetermined value or less; And When the state of charge SOC is less than or equal to the minimum value A, a regeneration value is set as a table value according to the vehicle speed, and the reverse current of the state where the state of charge SOC is less than or equal to the minimum value A is the battery 230. And a fourth step of controlling to be applied to the vehicle. The method of claim 1, In the fourth step, if the state of charge (SOC) is more than the minimum value (A), it is determined whether the state of charge (SOC) is less than the maximum value (B), When the state of charge SOC is less than or equal to the maximum value B, a reverse current in a state in which the state of charge SOC is greater than or equal to the minimum value A and less than or equal to the maximum value B is controlled to be applied to the battery 230. Free electric energy recovery method during vehicle driving. The method of claim 2, If the state of charge (SOC) is equal to or greater than the maximum value (B), the regeneration is inhibited, and power generation by the engine is not performed separately. The method of claim 1, The predetermined value or less VSPi ≤ VSPi-1 and TPSi ≤ TPSi-1 characterized in that the extra electric energy recovery method when driving the vehicle.