KR102456071B1 - Regenerative braking control methods and devices on P1/P2 type parallel hybrid vehicles - Google Patents

Abstract

Disclosed are a regenerative braking control method and device on a P1/P2 type parallel hybrid vehicle, wherein an engine, an engine clutch and a transmission are arranged in a line, a P1 motor is provided between the engine clutch and the engine to transmit and receive power to and from the output shaft of the engine, and a P2 motor is provided between the engine clutch and the transmission to transmit and receive power to and from the input shaft of the transmission. The regenerative braking control method on a P1/P2 type parallel hybrid vehicle according to the present invention comprises the steps of: determining whether the SOC requires fast charging; and if the SOC requires fast charging, determining whether the vehicle is currently in an EV mode in which the vehicle drives using only the output of the P2 motor; if the SOC requires fast charging and the vehicle is currently driving in an EV mode, requesting the start of the engine; raising the rotating velocity of the P1 motor to the rotating velocity of the P2 motor together with the start of the engine caused by the request for engine start; determining whether the rotating velocity of the P1 motor and the engine satisfies a predetermined condition; if the predetermined condition is satisfied, requesting downshift to a lower gear stage than the current gear stage; and performing slip control of the engine clutch to use kinetic energy transmitted from vehicle wheels by the downshift as energy for regenerative braking of the P1 motor as well as a second motor. Therefore, a regenerative braking amount can be increased greatly.

Description

Regenerative braking control methods and devices on P1/P2 type parallel hybrid vehicles

The present invention relates to a method and apparatus for controlling regenerative braking of a hybrid vehicle, in particular, an engine, an engine clutch, and a transmission are arranged in a line, a P1 motor is arranged between the engine clutch and the engine, and a P2 motor is arranged between the engine clutch and the transmission To a method and apparatus for controlling regenerative braking of a P1/P2 type parallel hybrid vehicle equipped with

In order to improve the atmospheric environment, there is a trend of strengthening the exhaust gas regulation of vehicles day by day. However, existing power trains based on gasoline or diesel engines have limitations in meeting the stricter exhaust gas regulations. Accordingly, research and development of a new power train system to meet the ever-strengthening exhaust gas regulations are being actively conducted.

Hybrid systems are one of many technologies to meet increasingly stringent emission standards. A hybrid system refers to a system in which an electric motor assists the output of an engine or drives a vehicle by an electric motor alone. In general, such a hybrid system can be divided into a parallel-type hybrid and a series-type hybrid.

The engine is used only for power generation and the method of driving the vehicle only with the motor is a series hybrid. Compared to the parallel type, the serial type has the advantage of relatively simple structure and simple control logic. However, since the mechanical energy generated by the engine is converted into electrical energy, stored in the battery, and then the vehicle is driven again using the motor, it is not reasonable in terms of energy efficiency.

On the other hand, the parallel type has a disadvantage in that the structure is relatively complex and the control logic is also complicated than that of the serial type. However, there is an advantage in that the mechanical energy of the engine and the energy of the battery can be used at the same time, so that the energy can be used efficiently. In addition, it is advantageous in terms of manufacturing cost because it can be designed without a major change in the drive system in an existing internal combustion engine vehicle.

Accordingly, development cases for parallel hybrids are on the rise. These parallel hybrids are divided into P0, P1, P2, P3, P4 types, etc. depending on where the motor that generates driving force for vehicle driving is located in the vehicle dynamometer in cooperation with the engine or alone, and according to each type Different power distribution control strategies are required.

Among them, in the P1/P2 type, as shown in FIG. 1 , the engine 10 , the engine clutch 20 , and the transmission 30 are arranged in a line on a coaxial line, and the engine clutch 20 and the engine 10 . Between the P1 motor (P1) is provided to transmit and receive power to the output shaft of the engine 10, and between the engine clutch 20 and the transmission 30, power is applied to the input shaft of the transmission 30 Refers to a system provided with a P2 motor (P2) for sending and receiving.

Such a P1/P2 type hybrid system considers the current vehicle speed, driver's demand output, SOC (State Of Charge), etc. The vehicle is driven by selecting a driving mode that can bring out optimal power efficiency and fuel economy under the current driving conditions among the modes that drive the vehicle only by output), and switching to the selected driving mode.

Among them, when the EV mode that drives the vehicle only with the output of the pure motor is selected, the P2 motor ( P2 motor ( P2 ) The vehicle is driven only by the output of P2). At this time, the engine clutch 20 is opened so that the engine drag torque does not interfere with the output of the P2 motor.

This P1/P2 hybrid system has relatively superior power efficiency and mechanical efficiency during regenerative braking compared to the existing P0/P2 method that uses a mechanical element called a belt-pulley, but the existing P2 motor generates power during regenerative braking. The regenerative braking method has a problem in that it is difficult to quickly respond to a situation in which fast charging is required because the remaining amount of the battery drops to a dangerous level due to rapid battery exhaustion.

Japanese Patent Application Laid-Open No. 2014-133529 (published on July 24, 2014)

The technical problem to be solved by the present invention is to improve fuel efficiency by increasing the amount of regenerative braking of a P1/P2 type parallel hybrid vehicle, and to quickly set the SOC when the state of charge (SOC) drops sharply due to a sudden increase in load An object of the present invention is to provide a method and apparatus for controlling regenerative braking of a P1/P2 type parallel hybrid vehicle that can be raised to a higher level.

According to one aspect of the present invention as a means of solving the problem,

An engine, an engine clutch, and a transmission are arranged in a line, and a P1 motor is provided between the engine clutch and the engine to transmit and receive power to an output shaft of the engine, and a P2 motor is disposed between the engine clutch and the transmission on an input shaft of the transmission. In a hybrid vehicle equipped to transmit and receive power,

(a) determining whether the SOC requires fast charging;

(b) determining whether the vehicle is in an EV mode in which the vehicle is currently driven only by the output of the P2 motor if the SOC requires fast charging;

(c) requesting engine start if the SOC requires fast charging and the vehicle is currently driving in EV mode;

(d) increasing the rotation speed of the P1 motor to the rotation speed of the P2 motor together with the engine starting according to the engine start request;

(e) determining whether the rotation speeds of the P1 motor and the engine satisfy a predetermined condition;

(f) requesting a downshift to a lower gear than the current gear when the predetermined condition is satisfied; and

(g) slip control of the engine clutch to use the kinetic energy transmitted from the vehicle wheels according to the downshift as energy for regenerative braking of the P1 motor as well as the second motor. A method for controlling regenerative braking of a hybrid vehicle is provided.

Preferably, in the step (a), if the SOC is less than or equal to the preset setting value (A), it may be determined that a fast charging is required.

In addition, in step (e), if the rotation speed of the P1 motor rotating with the engine output is the same as the rotation speed of the P2 motor, and the difference between the engine rotation speed and the rotation speed of the P1 motor is less than a certain value, the predetermined condition is satisfied can be judged as

The method for controlling regenerative braking of a P1/P2 type parallel hybrid vehicle according to an aspect of the present invention also includes:

(h) monitoring the SOC in real time after step (g), and determining whether to switch engine clutch control or request a downshift to a lower stage according to the monitoring result; may further include.

Preferably, in step (h), after the engine clutch slip control through step (g), it is monitored in real time whether the SOC reaches a preset set value (B), and when the SOC reaches the set value (B), the engine clutch can be switched from slip to close.

On the other hand, if the SOC does not reach the set value (B) after a certain period of time, it may be programmed to return to the step (f), request a downshift to a lower stage, and repeat the subsequent process.

According to another aspect of the present invention as a means of solving the problem,

An engine, an engine clutch, and a transmission are arranged in a line, and a P1 motor is provided between the engine clutch and the engine to transmit and receive power to an output shaft of the engine, and a P2 motor is disposed between the engine clutch and the transmission on an input shaft of the transmission. In a hybrid vehicle equipped to transmit and receive power,

an EMS controller for controlling the engine start on/off and output;

a BMS controller that supplies power to the P1 motor and the P2 motor or controls charging/discharging of a high voltage battery charged by the P1 motor and the P2 motor;

a hybrid control unit (HCU) for controlling the speeds of the P1 motor and the P2 motor; and

It includes; the EMS controller and the BMS controller, and a TMS controller for controlling the shift stage and the engine clutch of the transmission in cooperation with the HCU,

The TMS controller requests the EMS controller to start the engine, and after starting the engine, the TMS controller requests the EMS controller to start the engine when the SOC of the high-voltage battery falls below the set value (A) and fast charging is required and the current vehicle driving mode is the EV mode. Provided is a regenerative braking control apparatus for a P1/P2 type parallel hybrid vehicle that performs slip control of the engine clutch with downshift when the state satisfies a predetermined condition.

Preferably, when the SOC of the high voltage battery falls below a set value (A), the BMS controller determines that a fast charging is required, and transmits a fast charging request signal to the TMS controller, and the TMS controller requests the fast charging Analyzes the signal from the HCU and EMS controller at the time of receiving the signal to determine whether the vehicle is currently in EV mode in which only the output of the P2 motor is driven, and if the vehicle is currently driving in EV mode, requests the EMS controller to start the engine At the same time, an engine power increase request is made so that the rotation speed of the P1 motor rises to the rotation speed of the P2 motor. When the difference between the engine rotation speed and the rotation speed of the P1 motor is equal to or less than a certain value, it is determined that the predetermined condition is satisfied, and the gear shift stage is downshifted to a lower stage than the current gear stage, and the engine clutch is slip controlled. can

In addition, the TMS controller monitors the SOC of the high voltage battery in real time in cooperation with the BMS controller in the engine clutch slip control state with downshift execution, and when the SOC reaches a preset set value (B), the engine clutch is set from slip It can be switched to the closed state.

On the other hand, if the SOC does not reach the set value B even after a predetermined time elapses during SOC monitoring, the TMS controller may perform a control for downshifting the shift stage to a lower stage.

According to an embodiment of the present invention, when a situation in which the SOC is suddenly insufficient occurs, regenerative braking occurs not only in the P2 motor but also in the P1 motor through the engine clutch control and the shift stage control, so regenerative braking is performed only with the P2 motor. The amount of regenerative braking can be significantly increased. As a result, there is an advantage in that it is possible to quickly respond to a situation in which the SOC has rapidly dropped due to a sudden increase in load.

1 is a schematic diagram showing a power transmission structure of a conventional P1/P2 type parallel hybrid vehicle.
2 is a diagram schematically illustrating a main configuration of a P1/P2 type parallel hybrid vehicle including a regenerative braking control device according to an embodiment of the present invention.
3 is a control flowchart of the present invention sequentially illustrating a series of regenerative braking control processes performed by the regenerative braking device of FIG. 2 .

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

In describing the present invention, the terms used in the following specification are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise.

In addition, in this specification, terms such as "comprise" or "have" are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, but one or more other It is to be understood that this does not preclude the possibility of addition or presence of features or numbers, steps, operations, components, parts, or combinations thereof.

Also, terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

In addition, terms such as “…unit”, “…unit”, “…module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. can

In the description with reference to the accompanying drawings, the same reference numerals will be assigned to the same components, and repeated descriptions of the same components will be omitted. And, in the description of the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

2 is a diagram schematically illustrating a main configuration of a P1/P2 type parallel hybrid vehicle including a regenerative braking control device according to an embodiment of the present invention. The regenerative braking control device according to an embodiment of the present invention applied to such a P1/P2 type parallel hybrid vehicle will be described with the same reference numerals for the same configuration as in FIG. 1 above for convenience of explanation. do it with

Referring to FIG. 2 , a P1/P2 type parallel hybrid vehicle includes two motors P1 and P2 disposed between an engine 10 and a transmission 30 . An engine clutch 20 is installed between the engine 10 and the transmission 30 to intermittently transmit power therebetween. At this time, one of the two motors (P1 motor) is installed between the engine 10 and the engine clutch 20 , and the other (P2 motor) is installed between the engine clutch 20 and the transmission 30 .

In other words, in the P1/P2 type parallel hybrid vehicle, as shown in FIG. 2 , the engine 10 , the engine clutch 20 , and the transmission 30 are arranged in a line on the same axis, and the engine clutch 20 and the engine 10 ), the P1 motor (P1) is provided to transmit and receive power to the output shaft of the engine 10, and between the engine clutch 20 and the transmission 30, power is applied to the input shaft of the transmission 30 A P2 motor P2 is provided to transmit and receive.

The regenerative braking control apparatus according to an embodiment of the present invention applied to the P1/P2 type parallel hybrid vehicle is configured with a plurality of controllers. The plurality of controllers include an EMS (Engine Management System) controller 40 and a BMS (Battery Management System) controller 50 , and a Hybrid Control Unit (HCU) 60 , and a TMS (Transmission Management System) controller 70 . can

The plurality of controllers (EMS controller 40, BMS controller 50, TMS controller 70, and HCU 60) includes a driver's requested output determined according to an accelerator pedal operation, a current driving speed of the vehicle, and a state of (SOC). Charge, battery charge state) selects a mode that can bring out optimal power efficiency among engine mode, hybrid mode, and EV mode, and performs mutually cooperative control to implement a power transmission system suitable for the selected driving mode.

For reference, the engine mode is a mode in which the vehicle is driven only by the output of the engine 10 , and the hybrid mode refers to a mode in which the vehicle is driven by using the output of the engine 10 and the motor together. In addition, the EV mode is a mode in which the vehicle is driven purely by the driving force of the motor, and in the P1/P2 type parallel hybrid vehicle to which the present invention is applied, the vehicle is driven only by the output of the P2 motor (P2).

The EMS controller 40 controls the starting on/off and output of the engine 10, and the BMS controller 50 supplies power to the P1 motor P1 and the P2 motor P2 or the P1 motor P1. and P2 control charging/discharging for the high voltage battery charged by the motor P2. In addition, the HCU 60 serves to individually control the speeds of the P1 motors P1 and P2 motors P2 according to the request of the TMS controller 70 .

The TMS controller 70 cooperates with the EMS controller 40 , the BMS controller 50 , and the HCU 60 to implement a power transmission system suitable for the selected driving mode, as well as control the gear stage of the transmission 30 , as well as the engine. Controls the states of the clutch 20 (OPEN, SLIP, and CLOSE). In addition, in cooperation with the EMS controller 40 and the BMS controller 50 , a signal for controlling the output of the P1 motor P1 and the P2 motor P2 is transmitted to the HCU 60 .

For example, when it is decided to switch to the EV mode, the TMS controller 70 makes a request to the EMS controller 40 to turn off the engine start, and at the same time, the energy of the high voltage battery (not shown) is transferred to the P2 motor ( The power supply request is made to the BMS controller 50 only for the P2 motor P2 so that it is applied only to P2). In addition, a command for opening (OPEN) the engine clutch 20 is transmitted to a clutch actuator (not shown) so that the engine drag torque does not interfere with the output of the P2 motor P2.

The TMS controller 70 also monitors the SOC state of the high voltage battery in real time based on the information transmitted from the BMS controller 50 . As a result, if the SOC falls below the set value (A) due to a sudden increase in load and a fast charging is required and the current driving mode of the vehicle is EV mode, in order to create a vehicle state that can maximize the amount of regenerative braking along with switching to regenerative braking. Collaborate with other controllers.

More specifically, if the SOC is equal to or less than the set value (A) and is in the EV mode, first, the EMS controller 40 is requested to start the engine. And when the state of the P1 motor P1 and the engine 10 satisfies a predetermined condition after starting the engine, the kinetic energy transferred from the vehicle wheels and the engine 10 by slip-controlling the engine clutch 20 together with the downshift With the generated kinetic energy, the P1 motor (P1) and the P2 motor (P2) are simultaneously generated to increase the amount of regenerative braking.

Let's take a closer look at the regenerative braking control performed by the TMS controller when the SOC falls below the set value (A) due to a sudden load increase and a fast charging is required and the current driving mode of the vehicle is the EV mode.

When the SOC of the high voltage battery falls below the set value (A), the BMS controller 50 determines that fast charging is required, and transmits a fast charging request signal to the TMS controller 70 . Then, the TMS controller 70 analyzes the signals of the HCU 60 and the EMS controller 40 at the time when the fast charging request signal is received, and determines whether the vehicle is in an EV mode in which the vehicle is currently driven only by the output of the P2 motor P2. .

As a result of the determination, if the current driving mode of the vehicle is the EV mode, the engine start is requested to the EMS controller 40 to switch to the HEV mode and the rotation speed of the P1 motor P1 is the rotation speed of the P2 motor P2. Request to increase engine power to increase to speed. If the vehicle driving mode at the time the fast charging request signal is received is the HEV mode, regenerative braking is already in progress, and thus the control is terminated without subsequent control.

In response to the engine start and engine power increase request, the rotation speed of the P1 motor P1 rotating with the output of the engine 10 is the same as the rotation speed of the P2 motor P2 and the engine 10 rotation speed and the P1 motor P1 If the difference in the rotation speed of ' is equal to or less than a predetermined value, it is determined that the above-described predetermined condition is satisfied, and the gear shift stage is down-shifted to a lower stage than the current gear stage, and the engine clutch 20 is slip-controlled.

The reason for driving the engine 10 to make the rotation speed of the P1 motor P1 equal to the rotation speed of the P2 motor P2 is that both motors ( P1 motor and P2 motor) is to prevent the occurrence of a sense of difference in the vehicle due to the speed difference, and when downshifting, the amount of regenerative braking can be increased as the kinetic energy transmitted from the wheels increases during coasting or deceleration driving.

When the engine clutch 20 is switched to the slip control state along with the downshift, the P1 motor P1 and the P2 motor P2 are operated by the kinetic energy transmitted from the vehicle wheels and the kinetic energy generated from the engine 10. Since power is generated at the same time, the battery charging speed is much faster than the prior art in which regenerative braking is performed only with the P2 motor (P2).

In this way, in a situation where power is generated by two motors (P1 motor P1 and P2 motor P2), the TMS controller 70 cooperates with the BMS controller 50 according to the simultaneous power generation of the two motors P1 and P2. Real-time monitoring of SOC of high voltage battery. At this time, when the SOC reaches the preset set value (B), it is determined that regenerative braking can be performed only with the P2 motor P2, the P1 motor P1 switches to a no-load state, and the engine clutch 20 is closed. to minimize the engine 10 power loss.

On the other hand, if the SOC does not reach the set value (B) for a predetermined period of time during SOC monitoring, the TMS controller 70 more actively uses the vehicle's kinetic energy for regenerative braking to reduce the amount of regenerative braking. A control of downshifting the shift stage to a lower stage may be performed to increase the number of shifts.

To this end, the TMS controller 70 applied to the present invention may be equipped with one or more processors operating by a set program, wherein the set program is a P1/P2 type parallel type according to an embodiment of the present invention to be described later. It may include a series of commands for performing a predetermined process step by step included in the regenerative braking control method of the hybrid vehicle.

Hereinafter, a series of regenerative braking control processes performed by the regenerative braking control apparatus for the P1/P2 type parallel hybrid vehicle according to the embodiment of the present invention described above will be described with reference to the control flowchart of FIG. 3 . For convenience of description, the configuration shown in FIG. 2 will be described with reference to the corresponding reference numerals.

Referring to FIG. 3 , the regenerative braking control performed by the regenerative braking control apparatus of the aforementioned P1/P2 type parallel hybrid vehicle starts from the step S100 of determining whether the SOC requires fast charging. Specifically, in step S100, when the SOC is sharply lowered due to a sudden increase in load and falls below the preset setting value (A), it can be determined that fast charging is required.

As a result of the determination through step S100, if it is determined that fast charging is required because the SOC is less than or equal to the set value (A), it is successively determined whether the vehicle is currently in EV mode (S200). Here, in the EV mode, the engine 10 is turned off and the vehicle is driven only with the output of the P2 motor P2, but the engine clutch 20 is opened ( It means driving in the OPEN state.

Continuing, if the SOC requires fast charging and the vehicle is currently driving in the EV mode, it is switched to the step S300 of requesting engine start. In step S300, the above-described TMS controller 70 requests the EMS controller 40 to start the engine, and according to the start request of the TMS controller 70, the EMS controller 40 receives the request (start request). The starting device for starting the engine 10 is operated.

When the engine is started according to the engine start request, the engine 10 output is temporarily increased to increase the rotation speed of the P1 motor P1 to the rotation speed of the P2 motor P2 ( S400 ). This is a kind of pre-preparation to prevent a sense of vehicle heterogeneity that may occur when the speed difference between the two motors (P1 motor (P1) and P2 motor) is large when the engine clutch 20 is operated (engine clutch 20 slip control) in the subsequent process. It is a process.

When the rotation speed of the P1 motor P1 is increased by the step S400 , a step S500 of determining whether the rotation speed of the P1 motor P1 and the engine 10 satisfies a predetermined condition is sequentially performed. Specifically, in step S500, the rotation speed of the P1 motor P1 rotating with the engine 10 output is the same as the rotation speed of the P2 motor P2, and the rotation speed of the engine 10 and the rotation speed of the P1 motor P1 is If the difference is equal to or less than a predetermined value, it may be determined that the predetermined condition is satisfied.

As a result of the determination through step S500, if the above-described predetermined condition is satisfied, a step (S600) of requesting a downshift of the shift stage of the transmission 30 to a lower stage than the current shift stage proceeds, and the downshift is performed according to the request. Upon completion, the process is switched to the step S700 of slip-controlling the engine clutch 20 so that the kinetic energy transferred from the vehicle wheels can be used together as energy for regenerative braking of the P1 motor P1 as well as the second motor. .

After step S700, the TMS controller 70 monitors the SOC in real time based on the information about the SOC provided by the BMS controller 50, and switches the control of the engine clutch 20 or moves to a lower stage according to the monitoring result. It is determined whether to request a downshift (S800).

Specifically, in step S800, after the engine clutch 20 slip control through step S700, it is monitored in real time whether the SOC reaches a preset set value (B), and when the SOC reaches the set value (B), the engine clutch 20 is switched from sleep to close (S810), and if the SOC does not reach the set value (B) for a certain period of time, return to step S600, downshift to a lower stage, and repeat the subsequent process. do.

The P1/P2 type parallel hybrid system has relatively superior power efficiency and mechanical efficiency during regenerative braking compared to the existing P0/P2 method using a mechanical element called a belt-pulley. However, the existing regenerative braking method that generates power only with the P2 motor during regenerative braking has a problem in that it is difficult to cope with a situation where fast charging is required because the remaining amount of the battery drops to a dangerous level due to rapid battery exhaustion.

On the other hand, according to the embodiment of the present invention, when a situation in which the SOC is suddenly insufficient occurs, regenerative braking occurs not only in the P2 motor but also in the P1 motor by the engine clutch control and the shift stage control. Compared to technology, the amount of regenerative braking can be greatly increased, and as a result, it is possible to quickly respond to a situation in which the SOC drops sharply due to a sudden increase in load.

In addition, as the amount of regenerative braking is increased, a fuel efficiency improvement effect can be expected, thereby greatly improving the marketability and competitiveness of the vehicle.

In the above detailed description of the present invention, only specific embodiments thereof have been described. However, it is to be understood that the present invention is not limited to the particular form recited in the detailed description, but rather, it is to be understood to cover all modifications and equivalents and substitutions falling within the spirit and scope of the invention as defined by the appended claims. should be

10 : engine
20: clutch
30: gearbox
40: EMS (Engine Management System) controller
50: BMS (Battery Management System) controller
60: HCU (Hybrid Control Unit)
70: TMS (Transmission Management System) controller
P1: P1 motor
P2: P2 motor

Claims (10)

An engine, an engine clutch, and a transmission are arranged in a line, and a P1 motor is provided between the engine clutch and the engine to transmit and receive power to an output shaft of the engine, and a P2 motor is disposed between the engine clutch and the transmission on an input shaft of the transmission. In a hybrid vehicle equipped to transmit and receive power,
(a) determining whether the SOC requires fast charging;
(b) determining whether the vehicle is in an EV mode in which the vehicle is currently driven only by the output of the P2 motor if the SOC requires fast charging;
(c) requesting engine start if the SOC requires fast charging and the vehicle is currently driving in EV mode;
(d) increasing the rotation speed of the P1 motor to the rotation speed of the P2 motor together with the engine starting according to the engine start request;
(e) determining whether the rotation speeds of the P1 motor and the engine satisfy a predetermined condition;
(f) requesting a downshift to a lower gear than the current gear when the predetermined condition is satisfied; and
(g) slip control of the engine clutch to use the kinetic energy transmitted from the vehicle wheels according to the downshift as energy for regenerative braking of the P1 motor as well as the second motor. A method for controlling regenerative braking of a hybrid vehicle.
The method of claim 1,
In the step (a), when the SOC is less than the preset set value (A), the regenerative braking control method of the P1/P2 type parallel hybrid vehicle is determined as a situation in which fast charging is required.
The method of claim 1,
In step (e),
If the rotation speed of the P1 motor rotating by the engine output is the same as the rotation speed of the P2 motor and the difference between the engine rotation speed and the rotation speed of the P1 motor is less than a certain value, it is determined that the predetermined condition is satisfied. A method for controlling regenerative braking of a type hybrid vehicle.
The method of claim 1,
(h) monitoring the SOC in real time after step (g), and determining whether to switch the engine clutch control or request a downshift to a lower stage according to the monitoring result; P1/P2 type parallel hybrid vehicle further comprising of regenerative braking control method.
5. The method of claim 4,
In step (h), after the engine clutch slip control through step (g), it is monitored in real time whether the SOC reaches the preset value (B), and when the SOC reaches the set value (B), the engine clutch is removed from slip Regenerative braking control method of P1/P2 type parallel hybrid vehicle that switches to close.
6. The method of claim 5,
If the SOC does not reach the set value (B) after a certain period of time, it returns to step (f), requests a downshift to a lower stage, and then repeats the subsequent process for regeneration of the P1/P2 type parallel hybrid vehicle Brake control method.
An engine, an engine clutch, and a transmission are arranged in a line, and a P1 motor is provided between the engine clutch and the engine to transmit and receive power to an output shaft of the engine, and a P2 motor is disposed between the engine clutch and the transmission on an input shaft of the transmission. In a hybrid vehicle equipped to transmit and receive power,
an EMS controller for controlling the engine start on/off and output;
a BMS controller that supplies power to the P1 motor and the P2 motor or controls charging/discharging of a high voltage battery charged by the P1 motor and the P2 motor;
a hybrid control unit (HCU) for controlling the speeds of the P1 motor and the P2 motor; and
It includes; the EMS controller and the BMS controller, and a TMS controller for controlling the shift stage and the engine clutch of the transmission in cooperation with the HCU,
The TMS controller requests the EMS controller to start the engine, and after starting the engine, the TMS controller requests the EMS controller to start the engine when the SOC of the high-voltage battery falls below the set value (A) and fast charging is required and the current vehicle driving mode is the EV mode. A regenerative braking control device for a P1/P2 type parallel hybrid vehicle that performs slip control of the engine clutch along with downshifting when the state satisfies a predetermined condition.
8. The method of claim 7,
When the SOC of the high voltage battery falls below the set value (A), the BMS controller determines that fast charging is required, and transmits a fast charging request signal to the TMS controller,
The TMS controller analyzes the HCU and EMS controller signals at the time when the fast charging request signal is received and determines whether the vehicle is in an EV mode in which the vehicle is currently driven only by the output of the P2 motor,
When the vehicle is currently driving in EV mode, it requests the engine start to the EMS controller and at the same time makes a request to increase the engine output so that the rotation speed of the P1 motor rises to the rotation speed of the P2 motor,
When the rotation speed of the P1 motor rotating at the engine output is the same as the rotation speed of the P2 motor and the difference between the engine rotation speed and the rotation speed of the P1 motor is less than or equal to a certain value, in response to a request to start the engine and increase the engine output, the predetermined condition A regenerative braking control device for a P1/P2 type parallel hybrid vehicle that determines that , is satisfied, and downshifts the shift stage to a lower stage than the current shift stage and at the same time controls the slip of the engine clutch.
9. The method of claim 8,
The TMS controller,
The SOC of the high voltage battery is monitored in real time in cooperation with the BMS controller in the engine clutch slip control state with the downshift execution, and when the SOC reaches the preset set value (B), the engine clutch is shifted from slip to closed state. Regenerative braking control device of P1/P2 type parallel hybrid vehicle that converts.
10. The method of claim 9,
If the SOC does not reach the set value (B) even after a certain period of time has elapsed during SOC monitoring, the TMS controller performs regenerative braking of a P1/P2 type parallel hybrid vehicle that performs control to downshift the shift stage to a lower stage controller.

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