KR20190068211A - Method for Running Hold with Fail-Safe Condition and Hybrid Electric Vehicle thereof - Google Patents

Abstract

According to the present invention, a method for maintaining fail-safe driving realizes limp groove control for using a counter electromotive force of a hybrid starter & generator (HSG) (5) and a drive motor (3) generated by operation of an engine (2) in maintaining a battery voltage of a low voltage direct current/direct current converter (LDC) (8) and operating a turbocharger (2-1) when a main relay is off by a failure of any one among the turbocharger (2-1), the drive motor (3), the HSG (5), and a high-voltage battery (6). Therefore, a hybrid electric vehicle (1) does not create intake resistance in the engine (2) by maintaining operation of the turbocharger (2-1) using the counter electromotive force even in a situation where the main relay is off by a failure of a high-power part. Specifically, the LDC (8) maintains a voltage of 12 V of an auxiliary battery (7) by the counter electromotive force to prevent discharging of the auxiliary battery (7) even when high-voltage power cannot be used.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a fail-safe driving method and a hybrid vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a running control of a vehicle, and more particularly, to a hybrid vehicle in which a fail-safe strategy is performed by driving a limp home of an engine in the event of a failure of a high-power component (PowerTrain Electric Device).

Generally, an electric turbo charger rotates with an electric motor irrespective of the number of revolutions of the engine, thereby solving the disadvantage of a mechanical turbocharger that rotates according to the number of revolutions of the engine. For example, an electric turbocharger simplifies the structurally complicated layout of a mechanical turbocharger, eliminating the boosting delay, especially due to engine speed, and the fuel efficiency drop due to backpressure in the high-rev range.

An example of a vehicle that utilizes the advantages of the electric turbo charger is a hybrid electric vehicle that is divided into a parallel type, a series type, or a mild type as a power transmission structure. In the hybrid electric vehicle, In the case of a parallel hybrid vehicle, a high-voltage main battery, a secondary battery, and a low-voltage direct current / direct current converter (LDC) constitute a power system, and a high-voltage electric turbocharger associated with the engine supplies the necessary high voltage. , A drive motor, a battery, and a hybrid starter & generator (HSG)).

Therefore, the parallel type hybrid vehicle can operate the vehicle utilizing the advantage of the electric turbocharger which does not cause the boosting delay and the fuel consumption deterioration problem, and the advantage of the layout configuration in the dynamometer passing power system is realized.

Japanese Laid-Open Patent Publication No. 2015-182576 (Oct. 22, 2015)

However, the relay logic due to the failure of the high-power component will affect the engine and the battery by short-circuiting the main relay of the high-voltage main battery after the engine is started.

For example, the engine impact is due to the intake resistance of the engine, which causes the power supply of the electric turbocharger, which uses a high voltage as the main relay short of the high voltage main battery, to stop operating under engine operation, .

For example, the battery impact is a short-time discharge of the 12V auxiliary battery, which limits the high voltage power to the main relay short circuit of the high voltage main battery and can not charge the 12V auxiliary battery of the LDC using the high voltage power, This is caused by the rapid discharge due to the use of the auxiliary battery.

According to the present invention, when the main relay OFF condition occurs after the vehicle is started and allowed to run, the limp home control of the engine by the back electromotive force of the HSG and the driving motor is used as a fail safe strategy, The turbocharger idle speed control which minimizes the intake resistance of the turbocharger in the limited power condition of the back electromotive force through the limp home control and the maintenance of the voltage of the auxiliary battery by the LDC control, The present invention is directed to a fail safe driving method and a hybrid vehicle.

In order to accomplish the above object, the present invention provides a fail-safe running maintenance method, wherein a limp-home control by a limp-home controller is performed when a main relay in which a high-power component and an electric circuit for supplying electric power are formed, The turbocharger operation is performed with the battery voltage maintained by the counter electromotive force, and the battery voltage maintenance takes priority over the operation of the turbocharger.

In a preferred embodiment, the high-power component comprises a turbocharger that sends compressed air to the engine, a drive motor that generates power with the engine, an HSG associated with the engine, an electric oil pump associated with the ISG of the engine, Which is one of the batteries to be supplied.

In a preferred embodiment, the driving motor and the HSG generate the counter electromotive force. The short circuit is the OFF state of the main relay. The OFF state is generated by the main relay OFF signal of the limp home controller, and the main relay OFF signal is generated when the high power component fails.

(A) a step of outputting a main relay OFF signal of the main relay according to a failure of the high-power component among the vehicle running information detected by the limp home controller, (B) (C) monitoring the voltage of the auxiliary battery requiring maintenance of the battery voltage; (D) maintaining the battery voltage and the turbocharger operation (E) controlling the charging of the battery of the LDC and the ON / OFF control of the turbocharger to maintain the battery voltage at the voltage judgment; (F) And the number of revolutions is controlled by the idle idles.

In a preferred embodiment, in the limp home control, the engine is operated at an increased number of revolutions relative to the upshift or downshift of the shift map.

In a preferred embodiment, in the limp-home control, the voltage determination is performed by applying a maximum value and a minimum value of the auxiliary battery to a detection voltage value of the voltage monitoring, and applying the minimum value after applying the maximum value. If the detected voltage value is smaller than the maximum value but smaller than the minimum value, the battery charge control by the LDC is performed while the turbocharger is maintained in the OFF control. On the other hand, if the detected voltage value is larger than the maximum value or smaller than the maximum value but larger than the minimum value, the turbocharger is switched from the OFF control to the ON control to operate the turbocharger.

In order to accomplish the above object, the hybrid vehicle of the present invention electrically connects a high-voltage main battery connected to an auxiliary battery to an LDC, and includes a turbocharger, a driving motor, and an HSG that are supplied with power from the high- High power components made up of components; The engine is operated to generate a counter electromotive force at the driving motor and the HSG when the main relay is turned off, and limp home control is performed in which the counter electromotive force is used for battery charging control of the auxiliary battery and ON / OFF control of the turbocharger A lymphatic home controller; Is included.

In a preferred embodiment, the OFF state of the main relay occurs when the high-power component fails.

In a preferred embodiment, the limp home controller is associated with a failure state shift map and a limp home map, and the failure state shift map raises the engine speed to the upshift or downshift of the shift map at the time of the limp home control And the lymph home map performs the battery charge control in conjunction with the LDC when the turbocharger is turned off.

In a preferred embodiment, the limp home controller preferentially uses the counter electromotive force to maintain the voltage of the auxiliary battery.

The hybrid vehicle of the present invention realizes the following actions and effects by driving the vehicle using the counter electromotive force according to the engine driving in the main relay OFF state.

First, safety of the vehicle and the consumer can be ensured by allowing the vehicle to continue to run even when the vehicle is unable to travel due to the failure of the high-power component occurring after the start-up and running. Second, the utilization of the back electromotive force of the HSG and the driving motor is the same as that of the high power use component failure situation even in the main relay off request state of each controller, so that the vehicle and the consumer are secured even in a wider vehicle situation. Third, by driving the engine to a limp home, the running control is performed by using the HSG, which is a high power consuming part, and the back electromotive force of the driving motor. Fourth, the idle control of the electric turbocharger during the limp home running of the engine eliminates the engine influence by the turbocharger acting as a resistance to the intake of the engine. Fifth, limp home and auxiliary battery discharge prevention control can be simultaneously performed by using the back electromotive force of the HSG and the driving motor in the auxiliary battery control of the LDC together with the idle control of the electric turbocharger. Sixth, since the counter electromotive force voltage is formed to be high in relation to the number of revolutions of the electric motor, it can be more effectively applied to a parallel type hybrid vehicle that increases the number of revolutions of the engine with a shift map in which the normal state and failure situation of the fixed gear ratio transmission are different.

FIG. 1 is a flow chart of a fail-safe travel maintenance method according to the present invention, FIG. 2 is an example of a vehicle in which limp-groove control is implemented as a fail-safe travel retention strategy according to the present invention, FIG. 4 is an example of a modified fixed state shift map in a main relay OFF condition using a shift map of a vehicle according to an embodiment of the present invention, FIG. 5 is an example of a fixed state shift map, This is an example of ON / OFF control of the turbocharger used.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which illustrate exemplary embodiments of the present invention. The present invention is not limited to these embodiments.

Referring to FIG. 1, in the failure-safe running maintenance method, a main relay OFF determination (S20) by a failure of a PowerTrain electric component is performed and a transition is made from a system normal control (S40) to an engine limp home control , The engine limb groove control (S30) uses the HSG generated by the engine connected with the HSG (Hybrid Starter & Generator) and the counter electromotive force of the motor to prevent the secondary battery discharge, And the minimum operation of the engine is maintained by performing the operation (S31 to S37).

As a result, the high-power component linking method of the fail-safe driving maintenance method can be applied to a case where even when the hybrid vehicle can be started and traveled, even when the main relay is turned on / off due to a failure of the PowerTrain Electric component, The strategy minimizes the turbocharger stall, which acts as an intake resistance to the engine, while also preventing secondary battery discharge.

Referring to FIG. 2, the hybrid vehicle 1 includes a dynamometer (PowerTrain) and a high-power component (PowerTrain Electric Device) connected by a mechanical link and an electronic link, a high- And a limp home controller 10 in which a fail-safe strategy is performed by a limp home control for a city dynamometer. In this case, the distinction between the dynamometer and the high-power component is described as an example.

Specifically, the dynamometer includes an engine 2 of an internal combustion engine, an electric drive motor 3, and a transmission 4. The engine 2 and the drive motor 3 are connected to each other by an engine clutch 3 - 3. The engine 2 is connected to an electric high voltage turbocharger 2 - 1 for compressing intake air and a HSG 5, And the drive motor 3 is connected to the transmission 4. The transmission 4 is provided with an electric oil pump (EOP) functioning for an ISG (Idle Stop & Go) function, .

Specifically, the high-power component includes a turbocharger 2-1, batteries 6 and 7, a drive motor 3, an HSG 5, and an electric oil pump. In this case, the batteries 6 and 7 are divided into a high voltage main battery 6 and a 12V auxiliary battery 7, and the high voltage main battery 6 and the auxiliary battery 7 are connected to an LDC (Low Voltage Direct Current / Direct Current Converter (8).

Therefore, the mechanical link connects the engine 2, the HSG 5, the drive motor 3 and the transmission 4, and the electronic link connects the turbocharger 6 of the high- The connection to the drive motor 3, the HSG 5, the EOP and the LDC 8 and the connection of the auxiliary battery 7 to the LDC 8. In particular, the main relay 9 (see FIG. 5) is included in the electronic link between the high voltage main battery 6 and the LDC 8.

Specifically, the limp home controller 10 processes the vehicle information according to the traveling of the hybrid vehicle 1 as input data, outputs a main relay OFF signal when detecting failure information of a high-power component while performing system normal control, (10-1) and the limp home map (10-2) in accordance with the fail-safe strategy when the main relay (9) is turned off, .

For example, the vehicle information includes the engine / motor revolution speed, the speed change stage, the battery voltage, the SOC, the turbocharger / HSG ON / OFF, and the ISG ON / OFF. The configuration for these detection information is the same as that of a conventional hybrid vehicle Do. The system normal control means a normal vehicle control state in which the turbocharger 2-1 is operated by receiving the current of the high voltage main battery 6. The engine limb groove control is performed by the turbocharger 2-1 which is not supplied with the current of the main battery 6 and the driving motor 3 and the HSG 5). ≪ / RTI >

For example, the failure state shift map 10-1 indicates that the limp home controller 10 controls the upshift and the upshift in the normal situation of the normal shift map such that the revolution speed of the engine 2 is kept high, So that the downshift can be performed at a high vehicle speed. The limp home map 10-2 is configured such that the limp home controller 10 prevents the LDC 8 from discharging the auxiliary battery 7 due to the back electromotive force of the drive motor 3 and the HSG 5 So as to control the operating condition of the turbocharger (2-1) which is not supplied with the current of the high voltage main battery (6).

In particular, the limp home controller 10 implements the logic in consideration of the following conditions in utilizing the back electromotive force of the driving motor 3 and the HSG 5. First, the voltage relationship between the power components has the following relationship. The internal component burnout voltage A of the power system inverter (e.g., Insulated Gate Bipolar Transistor) including the LDC 8, the operating voltage B of the turbocharger 2-1, and the auxiliary battery 7, The charging voltage C of the driving motor 3 and the HSG 5 is in a relation of A> C> B, and the counter electromotive force of the driving motor 3 and the HSG 5 does not deviate from A. "A> C> B" indicates that A is a value larger than C and C is a value larger than B. Here, ">" is an inequality indicating the magnitude of two values. Second, the use of counter-electromotive force has the following relationship. For example, when the back electromotive force of the drive motor 3 and the HSG 5 is supplied to the turbocharger 2-1, the EOP and the LDC 8 at the operating voltage, the turbocharger 2-1 is driven A phenomenon that leads to a low voltage of 12V of the auxiliary battery 7 occurs for an unoccupied operating voltage of the LDC 8 to be operated and a limited power of the counter electromotive force is applied to the turbocharger 2- (2-1) for turning on / off the LDC (8).

Hereinafter, the fail-safe running maintenance method will be described in detail with reference to FIG. 2 to FIG. In this case, the control subject is the limp home controller 10 associated with the failure state shift map 10-1 and the limp home map 10-2, and the controlled object is the engine 2, the turbocharger 2-1, HSG 5 and LDC 8.

The limp home controller 10 performs the vehicle traveling information detecting step of S10 and the main relay OFF switching step of S20.

2, the limp home controller 10 includes a high voltage main battery 6, a supplementary battery 7, a drive motor 3, and HSG (Power Train Electric Parts), which are power train electric parts, together with vehicle information detected by the hybrid vehicle 1. [ (I.e., a high-power component state) for each of the power components 5, and detects a failure of the PowerTrain Electric component from the PE component state, and then generates an ON to OFF switching signal of the main relay 9 . As a result, the main relay 9, which has connected the high voltage main battery 6 and the LDC 8 with the ON signal of the main relay 9, is short-circuited to the OFF switching signal of the main relay 9, The system steady state control of S40 is switched to the engine limp home control of S30.

3, the operation of the turbocharger 2-1 and the generation of the counter electromotive force for charging the auxiliary battery 7 are controlled by the turbocharger 2-1 and the high voltage main battery 6, Bringing an electric short of. The controller 10 switches to the operating state of the engine 2 temporarily by the HSG 5 so that the HSG 5 and the drive motor 3 held in the engine 2 generate a counter electromotive force corresponding to the number of revolutions , The counter electromotive force is controlled by the LDC 8 operating as an inverter. In this case, the counter electromotive force control of the inverter first applies the LDC operation guarantee control if the back electromotive force voltage is lower than the minimum operation voltage of the electric turbo charger 2-1 of high voltage so that EOP operation and control of high voltage are impossible.

Then, the limp home controller 10 performs the engine limp home control of S30 in the engine start control execution step of S31, the fixed state shift map switching step of S32, the auxiliary battery voltage monitoring step of S33, the maximum value determination of the auxiliary battery voltage of S34 , The step S35 for determining the auxiliary battery voltage minimum value, the step S36 for maintaining the turbocharger OFF, the step S37 for switching on the turbocharger, and the step S37-1 for maintaining the turbocharger idle.

Specifically, in step S31, the engine start control is performed in step S32. In step S32, the limp home controller 10 transmits an engine start signal to the HSG 5 so that the engine 2 is operated by the HSG 5 And shifts the normal upshift (or downshift) to the upshift (or downshift) of the failure state through the failure state shift map 10-1.

Referring to Fig. 4, the shift map applied to the transmission 4 is changed to the upshift (or downshift) of the failure situation by the failure state shift map 10-1. In this speed change control, not only the engine speed of the engine 2 but also the motor speed of the drive motor 3 is kept high, and the rotation of the high engine and the drive motor forms a high back electromotive voltage with a back electromotive force proportional to the rotation speed, Thereby contributing to the formation of a possible voltage capable of operating the electric turbo charger 2-1.

More specifically, in the step S33 for monitoring the auxiliary battery voltage, the step S34 for determining the auxiliary battery voltage maximum value, and the step S35 for determining the auxiliary battery voltage minimum value, the limp home controller 10 determines whether the auxiliary battery 7 A threshold is applied to the detection voltage while monitoring the detection voltage to determine whether the auxiliary battery 7 is charged or not by applying the following equation.

Secondary battery voltage maximum value Judgment formula: Auxiliary battery voltage> A

Secondary battery voltage minimum value Judgment formula: Auxiliary battery voltage <B

Here, " auxiliary battery voltage " is the detection voltage of the auxiliary battery 7 at the determination time, and each of &quot; A &quot; and &quot; B " Is a minimum discharge prevention voltage value set to 12V-a, and &quot; a "is a predetermined voltage value allowed by the battery specification. Each of ">" and ">" is an inequality indicating the magnitude relationship of two values. "Auxiliary battery voltage> A" is a value greater than A, "Auxiliary battery voltage <B" It means a small value.

Therefore, the limp home controller 10 judges whether the current voltage of the auxiliary battery 7 is located between the maximum value and the minimum value by setting 12V + a of the auxiliary battery 7 as a maximum value and 12V-a as a minimum value. When the detected voltage of the auxiliary battery 7 is smaller than the maximum value (12V + a) and less than the minimum value (12V-a), the limp home controller 10 switches to the turbocharger OFF maintaining step of S36, And maintains the charger 2-1 in the OFF state. As a result, the auxiliary battery 7 prevents the short-time discharge phenomenon by the priority LDC operation guarantee control under the OFF condition of the main relay 9. [ This is because the turbocharger 2-1 is turned off because the back electromotive force is entirely used for charging the auxiliary battery 7 by the LDC 8. [

On the other hand, when the detection voltage of the auxiliary battery 7 is greater than the maximum value (12V + a) or greater than the minimum value (12V-a), the limp home controller 10 enters the turbo charger ON switching stage of S37.

Referring to FIG. 5, the limp home controller 10 monitors the voltage of the auxiliary battery 7 during the 12V voltage monitoring of the auxiliary battery 7 to reach a certain range of critical points (i.e., 12V + a and 12V-a) And on / off control for the charger 2-1 is performed. The limp home controller 10 stops the operation of the turbo charger 2-1 when the voltage of the auxiliary battery 7 of 12V falls below a predetermined value to cause the HSG 5 and the drive motor 3 The auxiliary battery 7 is charged by the control of the LDC 8. [ This preferential LDC operation guarantee control of the limp home controller 10 is performed by the discharge of the auxiliary battery 7 of 12V which should be prioritized in terms of the hybrid system by turning off the turbo charger 2-1, .

In particular, the limp home controller 10 controls the operation of the turbocharger 2-1 to the turbocharger idle step S37-1. This is because when the counter electromotive force formed by the HSG and the driving motor is not large, the auxiliary battery 7 is prevented from being completely discharged in a short period of time when all the counter electromotive force is used in the turbo charger 2-1. Therefore, the idle control of the turbocharger 2-1 can be performed by controlling the generated back electromotive voltage to be able to operate the turbocharger 2-1, but not boosting the torque of the engine 2, Thereby preventing the stopped state of the turbo charger 2-1 to be operated.

As a result, the limp home controller 10 simultaneously performs control to maintain the voltage of the auxiliary battery 7 within a certain range by the engine limp home control of the fail-safe strategy in response to the failure of the high-power component.

As described above, the fail-safe running maintenance method implemented by the limp home controller 10 of the hybrid vehicle 1 according to the present embodiment includes the turbocharger 2-1, the driving motor 3, the HSG 5, The back electromotive force of the drive motor 3 and the HSG 5 generated by the operation of the engine 2 when the main relay 9 is turned off due to the failure of the high power component is maintained in the battery voltage of the LDC 8 and the turbocharger 2-1 And the lumped groove control does not generate an intake resistance in the engine 2 due to the maintenance of the turbo charger 2-1 by the back electromotive force, and in particular, the LDC 8 is driven by the back electromotive force The voltage of the auxiliary battery 7 of 12V is maintained to prevent the discharge of the auxiliary battery 7 even when the high voltage power is not available.

1: hybrid vehicle 2: engine
2-1: Turbocharger 3: Driving motor
3-1: engine clutch 4: transmission
5: Hybrid Starter & Generator (HSG)
6: High voltage main battery 7: Auxiliary battery
8: LDC (Low Voltage Direct Current / Direct Current Converter)
9: main relay 10: lymph home controller
10-1: Failure situation shift map 10-2: lymph home map

Claims (17)

A limp home control is performed by a limp home controller at the time of short-circuiting of a main relay forming a high-power part (electric power device) and an electric circuit for power supply,
Wherein the limp home control is performed by driving the turbocharger with the battery voltage maintained by the counter electromotive force.
The fail safe running maintenance method according to claim 1, wherein the maintenance of the battery voltage takes priority over the operation of the turbocharger.
The fail safe driving maintenance method according to claim 1, wherein the high-power component is one of a turbocharger, a driving motor, a hybrid starter & generator (HSG), and a battery.
4. The fail safe driving maintenance method according to claim 3, wherein the driving motor and the HSG generate the counter electromotive force.
The fail safe running maintenance method according to claim 1, wherein the short circuit is the OFF state of the main relay.
The fail safe driving maintenance method according to claim 5, wherein the OFF state is generated by a main relay OFF signal of the controller, and the main relay OFF signal is generated when a high power component fails.
2. The method according to claim 1, wherein the limp groove control comprises: (A) a step of outputting a main relay OFF signal of the main relay according to a failure of the high-power part among the vehicle running information detected by the limp- (B) generating a counter electromotive force in the HSG and a driving motor by an operation of an engine by a hybrid starter and a generator, (C) monitoring a voltage of an auxiliary battery requiring maintenance of the battery voltage, (D) (E) a battery charging control of an LDC (Low Voltage Direct Current / Direct Current Converter) for maintaining the battery voltage by the voltage judgment, and a battery charging control of the turbocharger Step in which ON / OFF control is performed
Wherein the fail-safe running maintenance method is performed in the following manner.

The fail safe running maintenance method according to claim 7, wherein the engine is operated at an increased rotational speed relative to an upshift or a downshift of a shift map.
The fail safe driving maintenance method according to claim 7, wherein the voltage determination is performed by applying a maximum value and a minimum value of the auxiliary battery to a detection voltage value of the voltage monitoring.
The fail safe driving maintenance method according to claim 9, wherein the voltage determination is performed by applying the minimum value after applying the maximum value.
The fail safe driving maintenance method according to claim 10, wherein when the detected voltage value is smaller than the maximum value but less than the minimum value, the battery charge control is performed by the LDC while the turbocharger is maintained in the OFF control .
The turbocharger of claim 10, wherein when the detected voltage value is larger than the maximum value or smaller than the maximum value but larger than the minimum value, the turbocharger is switched from the OFF control to the ON control, Fail safe driving method.
[Claim 7] The method of claim 7, wherein the limp home control comprises: (F) controlling rotation speed of the turbocharger by idle
Wherein the fail safe running maintenance method comprises the steps of:
A turbocharger and a driving motor which form an electronic link with a high voltage main battery connected to a secondary battery by a low voltage direct current / direct current converter (LDC), power is supplied from the high voltage main battery to the main relay, Starter & generator) as a component (PowerTrain Electric Device);
The engine is operated to generate a counter electromotive force at the driving motor and the HSG when the main relay is turned off, and limp home control is performed in which the counter electromotive force is used for battery charging control of the auxiliary battery and ON / OFF control of the turbocharger A lymphatic home controller;
The hybrid vehicle comprising:
15. The hybrid vehicle of claim 14, wherein the OFF state of the main relay occurs when the high-power component fails.
15. The system of claim 14, wherein the limp home controller is associated with a fault situation shift map and a limp home map,
Wherein the failure state shift map raises the engine speed in response to an upshift or a downshift of the shift map during the limp home control and the limp home map is configured to control the battery charge control To the hybrid vehicle.
15. The hybrid vehicle as set forth in claim 14, wherein the maintenance of the auxiliary battery voltage of the limp home controller takes priority over the use of the counter electromotive force.

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