JP2973797B2 - Hybrid electric vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid electric vehicle equipped with a motor and an engine driven generator.

[0002]

2. Description of the Related Art An electric vehicle is a vehicle driven by a motor, and its low pollution has attracted public attention. The driving power of the motor is supplied from a vehicle-mounted main battery (for example, a rechargeable battery such as a lead battery). As an electric vehicle, a configuration in which an engine-driven generator is mounted in addition to a main battery as a power source of a motor, that is, a hybrid electric vehicle is known.

In a hybrid electric vehicle called a series hybrid electric vehicle, the power output of an engine-driven generator is used for driving a motor and charging a main battery. An engine-driven generator is a device composed of an engine and a generator. When the generator is driven by the engine, a power generation output is obtained from the generator,
The motor is driven or the main battery is charged by this power generation output.

Japanese Patent Application Laid-Open No. 4-29504 discloses a configuration for controlling an engine-driven generator in accordance with the state of charge (SOC) of a main battery. As described above, the power output of the engine-driven generator can be used not only for driving the motor but also for charging the main battery. For example, by performing on / off control of the engine according to the SOC of the main battery, The SOC of the battery can be managed to a suitable value. This contributes to prevention of overcharging and insufficient charging of the main battery and, consequently, to prolonging its life.

[0005]

As described above, a hybrid electric vehicle requires a controller for controlling the engine and the generator in addition to the control (vehicle control) relating to the output of the motor. Power is supplied to this type of controller from the auxiliary battery instead of the main battery described above. That is, an auxiliary battery that supplies a low voltage of, for example, about 12 V is mounted on a vehicle, and each controller operates with a power supply voltage supplied from the auxiliary battery. In addition to the controller, the auxiliary battery also supplies power to various on-vehicle auxiliary equipment and an engine starter.

In such a configuration, if an attempt is made to start the engine while vehicle control is being performed, the voltage of the auxiliary battery may decrease due to the starter load, and the power supply voltage of each controller may decrease. If such a drop in the power supply voltage becomes remarkable, malfunction of each controller may occur, control may become unstable, and the motor speed may fluctuate.

In order to prevent such a problem, the power supply of each controller and the power supply of the starter may be provided separately. However, such a configuration requires the addition of a starter power supply, which leads to an increase in cost and Problems such as an increase in weight occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a structure in which power is supplied from a single auxiliary battery to each control member and an engine starting motor. It is an object of the present invention to provide a hybrid electric vehicle that prevents a decrease in the power supply voltage of a control member due to starting, thereby reducing the possibility of occurrence of a problem such as a change in the motor rotation speed due to a malfunction, and that is preferable in terms of cost and weight. Aim.

[0009]

In order to achieve the above object, a hybrid electric vehicle according to a first configuration of the present invention comprises a motor as a driving source of a vehicle and a generator for generating driving power for the vehicle. And an engine that is started by the attached starter motor and drives the generator, and the engine is started by operating the starter motor in response to the power generation request,
In a hybrid vehicle including a control member that controls power supply to a motor and an auxiliary battery that supplies power to at least the control member and a starting motor, the control member controls power supply to the motor when a power generation request occurs. In this state, the starting of the engine by the starting motor is prohibited.

A hybrid electric vehicle according to a second configuration of the present invention is characterized in that control of power supply to the motor is stopped in response to generation of a power generation request and restarted after the engine is started.

In the hybrid electric vehicle according to the third configuration of the present invention, the control and restart of the power supply to the motor in the second configuration are executed by shutting off and supplying power to at least a part of the control member. It is characterized by.

[0012]

In the hybrid electric vehicle according to the first aspect of the present invention, if a power generation request is issued while the control member is controlling the power supply to the motor, the power generation request is generated even though the power generation request is generated. The starting of the engine with respect to the starting motor is prohibited. Therefore, since a decrease in the power supply voltage of the control member due to the operation of the starting motor is prevented from affecting the control of the vehicle output, a malfunction of the control member due to the decrease in the power supply voltage is prevented. Also, unlike the configuration in which a separate power supply is added, no increase in weight or cost is caused.

Further, in the hybrid electric vehicle according to the second configuration of the present invention, when a power generation request is generated, the control of the power supply to the motor is stopped and restarted after the engine is started. Therefore, at the time when the control member operates the starting motor to start the engine, the control member does not control the power supply to the motor by the control member.
Even if the power supply voltage of the control member drops, the content of the control of the power supply to the motor does not become erroneous. Therefore, also in this configuration, the same operation as in the first configuration occurs.

[0014] In the hybrid electric vehicle according to the third configuration of the present invention, the control and restart of the power supply to the motor in the second configuration are executed by shutting off and supplying power to at least a part of the control member. . Therefore, also in this configuration, the same operation as in the second configuration occurs.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a system configuration of a hybrid electric vehicle according to one embodiment of the present invention. The electric vehicle shown in this figure uses a motor 10 configured as, for example, a three-phase AC induction motor as a drive source. That is, when the motor 10 is driven, its output is
Is transmitted to the vehicle and becomes the driving force of the vehicle.

As a power source of the motor 10, in addition to an engine-driven generator described later, a main battery 14 configured as a lead battery or the like is mounted. The main battery 14 is connected to an input side of an inverter 18 via a main relay 16, and an output side of the inverter 18 is connected to the motor 10. The inverter 18 converts the discharge power of the main battery 14 into three-phase AC power under the control of a vehicle controller 20 described later, and supplies the three-phase AC power to the motor 10.

An engine-driven generator, which is another drive power source of the motor 10, includes an engine 22 and a generator 24. The mechanical output of the engine 22 is
As a result, the number of revolutions is increased to a level suitable for driving the generator 24, and the generator 24 is rotationally driven by the output of the speed increaser 26. Therefore, when a field current is supplied to the generator 24 while the engine 22 is operating, a power generation output is obtained from the generator 24. In this figure, the generator 24
Is configured as a three-phase AC generator, the output of which is rectified by a rectifier
Supplied to Therefore, the power output of the generator 24 can be used not only for driving the motor 10 via the inverter 18 but also for charging the main battery 14 as well as the discharge power of the main battery 14.

As means for controlling such a driving mechanism, a vehicle controller 20, a generator controller 30 and an engine controller 32 are provided in this figure. The vehicle controller 20 inputs a vehicle signal, for example, an accelerator signal indicating an accelerator operation of a vehicle operator, a brake signal indicating a brake operation, an IG signal indicating a state of an ignition switch (IG), a vehicle speed signal indicating a vehicle speed, and the like. On the other hand, the motor speed is input from a speed sensor 34 attached to the motor 10. The vehicle controller 20 controls the motor 10 by controlling the inverter 18 based on such information, for example, the accelerator signal and the motor speed, so that an output corresponding to the accelerator operation of the vehicle operator can be obtained (vehicle). control).

The vehicle controller 20 gives commands to the engine controller 32 and the generator controller 30,
Alternatively, the operation of the engine-driven generator is controlled while transmitting and receiving information. That is, the engine controller 32 and the generator controller 30 control the corresponding engine 22 or generator 24 while exchanging signals with the vehicle controller 20.

The vehicle controller 20 controls the operation of the main relay 16 and the starter 36 in addition to the vehicle control and the control of the engine 22 and the generator 24. That is, the main relay 16 is opened and closed by exciting the main relay coil 38, thereby opening and closing the connection between the main battery 14 and the inverter 18 and the rectifier 28. Further, the vehicle controller 20 turns on / off the starter relay 42 by exciting the starter coil 40, and turns on / off the power supply from the auxiliary battery 44 to the starter 36. The auxiliary battery 44 is an on-vehicle battery, and is used to supply power to not-shown in-vehicle electrical accessories in addition to the vehicle controller 20, the generator controller 30, the engine controller 32, the starter 36 and the inverter 18 shown in FIG. Voltage is being supplied.

FIG. 2 shows an operation flow of the vehicle controller 20 in this embodiment. The operation shown in this figure is a routine executed by the vehicle controller 20 at a predetermined frequency, particularly a routine related to the control of the starter 36.

In this figure, the vehicle controller 20
First determines whether or not a power generation request has been issued (10
0). That is, it is determined whether or not power generation is requested for the engine-driven generator. This request, for example,
Occurs when the vehicle operator turns on the IG at the start or when the SOC of the main battery 14 decreases.

When it is determined that a power generation request has occurred,
Subsequently, the vehicle controller 20 determines whether the vehicle is running (102). This determination is made by, for example, the rotation speed sensor 3
The determination is made as to whether or not the value of the motor speed detected by step 4 or the vehicle speed signal input as the vehicle signal is equal to or greater than a predetermined value. If the result of this determination is that the vehicle is not running, the vehicle controller 20 excites the starter coil 40 and turns on the starter 36 (10
4). On the other hand, if it is determined that the vehicle is not running, the process returns to step 100.

If it is determined in step 100 that a power generation request has not been issued, the vehicle controller 20 turns off the starter 36 by controlling the starter relay 42 (106). After that, the vehicle controller 20
It is determined whether or not any abnormality has occurred in each part of the vehicle (diag check) (108). As a result, if any abnormality has occurred, predetermined error processing is executed, and no abnormality has occurred. If not, the process returns to the main routine.

Therefore, when the vehicle operator starts the IG with the vehicle stopped, step 104 is executed and the starter 36 is turned on. When the starter 36 is turned on, the engine 22 is thereby started, and power generation by the engine-driven generator is started.

If the engine 22 stops due to an accident such as running out of fuel while the vehicle is running, the starter 36 is not turned on because the vehicle is running even if the vehicle operator starts the IG after the accident is resolved. Thereafter, when the vehicle stops (when the number of revolutions of the motor 10 is significantly reduced or the vehicle speed is significantly reduced), the starter 36 is turned on for the first time at that time. Therefore, the vehicle controller 20 controls the inverter 18 (vehicle control).
Since the starter 36 is not turned on in the state of performing the operation, the auxiliary battery 44
Does not cause the malfunction of the vehicle controller 20 or the like. Further, since there is no need to provide a power supply dedicated to the starter 36, there is no increase in vehicle weight or cost.

FIG. 3 shows the flow of a hybrid electric vehicle according to a second embodiment of the present invention. This embodiment can be implemented in the system shown in FIG.

In this embodiment, first, step 1
00 is executed, the vehicle controller 20 determines whether or not the engine 22 is stopped (1).
10). This determination is executed, for example, as a determination as to whether or not the engine speed is equal to or less than the starter 36 drive speed. The engine speed used for this determination is determined from the target value of the power generation output and the like. If it is determined that the engine 22 is stopped, the vehicle controller 20 stops the vehicle control, that is, the output control of the motor 10 by the inverter 18 (112). After that, the vehicle controller 20 executes step 104 and returns to step 100. If the determination conditions in steps 100 and 110 are not satisfied, the vehicle controller 20 executes steps 106 and 108, restarts the vehicle control in the subsequent step 114, and then returns to the main routine.

Therefore, in this embodiment, when the engine 22 is stopped, for example, the IG
Is started, the vehicle control is temporarily stopped, and then the starter 36 starts the engine 22.
When the engine 22 is started, the vehicle control is started accordingly.

When the engine is stopped while the vehicle is running and the vehicle operator turns on the IG accordingly, the vehicle control is stopped and the engine 22 is started before the starter 36 is turned on. Later, the vehicle control is restarted. Therefore, the starter 36 is not turned on at the time when the vehicle control is being performed by the vehicle controller 20, so that there is no problem such as a change in the motor speed due to a malfunction in the vehicle control. Further, there is no increase in weight or cost due to the provision of a power supply dedicated to the starter 36. Further, when an induction motor is used as the motor 10, even if the vehicle control is stopped, the vehicle is in a coasting state, so that there is almost no problem associated with the temporary stop of the vehicle control.

The vehicle control in the second embodiment is stopped, for example, by turning off the main relay 16 to disconnect the main battery 14 from the inverter 18 or by shutting off all the switching elements constituting the inverter 18 at once. The control can be executed by giving a command from the vehicle controller 20 to the inverter 18 or by cutting off the power supply to a part of the vehicle controller 20 that directly controls the inverter 18.

[0033]

As described above, according to the first configuration of the present invention, when the vehicle control is being performed at the time when the power generation request is generated, the starting of the engine by the starting motor is prohibited. Therefore, a malfunction of the control member caused by operating the starting motor does not occur, so that a more stable device can be obtained. Further, there is no increase in vehicle weight or cost.

According to the second configuration of the present invention, the vehicle control is stopped in response to the generation of the power generation request and restarted after the engine is started, so that the same effect can be obtained.

According to the third configuration of the present invention, the stop and restart of the vehicle control are executed by shutting off and supplying power to at least a part of the control member. Can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration of a hybrid electric vehicle according to one embodiment of the present invention.

FIG. 2 is a flowchart showing an operation flow of the hybrid electric vehicle according to the first embodiment of the present invention.

FIG. 3 is a flowchart illustrating a flow of a hybrid electric vehicle according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 motor 14 main battery 16 main relay 18 inverter 20 vehicle controller 22 engine 24 generator 32 engine controller 36 starter 38 main relay coil 40 starter coil 42 starter relay 44 auxiliary battery

Claims (3)

(57) [Claims] 1. A motor which is a driving source of a vehicle, a generator for generating driving power for the vehicle, an engine which is started by an attached starting motor to drive the generator, and operates the starting motor in response to a power generation request. A hybrid electric vehicle including a control member that controls power supply to the motor and an auxiliary battery that supplies power to at least the control member and the starting motor while the engine is being started. A hybrid electric vehicle that prohibits starting of an engine by a starting motor when a control member controls power supply to the motor. 2. A motor that is a driving source of a vehicle, a generator that generates driving power for the vehicle, an engine that is started by an attached starting motor to drive the generator, and operates the starting motor in response to a power generation request. A hybrid electric vehicle including a control member for controlling power supply to the motor and an auxiliary battery for supplying power to at least the control member and the starter motor while the engine is started. A hybrid electric vehicle in which control of power supply to the vehicle is stopped and restarted after the engine is started. 3. The hybrid electric vehicle according to claim 2, wherein the control of the power supply to the motor is stopped and restarted by shutting off and supplying power to at least a part of the control member. .