JP4983274B2 - Vehicle power supply device - Google Patents

Description

  The present invention relates to a power supply device for a vehicle that supplies power to an electrical system and a motor with a generator driven by an engine.

2. Description of the Related Art Conventionally, various configurations are known for a vehicle power supply device that supplies electric power to an electrical system and a motor with a generator driven by an engine (see, for example, Patent Document 1). FIG. 10 is a diagram for explaining a basic configuration of the above-described conventional vehicle power supply apparatus. In the example shown in FIG. 10, 101 is a generator driven by an engine (not shown), 102 is a relay circuit, 103 is an inverter, 104 is a motor, 105 is vehicle electrical equipment, 106 is a battery, The battery 106 constitutes an electrical system.
JP 2004-222443 A

  In the example shown in FIG. 10, electric power is supplied to the electrical system (vehicle electrical system 105 and battery 106) and the motor 104 with a single generator 101 driven by the engine. At that time, the case where power is supplied to the electrical system and the case where power is supplied to the motor 106 are switched by ON / OFF driving of the relay circuit 102. That is, when the motor 106 is driven, the relay circuit 102 is turned off and the inverter 103 is turned on. When the electrical system is driven, the relay circuit 102 is turned on and the inverter 103 is turned off.

  In the conventional vehicle power supply apparatus described above, a single generator 101 supplies power to two systems having different required voltages for driving a motor 104 and driving an electrical system (vehicle electrical system 105 and battery 106). It is structured to do. Therefore, the relay circuit 102 selectively selects driving of the motor 104 and driving of the electrical system to supply power, and as a result, while supplying power to the motor 104 and driving it, At the same time, there is a problem that power cannot be supplied to the battery 106 and the amount of discharge of the battery 106 increases.

  An object of the present invention is to solve the above-mentioned problems, and to provide a vehicle power supply device that can suppress the amount of battery discharge during motor driving and extend the life of the battery.

  The power supply device for a vehicle according to the present invention is a power supply device for a vehicle that supplies power to an electric system and a motor with a generator driven by an engine. The electric power system is connected in series downstream of the motor, A current bypass circuit is provided in parallel, and the voltage supplied to the electrical system is adjusted by controlling the current passing through the bypass circuit.

  In the vehicle power supply device of the present invention, the electrical system is connected in series downstream of the motor, and a current bypass circuit is provided in parallel with the electrical system, and the current passing through the bypass circuit is controlled to be supplied to the electrical system. By adjusting the voltage, the power can be supplied to both the motor and the electrical system with different required voltages at the same time, thereby reducing the amount of battery discharge while driving the motor and extending the battery life. Can do. In addition, when the voltage rises due to a sudden decrease in the electrical load, the power supply to the electrical system can be cut off immediately by passing a current through the bypass circuit. Voltage can be controlled more quickly than lowering.

  As a preferred example of the vehicle power supply device of the present invention, when the power generation capability of the generator is low and the power required for driving the motor cannot be supplied, the amount of current passing through the bypass circuit can be increased. . By comprising in this way, the electric power which has been supplied to the electrical system is reduced, and that amount can be used for motor driving. As a result, the driving force increases compared to the conventional case. In addition, since the electric power that has already been generated and supplied to the electrical system is supplied to the motor, when the required power of the motor rises rapidly, the electric power can be supplied faster than the operation of the generator with a delayed response.

  Furthermore, as a preferable example of the vehicle power supply device of the present invention, when a relay circuit is provided in parallel with the motor, the voltage required by the motor is low, and the voltage required by the vehicle electrical equipment in the electrical system is sufficient. The relay circuit is turned on so that the motor and the electrical system are connected in parallel, the voltage required by the vehicle electrical system is generated, and the generated power is supplied to both the motor and the electrical system simultaneously. When the motor is an AC motor, the motor output may be controlled by an inverter, and when the motor is a DC motor, the motor output may be controlled by a current flowing through a bypass circuit. With this configuration, if the motor is connected in series, current does not flow very much when the required power of the motor is small, so that less current is supplied to the electrical system. Even when it is small, power can be sufficiently supplied to the electrical system.

  Embodiments of a power supply device for a vehicle according to the present invention will be described below with reference to the drawings.

<About a four-wheel drive vehicle to which the vehicle power supply device of the present invention can be preferably applied>
FIG. 1 is a diagram for explaining an example of a four-wheel drive vehicle to which the vehicle power supply device of the present invention can be suitably applied. In the example shown in FIG. 1, the left and right front wheels 1 </ b> L and 1 </ b> R are main drive wheels that are driven by the engine 2 that is an internal combustion engine, and the left and right rear wheels 3 </ b> L and 3R are slave drive wheels that can be driven by the motor 4.

  The output torque Te of the engine 2 is transmitted to the left and right front wheels 1L, 1R through the transmission and the reference gear 5. Further, a part of the output torque Te of the engine 2 is transmitted to the generator 7 via the endless belt 6, so that the generator 7 has a rotation speed Ng obtained by multiplying the rotation speed Ne of the engine 2 by the pulley ratio. Rotate. The generator 7 becomes a load on the engine 2 in accordance with the field current Ifg adjusted by the 4WD controller 8, and generates power in accordance with the load torque. The magnitude of the power generated by the generator 7 is determined by the magnitude of the rotational speed Ng and the field current Ifg. The rotational speed Ng of the generator 7 can be calculated from the rotational speed Ne of the engine 2 based on the pulley ratio. The electric power generated by the generator 7 can be supplied to the motor 4 via the inverter 9. The drive shaft of the motor 4 can be connected to the rear wheels 3L and 3R via the speed reducer 11 and the clutch 12. The motor 4 in this example is an AC motor. Moreover, the code | symbol 13 in a figure shows a difference gear.

  Each wheel 1L, 1R, 3L, 3R is provided with a wheel speed sensor 27FL, 27FR, 27RL, 27RR. Each wheel speed sensor 27FL, 27FR, 27RL, 27RR outputs a pulse signal corresponding to the rotation speed of the corresponding wheel 1L, 1R, 3L, 3R to the 4WD controller 8 as a wheel speed detection value. The 4WD controller 8 includes an arithmetic processing unit such as a microcomputer, for example, and includes wheel speed signals detected by the wheel speed sensors 27FL to 27RR, an output signal of a resolver connected to the motor 4, and an accelerator pedal depression amount. Information such as the accelerator opening corresponding to is input.

  FIG. 2 is a circuit diagram for explaining an example of field control in the generator 7. In the example shown in FIG. 2, 7a is an armature coil of the generator 7, 7b is a field coil, 7c is a switching element, and 7d is a battery. Then, by controlling the field current Ifg flowing through the field coil 7b based on the PI control, the generated voltage value Vg of the generator 7 is controlled to be the target voltage value.

  In the above-described example, the vehicle power supply device of the present invention is applied to a four-wheel drive vehicle. However, it goes without saying that the vehicle power supply device of the present invention can also be applied to other generators. Absent.

<Description of Power Supply Device for Vehicle of the Present Invention>
Hereafter, the characteristic part of the electric power supply apparatus of the vehicle of this invention is demonstrated. FIG. 3 is a diagram for explaining the concept of an example of the vehicle power supply device of the present invention. In the example shown in FIG. 3, a load 32 equivalent to a motor and a load 33 equivalent to an electrical system (vehicle electrical equipment and a battery) are connected in series to a power source 31 equivalent to a generator, and a variable resistance equivalent to a bypass circuit. 34 and a load 33 are connected in parallel. With this configuration, even when the load 32 and the load 33 having different required voltages are connected in series, the variable resistor 34 is controlled when the necessary voltage is supplied to the load 32 from the power source 31 as a whole. Thus, the voltage of the load 33 can be set to a voltage necessary for the load 33. Therefore, power can be supplied to both the load 32 and the load 33 having different required voltages at the same time.

<Description of the first embodiment>
FIG. 4 is a view for explaining a first embodiment of the vehicle power supply apparatus of the present invention. In the example shown in FIG. 4, 41 is a generator driven by an engine (not shown), 42 is an inverter, 43 is a motor, 44 is vehicle electrical equipment, 45 is a battery, and the vehicle electrical equipment 44 and the battery 45 are vehicles. It constitutes the entire electrical system. In the example shown in FIG. 4, the vehicle power supply device of the present invention is characterized in that an electrical system (vehicle electrical system 44 and battery 45) is connected in series downstream of the motor 43, and the current in parallel with the electrical system. The bypass circuit 46 is provided. In the example shown in FIG. 4, an example is shown in which the bypass circuit 46 is configured by a switching element and a diode, but any circuit can be used as long as the flowing current can be controlled.

  In the first embodiment described above, the voltage (Vmot) applied to the motor 43 and the required motor voltage from the motor control unit 51 are supplied to the generator control unit 52 as shown in FIG. The control unit 52 performs feedback control. When Vmot is lower than the required voltage, the field current of the generator 41 is increased, and when Vmot is higher than the required voltage, the field current of the generator 41 is decreased, and the generator field DUTY is supplied to the generator 41. The generated voltage is controlled. Further, the battery voltage (Vbat) of the battery 45 and the battery target voltage are supplied to the bypass control unit 53, and the bypass control unit 53 performs feedback control. When Vbat is higher than the battery target voltage, the bypass current is increased. When Vbat is lower than the battery target voltage, the bypass current is decreased. The bypass circuit DUTY is supplied to the bypass circuit 46, and the current flows through the bypass circuit 46. Is controlling. The control for the battery 45 described above is the same for the other components constituting the electrical system, for example, the vehicle electrical system 44. As a result, power can be supplied to both the motor 43 and the electrical system (vehicle electrical equipment 44 and battery 45) having different required voltages at the same time.

  In the first embodiment of the present invention, as shown in another example of control in FIG. 6, when it is determined that the power generation capacity of the generator 41 is insufficient, that is, the power generation capacity of the generator 41 is low. When the electric power necessary for driving the motor 43 cannot be supplied, the amount of current passing through the bypass circuit 46 is increased. Thereby, the power supply to the battery 45 can be reduced, and the power used for driving the motor 43 can be increased. Actually, as shown in FIG. 6, the generated electromagnetism DUTY is supplied to the battery target voltage control unit 54, and the battery target voltage control unit 54 determines that the power generation capacity is insufficient based on the generated electromagnetism DUTY. When DUTY is large, control is performed so that the target voltage of the battery 45 is lowered.

<Description of the second embodiment>
FIG. 7 is a view for explaining a second embodiment of the vehicle power supply apparatus of the present invention. In the example shown in FIG. 7, 41 is a generator driven by an engine (not shown), 42 is an inverter, 43 is a motor, 44 is vehicle electrical equipment, 45 is a battery, and the vehicle electrical equipment 44 and the battery 45 are vehicles. It constitutes the entire electrical system. In the example shown in FIG. 7, the point that the electrical system (the vehicle electrical system 44 and the battery 45) is connected in series downstream of the motor 43, and the point that the current bypass circuit 46 is provided in parallel to the electrical system. This is the same as in the first embodiment. The second embodiment is different from the first embodiment described above in that a relay circuit 47 is provided in parallel with the motor 43.

  In the second embodiment of the present invention, when the relay circuit 47 is turned off, the circuit configuration is the same as that of the first embodiment shown in FIG. 4, and the same operation as that of the first embodiment shown in FIGS. . On the other hand, in the second embodiment, it is possible to configure the motor 34 and the electrical system to be connected in parallel by turning on the relay circuit 47.

  In the second embodiment of the present invention, when the required voltage of the motor 43 is low and the electrical system required voltage is sufficient, the relay circuit 47 is turned on, and both the motor 43 and the electrical system are connected in parallel. Supply power. At this time, as shown in an example of control in FIG. 8, the generator 41 is controlled by the generator field DUTY so that the battery voltage Vbat becomes the battery target voltage. Here, when the motor 43 is an AC motor, as shown in FIG. 8, the motor control unit 51 controls the inverter 42 with the bypass circuit 46 fully opened. On the other hand, when the motor 43 is a DC motor, the current is fed back and the output of the motor 43 is controlled using the bypass circuit 46.

  FIG. 9 is a flowchart showing the operation of the second embodiment of the vehicle power supply apparatus of the present invention described above. The second embodiment will be described with reference to the flowchart shown in FIG. 9. First, the magnitude of the required voltage of the motor is determined (step 1). When the required voltage of the motor is small, the relay circuit 47 is turned on and the control described in FIG. 8 is performed (steps 2 to 4). On the other hand, when the required voltage of the motor is large, the relay circuit 47 is turned off (step 5). Next, it is determined whether the power generation capacity is insufficient (step 6). If the power generation capacity is sufficient, the control described in FIG. 5 is performed (steps 7 to 9). On the other hand, when the power generation capacity is insufficient, the control described in FIG. 6 is performed (steps 10 to 12). As described above, the operation is performed while switching the three patterns.

  According to the vehicle power supply device of the present invention, an electrical system is connected in series downstream of the motor, a current bypass circuit is provided in parallel with the electrical system, and the current passing through the bypass circuit is controlled, thereby providing the electrical system. Since the configuration is such that the supplied voltage is adjusted, the amount of battery discharge during motor driving can be suppressed, and the life of the battery can be extended. Therefore, various generators such as generators used in four-wheel drive vehicles can be used. It can use suitably as an electric power supply device of vehicles of the composition of.

It is a figure for demonstrating an example of the four-wheel drive vehicle which can apply the generator control apparatus of this invention suitably. It is a circuit diagram for demonstrating an example of the field control in a generator. It is a figure for demonstrating the concept of an example of the electric power supply apparatus of the vehicle of this invention. It is a figure for demonstrating the 1st Example in the electric power supply apparatus of the vehicle of this invention. It is a figure for demonstrating an example of operation | movement of 1st Example shown in FIG. It is a figure for demonstrating the other example of operation | movement of 1st Example shown in FIG. It is a figure for demonstrating the 2nd Example in the electric power supply apparatus of the vehicle of this invention. It is a figure for demonstrating an example of operation | movement of 2nd Example shown in FIG. It is a flowchart which shows operation | movement of 2nd Example in the electric power supply apparatus of the vehicle of this invention. It is a figure for demonstrating the basic composition in the electric power supply apparatus of the conventional vehicle.

Explanation of symbols

1L, 1R Front wheel 2 Engine 3L, 3R Rear wheel 4 Motor 6 Belt 7 Generator 8 4WD controller 9 Inverter 11 Reducer 12 Clutch 27FL, 27FR, 27RL, 27RR Wheel speed sensor 31 Power supply 32, 33 Load 34 Variable resistance 41 Engine 42 Inverter 43 Motor 44 Vehicle electrical equipment 45 Battery 46 Bypass circuit 51 Motor control unit 52 Generator control unit 53 Bypass control unit 54 Battery target voltage control unit

Claims (5)

  In a vehicle power supply device that supplies power to an electrical system and a motor with a generator driven by an engine, the electrical system is connected in series downstream of the motor, and a current bypass circuit is provided in parallel with the electrical system to bypass A power supply apparatus for a vehicle, characterized in that a voltage supplied to an electrical system is adjusted by controlling a current passing through a circuit.   The vehicle power supply device according to claim 1, wherein when the power generation capacity of the generator is low and electric power necessary for driving the motor cannot be supplied, the amount of current passing through the bypass circuit is increased.   When a relay circuit is provided in parallel with the motor and the voltage required by the motor is low and the voltage required by the vehicle electrical equipment is sufficient, the motor and electrical equipment are connected in parallel by turning on the relay circuit. The vehicle power supply according to claim 1 or 2, characterized in that the voltage required by the vehicle electrical equipment is generated and the generated power is supplied to both the motor and the electrical system at the same time. apparatus.   4. The vehicle power supply device according to claim 3, wherein when the motor is an AC motor, the motor output is controlled by an inverter.   4. The power supply apparatus according to claim 3, wherein when the motor is a DC motor, the motor output is controlled by a current flowing through the bypass circuit.

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