JP5387035B2 - Power supply system for automobile and power supply control method thereof - Google Patents

Description

  The present invention relates to an automobile power supply system and a power supply control system therefor, and more particularly, in an automobile having a first power supply having a generator that generates electric power by the operation of an internal combustion engine and a second power supply that can be charged from the outside of the vehicle. The present invention relates to an automotive power supply system capable of improving the power utilization efficiency and a power supply control method thereof.

  In the automobile industry against the backdrop of heightened awareness of environmental issues and crude oil and energy problems, plugs that can reduce the environmental impact even more than electric vehicles (BEVs), hybrid electric vehicles (HEVs), or hybrid vehicles. The demand for in-hybrid vehicles is expected to increase.

  As illustrated in FIG. 8, in the electric vehicle, a secondary battery 52A that can be charged from an external power source 51 is mounted on a vehicle 50A, and an electric motor 53 is operated by electric power charged in the secondary battery 52A to drive wheels. 54 is driven. Further, as illustrated in FIG. 9, the hybrid vehicle uses an internal combustion engine 56 that operates by combustion of fuel in the fuel tank 55 of the vehicle 50 </ b> B and the electric motor 53 as a power source of the vehicle 50 </ b> B. It has a structure provided with a battery 57 for power transfer. Further, as illustrated in FIG. 10, the plug-in hybrid vehicle uses the internal combustion engine 56 and the electric motor 53 together as a power source of the vehicle and uses the electric power charged in the secondary battery 52 </ b> B that can be charged from the external power source 51. The drive wheel 54 is driven by operating the electric motor 53.

  By the way, it is conceivable to improve fuel efficiency by adopting a plug-in hybrid system for large commercial vehicles, but in that case, a large capacity is required for the secondary battery, and a large amount of secondary batteries are to be installed. Therefore, it cannot be realized with the current technology.

  Therefore, the present inventor further examined the use of a secondary battery in a large commercial vehicle, and it is difficult to mount a secondary battery having energy to move the large commercial vehicle. It was found that a secondary battery having a power capacity sufficient to operate the battery can be mounted.

  Here, in the electric vehicle, in addition to the main power storage device that supplies power to the traveling motor, an auxiliary power storage device that supplies power to the auxiliary equipment is provided, and power is supplied to the auxiliary equipment from there. A structure is disclosed in which the power of the main power storage device is supplied to an auxiliary machine when the charging power of the device is insufficient (see, for example, Patent Document 1).

  In this structure, since the power of the auxiliary power storage device is supplied to the auxiliary machinery, it is normally said that the power of the main power storage device is not consumed and the mileage of the vehicle can be extended. The auxiliary machine to which is supplied is exclusively a starter motor, and sufficient consideration is not given to the power utilization efficiency in various states such as running, deceleration, idling and stopping of the automobile.

JP 2001-275201 A

  SUMMARY OF THE INVENTION An object of the present invention is an automobile capable of improving power utilization efficiency in an automobile having a first power source having a generator that generates electricity by the operation of an internal combustion engine and a second power source that can be charged from the outside of the vehicle. Power supply system and power supply control method thereof.

Automotive power supply system of the present invention for achieving the above object, a has an internal combustion engine for driving the driving wheels of the vehicle, a battery that is charged by the generator and the generator to generate power by the operation of the internal combustion engine 1 In an automotive power supply system having a power source and an electrical accessory capable of supplying power from the first power source, charging from an external power source of the vehicle is possible, and power is supplied to the electrical accessory. A second power source capable of switching the main power supply source to the electrical accessory to one of the first power source and the second power source, and the first power source, the electrical accessory, and the Switching means provided in a state where a switch and a DC / DC converter are connected in series with the second power supply, and control means for controlling the switching means, the control means for stopping the vehicle time, outside the second power supply As charge is available from, it has a function of instructing the second power source to said switching means to electrically disconnect from the first power source and the electric accessory, or idling during running of the vehicle , By setting the output voltage of the DC / DC converter to be higher than the adjustment voltage of the first power supply, power is supplied from the second power supply to the electrical accessory, and from the second power supply While electric power is being supplied to the electrical accessory, the power generation operation of the generator is stopped.

  Further, in the above-described automobile power supply system, the control means electrically connects the first power supply and the electrical accessory when the vehicle decelerates, and supplies power from the first power supply to the electrical accessory. In this configuration, the switching means is instructed to supply.

In the above-described automobile power supply system, the control means may stop or reduce the output of the DC / DC converter while the switch is on with respect to the switching means during deceleration of the vehicle. It has a function to instruct.

Further, in the above-described automobile power supply system, the control means may supply the second power supply from the first power supply and the electrical accessory when the charge capacity of the second power supply is equal to or lower than a preset charge capacity. And having the function of instructing the switching means to electrically connect the first power source and the electrical accessory.

The power supply control method for an automotive power supply system of the present invention, the first power supply having an internal combustion engine for driving the driving wheels of the vehicle, a battery that is charged by the generator and the generator to generate power by the operation of the internal combustion engine And a power supply control method for an automotive power supply system that can supply power from the first power supply, and charging from an external power supply of the vehicle is possible, and the electrical accessory is A second power source capable of supplying power; and acquiring vehicle information; and determining that the vehicle is stopped based on the vehicle information, so that the second power source can be externally charged. a step of disconnecting electrically the second power supply the first power source and the electric accessory, on the basis of the vehicle information, it is determined that the vehicle traveling state or idling state, and the said second power supply electric accessory Vapor to connect, and the second step of supplying power from a power source to said electric accessory, on the basis of the vehicle information, when it is determined that the vehicle deceleration state, electrically and the electric auxiliary machine and the first power supply And supplying power to the electrical accessory from the first power source , and further determining that the vehicle is running and supplying power to the electrical accessory from the second power source. During this period, the power generation operation of the generator is stopped, the vehicle is determined to be in a deceleration state, and the power generation operation of the generator is performed while power is supplied from the first power source to the electrical accessory. is there.

In the power control method for an automotive power system described above, the charge capacity is equal to or less than a preset charge capacity based on the step of detecting the charge capacity of the second power supply and the information on the charge capacity of the second power supply. The second power supply is electrically disconnected from the first power supply and the electrical accessory, and the first power supply and the electrical accessory are electrically connected to the electrical accessory from the first power supply. Supplying power.

According to the present invention, when the vehicle is stopped, the second power source is electrically disconnected from the first power source and the electrical accessory so that the second power source can be charged from the outside. Alternatively, during idling, the second power source and the electrical accessory can be electrically connected to supply power from the second power source to the electrical accessory, thereby improving the power utilization efficiency.

It is explanatory drawing which shows an example of the power transmission path | route of the motor vehicle which is one embodiment of this invention. It is explanatory drawing of the power supply system for motor vehicles of FIG. It is explanatory drawing of the power supply system for motor vehicles at the time of a vehicle stop. It is explanatory drawing of the power supply system for motor vehicles in a vehicle travel period. It is explanatory drawing of the power supply system for motor vehicles in a vehicle deceleration period. It is explanatory drawing of the power supply system for motor vehicles in the charge capacity shortage period of a 2nd power supply. It is a graph which shows the charging capacity of the 2nd power supply in each state of a vehicle, the output power of a 2nd power supply, and the output power of a generator. It is explanatory drawing of an electric vehicle. It is explanatory drawing of a hybrid vehicle. It is a figure of a plug-in hybrid vehicle.

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

  The automobile (vehicle) of the present embodiment is a commercial vehicle such as a freight car or a special-purpose car (a flat body, a van, a dump truck, a mixer, a tank truck, a freezer car, a refrigerated car, or a welfare car). FIG. 1 shows an example of a power transmission path of the automobile 1. In the power transmission system, a rotational motion created by an engine (internal combustion engine) 2 that operates by burning a fuel such as gasoline inside is transmitted to a transmission 3a, a propeller shaft 3b, a differential gear 3c, a drive shaft 3d, and the like. It is a general thing which transmits to the drive wheel 4 through such a power transmission device.

FIG. 2 shows an example of an automobile power supply system 1S for the automobile 1 shown in FIG. This automotive power supply system 1S includes a first power supply 5, a second power supply 6, a plurality of electrical accessories 7, a switching circuit 8, and control circuits 9a and 9b.

  The first power supply 5 has a generator 5a and a battery (storage battery) 5b. The generator 5 a is connected to the crankshaft 2 a of the engine 2 through the belt 10, and generates power by the rotation operation of the engine 2. The output of the generator 5a is electrically connected to the battery 5b, and the battery 5b can be charged with the electric power generated by the generator 5a.

  The battery 5b is a secondary battery such as a lead storage battery. The battery 5b is electrically connected to the starter 11, and the electric power stored in the battery 5b can be used as starter driving power when starting the engine.

  Furthermore, the output of the first power source 5 (that is, the output of the generator 5a and the battery 5b) is electrically connected to the plurality of electrical accessories 7, and the power of the generator 5a and the battery 5b is It can be supplied to a desired electrical accessory 7. The electrical accessory 7 is, for example, an actuator such as a motor or an electromagnet that drives lighting, air conditioning, a wiper, a power window, a refrigerator / freezer, an electric shutter, an electric elevator, or various devices.

  The second power source 6 is a secondary battery such as a nickel metal hydride battery or a lithium ion battery. The second power source 6 is electrically connected to the plug receptacle PL via the control circuit 9b. The plug receptacle PL is provided so as to be exposed on the outer wall surface of the vehicle body of the automobile 1, and the power of the external power source can be charged to the second power source 6 by inserting the plug of the external power source into the plug receptacle PL. It has become. The control circuit 9b is a control circuit for charge control when the second power source 6 is charged with external power. This charging control may be performed by a control circuit 9a described later.

Further, the second power source 6 is electrically connected to the first power source 5 (outputs of the generator 5a and the battery 5b) and the plurality of electrical accessories 7 via the switching circuit 8, and the second power source 6 Can be supplied to a desired electrical accessory 7 . That is, in the present embodiment, it is possible to supply power to the desired electrical accessory 7 from both the first power supply 5 and the second power supply 6.

  The switching circuit (switching means) 8 is a circuit for switching a main power supply source to a desired electrical accessory 7 to one of the first power supply 5 and the second power supply 6, and the switch 8S and DC / It has a DC converter 8C. The output of the second power source 6 is electrically connected to the first power source 5 and the plurality of electrical accessories 7 through the DC / DC converter 8C and the switch 8S in this order. That is, the switching circuit 8 is provided in a state in which the switch 8S and the DC / DC converter 8C are connected in series between the first power source 5 and the plurality of electrical accessories 7 and the second power source 6.

Switch 8S is a second power source 6, or electrically connected to the first power supply 5 and the electric auxiliary machine 7 is an electronic component or electrically disconnected from the first power source 5 and the electric auxiliary machine 7. The DC / DC converter 8 </ b> C is an electronic component that converts (boosts) the DC voltage supplied from the second power supply 6 into a preset DC voltage and supplies it to a desired electrical accessory 7.

In the present embodiment, the output voltage of the DC / DC converter 8C is set to be higher than the adjustment voltage of the first power supply 5 (the generator 5a). As a result, while the power is being supplied from the second power source 6 to the desired electrical accessory 7, the power generation operation of the generator 5 a can be automatically stopped, and the first power source 5 to the electrical accessory 7. The power supply can be automatically stopped. Thus, by using the DC / DC converter 8C that is relatively easy to miniaturize as an electronic component of the switching circuit 8, the switching circuit 8 can be provided without greatly degrading the limited space of the automobile 1.

  The operation of the switching circuit 8 is controlled by a control circuit (control means) 9a.

  Vehicle information A1 is transmitted to the control circuit 9a from each device of the automobile 1 or a sensor provided in each device. Based on the vehicle information A1, the control circuit 9a can grasp the operation state (stop, travel, idling and deceleration) of the automobile 1 in real time, and control the operation of the switching circuit 8 according to each operation state. It is possible.

When the control circuit 9a determines that the vehicle is stopped based on the vehicle information A1, the second power source 6 is connected to the first power source 5 and the electrical accessory 7 so that the second power source 6 can be charged from the external power source. The switching circuit 8 is instructed to be electrically disconnected from the switch. Specifically, the switch 8S of the switching circuit 8 is turned off. In addition, the vehicle stop said here means the complete stop state in which rotation operation itself of the engine 2 has stopped.

  When the control circuit 9a determines that the vehicle is traveling or idling based on the vehicle information A1, the control circuit 9a electrically connects the second power source 6 and the electrical accessory 7 and the second power source 6 It has a function of instructing the switching circuit 8 to supply electric power to the electrical accessory 7. Specifically, both the switch 8S and the DC / DC converter 8C are turned on. Note that the power of the second power source 6 is set not to be charged in the battery 5b when the vehicle is running or idling.

  When the control circuit 9a determines that the vehicle is in a deceleration state based on the vehicle information A1 such as the accelerator opening, for example, the control circuit 9a electrically connects the first power supply 5 and the electrical accessory 7 to the first power supply. 5 has a function of instructing the switching circuit 8 to supply power to the desired electrical accessory 7. Specifically, the power output of the DC / DC converter 8C is stopped or reduced while the switch 8S is kept on. It is set so that the power of the generator 5a is not charged in the second power source 6 when the power output of the DC / DC converter 8C is reduced during vehicle deceleration.

Furthermore, the state of charge (SOC) information A2 of the second power supply 6 detected by a sensor provided in the second power supply 6 is transmitted to the control circuit 9a. When the charge capacity of the second power source 6 becomes equal to or less than a preset charge capacity value based on the charge state information A2, the control circuit 9a replaces the second power source 6 with the first power source 5 and the electrical supplement. A function of instructing the switching circuit 8 to electrically disconnect the first power supply 5 and the electrical accessory 7 from the machine 7 and to electrically supply the desired electrical accessory 7 from the first power supply 5 have. Specifically, the switch 8S of the switching circuit 8 is turned off.

Next, a control method of the automotive power supply system 1S of the present embodiment will be described with reference to FIGS.

3 to 6 show the state of the automobile power supply system 1 </ b> S in each operation state of the automobile 1 . Arrows P1 to P8 indicate the state of power supply. FIG. 7 shows the charging capacity of the second power source 6, the output power of the second power source 6 (DC / DC converter 8 </ b> C), and the output power of the generator 5 a in each operation state of the automobile 1. The abscissa represents time, the time t1 to t2 is the vehicle stop period S1, the time t2 to t3, t4 to t5, t6 to t7 is the vehicle travel period D1, D2, D3, and the time t3 to t4, t5 to t6 is The vehicle deceleration periods SD1 and SD2 and the time t7 and thereafter show the charging capacity shortage period ST of the second power source 6, respectively.

  First, the control circuit 9a acquires the vehicle information A1 and grasps the vehicle operating state.

When the control circuit 9a determines that the vehicle is stopped based on the vehicle information A1, as shown in FIG. 3, the switch 8S is turned off so that the second power source 6 can be charged from the outside so that the second power source 6 is turned on. The first power supply 5 and the electrical accessory 7 are electrically disconnected. Thus, the driver can insert the plug of the external power source into the plug receptacle PL and charge the power of the external power source to the second power source 6 as indicated by the arrow P1 (vehicle stop period S1 in FIG. 7). The vehicle information A1 indicating that the vehicle is stopped may be transmitted to the control circuit 9a when the starter 11 of the automobile 1 is switched off, or into the control circuit 9a when an external power plug is inserted into the plug receptacle PL. It may be transmitted.

  Next, when the control circuit 9a determines that the vehicle is running or idling based on the vehicle information A1, the control circuit 9a turns on the switch 8S and the DC / DC converter 8C as shown in FIG. The electrical accessory 7 is electrically connected. At this time, the output voltage of the DC / DC converter 8C is made higher than the adjustment voltage of the first power supply 5 (generator 5a). Thereby, while supplying the electric power of the 2nd power supply 6 to the desired electrical equipment auxiliary machine 7 as shown by arrow P2, the electric power generation operation | movement of the generator 5a can be stopped automatically, and the desired power supply from the 1st power supply 5 is possible. It is possible to automatically stop the power supply to the electrical accessory 7 (vehicle travel periods D1 to D3 in FIG. 7).

Thus, in the present embodiment, since the power generation operation of the generator 5a can be stopped while the vehicle is traveling and idling, the load on the engine 2 can be reduced and the fuel consumption performance can be improved. In addition, since electric power is supplied from the second power source 6 to the desired electrical accessory 7 while the vehicle is running and idling, it is possible to eliminate the need to carry out electric power from the battery 5b, and to reduce the load on the battery 5b. Thereby, the lifetime of the battery 5b can be improved.

Next, when the control circuit 9a determines that the vehicle is decelerating based on the vehicle information A1 such as the accelerator opening, for example, as shown in FIG. 5, the switch 8S is kept on and the DC / DC converter 8C is turned on. Stop or reduce power output. Thereby, the generator 5a performs a power generation operation. That is, the first power supply 5 and the desired electrical accessory 7 are electrically connected, and the power of the first power supply 5 is supplied to the desired electrical accessory 7 as indicated by arrows P3 and P4 (FIG. 7). Vehicle deceleration period SD1, SD2 ).

The power supply from the first power source 5 to the desired electrical accessory 7 is mainly supplied by the power from the generator 5a (arrow P3), but when shortage occurs, the power from the battery 5b (arrow P4) To compensate. At this time, the electric power generated by the generator 5a is also charged in the battery 5b as shown by an arrow P5. When the power output of the DC / DC converter 8C is reduced, the power of the second power source 6 is also supplied to the desired electrical accessory 7 slightly.

As described above, in the present embodiment, the electric power generated by the generator 5a by the braking energy during vehicle deceleration can be supplied to a desired electrical accessory 7 . That is, since braking energy can be regenerated, energy use efficiency can be improved. In addition, since the power supply of the second power source 6 can be stopped (or reduced) while the vehicle is decelerating, the decrease in the charging capacity of the second power source 6 can be delayed, and the second power source 6 can be used in one charge. The time that can be done can be lengthened.

Next, the control circuit 9a sets the charging capacity of the second power supply 6 that is set in advance based on the charging state information A2 of the second power supply 6 detected by the sensor provided in the second power supply 6. When it is determined that the following has occurred, the switch 8S is turned off as shown in FIG. 6, and the second power source 6 is electrically disconnected from the first power source 5 and the electrical accessory 7 . In this case , the power supply to the electrical accessory 7 is the same as that of a general automobile without the second power source 6. That is, the first power supply 5 and the desired electrical accessory 7 are electrically connected, and the power of the first power supply 5 is supplied to the desired electrical accessory 7 as indicated by arrows P6 and P7 (FIG. 7). Charging capacity shortage period ST ). By monitoring in this way the charge capacity of the second power supply 6, can be automatically detecting the charge capacity shortage of the second power supply 6, when it is determined that the charge capacity shortage of the second power source 6, electric accessory The power supply to the machine 7 can be automatically switched from the second power supply 6 to the first power supply 5. The power supply from the first power supply 5 to the desired electrical accessory 7 is mainly supplied from the generator 5a (arrow P6), but the shortage is also supplied from the battery 5b (arrow P7). At this time, the electric power generated by the generator 5a is also charged to the battery 5b (arrow P8).

Thus, according to the present embodiment, in the automobile 1 having the first power source 5 having the generator 5a that generates power by the operation of the engine 2 and the second power source 6 that can be charged from the external power source, various operation states are brought about. Accordingly , by appropriately switching the power supply source for the electrical accessory 7 between the first power supply 5 and the second power supply 6 , the power use efficiency can be improved.

In addition, since power is supplied from the second power source 6 to the electrical accessory 7 , charging power is necessary, but power is more economically advantageous in terms of energy cost, and carbon dioxide (CO 2). Emissions can be reduced. By using a high-performance secondary battery such as a lithium ion battery as the secondary battery of the second power source 6, even a small battery that can be mounted on the vehicle can supply about half a day of power . Charging when the vehicle stops, such as unloading or resting, makes it possible to supply power for one day. Furthermore, the automobile power supply system 1S according to the present embodiment does not require significant modification of the vehicle, and can be retrofitted to the current standard vehicle.

DESCRIPTION OF SYMBOLS 1 Automobile 1S Automobile power supply system 2 Engine 2a Crankshaft 3a Transmission 3b Propeller shaft 3c Differential gear 3d Drive shaft 4 Drive wheel 5 First power supply 5a Generator 5b Battery (storage battery)
6 Second power source 7 Electrical accessory 8 Switching circuit (switching means)
8S switch 8C DC / DC converter 9a control circuit (control means)
9b Control circuit 10 Belt 11 Starter PL Plug receptacle

Claims (6)

An internal combustion engine that drives the drive wheels of the vehicle;
In an automotive power supply system having a first power source having a generator that generates electric power by the operation of the internal combustion engine and a storage battery charged by the generator, and an electrical accessory that can supply power from the first power source ,
A second power source capable of being charged from a power source external to the vehicle and capable of supplying power to the electrical accessory;
In order to switch a main power supply source to the electrical accessory to one of the first power source and the second power source, between the first power source and the electrical accessory and the second power source, Switching means provided in a state where the switch and the DC / DC converter are connected in series, and control means for controlling the switching means,
The control means includes
A function of instructing the switching means to electrically disconnect the second power source from the first power source and the electrical accessory so that the second power source can be charged from the outside when the vehicle is stopped. Have
While the vehicle is running or idling , power is supplied from the second power source to the electrical accessory by setting the output voltage of the DC / DC converter to be higher than the adjustment voltage of the first power source. And a power supply system for a vehicle configured to stop the power generation operation of the power generator while power is being supplied from the second power source to the electrical accessory . The control means instructs the switching means to electrically connect the first power source and the electrical accessory when the vehicle decelerates and to supply power from the first power source to the electrical accessory. The automobile power supply system according to claim 1 having a function . The control unit has a function of instructing the switching unit to stop or reduce the output of the DC / DC converter while the switch is turned on when the vehicle is decelerated. the power supply system for the automobile. The control means electrically disconnects the second power source from the first power source and the electrical accessory when the charging capacity of the second power source is equal to or lower than a preset charging capacity, and The automobile power supply system according to any one of claims 1 to 3, which has a function of instructing the switching means to electrically connect an electrical accessory . An internal combustion engine for driving a drive wheel of a vehicle, a first power source having a generator for generating electric power by the operation of the internal combustion engine, and a storage battery charged by the generator, and an electrical component capable of supplying power from the first power source A power control method for an automotive power system having a machine,
A second power source capable of charging from an external power source of the vehicle and capable of supplying power to the electrical accessory;
Obtaining vehicle information;
Electrically disconnecting the second power source from the first power source and the electrical accessory so that the second power source can be externally charged when it is determined that the vehicle is stopped based on the vehicle information;
When it is determined that the vehicle is running or idling based on the vehicle information, electrically connecting the second power source and the electrical accessory and supplying power from the second power source to the electrical accessory; ,
When determining that the vehicle is in a deceleration state based on the vehicle information, the method includes electrically connecting the first power source and the electrical accessory and supplying power from the first power source to the electrical accessory. ,
Further, the power generation operation of the generator is stopped while the vehicle running state is determined and power is being supplied from the second power source to the electrical accessory.
A power supply control method for an automotive power supply system that performs a power generation operation of the generator while it is determined to be in the vehicle deceleration state and power is supplied from the first power supply to the electrical accessory . Detecting a charge capacity of the second power source;
Based on the information on the charging capacity of the second power source, when the charging capacity is equal to or lower than a preset charging capacity, the second power source is electrically disconnected from the first power source and the electrical accessory, 6. The power supply control method for an automotive power supply system according to claim 5, further comprising a step of electrically connecting one power source and the electric accessory to supply electric power from the first power source to the electric accessory .

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