JP2011131827A - Electric power supply unit for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric power supply unit for a hybrid vehicle, which is capable of improving fuel consumption by suppressing operation of a generator by an internal combustion engine and capable of suppressing biased reduction of service life caused only by a specific power supply among a plurality of power supplies connected in series. <P>SOLUTION: The electric power supply unit for the hybrid vehicle includes: a first battery (2) for supplying electric power to a first electric load (7) via a first circuit (6); a second battery (3) for supplying electric power to a second electric load (12) via a second circuit (5) as well as the first battery; the generator (13) driven by the internal combustion engine by being connected by the second circuit; a first electric voltage regulator (14) for regulating an input voltage to the first and the second batteries from the second circuit; a third battery (8) having a high electric voltage for driving a travel motor; and a second electric voltage regulator (10) for supplying electric power of an electric voltage of the first battery to the first electric load and an electric voltage that is higher than a regulated voltage of the first regulator by stepping down the input voltage from the third battery. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power supply apparatus for a hybrid vehicle, and more particularly, to a technique for supplying power from a traveling battery to electric loads having different voltages.

  Large vehicles equipped with an internal combustion engine include those for controlling internal combustion engines designed with a power supply voltage of 12V for the purpose of reducing costs and improving reliability by sharing parts with small and medium-sized vehicles and passenger cars. Are used, and a starter for starting an internal combustion engine. In addition, a device such as a refrigerator that is designed with a power supply voltage of 24 V as in the past is used for vehicle mounting or the like.

For this reason, as a power source for large vehicles, a mode in which a 24V main power circuit is provided and a DC 12V power source is obtained using a DC-DC conversion circuit has become widespread.
However, in the above circuit configuration, if the conversion from the rated voltage 24V of the main power supply to 12V for each control device is interrupted due to a failure of the DC-DC conversion circuit, a situation may occur in which the vehicle stops on the running road.

  Therefore, even if a failure occurs in the DC-DC conversion circuit, a plurality of 12V power supplies are connected in series so that the running vehicle can travel to the vehicle base and service factory by itself without stopping on the road, By supplying power to each control device etc. from one 12V power supply, power can be supplied to the 24V main power supply circuit and the 12V power supply circuit, and the vehicle can run even when the DC-DC conversion circuit fails. A vehicle power supply device has been developed (Patent Document 1).

JP 2007-118656 A

In the vehicle power supply device of Patent Document 1, a plurality of 12V power supplies are connected in series so that power can be supplied when the DC-DC conversion circuit fails, so that the vehicle can run.
However, since power is supplied to each control device from a specific 12V power supply among a plurality of 12V power supplies connected in series, and only the power of the specific 12V power supply is consumed, the specific 12V power supply is consumed. This is not preferable because only the power source has a reduced life, and the life balance is lost among a plurality of power sources.

  Therefore, a 24V generator is operated by an internal combustion engine to generate 24V power, and power is supplied to each control device from a specific 12V power supply among 12V power supplies connected in series. In order to prevent the consumption of only the 12V power supply, it may be possible to replenish the power to the plurality of 12V power supplies evenly through, for example, a voltage regulator. It is possible to suppress a decrease in life.

  Furthermore, recently, various types of hybrid vehicles have been developed that include, for example, a traveling motor together with an internal combustion engine, and have a high-voltage (for example, 270 V) DC power supply to supply power to the traveling motor. In a hybrid vehicle, high-voltage power is converted into DC 12V by a DC-DC conversion circuit having higher power generation efficiency than a generator that supplies 12V using an internal combustion engine, and the converted 12V power is controlled by each control. It is considered to eliminate the deterioration of fuel consumption by using it for devices.

However, even when such high-voltage power is used as a 12V power source, if the 12V or 24V generator is operated in the internal combustion engine at the same time, the fuel consumption will still deteriorate. It cannot be solved and is not preferable.
Further, when only a specific 12V power source is used as described above, a phenomenon may occur in which only the specific 12V power source is replenished with a 12V power from a high voltage power source. Since no regulator is used, there is still a problem that only the life of a specific 12V power supply is reduced, and the life balance among a plurality of power supplies is greatly lost.

  The present invention has been made to solve such problems. The object of the present invention is to improve fuel efficiency by suppressing the operation of a 12V or 24V generator by an internal combustion engine. Another object of the present invention is to provide a power supply device for a hybrid vehicle capable of suppressing an uneven life reduction of only a specific power supply among a plurality of power supplies connected in series.

  In order to achieve the above object, a power supply apparatus for a hybrid vehicle according to claim 1 is a power supply apparatus for a hybrid vehicle having an internal combustion engine and a traveling motor, and the first electric load via the first circuit. A first battery capable of supplying power to the first battery, a second battery connected in series with the first battery, and capable of supplying power to the second electric load via the second circuit together with the first battery; A generator connected to a second circuit and driven by the internal combustion engine, connected to the first circuit and the second circuit, and a voltage input from the second circuit is applied to the first battery. A first voltage regulator that performs voltage regulation to supply power to the first circuit by converting the voltage of the second battery and the voltage of the second battery to a predetermined ratio that balances, and the voltage of the first battery and the voltage of the first battery The voltage adjusted by the first voltage regulator A third battery having a high voltage and a voltage inputted from the third battery via the third circuit, and supplying power to the first electric load via the first circuit. A voltage of power supplied to the first electric load of the second voltage regulator is adjusted by the voltage of the first battery and the first voltage regulator. The predetermined voltage is set to be higher than a predetermined voltage and lower than an allowable voltage of the first electric load.

According to a second aspect of the present invention, there is provided a power supply apparatus for a hybrid vehicle according to the first aspect, wherein the third battery is a traveling battery capable of storing a voltage for driving the traveling motor.
According to a third aspect of the present invention, there is provided a hybrid vehicle power supply apparatus according to the first or second aspect, wherein the first circuit includes power supply suppression means for suppressing power supply from the third voltage regulator to the first battery. It is characterized by that.

According to a fourth aspect of the present invention, there is provided the power supply apparatus for a hybrid vehicle according to any one of the first to third aspects, wherein the second voltage regulator is configured such that when the voltage of the third battery is equal to or lower than a predetermined ratio, The electric load is not supplied with power.
According to a fifth aspect of the present invention, there is provided a hybrid vehicle power supply apparatus according to any one of the first to third aspects, further comprising battery charge amount detection means for detecting a charge amount stored in the third battery,
The second voltage regulator does not supply power to the first electric load when the charge amount of the third battery detected by the battery charge amount detection means is equal to or less than a predetermined amount. To do.

  According to the first aspect of the present invention, from the third battery having a voltage higher than the voltage of the first battery and the voltage adjusted by the first voltage regulator, and the third battery via the third circuit. A second voltage regulator for stepping down an input voltage and supplying power to the first electric load via the first circuit, and supplying the second voltage regulator to the first electric load of the second voltage regulator The voltage of the electric power is set to be a predetermined voltage that is higher than the voltage of the first battery and the adjustment voltage of the first voltage regulator and lower than the allowable voltage of the first electric load.

As a result, the voltage of the third battery is converted and supplied to a predetermined voltage that can be supplied to the first electric load by the second voltage regulator, thereby suppressing the operation of the generator driven by the internal combustion engine. This can improve fuel efficiency.
Further, in the case of hybridizing an existing vehicle, the operation of the generator can be suppressed while suppressing an increase in cost without changing the arrangement configuration of auxiliary parts of the internal combustion engine.

According to invention of Claim 2, the 3rd battery is comprised with the battery for driving | running | working which can accumulate | store the voltage for driving a motor for driving | running | working.
Therefore, since the traveling battery normally used in the hybrid vehicle is used as the third battery, it is not necessary to install a new battery, and an increase in cost can be suppressed.
According to the invention of claim 3, the first circuit is provided with the power supply suppressing means to suppress the power supply from the second voltage regulator to the first battery.
Thereby, since the power supply from the second voltage regulator to the first battery is suppressed, the first battery can be charged from the first voltage regulator.

Accordingly, since the first battery can be charged from the first voltage regulator, the voltage balance between the first battery and the second battery is balanced, and the lifetime reduction of only the first battery is suppressed. Can do.
According to the fourth aspect of the present invention, the second voltage regulator prevents power from being supplied to the first electric load when the voltage of the third battery is equal to or lower than a predetermined ratio.

Accordingly, when the voltage of the third battery is equal to or lower than the predetermined ratio, power is not supplied from the third battery to the first electric load. Therefore, in a vehicle that considers the driving performance on the assumption that the driving motor is used. In addition to eliminating the influence on the running, the existing auxiliary machine parts can also eliminate the influence on the 12V supply.
According to the invention of claim 5, the battery charge amount detecting means for detecting the charge amount stored in the third battery is provided, and the second voltage regulator has a predetermined amount of charge of the third battery. When it is below, power is not supplied to the first electric load.
Therefore, when the charge amount of the third battery is equal to or less than the predetermined amount, no power is supplied from the third battery to the first electric load. Therefore, the vehicle considering the travel performance on the assumption that the travel motor is used. In addition, it is possible not only to eliminate the influence on the running, but also to eliminate the influence on the 12V supply by the existing auxiliary machine parts.

It is a schematic block diagram of the power supply device of the hybrid vehicle which concerns on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a power supply device for a hybrid vehicle according to an embodiment of the present invention. Hereinafter, the configuration of the power supply device of the hybrid vehicle will be described.

  As shown in FIG. 1, a hybrid vehicle power supply circuit 1 is connected in series with a first battery (first battery) 2 and a second battery (second battery) 3 that can each store a voltage of 12V. Is provided. That is, the first battery 2 and the second battery 3 are connected by the connection line 4. The output terminal of the second battery 3 is connected to the 24V system circuit 5 (second circuit). The connection line 4 branches off in the middle and is connected to the 12V system circuit 6 (first circuit).

The 12V system circuit 6 is connected to an electric load (hereinafter referred to as 12V load) 7 (first electric load) 7 having a rated voltage of 12V, such as a starter for starting an engine (internal combustion engine) (not shown) or an engine control device. Yes.
The 12V system circuit 6 includes a travel battery (third battery) 8 capable of storing a high voltage (for example, 270V) for driving a travel motor (not shown), and a high voltage circuit (third circuit). 9, connected via a DC-DC converter (second voltage regulator) 10.

  The DC-DC converter 10 has a high voltage of the traveling battery 8 that is higher than the adjustment voltage of the first battery 2 and an equalizer (first voltage regulator) 14 described later, and lower than the allowable voltage of the 12V load 7. It has a function of stepping down to (for example, 14 V) and supplying power to the 12 V load 7.

A battery charge amount detection sensor (battery charge amount detection means) 15 for detecting the charge amount of the travel battery 8 is connected between the travel battery 8 and the DC-DC converter 10.
Furthermore, the 12V system circuit 6 is provided with a diode (power supply suppressing means) 11 that prevents the first battery 2 from being supplied with power of a predetermined voltage supplied from the DC-DC converter 10.
On the other hand, a 24 V electric load (hereinafter referred to as a 24 V load) (second electric load) 12 such as a bodywork device (refrigerator) is connected to the 24 V system circuit 5.

A generator 13 is connected to the 24V system circuit 5. The generator 13 has a function of generating electric power of 24 V or more by being driven by the engine and supplying electric power to the 24 V system circuit 5.
Further, an equalizer 14 is connected between the 12V system circuit 6 and the 24V system circuit 5.

  In the equalizer 14, a 24V system circuit 5 is connected to an input terminal, and a 12V system circuit 6 is connected to an output terminal. The equalizer 14 monitors the voltage of the 24V system circuit 5 and the voltage of the 12V system circuit 6, and the voltage difference between the voltage of the 24V system circuit 5 and the voltage of the 12V system circuit 6 is equal to or greater than a predetermined voltage difference. Sometimes, in order to balance the voltages of the first battery 2 and the second battery 3, the voltage supplied from the 24V system circuit 5 is stepped down at a rate of 1/2 and supplied to the 12 system circuit 6. ing.

Hereinafter, the operation and effect of the power supply device for a hybrid vehicle according to the embodiment of the present invention configured as described above will be described.
In the hybrid vehicle power circuit 1 having the above configuration, power is normally supplied from the generator 13 or the first battery 2 and the second battery 3 connected in series to the 24V load 12.

  In addition, the voltage of the traveling battery 8 is equal to or less than a predetermined ratio (for example, 30%) of a rated voltage (for example, 270 V), or the charging amount of the traveling battery 8 detected by the battery charge amount detection sensor 15 is a predetermined amount (for example, When the DC-DC converter 10 determines that the charging rate is 30% or less, power is supplied from the first battery 2 to the 12V load 7. Thereby, the influence on driving | running | working of a vehicle can be eliminated.

  Otherwise, that is, when the voltage of the traveling battery 8 is larger than a predetermined ratio of the rated voltage, or when the charging amount of the traveling battery 8 detected by the battery charge amount detection sensor 15 is larger than the predetermined amount, DC-DC The converter 10 lowers the high voltage (for example, 270 V) supplied from the traveling battery 8 to a predetermined voltage (for example, 14 V) that is higher than the adjustment voltage of the equalizer 14 and lower than the allowable voltage of the 12 V load 7. Then, power is supplied to the 12V load 7. The first battery 2 is not supplied with power from the DC-DC converter 10 by the diode 11 provided in the 12V system circuit 6.

  Therefore, when the voltage of the traveling battery 8 is larger than a predetermined ratio of the rated voltage, or when the charging amount of the traveling battery 8 is larger than the predetermined amount, the power of the DC-DC converter 10 higher than the voltage of the first battery. Is supplied to the 12V load 7, only the power consumption of the first battery 2 does not increase, and the first battery 2 and the second battery 3 have the same power consumption. On the other hand, when the voltage of the traveling battery 8 is equal to or less than a predetermined ratio of the rated voltage, the first battery 2 supplies power to both the 24V load 12 and the 12V load 7. Consumption increases.

  At this time, the equalizer 14 monitors the voltages of the 24V system circuit 5 connected to the input terminal and the 12V system circuit 6 connected to the output terminal, and the voltage of the first battery 2 and the voltage of the second battery 3 are monitored. In order to balance the voltages, the voltage input from the 24V system circuit 5 is stepped down to a half voltage, and voltage adjustment for supplying power to the 12V system circuit 6 is performed.

  Specifically, the equalizer 14 is used when the difference between the half voltage input from the 24V system circuit 5 and the voltage of the 12V system circuit 6 is equal to or greater than a predetermined difference, that is, the voltage of the first battery 2 and The voltage adjustment is performed when the voltage of the second battery 3 is unbalanced. That is, by adjusting the voltage by the equalizer 14, the voltage of the first battery 2 and the voltage of the second battery 3 are maintained, while the voltage from the 24V system circuit 5 to the 12V load 7 of the 12V system circuit 6 or the first battery 2. Electric power is supplied to supplement the power consumption of the first battery 2.

  As described above, in the power supply device for a hybrid vehicle according to the embodiment of the present invention, power is preferentially supplied from the DC-DC converter 10 to the 12V load 7, so that the power consumption of the first battery 2 can be reduced. In addition, since the power supply from the DC-DC converter 10 to the first battery 2 is suppressed by the diode 11, the voltage of the first battery 2 can be adjusted by the equalizer 14.

Thereby, according to the power supply device of the hybrid vehicle which concerns on embodiment of this invention,
(1) Since the power consumption of the first battery 2 is reduced and the operation of the generator due to the voltage adjustment of the first battery 2 can be reduced, fuel consumption can be improved.
(2) Since the diode 11 suppresses power supply from the DC-DC converter 10 to the first battery 2 and the equalizer 14 adjusts the voltage between the first battery 2 and the second battery 3, The voltage balance with the second battery 3 can be achieved, and the lifetime reduction of only the first battery 2 can be suppressed.

(3) By adding a DC-DC converter 10 and a diode 11 to a power supply device in which a plurality of 12V power supplies of an existing vehicle are connected in series, driving without increasing the cost significantly without changing the configuration of the existing vehicle It can be set as the power supply device using the battery 8 for a vehicle.
Although the description of the embodiment of the invention is finished as above, the embodiment of the present invention is not limited to the embodiment.

  For example, although the present embodiment uses the diode 11 to suppress the power supply from the DC-DC converter 10 to the first battery 2, the present invention is not limited to this, and the first to the first batteries 2 are not limited to the first battery 2. Any device capable of suppressing the power supply to the battery 2 may be used.

2 First battery (first battery)
3 Second battery (second battery)
5 24V circuit (second circuit)
6 12V circuit (first circuit)
7 12V system load (first electric load)
8 Battery for travel (third battery)
9 High voltage circuit (third circuit)
10 DC-DC converter (second voltage regulator)
11 Diode (Power supply suppression means)
12 24V system load (second electrical load)
13 Generator 14 Equalizer (first voltage regulator)
15 battery charge detection sensor (battery charge detection means)

Claims (5)

A power supply device for a hybrid vehicle having an internal combustion engine and a traveling motor,
A first battery capable of supplying power to the first electrical load via the first circuit;
A second battery connected in series with the first battery and capable of supplying power to the second electrical load via the second circuit together with the first battery;
A generator connected to a second circuit and driven by the internal combustion engine;
Connected to the first circuit and the second circuit, and converts the voltage input from the second circuit into a predetermined ratio that balances the voltage of the first battery and the voltage of the second battery. A first voltage regulator that performs voltage regulation to supply power to the first circuit;
A third battery having a voltage higher than the voltage of the first battery and the voltage adjusted by the first voltage regulator;
A second voltage regulator that steps down a voltage input from the third battery via a third circuit and supplies power to the first electric load via the first circuit;
The voltage of the electric power supplied to the first electric load of the second voltage regulator is higher than the voltage of the first battery and the voltage adjusted by the first voltage regulator, and the first electric regulator A power supply apparatus for a hybrid vehicle, which is set to have a predetermined voltage lower than an allowable voltage of a load.   2. The hybrid vehicle power supply device according to claim 1, wherein the third battery is a traveling battery capable of storing a voltage for driving the traveling motor. 3.   3. The power supply apparatus for a hybrid vehicle according to claim 1, wherein the first circuit includes a power supply suppressing unit that suppresses power supply from the second voltage regulator to the first battery. 4.   The said 2nd voltage regulator does not supply electric power to a said 1st electric load, when the voltage of the said 3rd battery is below a predetermined ratio, The said 1st electric load is any one of the Claims 1 thru | or 3 characterized by the above-mentioned. The power supply apparatus of the described hybrid vehicle. Battery charge amount detecting means for detecting a charge amount stored in the third battery;
The second voltage regulator does not supply power to the first electric load when the charge amount of the third battery detected by the battery charge amount detection means is equal to or less than a predetermined amount. The power supply device for a hybrid vehicle according to any one of claims 1 to 3.

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