JP2016124481A - Vehicle power control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle power control device capable of maintaining the charge state of a power source in an appropriate state.SOLUTION: A vehicle power control device 6 used in a vehicle 1 having an engine 2, a generator 3, a battery 4, and an electric load 5 receiving power from the battery 4 to be driven mounted thereon includes a battery capacity calculation part 7 for detecting the SOC of the battery 4, a power consumption calculation part 8 for calculating the power consumption amount of the electric load 5, and a control unit 9 for issuing a command to the generator 3 to charge the battery 4 when the SOC detected by the battery capacity calculation part 7 is lower than predetermined reference SOC. The control unit 9 sets the reference SOC according to the power consumption amount calculated by the power consumption amount calculation part 8.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle power supply control device that controls the amount of charge to a power supply that is mounted on a vehicle and is charged by a generator that is driven by a driving force of an internal combustion engine to generate power.

  In a vehicle equipped with an internal combustion engine, a generator driven by the driving force of the internal combustion engine to generate electric power, a power source charged by the generator, and an electric load driven by power supplied from the power source, In order to keep the state of charge in an appropriate state, the generator is driven as necessary to generate power.

  For example, in Patent Document 1, the power generation range of the generator is set from the fuel increase amount corresponding to the increase in the driving force of the internal combustion engine necessary for charging, and the power generation range of the generator is changed based on the remaining capacity of the power source. A vehicle power supply control device has been proposed. According to the vehicle power supply control device described in the cited document 1, by generating power when the operating range of the internal combustion engine is included in the power generation range, an increase in fuel necessary for power generation, that is, consumption for power generation is performed. The amount of fuel used is reduced.

  Further, in order to accurately manage the voltage state of the power supply, in Patent Document 2, the fuel consumed by the internal combustion engine for power generation by the generator is determined as the power generation cost, and the command value of the power generation voltage is determined based on this power generation cost. There has been proposed a vehicle power supply control apparatus for setting According to the vehicle power supply control device described in the cited document 2, the voltage for issuing the power generation command does not change suddenly, and the power generation command to the generator is performed based on the power generation cost, so that the fuel consumption can be improved. .

JP 2005-12971 A JP 2008-228403 A

However, in the above cited references 1 and 2, the state of charge of the power supply is appropriately set by changing the power generation range based on the remaining capacity of the battery or setting the command value of the power generation voltage based on the fuel consumed by the internal combustion engine. However, since the amount of power consumed by the electric load mounted on the vehicle is not taken into consideration, the amount of charge of the power source is reduced when the amount of power consumed by the electric load of the vehicle is large. If the power generation amount for charging the lowered power source is reduced, there is a possibility that the appropriate charging state of the power source cannot be maintained.

  Then, an object of this invention is to provide the vehicle power supply control apparatus which can maintain the charge condition of a power supply in an appropriate state.

  In order to solve the above problems, the present invention provides an internal combustion engine, a generator that is driven by the driving force of the internal combustion engine to generate power, a power source that is supplied with power from the generator and charged, and power is supplied from the power source. A power capacity calculation unit for detecting a remaining capacity of the power of the power source and a power consumption calculation unit for calculating the power consumption of the electric load And a control unit for instructing the generator to generate power so that the power source is charged when the remaining capacity detected by the power source capacity calculation unit falls below a predetermined capacity reference value. The control unit calculates power consumption. The capacity reference value is set according to the power consumption calculated by the unit.

  Thus, according to the present invention, the state of charge of the power source can be maintained in an appropriate state even when the amount of power consumed by the electric load of the vehicle is large.

FIG. 1 is an overall configuration diagram showing a vehicle power supply control device according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration of the control unit. FIG. 3 is a diagram showing the relationship between the electric load of the vehicle and the charging rate of the battery. FIG. 4 is a diagram showing the relationship between engine torque and power generation cost. FIG. 5 is a flowchart showing a flow of processing for controlling charging of the battery, which is executed by the vehicle power supply control device according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, a vehicle 1 using a vehicle power supply control device 6 according to an embodiment of the present invention includes an engine 2 as an internal combustion engine, and power generation that is driven by the driving force of the engine 2 to generate electric power. A machine 3, a battery 4 as a power source that is charged by being supplied with electric power from the generator 3, and an electric load 5 that is driven by being supplied with electric power from the battery 4 are mounted.

  An engine 2 mounted on the vehicle 1 is connected to a generator 3 via a belt (not shown) or the like, and transmits rotational driving force to the generator 3 via the belt or the like to drive the generator 3 to generate power. .

  The generator 3 is a so-called motor generator (M / G), and supplies the battery 4 and the electric load 5 with electric power generated by driving with the driving force of the engine 2. Further, when the vehicle 1 is decelerated, the generator 3 can perform regenerative power generation by converting the kinetic energy of the vehicle 1 into electric energy and causing the power generator 3 to generate power, and the power generated by the regenerative power generation is charged in the battery 4. Is done.

  The battery 4 includes two batteries, a main battery 4a and a sub battery 4b. The main battery 4a is a lead storage battery, has a charge acceptance characteristic that is inferior to that of the sub battery 4b, and has a characteristic that it takes time to charge when the electric power generated by the generator 3 is charged.

  The sub-battery 4b is, for example, a lithium battery, has good charge acceptance characteristics, and can be charged in a short time when charging power generated by the generator 3 or power generated by regenerative power generation of the generator 3. Has characteristics that can be.

  The electric load 5 includes an electric load 5a that is mainly supplied with electric power from the main battery 4a and an electric load 5b that is mainly supplied with electric power from the sub-battery 4b, both of which are electric components mounted on the vehicle 1. The batteries (main battery 4a and sub-battery 4b) 4 that supply electric power to these electric loads 5a and 5b are controlled in charge / discharge state by the vehicle power supply control device 6. The vehicle power supply control device 6 includes a battery capacity calculation unit 7, a power consumption calculation unit 8, a control unit 9, and a power generation cost calculation unit 10.

  The battery capacity calculation unit 7 of the vehicle power supply control device 6 is connected to the main battery 4a and the sub battery 4b, and calculates the remaining capacity (hereinafter referred to as “SOC”) of the main battery 4a and the sub battery 4b. In the present embodiment, the SOC of main battery 4a is described as “SOC1”, and the SOC of sub battery 4b is described as “SOC2”. In order to calculate SOC1 and SOC2 of the main battery 4a and the sub-battery 4b, calculation is performed using either or both of an integrated value of charge / discharge currents of the batteries 4a and 4b, a value calculated based on voltage characteristics, or both.

The power consumption calculation unit 8 calculates the vehicle electrical load by adding up the power consumption amounts of components (electrical components) that are installed and operating in the vehicle. The power consumption in each component (electrical component) is measured in advance and stored in a storage unit (not shown).
The vehicle electrical load is calculated for each battery (main battery 4a, sub-battery 4b) 4 that supplies power.

  The power generation cost calculation unit 10 receives the detection result of the rotational speed of the engine 2, the detection result of the engine torque, and the detection result of the fuel consumption rate, and from these detection results, the fuel consumption per unit generated power (hereinafter “ Power generation cost). The calculation result is sent to the control unit 9, and the control unit 9 determines whether or not to charge the battery 4 based on the calculation result.

  The control unit 9 includes a capacity reference value setting unit 11 that sets a reference SOC that is a predetermined capacity reference value of the main battery 4a and the sub battery 4b, and a power generation cost reference value setting unit 12 that sets a predetermined power generation cost reference value. And a power generation command unit 13 that outputs a power generation command to the generator 3. The reference SOC is a reference for charging the battery 4. For example, when the SOC falls below the reference SOC, the battery 4 is charged. The power generation cost reference value is a reference for permitting charging of the battery 4. For example, when the power generation cost falls below the power generation cost reference value, charging of the battery 4 is permitted.

  In addition, the control unit 9 is connected to the battery capacity calculation unit 7, the power consumption calculation unit 8, and the power generation cost calculation unit 10, and the calculated SOC1, SOC2, power consumption amount, and power generation cost are input thereto.

  Then, the control unit 9 sets a predetermined reference SOC in the capacity reference value setting unit 11 in accordance with the power consumption calculated by the power consumption calculation unit 8.

  Further, when the power generation cost calculated by the power generation cost calculation unit 10 is smaller than a predetermined power generation cost reference value, the control unit 9 calculates the battery (main battery 4a, sub battery 4b) 4 calculated by the battery capacity calculation unit 7. When the SOC is lower than the reference SOC, the power generation command unit 13 issues a power generation command to the generator 3.

  Further, in the control unit 9, the power generation cost reference value setting unit 12 sets the power generation cost reference value according to the power consumption calculated by the power consumption calculation unit 8.

  In the present embodiment, the control unit 9 sets the reference SOC-m of the main battery 4a and the reference SOC-s of the sub battery 4b for each of the main battery 4a and the sub battery 4b.

  The control unit 9 permits power generation when the power generation cost calculated by the power generation cost calculation unit 10 is smaller than the power generation cost reference value. Here, when the vehicle electrical load is large, the power generation cost reference value is increased. As a result, the frequency of power generation increases, and the frequency of charging the main battery 4a that seems to be discharged increases.

  Below, the process of the charge control to the battery 4 (the main battery 4a and the sub battery 4b) performed by the vehicle power supply control device 6 will be described using the flowchart shown in FIG.

  In step S <b> 10, the battery capacity calculation unit 7 calculates the current charge amount of the main battery 4 a and the sub battery 4 b, that is, SOC, and sends the calculation result to the control unit 9.

  In step S <b> 11, the power generation cost calculation unit 10 calculates the fuel consumption (power generation cost) per unit power generation from the engine speed, engine torque, fuel consumption rate, and the like, and sends the calculation result to the control unit 9. .

  In step S12, the power consumption calculation unit 8 adds up the power consumption amounts of the components operating for the components (electrical components) connected to the main battery 4a and the sub-battery 4b, respectively. Each vehicle electrical load is calculated. Individual power consumption in each component is measured in advance, whether each component has started operation (whether it has been turned on) or not, and sums the power consumption of each component in the ON state. The power consumption for each battery 4a, 4b is calculated. The power consumption calculation unit 8 adds up the vehicle electrical loads calculated for each battery (main battery 4a, sub-battery 4b) 4, finds the electrical load of the entire vehicle, and sends the result of the addition to the control unit 9.

  In step S <b> 13, the control unit 9 sets a power generation cost reference value according to the power consumption calculated by the power consumption calculation unit 8.

  In the diagram showing the relationship between the power generation cost (g / kW) and the engine torque shown in FIG. 4, for example, when the power generation cost reference value is when the power consumption is 100 W, the engine torque area is A and the power consumption is 200 W. When the power generation cost reference value is set at the time of, the engine torque region is B. Regions A and B indicate engine torque regions in which power generation is permitted. If the power consumption increases, the power generation cost reference value increases accordingly, and the engine torque region in which power generation is permitted increases. Thereby, when the power generation cost reference value is raised, the frequency of power generation increases.

  In step S14, the control unit 9 sets the reference SOC-m and SOC-s for the main battery 4a and the sub battery 4b according to the power consumption calculated by the power consumption calculation unit 8.

Here, the setting of the reference SOC of the main battery 4a will be described as an example for setting the reference SOC.
FIG. 3 is a diagram showing the relationship between the SOC of the battery 4a and the vehicle electrical load. For example, the reference SOC-m is the reference value shown in the diagram C until the vehicle electrical load is 100 W, the reference value shown in the diagram D is up to 200 W when it exceeds 100 W, and is shown in the diagram E when it exceeds 200 W. This is the reference value. That is, the reference SOC-m is raised as the electric load of the vehicle increases. As a result, the larger the electric load, the faster the charging of the main battery 4a, and the main battery 4a is in an appropriate charged state.

  Further, in FIG. 4, a diagram F shows a reference value of the main battery 4a when idling stop is prohibited. If the SOC 1 of the main battery 4a falls below the reference value (denoted as IS prohibited SOC in the figure) shown in the diagram F, the vehicle cannot stop idling. That is, since it becomes impossible to obtain the power necessary for starting the engine from the state where idling is stopped from the main battery 4a, when SOC1 falls below the reference value shown in the diagram F, idling stop is prohibited.

  In step S15, the control unit 9 determines whether or not the current power generation cost of the vehicle calculated by the power generation cost calculation unit 10 is smaller than the power generation cost reference value. When it is determined that the current power generation cost of the vehicle is larger than the power generation cost reference value (in the case of NO), the process proceeds to step S16, and all the batteries (main battery 4a and sub battery 4b) 4 are not charged. The generator 3 is controlled. As a result, when the current power generation cost of the vehicle is high, the battery (main battery 4a, sub-battery 4b) 4 is not charged so that no further fuel is consumed for charging. .

  In step S15, when the control unit 9 determines that the current power generation cost is smaller than the power generation cost reference value, the control unit 9 proceeds to step S17.

  In step S17, control unit 9 determines whether or not current SOC2 of sub battery 4b calculated by battery capacity calculation unit 7 is greater than reference SOC-s set in step S14. In step S17, when it is determined that the SOC2 of the sub-battery 4b of the current vehicle is larger than the reference SOC-s, the control unit 9 determines that the SOC1 of the main battery 4a of the current vehicle 1 is the reference SOC- in step S18. It is judged whether it is smaller than m.

  That is, when it is determined in step S17 that SOC2 of sub battery 4b of the current vehicle is larger than reference SOC-s, sub battery 4b has sufficient power to supply power to the vehicle electrical load. It means that it is in a charged state.

  When determining in step S18 that SOC1 of main battery 4a of the current vehicle is greater than reference SOC-m, control unit 9 executes step S16. In this case, since the main battery 4a and the sub battery 4b are both charged above the reference SOC, the batteries 4a and 4b are not charged. In step S18, if the SOC 1 of the current main battery 4a of the vehicle 1 is smaller than the reference SOC-m, the control unit 9 generates power for the generator 3 so as to charge the main battery 4a in step S19. Make a command. Thereby, the main battery 4a is charged.

  In step S17, when the control unit 9 determines that the SOC2 of the sub-battery 4b of the current vehicle is smaller than the reference SOC-s, the control unit 9 proceeds to step S20.

  In step S20, control unit 9 determines whether or not SOC1 of current main battery 4a of the vehicle is smaller than reference SOC-m. When it is determined that SOC1 of main battery 4a of the current vehicle is greater than reference SOC-m, control unit 9 executes step S21.

  That is, in step S20, when it is determined that SOC1 of main battery 4a of the current vehicle is larger than reference SOC-m, main battery 4a has sufficient power to supply power to the vehicle electrical load. It means that. Therefore, in step S21, the control unit 9 issues a power generation command to the generator 3 so as to charge the sub battery 4b having a capacity smaller than the reference SOC-m. Thereby, the sub battery 4b is charged.

  When determining in step S20 that the SOC 1 of the main battery 4a is smaller than the reference SOC-m, the control unit 9 determines that both the capacities of the main battery 4a and the sub-battery 4b have decreased, and step S22. Execute. In step S22, the control unit 9 issues a power generation command to the generator 3 so that both the main battery 4a and the sub battery 4b are charged. Thereby, both the main battery 4a and the sub battery 4b are charged.

  The above steps S10 to S22 are repeatedly executed, and the power generation cost reference value, the reference SOC-m, and the reference SOC-s are set in steps S13 and 14 according to the power consumption of the vehicle calculated in step S12. . And charging to the main battery 4a and the sub battery 4b is controlled by step S15-step S22.

The vehicle power supply control device 6 according to the present embodiment used in the vehicle 1 includes a battery capacity calculation unit 7 that detects the remaining capacity of the power of the batteries 4a and 4b, and a power consumption that calculates the power consumption of the electric load. A calculation unit 8 and a control unit 9 for instructing the generator 3 to generate power so that the batteries 4a and 4b are charged when the remaining capacity detected by the battery capacity calculation unit 7 falls below a predetermined capacity reference value. I have.
The control unit 9 sets a capacity reference value (reference SOC) according to the power consumption calculated by the power consumption calculation unit 8.

Further, the vehicle power supply control device 6 according to the present embodiment has a power generation cost that indicates the amount of fuel consumed by the engine 2 in order for the generator 3 to generate power relative to the amount of power generated by the generator 3. The power generation cost calculation unit 10 is calculated. The control unit 9 permits power generation by the generator 3 when the power generation cost calculated by the power generation cost calculation unit 10 is smaller than a predetermined power generation cost reference value.
In addition, the control unit 9 sets a power generation cost reference value according to the power consumption calculated by the power consumption calculation unit 8.

  Moreover, the vehicle power supply control device 6 according to the present embodiment is equipped with at least two batteries 4a and 4b, and the batteries 4a and 4b supply power to different electric loads 5a and 5b, respectively, and a power consumption calculation unit. 8 calculates the amount of power consumed by the electric loads 5a and 5b for each of the batteries 4a and 4b, and the control unit 9 sets a capacity reference value for the batteries 4a and 4b for each of the batteries 4a and 4b.

  As described above, according to the present embodiment, the control unit 9 uses the reference SOC as a reference for whether or not to charge the batteries 4a and 4b according to the power consumption calculated by the power consumption calculation unit 8. Therefore, even when the amount of power consumed by the electric load 5 of the vehicle 1 is large, the state of charge of the battery (main battery 4a, sub battery 4b) 4 can be maintained in an appropriate state.

  Further, according to the present embodiment, when the power generation cost calculated by the power generation cost calculation unit 10 is smaller than the power generation cost reference value, the control unit 9 uses the SOC of the battery 4 calculated by the battery capacity calculation unit 7 as a reference. Since the power generation command is issued to the generator 3 when the SOC is lower than the SOC, the amount of fuel consumed for generating power can be further reduced.

  Moreover, according to this Embodiment, since the control part 9 sets a power generation cost reference value according to the power consumption calculated by the power consumption calculation part 8, the charge condition of the battery 4 is maintained in a suitable charge condition. be able to.

  Moreover, according to this Embodiment, the battery 4 can be charged early by raising the reference | standard SOC of the battery 4, so that the electric load 5 of the vehicle 1 is large. Moreover, the range which permits electric power generation can be expanded by raising electric power generation cost reference value, so that the electric load 5 is large, and the frequency of charge to the battery 4 can be increased in connection with this.

  Since the main battery 4a and the sub-battery 4b having different charging characteristics can be maintained at appropriate SOCs, for example, a decrease in the frequency of idling stops can be avoided. Here, in a state where the SOC 1 of the main battery 4a is small, it is necessary to continue driving the engine 2 because it is necessary to charge the main battery 4a, and idling stop cannot be performed. For this reason, when the SOC of the main battery 4a is small, the frequency of idling stop is reduced. In the present embodiment, since the SOCs of the main battery 4a and the sub battery 4b can be maintained in an appropriate state, the above-described problem does not occur, and a decrease in the frequency of idling stops can be prevented.

  Furthermore, since the main battery 4a and the sub battery 4b having different charging characteristics can be kept at appropriate SOCs, the main battery 4a and the sub battery 4b can leave appropriate amounts of power generated by regeneration during deceleration. That is, if only one of the main battery 4a and the sub battery 4b is fully charged, there is a possibility that the electric power that can be regenerated may be reduced, but in this embodiment, the remaining capacity of both batteries is kept in an appropriate charged state. Therefore, charging by regeneration is not wasted, and fuel consumption can be improved.

  Further, according to the present embodiment, when the two batteries of the main battery 4a and the sub battery 4b are mounted, the charging state of the main battery 4a and the sub battery 4b according to the power consumption consumed by the electric load 5 of the vehicle. Can be kept in an appropriate state with a good balance. That is, even if the battery has different charging characteristics, by changing the reference SOC of the main battery 4a and the sub-battery 4b according to the electric load 5 of the vehicle, one of the batteries becomes overcharged or feels discharged. It can be charged in a well-balanced manner.

  In the embodiment described above, the power control of the main battery 4a and the sub battery 4b having two different charging characteristics has been described as the power source. However, the vehicle power control device 6 according to the present invention is a power source for one battery. The present invention can also be applied to control, and can also be applied to power control of three or more batteries.

  Moreover, you may calculate vehicle power consumption based on the electric current value measured with the ammeter attached to battery 4a, 4b.

  Further, in the above-described embodiment, the reference SOC is set as a reference for determining whether or not the main battery 4a and the sub battery 4b are charged according to the power consumption calculated by the power consumption calculation unit 8, and the charging is controlled. In addition to the vehicle power consumption, the reference SOC and the power generation cost reference value may be changed when a specific component (electrical component) is turned on. In this case, for example, when the light is turned on, the reference SOC may be raised to xx%, and the power generation cost reference value may be changed to xx [g / kw].

  Although the embodiments of the present invention have been disclosed as described above, it is obvious that those skilled in the art can make changes without departing from the scope of the present invention. All such modifications and equivalents are intended to be included in the following claims.

1 vehicle 2 engine (internal combustion engine)
3 Generator 4 Battery (Power)
DESCRIPTION OF SYMBOLS 5 Electric load 6 Vehicle power supply control device 7 Battery capacity calculation part 8 Power consumption calculation part 9 Control part 10 Electric power generation cost calculation part

Claims (4)

An internal combustion engine;
A generator driven by the driving force of the internal combustion engine to generate electricity;
A power source that is supplied with power from the generator and charged;
An electric load driven by power supplied from the power source;
In a vehicle power supply control device used for a vehicle equipped with
A power source capacity calculation unit for detecting a remaining capacity of the power of the power source;
A power consumption calculation unit for calculating the power consumption of the electrical load;
A control unit for instructing the generator to generate power so as to charge the power source when the remaining capacity detected by the power source capacity calculation unit is lower than a predetermined capacity reference value;
The vehicle power supply control device, wherein the control unit sets the capacity reference value according to the power consumption calculated by the power consumption calculation unit. A power generation cost calculation unit that calculates a power generation cost indicating the amount of fuel consumed by the internal combustion engine in order to generate power by the generator with respect to the amount of power generated by the generator;
2. The vehicle power source according to claim 1, wherein when the power generation cost calculated by the power generation cost calculation unit is smaller than a predetermined power generation cost reference value, the control unit permits power generation by the generator. Control device.   The vehicle power supply control device according to claim 1, wherein the control unit sets the power generation cost reference value according to the power consumption calculated by the power consumption calculation unit. With at least two power supplies,
Each power source supplies power to the different electric loads,
The power consumption calculation unit calculates the power consumption of the electric load for each power source,
The vehicular power supply control device according to any one of claims 1 to 3, wherein the control unit sets the capacity reference value for each power supply.

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