JP6515858B2 - vehicle - Google Patents

Description

  The present invention relates to a vehicle, and more particularly to a vehicle provided with a converter connected between a main battery and an accessory battery.

  JP 2012-249462 A (Patent Document 1) discloses a vehicle provided with a high voltage battery, a low voltage battery, and a converter. The high voltage battery stores the power supplied to the motor that generates the traveling drive force of the vehicle. The low voltage battery stores the power supplied to the accessory provided in the vehicle. The converter performs voltage conversion between the high voltage battery and the low voltage battery. In this vehicle, the output current of the converter is controlled such that the ratio of the output power to the input power of the converter is maximized. According to this vehicle, the converter can be driven with high efficiency.

JP 2012-249462 A

  However, in the process of charging and discharging the main battery and the auxiliary battery (including voltage conversion by the converter), not only the power loss in the converter but also the power loss in the internal resistances of the main battery and the auxiliary battery. Therefore, even if the converter is controlled such that the ratio of output power to input power of the converter is maximum as in the vehicle disclosed in Patent Document 1, power loss in the main battery and auxiliary battery is not taken into consideration. The power supply system as a whole may not have the maximum energy efficiency.

  The present invention has been made to solve such a problem, and an object thereof is to provide the energy efficiency of the entire power supply system in a vehicle provided with a converter connected between a main battery and an auxiliary battery. It is to improve.

  A vehicle according to one aspect of the present invention comprises a motor, a main battery, an accessory, an accessory battery, a converter, a first current sensor, a second current sensor, a first voltage sensor, And a control device. The motor generates a traveling drive force of the vehicle. The main battery stores the power supplied to the motor. The accessory battery stores power supplied to the accessory. The converter is connected between the main battery and the accessory battery. The first current sensor senses a first current indicative of the current of the main battery. The second current sensor senses a second current indicative of the accessory current. The first voltage sensor detects a first voltage that indicates the voltage of the main battery. The second voltage sensor detects a second voltage indicative of the voltage of the auxiliary battery. The memory is a ratio of the first and second voltages, the first and second currents, and the current of the accessory battery when the efficiency of the power supply system including the main battery, the accessory battery, and the converter is maximized. Store a map showing the relationship with The control device controls the converter such that the current of the accessory battery becomes a value determined from the outputs of the first and second current sensors, the outputs of the first and second voltage sensors, and the map.

  Thus, in this vehicle, the above-mentioned map (considering the efficiency of the power supply system including the main battery, the accessory battery, and the converter) is used to control the converter. Therefore, according to this vehicle, it is possible to improve the energy efficiency of the entire power supply system including the main battery, the accessory battery, and the converter.

  A vehicle according to another aspect of the present invention includes an engine, a motor, a main battery, an accessory, an accessory battery, a converter, a current sensor, a first voltage sensor, and a second voltage sensor. A memory and a control device are provided. The motor generates a traveling drive force of the vehicle. The main battery stores the power supplied to the motor. The accessory battery stores power supplied to the accessory. The converter is connected between the main battery and the accessory battery. The current sensor detects the current of the main battery. The first voltage sensor detects a first voltage that indicates the voltage of the main battery. The second voltage sensor detects a second voltage indicative of the voltage of the auxiliary battery. The memory stores the first and second maps. The controller controls the converter. The first map shows the ratio of the first and second voltages and the current of the main battery when the efficiency of the power supply system including the main battery, the accessory battery, and the converter is maximized during operation of the engine; The relationship with the current of the auxiliary battery is shown. The second map shows the relationship between the ratio of the first and second voltages, the current of the main battery, and the current of the auxiliary battery when the efficiency of the power supply system is maximum while the engine is stopped. The control device controls the converter such that the current of the accessory battery becomes the value determined from the output of the current sensor, the outputs of the first and second voltage sensors, and the first map, while the engine is operating. On the other hand, while the engine is stopped, the converter is controlled so that the current of the auxiliary battery becomes the value determined from the output of the current sensor, the outputs of the first and second voltage sensors, and the second map. .

  The current of the accessory can be roughly predicted depending on whether the engine is operating. In this vehicle, the first or second map is used to control the converter, depending on whether the engine is operating or not. In the first and second maps, the current of the accessory estimated based on whether or not the engine is operating is reflected respectively. Therefore, according to this vehicle, the output of the current sensor (detecting the current of the main battery) and the outputs of the first and second voltage sensors are used without actually detecting the current of the accessory. The energy efficiency of the entire power supply system including the main battery, the accessory battery, and the converter can be improved.

  A vehicle according to another aspect of the present invention includes a motor, a main battery, an accessory, an accessory battery, a converter, a current sensor, a first voltage sensor, a second voltage sensor, and a control device. Equipped with The motor generates a traveling drive force of the vehicle. The main battery stores the power supplied to the motor. The accessory battery stores power supplied to the accessory. The converter is connected between the main battery and the accessory battery. The current sensor detects the current of the main battery. The first voltage sensor detects a first voltage that indicates the voltage of the main battery. The second voltage sensor detects a second voltage indicative of the voltage of the auxiliary battery. The controller controls the converter. The control device stops the converter when the main battery is discharged, and controls the converter so that the current of the auxiliary battery becomes a value obtained from a predetermined equation prepared in advance, when the main battery is charged. The predetermined equation is the ratio of the first and second voltages, the current of the main battery, the converter conversion efficiency, the current of the accessory battery, and the like when the power loss of the main battery and the accessory battery is minimized. Show the relationship between

  When the output power of the converter is increased when the main battery is discharged, the output power of the main battery is increased, so the power loss in the internal resistance of the main battery is increased. As a result, the energy efficiency of the entire power supply system is reduced. In this vehicle, control is performed to stop the converter when the main battery is discharged. Therefore, according to this vehicle, it is possible to improve the energy efficiency of the entire power supply system when the main battery is discharged.

  On the other hand, when the output power of the converter is increased at the time of charging the main battery, the input power of the main battery is reduced, so that the power loss in the internal resistance of the main battery is reduced. In addition, when the output current of the converter is increased to a certain extent during charging of the main battery, the conversion efficiency of the converter does not fluctuate significantly. Therefore, in this case, the power loss in the main battery and the auxiliary battery greatly affects the energy efficiency of the power supply system. In this vehicle, at the time of charging of the main battery, the converter is controlled such that the power loss of the main battery and the accessory battery is minimized. Therefore, according to this vehicle, it is possible to improve the energy efficiency of the entire power supply system at the time of charging of the main battery.

  According to the present invention, in the vehicle provided with the converter connected between the main battery and the accessory battery, the energy efficiency of the entire power supply system can be improved.

Fig. 1 is a block diagram showing a configuration of a vehicle according to a first embodiment. It is a figure which shows the relationship between a power supply system, load, and an auxiliary machine. It is a figure showing the relation between a power supply system, load, accessories, and an engine. It is a figure which shows the relationship between a power supply system, load, and an auxiliary machine, when an engine is off and at the time of charge of a main battery. It is a figure which shows the relationship (at the time of charge of a main battery) of conversion efficiency, Pb1loss, and Pb2loss in case the output current of a DCDC converter is 50A. It is a figure which shows the relationship (at the time of charge of a main battery) of conversion efficiency, Pb1loss, and Pb2loss in case the output current of a DCDC converter is 60A. It is a figure which shows the relationship between a power supply system, a load, and an auxiliary machine, when an engine is off and the time of discharge of the main battery. It is a figure which shows the relationship (at the time of discharge of a main battery) of conversion efficiency, Pb1loss, and Pb2loss in case the output current of a DCDC converter is 50A. It is a figure which shows the relationship (at the time of discharge of a main battery) of conversion efficiency, Pb1loss, and Pb2loss in case the output current of a DCDC converter is 60A. It is a figure which shows the relationship between a power supply system, a load, an auxiliary machine, and an engine in the time of an engine in an ON state, and the time of charge of a main battery. It is a figure which shows the relationship of conversion loss, Pb1loss, Pb2loss, and loss in an engine in case the output current of a DCDC converter is 20A. It is a figure which shows the relationship of conversion loss, Pb1loss, Pb2loss, and loss in an engine in case the output current of a DCDC converter is 50A. FIG. 6 is a diagram for describing a map used for control of the DCDC converter in the first embodiment. It is a flowchart for demonstrating the control processing procedure of a DCDC converter. FIG. 16 is a diagram for describing a map used for control of a DCDC converter in the second embodiment. It is a flowchart for demonstrating the control processing procedure of a DCDC converter. FIG. 16 is a flowchart for illustrating control processing procedures of the DCDC converter in the third embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference characters and description thereof will not be repeated.

Embodiment 1
[Configuration of hybrid vehicle]
FIG. 1 is a block diagram showing a configuration of a vehicle according to a first embodiment of the present invention. Referring to FIG. 1, hybrid vehicle 1 includes an engine 150, a load 135 (including motor generators 140 and 145), a power split device 155, a transmission gear 160, a drive wheel 170, and a power supply system 10. , An accessory 400, a memory 500, and an ECU (Electronic Control Unit) 600. Hybrid vehicle 1 can travel by a driving force output from at least one of engine 150 and motor generator 140.

  The engine 150 converts thermal energy due to fuel combustion into kinetic energy of a moving element such as a piston or a rotor, and outputs the converted kinetic energy to the power split device 155. For example, if the mover is a piston and its movement is a reciprocating motion, the reciprocating motion is converted to rotational motion through a so-called crank mechanism, and kinetic energy of the piston is transmitted to the power split device 155.

  Power split device 155 is configured to be able to split the driving force generated by engine 150 into a driving force for driving drive wheel 170 and a driving force for driving motor generator 145. The driving force for driving drive wheel 170 is transmitted from power split device 155 to drive wheel 170 through transmission gear 160. Power split device 155 is formed of, for example, a planetary gear.

  Load 135 includes PCU 130 and motor generators 140 and 145. PCU 130 is connected between main battery 100 (described later) and motor generators 140 and 145, and performs power conversion between main battery 100 and motor generators 140 and 145. PCU 130 includes, for example, two inverters (not shown). One of the inverters converts the power generated by motor generator 145 into DC power and outputs the DC power to main battery 100. This inverter converts DC power supplied from main battery 100 into AC power and outputs it to motor generator 145 when engine 150 is started.

  The other inverter converts DC power supplied from main battery 100 into AC power and outputs the AC power to motor generator 140. The inverter converts the electric power generated by the motor generator 140 into DC electric power and outputs the electric power to the main battery 100 when braking the hybrid vehicle 1 or reducing the acceleration on the downward slope.

  Motor generators 140 and 145 are AC motors, and are formed of, for example, a three-phase AC synchronous motor in which permanent magnets are embedded in a rotor. Motor generator 145 converts kinetic energy generated by engine 150 into electrical energy and outputs the electrical energy to PCU 130. In addition, motor generator 145 generates driving force by the three-phase AC power received from PCU 130 to start engine 150.

  Motor generator 140 generates traveling driving force of hybrid vehicle 1 by the three-phase AC power received from PCU 130. The motor generator 140 converts mechanical energy stored in the vehicle as kinetic energy or potential energy into electrical energy and outputs the electrical energy to the PCU 130 when braking the hybrid vehicle 1 or reducing the acceleration on the downward slope.

  The power supply system 10 supplies two types of voltages, high voltage and low voltage, to each device mounted on the hybrid vehicle 1. The power supply system 10 includes a high voltage main battery 100 and a low voltage auxiliary battery 200. Power supply system 10 further includes current sensors 110, 210, 410, voltage sensors 120, 220, and DCDC converter 300.

  Main battery 100 is a rechargeable DC power source, and is formed of, for example, a secondary battery such as a nickel hydrogen battery or a lithium ion battery. Main battery 100 supplies power to PCU 130 and DCDC converter 300. Main battery 100 is charged by receiving generated electric power when motor generators 140 and 145 generate electric power. The rated output voltage of main battery 100 is, for example, about 200V.

  Current sensor 110 is provided on the positive electrode of power line pair 125. The current sensor 110 detects an output current I1 of the main battery 100. Voltage sensor 120 is connected between power line pair 125. Voltage sensor 120 detects voltage V 1 of main battery 100. The detection results of current sensor 110 and voltage sensor 120 are output to ECU 600. The output current I1 of the main battery 100 indicates a positive value (I1> 0) when the main battery 100 is discharged, and indicates a negative value (I1 <0) when the main battery 100 is charged.

  DCDC converter 300 steps down the voltage between power line pair 125 and outputs it to power line pair 225. The output voltage of DCDC converter 300 is controlled in accordance with an instruction from ECU 600. In hybrid vehicle 1 according to the first embodiment, DCDC converter 300 is controlled such that the efficiency of power supply system 10 is maximized. The control of the DCDC converter 300 will be described in detail later.

  Auxiliary device battery 200 is a rechargeable DC power source, and is formed of, for example, a secondary battery such as a lead storage battery or a lithium ion battery. Auxiliary battery 200 supplies power to auxiliary device 400. Auxiliary battery 200 is charged by receiving power from main battery 100 through DCDC converter 300. The rated output voltage of auxiliary battery 200 is, for example, about 12V.

  Current sensor 210 is provided on the positive electrode of power line pair 225. Current sensor 210 senses output current I2 of auxiliary battery 200. Voltage sensor 220 is connected between power line pair 225. Voltage sensor 220 detects voltage V 2 of auxiliary battery 200. The detection results of current sensor 210 and voltage sensor 220 are output to ECU 600. The output current I2 of the auxiliary battery 200 indicates a positive value (I2> 0) when the auxiliary battery 200 is discharged, and indicates a negative value (I2 <0) when the auxiliary battery 200 is charged.

  Current sensor 410 is provided on the power line between the positive electrode of power line pair 225 and accessory 400. Current sensor 410 detects an input current to accessory 400. The detection result of current sensor 410 is output to ECU 600. It is assumed that input current I3 of accessory 400 indicates a positive value (I3> 0) when flowing into accessory 400. Since current does not flow from accessory 400 to DCDC converter 300 or accessory battery 200, input current I3 does not show a negative value.

  Auxiliary device 400 is connected to DCDC converter 300 and auxiliary battery 200 through the positive electrode of power line pair 225. Auxiliary device 400 is driven using the power supplied from DCDC converter 300 and / or auxiliary battery 200. Auxiliary equipment 400 includes, for example, a small motor for wiper or door opening / closing, an audio device, an air conditioner, and the like.

  Memory 500 is configured of, for example, a non-volatile memory such as a flash memory. The memory 500 stores a map used when controlling the DCDC converter 300. This map shows the relationship between the voltage ratio of main battery 100 and accessory battery 200, the current of main battery 100 and accessory 400, and the current of accessory battery 200 when the efficiency of power supply system 10 is maximized. Show. This map will be described in more detail later.

  The ECU 600 includes a central processing unit (CPU), a storage device, an input / output buffer and the like (all not shown) and controls each device in the hybrid vehicle 1. Note that this control is not limited to the processing by software, but may be processed by dedicated hardware (electronic circuit).

[Improvement of overall efficiency of power supply system]
In the hybrid vehicle 1 described above, in order to increase the energy efficiency at the time of operation of the DCDC converter 300, the DCDC converter 300 is controlled such that the ratio of the output power to the input power of the DCDC converter 300 (conversion efficiency) is maximized. Is considered.

  However, in the process of charging / discharging of main battery 100 and auxiliary battery 200 accompanied by operation of DCDC converter 300 (hereinafter, also referred to as “charging / discharge accompanied by operation of DCDC converter 300”), DCDC converter 300 Not only the power loss but also power loss in the internal resistance of main battery 100 and auxiliary battery 200 may occur. Therefore, even if DCDC converter 300 is controlled such that the ratio of output power to input power of DCDC converter 300 is maximized, power loss in main battery 100 and auxiliary battery 200 is not taken into consideration, and power supply system 10 as a whole Energy efficiency may not be maximized.

  Therefore, in hybrid vehicle 1 according to the first embodiment, memory 500 has the voltage ratio between main battery 100 and auxiliary battery 200 when the efficiency of power supply system 10 is maximized, and that of main battery 100 and auxiliary device 400. A map indicating the relationship between the current and the current of auxiliary battery 200 is stored. Then, ECU 600 controls DC-DC converter 300 such that the current of auxiliary battery 200 becomes the output of current sensors 110 and 410, the outputs of voltage sensors 120 and 220, and the target current derived from the map.

  As described above, in the hybrid vehicle 1, the target value of the current of the auxiliary battery 200 is derived using the map indicating the relationship between various values when the efficiency of the entire power supply system 10 is maximized, and the auxiliary battery 200 is The DC-DC converter 300 is controlled such that the current at the target value becomes the target value. Therefore, according to this hybrid vehicle 1, the energy efficiency of the entire power supply system 10 can be improved. Hereinafter, first, the index used when creating this map will be described.

[Indicator indicating the efficiency of the entire power system]
FIG. 2 is a diagram showing the relationship between the power supply system 10, the load 135, and the accessory 400. With reference to FIG. 2, among the above maps, an indicator for creating a map that is used while the engine 150 is stopped will be described. The index described here does not simply indicate the conversion efficiency (output power / input power) of the DCDC converter 300, but the power consumption of the entire power supply system 10 considering the power consumption in the internal resistances of the main battery 100 and the auxiliary battery 200. It shows the efficiency.

  The output power based on the electromotive force of the main battery 100 at the time of charge and discharge accompanying the operation of the DCDC converter 300 is Pb1, and the power consumption at the internal resistance of the main battery 100 is Pb1loss. The input power to the load 135 is Pload1. Then, the output power based on the electromotive force of the auxiliary battery 200 at this time is Pb2, and the power consumption at the internal resistance of the auxiliary battery 200 is Pb2 loss. The input power to the accessory 400 is Pload2.

  In the first embodiment, an index represented by the following equation (1) indicates the efficiency of the entire power supply system 10 during charging and discharging while the engine 150 is stopped and the DCDC converter 300 is operated. It is assumed.

ηe = (Pload2-Pb2) / (Pb1-Pload1) (1)
In the equation (1), the denominator includes the power consumption (Pb1 loss) in the internal resistance of the main battery 100, and the numerator includes the power consumption (Pb2 loss) in the internal resistance of the auxiliary battery 200. That is, according to this equation (1), it is possible to indicate the energy efficiency of the entire power supply system 10 in which the power consumption in the internal resistances of the main battery 100 and the auxiliary battery 200 is taken into consideration. In the first embodiment, a map for stopping the engine 150 is created using 停止 e.

  When the current of main battery 100, the current of auxiliary device 400, and the voltage ratio of main battery 100 and auxiliary battery 200 are given, η e is uniquely determined when the current of auxiliary battery 200 is determined. The map for stopping the engine 150 is the case where ηe is maximum for the combination of the current of the main battery 100, the current of the accessory 400, and the voltage ratio of the main battery 100 and the accessory battery 200. It is generated by identifying the current of auxiliary battery 200 in advance by experiment.

  That is, this map shows the relationship between the voltage ratio of main battery 100 and auxiliary battery 200, the current of main battery 100 and auxiliary device 400, and the current of auxiliary battery 200 when η e is maximum. Therefore, in hybrid vehicle 1, when the outputs of current sensors 110 and 410 and the outputs of voltage sensors 120 and 220 are obtained while engine 150 is stopped, the target of auxiliary battery 200 for maximizing η e is obtained. The current can be determined.

  FIG. 3 is a diagram showing the relationship among power supply system 10, load 135, accessory 400, and engine 150. As shown in FIG. With reference to FIG. 3, among the above maps, an index for creating a map used during operation of engine 150 will be described. The indicators described here indicate the power consumption in the internal resistances of the main battery 100 and the accessory battery 200, and the efficiency of the entire power supply system 10 in consideration of losses in the engine 150 and the load 135.

  The Pb1, Pb1 loss, Pload1, Pb2, Pb2 loss, and Pload2 are the same as in FIG. The fuel heating value for operating the engine 150 is represented by Qfc, and the output power of the engine 150 is represented by Pe. The driving power at the load 135 is Pv, and the loss at the load 135 is Pvloss.

  In the first embodiment, the index represented by the following equation (2) indicates the efficiency of the entire power supply system 10 during operation of engine 150 and at the time of charge and discharge with operation of DCDC converter 300. It is assumed.

η e eng = (Pv-Pb1-Pb2 + Pload2) / Qfc (2)
In this equation (2), the denominator includes the loss in engine 150 and load 135, and the numerator includes the power consumption in the internal resistance of main battery 100 and auxiliary battery 200. That is, according to this equation (2), it is possible to indicate the power loss in the internal resistance of main battery 100 and auxiliary battery 200, and the energy efficiency of the entire power supply system 10 in which the loss in engine 150 and load 135 is taken into consideration. it can. In the first embodiment, ηe_eng is used to create a map for the operation of engine 150.

  It is assumed that Qfc and Pv are given in advance. In this case, when the current of main battery 100, the current of auxiliary device 400, and the voltage ratio of main battery 100 and auxiliary battery 200 are given, ηe_eng is uniquely determined when the current of auxiliary battery 200 is determined. It is decided. The map for the operation of engine 150 is the case where ηe_eng is maximum for the combination of the current of main battery 100, the current of accessory 400, and the voltage ratio of main battery 100 and accessory battery 200. It is generated by identifying the current of auxiliary battery 200 in advance by experiment.

  That is, the map used during operation of engine 150 is the voltage ratio of main battery 100 and auxiliary battery 200, the current of main battery 100 and auxiliary device 400, and auxiliary battery 200 when ηe_eng is maximum. The relationship with the current is shown. Therefore, in hybrid vehicle 1, when outputs of current sensors 110 and 410 and outputs of voltage sensors 120 and 220 are obtained during operation of engine 150, a target of auxiliary battery 200 for maximizing ηe_eng. The current can be determined.

  Details of each of the above maps will be described later. Hereinafter, first, it will be illustrated how the index ee and ηe_eng change depending on various conditions.

[Example of efficiency of entire power supply system (engine off and main battery charging)]
FIG. 4 is a diagram showing the relationship between power supply system 10, load 135 and accessory 400 when engine 150 is off and main battery 100 is charged. Referring to FIG. 4, for example, it is assumed that the input voltage of DC-DC converter 300 is 200 V, the output voltage is 10 V, and Pload1 is -20000 W (the output power from load 135 is 20000 W). In this case, the current (Iload1) of the load 135 is −100 A (the output current from the load 135 is 100 A). Let Pload2 be 200 W, and the current (Iload2) of the accessory 400 be 20 A. The internal resistance of main battery 100 is 0.1Ω, and the internal resistance of auxiliary battery 200 is 0.01Ω.

  During charging of the main battery 100, when the output current of the DCDC converter 300 increases, the current flowing into the DCDC converter 300 in Iload1 increases, so the current (absolute value) flowing into the main battery 100 decreases. Therefore, the power consumption in the internal resistance of main battery 100 is reduced.

  When the output current of DCDC converter 300 increases in the range where the output current of DCDC converter 300 is less than or equal to Iload2, the output current from auxiliary battery 200 to auxiliary device 400 decreases. Therefore, the power consumption in the internal resistance of auxiliary battery 200 is reduced. On the other hand, when the output current of DCDC converter 300 increases in the range where the output power of DCDC converter 300 exceeds Iload2, the input current (absolute value) to auxiliary battery 200 increases. Therefore, the power consumption in the internal resistance of auxiliary battery 200 is increased.

  The conversion efficiency (output power / input power) of the DCDC converter 300 increases until the output current of the DCDC converter 300 reaches a predetermined value, and gradually decreases when the output current exceeds the predetermined value.

  FIG. 5 is a diagram showing the relationship between the conversion efficiency of the DCDC converter 300, Pb1loss, and Pb2loss (when the main battery 100 is charged) when the output current of the DCDC converter 300 is 50A. Referring to FIG. 5, the horizontal axis in the upper drawing shows the output current of DCDC converter 300, and the vertical axis shows the conversion efficiency of DCDC converter 300. The horizontal axis of the middle figure shows the output current of the DCDC converter 300, and the vertical axis shows Pb1 loss. The horizontal axis of the lower figure shows the output current of the DCDC converter 300, and the vertical axis shows Pb2loss. In this example, it is assumed that the conversion efficiency of the DCDC converter 300 is 85% when the output current of the DCDC converter 300 is 50A.

  Under the above conditions, Pb1 and Pb2 can be derived. By using the derived value, the above condition, and the above equation (1), it is possible to derive ηe when the output current of the DCDC converter 300 is 50 A when the main battery 100 is charged. In this case, η e is approximately 0.32.

  FIG. 6 is a diagram showing the relationship between the conversion efficiency of the DCDC converter 300, Pb1loss, and Pb2loss (when the main battery 100 is charged) when the output current of the DCDC converter 300 is 60A. Referring to FIG. 6, the horizontal axis and the vertical axis of each drawing are the same as FIG. In this example, it is assumed that the conversion efficiency of the DCDC converter 300 is 82% when the output current of the DCDC converter 300 is 60A.

  By using the above conditions, Pb1 and Pb2 can be derived. By using the derived value, the above condition, and the above equation (1), it is possible to derive ηe when the output current of the DCDC converter 300 is 60 A when the main battery 100 is charged. In this case, η e is approximately 0.352.

  When the output current of the DCDC converter 300 is 60 A (conversion efficiency: 82%), the conversion efficiency of the DCDC converter 300 is lower than that of 50 A (conversion efficiency: 85%). However, ηe is higher when the output current of the DC-DC converter 300 is 60A (ηe: about 0.352) than when it is 50A (ηe: about 0.32). Also from this, it can be understood that even if the DCDC converter 300 is controlled so that the conversion efficiency of the DCDC converter 300 is maximized, the efficiency of the entire power supply system 10 is not necessarily maximized.

[Example of efficiency of entire power supply system (engine off and main battery discharged)]
FIG. 7 is a diagram showing the relationship between power supply system 10, load 135 and accessory 400 when engine 150 is off and main battery 100 is discharged. Referring to FIG. 7, for example, it is assumed that the input voltage of DCDC converter 300 is 200 V, the output voltage is 10 V, and Pload1 is 20000 W (the input power to load 135 is 20000 W). In this case, the current (Iload1) of the load 135 is 100 A (the input current to the load 135 is 100 A). Let Pload2 be 200 W, and the current (Iload2) of the accessory 400 be 20 A. The internal resistance of main battery 100 is 0.1Ω, and the internal resistance of auxiliary battery 200 is 0.01Ω.

  At the time of discharge of the main battery 100, when the output current of the DC-DC converter 300 increases, since Iload1 is fixed, the output current of the main battery 100 increases. Therefore, the power consumption in the internal resistance of main battery 100 is increased. On the other hand, the output current from auxiliary battery 200 to auxiliary device 400 and the input current to auxiliary battery 200 change in the same manner as charging of main battery 100.

  FIG. 8 is a diagram showing the relationship between the conversion efficiency of the DCDC converter 300, Pb1loss, and Pb2loss (when the main battery 100 is discharged) when the output current of the DCDC converter 300 is 50A. Referring to FIG. 8, a diagram showing a relationship between an output current of DCDC converter 300 and a conversion efficiency of DCDC converter 300, a diagram showing a relationship between an output current of DCDC converter 300 and Pb1loss, and a DCDC converter 300 It is a figure which shows the relationship between output current and Pb2loss. The horizontal and vertical axes of each drawing are the same as in FIG. Similar to FIG. 5, when the output current of the DCDC converter 300 is 50 A, the conversion efficiency of the DCDC converter 300 is 85%. If ηe is calculated in the same manner as when the main battery 100 is charged, ηe will be approximately 0.298.

  FIG. 9 is a diagram showing the relationship between the conversion efficiency of the DCDC converter 300, Pb1loss, and Pb2loss (when the main battery 100 is discharged) when the output current of the DCDC converter 300 is 60A. Referring to FIG. 9, a diagram showing the relationship between the output current of DCDC converter 300 and the conversion efficiency of DCDC converter 300, a diagram showing the relationship between the output current of DCDC converter 300 and Pb1loss, and DCDC converter 300 It is a figure which shows the relationship between output current and Pb2loss. The horizontal and vertical axes of each drawing are the same as in FIG. Similar to FIG. 6, when the output current of the DCDC converter 300 is 60 A, the conversion efficiency of the DCDC converter 300 is 82%.

  Pb1 and Pb2 can be derived by using the various conditions described above. By using the derived value, the above-mentioned various conditions, and the above-mentioned equation (1), ηe in the case where the output current of the DCDC converter 300 is 60 A when the main battery 100 is discharged can be derived. In this case, η e is approximately 0.323.

  Comparing ηe at the time of charging (FIGS. 5 and 6) and discharging (FIGS. 8 and 9) of main battery 100, for example, when the output current of DCDC converter 300 is 50 A, ηe at the time of charging is approximately It is 0.32, and ηe at the time of discharge is about 0.298. Further, when the output current of the DC-DC converter 300 is 60 A, η e at the time of charge is about 0.352, and η e at the time of discharge is about 0.323. As understood from these examples, the energy efficiency of the entire power supply system 10 is reduced when the main battery 100 is discharged as compared to the time of charging. When the DCDC converter 300 is operated at the time of discharge, the output current of the main battery 100 is increased, and the power consumption in the internal resistance of the main battery 100 is increased.

[Example of efficiency of entire power supply system (with engine on and main battery charging)]
FIG. 10 is a diagram showing the relationship among power supply system 10, load 135, accessory 400, and engine 150 when engine 150 is on and when main battery 100 is charged. Referring to FIG. 10, for example, it is assumed that the input voltage of DC-DC converter 300 is 200 V and the output voltage is 10 V. Pload1 is set to -20000 W (the output power from the load 135 is 20000 W), and the current (I load1) of the load 135 is set to -100 A (the output current from the load 135 is 100 A). Let Pload2 be 200 W, and the current (Iload2) of the accessory 400 be 20 A. The internal resistance of main battery 100 is 0.1Ω, and the internal resistance of auxiliary battery 200 is 0.01Ω. The drive power (Pv) at the load 135 is 3500 W, and the loss (Pvloss) at the load 135 is 500 W.

  When the engine 150 is in the on state and the main battery 100 is charged, when the output power of the DCDC converter 300 is increased, the necessary power can be provided by increasing the output power of the engine 150. That is, even when the output power of DCDC converter 300 is increased, the input power of main battery 100 is not decreased (constant).

  In the example shown in FIG. 11 described later (output current of DCDC converter 300: 20 A, conversion efficiency: 80%), for example, the fuel heating value (Qfc) for operating engine 150 is 60000 W, and the output power of engine 150 (Pe) becomes 24000W. In an example shown in FIG. 12 described later (output current of DCDC converter 300: 50 A, conversion efficiency: 85%), for example, Qfc is 60200 W and Pe is 24338 W.

  FIG. 11 is a diagram showing the relationship between the conversion efficiency of the DCDC converter 300, Pb1loss, Pb2loss, and loss in the engine 150 (when the main battery 100 is charged) when the output current of the DCDC converter 300 is 20A. Referring to FIG. 11, a diagram (upper diagram) showing the relationship between the output current of DCDC converter 300 and the conversion efficiency of DCDC converter 300 from above, a diagram showing the relationship between output current of DCDC converter 300 and Pb1loss (middle FIG. 14 shows a diagram (upper middle diagram) showing the relationship between the output current of the DCDC converter 300 and Pb2loss (upper middle diagram) and a diagram (lower diagram) showing a relationship between the output current of the DCDC converter 300 and the loss in the engine 150.

  The horizontal axis and the vertical axis of the upper drawing, the middle upper drawing, and the middle lower drawing are the same as the respective drawings of FIG. The horizontal axis of the lower figure shows the output current of the DCDC converter 300, and the vertical axis shows the energy loss in the engine 150. It is assumed that the conversion efficiency of the DCDC converter 300 is 80% when the output current of the DCDC converter 300 is 20A.

  By using the above conditions, Pb1 and Pb2 can be derived. By using the derived value, the above condition, and the above equation (2), it is possible to derive 場合 e_eng in the case where the output current of the DCDC converter 300 is 20 A when the main battery 100 is charged. In this case, ηe_eng is approximately 0.374.

  FIG. 12 is a diagram showing the relationship between the conversion efficiency of the DCDC converter 300, Pb1loss, Pb2loss, and loss in the engine 150 (when the main battery 100 is charged) when the output current of the DCDC converter 300 is 50A. 12, a diagram showing the relationship between the output current of DCDC converter 300 and the conversion efficiency of DCDC converter 300 from the top, a diagram showing the relationship between the output current of DCDC converter 300 and Pb1 loss, the output of DCDC converter 300 FIG. 16 shows a relation between current and Pb2loss and a relation between output current of DCDC converter 300 and loss in engine 150. The horizontal and vertical axes of each drawing are the same as in FIG.

  Pb1 and Pb2 can be derived by using the various conditions described above. By using the derived value, the above-mentioned various conditions, and the above-mentioned equation (2), ηe_eng in the case where the output current of the DCDC converter 300 is 50 A when the main battery 100 is charged can be derived. In this case, ηe_eng is approximately 0.378.

  From the viewpoint of energy efficiency, when engine 150 is on and main battery 100 is discharged, DCDC converter 300 may be stopped regardless of the value of ee_eng.

[Description of map]
FIG. 13 is a diagram for describing a map used for control of DCDC converter 300 in the first embodiment. Referring to FIG. 13, in memory 500, maps 510 and 520 are stored.

  Map 510 is a map used for control of DCDC converter 300 during operation of engine 150. Map 510 shows the voltage ratio of main battery 100 and auxiliary battery 200, the current of main battery 100 and auxiliary device 400, and auxiliary battery 200 when ηe_eng shown in the above equation (2) is maximized. The relationship with the current is shown.

  The map 520 is a map used for control of the DCDC converter 300 while the engine 150 is stopped. The map 520 shows the voltage ratio of the main battery 100 and the auxiliary battery 200, the current of the main battery 100 and the auxiliary device 400, and the auxiliary battery 200 when ηe shown in the above equation (1) is maximized. The relationship with the current is shown.

  Each of maps 510 and 520 includes a plurality of maps prepared for each voltage ratio (Vb1 / Vb2) of main battery 100 and auxiliary battery 200. Each map associates the current of auxiliary battery 200 when η e _eng or η e is maximum with respect to the combination of the current of main battery 100 and the current of auxiliary device 400.

  During operation of engine 150 in hybrid vehicle 1 according to the first embodiment, ECU 600 causes the current of auxiliary battery 200 to be derived from the outputs of current sensors 110 and 410, the outputs of voltage sensors 120 and 220, and map 510. The DCDC converter 300 is controlled to be the target current. On the other hand, while the engine 150 is stopped, the ECU 600 controls the DCDC converter so that the current of the auxiliary battery 200 becomes the outputs of the current sensors 110 and 410, the outputs of the voltage sensors 120 and 220, and the target current derived from the map 520. Control 300 Thus, in the hybrid vehicle 1, the DCDC converter 300 is controlled such that ηe_eng or ηe is maximized, so the energy efficiency of the entire power supply system 10 is improved. Next, a control processing procedure of the DCDC converter 300 will be described.

[Processing procedure of DCDC converter control]
FIG. 14 is a flowchart for illustrating a control processing procedure of DCDC converter 300 in the first embodiment. Referring to FIG. 14, the process shown in this flowchart is executed by ECU 600 in a predetermined cycle.

  The ECU 600 acquires outputs of various sensors (step S100). Specifically, the ECU 600 acquires the outputs of the current sensors 110 and 410 and the voltage sensors 120 and 220.

  Thereafter, the ECU 600 determines whether the engine 150 is in the on state (in operation) (step S110). If it is determined that engine 150 is on (YES in step S110), ECU 600 sets map 510 (FIG. 13) as a map for deriving the target current of auxiliary battery 200, and the process proceeds to step S100. The target current of auxiliary battery 200 is derived using each of the acquired outputs and map 510 (step S120).

  If it is determined that engine 150 is in the off state (during stop) (NO in step S110), ECU 600 sets map 520 (FIG. 13) as a map for deriving the target current of auxiliary battery 200. The target current of the auxiliary battery 200 is derived using the outputs set in step S100 and the map 520 (step S130).

  Thereafter, ECU 600 determines whether the calculated target current of auxiliary battery 200 is less than 0 (zero) (step S140). That is, ECU 600 determines whether current is input to auxiliary battery 200 or whether current is output from auxiliary battery 200.

  When it is determined that the target current of auxiliary battery 200 is 0 or more (NO in step S140), current is output from auxiliary battery 200, and power is supplied from DCDC converter 300 to auxiliary battery 200. Since it is not necessary to do this, the ECU 600 sets the output voltage of the DCDC converter 300 below the voltage of the auxiliary battery 200 (for example, 12 V) (step S160).

  On the other hand, when it is determined that the target current of auxiliary battery 200 is less than 0 (YES in step S140), ECU 600 controls DCDC converter 300 such that the current of auxiliary battery 200 becomes the target current (step S150). For example, while monitoring the output of current sensor 210, ECU 600 performs feedback control such that the current of auxiliary battery 200 becomes the target current. Thereafter, processing shifts to return.

  As described above, in hybrid vehicle 1 according to the first embodiment, memory 500 has the voltage ratio of main battery 100 to auxiliary battery 200, main battery 100 and auxiliary battery 200 when the efficiency of power supply system 10 is maximized. Maps 510 and 520 indicating the relationship between the current of the aircraft 400 and the current of the auxiliary battery 200 are stored. Then, ECU 600 controls DC-DC converter 300 such that the current of auxiliary battery 200 becomes the output of current sensor 110, 410, the output of voltage sensor 120, 220, and the target current derived from maps 510, 520. Thereby, according to this hybrid vehicle 1, the energy efficiency of the power supply system 10 whole can be improved.

Second Embodiment
In hybrid vehicle 1 according to the first embodiment, maps 510 and 520 indicate voltage ratios of main battery 100 and auxiliary battery 200 when ηe_eng or ηe is maximum, and currents of main battery 100 and auxiliary device 400. The relationship with the current of auxiliary battery 200 is shown. However, the current of the accessory 400 can be roughly estimated depending on whether the engine 150 is operating. Therefore, the map in the second embodiment omits the current of auxiliary device 400, and shows the relationship between the voltage ratio of main battery 100 and auxiliary battery 200, the current of main battery 100, and the current of auxiliary battery 200. Show. Thus, in the second embodiment, the current sensor 410 in the first embodiment may not be provided. Hereinafter, differences from the first embodiment will be mainly described.

[Configuration of hybrid vehicle]
Referring to FIG. 1, hybrid vehicle 1A according to the second embodiment includes a memory 500A and an ECU 600A. In the second embodiment, current sensor 410 can be removed. The other configuration is the same as that of the first embodiment.

  Memory 500A is formed of, for example, a non-volatile memory such as a flash memory. Memory 500A stores a map used when controlling DCDC converter 300. This map shows the relationship between the voltage ratio of main battery 100 and auxiliary battery 200, the current of main battery 100, and the current of auxiliary battery 200 when the efficiency of power supply system 10 is maximized (described later) .

  ECU 600A includes a CPU, a storage device, an input / output buffer, and the like (all not shown), and controls each device in hybrid vehicle 1A. Note that this control is not limited to the processing by software, but may be processed by dedicated hardware (electronic circuit).

[Description of map]
FIG. 15 is a diagram for describing a map used for control of DCDC converter 300 in the second embodiment. Referring to FIG. 15, maps 510A and 520A are stored in memory 500A.

  Map 510A is a map used for control of DCDC converter 300 during operation of engine 150. Map 510A is a relationship between the voltage ratio of main battery 100 and auxiliary battery 200, the current of main battery 100, and the current of auxiliary battery 200 when ηe_eng shown in the above-mentioned equation (2) is maximum. Indicates In the calculation of η e _eng, a value predicted to flow during operation of engine 150 is used as the current of auxiliary device 400.

  The map 520A is a map used for control of the DCDC converter 300 while the engine 150 is stopped. Map 520A is a relationship between the voltage ratio of main battery 100 and auxiliary battery 200, the current of main battery 100, and the current of auxiliary battery 200 when ηe shown in the above-mentioned equation (1) is maximum. Indicates In the calculation of ηe, a value predicted to flow while the engine 150 is stopped is used as the current of the accessory 400.

  Each of maps 510A and 520A is the auxiliary battery when ηe_eng or ηe is maximum for the combination of the current of main battery 100 and the voltage ratio (Vb1 / Vb2) of main battery 100 and auxiliary battery 200. Two hundred currents are associated.

  During the operation of engine 150 in hybrid vehicle 1A according to the second embodiment, ECU 600A sets the current of auxiliary battery 200 to the output of current sensor 110, the output of voltage sensors 120 and 220, and the target current derived from map 510A. The DCDC converter 300 is controlled to be On the other hand, while the engine 150 is stopped, the ECU 600A sets the DCDC converter 300 such that the current of the accessory battery 200 becomes the output of the current sensor 110, the outputs of the voltage sensors 120 and 220, and the target current derived from the map 520A. Control. As described above, in the hybrid vehicle 1A, the DCDC converter 300 is controlled such that _e_eng or 最大 e is maximized, so that the energy efficiency of the entire power supply system 10 is improved. Next, a control processing procedure of the DCDC converter 300 will be described.

[Processing procedure of DCDC converter control]
FIG. 16 is a flowchart for illustrating a control processing procedure of DCDC converter 300 in the second embodiment. Referring to FIG. 16, the process shown in this flowchart is executed by ECU 600A in a predetermined cycle. This flowchart is different from the flowchart of FIG. 14 in the processes of steps S100A, S120A, and S130A. Here, differences from FIG. 14 will be mainly described.

  The ECU 600A acquires the outputs of various sensors (step S100A). Specifically, the ECU 600A acquires the outputs of the current sensor 110 and the voltage sensors 120 and 220.

  Thereafter, ECU 600A determines whether engine 150 is in the on state (during operation) (step S110). When engine 150 is determined to be on (YES in step S110), ECU 600A sets map 510A (FIG. 15) as a map for deriving the target current of auxiliary battery 200, and in step S100A. The target current of auxiliary battery 200 is derived using each of the obtained outputs and map 510A (step S120A).

  On the other hand, when engine 150 is determined to be in the off state (during stop) (NO in step S110), ECU 600A sets map 520A (FIG. 15) as a map for deriving the target current of auxiliary battery 200. The target current of auxiliary battery 200 is derived using the outputs set in step S100A and map 520A (step S130A). The processing of the subsequent steps S140 to S160 is the same as that of FIG.

  As described above, in hybrid vehicle 1A according to the second embodiment, during the operation of engine 150, ECU 600A outputs the current of auxiliary battery 200 as the output of current sensor 110, the output of voltage sensors 120 and 220, and map 510A. The DC-DC converter 300 is controlled to be a target current derived from On the other hand, while the engine 150 is stopped, the ECU 600A sets the DCDC converter 300 such that the current of the accessory battery 200 becomes the output of the current sensor 110, the outputs of the voltage sensors 120 and 220, and the target current derived from the map 520A. Control. Thus, according to this hybrid vehicle 1A, the energy efficiency of the entire power supply system 10 can be improved.

Third Embodiment
In each of hybrid vehicles 1 and 1A according to the first and second embodiments, DCDC converter 300 is controlled to maximize ηe or ee_eng by using various maps. In hybrid vehicle 1B according to the third embodiment, DCDC converter 300 is controlled without using the maps as in the first and second embodiments.

[Configuration of hybrid vehicle]
Referring to FIG. 1, hybrid vehicle 1B according to the third embodiment includes a memory 500B and an ECU 600B. The other configuration is the same as that of the first embodiment.

  Memory 500B is formed of, for example, a non-volatile memory such as a flash memory. Memory 500 B stores a predetermined equation prepared in advance for control of DCDC converter 300. This predetermined equation is based on the voltage ratio of main battery 100 and auxiliary battery 200, the current of main battery 100, and the conversion efficiency of DCDC converter 300 when the power loss of main battery 100 and auxiliary battery 200 is minimized. And the current of auxiliary battery 200 is shown. The predetermined equation will be described in detail later.

  ECU 600B includes a CPU, a storage device, an input / output buffer and the like (all not shown), and controls each device in hybrid vehicle 1B. Note that this control is not limited to the processing by software, but may be processed by dedicated hardware (electronic circuit).

[Improvement of overall efficiency of the power supply system by the method without using maps]
As described above, when the output power of the DCDC converter 300 is increased when the main battery 100 is discharged, the output power of the main battery 100 is increased, and thus the power loss in the internal resistance of the main battery 100 is increased. As a result, the energy efficiency of the entire power supply system 10 is reduced.

  On the other hand, when the output power of DCDC converter 300 is increased when charging main battery 100, the input power of main battery 100 is reduced, and therefore the power loss in the internal resistance of main battery 100 is reduced. Further, as can be seen from the upper diagram of FIG. 5 and the like, when the output current of the DCDC converter 300 is increased to a certain extent during charging of the main battery 100, the conversion efficiency of the DCDC converter 300 does not fluctuate significantly. Therefore, in this case, the power loss in main battery 100 and auxiliary battery 200 greatly affects the energy efficiency of power supply system 10 as a whole.

  Therefore, in hybrid vehicle 1B according to the third embodiment, control is performed to stop DCDC converter 300 when main battery 100 is discharged. On the other hand, when charging main battery 100, DCDC converter 300 is controlled such that power loss in main battery 100 and auxiliary battery 200 is minimized. In order to minimize power loss in main battery 100 and auxiliary battery 200, the following predetermined equation is used. Thus, according to this hybrid vehicle 1B, the energy efficiency of the entire power supply system 10 can be improved.

[Predetermined formula]
The above-mentioned predetermined formula is shown by the following formulas (3) and (4).

Ib2 = (2.B.R.Ib1 (+ B.vact)) / (2r + 2B ² R) (3)
B = vb 2 / (η · vb 1) · · · (4)
Here, R is the internal resistance of main battery 100, r is the internal resistance of auxiliary battery 200, vact is the polarization voltage, vb1 is the voltage of main battery 100, and vb2 is the speed of auxiliary battery 200. Is a voltage, and η is the conversion efficiency of the DC-DC converter 300.

  Power loss in main battery 100 and auxiliary battery 200 can be minimized by setting the current of auxiliary battery 200 to the value represented by equation (3). As a result, according to the hybrid vehicle 1B, the energy efficiency of the entire power supply system 10 can be improved when the main battery 100 is charged, without holding a huge amount of maps. Next, a control processing procedure of the DCDC converter 300 will be described.

[Processing procedure of DCDC converter control]
FIG. 17 is a flowchart for illustrating a control processing procedure of DCDC converter 300 in the third embodiment. Referring to FIG. 17, the process shown in this flowchart is executed by ECU 600B in a predetermined cycle.

  The ECU 600B acquires the outputs of various sensors (step S200). Thereafter, ECU 600B determines whether or not the current of main battery 100 is less than 0 (zero) (whether or not in a charged state) (step S210).

  If it is determined that the current of main battery 100 is 0 or more (discharged state) (NO in step S210), ECU 600B sets the output voltage of DCDC converter 300 to the voltage of auxiliary battery 200 or less (for example, 12 V). (Step S220). That is, the DCDC converter 300 is stopped.

  On the other hand, when it is determined that the current of main battery 100 is less than 0 (the state of charge) (YES in step S210), ECU 600B uses the predetermined equations (equations (3), (4)) to The target current of the battery 200 is derived (step S230). Thereafter, ECU 600B controls DCDC converter 300 such that the current of auxiliary battery 200 becomes the target current (step S240). Thereafter, processing shifts to return.

  As described above, in hybrid vehicle 1B according to the third embodiment, control is performed to stop DCDC converter 300 when main battery 100 is discharged. Then, when charging main battery 100, DCDC converter 300 is controlled using a predetermined equation so that the power loss in main battery 100 and auxiliary battery 200 is minimized. Thereby, according to this hybrid vehicle 1B, the energy efficiency of the entire power supply system 10 can be improved without maintaining a huge amount of maps.

(Other embodiments)
As described above, Embodiments 1 to 3 have been described as the embodiments of the present invention. However, the present invention is not necessarily limited to the first to third embodiments. Here, an example of another embodiment will be described.

  In the second embodiment, the map used to control DCDC converter 300 is changed depending on whether or not engine 150 is operating. However, the requirement to change the map is not only whether the engine 150 is operating. For example, the map may be changed by determining whether the air conditioner is in use as well as whether the engine 150 is in operation. In this case, the map M1 when the engine 150 is on and the air conditioner is on, the map M2 when the engine 150 is on and the air conditioner is off, and the engine 150 is off In addition, the map M3 when the air conditioner is on and the map M4 when the engine 150 is off and the air conditioner is off are held in the hybrid vehicle. This makes it possible to more accurately predict the current flowing to auxiliary device 400 for each situation, so that the energy efficiency of the entire power supply system 10 can be further improved.

  In the third embodiment, DCDC converter 300 is controlled such that the power loss in main battery 100 and auxiliary battery 200 is minimized when main battery 100 is charged. However, such control need not always be performed when the main battery 100 is charged. For example, even when the main battery 100 is charged, the target current of the auxiliary battery 200 may be increased to the upper limit of acceptance of the auxiliary battery 200 when the engine 150 is in the on state.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all the modifications within the meaning and scope equivalent to the claims.

  1,1A, 1B hybrid vehicle, 10 power system, 100 main battery, 110, 210, 410 current sensor, 120, 220 voltage sensor, 125, 225 power line pair, 130 PCU, 135 load, 140, 145 motor generator, 150 engine , 155 power split device, 160 transmission gear, 170 drive wheel, 200 auxiliary battery, 300 DC DC converter, 400 auxiliary machine, 500, 500A, 500B memory, 510, 510A, 520, 520A map, 600, 600A, 600B ECU.

Claims (3)

A motor that generates a traveling drive force of the vehicle;
A main battery for storing power supplied to the motor;
Auxiliary machine,
An auxiliary battery for storing power supplied to the auxiliary device;
A converter connected between the main battery and the auxiliary battery;
A first current sensor for detecting a first current indicative of the current of the main battery;
A second current sensor for detecting a second current indicative of the current of the accessory;
A first voltage sensor that detects a first voltage indicating a voltage of the main battery;
A second voltage sensor for detecting a second voltage indicative of the voltage of the auxiliary battery;
The ratio of the first and second voltages, the first and second currents, and the accessory when the efficiency of the power supply system including the main battery, the accessory battery, and the converter is maximized. A memory that stores a map that shows the relationship with battery current;
A control device for controlling the converter such that the current of the auxiliary battery is a value obtained from the outputs of the first and second current sensors, the outputs of the first and second voltage sensors, and the map And a vehicle. With the engine,
A motor that generates a traveling drive force of the vehicle;
A main battery for storing power supplied to the motor;
Auxiliary machine,
An auxiliary battery for storing power supplied to the auxiliary device;
A converter connected between the main battery and the auxiliary battery;
A current sensor for detecting the current of the main battery;
A first voltage sensor that detects a first voltage indicating a voltage of the main battery;
A second voltage sensor for detecting a second voltage indicative of the voltage of the auxiliary battery;
A memory for storing the first and second maps;
A controller for controlling the converter;
The first map is a ratio of the first and second voltages when the efficiency of a power supply system including the main battery, the accessory battery, and the converter is maximized during operation of the engine; Showing a relationship between the current of the main battery and the current of the auxiliary battery,
The second map shows the ratio of the first and second voltages, the current of the main battery, and the current of the auxiliary battery when the efficiency of the power supply system is maximized while the engine is stopped. Show the relationship with
The controller is
During operation of the engine, the converter is configured such that the current of the auxiliary battery is a value determined from the output of the current sensor, the outputs of the first and second voltage sensors, and the first map. While controlling
During the stop of the engine, the converter is controlled so that the current of the auxiliary battery becomes the value determined from the output of the current sensor, the outputs of the first and second voltage sensors, and the second map. Control the vehicle. A motor that generates a traveling drive force of the vehicle;
A main battery for storing power supplied to the motor;
Auxiliary machine,
An auxiliary battery for storing power supplied to the auxiliary device;
A converter connected between the main battery and the auxiliary battery;
A current sensor for detecting the current of the main battery;
A first voltage sensor that detects a first voltage indicating a voltage of the main battery;
A second voltage sensor for detecting a second voltage indicative of the voltage of the auxiliary battery;
A controller for controlling the converter;
The controller is
When the main battery is discharged, the converter is stopped,
At the time of charging of the main battery, the converter is controlled such that the current of the auxiliary battery has a value obtained from a predetermined equation prepared in advance;
The predetermined equation includes the ratio of the first and second voltages, the current of the main battery, and the conversion efficiency of the converter when the power loss of the main battery and the auxiliary battery is minimized. A vehicle showing a relationship with the current of the auxiliary battery.

Images