JP2014023374A - Power unit and vehicle including the same and control method of power unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power unit having a plurality of power storage devices in which loss can be suppressed, and to provide a vehicle including the same.SOLUTION: The power unit includes a power storage device B1, a power storage device B2, a power adjustment section 80, and an ECU 30. The power storage device B1 supplies power to a load. The power storage device B2 is provided in parallel with the power storage device B1, and supplies power to a load. The power adjustment section 80 is provided between the power storage device B1 and the load, and adjusts I/O power of the power storage device B1. The ECU 30 controls the power adjustment section 80 based on the power required for the load, the internal resistance loss of the power storage device B1, and the internal resistance loss of the power storage device B2.

Description

  The present invention relates to a power supply device, and more particularly to a power supply device having a plurality of power storage devices.

  Japanese Patent Laying-Open No. 2011-199934 (Patent Document 1) discloses a power supply device having a plurality of power storage devices. In this power supply device, normally, only the power from the first power storage device is supplied to the load. When power that is higher than the power that can be supplied by the first power storage device is requested, the power that is insufficient is compensated by the power from the second power storage device (see Patent Document 1).

JP 2011-199934 A JP 2009-213299 A JP 2003-209969 A

  However, in the power supply device as described above, it is merely disclosed that the output of the second power storage device is supplemented with power that is insufficient only by the output of the first power storage device, and a method for suppressing the loss of the power supply device as a whole. No particular consideration has been given to.

  Therefore, an object of the present invention is to provide a power supply device capable of suppressing loss in a power supply device having a plurality of power storage devices and a vehicle including the same.

  Another object of the present invention is to provide a control method of a power supply device that can suppress loss in a power supply device having a plurality of power storage devices.

  According to the present invention, the power supply device includes the first power storage device, the second power storage device, the power adjustment unit, and the control device. The first power storage device supplies power to the load. The second power storage device is provided in parallel with the first power storage device and supplies power to the load. The power adjustment unit is provided between the first power storage device and the load, and adjusts input / output power of the first power storage device. The control device controls the power adjustment unit based on the required power for the load, the internal resistance loss of the first power storage device, and the internal resistance loss of the second power storage device.

  Preferably, the control device determines the input / output power of the first power storage device and the first power based on the required power, the voltage value and the internal resistance value of the first power storage device, and the voltage value and the internal resistance value of the second power storage device. (2) The power adjustment unit is controlled so as to adjust the input / output power of the power storage device.

  Preferably, the control device sets the input / output power of the first power storage device and the input / output power of the second power storage device in a direction in which the total of the internal resistance loss of the first power storage device and the internal resistance loss of the second power storage device decreases. Adjust the power ratio.

  Preferably, the control device sets the power adjustment unit to adjust the remaining capacity ratio between the remaining capacity of the first power storage device and the remaining capacity of the second power storage device to a predetermined ratio when the required power is smaller than a predetermined value. Control.

  Preferably, the control device calculates in advance a power transfer loss that occurs when the remaining capacity ratio is adjusted to a predetermined ratio. The control device controls the power adjustment unit based on the power transfer loss.

  Preferably, the power adjustment unit includes a booster circuit configured to boost the voltage of the first power storage device and supply the boosted voltage to the load.

  Preferably, the power adjustment unit further includes a rectifying element that is provided between the output of the booster circuit and the second power storage device and regulates a current flow to the second power storage device.

  Preferably, the power adjustment unit further includes a switching element provided in parallel with the rectifying element.

According to the invention, the vehicle includes any one of the power supply devices described above.
According to the invention, the method for controlling the power supply device is a method for controlling the power supply device including the first power storage device, the second power storage device, the power adjustment unit, and the control device. The first power storage device supplies power to the load. The second power storage device is provided in parallel with the first power storage device and supplies power to the load. The power adjustment unit is provided between the first power storage device and the load, and adjusts input / output power of the first power storage device. The control method includes the steps of obtaining required power for the load, internal resistance loss of the first power storage device, and internal resistance loss of the second power storage device, required power, internal resistance loss of the first power storage device, 2 controlling the power adjustment unit based on the internal resistance loss of the power storage device.

  Preferably, the controlling step includes: input / output power of the first power storage device based on the required power, the voltage value and the internal resistance value of the first power storage device, and the voltage value and the internal resistance value of the second power storage device; The step of controlling the power adjustment unit to adjust the input / output power of the second power storage device is included.

  Preferably, the controlling step is such that the total of the internal resistance loss of the first power storage device and the internal resistance loss of the second power storage device decreases, so that the input / output power of the first power storage device and the input / output power of the second power storage device The method further includes a step of adjusting a power ratio between the first and second powers.

  Preferably, the controlling step includes a power adjustment unit configured to adjust a remaining capacity ratio between the remaining capacity of the first power storage device and the remaining capacity of the second power storage device to a predetermined ratio when the required power is smaller than a predetermined value. The step of controlling is included.

  Preferably, the step of controlling further includes a step of calculating in advance a power movement loss that occurs when the remaining capacity ratio is adjusted to a predetermined ratio, and a step of controlling the power adjustment unit based on the power movement loss.

  In the present invention, the power adjustment unit is controlled based on the required power, the internal resistance loss of the first power storage device, and the internal resistance loss of the second power storage device. Thereby, it is possible to adjust the outputs of the first power storage device and the second power storage device in consideration of the loss generated in the first power storage device and the second power storage device. Therefore, according to the present invention, loss can be suppressed in a power supply device having a plurality of power storage devices.

1 is an overall block diagram of a hybrid vehicle equipped with a power supply device according to Embodiment 1 of the present invention. It is a circuit diagram which shows the structure of the converter shown in FIG. It is a functional block diagram of ECU shown in FIG. It is a detailed functional block diagram of the converter control part shown in FIG. It is the figure which showed the relationship between the output ratio of a 1st electrical storage apparatus, and the loss of the 1st electrical storage apparatus and the whole 2nd electrical storage apparatus. It is a flowchart which shows the flow of a process by the converter control part shown in FIG. It is a flowchart which shows the flow of a process by the converter control part by the modification of Embodiment 1 of this invention. It is a flowchart which shows the flow of a process by the converter control part by another modification of Embodiment 1 of this invention. It is a whole block diagram of the hybrid vehicle carrying the power supply device by Embodiment 2 of this invention. It is a whole block diagram of the hybrid vehicle carrying the power supply device by Embodiment 3 of this invention.

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

[Embodiment 1]
1 is an overall block diagram of a hybrid vehicle equipped with a power supply device according to Embodiment 1 of the present invention. Referring to FIG. 1, hybrid vehicle 100 includes an engine 2, motor generators MG <b> 1 and MG <b> 2, a power split device 4, and wheels 6. Hybrid vehicle 100 further includes power storage devices B1 and B2, a power adjustment unit 80, a capacitor C, inverters 20 and 22, and an ECU (Electronic Control Unit) 30. In addition, hybrid vehicle 100 further includes voltage sensors 42, 44, 46 and current sensors 52, 54.

  This hybrid vehicle 100 travels using engine 2 and motor generator MG2 as power sources. Power split device 4 is coupled to engine 2 and motor generators MG1 and MG2 to distribute power between them. Power split device 4 includes, for example, a planetary gear mechanism having three rotation shafts of a sun gear, a planetary carrier, and a ring gear, and these three rotation shafts are connected to the rotation shafts of engine 2 and motor generators MG1, MG2, respectively. It should be noted that engine 2 and motor generators MG1, MG2 can be mechanically connected to power split device 4 by hollowing the rotor of motor generator MG1 and passing the crankshaft of engine 2 through the center thereof. Further, the rotation shaft of motor generator MG2 is coupled to wheel 6 by a reduction gear or a differential gear (not shown).

  Motor generator MG1 operates as a generator driven by engine 2 and is incorporated in hybrid vehicle 100 as an electric motor that can start engine 2, and motor generator MG2 drives wheels 6. As an electric motor, the hybrid vehicle 100 is incorporated.

  Power storage devices B1, B2 are chargeable / dischargeable DC power supplies, and include, for example, secondary batteries such as nickel metal hydride and lithium ions. The power storage devices B1 and B2 supply power to the inverters 20 and 22 that are loads, and are charged by the power from the inverters 20 and 22 during power regeneration.

  For example, a secondary battery having a maximum outputable power larger than that of power storage device B2 can be used for power storage device B1, and a secondary battery having a larger storage capacity than power storage device B1 can be used for power storage device B2. be able to. Thus, a high-power and large-capacity DC power source can be configured using the two power storage devices B1 and B2. Note that a configuration in which a secondary battery having a larger storage capacity than the power storage device B2 is used as the power storage device B1 and a secondary battery having a maximum output power higher than that of the power storage device B1 may be used as the power storage device B2. . Further, the power storage devices B1 and B2 may be a combination of different types of secondary batteries, and a large-capacity capacitor may be used for at least one of the power storage devices B1 and B2.

  Power adjustment unit 80 is provided between power storage device B <b> 1 and inverters 20 and 22, and includes converter 10. Power adjustment unit 80 supplies power received from power storage devices B1 and B2 to inverters 20 and 22. In addition, power adjustment unit 80 supplies power received from inverters 20 and 22 to power storage devices B1 and B2. At this time, power adjustment unit 80 can adjust the input / output power of power storage device B1 and the input / output power of power storage device B2 by adjusting the operation of converter 10. Furthermore, the power adjustment unit 80 can adjust the power that moves between the power storage device B1 and the power storage device B2.

  Converter 10 boosts the voltage from power storage device B1 based on signal PWC1 from ECU 30, and outputs the boosted voltage to positive line PL3. Power storage device B2 is connected to positive electrode line PL3 through positive electrode line PL2. Converter 10 steps down the regenerative power supplied from inverters 20 and 22 via positive line PL3 to the voltage level of power storage device B1 based on signal PWC1, and charges power storage device B1.

  Capacitor C is connected between positive electrode line PL3 and negative electrode line NL, and smoothes voltage fluctuations between positive electrode line PL3 and negative electrode line NL.

  Inverter 20 converts a DC voltage from positive line PL3 into a three-phase AC voltage based on signal PWI1 from ECU 30, and outputs the converted three-phase AC voltage to motor generator MG1. Inverter 20 converts the three-phase AC voltage generated by motor generator MG1 using the power of engine 2 into a DC voltage based on signal PWI1, and outputs the converted DC voltage to positive line PL3.

  Inverter 22 converts a DC voltage from positive line PL3 into a three-phase AC voltage based on signal PWI2 from ECU 30, and outputs the converted three-phase AC voltage to motor generator MG2. Further, inverter 22 converts the three-phase AC voltage generated by motor generator MG2 by receiving the rotational force from wheel 6 during regenerative braking of the vehicle into a DC voltage based on signal PWI2, and the converted DC voltage is positive. Output to line PL3.

  Each of motor generators MG1 and MG2 is a three-phase AC rotating electric machine, and includes, for example, a three-phase AC synchronous motor generator. Motor generator MG1 is regeneratively driven by inverter 20, and outputs a three-phase AC voltage generated using the power of engine 2 to inverter 20. Motor generator MG1 is driven by power by inverter 20 when engine 2 is started, and cranks engine 2. Motor generator MG <b> 2 is driven by power by inverter 22, and generates a driving force for driving wheels 6. Motor generator MG <b> 2 is regeneratively driven by inverter 22 during regenerative braking of the vehicle, and outputs a three-phase AC voltage generated using the rotational force received from wheels 6 to inverter 22.

  Voltage sensor 42 detects voltage VB1 of power storage device B1 and outputs it to ECU 30. Current sensor 52 detects current I1 output from power storage device B1 to converter 10 and outputs the detected current to ECU 30. Voltage sensor 44 detects voltage VB2 of power storage device B2 and outputs it to ECU 30. Current sensor 54 detects current I2 output from power storage device B2 and outputs the detected current to ECU 30. Voltage sensor 46 detects a voltage between terminals of capacitor C, that is, voltage VH of positive line PL3 with respect to negative line NL, and outputs the detected voltage VH to ECU 30.

  ECU 30 calculates an internal resistance value R1 of power storage device B1 based on voltage VB1 and current I1. ECU 30 calculates an internal resistance value R2 of power storage device B2 based on voltage VB2 and current I2.

  ECU 30 determines power required for power storage devices B1 and B2 (hereinafter simply referred to as “required power”) PR, voltage VB1, internal resistance value R1, voltage VB2, and internal resistance value R2. Based on this, signal PWC1 for driving converter 10 is generated, and generated signal PWC1 is output to converter 10. The required power PR is calculated by a vehicle ECU (not shown) based on the accelerator pedal opening, the vehicle speed, and the like.

  Further, ECU 30 generates signals PWI1 and PWI2 for driving inverters 20 and 22, respectively, and outputs the generated signals PWI1 and PWI2 to inverters 20 and 22, respectively.

  FIG. 2 is a circuit diagram showing a configuration of converter 10 shown in FIG. Referring to FIG. 2, converter 10 includes npn transistors Q 1 and Q 2, diodes D 1 and D 2, and a reactor L. Npn transistors Q1 and Q2 are connected in series between positive electrode line PL3 and negative electrode line NL. Diodes D1 and D2 are connected in antiparallel to npn transistors Q1 and Q2, respectively. Reactor L has one end connected to a connection node of npn transistors Q1 and Q2, and the other end connected to positive electrode line PL1. As the above npn transistor, for example, an IGBT (Insulated Gate Bipolar Transistor) can be used.

  This converter 10 includes a chopper circuit. Converter 10 boosts the voltage of positive line PL1 using reactor L based on signal PWC1 from ECU 30 (not shown), and outputs the boosted voltage to positive line PL3.

  Specifically, converter 10 accumulates current that flows when npn transistor Q2 is turned on in reactor L as magnetic field energy. Converter 10 boosts the voltage of positive line PL1 by outputting the magnetic field energy to positive line PL3 via diode D1 in synchronization with the timing when npn transistor Q2 is turned off.

  FIG. 3 is a functional block diagram of ECU 30 shown in FIG. Referring to FIG. 3, ECU 30 includes a converter control unit 32 and inverter control units 34 and 36.

  Converter control unit 32 performs PWM (Pulse Width) for turning on / off npn transistors Q1 and Q2 of converter 10 based on required power PR, voltage VB1, current I1, voltage VB2, and current I2. Modulation) signal is generated, and the generated PWM signal is output to the converter 10 as the signal PWC1.

  Based on torque command TR1 of motor generator MG1, motor current MCRT1, rotor rotation angle θ1, and voltage VH, inverter control unit 34 generates a PWM signal for turning on / off a power transistor included in inverter 20, The generated PWM signal is output to inverter 20 as signal PWI1.

  Based on torque command TR2 of motor generator MG2, motor current MCRT2, rotor rotation angle θ2, and voltage VH, inverter control unit 36 generates a PWM signal for turning on / off the power transistor included in inverter 22, The generated PWM signal is output to inverter 22 as signal PWI2.

  The torque commands TR1 and TR2 are calculated by a vehicle ECU (not shown) based on, for example, the accelerator opening, the brake depression amount, the vehicle speed, and the like. Motor currents MCRT1 and MCRT2 and rotor rotation angles θ1 and θ2 are detected by sensors (not shown).

  FIG. 4 is a detailed functional block diagram of converter control unit 32 shown in FIG. Referring to FIG. 4, converter control unit 32 includes a target power ratio calculation unit 102 and a drive signal generation unit 104.

  Target power ratio calculation unit 102 calculates an internal resistance value R1 of power storage device B1 based on voltage VB1 and current I1, and calculates an internal resistance value R2 of power storage device B2 based on voltage VB2 and current I2. Is calculated. The target power ratio calculation unit 102 inputs / outputs the power storage device B1 and the input / output of the power storage device B2 based on the required power PR, the voltage VB1, the internal resistance value R1, the voltage VB2, and the internal resistance value R2. A target power ratio indicating a power ratio is calculated. The target power ratio calculation unit 102 outputs the calculated target power ratio to the drive signal generation unit 104.

  Drive signal generation unit 104 generates signal PWC 1 based on the target power ratio received from target power ratio calculation unit 102 and outputs the signal PWC 1 to converter 10. Specifically, drive signal generation unit 104 calculates the target input / output power of power storage device B1 and the target input / output power of power storage device B2 from the required power PR and the target power ratio. Drive signal generation unit 104 calculates actual input / output power PB1 of power storage device B1 based on voltage VB1 and current I1, and actual input of power storage device B2 based on voltage VB2 and current I2. The output power PB2 is calculated. The drive signal generation unit 104 calculates the duty ratio of the npn transistors Q1 and Q2 so that the input / output power PB1 and PB2 become the target input / output power, and generates the signal PWC1. Drive signal generation unit 104 outputs generated signal PWC1 to converter 10.

  Here, the target power ratio calculation unit 102 determines the target power ratio between the input / output power of the power storage device B1 and the input / output power of the power storage device B2 from the viewpoint of suppressing the loss of the entire power storage devices B1 and B2. Hereinafter, this concept will be described.

  FIG. 5 is a diagram showing the relationship between the output ratio of power storage device B1 and the loss of power storage device B1 and power storage device B2 as a whole. The output ratio of the power storage device B1 is the ratio of the output of the power storage device B1 to the total output of the power storage device B1 and the output of the power storage device B2.

  In the power storage device, internal resistance loss due to internal resistance occurs when current is input and output. This internal resistance loss is calculated by multiplying the internal resistance value and the square of the current. As shown in FIG. 5, when the required power PR is constant, the total loss that is the sum of the internal resistance loss of power storage device B1 and the internal resistance loss of power storage device B2 is accompanied by a change in the output ratio of power storage device B1. Changes. The equal required power line LN1 indicates the total loss when the required power PR is larger than the equal required power line LN2, and the equal required power line LN3 is the entire when the required power PR is smaller than the equal required power line LN2. Indicates loss.

  In the conventional power supply device, when the required power PR is larger than the output power of the power storage device B2, control is performed so that the insufficient power is supplemented by the output power from the power storage device B1. Thus, since the power ratio is determined regardless of the loss, the output ratio K1 of the power storage device B1 may be selected. In this case, the charging / discharging efficiency of a power supply device falls by generating the whole loss L1.

  On the other hand, in the present invention, the output ratio K2 that minimizes the overall loss is selected. In this case, an overall loss L2 lower than the overall loss L1 occurs. For this reason, the charging / discharging efficiency of a power supply device improves because the whole loss falls.

  Here, an example of a method for calculating the power ratio that minimizes the overall loss will be described. Required power PR is the sum of output P1 of power storage device B1 and output P2 of power storage device B2.

PR = P1 + P2 (1)
In power storage device B1, output P1 is expressed by the following equation using voltage VB1, current I1, and internal resistance value R1.

P1 = (VB1-R1 × I1) I1 (2)
Similarly, in power storage device B2, output P2 is expressed by the following equation using voltage VB2, current I2, and internal resistance value R2.

P2 = (VB2-R2 × I2) I2 (3)
The total loss Loss is the sum of the loss of the power storage device B1 and the loss of the power storage device B2, and is expressed by the following equation.

Loss = R1 × I1 ² + R2 × I2 ² (4)
When dLoss / dP1 becomes zero, the total loss Loss is minimized.

dLoss / dP1 = 0 (5)
From the formulas (1) to (5), the power ratio that minimizes the overall loss Loss is expressed by the following formula.

P1 / PR = R2 × VB1 ² / (R2 × VB1 ² + R1 × VB2 ² ) (6)
In this way, the power ratio that minimizes the overall loss Loss can be calculated based on the internal resistance value R1 and voltage VB1 of the power storage device B1 and the internal resistance value R2 and voltage VB2 of the power storage device B2.

  Although the power ratio is calculated in consideration of the internal resistance loss of power storage devices B1 and B2 as the loss, the power ratio may be calculated in consideration of the loss in power adjustment unit 80 and the like. The loss in the power adjustment unit 80 is, for example, a loss in the converter 10.

  FIG. 6 is a flowchart showing a flow of processing by converter control unit 32 shown in FIG. Note that the processing of this flowchart is called from the main routine and executed at regular time intervals or whenever a predetermined condition is satisfied.

  Referring to FIG. 6, converter control unit 32 detects the state quantities of power storage device B1 and power storage device B2 (step S100). Specifically, converter control unit 32 detects voltage VB1 and current I1, and calculates internal resistance value R1 based on these. Converter control unit 32 detects voltage VB2 and current I2, and calculates internal resistance value R2 based on these.

  Subsequently, in step S200, converter control unit 32 determines power ratio X that minimizes the sum of the internal resistance loss of power storage device B1 and the internal resistance loss of power storage device B2 as the target power ratio. Converter control unit 32 calculates P1 / PR as power ratio X based on internal resistance values R1, R2 and voltages VB1, VB2 from the above equation (6).

  Subsequently, in step S300, converter control unit 32 calculates target input / output power of power storage devices B1 and B2 based on required power PR and target power ratio, and actual input / output power becomes target input / output power. Thus, the signal PWC1 is generated and output to the converter 10.

  In addition, power adjustment unit 80 can adjust the power transfer between power storage device B1 and power storage device B2 by the boosting operation of converter 10. When converter 10 makes voltage VH higher than voltage VB2, power storage device B2 is charged. On the other hand, when converter 10 makes voltage VH lower than voltage VB2, power storage device B2 is discharged. Thus, converter 10 can adjust voltage VH to adjust power transfer between power storage device B1 and power storage device B2.

  As described above, in Embodiment 1, power adjustment unit 80 is controlled based on required power PR, internal resistance loss of power storage device B1, and internal resistance loss of power storage device B2. Thereby, the output of power storage devices B1 and B2 can be adjusted in consideration of the loss generated in power storage devices B1 and B2. Therefore, according to the first embodiment, loss can be suppressed in the power supply device having a plurality of power storage devices.

  Further, in the first embodiment, power adjustment unit 80 is based on required power PR, voltage VB1 and internal resistance value R1 of power storage device B1, and voltage VB2 and internal resistance value R2 of power storage device B2. Control is performed to adjust the input / output power of power storage device B1 and the input / output power of power storage device B2. Therefore, loss can be suppressed by adjusting the input / output power of power storage device B1 and the input / output power of power storage device B2.

  In the first embodiment, the power ratio between the input / output power of power storage device B1 and the input / output power of power storage device B2 is reduced by the sum of the internal resistance loss of power storage device B1 and the internal resistance loss of power storage device B2. You may adjust to the direction to do. Therefore, loss can be suppressed by adjusting the power ratio between the input / output power of power storage device B1 and the input / output power of power storage device B2.

  In the first embodiment, converter 10 is configured to be capable of boosting voltage VB1 of power storage device B1. Therefore, by controlling the boosting operation of converter 10, the input / output power of power storage devices B1 and B2 can be adjusted.

[Modification of Embodiment 1]
In Embodiment 1, power is output at a power ratio that minimizes the internal resistance loss of the power storage device regardless of the remaining capacity of the power storage device. For this reason, when there is a bias between the remaining capacity of the power storage device B1 and the remaining capacity of the power storage device B2, the capacity of one power storage device will reach the lower limit first, so the power ratio is maintained and both The remaining capacity of the power storage device may not be used up. Therefore, in the modification of the first embodiment, when the required power PR is small, the power is moved between the power storage device B1 and the power storage device B2, thereby maintaining the power ratio and reducing the remaining capacity of both power storage devices. Can be used up.

  FIG. 7 is a flowchart showing a flow of processing by converter control unit 32 according to a modification of the first embodiment of the present invention. Note that the processing of this flowchart is called from the main routine and executed at regular time intervals or whenever a predetermined condition is satisfied.

  Referring to FIG. 7, steps S100, S200, and S300 are the same as those in the first embodiment, and thus description thereof will not be repeated.

  In step S110, converter control unit 32 determines whether or not required power PR is smaller than a predetermined value Pth. The predetermined value Pth is a value at which the internal resistance loss of the power storage device B1 and the power storage device B2 becomes significant. If a positive determination is made in this process (YES in step S110), the process proceeds to step S120. On the other hand, if a negative determination is made in step S110 (NO in step S110), the process proceeds to step S200.

  In step S120, converter control unit 32 determines whether there is a bias between the remaining capacity of power storage device B1 and the remaining capacity of power storage device B2. For example, converter control unit 32 determines that there is a bias when the ratio between the remaining capacity of power storage device B1 and the remaining capacity of power storage device B2 is different from power ratio X. The remaining capacity is represented by the electric energy [Wh] and is calculated using various known methods. If a positive determination is made in this process (YES in step S120), the process proceeds to step S130. On the other hand, if a negative determination is made in step S120 (NO in step S120), the process proceeds to step S200.

  In step S130, converter control unit 32 calculates the amount of power transfer between power storage device B1 and power storage device B2. This power transfer amount is the amount of power that moves per unit time calculated based on the loss caused by the power transfer, the remaining capacity of power storage device B1 and power storage device B2, and can be an arbitrary value, for example. .

  Subsequently, in step S140, converter control unit 32 determines power ratio Y accompanied by power transfer as a target power ratio. The power ratio Y is calculated based on the required power PR and the amount of power transfer calculated in step S130. By adjusting the power ratio to the power ratio Y, the total of the required power PR and the amount of power transfer is output from one power storage device, and the other power storage device is charged with power for the amount of power transfer.

  As described above, in the modification of the first embodiment, when the required power PR is small, power is moved between power storage device B1 and power storage device B2. Therefore, it is possible to use up the remaining capacity of both power storage devices while maintaining the power ratio that minimizes the internal resistance loss of power storage device B1 and power storage device B2.

[Another Modification of First Embodiment]
In the modification of the first embodiment, when the required power PR is small, the power is moved between the power storage device B1 and the power storage device B2, thereby maintaining the power ratio that minimizes the internal resistance loss of the power storage device. The remaining capacity of the power storage device can be used up. However, when the movement loss caused by moving the electric power between power storage device B1 and power storage device B2 is large, the efficiency of the power supply device may be reduced. Therefore, in another modification of the first embodiment, the power ratio is determined in consideration of the movement loss, and the deterioration of efficiency due to the power movement is suppressed.

  FIG. 8 is a flowchart showing a flow of processing by converter control unit 32 according to another modification of the first embodiment of the present invention. Note that the processing of this flowchart is called from the main routine and executed at regular time intervals or whenever a predetermined condition is satisfied.

  Referring to FIG. 8, steps S100 and S110 to S300 are the same as those in the first embodiment and the modifications thereof, and therefore description thereof will not be repeated.

  In step S102, converter control unit 32 calculates loss A at the power ratio at which the internal resistance loss of power storage device B1 and power storage device B2 is minimized.

  Subsequently, in step S104, converter control unit 32 calculates loss B when the remaining capacity ratio between power storage device B1 and power storage device B2 is the power ratio.

  Subsequently, in step S106, converter control unit 32 calculates loss M due to power transfer between power storage device B1 and power storage device B2. Here, an example of a method for calculating the loss M will be described.

First, the output P is expressed by the following equation using the voltage V, the current I, and the internal resistance value R.
P = (V−R × I) I (7)
And the loss Lb in an electrical storage apparatus is represented by following Formula.

Lb = R × I ² (8)
From the equations (7) and (8), the loss Lb is expressed by the following equation using the internal resistance value R, the voltage V, and the output P.

  The remaining capacity ratio of power storage device B1 and power storage device B2 is 1: a, and the average value of required power PR is Pv. When the remaining capacity ratio is the power ratio, the output of the power storage device B1 is 1 / (1 + a) × Pv, and the output of the power storage device B2 is a / (1 + a) × Pv. Therefore, the loss Lb1 when no power transfer is performed is expressed by the following equation.

  On the other hand, if the amount of power transfer from power storage device B2 to power storage device B1 is Pm, the output of power storage device B1 is 1 / (1 + a) × Pv−Pm, and the output of power storage device B2 is a / (1 + a). XPv + Pm. Therefore, the loss Lb2 when performing power transfer is expressed by the following equation.

  Assuming that the amount of power moving from the power storage device B2 to the power storage device B1 is W, the time t required for the power transfer is W × 3600 / Pm, and the loss M is (Lb2−Lb1) × t.

  Subsequently, in step S108, converter control unit 32 determines whether or not the sum of loss A and loss M is greater than loss B. If a positive determination is made in this process (YES in step S108), the process proceeds to step S109. On the other hand, if a negative determination is made in step S108 (NO in step S108), the process proceeds to S110.

  In step S109, converter control unit 32 determines the power ratio as power ratio Z, which is the remaining capacity ratio between power storage device B1 and power storage device B2.

  As described above, in another modification of the first embodiment, the sum of the loss in the power ratio that minimizes the internal resistance loss of power storage device B1 and power storage device B2 and the loss required for power transfer is When the loss in the power ratio due to the remaining capacity ratio between the device B1 and the power storage device B2 is larger than the power transfer, power transfer is not performed. Therefore, deterioration of efficiency due to power transfer can be suppressed.

[Embodiment 2]
The second embodiment of the present invention is different from the first embodiment in that the power adjustment unit has a diode. Thereby, a voltage equal to or higher than voltage VB2 of power storage device B2 can be supplied to inverters 20 and 22.

  FIG. 9 is an overall block diagram of a hybrid vehicle equipped with a power supply device according to Embodiment 2 of the present invention. Referring to FIG. 9, this hybrid vehicle 100 </ b> A includes a power adjustment unit 80 </ b> A instead of power adjustment unit 80.

  Power adjustment unit 80A includes a diode D3 in addition to converter 10 described above. Diode D3 is provided on positive line PL2 branched from positive line PL3 and connected to power storage device B2. Diode D3 is provided so as to regulate the flow of current to power storage device B2.

  As described above, in the second embodiment, since diode D3 is provided, no current flows in the direction of charging power storage device B2. Therefore, converter 10 can boost voltage VH to voltage VB2 or higher of power storage device B2. Therefore, a voltage equal to or higher than voltage VB2 of power storage device B2 can be supplied to inverters 20 and 22.

[Embodiment 3]
The third embodiment of the present invention is different from the second embodiment in that the power adjustment unit includes an npn transistor in addition to the diode. As a result, a voltage equal to or higher than voltage VB2 of power storage device B2 is supplied to inverters 20 and 22, while power storage device B2 can be charged.

  FIG. 10 is an overall block diagram of a hybrid vehicle equipped with a power supply device according to Embodiment 3 of the present invention. Referring to FIG. 10, hybrid vehicle 100B includes a power adjustment unit 80B instead of power adjustment unit 80A.

  Power adjustment unit 80B includes npn transistor Q3 in addition to converter 10 and diode D3 described above. Npn transistor Q3 is connected in antiparallel to diode D3 on positive line PL2. The npn transistor Q3 is switched between an on state and an off state by a signal PWC2 from the ECU 30. When charging power storage device B2, ECU 30 sends signal PWC2 for turning on npn transistor Q3 to npn transistor Q3.

  As described above, in the third embodiment, since npn transistor Q3 is provided, when npn transistor Q3 is off, no current flows in the direction of charging power storage device B2. On the other hand, when npn transistor Q3 is on, if voltage VH is equal to or higher than voltage VB2, a current flows in the direction of charging power storage device B2. Therefore, a voltage equal to or higher than voltage VB2 of power storage device B2 can be supplied to inverters 20 and 22, while power storage device B2 can be charged.

  In each of the above-described embodiments, the control in converter control unit 32 is actually performed by a CPU (Central Processing Unit), and the CPU includes a program comprising the steps of the flowcharts shown in FIGS. Is read from a ROM (Read Only Memory), the read program is executed, and the process is executed according to the flowcharts shown in FIGS. Therefore, the ROM corresponds to a computer (CPU) readable recording medium in which a program including the steps of the flowcharts shown in FIGS. 6 to 8 is recorded.

  In each of the above embodiments, a so-called series / parallel type hybrid vehicle in which the power of the engine 2 is distributed to the motor generator MG1 and the wheels 6 using the power split device 4 has been described. The present invention is also applicable to a so-called series type hybrid vehicle that uses only the power generated by the motor generator MG1 and generates the driving force of the vehicle using only the motor generator MG2.

  Further, the present invention can be applied to an electric vehicle that does not include the engine 2 and runs only by electric power, and a fuel cell vehicle that further includes a fuel cell as a power source.

  In the above, power storage devices B1 and B2 correspond to “first power storage device” and “second power storage device” in the present invention, respectively, and converter 10 corresponds to “boost circuit” in the present invention. ECU 30 corresponds to “control device” in the present invention, and diode D3 corresponds to “rectifier element” in the present invention. Further, npn transistor Q3 corresponds to “switching element” in the present invention, and inverters 20 and 22 correspond to “load” in the present invention.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

2 engine, 4 power split device, 6 wheels, 10 converter, 20, 22 inverter, 30 ECU, 32 converter control unit, 34, 36 inverter control unit, 42, 44, 46 voltage sensor, 52, 54 current sensor, 80, 80A, 80B power adjustment unit, 100, 100A, 100B hybrid vehicle, B1, B2 power storage device.

Claims (14)

A first power storage device for supplying power to a load;
A second power storage device provided in parallel to the first power storage device and supplying power to the load;
A power adjustment unit that is provided between the first power storage device and the load and adjusts input / output power of the first power storage device;
A power supply device comprising: a control device that controls the power adjustment unit based on a required power for the load, an internal resistance loss of the first power storage device, and an internal resistance loss of the second power storage device.   The control device is configured to input / output power of the first power storage device based on the required power, a voltage value and an internal resistance value of the first power storage device, and a voltage value and an internal resistance value of the second power storage device. The power supply device according to claim 1, wherein the power adjustment unit is controlled to adjust input / output power of the second power storage device.   The control device is configured to reduce input / output power of the first power storage device and input / output of the second power storage device in a direction in which the total of the internal resistance loss of the first power storage device and the internal resistance loss of the second power storage device decreases. The power supply device according to claim 2, wherein a power ratio with the power is adjusted.   The control device adjusts the power so that a remaining capacity ratio between a remaining capacity of the first power storage device and a remaining capacity of the second power storage device is adjusted to a predetermined ratio when the required power is smaller than a predetermined value. The power supply device according to claim 1, wherein the power supply device is controlled.   5. The control device according to claim 4, wherein the control device calculates in advance power movement loss that occurs when the remaining capacity ratio is adjusted to the predetermined ratio, and controls the power adjustment unit based on the power movement loss. 6. Power supply.   The power supply device according to claim 1, wherein the power adjustment unit includes a booster circuit configured to boost a voltage of the first power storage device and supply the boosted voltage to the load.   The power supply according to claim 6, wherein the power adjustment unit further includes a rectifying element that is provided between an output of the booster circuit and the second power storage device and regulates a current flow to the second power storage device. apparatus.   The power supply device according to claim 7, wherein the power adjustment unit further includes a switching element provided in parallel with the rectifying element.   A vehicle comprising the power supply device according to claim 1. A method of controlling a power supply device,
The power supply device
A first power storage device for supplying power to a load;
A second power storage device provided in parallel to the first power storage device and supplying power to the load;
A power adjustment unit that is provided between the first power storage device and the load and adjusts input / output power of the first power storage device;
The control method is:
Obtaining a required power for the load, an internal resistance loss of the first power storage device, and an internal resistance loss of the second power storage device;
A method for controlling a power supply device, comprising: controlling the power adjustment unit based on the required power, an internal resistance loss of the first power storage device, and an internal resistance loss of the second power storage device.   The controlling step includes: input / output of the first power storage device based on the required power, the voltage value and the internal resistance value of the first power storage device, and the voltage value and the internal resistance value of the second power storage device. The method for controlling the power supply device according to claim 10, comprising the step of controlling the power adjustment unit so as to adjust power and input / output power of the second power storage device.   The controlling step includes the input / output power of the first power storage device and the input of the second power storage device in such a direction that the total of the internal resistance loss of the first power storage device and the internal resistance loss of the second power storage device decreases. The method for controlling the power supply device according to claim 11, further comprising a step of adjusting a power ratio with the output power.   The controlling step includes adjusting the remaining capacity ratio between the remaining capacity of the first power storage device and the remaining capacity of the second power storage device to a predetermined ratio when the required power is smaller than a predetermined value. The method for controlling a power supply device according to claim 10, comprising a step of controlling the adjustment unit. The step of controlling calculates in advance a power transfer loss that occurs when the remaining capacity ratio is adjusted to the predetermined ratio;
The method for controlling the power supply device according to claim 13, further comprising: controlling the power adjustment unit based on the power transfer loss.

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