JP6089552B2 - Power control device - Google Patents

Description

  The present invention relates to a power control device that controls charge / discharge states of a secondary battery and a fuel cell.

  In recent years, application of a power generation system using a fuel cell to an electric vehicle or a hybrid vehicle using a secondary battery as a drive source has been studied. That is, when the charge rate (State of Charge, SOC) of the secondary battery decreases, the fuel cell generates power, and this is used for charging the secondary battery or driving the vehicle to compensate for the power shortage. By utilizing the fuel cell as an auxiliary power supply source, the cruising range can be extended with a small amount of fuel without increasing the battery capacity of the secondary battery.

On the other hand, the fuel cell has high power generation efficiency, but its electric output is relatively small and it is difficult to cope with load fluctuations. In addition, since the power generation efficiency of the fuel cell is biased toward the low output side, good power generation efficiency cannot be obtained depending on the traveling conditions of the vehicle, and fuel consumption and running cost increase.
To cope with these problems, it is conceivable to appropriately control the load of each battery by combining a plurality of secondary batteries and a fuel cell. That is, a plurality of secondary batteries are classified into a discharge target and a charge target, and the vehicle is driven using the discharge target, and the charge target is charged with the fuel cell in a form independent of the drive system. The charge / discharge role of the secondary battery is changed when the charge rate of the discharge target is reduced to some extent.

  By such control, the vehicle can be driven by the other secondary battery while charging one secondary battery by the fuel cell, and it is possible to appropriately cope with the load fluctuation. In addition, since the driving load of the vehicle does not act directly on the fuel cell, the fuel cell can have a low output, and the power generation efficiency can be improved (see, for example, Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 6-14720 Japanese Patent No. 4783454

However, in a power generation system including a plurality of secondary batteries, control stability may be impaired when variations occur in the deterioration state of individual secondary batteries. For example, if the output characteristics when a secondary battery with a high degree of deterioration is used for a discharge application differ from the output characteristics when a secondary battery with a low degree of deterioration is used for a discharge application, these secondary batteries There are cases where the driving force of the vehicle fluctuates due to battery switching.
In addition, the secondary battery having deteriorated has a shorter discharge time due to a decrease in charge capacity. Thereby, the charge time of another secondary battery will also be shortened and it will become difficult to operate in an appropriate charge / discharge cycle.

One of the objects of the present case has been devised in view of the problems as described above, and is to provide a power control device that can equalize deterioration states of a plurality of secondary batteries.
The present invention is not limited to this purpose, and is a function and effect derived from each configuration shown in the embodiments for carrying out the invention described later, and other effects of the present invention are to obtain a function and effect that cannot be obtained by conventional techniques. Can be positioned.

(1) A power control device disclosed herein is connected to an electrical device, and is connected to a plurality of secondary batteries whose charge / discharge states are controlled independently of each other, and to the plurality of secondary batteries, and each of the two A fuel cell for charging the secondary battery. A control unit configured to set a discharge target and a charge target from the plurality of secondary batteries, and to control a discharge state from the discharge target to the electric device and a charge state from the fuel cell to the charge target; Prepare. Furthermore, based on the rate of decrease of the charging rate of the secondary battery set as the discharge target , the fuel cell supplied to the secondary battery set as the charge target when the rate decrease is detected Electrical output control means for increasing / decreasing the electrical output.
In addition, an electric device here means the machine, instrument, and instrument generally which operate | move with electric power. In addition, the term “discharge target” used herein means “secondary battery set as discharge target”, and the term “charge target” means “secondary battery set as discharge target”. Means a secondary battery set as a charging target when a decrease in the charging rate is detected.

  (2) Further, it is preferable that the increase / decrease control of the electric output of the fuel cell by the electric output control means is further controlled based on the charging rate of the charging target. In other words, it is preferable that the electrical output control means increase / decrease the electrical output of the fuel cell based on both the rate of decrease of the charge rate of the discharge target and the charge rate of the charge target.

(3) Moreover, it is preferable that the said electrical output control means increases the electrical output of the said fuel cell, so that the charging rate of the said charging object is low, and the fall rate of the charging rate of the said discharge object is large.
That is, it is preferable that the lower the charging rate of the charging target is, the more the electric output of the fuel cell is increased and the charging is completed quickly. Moreover, as for a general secondary battery, as the deterioration progresses, the rate of decrease in the charging rate increases. Therefore, it is preferable to increase the electric output of the fuel cell and complete the charging quickly as the rate of decrease in the charging rate of the discharge target increases.

(4) Further, when the electric output control means sets the electric output of the fuel cell, the charging rate of the charging target is set to the magnitude of the electric output of the fuel cell rather than the rate of decrease of the charging rate of the discharging target. It is preferable to reflect it strongly.
That is, using the map in which the charging rate of the charging target is more strongly reflected in the magnitude of the electrical output of the fuel cell than the rate of decrease of the charging rate of the discharging target, the electrical output control means It is preferable to set the electrical output.

For example, if the charging rate decrease speed X is the maximum speed assumed for this vehicle and the charging rate of the rechargeable battery is maximum, the value of the basic output is set as Q ₁ and the charging rate decrease speed X is zero. the value of the basic output when the charging rate of the rechargeable battery is minimal when placed and Q _2, it is preferable to set the electrical output of the fuel cell so as to satisfy the relationship of Q ₁ <Q _2.
Alternatively, if the charging rate reduction rate of the discharge battery is constant and the charging rate of the charging battery is changed, the fluctuation range width of the basic output that can be taken is set as W ₁ and the charging rate of the charging battery is constant. It is preferable to set the electric output of the fuel cell so as to satisfy the relationship of W ₁ > W ₂ when the fluctuation range width of the basic output that can be obtained when the decrease rate is changed is W ₂ .

  (5) Moreover, it is preferable to provide the determination means which determines the relative deterioration degree about each of these secondary batteries. In this case, the electrical output control means, based on the relative deterioration degree of the charging target with respect to the discharge target, when the charging target is determined by the determination means to be relatively small It is preferable to correct the electric output of the fuel cell. For example, it is preferable that the electrical output control means decreases the electrical output of the fuel cell as the degree of relative deterioration of the charging target with respect to the discharging target increases.

That is, when the secondary battery to be discharged is deteriorated more than the secondary battery to be charged, the electric output of the fuel cell related to charging the secondary battery on the non-deteriorated side is increased. It is preferable to carry out charging.
(6) The disclosed power control apparatus is connected to an electrical device, and is connected to the plurality of secondary batteries whose charge / discharge states are controlled independently of each other, and the plurality of secondary batteries, and each of the secondary batteries A discharge target and a charge target from among the plurality of secondary batteries, a discharge state from the discharge target to the electrical device, and a charge state from the fuel cell to the charge target Control means for controlling, electrical output control means for increasing / decreasing the electrical output of the fuel cell supplied to the charging target based on the rate of decrease of the charging rate of the discharging target, and each of the plurality of secondary batteries Determining means for determining the relative deterioration degree of the. The electrical output control means, when the charge target is determined by the determination means to be relatively small in degree of deterioration, is based on the relative deterioration degree of the charge target with respect to the discharge target. Correct the electrical output.

According to the disclosed power control device, by controlling the electrical output of the fuel cell based on the rate of decrease of the charging rate of the secondary battery on the discharge side, the output of the fuel cell according to the discharge rate of each secondary battery It becomes possible to control, and it is possible to prevent electric shortage of the secondary battery while suppressing the progress of deterioration of the fuel cell.
In addition, among the plurality of secondary batteries, the secondary battery on the relatively deteriorated side is suppressed in progress of deterioration by reducing the electric output of the fuel cell at the time of charging. Therefore, the deterioration state of a plurality of secondary batteries can be equalized through the output control of the fuel cell. Thereby, the useful life of a secondary battery can be extended and cost performance can be improved.

1 is a side view showing an overall configuration of a vehicle to which a power control device of an embodiment is applied. It is the schematic diagram and block diagram which show the whole structure of this electric power control apparatus. It is a figure which shows typically the charging / discharging state of the secondary battery and fuel cell which are controlled by this electric power control apparatus, (a) corresponds at the time of external charge, (b), (c) corresponds at the time of normal driving. is there. A calculation map example of the basic electrical output Q _FC of the fuel cell is set in the power control apparatus. (A) ~ (g) is a calculation map example of the correction coefficient K ₁ ~K ₇ set by the electronic control device of FIG. It is a flowchart which shows the example of control (flag setting) in this electric power control apparatus. It is a flowchart which shows the example of control (parameter calculation) in this electric power control apparatus. It is a flowchart which shows the control example (charge / discharge control) in this electric power control apparatus. It is a flowchart which shows the example of control (switching determination) in this electric power control apparatus. It is a flowchart which shows the control example (external charge) in this electric power control apparatus. It is a graph for demonstrating the control effect | action of this electric power control apparatus, (a) shows the secular change of the degradation degree DL of two secondary batteries, (b) is the aging of the charging / discharging area | region of one secondary battery. Showing change. It is a time chart which shows the charge / discharge state of the secondary battery by this electric power control apparatus, (a) shows the change of the charging rate SOC of a 1st battery, (b) shows the change of the charging rate SOC of a 2nd battery. .

  A power control apparatus applied to a vehicle will be described with reference to the drawings. Note that the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the following embodiment. Each configuration of the present embodiment can be implemented with various modifications without departing from the spirit of the present embodiment, and can be selected or combined as necessary.

[1. Device configuration]
A vehicle 20 to which the power control apparatus 1 of the present embodiment is applied is shown in FIG. The vehicle 20 is a hybrid fuel cell vehicle equipped with an electric motor 4 (electric equipment) and a plurality of secondary batteries 2 and a fuel cell 3 as a battery for running the motor 4.

  The secondary battery 2 is a power storage device that can be charged with regenerative power generated by the vehicle 20, an external power source, or power supplied from the fuel cell 3, and is, for example, a lithium ion secondary battery or a lithium ion polymer secondary battery. Each of the plurality of secondary batteries 2 is connected to the motor 4 and the fuel cell 3, and the charge / discharge state is controlled independently of each other.

  The fuel cell 3 is a power generation device that extracts electric power by utilizing an electrochemical reaction between hydrogen in fuel and oxygen in air, and is, for example, a solid polymer fuel cell or a phosphoric acid fuel cell. The electric power (electrical output) generated in the fuel cell 3 is mainly used for charging the secondary battery 2. When the load of the motor 4 is large enough to exceed the power supply capability of the secondary battery 2, the power of the fuel cell 3 is supplied directly to the motor 4. The fuel in the fuel cell 3 is stored in the fuel tank 5.

  On the electric circuit connecting the secondary battery 2 and the fuel cell 3, a converter 6 (DC-DC converter) for voltage conversion is interposed. The converter 6 boosts the DC power generated in the fuel cell 3 and supplies it to the secondary battery 2 and the motor 4 side. In addition, an inverter 7 (DC-AC inverter) is interposed on the electric circuit connecting the secondary battery 2 and the motor 4, where DC power and AC power are converted.

  The outer surface of the vehicle 20 is provided with an inlet 21 (power inlet) for connecting the charging cable 22 during external charging. The on-vehicle charger 8 is provided on a circuit connecting the secondary battery 2 and the inlet 21. The on-vehicle charger 8 is a power conversion device that converts AC power supplied from a household power source, a charging station, or the like outside the vehicle 20 into DC. The charging / discharging state of the secondary battery 2 and the operating state of the fuel cell 3, the motor 4, and the in-vehicle charger 8 are controlled by an electronic control device 10 described later.

[2. Circuit configuration]
FIG. 2 is a schematic diagram of a drive circuit for the motor 4. Here, the number of the secondary batteries 2 is two, the circuit between the motor 4 and the inverter 7 and the circuit between the in-vehicle charger 8 and the inlet 21 are three-phase AC circuits, and the others are DC circuits. Show things. Hereinafter, when distinguishing each of the two secondary batteries 2, the first battery 2 a and the second battery 2 b will be referred to for explanation.

  The DC circuit in FIG. 2 has a structure in which the first battery 2 a, the second battery 2 b, the converter 6, the inverter 7, and the in-vehicle charger 8 are connected to each other via the control circuit 9. The control circuit 9 is a circuit for comprehensively managing the magnitude of electric power exchanged between the devices and the feeding direction, and its operation is controlled by the electronic control device 10.

  The electronic control device 10 is, for example, an LSI device or an embedded electronic device in which a microprocessor, ROM, RAM, and the like are integrated. A temperature sensor for detecting the battery temperature T of each of the first battery 2 a and the second battery 2 b is connected to the signal input side of the electronic control device 10, and each secondary battery 2, fuel cell 3, motor 4 , Converter 6, inverter 7 and on-vehicle charger 8 are connected, and information on the operating state of each device is transmitted to electronic control device 10.

  Specific examples of information input to the electronic control device 10 include charging / discharging voltage information and charging / discharging current information of each secondary battery 2, information on the battery temperature T, rotation speed information of the cooling fan of the secondary battery 2, The output voltage information and output current information of the fuel cell 3, the required electrical output information of the motor 4, information on the presence or absence of external charging, and the like. The electronic control device 10 controls the operating state of each device based on these pieces of information.

[3. Charge / discharge state]
FIG. 3 schematically shows the charge / discharge state (power flow) of the secondary battery 2 controlled by the electronic control device 10. 3A corresponds to the state during external charging of the vehicle 20, and FIGS. 3B and 3C correspond to the state during normal running. The normal running here includes not only the movement of the vehicle 20 but also the entire non-external charging such as during a temporary stop or stop.

  At the time of external charging, as shown in FIG. 3A, all the secondary batteries 2 are charged with the fuel cell 3 and the motor 4 stopped. At this time, the electric power supplied from the in-vehicle charger 8 side is simultaneously supplied to the respective secondary batteries 2. When there is a difference in the charging rate or the upper limit charging rate of each secondary battery 2, external charging is terminated in order from the one where the charging rate has reached the upper limit charging rate.

  On the other hand, during normal travel, as shown in FIG. 3B, the plurality of secondary batteries 2 are separated into a charging system and a discharging system, and the power of the fuel cell 3 is supplied to the secondary batteries 2 of the charging system. Is done. At this time, the motor 4 is driven by the power of the secondary battery 2 of the discharge system. That is, the secondary battery 2 in the charging system is charged by the fuel cell 3 while the secondary battery 2 in the discharging system is driving the motor 4.

Further, when the charging of all the secondary batteries 2 in the charging system is completed, the fuel cell 3 stops power generation. By making the charging system a circuit independent of the discharging system, the fuel cell 3 is less likely to be directly affected by the load fluctuation of the motor 4. However, when the electrical output of the secondary battery 2 of the discharge system is insufficient with respect to the required electrical output Q _M of the motor 4, the power of the fuel cell 3 is reduced as shown by the broken line arrow in FIG. You may supply to the motor 4, and you may supply the electric power of the secondary battery 2 of both a charging system and a discharge system to the motor 4. FIG.

  Further, when a predetermined switching condition is satisfied during normal traveling, the secondary batteries 2 of the charging system and the discharging system are changed. When the number of secondary batteries 2 is two, the role of charging / discharging of each secondary battery 2 is switched. For example, as shown in FIG. 3C, the current discharge target becomes a new charge target, and at the same time, the previous charge target becomes a new discharge target. At this time, if the fuel cell 3 is in a state where the power generation is stopped, the power generation is restarted with the switching of the charge / discharge target.

Each of the plurality of secondary batteries 2 has parameters for controlling the charge / discharge state, such as deterioration degree DL, charge rate SOC (actual charge rate), upper limit charge rate SOC _MAX , lower limit charge rate SOC _MIN, and external charging. Five types of control parameters, upper limit charging rate SOC _{MAX_EX} , are set. Of these, the upper limit charge rate SOC _MAX and the lower limit charge rate SOC _MIN are values corresponding to the maximum and minimum values of the fluctuation range of the charge rate SOC during normal driving. The upper limit charge rate SOC _{MAX_EX} during external charging is This is a value corresponding to the maximum value of the charging rate SOC at the time of charging.

In the present embodiment, even if the same secondary battery 2 is used, different control is performed depending on whether the secondary battery 2 is a discharge battery or a charge battery. Hereinafter, when these are described separately, the upper limit charge rate of the discharge battery, the lower limit charge rate of the discharge battery, the upper limit charge rate of the charge battery, and the lower limit charge rate of the charge battery are respectively _denoted by SOC _{MAX_DIS} , It is _expressed as SOC _{MIN_DIS} , SOC _{MAX_CHA} , SOC _{MIN_CHA} .

[4. Control configuration]
As shown in FIG. 2, the electronic control device 10 includes a deterioration degree determination unit 11, a target setting unit 12, an external charge control unit 13, and a charge / discharge control unit 14. Each of these elements may be realized by an electronic circuit (hardware), or may be programmed as software, or some of these functions may be provided as hardware, and the other part may be software. It may be what.

[4-1. Deterioration degree determination unit]
The deterioration degree determination unit 11 (determination means) calculates and determines the degree of deterioration for each of the plurality of secondary batteries 2, and determines the relative degree of deterioration. It is classified into “deteriorated battery” and “smallly deteriorated battery”. These classifications are relative, and the reference value of the classification is changed according to the degree of deterioration of each secondary battery 2. For example, a reference value that is larger than that having the smallest degree of deterioration and smaller than that having the largest degree of deterioration is set. In this case, if the number of secondary batteries 2 is two, either one is classified as a highly deteriorated battery and the other is classified as a small deteriorated battery. Further, if the number of secondary batteries 2 is three or more, at least one secondary battery 2 is classified into a large deterioration battery and a small deterioration battery.

  However, when the difference between the smallest deterioration degree and the largest deterioration degree is smaller than the predetermined difference, the deterioration degree of the plurality of secondary batteries 2 can be regarded as almost equal. It is judged that there is no battery that falls under the category of deteriorated batteries and small deteriorated batteries. For example, when the number of secondary batteries 2 is two and the degree of deterioration is similar (for example, when the secondary battery 2 is new), the degree of deterioration is not classified, and either When the deterioration has progressed to some extent, each of the large deterioration battery and the small deterioration battery is determined.

  As the index value when the degree of deterioration is compared, for example, the degree of deterioration of battery capacity, the degree of deterioration of output current / voltage characteristics, the degree of deterioration of acceptance current / voltage characteristics, and the like can be used. The deterioration degree determination unit 11 of the present embodiment calculates the ratio of the full charge capacity at the completion of charging to the full charge capacity at the time of a new article as the deterioration degree DL, and the deterioration degree DL of the first battery 2a and the deterioration of the second battery 2b. The absolute value of the difference from the degree DL is calculated as the deterioration degree difference ΔDL.

The deterioration degree is classified as follows. When the deterioration degree difference ΔDL between the first battery 2a and the second battery 2b exceeds a predetermined value D ₀ , it is determined that one of the deterioration degrees DL is a large deterioration battery. The other with a small DL is a small deterioration battery. In general, the degree of deterioration DL of the secondary battery 2 is minimum (zero) when new, and increases as it is used for a long time. Accordingly, the new secondary battery 2 is not classified as either a large deterioration battery or a small deterioration battery, and is classified when the distribution of the deterioration degree DL is not uniform (biased).

  The degree of deterioration DL of each secondary battery 2 is calculated during charging of the battery, after completion of charging, during discharging, or the like. For example, as shown in FIG. 3C, when the first battery 2a is to be charged, the degree of deterioration of the first battery 2a is estimated by estimating the full charge capacity from the relationship between the power supply amount during charging and the voltage increase gradient. DL is calculated, and this is updated and stored in the memory or storage device. Alternatively, the full charge capacity is measured at the completion of charging to calculate the deterioration degree DL, and this is updated and stored in a memory or a storage device. When the charge / discharge role is switched as shown in FIG. 3B, the degradation degree DL of the second battery 2b is calculated in the same procedure, and this is updated and stored in a memory or a storage device. The value of the deterioration level difference ΔDL calculated based on the deterioration levels DL of the first battery 2a and the second battery 2b is transmitted to the target setting unit 12, the external charge control unit 13, and the charge / discharge control unit 14.

  When the number of secondary batteries 2 is three or more, the deterioration degree difference ΔDL may be obtained based on the maximum value and the minimum value of the deterioration degree DL, and the dispersion and deviation of the deterioration degree DL are deteriorated. It may be used as an index instead of the degree difference ΔDL. In this case, when the deterioration degree difference ΔDL, variance, and deviation values increase to some extent, the large deterioration battery and the small deterioration battery may be classified based on the index values.

[4-2. Target setting section]
The target setting unit 12 selects, from the plurality of secondary batteries 2, a discharge battery (discharge target) in charge of discharging during normal driving (non-external charging) and a charge battery (charge target) to be charged, The role is set. The discharge battery is a secondary battery 2 responsible for supplying power to the motor 4 during normal driving, and the rechargeable battery supplies power from the fuel cell 3 while the discharge battery functions as a power source for the motor 4. It is the secondary battery 2 charged by receiving.

  The target setting unit 12 selects a discharge battery from a plurality of secondary batteries 2 according to a predetermined selection order, and selects a charge battery from those other than those selected for the discharge battery. The roles of the discharge battery and the rechargeable battery set here are maintained until a predetermined switching condition is satisfied. When a predetermined switching condition is satisfied, the target setting unit 12 selects a new discharge battery and a rechargeable battery and sets their roles.

  The selection order of the discharge batteries is determined along a predetermined order (scheduling) set in advance. Further, the selection order of the rechargeable batteries follows the selection order of the discharge batteries. For example, the previous discharge battery is the current rechargeable battery. However, if external charging is performed in a state where it is determined that there is a battery that is highly degraded, when the external charging is completed, the selection order of the discharge batteries is changed in descending order of the degree of degradation DL. To do. Alternatively, the first discharge battery after the completion of external charging is selected from those that correspond to at least a highly deteriorated battery.

  This is because the charge rate SOC of all the secondary batteries 2 is in a maximum state after external charging, so that the large deterioration battery is discharged preferentially over the small deterioration battery to suppress the progress of deterioration. is there. Therefore, it is preferable to use the small deteriorated battery after all the large deteriorated batteries have been used as discharge batteries at least once. The setting information of the charging battery and discharging battery set here is transmitted to the charging / discharging control unit 14.

[4-3. External charge control unit]
The external charging control unit 13 (external charging control means) is in charge of charging control of the secondary battery 2 during external charging. When a predetermined external charging start condition is satisfied, the external charging control unit 13 stops the operation of the fuel cell 3 and supplies the power supplied from the external power source to all the secondary batteries 2 for charging. The external charging start condition is determined based on, for example, whether or not the charging cable is inserted into the inlet 21, a power supply state from the outside, an operating state of the in-vehicle charger 8, and the like.

Further, when the charging of all the secondary batteries 2 is completed, the external charging control unit 13 stops the charging by cutting off the power supplied from the external power source. The charging speed for each secondary battery 2 varies depending on the initial value of charging rate SOC and charging characteristics. Therefore, the external charge control unit 13 cuts off the power supply in the order from when the charge rate SOC reaches the external charge upper limit charge rate SOC _{MAX_EX,} and the charge rates SOC of all the secondary batteries 2 become the external charge upper limit charge rate SOC. When the power _{exceeds MAX_EX} , the power of the external power supply is shut off.

The external charge upper limit charging rate SOC _{MAX_EX} is set according to the deterioration degree difference ΔDL of the secondary battery 2 calculated by the deterioration degree determination unit 11. The external charging control unit 13 sets a correction coefficient K ₁ for each secondary battery 2 classified as a highly deteriorated battery based on the deterioration degree difference ΔDL. Further, as shown in Equation 1 is calculated are multiplied by the external charging during a typical upper limit charge rate SOC _HPIBASE the correction factor K ₁ as each of the secondary battery 2 for external charging when the upper limit charging rate SOC _{MAX_EX.} The upper limit charging rate SOC _{MAX_EX} at the time of external charging of the secondary battery 2 classified as a small deterioration battery is the same value as the standard upper limit charging rate SOC _HPIBASE at the time of external charging. Further, the standard upper limit charging rate SOC _HPIBASE at the time of external charging is set to a value within a range of 90 to 100%, for example.
SOC _{MAX_EX} = K ₁ × SOC _HPIBASE Equation 1

The correction factor K ₁ is a coefficient that act to reduce the charge rate SOC when fully charged large deterioration battery as compared with the small deterioration battery. For example, as shown in FIG. 5 (a), when the deterioration degree difference ΔDL is less than the predetermined value D _1, the value of the correction factor K ₁ is regarded as deterioration degree DL is substantially equal is set to 1.0. Further, when the deterioration degree difference ΔDL _one or more predetermined value D, the value of the correction coefficient K ₁ as the deterioration degree difference ΔDL increases is set to a value smaller than 1.0.

[4-4. Charge / discharge control unit]
The charge / discharge control unit 14 (control means) is in charge of controlling the discharge system and the charging system during normal travel. The functions of the charge / discharge control unit 14 are classified into a basic electrical output calculation unit 15, a charge / discharge area calculation unit 16, a charge / discharge output calculation unit 17, a switching determination unit 18, and a charge suspension determination unit 19.

[A. Basic electrical output calculator]
The basic electrical output calculation unit 15 (electrical output control means) calculates the basic electrical output Q _FC of the fuel cell 3. The basic electrical output Q _FC is a standard electrical output when charging the secondary battery 2. Here, the basic electrical output Q _FC is calculated based on the charging rate decrease rate X of the discharge battery and the charging rate SOC of the charging battery among the plurality of secondary batteries 2. The relationship between the discharge rate reduction rate X of the discharge battery, the charge rate SOC of the charge battery, and the basic electrical output Q _FC is defined by, for example, a map, a mathematical expression, or the like. Basic electrical output calculating section 15, such a map, calculates a basic electrical output Q _FC of the fuel cell 3 on the basis of the formula or the like. The value of the basic electrical output Q _FC calculated here is transmitted to the charge / discharge output calculation unit 17.

If the charging rate decrease rate X of the discharge battery is large, the discharge battery will be consumed at an early stage, and the timing for switching the role of charge / discharge is considered to be accelerated. In this embodiment, as shown in FIG. 4, it is set high enough basic electrical output Q _FC charging rate decreases speed X is higher discharge cell. Also, the lower the charging rate SOC of the rechargeable battery, since the time to completion of charging becomes longer, set a high basic electrical output Q _FC.

When setting the basic electrical output Q _FC , the charging rate SOC of the rechargeable battery is more strongly reflected in the value of the basic electrical output Q _FC than the charging rate decrease rate X described above. In other words, a map as towards the influence of charge SOC of the rechargeable battery is strongly reflected on the value of the basic electrical output Q _FC than the influence of the charging rate decreases the rate X, and formulas such as are defined.
For example, the value of the basic electrical output Q _FC when the charging rate decreasing speed X is the maximum speed assumed in the vehicle 20 and the charging rate SOC of the rechargeable battery is maximum is set to Q ₁ . Further, a charging rate slowdown X is zero, and placing the value of the basic electrical output Q _FC when charging rate SOC of the rechargeable battery is minimum and Q _2. Value to Q ₁ basic electrical output Q _FC is set in the present embodiment is a value smaller than the value Q _2.

Alternatively, the fluctuation range width of the basic electrical output Q _{FC that} can be obtained when the charging rate SOC of the charging battery is changed while the charging rate decrease rate X of the discharging battery is constant is set to W ₁ . Also, let W ₂ be the fluctuation range width of the basic electrical output Q _{FC that} can be obtained when the charge rate SOC of the rechargeable battery is constant and the charge rate decrease rate X of the discharge battery is changed. Fluctuation range width W ₁ of the basic electrical output Q _FC is set in the present embodiment is a value larger than the variation range width W _2.
Setting a map where the basic electrical output Q _FC value satisfies the relationship of Q ₁ <Q ₂ or setting a map where the basic electrical output Q _FC variation range width satisfies the relationship of W ₁ > W ₂ This corresponds to “the charging rate SOC of the charging target is more strongly reflected in the magnitude of the electrical output of the fuel cell 3 than the charging rate decrease rate X of the discharging target”.

[B. Charge / discharge area calculator]
Discharge region computing unit 16 (charge-discharge zone control means) is for setting based on the lower limit charging rate SOC _{MIN_DIS} discharge cell and the upper limit charge rate SOC _{MAX_CHA} charging battery deterioration degree difference dL. The upper limit charging rate SOC _{MAX_CHA} of the rechargeable battery serves as an index for determining whether or not the charging by the fuel cell 3 is completed. Further, the lower limit charging rate SOC _{MIN_DIS} of a discharge battery is an index for grasping the remaining power of the discharge battery. These two are used to determine the timing for switching the charge / discharge roles.

  The charge / discharge state of the secondary battery 2 during normal running is controlled so that the charge rate SOC increases or decreases between these two threshold values. Thus, the fluctuation range of the charging rate SOC surrounded by the two threshold values is called a charge / discharge region, and the difference between the two threshold values is called an allowable fluctuation width (usage window width) of the charging rate SOC. The charge / discharge area calculation unit 16 functions to set the allowable fluctuation range according to the deterioration degree DL of the secondary battery 2.

In the power control apparatus 1 of the present embodiment, two threshold values are set so that a moderate state (50% charge rate state) in which the charge rate SOC is neither excessive nor excessive is always included in the charge / discharge region. That is, the upper limit charge rate SOC _{MAX_CHA} of the rechargeable battery is at least 50% or more, and the lower limit charge rate SOC _{MIN_DIS} of the discharge battery is at least 50% or less. Further, as the deterioration degree DL of the secondary battery 2 increases, the respective threshold values are set so that the allowable fluctuation range of the secondary battery 2 gradually becomes narrower toward the state of 50%.

The upper limit charging rate SOC _{MAX_CHA} of the rechargeable battery is set according to the deterioration degree difference ΔDL of the secondary battery 2 calculated by the deterioration degree determination unit 11. The charge / discharge area calculation unit 16 sets the correction coefficient K ₂ based on the deterioration degree difference ΔDL. Further, as shown in Equation 2, to calculate what the correction factor K ₂ multiplied by the standard upper limit charge rate SOC _SFCBASE upper limit charge rate SOC _{MAX_CHA} charging the battery. The standard upper limit charge rate SOC _SFCBASE is set to a value smaller than the standard upper limit charge rate SOC _HPIBASE during external charging, for example, a value within a range of 80 to 90%. Note that the upper limit charging rate SOC _{MAX_CHA} of the rechargeable battery during normal traveling is set smaller than the upper limit charging rate SOC _{MAX_EX} during external charging.
SOC _{MAX_CHA} = K ₂ × SOC _SFCBASE … Formula 2

The correction factor K _2, similar to the correction factor K _1, a factor which acts to reduce the charge rate SOC when fully charged large deterioration battery as compared with the small deterioration battery. For example, as shown in FIG. 5 (b), when the deterioration degree difference ΔDL is less than a predetermined value D _2, the value of the correction factor K ₂ is regarded as deterioration degree DL is substantially equal is set to 1.0. Further, when the deterioration degree difference ΔDL is a predetermined value or more D _2, the value of the correction factor K ₂ as deterioration degree difference ΔDL increases is set to a value smaller than 1.0.

Therefore, the allowable fluctuation range of the charging rate SOC of the large deterioration battery is set narrower than that of the small deterioration battery. Further, since the value of the correction coefficient K ₂ as deterioration degree difference ΔDL increases is set to a value smaller than 1.0, the more the degradation progresses, the allowable variation width is narrowed maximum value of the charging rate SOC decreases Will be.

The charge / discharge area calculation unit 16 sets the correction coefficient K ₃ based on the deterioration degree difference ΔDL. Further, as shown in Equation 3 to calculate what the correction factor K ₃ times the standard limit storage rate SOC _LWBASE lower limit charging rate SOC _{MIN_DIS} discharge cell. The standard lower limit charging rate SOC _LWBASE is, for example, a value within a range of 10 to 20%.
SOC _{MIN_DIS} = K ₃ × SOC _LWBASE … Formula 3

The correction coefficient K ₃ is a coefficient that acts to increase the charge rate SOC corresponding to the discharge lower limit of the secondary battery 2, contrary to the correction coefficients K ₁ and K ₂ . For example, as shown in FIG. 5 (c), when the deterioration degree difference ΔDL is less than a predetermined value D _3, the value of the correction coefficient K ₃ is regarded as deterioration degree DL is substantially equal is set to 1.0. Further, when the deterioration degree difference ΔDL is a predetermined value or more D _3, the value of the more correction factor K ₃ degradation degree difference ΔDL increases is set to a value greater than 1.0.

[C. Charge / discharge output calculator]
The charge / discharge output calculation unit 17 (charge / discharge output control means) is the power actually generated by the fuel cell 3 (electrical output), the charge power input to the charge battery, and the power supplied from the discharge battery to the motor 4. Etc. are calculated. Here, the charging output Q supplied from the fuel cell 3 to the secondary battery 2, the power generation output Q _TGT of the fuel cell 3, the charging input C input to the charging battery (corresponding to the charging output Q), the discharging battery The discharge output D etc. output from is calculated. The power generation output Q _TGT is a final control target value of the electric output generated by the fuel cell 3, and includes an electric output for charging the secondary battery 2, an electric output for assisting the motor 4, and the like. Is included.

The charging output Q of the fuel cell 3 is calculated based on the basic electrical output Q _FC calculated by the basic electrical output calculation unit 15 and the deterioration degree difference ΔDL. Here, the charging output Q for charging the small deterioration battery is set higher than the charging output Q for charging the large deterioration battery. That is, the secondary battery 2 is charged with a high output when the small deterioration battery is charged, and the secondary battery 2 is charged with a low output when the large deterioration battery is charged. Therefore, the charge / discharge output calculation unit 17 sets the correction coefficient K ₄ based on the deterioration degree difference ΔDL and, as shown in Expression 4, the charge output is obtained by multiplying the correction coefficient K ₄ by the basic electrical output Q _FC. Calculate as Q.
Q = K ₄ × Q _FC … Formula 4

Correction factor K ₄ is a coefficient that acts to increase the charging input C to a small deterioration cell as compared to a large deterioration battery. For example, as shown in FIG. 5 (d), when the deterioration degree difference ΔDL is less than a predetermined value D _4, the value of the correction coefficient K ₄ is regarded as deterioration degree DL is substantially equal is set to 1.0. Further, when the deterioration degree difference ΔDL is a predetermined value or more D _4, the value of the more correction coefficient K ₄ deterioration degree difference ΔDL increases is set to a value greater than 1.0.

The charging output Q corresponds to the electrical output indicated by the thick arrow supplied from the fuel cell 3 to the charging cell in FIGS. At this time, an electrical output for driving the motor 4 is output from the discharge battery as indicated by a white arrow in the figure. On the other hand, when the required electric output Q _M of the motor 4 exceeds the maximum electric output Q _MAX of the discharge battery during the start-up of the fuel cell 3, as shown by the broken line arrow in the figure, the insufficient electric output is the fuel cell 3 And replenishment from the secondary battery 2 on the charging side, and high-power carry-out from the secondary battery 2 on the discharging side is suppressed. Thus, the electrical output corresponding to the shortage of output of the discharge battery is referred to as an electrical output assist amount Q _ASST .

The charge / discharge output calculation unit 17 of the present embodiment performs such electrical output compensation when the discharge battery is a highly deteriorated battery. This is because the deterioration of the secondary battery 2 decreases the discharge output characteristics enough to proceed, to meet the required electrical output Q _M of the motor 4 becomes difficult. By performing control for assisting the electrical output for the discharge battery having a relatively high degree of deterioration DL, the progress of deterioration of the discharge battery is suppressed, and the deterioration degree DL of the secondary battery 2 is equalized. However, such an electrical output assist can be performed even when the discharge battery is a small deterioration battery.

The charge / discharge output calculation unit 17 calculates the electric output assist amount Q _ASST based on a value obtained by subtracting the maximum electric output Q _MAX of the secondary battery 2 from the required electric output Q _M of the motor 4. For example, as shown in Expression 5, the value obtained by subtracting the maximum electrical output Q _MAX from the required electrical output Q _M and the correction coefficient L is used as the electrical output assist amount Q _ASST . The correction coefficient L is a value set in advance according to the conversion loss in the converter 6 and the inverter 7.
Q _ASST = (Q _M -Q _MAX ) × L ... Formula 5

Further, since the maximum electrical output Q _MAX of the secondary battery 2 decreases as the deterioration progresses, it is calculated based on the deterioration degree DL and the deterioration degree difference ΔDL of the discharge battery. For example, as shown in Expression 6, a correction coefficient K ₅ is set based on the deterioration degree difference ΔDL, and a value _obtained by multiplying the correction coefficient K ₅ by the standard maximum electric output Q _MAXBASE is set as the maximum electric output Q _MAX .
Q _MAX = K ₅ × Q _MAXBASE … Formula 6

The correction factor K ₅ is a coefficient that act to reduce the maximum electric output Q _MAX of the large deterioration battery as compared with the small deterioration battery. For example, as shown in FIG. 5 (e), when the deterioration degree difference ΔDL is less than a predetermined value D _5, the value of the correction coefficient K ₅ is regarded as deterioration degree DL is substantially equal is set to 1.0. Further, when the deterioration degree difference ΔDL is a predetermined value or more D _5, the value of the more correction coefficient K ₅ deterioration degree difference ΔDL increases is set to a value smaller than 1.0.

As a method for compensating the electric output assist amount Q _ASST , one of the following two methods is selected according to the operating state of the fuel cell 3.
The first compensation method is selected when the fuel cell 3 is being activated. The charge / discharge output calculation unit 17 _increases the electric output of the fuel cell 3 in order to compensate the electric output of the electric output assist amount Q _{ASST in} the fuel cell 3. The fuel cell 3 is being activated when the rechargeable battery is being charged or when the fuel cell 3 is in a power generation idle state to be described later.

The second compensation method is selected while the fuel cell 3 is stopped. The fuel cell 3 is stopped when the charging of the rechargeable battery has already been completed. Therefore, in this case, the charge / discharge output calculation unit 17 temporarily changes the charge battery to a discharge target in order to supplement the charge output of the electric output assist amount Q _ASST with the charge battery that has been fully charged. Assist.

First, the first compensation method will be described in detail. When the added value (Q + Q _ASST ) of the charging output Q and the electric output assist amount Q _ASST is less than the maximum electric output Q _{FC_MAX} of the fuel cell 3, the added value (Q + Q _ASST ) is used as the actual value of the fuel cell 3. Power generation output of Q _TGT . That is, all of the electric output assist amount Q _ASST is compensated by the electric output from the fuel cell 3 while maintaining the charging output Q.

On the other hand, when the added value (Q + Q _ASST ) is _{equal to} or greater than the maximum electric output Q _{FC_MAX} of the fuel cell 3, the maximum electric output Q _{FC_MAX} is _set as the actual power generation output Q _TGT of the fuel cell 3. Here, the electrical output assist amount Q _ASST is the case of less than the maximum electrical output Q _{FC_MAX,} together with all electrical output assist amount Q _ASST is compensated by electrical output from the fuel cell 3, charge output Q is decreased. If the electric output assist amount Q _ASST exceeds the maximum electric output Q _{FC_MAX} , all of the electric output from the fuel cell 3 is supplied to the motor 4 side, but a part of the electric output assist amount Q _ASST Is compensated by the electric output from the fuel cell 3. At this time, the charging output Q supplied from the fuel cell 3 to the charging battery is zero.

  The charging input C of the charging battery basically has a magnitude corresponding to the charging output Q of the fuel cell 3. That is, the charging state is controlled such that the charging input C increases when the small deterioration battery is charged and the charging input C decreases when the large deterioration battery is charged. Therefore, if it is assumed that the charging capacity is constant, the charging of the small deteriorated battery is completed earlier than the large deteriorated battery.

Further, when the fuel cell 3 compensates for the electrical output assist amount Q _ASST corresponding to the shortage of the electrical output of the discharge cell, the required electrical output Q _M of the motor 4 and the electrical output assist amount Q _{ASST of} the fuel cell 3, The charging input C changes according to the maximum electrical output Q _{FC_MAX} . For example, when the added value (Q + Q _ASST ) of the charge output Q and the electric output assist amount Q _ASST is _{equal to} or greater than the maximum electric output Q _{FC_MAX} of the fuel cell 3, the charge input C is smaller than the charge output Q. In this case, the maximum electrical output Q _{FC_MAX} is greater than the electrical output assist amount Q _ASST, minus the electric output assist amount Q _ASST corresponds to the charging input C from the maximum electrical output Q _{FC_MAX.} If the maximum electrical output Q _{FC_MAX} is less than or equal to the electrical output assist amount Q _ASST, all of the charge output Q of the fuel cell 3 is consumed by the motor 4 and the charge input C becomes zero.

The discharge output D of the discharge battery basically has a magnitude corresponding to the required electrical output Q _M of the motor 4. On the other hand, since the maximum value of the discharge output D is the maximum electrical output Q _MAX , when the required electrical output Q _M exceeds the maximum electrical output Q _MAX , the discharge output D is set equal to the maximum electrical output Q _MAX. The discharge state is controlled, and the fuel cell 3 bears the insufficient electrical output. Further, since the maximum electrical output Q _MAX of the secondary battery 2 is calculated based on the deterioration degree DL and the deterioration degree difference ΔDL of the discharge battery, the maximum value of the discharge output D decreases as the deterioration progresses. The electric output is suppressed. If the maximum electrical output Q _{FC_MAX} of the fuel cell 3 can cover all of the required electrical output Q _M of the motor 4, the discharge output D may be zero.

On the other hand, in the second compensation method, instead of the fuel cell 3 in the first compensation method, the charged battery that has been charged bears the assist power. The charge / discharge output calculation unit 17 causes the rechargeable battery that has been charged to transition to a state in which it can be discharged temporarily. The secondary battery 2 placed in such a state is called a temporary discharge battery.
When the electric output assist amount Q _ASST is less than the maximum electric output E _MAX of the temporary discharge battery, the electric output assist amount Q _ASST is _set as the discharge output E of the temporary discharge battery. That is, all of the electric output assist amount Q _ASST is compensated by the electric output from the temporary discharge battery. On the other hand, when the electrical output assist amount Q _ASST is greater than or _equal to the maximum electrical output E _MAX , the maximum electrical output E _MAX is set as the discharge output E of the temporary discharge battery. In this case, all of the electric output from the provisional discharge battery is supplied to the motor 4 side, but the electric output _covers a part of the electric output assist amount Q _ASST .

Regardless of the magnitude relationship between the electrical output assist amount Q _ASST and the maximum electrical output E _MAX , the maximum electrical output E _MAX may be set to the discharge output E of the provisional discharge battery. In this case, the discharge output D of the discharge battery becomes smaller than the maximum electrical output Q _{MAX as} the maximum electrical output E _MAX is larger than the electrical output assist amount Q _ASST . Therefore, the discharge load of the discharge battery is reduced, and the progress of deterioration is further suppressed.
It is also conceivable to set the added value (Q _ASST + Q _MAX ) of the electrical output assist amount Q _ASST and the maximum electrical output Q _MAX of the discharge battery as the discharge output E of the temporary discharge battery. In this case, the discharge output D of the discharge battery becomes zero, and the main body that substantially drives the motor 4 is only the temporary discharge battery.

[D. Switching judgment part]
The switching determination unit 18 (change determination unit) performs determination related to switching between the charging battery and the discharging battery. Here, it is determined whether or not the aforementioned switching condition is satisfied based on the relative deterioration degree DL, and each of the charging battery and the discharging battery is changed when the switching condition is satisfied. As the switching condition, a first switching condition regarding the charging rate SOC of the discharge battery and a second switching condition regarding the charging rate SOC of the charging battery are set. The switching determination unit 18 includes a first changing unit 18a (first changing unit) that switches the discharge target based on the first switching condition, and a second change that switches the discharge target based on the second switching condition. A portion 18b (second changing means) is provided.

The first switching condition is that the charging rate SOC of the discharge battery is equal to or lower than the lower limit charging rate SOC _{MIN_DIS} . That is, when the discharge cell is no longer able to meet the demand electrical output Q _M of the motor 4, the role of the charge and discharge are switched by the first changing unit 18a. This first switching condition prevents the secondary battery 2 from being depleted.
The second switching condition is that the charging rate SOC of the rechargeable battery is _{equal to} or higher than the upper limit charging rate SOC _{MAX_CHA} , and the relative deterioration degree DL and deterioration degree difference ΔDL of the secondary battery 2 satisfy the predetermined deterioration degree condition. That is. The second changing unit 18b changes the role of charging / discharging based on the relative deterioration degree DL and the deterioration degree difference ΔDL of the secondary battery 2 when the charging battery is in a fully charged state where no further charging is possible.

The second changing unit 18b of the present embodiment determines that “the charged battery is relatively deteriorated rather than the discharged battery” as the predetermined deterioration degree condition. That is, when the fully charged rechargeable battery is a small deterioration battery and the discharge battery is a large deterioration battery, it is determined that the predetermined deterioration degree condition is satisfied. Therefore, the second changing unit 18b changes the role of charging / discharging when the charging rate SOC of the charging battery is _{equal to} or higher than the upper limit charging rate SOC _{MAX_CHA} and the discharge battery is a highly deteriorated battery. Conversely, even if the charge rate SOC of the rechargeable battery is _{equal to} or higher than the upper limit charge rate SOC _{MAX_CHA} , if the rechargeable battery is a _highly deteriorated battery, the discharge battery is discharged without changing the role of charge / discharge. to continue. In this case, the operation of the fuel cell 3 is stopped, and the rechargeable battery that is a large deterioration battery is maintained in a fully charged state.

Note that the determination of the first change unit 18a is prioritized over the determination of the second change unit 18b so that the power of the discharge battery is not depleted before the rechargeable battery is fully charged. Therefore, if the charge rate SOC of the discharge battery _falls below the lower limit charge rate SOC _{MIN_DIS} before the charge rate SOC of the rechargeable battery reaches its upper limit charge rate SOC _{MAX_CHA} , the charge / discharge is performed regardless of whether or not the deterioration condition is met. The role of is changed.

[E. Charging suspension determination unit]
The charging suspension determination unit 19 (pause control means) performs a determination for stopping charging by the fuel cell 3 during normal traveling. Here, when a predetermined charging suspension condition is satisfied, charging of the rechargeable battery is temporarily prohibited, and the fuel cell 3 is controlled to the power generation idle state. The power generation idle state is a state where the fuel cell 3 stops power generation while receiving fuel supply or supplies a minimum power. For example, the state in which the switch interposed on the DC circuit between the electrode of the fuel cell 3 and the converter 6 is disconnected, the state in which the fuel supply is performed in the intermittent mode or the low voltage power generation mode, etc. Included in the idle state.
In this embodiment, when the charge rate SOC of the discharge battery is equal to or higher than the pause determination charge rate SOC _PAUSE and the battery temperature T of the charge battery is equal to or higher than the pause temperature T _PAUSE , charging is paused and the fuel cell 3 generates power. Idle state is maintained. When the above condition is not satisfied, power generation in the fuel cell 3 is resumed and the rechargeable battery is charged.

The suspension determination charging rate SOC _PAUSE is set according to the deterioration level difference ΔDL of the secondary battery 2 calculated by the deterioration level determination unit 11. The charge pause determination unit 19 sets a correction coefficient K ₆ based on the deterioration degree difference ΔDL, and determines the discharge battery pause determination by multiplying the correction coefficient K ₆ by the standard pause charge rate SOC _CBASE as shown in Equation 7. Calculate as charge rate SOC _PAUSE . In addition, since there is a possibility that the role of charging / discharging may be switched during charging pause, it is preferable to set the standard pause charging rate SOC _CBASE to a relatively high value, for example, a value within a range of 70 to 80%. It is said.
SOC _PAUSE = K ₆ × SOC _CBASE … Formula 7

Correction factor K ₆ is better when higher than at low deterioration degree DL discharge cell, a coefficient for such charge is less likely to pause. For example, as shown in FIG. 5 (f), when the deterioration degree difference ΔDL is less than a predetermined value D ₆ , the deterioration degree DL is considered to be substantially equal, and the value of the correction coefficient K ₆ is set to 1.0. Further, when the deterioration degree difference ΔDL is a predetermined value or more D _6, the value of the more correction coefficient K ₆ deterioration degree difference ΔDL increases is set to a value greater than 1.0.

Also, the pause temperature T _PAUSE is set to a magnitude corresponding to the deterioration degree difference ΔDL. The charging suspension determination unit 19 sets the correction coefficient K ₇ based on the deterioration degree difference ΔDL, and, as shown in Equation 8, the charging battery suspension temperature _obtained by multiplying the correction coefficient K ₇ by the standard suspension temperature T _CBASE Calculated as T _PAUSE .
T _PAUSE = K ₇ × T _CBASE … Formula 8

The correction factor K ₇ are towards the high charging battery degradation degree as compared with the low degradation degree rechargeable battery is a coefficient for the to rest at a lower temperature. For example, as shown in FIG. 5 (g), when the deterioration degree difference ΔDL is less than a predetermined value D _7, the value of the correction coefficient K ₇ is regarded as deterioration degree DL is substantially equal is set to 1.0. When the deterioration degree difference ΔDL is equal to or greater than the predetermined value D ₇ , the correction coefficient K ₇ is set to a value smaller than 1.0 as the deterioration degree difference ΔDL increases.

The predetermined values D _{1 to} D ₇ related to the setting of the correction coefficients K _{1 to} K ₇ may be the same value, or may be set to different values. For example, when the correction coefficient K ₁ is set, the predetermined value D ₁ can be made as large as possible (larger than the other predetermined values D _{2 to} D ₇ ) in order to secure the capacity of the secondary battery 2 during external charging. Conceivable. On the other hand, in order to suppress deterioration of the secondary battery 2 due to external charging, it is conceivable to make the predetermined value D ₁ as small as possible (smaller than the other predetermined values D _{2 to} D ₇ ). As described above, specific values of the predetermined values D _{1 to} D ₇ may be set as appropriate according to the performance and characteristics required for the power control apparatus 1.

[5. flowchart]
6 to 10 are flowcharts illustrating control procedures performed by the electronic control device 10. FIG. 6 is a flow for setting a control flag corresponding to the state of the secondary battery 2. FIG. 7 is a flowchart for calculating various parameters for controlling the charge / discharge state during normal running, and FIG. 8 controls the electrical output of the fuel cell 3 and the charge / discharge output of the secondary battery 2 during normal running. It is a flow to do. FIG. 9 is a flow for performing determination for switching the role of charging / discharging of the secondary battery 2 during normal traveling, and FIG. 10 is a flow for controlling the state of charge during external charging. These flows are repeatedly executed at a predetermined cycle inside the electronic control device 10.

[5-1. Flag setting]
In the flag setting flow shown in FIG. 6, control flags F _LC and F _LDC related to the deterioration degree and charge / discharge state of the secondary battery 2 are set. The flag F _LC is set to F _LC = 1 (on) when the secondary battery 2 to be charged during normal driving is classified as a _highly deteriorated battery, and F _LC = It is set to 0 (off). The flag F _LDC is set to F _LDC = 1 (on) when the secondary battery 2 to be discharged during normal driving is classified as a _highly deteriorated battery, and F when the discharge object is not a highly deteriorated battery. _LDC = 0 (off) is set.

  In step A10, the target setting unit 12 sets a discharge battery and a rechargeable battery during normal travel. When the number of secondary batteries 2 is two, either one is a discharge battery and the other is a rechargeable battery. In step A20, the deterioration degree DL of each of the first battery 2a and the second battery 2b is read into the deterioration degree determination unit 11, and in step A30, the absolute value of the difference between the deterioration degrees DL of the two secondary batteries 2 is obtained. Calculated as a deterioration degree difference ΔDL.

In step A40, the deterioration degree determination unit 11, the deterioration degree difference ΔDL whether exceeds a predetermined value D ₀ is determined. Here, when ΔDL ≦ D ₀ , it is determined that the deterioration state is uniform, the process proceeds to step A70, and the values of the flags F _LC and F _LDC are both set to 0. When ΔDL> D ₀ , it is determined that one with a large deterioration degree DL is a highly deteriorated battery, and one with a small deterioration degree DL is determined to be a small deterioration battery, and the process proceeds to step A50.

In step A50, it is determined based on the setting in step A10 whether or not the highly deteriorated battery is a rechargeable battery. During establishment of this condition proceeds to step A80, together with the value of the flag F _LC is set to 1, the value of the flag F _LDC is set to 0. When the highly deteriorated battery is not a rechargeable battery in step A50, the process proceeds to step A60.

In Step A60, it is determined whether or not the highly deteriorated battery is a discharge battery. During establishment of this condition proceeds to step A90, together with the value of the flag F _LC is set to 0, the value of the flag F _LDC is set to 1. If the number of secondary batteries 2 is three or more and the highly deteriorated battery is neither a charge battery nor a discharge battery, the process proceeds to step A70. When the flag is set in any of steps A70, A80, and A90, the process proceeds to step A100.

  In step A100, the external charge control unit 13 determines whether or not an external charge start condition is satisfied. For example, when insertion of the charging cable into the inlet 21 is detected and power is supplied from the external power source to the in-vehicle charger 8, it is determined that the external charging start condition is satisfied, and the process proceeds to the external charging flow shown in FIG. On the other hand, when the external charge start condition is not satisfied, the process proceeds to a parameter calculation flow related to charge / discharge control during normal traveling shown in FIG.

[5-2. Parameter calculation]
In the parameter calculation flow shown in FIG. 7, the charge / discharge control unit 14 calculates parameters used for charge / discharge control during normal traveling. Value of the step B10 in the flag F _LC is determined, if F _LC = 1 the process proceeds to step B30～B35, the flow proceeds to step B20 if F _LC = 0. In step B20, the value of the flag F _LDC is determined. If F _LDC = 1, the process proceeds to steps B40 to B45. If F _LDC = 0, the process proceeds to step B50.
Step B30~B35, B40~45 is a step for setting the correction coefficient K ₂ ~K _7.

The correction factor K ₂ is a coefficient for reducing corrects the upper limit charging rate SOC _{MAX_CHA} when large deterioration battery is rechargeable battery. Accordingly, in step B30, for example, based on the map shown in FIG. 5 (b), the correction factor K ₂ is set. The value of the correction factor K ₂ is set within a range of 1.0 or less, the smaller the deterioration degree difference ΔDL increases. On the other hand, the value of the correction factor K ₂ in step B40 is the K ₂ = 1.0.

The correction factor K ₃ is a factor for increasing correction of the lower limit charging rate SOC _{MIN_DIS} when large deterioration battery is discharged batteries. Therefore, in step B31, the value of the correction coefficient K ₃ is set to K ₃ = 1.0. On the other hand, in step B41, for example, based on the map shown in FIG. 5 (c), the correction factor K ₃ is set. The value of the correction coefficient K ₃ is set within a range of 1.0 or more, the larger the deterioration degree difference ΔDL increases.

Correction coefficient K _4, when a large deterioration battery is discharged the battery (i.e., when the small deterioration battery is rechargeable battery) is a coefficient for increasing correcting the charge output Q of the fuel cell 3. Therefore, the value of the correction coefficient K ₄ at step B32 is the K ₄ = 1.0. On the other hand, in step B42, for example, based on the map shown in FIG. 5 (d), the correction coefficient K ₄ is set. The value of the correction coefficient K ₄ is set within a range of 1.0 or more, the larger the deterioration degree difference ΔDL increases.

The correction factor K ₅ is a factor for reducing correction the maximum electrical output Q _MAX large deterioration battery is the maximum value of the discharge power D when a discharge cell. Accordingly, in step B33, the value of the correction coefficient K ₅ is set to K ₅ = 1.0. On the other hand, in step B43, for example, based on the map shown in FIG. 5 (e), the correction coefficient K ₅ are set. The value of the correction coefficient K ₅ is set within a range of 1.0 or less, the smaller the deterioration degree difference ΔDL increases.

The correction coefficient K ₆ is a coefficient for increasing and correcting the suspension determination charging rate SOC _PAUSE used for determining the condition of the suspension of charging during discharging of the highly deteriorated battery. Accordingly, in step B34, the value of the correction coefficient K ₆ is set to K ₆ = 1.0. On the other hand, in step B44, for example, based on the map shown in FIG. 5 (f), the correction coefficient K ₆ is set. The value of the correction coefficient K ₆ is set within a range of 1.0 or more, the larger the deterioration degree difference ΔDL increases.

The correction coefficient K ₇ is a coefficient for decreasing and correcting the pause temperature T _PAUSE used for determining the charge pause condition during charging of the highly deteriorated battery. Accordingly, in step B35, for example, based on the map shown in FIG. 5 (g), the correction coefficient K ₇ is set. The value of the correction coefficient K ₇ is set within a range of 1.0 or less, the smaller the deterioration degree difference ΔDL increases. On the other hand, the value of the correction coefficient K ₇ at step B45 is the K ₇ = 1.0.
The charging battery, both of the discharge cell when not greater degradation battery, in step B50, the value of all the correction factor K ₂ ~K ₇ is set to 1.0.

In step B60, the charging rates SOC of the charging battery and the discharging battery are calculated, and in step B70, the charging rate decrease rate X of the discharging battery is calculated. In step B80, the basic electrical output calculator 15 calculates the basic electrical output Q _FC of the fuel cell 3 from the charge rate decrease rate X of the discharge battery and the charge rate SOC of the charge battery based on the map as shown in FIG. Is calculated.

In step B90, the charge and discharge region computing unit 16, the correction factor K ₂ multiplied by the standard upper limit charge rate SOC _SFCBASE is calculated as an upper limit charging rate SOC _{MAX_CHA} charging the battery. The upper limit charging rate SOC _{MAX_CHA} corresponds to the charging rate SOC when charging of the rechargeable battery is completed, and is used to determine the timing for switching the role of charging / discharging in the flow shown in FIG.

In step B100, the charge and discharge region computing unit 16, the correction coefficient K ₃ multiplied by the standard limit storage rate SOC _LWBASE is calculated as a lower limit charging rate SOC _{MIN_DIS} discharge cell. The lower limit charge rate SOC _{MIN_DIS} corresponds to the charge rate SOC as the lower limit of discharge of the discharge battery. Similarly to the upper limit charging rate SOC _{MAX_CHA} , it is used to determine the timing for switching the role of charging / discharging in the flow shown in FIG.

In step B 110, multiplied by the basic electrical output Q _FC to the correction coefficient K ₄ is calculated as the charge output Q. The charging output Q is an electrical output of the fuel cell 3, and this power is supplied to the charging battery if there is no shortage of power supplied to the motor 4.
In step B 120, multiplied by the standard maximum electrical output Q _MAXBASE the correction coefficient K ₅ is calculated as the maximum electric output Q _MAX. The maximum electrical output Q _MAX is the maximum value of the discharge output D of the discharge battery. When the required electric output Q _M of the motor 4 exceeds the maximum electric output Q _MAX , the insufficient electric output is replenished from the fuel cell 3.

In step B 130, multiplied by the standard pause charging rate SOC _CBASE the correction coefficient K ₆ is calculated as resting determining the charging rate SOC _PAUSE charging the battery. In step B 140, multiplied by the standard resting temperature T _CBASE the correction coefficient K ₇ is calculated as resting temperature T _PAUSE charging the battery. The pause determination charging rate SOC _PAUSE and the pause temperature T _PAUSE are used to determine whether or not charging of the rechargeable battery may be temporarily paused.
When the calculation of the above parameters is completed, the flow proceeds to the charge / discharge control flow during normal travel shown in FIG.

[5-3. Charge / discharge control]
In the flow shown in FIG. 8, the charge / discharge control unit 14 controls the magnitudes of the electrical outputs of the secondary battery 2 and the fuel cell 3. In step C <b> 10, the required electric output Q _M of the motor 4 is read into the electronic control device 10. In step C20, the value of the flag F _LDC is determined. If F _LDC = 1, the process proceeds to step C30, and if F _LDC = 0, the process proceeds to step C130.

Step C30 is a step performed when the highly deteriorated battery is a discharge battery. In step C30, whether or not required electrical output Q _M of the motor 4 exceeds the maximum electrical output Q _MAX of the discharge cell is determined. Here, when Q _M > Q _MAX , the process proceeds to step C40, and when Q _M ≤Q _MAX , the process proceeds to step C130.

In step C40, the charge / discharge output calculation unit 17 calculates the electric output assist amount Q _ASST by multiplying the value obtained by subtracting the maximum electric output Q _MAX from the required electric output Q _M by the correction coefficient L. The electric output assist amount Q _ASST is an electric output corresponding to a shortage of the discharge output D with respect to the required electric output Q _M of the motor 4. In the subsequent step C50, it is determined whether or not the fuel cell 3 is being started. If the fuel cell 3 is being started, the process proceeds to step C60, and if it is stopped, the process proceeds to step C110. The start-up here includes a state where the fuel cell 3 is generating power (a state where the rechargeable battery is charged) and a power generation idle state.

In step C60, in order to confirm whether or not the fuel cell 3 has sufficient electric output capability to assist the discharge cell, an addition value (Q + Q _ASST ) of the charge output Q and the electric output assist amount Q _{ASST. Is} less than the maximum electrical output Q _{FC_MAX} of the fuel cell 3. Here, when Q _{FC_MAX} > (Q + Q _ASST ), it is _determined that the _remaining capacity of the fuel cell 3 is sufficient, and the process proceeds to Step C70. On the other hand, when Q _{FC_MAX} ≦ (Q + Q _ASST ), the process proceeds to Step C90.

In step C70, the added value (Q + Q _ASST ) of the charging output Q and the electrical output assist amount Q _ASST is controlled as the actual power generation output Q _TGT of the fuel cell 3. In step C80, the discharge cell is controlled so that the discharge output D becomes the maximum electrical output Q _MAX. Thereby, the charge input C supplied to the rechargeable battery corresponds to the charge output Q calculated by the charge / discharge output calculation unit 17.

In step C90, the electric output of the fuel cell 3 is controlled to be the maximum electric output Q _{FC_MAX} . In step C100, the discharge cell is controlled so that the discharge output D becomes the maximum electrical output Q _MAX. At this time, the charge input C supplied to the rechargeable battery corresponds to a value _obtained by subtracting the electric output assist amount Q _ASST from the maximum electric output Q _{FC_MAX} and is a value smaller than the charge output Q.

In Step C110, since the fuel cell 3 is stopped, the charged battery that has been charged is temporarily changed to a dischargeable state to become a temporary discharge battery, and the discharge output E corresponding to the electrical output assist amount Q _ASST is set. It is supplied to the motor 4 from the temporary discharge battery. In step C120, the discharge output D of the discharge cell is controlled so as to maximize the electrical output Q _MAX. Instead of performing the control in step C110, the control configuration may be such that the process proceeds to step D70 in the flowchart of FIG. 9 to be described later, and the roles of the charging battery and the discharging battery are switched.

Step C130 is a step that is performed when the discharge target is not a highly deteriorated battery (F _LDC = 0), or when the required electrical output Q _M of the motor 4 is equal to or less than the maximum electrical output Q _{MAX of the} discharge battery. Here, similarly to step C50, it is determined whether or not the fuel cell 3 is being activated. If the fuel cell 3 is being activated, the process proceeds to step C140, and if it is stopped, the process proceeds to step C160.

In step C140, the charging output Q is controlled as the actual power generation output Q _TGT of the fuel cell 3. In step C150, the discharge output D the discharge cell is controlled such that the required electrical output Q _M of the motor 4. Thereby, the charge input C supplied to the rechargeable battery corresponds to the charge output Q of the fuel cell 3.

In step C160, charging by the fuel cell 3 has not been performed (that is, charging has already been completed or the engine is in a power generation idle state), so that the discharge output D becomes the required output Q _{M of the} motor 4. The discharge battery is controlled. After Steps C80, C100, C120, C150, and C160 are performed, the process proceeds to the switching determination flow shown in FIG.

[5-4. Switching judgment]
In the switching determination flow shown in FIG. 9, the timing for switching the charging / discharging role of the secondary battery 2 and the resting state of the charging battery (the power generation idle state of the fuel cell 3) are controlled. The flag G used in this flow is for grasping the charge / discharge state after external charging. After the external charging is completed, G = 1 is set until all the highly deteriorated batteries are used as discharge batteries at least once. After all highly deteriorated batteries have been used as discharge batteries at least once, G = 0 is set until the next external charging is completed.

In Step D10, the charging suspension determination unit 19 determines whether or not the battery temperature T of the charging battery is lower than the suspension temperature T _PAUSE . Here, when T <T _PAUSE , since the charging suspension condition is not satisfied, the process proceeds to Step D50. On the other hand, when T ≧ T _PAUSE , the process proceeds to step D20 for determining another charging suspension condition.

In step D20, the charging suspension determination unit 19 determines whether or not the charging rate SOC of the discharge battery is equal to or higher than the suspension determination charging rate SOC _PAUSE . Here, when the charging rate SOC <SOC _PAUSE , the charging suspension condition is not satisfied, so the routine proceeds to step D50. On the other hand, when the charging rate SOC ≧ SOC _PAUSE , the charging suspension condition is satisfied, and the process proceeds to Step D30.
In step D30, the fuel cell 3 is controlled to the power generation idle state, and power generation is temporarily stopped. In the subsequent step D40, power supply from the discharge battery is continued. Subsequent control proceeds to the flag setting flow of FIG.

In step D50 that proceeds when the charging suspension condition is not satisfied, the switching determination unit 18 determines the first switching condition. Here, it is determined whether or not the charging rate SOC of the discharge battery is equal to or lower than the lower limit charging rate SOC _{MIN_DIS} . Here, when the charging rate SOC ≦ SOC _{MIN_DIS} , the process proceeds to step D60, and when the charging rate SOC> SOC _{MIN_DIS} , the process proceeds to step D100.

  In step D60, charging of the rechargeable battery and discharging from the discharge battery are completed, and the role of charge / discharge is switched in subsequent step D70. When the number of secondary batteries 2 is two, the rechargeable battery so far becomes a new discharge battery, and the previous discharge battery becomes a new rechargeable battery. When the number of secondary batteries 2 is three or more, new discharge batteries and rechargeable batteries are selected according to a predetermined selection order.

  In Step D80, when there is the secondary battery 2 corresponding to the highly deteriorated battery, it is determined whether or not all the highly deteriorated batteries have played the role of the discharge battery at least once. When this condition is satisfied, the process proceeds to step D90, the value of the flag G is set to G = 0, and then the process proceeds to the flag setting flow shown in FIG.

When the process proceeds from step D50 to step D100, the switching determination unit 18 determines the second switching condition. Here, it is determined whether or not the charging rate SOC of the rechargeable battery is _{equal to} or higher than the upper limit charging rate SOC _{MAX_CHA} . Here, when the charging rate SOC ≧ SOC _{MAX_CHA} , the process proceeds to step D110, and when the charging rate SOC <SOC _{MAX_CHA} , the process proceeds to step D150. In step D150, charging / discharging in each secondary battery 2 is continued, and the flow proceeds to the flag setting flow in FIG.

At step D110, the value of the flag F _LDC is whether F _LDC = 1 is determined. When F _LDC = 1, the process proceeds to step D120, and when F _LDC = 0, the process proceeds to step D130. In Step D120, it is determined whether or not the value of the flag G is G = 0. If G = 0, the process proceeds to step D60. For example, when charging of the small deterioration battery is completed when the large deterioration battery is a discharge battery, the process proceeds to step D60 and the charge / discharge roles are switched.

  On the other hand, if G = 1 in step D120, the process proceeds to step D130. In step D130, charging of the rechargeable battery is completed, and in subsequent step D140, only discharging from the discharge battery is continued. These steps correspond to a state in which the rechargeable battery is fully charged and the fuel cell 3 has stopped operating. Subsequent control proceeds to the flag setting flow of FIG.

[5-5. External charging]
In the external charging flow shown in FIG. 10, the charging state of the secondary battery 2 during external charging is controlled. In step E10, it is determined whether or not the value of either the flag _FLC or _FLDC is 1. That is, it is determined whether or not there is a highly deteriorated battery in the secondary battery 2. Here, when F _LC = 1 or F _LDC = 1, the process proceeds to step E20. Otherwise, the process proceeds to step E40.

At step E20, the correction factor K ₁ in the external charging control unit 13 is set. The correction factor K ₁ is a coefficient for reducing corrected external charging time upper limit charge rate SOC _{MAX_EX} for terminating the charging of the large deterioration battery during external charging. Therefore, in step E20, for example, based on the map shown in FIG. 5 (a), the correction factor K ₁ is set. The value of the correction coefficient K ₁ is set within a range of 1.0 or less, the smaller the deterioration degree difference ΔDL increases.

At step E30, the external charging control unit 13, multiplied by the external charging during a typical upper limit charge rate SOC _HPIBASE the correction factor K ₁ is calculated as the external charging when the upper limit charging rate SOC _{MAX_EX} large deterioration battery. In step E40, the external charging upper limit charge rate SOC _{MAX_EX} for the secondary batteries 2 other than those set in step E30 is set to the same value as the external charge standard upper limit charge rate SOC _HPIBASE . Therefore, upper limit charging rate SOC _{MAX_EX} at the time of external charging of secondary battery 2 that is relatively deteriorated is smaller than that of secondary battery 2 that is not deteriorated, according to the degree of deterioration DL.

In step E50, each charging rate SOC is calculated based on the current value or voltage value given to each secondary battery 2. Further, in step E60, it is determined whether or not the individual charge rate SOC exceeds the external charge upper limit charge rate SOC _{MAX_EX} for all the secondary batteries 2. If this condition is not satisfied, the process proceeds to step E90, and external charging is continued. When there is a difference between the charge rate SOC of each secondary battery 2 and the external charge upper limit charge rate SOC _{MAX_EX} , external charge is terminated in order from the one where the charge rate SOC has reached the external charge upper limit charge rate SOC _{MAX_EX.} External charging of the secondary battery 2 is continued.

On the other hand, when the charging rate SOC of all the secondary batteries 2 reaches the respective external charging upper limit charging rate SOC _{MAX_EX} , the process proceeds to step E70, and the external charging is finished.
In the subsequent step E80, the value of the flag G used in the switching determination flow of FIG. Subsequent control proceeds to the flag setting flow of FIG.

[6. Action]
[6-1. Charging / discharging area graph]
FIG. 11A shows the secular change of the deterioration degree DL of the first battery 2a and the second battery 2b. The broken line in the figure is a graph of the deterioration degree DL ₁ of the first battery 2a, and the solid line is a graph of the deterioration degree DL ₂ of the second battery 2b. Here, it is assumed that the deterioration progressing speed of the second battery 2b is slightly faster than the deterioration progressing speed of the first battery 2a.

During the period from the start of use of the secondary battery 2 to the time t ₀ , both the first battery 2a and the second battery 2b are gradually deteriorated, and the deterioration degree difference ΔDL is equal to or less than a predetermined value D ₀ . Therefore, the upper limit charge rate SOC _MAX of the first cell 2a, each of the lower limit charging rate SOC _MIN is set upper limit charge rate SOC _MAX of the second battery 2b, identical to the lower charging rate SOC _MIN, the charge-discharge region are matched.

When the deterioration degree difference ΔDL exceeds the predetermined value D ₀ at time t ₀ , the second battery 2b having a large deterioration degree DL is classified as a large deterioration battery, and the first battery 2a is classified as a small deterioration battery. Accordingly, the value of the upper limit charging rate SOC _MAX of the second battery 2b is set lower than the value of the upper limit charging rate SOC _MAX of the first battery 2a both during external charging and during normal driving. The Further, the value of the lower limit charge rate SOC _MIN of the second battery 2b is set higher than the value of the lower limit charge rate SOC _MIN of the first battery 2a.

By this setting, as shown in FIG. 11 (b), the charge and discharge zone of the second cell 2b at time t ₀ after becomes narrower than the time t ₀ before the charging rate SOC of the secondary battery 2b Repeatedly increases and decreases within a narrower range than the first battery 2a. Accordingly, the electrical load applied to the second battery 2b due to overcharge or deep discharge is reduced, and the progress of deterioration is suppressed.

  Moreover, since the charging / discharging area | region of the charging rate SOC of the 2nd battery 2b becomes narrow, possibility that the charging rate SOC will be put in a high state for a long time becomes small, for example. Similarly, the possibility that the charging rate SOC is left in an excessively lowered state is also reduced. On the other hand, the secondary battery 2 in a no-load state has a characteristic that deterioration does not easily progress when the charging rate SOC is in a moderate state (for example, around 50%) that is neither too much nor too little. Therefore, the second battery 2b is less likely to deteriorate than the first battery 2a, and the decreasing slope of the deterioration degree DL of the second battery 2b gradually becomes gentle as shown in FIG.

On the other hand, the degree of deterioration DL of the first battery 2a decreases slightly after the second battery 2b, and the broken line graph gradually approaches the solid line graph. When the deterioration degree DL of the first battery 2a decreases until the deterioration degree difference ΔDL becomes equal to or less than the predetermined value D ₀ , the classification of the large deterioration battery and the small deterioration battery is returned to the blank page, and the same upper limit charge rate SOC _MAX and lower limit charge are the same. The rate SOC _MIN setting will be used.

By repeating such control, one of the deterioration degrees DL of the first battery 2a and the second battery 2b does not increase excessively. As shown in FIG. 11 (a), such as variations in the degradation degree DL of the first cell 2a and the second cell 2b is stabilized at a predetermined value D ₀ before and after, only one of the secondary battery 2 deteriorates significantly There is nothing. Further, even the number of the secondary battery 2 three or more, since the progression as the deterioration degree DL is large is suppressed, variations in each of the deterioration degree DL is converged substantially within a predetermined value D ₀ Degradation progresses evenly.

[6-2. Graph of charge / discharge cycle and charge rate]
Changes with time in the charging rate SOC of the first battery 2a and the second battery 2b are shown in FIGS. Here, the charge / discharge cycle in a state in which the first battery 2a is classified as a small deterioration battery and the second battery 2b is classified as a large deterioration battery will be described. Upper limit charge rate SOC _MAX and external charging when the upper limit charging rate SOC _{MAX_EX} second battery 2b is set lower than the upper limit charge rate SOC _MAX and external charging when the upper limit charging rate SOC _{MAX_EX} the first cell 2a. Further, the lower limit charge rate SOC _MIN of the second battery 2b is set higher than the lower limit charge rate SOC _MIN of the first battery 2a.

Time t ₁ prior state, the first battery 2a is discharged battery, the second battery 2b are charged battery. When the charge rate SOC of the first battery 2a of the discharge side at time t ₁ is less than or equal to the lower charging rate SOC _MIN, it is switched roles charged and discharged first switching condition is satisfied. At this time, the first battery 2a is a rechargeable battery and the second battery 2b is a discharge battery.

At the time t ₁ to time t ₂ interval (the interval t ₁ ~t _2), with discharge power D of the second battery 2b is supplied to the motor 4, the charge output Q of the fuel cell 3 is supplied to the first battery 2a The first battery 2a is charged. Since the charge / discharge area of the second battery 2b is set to be narrower than the charge / discharge area of the first battery 2a, the time during which the motor 4 can be driven by the discharge output D of the second battery 2b is shorter than that of the first battery 2a. Prone.

On the other hand, the charging output Q of the fuel cell 3 for charging the first battery 2a which is a small deterioration battery increases as the deterioration degree DL of the second battery 2b which is a large deterioration battery increases. Thus, the charging rate increase slope of the first battery 2a of the section t ₁ ~t ₂ becomes steeper than the charge rate increase slope of the time t ₁ before the second battery 2b, the charging time of the first cell 2a Shortened. Therefore, the charging rate SOC of the first battery 2a is restored to a high level relatively early.

The charging output Q of the fuel cell 3 is supplied to the first battery 2a in the section t ₁ ~t ₂ is increased or decreased controlled in accordance with the charging rate reduction speed X of the second battery 2b is the discharge target at that time . For example, as shown in FIG. 4, the basic electric output Q _FC is set higher in view of the fact that the larger the charging rate decrease rate X of the second battery 2 b is, the easier the power is consumed earlier. The magnitude of the charging output Q is optimized.
When the charge rate SOC of the second battery 2b at time t ₂ is less than or equal to the lower charging rate SOC _MIN, it is switched roles charged and discharged first switching condition is satisfied. At this time, the first battery 2a becomes a discharge battery, and the second battery 2b becomes a rechargeable battery.

In the interval t _{2 to} t ₃ , the discharge output D of the first battery 2a is supplied to the motor 4, the charge output Q of the fuel cell 3 is supplied to the second battery 2b, and the second battery 2b is charged. Since the charge / discharge area of the first battery 2a is set wider than the charge / discharge area of the second battery 2b, the time during which the motor 4 can be driven by the discharge output D of the first battery 2a is relatively long.

In addition, the charging output Q of the fuel cell 3 for charging the second battery 2b, which is a highly deteriorated battery, is set smaller than when charging the first battery 2a, which is a small deteriorated battery. Thus, the charging rate increase slope of the second battery 2b in the interval t ₂ ~t ₃ becomes a low-gradient than the charge rate increase slope of the first battery 2a of the section t ₁ ~t _2, for the second cell 2b The charging load is reduced. Therefore, the progress of deterioration of the second battery 2b is suppressed.

When the charge rate SOC of the second battery 2b is greater than or equal to the upper rate SOC _MAX at time t _3, the charging of the second battery 2b is completed, the fuel cell 3 is stopped. At this time, since the charging rate SOC of the first battery 2a is not yet lower than the lower limit charging rate SOC _MIN , the first battery 2a continues to function as a discharge battery. Thereafter, the charging rate SOC of the first battery 2a is below the lower limit charging rate SOC _MIN at time t _4, is switched roles charged and discharged first switching condition is satisfied. The sections t _{3 to} t ₄ are no-load periods in which no electrical load acts on the second battery 2b. Therefore, the progress of the deterioration of the second battery 2b is further suppressed.

In section t ₄ ~t _5, similarly to the section t ₁ ~t _2, together with the discharge power D of the second battery 2b is supplied to the motor 4, the charge output Q of the fuel cell 3 is supplied to the first battery 2a The first battery 2a is charged. On the other hand, when the second battery 2b, which is a highly deteriorated battery, is a discharge battery, the role of charging / discharging is switched not only when the first switching condition but also when the second switching condition is satisfied.

For example, the charging rate SOC of the first battery 2a is greater than or equal to the upper rate SOC _MAX at time t _5, even if no if the charging rate SOC of the second battery 2b is equal to or less than a lower limit charge SOC _MIN, the charge and discharge The roles are switched, and the first battery 2a becomes a discharge battery. Therefore, the cumulative time for which the second battery 2b is used as a discharge battery is shorter than the cumulative time for which the first battery 2a is used as a discharge battery, and the progress of deterioration of the second battery 2b is suppressed.

At this time, since the second battery 2b becomes a rechargeable battery with a relatively high charge rate SOC, the subsequent charging time is shortened. When the charge rate SOC of the second battery 2b is greater than or equal to the upper rate SOC _MAX at time t _6, the charging of the second battery 2b is completed, the fuel cell 3 is stopped. Thus, the progress of deterioration of the second battery 2b is also suppressed by shortening the charging time.
Further, the interval t ₆ ~t ₇ is the same as no-load period of the second battery 2b and the interval t ₃ ~t _4. As the charging time is shortened, the no-load period is extended, and the progress of deterioration of the second battery 2b is suppressed.

Interval t ₇ ~t ₈ is a section in which external charging is performed. At the time of external charging, both the first battery 2a and the second battery 2b are charged. However, external charging when the upper limit charging rate SOC _{MAX_EX} second battery 2b is larger deterioration battery, to be set lower than the external charging when the upper limit charging rate SOC _{MAX_EX} the first cell 2a, is provided to the second battery 2b The electrical load is reduced and the progress of deterioration is suppressed. On the contrary, the first battery 2a is set to have a higher upper-limit charging rate SOC _{MAX_EX} during external charging than the second battery 2b, so that the charging capacity of the secondary battery 2 is sufficiently secured.

After the external charging is completed, the second battery 2b, which is a highly deteriorated battery, is used as a discharge battery with priority over the first battery 2a. In the interval t _{8 to} t ₉ , the discharge output D of the second battery 2 b is supplied to the motor 4. As a result, the time during which the charging rate SOC of the second battery 2b is high is shortened, and the progress of deterioration of the second battery 2b is suppressed. Moreover, since the charging rate SOC of the second battery 2b approaches a moderate state (for example, around 50%) that is neither too much nor too little, the progress of deterioration of the second battery 2b is more effectively suppressed.

[7. effect]
[7-1. Fuel cell output]
(1) In the power control device 1 described above, the basic electrical output Q _FC of the fuel cell 3 is calculated based on the charging rate decrease rate X of the secondary battery 2 on the discharge side. Thereby, the electric output control of the fuel cell 3 according to the discharge speed of each secondary battery 2 becomes possible, and the secondary battery 2 can be prevented from running out of electricity while suppressing the progress of deterioration of the fuel cell 3.
For example, in an operating state where the required electrical output Q _M of the motor 4 is small and the charging rate SOC of the secondary battery 2 on the discharge side slowly decreases, the basic electrical output Q _FC of the fuel cell 3 is set small. Thereby, the power generation load of the fuel cell 3 is reduced, and deterioration of the fuel cell 3 can be suppressed. Moreover, since the electrical output of the fuel cell 3 is relatively small, the power generation efficiency of the fuel cell 3 can be increased. Furthermore, the fuel efficiency related to driving of the fuel cell 3 can be improved by improving the power generation efficiency, and the running cost of the vehicle 20 can be reduced.

On the other hand, the basic electrical output Q _FC of the fuel cell 3 is set to be large in an operation state in which the required electrical output Q _M of the motor 4 is large and the charging rate SOC of the secondary battery 2 on the discharge side rapidly decreases. The secondary battery 2 on the charging side is charged relatively early. In this way, the electrical output of the fuel cell 3 can be controlled to increase or decrease in accordance with the power consumption rate, and the secondary battery 2 can be prevented from running out while suppressing the progress of deterioration of the fuel cell 3.

Note that the charging rate reduction rate X of the secondary battery 2 tends to increase as the deterioration progresses. Therefore, in the power control apparatus 1, the charging input C supplied to the small deterioration battery increases when the large deterioration battery is discharged, and the charging input C supplied to the large deterioration battery decreases when the small deterioration battery discharges. That is, the electrical output of the fuel cell 3 during charging to the relatively deteriorated secondary battery 2 is reduced, and accordingly, the deterioration of the secondary battery 2 on the charging side is suppressed.
Therefore, the deterioration state of the plurality of secondary batteries 2 can be equalized through the electric output control of the fuel cell 3. Thereby, the useful life of the secondary battery 2 can be extended and cost performance can be improved. For the secondary battery 2 on the relatively undegraded side, the electrical load acting on the secondary battery 2 can be reduced by reducing the electrical output of the fuel cell 3. The progress of deterioration can be suppressed.

(2) Further, in the power control apparatus 1 described above, the basic electrical output Q _FC of the fuel cell 3 is calculated based on not only the charging rate decrease rate X of the discharge battery but also the charging rate SOC of the charging battery.
For example, if a relatively high charging rate SOC of the rechargeable battery, since the electrostatic deleted without complete charging in a hurry do not occur, the basic electrical output Q _FC is set small. Thus, when there is a margin in the charging rate SOC with respect to the power consumption speed, the secondary battery 2 and the fuel can be prevented while making the secondary battery 2 short of electricity by setting the fuel cell 3 to a low output. Deterioration of the battery 3 can be suppressed.
In addition, if the charging rate SOC of the rechargeable battery is relatively low, the fuel cell 3 is set to a high output, so that the possibility of electric shortage can be reduced.

(3) Further, in the power control apparatus 1, as shown in FIG. 4, the lower the charging rate SOC of the secondary battery 2 on the charging side, or the lowering rate X of the charging rate of the secondary battery 2 on the discharging side. The larger the is, the higher the basic electrical output Q _FC of the fuel cell 3 is. As a result, it becomes possible to control the electric output of the fuel cell 3 in accordance with the charge / discharge states of both the secondary batteries 2 to be charged and discharged, and the power of the secondary battery 2 can be suppressed while the deterioration of the fuel cell 3 is suppressed. You can prevent shortage.
(4) Further, in the power control device 1, the charging rate SOC of the rechargeable battery than the charging rate decreases the rate X as shown in FIG. 4 is reflected strongly on the value of the basic electrical output Q _FC. In this way, by increasing the influence of the charging rate SOC on the charging side on the electrical output value of the fuel cell 3, it is possible to more reliably prevent the secondary battery 2 from being short of electricity and improve the reliability of the vehicle equipment. Can be made.

(5) Further, in the power control device 1 described above, the correction coefficient K ₄ is set based on the deterioration degree difference ΔDL of the secondary battery 2, and the charge output is obtained by multiplying the correction coefficient K ₄ by the basic electrical output Q _FC. Calculated as Q. Correction factor K ₄ is a coefficient that acts to increase the electrical output of the small deterioration cell as compared to a large deterioration battery. That is, as the deterioration degree DL of the charging battery charged by the fuel cell 3 is higher, the electric output of the fuel cell 3 is reduced.
Therefore, as the deterioration degree DL of the secondary battery 2 that has progressed relatively deteriorates, the progress of the deterioration can be suppressed, and the deterioration states of the plurality of secondary batteries 2 can be equalized. In addition, the relative deterioration state of the secondary battery 2 is directly reflected in the electric output of the fuel cell 3 as compared with the case where the electric output of the fuel cell 3 is controlled based on the charging rate decrease rate X. And the effect of equalizing the deterioration state can be enhanced.

[7-2. Setting of charge / discharge area]
(1) In the power control apparatus 1 described above, the relative deterioration degree of the plurality of secondary batteries 2 is determined, and the allowable fluctuation range of the charging rate SOC of each secondary battery 2 is determined according to the deterioration degree. Is set. For example, the allowable fluctuation range of the charge rate SOC of the large deterioration battery is set to be narrower than the allowable fluctuation range of the charge rate SOC of the small deterioration battery, and the allowable fluctuation of the charge rate SOC as the deterioration progresses. The width is narrowed. As a result, as shown in FIGS. 12A and 12B, the highly deteriorated battery completes charging earlier than the small deteriorated battery, or discharge is completed earlier, and the large deteriorated battery than the small deteriorated battery. Substantial use time (cumulative use time) is reduced.

  Thus, by setting the width of the fluctuation range of the charging rate SOC according to the relative deterioration degree, the usage time and usage frequency of the battery can be changed. Therefore, if a setting that reduces the usage time and usage frequency of the battery for which the progress of deterioration is to be suppressed is used, the progress of deterioration can be suppressed and the deterioration state can be equalized. In addition, since the allowable fluctuation range of the charging rate SOC is narrowed, the highly deteriorated battery is operated in a stable state without the charging rate SOC changing greatly. Even in this respect, the deterioration can be effectively suppressed, and the deterioration state can be equalized.

(2) Further, in the power control device 1, upper limit charge rate SOC _MAX large deterioration battery is set to a value smaller than the upper limit charge rate SOC _MAX small deterioration battery. Thereby, compared with a small deterioration battery, a large deterioration battery becomes difficult to be in an overcharge state, and the electrical load given to the secondary battery 2 decreases. Therefore, the progress of the deterioration of the large deterioration battery can be suppressed as compared with the small deterioration battery, and the deterioration state of each secondary battery 2 can be equalized.
In addition, by equalizing the deterioration state of each secondary battery 2, it is possible to increase the power that can be used in the entire secondary battery 2, and to suppress a decrease in usable battery capacity. it can. Thereby, the service life of the secondary battery 2 can be extended and cost performance can be improved.

(3) In the power control device 1 described above, not only the upper limit charging rate SOC _MAX but also the lower limit charging rate SOC _MIN is set according to the degree of deterioration. That is, the lower limit charging rate SOC _MIN large deterioration battery is set to a value larger than the lower limit charging rate SOC _MIN small deterioration battery. Thereby, compared with a small deterioration battery, a large deterioration battery becomes difficult to be in the state of deep discharge, and the electrical load given to the secondary battery 2 decreases. Therefore, the progress of the deterioration of the large deterioration battery can be suppressed as compared with the small deterioration battery, and the deterioration state of each secondary battery 2 can be equalized.

(4) Further, each of the values of upper limit charge rate SOC _MAX and the lower limit charging rate SOC _MIN above is set across the 50%. Thereby, the state of at least 50% charge rate is included in the charge / discharge area of each secondary battery 2. Further, the allowable fluctuation range of the secondary battery 2 is narrowed so as to gradually approach 50% as the deterioration progresses. That is, as the deterioration progresses, charging / discharging is repeated in a stable region where the deterioration hardly progresses.
Therefore, the progress of deterioration of the secondary battery 2 can be efficiently suppressed. Moreover, since the progress speed | rate becomes slow, so that the deterioration of the secondary battery 2 progresses, the deterioration state of the some secondary battery 2 can be equalized.

(5) Moreover, as shown in FIG.12 (b), compared with a small deterioration battery, the time in which a large deterioration battery is left in a full charge state tends to become long. On the other hand, when the upper limit charging rate SOC _MAX of the highly deteriorated battery is set to 50%, the charging rate SOC of the fully charged state in which charging is completed is maintained at 50%. Therefore, it is possible to maintain the state of the charge rate SOC in which the deterioration hardly proceeds for a long time, to suppress the progress of the deterioration, and to equalize the deterioration state of the individual secondary batteries 2.

(6) Further, the upper limit charging rate SOC _MAX set at the time of external charging is set larger than the upper limit charging rate SOC _MAX set at the time of charging by the fuel cell 3 during normal driving, so that a certain degree of secondary The charging capacity of the battery 2 can be ensured. Meanwhile, the deterioration higher charging rate SOC is likely to proceed, the upper limit charge SOC _MAX large deterioration battery is set to be smaller than the upper limit charge SOC _MAX of at least a small deterioration battery. Thereby, progress of deterioration can be suppressed, ensuring charging capacity.

Similarly to the charging by the fuel cell 3, the upper limit charging rate SOC _MAX at the time of external charging is set to a size according to the deterioration state of each secondary battery 2. That is, the upper limit charging rate SOC _MAX of the secondary battery 2 having a high degree of deterioration DL is set slightly lower, and the upper limit charging rate SOC _MAX of the secondary battery 2 having a low degree of deterioration DL is set slightly higher. Therefore, the cruising distance can be secured with a sufficient charging capacity, and the deterioration state of each secondary battery 2 can be equalized.

[7-3. Switching charge / discharge target]
(1) In the power control device 1 described above, while one of the two secondary batteries 2 functions as a discharge battery, the other is a charge battery. The determination of the charging / discharging role switching condition is changed according to the deterioration degree DL of each secondary battery 2. In this way, by changing the conditions for changing the discharge target based on the relative degree of deterioration of the secondary battery 2, it is possible to select a discharge mode in which deterioration does not easily progress while suppressing the occurrence of electric shortage. The progress of deterioration of the secondary battery 2 can be suppressed. Thereby, the deterioration state of each secondary battery 2 can be equalized.

(2) The switching determination unit 18 of the power control apparatus 1 is provided with a first changing unit 18a that determines a first switching condition related to the charge rate SOC of the discharge battery. As a result, regardless of the degree of deterioration DL of the charging target, it is possible to effectively use the power of the discharging target while securing the charging capacity.
On the other hand, the switching determination unit 18 is provided with a second changing unit 18b that determines a second switching condition related to the charging rate SOC of the rechargeable battery. Thereby, it is possible to switch between the charging target and the discharging target in accordance with the deterioration degree DL, and it is possible to equalize the cumulative usage time. Accordingly, it is possible to suppress the progress of deterioration biased toward only one secondary battery 2.

(3) For example, when the large deterioration battery is a discharge battery, it is considered that the discharge output D bottoms out earlier than when the small deterioration battery is a discharge battery. Therefore, in the above-described embodiment, in addition to the first switching condition described above, when the charging rate SOC of the charging battery becomes _{equal to} or higher than the upper limit charging rate SOC _{MAX_CHA} , the charging battery and the discharging battery are switched. Yes. In other words, even when the charge rate SOC of the _highly deteriorated battery has not decreased below the lower limit charge rate SOC _{MIN_DIS, when the} charge of the _slightly deteriorated battery is completed, the small deteriorated battery is discharged. By such control, the fluctuation range of the substantial charge rate SOC of the highly deteriorated battery can be further narrowed, and the cumulative use time of the highly deteriorated battery can be relatively shortened to suppress the progress of deterioration. can do.

(4) When the small deterioration battery is a discharge battery, it is considered that the deterioration degree of the rechargeable battery is relatively large and the charge capacity is slightly reduced. Therefore, in the above-described embodiment, the charging battery and the discharging battery are not changed until the charging rate SOC of the discharging battery becomes equal to or lower than the lower limit charging rate SOC _{MIN_DIS} . By such control, it is possible to secure a charge amount to the secondary battery 2 that has deteriorated.

Further, even when the state of charge of the _highly deteriorated battery becomes fully charged, the discharge state of the _slightly deteriorated battery is maintained as long as the charge rate SOC of the _slightly deteriorated battery does not _fall below the lower limit charge rate SOC _{MIN_DIS} . That is, in this case, the highly deteriorated battery is in an unused state where no electrical load acts. Therefore, the cumulative use time of the highly deteriorated battery can be relatively shortened, and the progress of deterioration can be suppressed.

  (5) Also, when the deterioration degree of the secondary battery 2 is uniform, the selection order of the discharge batteries is a predetermined order, so that the cumulative usage time of each secondary battery 2 can be made substantially uniform, The deterioration state can be equalized. On the other hand, when a large variation occurs in the degree of deterioration of the secondary battery 2, the highly deteriorated battery is the first discharge target after completion of external charging. As described above, by preferentially discharging the highly deteriorated battery, it is possible to shorten the time during which the state of charge SOC of the highly deteriorated battery remains high.

  Further, by lowering the charge rate SOC of the highly deteriorated battery as early as possible, it is possible to approach a state of stable charge rate SOC (a charge rate of 50%) where deterioration is less likely to proceed. Therefore, the progress of deterioration can be suppressed, and the deterioration state of the secondary battery 2 can be equalized.

  (6) For example, when there are three or more secondary batteries 2 and there are a plurality of batteries that are classified as highly deteriorated batteries, the selection order of the discharge batteries is changed in descending order of the deterioration degree DL. By such scheduling, it is possible to preferentially discharge the large deterioration battery over the small deterioration battery, and to suppress the progress of deterioration. Therefore, the deterioration state of the secondary battery 2 can be equalized.

[7-4. Compensation of discharge output]
(1) In the power control device 1 described above, the discharge output D from the large deterioration battery which is a discharge battery is limited according to the deterioration degree DL. For example, a value _obtained by multiplying the standard maximum electrical output Q _MAXBASE by the correction coefficient K ₅ set based on the deterioration degree difference ΔDL is set as the maximum electrical output Q _{MAX of the highly} deteriorated battery. Thereby, since the taking out of the high output from a large deterioration battery is suppressed, progress of deterioration can be suppressed and the deterioration state of the secondary battery 2 can be equalized.

(2) When the required electrical output Q _M of the motor 4 exceeds the maximum electrical output Q _MAX of the discharge battery, the insufficient output is supplemented from the fuel cell 3 or the small deterioration battery. Therefore, it is possible to supply electric power without excess or deficiency to the required electric output Q _M of the motor 4 while suppressing the high output from the highly deteriorated battery, and to ensure the acceleration performance and running performance of the vehicle 20. be able to.

(3) Further, in the power control device 1 described above, if the fuel cell 3 is in an activated state (that is, when the small deterioration battery is being charged or in a power generation idle state), the actual power generation output Q _TGT of the fuel cell 3 Is calculated based on the electric output assist amount Q _ASST . The electrical output assist amount Q _ASST is obtained by multiplying the value obtained by subtracting the maximum electrical output Q _MAX from the required electrical output Q _M by the correction coefficient L. _Further , an added value (Q + Q _ASST ) of the charging output Q used for charging the small deterioration battery and the electric output assist amount Q _ASST is set as the actual power generation output Q _TGT of the fuel cell 3. As a result, an electrical output commensurate with the insufficient electrical output can be quickly supplied from the fuel cell 3 to the motor 4. Moreover, according to the electric output capability of the fuel cell 3, the electric output can be compensated while charging is continued.

(4) When the added value (Q + Q _ASST ) of the charging output Q and the electric output assist amount Q _ASST is _{equal to} or greater than the maximum electric output Q _{FC_MAX} of the fuel cell 3, the maximum electric output Q _{FC_MAX} is the fuel cell 3 The actual power output of Q _TGT . At this time, the electric output transmitted to the motor 4 side becomes the electric output assist amount Q _ASST , and the charging input C supplied to the small deterioration battery decreases. Therefore, even if there is not enough electrical output of the fuel cell 3, slightly reduce the charge amount supplied to the rechargeable battery, it is possible to secure the required electrical output Q _M of the motor 4.

(5) If the fuel cell 3 is not activated (that is, a stopped state after the charging of the small deterioration battery has already been completed), the motor 4 is driven not only from the large deterioration battery but also from the small deterioration battery. Power is supplied. At this time, both of the two secondary batteries 2 simultaneously function as discharge batteries. With such an electric output assist, the required electric output Q _M of the motor 4 can be met without unnecessarily starting the fuel cell 3, and the fuel consumption of the fuel cell 3 can be reduced while ensuring the running performance of the vehicle 20. Can be suppressed.

(6) In addition, the discharge load of the discharge battery is obtained by performing the electrical output assist by causing the rechargeable battery having a low relative deterioration degree DL to function as a temporary discharge battery with respect to the discharge battery having a high relative deterioration degree DL. Can be reduced. Thereby, progress of deterioration can be suppressed efficiently and the deterioration state of the secondary battery 2 can be equalized efficiently. Furthermore, if the discharge output E of the provisional discharge battery is increased to cover the added value (Q _ASST + Q _MAX ) of the electrical output assist amount Q _ASST and the maximum electrical output Q _MAX of the discharge battery, Usage time and usage frequency can be reduced, and the effect of suppressing deterioration can be further improved.

[7-5. Pause charging]
(1) In the power control device 1 described above, when a predetermined charging suspension condition is satisfied, the fuel cell 3 is temporarily controlled to the power generation idle state, and charging of the charging cell by the fuel cell 3 is temporarily interrupted. . Further, as the charge suspension condition, the charge rate SOC of the discharge battery and the battery temperature T of the charge battery are determined. In this way, by determining whether or not charging is possible based on the charging rate SOC of the charging target and the battery temperature T of the charging target, the remaining power of the charging input C and the influence of the charging environment temperature on the degradation degree DL Charging can be carried out or interrupted depending on the size. Thereby, deterioration of the secondary battery 2 can be suppressed without generating electric shortage, and the deterioration state of the secondary battery 2 can be equalized.

(2) Moreover, in said electric power control apparatus 1, when the charge rate SOC of a discharge battery is less than a dormant determination charge rate SOC _PAUSE , the charge to a charge battery is not interrupted. Thereby, when the remaining power of the discharge battery decreases, the discharge battery and the rechargeable battery can be switched immediately, and a shortage of electricity can be reliably prevented. In addition, since there is a surplus in the power of the discharge battery and the battery temperature T of the rechargeable battery exceeds the pause temperature T _PAUSE , charging is suspended, so it is possible to avoid applying an electrical load to the rechargeable battery at a high temperature. The progress of deterioration can be effectively suppressed.

(3) Also, by setting the pause temperature T _PAUSE based on the relative degradation degree DL (degradation degree difference ΔDL) of the rechargeable battery, it is possible to suspend the charge according to the temperature environment of the rechargeable battery. Can be efficiently suppressed. On the other hand, by setting the predetermined charging rate according to the relative degradation degree DL of the discharge battery, it is possible to stop charging according to the remaining capacity of the discharge battery SOC and efficiently suppress the progress of deterioration can do.

(4) For example, since the pause temperature T _PAUSE when charging a highly deteriorated battery is set lower than the pause temperature T _PAUSE when charging a _slightly deteriorated battery, a large deterioration with a large degree of deterioration in a relatively low temperature environment The battery can be charged, and the progress of deterioration can be efficiently suppressed.
Further, the higher the relative deterioration degree DL of the large deterioration battery with respect to the small deterioration battery, the lower the pause temperature T _PAUSE is set. Therefore, it is possible to easily stop the charging of the highly deteriorated battery, the progress of deterioration can be effectively suppressed, and the deterioration states of the plurality of secondary batteries 2 can be equalized.

(5) Further, for example, the pause determination charging rate SOC _PAUSE at the time of discharging the large deterioration battery is set higher than the pause determination charging rate SOC _PAUSE at the time of discharging the small deterioration battery. A highly deteriorated battery can be charged, and a shortage of electricity can be more reliably prevented. Furthermore, a battery having a high degree of deterioration may have a reduced discharge characteristic even if the charging rate SOC is high, and there is a possibility that power will be exhausted after a short period of use. On the other hand, by setting the pause determination charging rate SOC _PAUSE according to the degree of deterioration of the discharge target, charging can be paused according to the remaining capacity of the charging input C, and the progress of deterioration can be efficiently suppressed. .

In the power control apparatus 1 described above, the pause determination charging rate SOC _PAUSE is set higher as the relative deterioration degree DL of the large deterioration battery with respect to the small deterioration battery is higher. Therefore, regarding the small deterioration battery, unlike the large deterioration battery, it is possible to make it difficult to stop the charging, and it is possible to more reliably prevent shortage.

  (6) In the power control device 1 described above, the fuel cell 3 is controlled to the power generation idle state when the charging suspension condition is satisfied. In this power generation idle state, since the fuel supply to the fuel cell 3 is continued, the charging can be restarted quickly when the charging suspension condition is not satisfied. Therefore, it is possible to effectively suppress the progress of deterioration while avoiding the occurrence of electric shortage.

[8. Modified example]
Regardless of the embodiment described above, various modifications can be made without departing from the spirit of the invention. Each structure of this embodiment can be selected as needed, or may be combined appropriately.

  For example, the power control apparatus 1 described above can be applied to a hybrid vehicle that includes an engine and a motor 4 as a drive source of the vehicle 20. As long as the vehicle 20 includes at least the secondary battery 2 as a power source of the motor 4 and further includes the fuel cell 3 that charges the secondary battery 2, the above-described control can be performed. In the above-described embodiment, the case where the number of the secondary batteries 2 is two has been described in detail, but the number of the secondary batteries 2 may be three or more. In this case, the selection order of the discharge battery and the rechargeable battery in the target setting unit 12 may be determined by applying a known scheduling method.

DESCRIPTION OF SYMBOLS 1 Power control apparatus 2 Secondary battery 2a 1st battery 2b 2nd battery 3 Fuel cell 4 Motor (electric equipment)
DESCRIPTION OF SYMBOLS 5 Fuel tank 6 Converter 7 Inverter 8 Car-mounted charger 9 Control circuit 10 Electronic controller 11 Degradation degree determination part (determination means)
12 target setting part 13 external charge control part (external charge control means)
14 Charge / Discharge Control Unit (Control Unit)
15 Basic electrical output calculation unit (electrical output control means)
16 Charge / discharge area calculation part (charge / discharge area control means)
17 Charge / Discharge Output Calculation Unit (Charge / Discharge Output Control Unit)
18 Switching judgment part (change judgment means)
18a 1st change part (1st change means)
18b 2nd change part (2nd change means)
19 Charging suspension determination unit (suspending control means)
20 vehicles

Claims (6)

A plurality of secondary batteries that are connected to electrical equipment and whose charge / discharge states are controlled independently of each other;
A fuel cell connected to the plurality of secondary batteries and charging each of the secondary batteries;
A control means for setting a discharge target and a charge target from the plurality of secondary batteries, and controlling a discharge state from the discharge target to the electrical device and a charge state from the fuel cell to the charge target;
Based on the rate of decrease of the charging rate of the secondary battery set as the discharge target , the electricity of the fuel cell supplied to the secondary battery set as the charge target when the rate decrease is detected An electric power control device comprising an electric output control means for increasing / decreasing the output. The power control apparatus according to claim 1, wherein the increase / decrease control of the electric output of the fuel cell by the electric output control means is further controlled based on a charging rate of the charging target. The electric output control means increases the electric output of the fuel cell as the charging rate of the charging target is lower and as the rate of decrease of the charging rate of the discharging target is higher. Power control device. When the electric output control means sets the electric output of the fuel cell, the charging rate of the charging target is more strongly reflected in the magnitude of the electric output of the fuel cell than the rate of decrease of the charging rate of the discharging target. The power control apparatus according to claim 3, wherein the power control apparatus is characterized. Determination means for determining a relative deterioration degree for each of the plurality of secondary batteries,
The electrical output control means, when the charge target is determined by the determination means to be relatively small in degree of deterioration, is based on the relative deterioration degree of the charge target with respect to the discharge target. The power control apparatus according to any one of claims 1 to 4, wherein the electric output is corrected.   A plurality of secondary batteries that are connected to electrical equipment and whose charge / discharge states are controlled independently of each other;
  A fuel cell connected to the plurality of secondary batteries and charging each of the secondary batteries;
  A control means for setting a discharge target and a charge target from the plurality of secondary batteries, and controlling a discharge state from the discharge target to the electrical device and a charge state from the fuel cell to the charge target;
  An electric output control means for increasing / decreasing an electric output of the fuel cell supplied to the charging target based on a rate of decrease of the charging rate of the discharging target;
  Determination means for determining a relative deterioration degree for each of the plurality of secondary batteries,
  The electrical output control means, when the charge target is determined by the determination means to be relatively small in degree of deterioration, is based on the relative deterioration degree of the charge target with respect to the discharge target. Compensate for electrical output
An electric power control apparatus.

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