JP5659941B2 - Charge control device - Google Patents

Description

  The present invention relates to a technology of a secondary battery charge control device.

  An electric vehicle such as a hybrid vehicle equipped with an electric motor (motor) drives the electric motor with electric power stored in a secondary battery. In such an electric vehicle, for example, an electric motor is generated using an engine as a power source to charge a secondary battery, or when the vehicle is braked, the electric motor functions as a generator to convert kinetic energy of the vehicle into electric energy. Recharge the secondary battery.

  The secondary battery has a problem in that gas generation occurs due to a side reaction of charging as the voltage increases during charging, and the internal pressure of the secondary battery increases. For example, in a nickel metal hydride secondary battery, when a predetermined voltage or higher is reached, oxygen gas is mainly generated and the internal pressure rises.

  For example, Patent Document 1 discloses that a physical quantity of a secondary battery that affects the internal pressure of the secondary battery and an index (characteristic change index) representing a change in the internal pressure characteristics of the secondary battery calculated based on the physical quantity. There has been proposed a charge control device that estimates the internal pressure of a secondary battery and performs charge control of the secondary battery based on the estimated internal pressure of the secondary battery. According to the charge control device of Patent Document 1, an increase in the internal pressure of the secondary battery is suppressed, and the secondary battery can be protected.

JP 2007-53058 A

  By the way, it is desirable for the charge control device for the secondary battery to improve the fuel efficiency of the vehicle by controlling the target charge amount set for the secondary battery. Although it is possible to improve the fuel efficiency of the vehicle by increasing the target charge amount of the secondary battery as much as possible, the internal pressure of the secondary battery increases even if the target charge amount is simply increased. As a result, the input charge amount is limited.

  Then, this invention is providing the charge control apparatus of the secondary battery which can improve the fuel consumption performance of a vehicle, suppressing the internal pressure rise of a secondary battery.

The charge control device according to the present invention is based on target charge amount setting means for setting a target charge amount of the secondary battery based on a charge state of the secondary battery, and a voltage and current between terminals of the secondary battery. An electromotive force calculating means for calculating an electromotive voltage of the secondary battery, and a voltage determination for determining whether the electromotive voltage of the secondary battery is equal to or higher than a gas generation potential at which gas generation occurs in the secondary battery. And when the electromotive voltage of the secondary battery is greater than or equal to the gas generation potential, the target charge amount is limited, and when the electromotive voltage of the secondary battery is less than the gas generation potential, Control means for controlling the target charge amount so as to maintain or increase the target charge amount, and internal pressure estimation means for estimating the internal pressure of the secondary battery based on the voltage, current value and temperature between the terminals of the secondary battery; Whether the internal pressure of the secondary battery is equal to or higher than a predetermined value. Comprising a pressure determination unit constant for the said control unit, when the electromotive voltage of the secondary battery is not less the gas evolution potential and not more than the internal pressure of the secondary battery is a predetermined value or more, the target charge The amount of charge is limited, and when the electromotive voltage of the secondary battery is less than the gas generation potential, or when the internal pressure of the secondary battery is less than a predetermined value, the target charge amount is maintained or increased. And the secondary battery is charged based on the controlled target charge amount.

  In the charge control device, the control means limits the target charge amount, so that the electromotive voltage of the secondary battery is less than the gas generation potential or the internal pressure of the secondary battery is less than a predetermined value. In such a case, it is preferable to release the restriction on the target charge amount.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel consumption performance of a vehicle can be improved, suppressing the internal pressure raise of a secondary battery.

It is a mimetic diagram showing the composition of the hybrid car which shows one embodiment of the present invention. It is a figure which shows the relationship between the electromotive voltage of a battery, and gas generation potential. It is a flowchart for demonstrating the control method of the target charge amount which concerns on this embodiment. It is a map showing the relationship between internal resistance and battery temperature. It is a map showing the relationship between battery temperature and gas generation potential. It is a map showing the relationship between the remaining capacity of a battery and a reference | standard target charge amount. (A) is a map showing the relationship between the target charge amount increase rate β and the battery temperature, and (B) is a map showing the relationship between the target charge amount increase rate β and the estimated internal pressure of the battery. . It is a flowchart for demonstrating another example of the control method of the target charge amount which concerns on this embodiment.

  Embodiments of the present invention will be described below.

  FIG. 1 is a schematic diagram showing a configuration of a hybrid vehicle showing an embodiment of the present invention. A hybrid vehicle 20 shown in FIG. 1 is connected to an engine 22, a three-shaft power distribution integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and the power distribution integration mechanism 30. The motor MG1 capable of generating electricity, the reduction gear 35 attached to the ring gear shaft 32a as a drive shaft connected to the power distribution and integration mechanism 30, the motor MG2 connected to the reduction gear 35, and the entire power output device And a hybrid electronic control unit 70 for controlling the control.

  The engine 22 is an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil, and an engine electronic control unit (hereinafter referred to as an engine ECU) that receives signals from various sensors that detect the operating state of the engine 22. ) 24 is subjected to operation control such as fuel injection control, ignition control, intake air amount adjustment control and the like. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70.

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. In the power distribution and integration mechanism 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 via the ring gear shaft 32a. When functioning as a generator, power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine input from the carrier 34 The power from 22 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the drive wheels 63a and 63b of the vehicle via the gear mechanism 60 and the differential gear 62.

  The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG1 and MG2 It can be consumed by a motor. Therefore, battery 50 is charged / discharged by electric power generated from one of motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 receives signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 for detecting the rotational positions of the rotors of the motors MG1 and MG2, and a current sensor 53 (not shown). The detected phase current applied to the motors MG1 and MG2 is input, and the motor ECU 40 outputs a switching control signal to the inverters 41 and 42. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 is attached to a signal necessary for managing the battery 50, for example, a voltage between terminals from the voltage sensor 49 installed between the terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the current sensor 53, the battery temperature from the temperature sensor 51 attached to the battery 50, and the like are input, and data regarding the state of the battery 50 is communicated by communication as necessary. Output to. In addition, the battery ECU 52 calculates an integrated value of the charging current detected by the current sensor 53 and a remaining capacity (SOC) based on the integrated value in order to manage the battery 50. The battery 50 is a chargeable / dischargeable secondary battery, such as a lithium ion secondary battery or a nickel hydride secondary battery.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. The accelerator pedal opening Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. ing.

  In the operation of the hybrid vehicle 20 configured as described above, the engine 22 outputs power that matches the sum of the required power corresponding to the required torque to be output to the ring gear shaft 32a and the target charge amount required for charging the battery 50. As described above, there is a mode for controlling the operation of the engine 22. The required power is calculated based on the accelerator opening Acc corresponding to the depression amount of the accelerator pedal 83 by the driver and the vehicle speed V, and is output to the ring gear shaft 32a so that the engine 22, the motor MG1, and the motor MG2 Is controlled.

  Further, the target charge amount necessary for charging the battery 50 is generally set based on the remaining capacity of the battery 50. Then, if the reference target charge amount is simply increased on the basis of the target charge amount set based on the remaining capacity of the battery 50, the fuel efficiency of the hybrid vehicle 20 can be improved. Due to this side reaction, gas is generated in the battery 50 and the internal pressure of the battery 50 rises more than necessary. As a result, it is necessary to limit the amount of charge input to the battery 50.

  FIG. 2 is a diagram showing the relationship between the electromotive voltage of the battery and the gas generation potential. The gas generation potential is a potential at which gas generation occurs due to a side reaction during charging. As shown in FIG. 2, when the voltage increases due to charging and the electromotive voltage of the battery 50 becomes equal to or higher than the gas generation potential, gas generation occurs. For example, in a nickel metal hydride secondary battery, oxygen gas is generated when the electromotive voltage of the battery exceeds the gas generation potential.

  Therefore, in this embodiment, the target charge amount is controlled based on the gas generation potential at which gas generation occurs in the battery 50, the increase in the internal pressure of the battery 50 is suppressed, and the fuel efficiency of the vehicle is improved. Specifically, as described later, when the electromotive voltage of the battery 50 is equal to or higher than the gas generation potential, the target charge amount is limited, and when the electromotive voltage of the battery 50 is less than the gas generation potential, the target charge amount is maintained or increased. Implement such control.

  The target charge amount control method executed mainly by the hybrid electronic control unit 70 will be described below.

  FIG. 3 is a flowchart for explaining the target charge amount control method according to the present embodiment. As shown in FIG. 3, first, in step S10, the voltage sensor 49, the current sensor 53, and the temperature sensor 51 detect the voltage between terminals of the battery 50, the current value, and the battery temperature. In step S <b> 12, the battery ECU 52 calculates the internal resistance of the battery 50 based on the inter-terminal voltage and current value of the battery 50. The calculation of the internal resistance of the battery 50 is not particularly limited. For example, a plurality of current values and voltage values are plotted on the voltage / current coordinates, and a primary approximation expression is obtained along each plotted point. The slope of the straight line represented by this approximate expression is calculated as the internal resistance. Further, since the internal resistance changes depending on the battery temperature, it is stored in the battery ECU 52 as a map representing the relationship between the internal resistance and the battery temperature, and when the battery temperature is given, the corresponding internal resistance is determined from the map. May be calculated. An example of this map is shown in FIG. When a plurality of temperature sensors 51 are set, the highest detected temperature among the temperature sensors 51 is applied to a map or the like representing the relationship between the internal resistance and the battery temperature shown in FIG. Is preferably set.

Next, in step S <b> 14, the battery ECU 52 calculates the electromotive voltage (OCV) of the battery 50 based on the inter-terminal voltage, current value, and internal resistance of the battery 50. Here, the electromotive voltage of the battery 50 is a voltage between the positive and negative electrodes of the battery 50, a so-called voltage between electrodes, and a current (current sensor) that flows to the battery 50 from the voltage between the terminals of the battery 50 detected by the voltage sensor 49. The current value detected by 53) and the IR of the internal resistance of the battery 50 are obtained by the following equation (1). That is, the following expression (1) is stored in the battery ECU 52, and the electromotive voltage of the battery 50 is calculated by applying the given inter-terminal voltage, current value, and internal resistance of the battery 50 to the following expression (1). The
V ₀ = VB + (IB × R) (1)
V ₀ : Electromotive voltage of battery 50 VB: Voltage between terminals of battery 50 IB: Current value of battery 50 (the charging side is negative)
R: Internal resistance of battery 50

  When the battery 50 is composed of a plurality of blocks each having a predetermined number of cells, and the voltage between terminals is measured for each block, the highest value among the voltages for each block is determined between the terminals of the battery 50. It is desirable to calculate the electromotive voltage of the battery 50 using the voltage. Further, the electromotive voltage for each block may be obtained using the voltage between terminals for each block, and the highest value among them may be used as the electromotive voltage of the battery 50. Further, when calculating the electromotive voltage of the battery 50, for example, it is desirable to set an annealing (filter) of about several seconds in each sensor or the battery ECU 52 to remove the influence of noise or the like.

  Then, the hybrid electronic control unit 70 compares the calculated electromotive voltage of the battery 50 with the gas generation potential stored in advance. If the electromotive voltage of the battery 50 is equal to or higher than the gas generation potential, the process proceeds to step S16. As will be described later, the target charge amount of the battery 50 is limited by a predetermined amount, and when the electromotive voltage of the battery 50 is less than the gas generation potential, the process proceeds to step S18, and the target charge amount of the battery 50 is maintained or set as described later. Increase quantitatively. The comparison between the calculated electromotive voltage of the battery 50 and the gas generation potential is continuously performed. After the target charge amount of the battery 50 is limited by a predetermined amount in step S16, the electromotive voltage of the battery 50 becomes less than the gas generation potential. Sometimes, the restriction on the target charge amount of the battery 50 is released (for example, a predetermined amount is increased). In step S20, the battery 50 is charged based on the controlled target charge amount.

  The gas generation potential described above may be a predetermined default value. However, since the gas generation potential depends on the temperature of the battery 50, for example, a map or the like obtained in advance for the relationship between the battery temperature and the gas generation potential is stored in the ROM 74. It is desirable to set by deriving the gas generation potential from the map when the temperature of the battery 50 is given. An example of this map is shown in FIG. When a plurality of temperature sensors 51 are set, the highest detected temperature among the temperature sensors 51 is applied to a map or the like representing the relationship between the battery temperature and the gas generation potential shown in FIG. It is preferable to set the generated potential.

  An example of a method for limiting or increasing the target charge amount of the battery 50 in step S16 or step S18 will be described. For example, when limiting the target charge amount, the hybrid electronic control unit 70 calculates the target charge amount serving as a control reference, and multiplies the target charge amount serving as the control reference by a predetermined limit rate α, A limited target charge is required. For example, when the target charge amount is increased, the hybrid electronic control unit 70 obtains the increased target charge amount by multiplying the target charge amount serving as a control reference by a predetermined increase rate β.

Here, the target charge amount serving as a control reference is set based on the remaining capacity of the battery 50. For example, first, the remaining capacity (SOC) of the battery 50 is calculated by the battery ECU 52 based on the integrated value of the charging current. Then, a map or the like obtained in advance for the relationship between the remaining capacity of the battery 50 and the target charge amount as a control reference is stored in the ROM 74, and when the remaining capacity of the battery 50 is given, the corresponding target charge amount is obtained from the map. Set by deriving. An example of this map is shown in FIG. In FIG. 6, as the remaining capacity of the battery 50 becomes smaller than a certain reference value (C ₀ ), the value of the target charge amount serving as a control reference is increased, and when the remaining capacity of the battery 50 is less than a predetermined value (C ₁ ), the control reference _Are related so that the target charge amount value becomes a certain maximum value (P _chg MAX). Although not directly related to the control of the present embodiment, the target discharge amount is increased as the remaining capacity of the battery 50 increases with a certain value (C ₀ ) as a reference, and the remaining capacity of the battery 50 exceeds a predetermined value. In some cases, the target discharge amount is related to a certain maximum value.

  Further, a map may be prepared in which the relationship between the remaining capacity of the battery 50 and the target charge amount serving as a control reference is defined according to the temperature of the battery 50. For example, when the temperature of the battery 50 is within a predetermined range, the map is set to be a value larger than the target charge amount value serving as a control reference shown in FIG. When it is outside, it is set to the value of the target charge amount that is the control reference shown in FIG. This predetermined range is set as appropriate.

  The limit rate α and the increase rate β described above preferably vary depending on the battery temperature and the estimated internal pressure value of the battery 50 described later in that the target charge amount can be controlled more appropriately. For example, a map showing the relationship between the target charge amount increase rate β and the battery temperature (see FIG. 7A), and a map showing the relationship between the target charge amount increase rate β and the estimated internal pressure of the battery 50 (FIG. 7). (See (B)) is stored in the ROM 74, and when the temperature of the battery 50 and the estimated internal pressure of the battery 50 are given, the corresponding increase rate β is derived from the map. The target charge amount is increased by multiplying the target charge amount as the control reference by the increase rate β derived in this way. It is preferable to derive the limiting rate α in the same manner. In the control of the target charge amount, when the target charge amount is increased, the maximum value of the target charge amount determined based on the remaining capacity of the battery 50 may be set as the upper limit.

  FIG. 8 is a flowchart for explaining another example of the target charge amount control method according to the present embodiment. As shown in FIG. 8, in step S <b> 30, the voltage sensor 49, the current sensor 53, and the temperature sensor 51 detect the inter-terminal voltage, current value, and battery temperature of the battery 50. In step S <b> 32, the internal resistance of the battery 50 is calculated by the battery ECU 52 based on the inter-terminal voltage and current value of the battery 50. The calculation method of the internal resistance is as described above. Next, in step S34, the battery ECU 52 applies the inter-terminal voltage, current value, and internal resistance value of the battery 50 to the above equation (1) to calculate the electromotive voltage (OCV) of the battery 50. In step S36, the internal pressure of the battery 50 is estimated by the battery ECU 52 from the voltage between the terminals of the battery 50, the current value, and the battery temperature. A method for estimating the internal pressure of the battery 50 will be described later.

Then, the hybrid electronic control unit 70 compares the calculated electromotive voltage of the battery 50 with the gas generation potential, and also compares the estimated internal pressure value of the battery 50 with a predetermined value to determine the electromotive voltage of the battery 50. Is equal to or greater than the gas generation potential and the estimated internal pressure of the battery 50 is equal to or greater than the predetermined value, the process proceeds to step S36, the target charge amount of the battery 50 is limited by a predetermined amount, and the electromotive voltage of the battery 50 is less than the gas generation potential. If the estimated internal pressure value of the battery 50 is less than the predetermined value, the process proceeds to step S38, and the target charge amount of the battery 50 is maintained or increased by a predetermined amount. The comparison between the calculated electromotive voltage of the battery 50 and the gas generation potential and the comparison between the estimated internal pressure value of the battery 50 and the predetermined value are continuously executed. After the target charge amount of the battery 50 is limited by a predetermined amount in step S36, When the electromotive voltage of the battery 50 is less than the gas generation potential or the estimated internal pressure of the battery 50 is less than a predetermined value, the restriction on the target charge amount of the battery 50 is released (for example, the predetermined amount is increased). In step S40, the battery 50 is charged based on the controlled target charge amount. The method of limiting or increasing the target charge amount of the battery 50 is as described above.

  Although an example of the internal pressure estimation method of the battery 50 will be described below, the present invention is not limited to this, and all conventionally known internal pressure estimation methods are applied.

  The internal pressure of the battery 50 is calculated by the sum of the equilibrium hydrogen pressure and the oxygen pressure in the battery 50. The equilibrium hydrogen pressure in the battery 50 is calculated based on the temperature of the battery 50. The oxygen pressure in the battery 50 is obtained from the difference between the oxygen gas generation amount and the oxygen gas decrease amount in the battery 50. The oxygen gas generation amount is calculated based on the current value and the charging efficiency of the battery 50, and the oxygen gas decrease amount is calculated based on the temperature of the battery 50. Hereinafter, these will be described in detail.

  Since the equilibrium hydrogen pressure in the battery 50 depends on the temperature of the battery 50, for example, a map representing the relationship between the temperature of the battery 50 and the equilibrium hydrogen pressure in the battery 50 is stored in the ROM 74 in advance, and the temperature sensor is stored in the map. By applying the temperature of the battery 50 detected by 51, the equilibrium hydrogen pressure in the battery 50 is calculated.

Further, as described above, the oxygen pressure in the battery 50 is calculated by the difference between the oxygen gas generation amount and the oxygen gas decrease amount. This is because oxygen gas is generated by a side reaction during charging, but oxygen gas is absorbed by an electrode opposite to the gas generating electrode. Specifically, it is calculated by the following equation (2). The following expression (2) is an expression for calculating the oxygen pressure based on the amount of oxygen gas in the battery 50 per unit time.
P ₀ = P _x + K _p × (α−γ) × ΔT (2)
P ₀ : Oxygen pressure P _x : Oxygen pressure calculated last time α: Oxygen gas generation amount γ: Oxygen gas decrease amount K _p : Predetermined constant (a constant for converting the oxygen gas amount in the battery 50 into oxygen pressure) .)

Here, when the first oxygen pressure P ₀ is calculated, the oxygen pressure (P _x ) calculated last time in the equation is set to a predetermined value (for example, atmospheric pressure or the like). Further, when calculating the first oxygen pressure P ₀ , the oxygen gas decrease amount (γ) is a map representing the relationship between the oxygen pressure in the battery 50 stored in advance in the ROM 74 and the oxygen gas decrease amount per unit time. Further, it is calculated by applying a predetermined value (for example, atmospheric pressure) as the oxygen pressure in the battery 50. When calculating the oxygen pressure P ₀ after ΔT, the oxygen gas decrease amount (γ) represents the relationship between the oxygen pressure in the battery 50 stored in advance in the ROM 74 and the oxygen gas decrease amount per unit time. The map is calculated by applying the previously calculated oxygen pressure (P _x ) as the oxygen pressure in the battery 50 to the map.

The amount of oxygen gas generated is calculated by the following equation (3) or (4).
α = (− IB) × β × K _α (3)
α = (− IB) × (1−η) × K _α (4)
α: Oxygen gas generation amount per unit time ΔT IB: Current of battery 50 (charge side is negative)
β, η: charging efficiency of the battery 50 K _α : a predetermined constant (which is appropriately selected depending on the unit of α. For example, when α is expressed in mol, the unit time ΔT should be 1 sec. For example, the reciprocal of the Faraday constant divided by 4.)

  The charging efficiency of the battery 50 in the above formula (3) or (4) is the ratio of the amount of electricity actually stored to the chargeable charge amount (η) or the ratio of the amount of electricity that could not be stored due to gas generation or the like. (Β = 1−η). For example, a map representing the relationship between the electromotive voltage (OCV) of the battery 50 and the charging efficiency is used to calculate the charging efficiency of the battery 50. The relationship between the electromotive voltage of the battery 50 and the charging efficiency depends on the temperature or current value of the battery 50. For example, when the temperature of the battery 50 is 40 ° C., 50 ° C., 60 ° C., etc. Prepare a map showing the relationship between the electromotive voltage and the charging efficiency at the time of the temperature of the battery 50, or, for example, when the current value of the battery 50 is 5A, 25A, 50A, etc. It is desirable to prepare a map that represents the relationship between the electromotive voltage and the charging efficiency when the battery 50 has a current value.

  From the oxygen gas generation amount and oxygen gas decrease amount calculated in this way, the oxygen pressure is calculated by the above equation (2). Then, the internal pressure in the battery 50 is estimated from the sum of the calculated oxygen pressure and the above-described equilibrium hydrogen pressure.

20 hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier, 35 reduction gear 40, motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 49 voltage sensor, 50 battery, 51 temperature sensor, 52 battery electronic control unit (battery ECU), 53 current sensor , 54 power line, 60 gear mechanism, 62 differential gear, 63a, 63b drive wheel, 70 hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 80 ignition switch, 81 shift lever, 2 shift position sensor, 83 accelerator pedal, 84 an accelerator pedal position sensor, 85 brake pedal, 86 a brake pedal position sensor, 88 vehicle speed sensor, MG1, MG2 motor.

Claims (2)

Target charge amount setting means for setting a target charge amount of the secondary battery based on a charge state of the secondary battery;
An electromotive voltage calculation means for calculating an electromotive voltage of the secondary battery based on a voltage between terminals of the secondary battery and a current value;
Voltage determining means for determining whether the electromotive voltage of the secondary battery is equal to or higher than a gas generation potential at which gas generation occurs in the secondary battery;
When the electromotive voltage of the secondary battery is greater than or equal to the gas generation potential, the target charge amount is limited, and when the electromotive voltage of the secondary battery is less than the gas generation potential, the target charge amount Control means for controlling the target charge amount so as to maintain or increase
An internal pressure estimating means for estimating an internal pressure of the secondary battery based on a voltage between terminals of the secondary battery, a current value, and a temperature;
An internal pressure determining means for determining whether the internal pressure of the secondary battery is equal to or greater than a predetermined value ,
The control means limits the target charge amount when the electromotive voltage of the secondary battery is equal to or higher than the gas generation potential and the internal pressure of the secondary battery is equal to or higher than a predetermined value. When the electromotive voltage is less than the gas generation potential or the internal pressure of the secondary battery is less than a predetermined value, the target charge amount is controlled so as to maintain or increase the target charge amount, and the controlled target charge amount And charging the secondary battery on the basis of the charge control device. The charge control device according to claim 1,
The control means limits the target charge amount, so that when the electromotive voltage of the secondary battery is less than the gas generation potential or the internal pressure of the secondary battery is less than a predetermined value, the target charge is performed. you and cancels the limitation of quantity charging control device.

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