JP4200956B2 - Battery control device for hybrid vehicle, battery control method for hybrid vehicle, and hybrid vehicle - Google Patents

Description

  The present invention relates to a hybrid vehicle battery control device mounted on a hybrid vehicle having an engine and a motor generator, a control method therefor, and a hybrid vehicle mounted with the control device. More specifically, the present invention relates to a hybrid vehicle battery control device, a hybrid vehicle battery control method, and a hybrid vehicle for controlling charge / discharge power according to the state and environment of the vehicle battery.

  There is a hybrid vehicle in which a motor generator and a secondary battery are mounted in addition to the engine, and a part of the vehicle driving force is obtained by the motor generator. This hybrid vehicle generally has an engine ECU that monitors the state of the engine and a battery ECU that monitors the state of the battery, and information from these is input to the vehicle ECU. The vehicle ECU receives information from the engine ECU and the battery ECU, controls the engine and the motor generator according to the driving operation of the driver, and controls the driving of the automobile.

  In general, it has been found that the secondary battery has an influence on the battery life when the input / output voltage exceeds a predetermined upper and lower limit voltage range. Therefore, in a secondary battery for a hybrid vehicle that requires a long life, charging / discharging that is outside the upper and lower limit voltage range is not performed. Furthermore, the allowable time during which continuous input / output is allowed is set to several seconds, for example. Further, in the secondary battery, it is not preferable that the battery temperature rises beyond a predetermined range. Therefore, conventionally, the maximum allowable input / output power value is set for the battery temperature and the state of charge (SOC) at that time (see, for example, Patent Document 1).

  This allowable input / output value is limited as shown in the graphs of FIGS. 6 and 7, for example. In these graphs, the region above the horizontal axis shows the case where the output value is positive, and the battery outputs power. The area below the horizontal axis shows a case where the battery is charged by regenerating surplus energy generated by the driver's braking operation or the like. First, the allowable input / output with respect to the battery temperature is limited within the range of the curve shown in FIG. Since the rate of chemical reactions in secondary batteries depends on temperature, both output and regenerative characteristics are greatly reduced, especially at low temperatures. For this reason, the allowable input / output values are limited at low temperatures to prevent voltage drop. In addition, when the temperature is higher than a predetermined temperature, the allowable input / output value is limited to suppress the battery reaction, and further increase of the battery temperature is suppressed.

  Further, the allowable input / output for the SOC is limited as shown in FIG. In a conventional hybrid vehicle, the center SOC is generally set as a predetermined constant value. The central SOC is set to, for example, about 50 to 60% so that regeneration and output can be sufficiently performed according to the driving operation of the driver. When the SOC falls below a predetermined range, the battery output is limited so that the SOC does not fall any further. In addition, when the SOC becomes higher than a predetermined range, no further charging is performed. In this way, the allowable input / output is limited according to the SOC so that the SOC is within a predetermined range.

When the vehicle is in use, the battery ECU obtains the battery temperature and SOC at that time, and obtains an allowable input / output value corresponding to each. Further, the smallest one of them is set as the allowable input / output value at that time, and is output to the vehicle ECU. The vehicle ECU controls the entire vehicle so that the battery is used within the allowable range. However, in the control by this method, as shown in the graphs of FIGS. 6 and 7, the allowable input / output values when the battery temperature is low are extremely small. On the other hand, a control method has been proposed in which the temperature of the battery and the outside air temperature are detected and the central SOC is changed accordingly (see, for example, Patent Document 2). According to this technique, the lower the battery temperature, the larger the center SOC is set, so that a necessary output can be obtained regardless of the temperature.
JP-A-11-187777 JP 2002-345165 A

  However, the battery control method described in Patent Document 2 is complicated in control and may be wasteful. On the other hand, in the control method described in Patent Document 1, as shown in FIG. 6, the allowable input / output value in a state where the battery temperature is low becomes very small. For this reason, motor assist and energy recovery during regeneration are reduced in winter, etc. in cold regions, leading to deterioration of fuel consumption as a whole vehicle. In particular, in a relatively short time driving such as commuting use, the driving is stopped before the battery temperature rises, so that there is a problem that a state of poor fuel consumption continues.

  On the other hand, it is not preferable to increase the upper / lower limit voltage and the allowable time in the entire region in order to increase the allowable input / output value at low temperature because the battery life may be shortened. In addition, there is a method of improving battery performance by increasing the number of cells and the capacity of the battery, but it is useless because energy is excessive at room temperature. Furthermore, there is a problem that it is not preferable because it leads to an increase in cost and weight.

  The present invention has been made to solve the problems of the conventional battery control method described above. That is, the problem is that the battery control device for a hybrid vehicle and the battery control for a hybrid vehicle that can improve the fuel efficiency at low temperature without changing the central SOC without affecting the life, cost and weight of the battery. It is to provide a method and a hybrid vehicle.

The battery control device for a hybrid vehicle of the present invention made for the purpose of solving this problem is a battery control device for a hybrid vehicle that controls charging / discharging of the battery of the hybrid vehicle. Set according to the temperature, set the upper limit voltage when the battery temperature is low and set the upper limit voltage to be higher than the upper limit voltage when the battery temperature is high, and set the lower limit voltage of the battery input / output voltage according to the battery temperature, Set the lower limit voltage setting section that sets the lower limit voltage when the battery temperature is low to the lower limit voltage when the battery temperature is high, and the allowable continuous input / output time of the battery according to the battery temperature, and allow when the battery temperature is low time and a permissible time setting unit to less than the allowable time when the battery temperature is high, the upper limit voltage is set by the upper limit voltage setting unit, and the lower limit voltage set lower limit voltage by the setter And it controls the charging and discharging of the battery within the permissible time allowable time set by the setting unit.

  According to the battery control apparatus for a hybrid vehicle of the present invention, the upper limit voltage setting unit and the lower limit voltage setting unit set the upper limit voltage and the lower limit voltage according to the battery temperature. In particular, when the battery temperature is low, the upper limit voltage is set to be higher than that when the battery temperature is high, and the lower limit voltage is set to be lower than that when the battery temperature is high. Therefore, a certain amount of charge / discharge is possible even when the battery temperature is low, and the allowable input / output value can be set larger than the conventional one. Therefore, it is possible to improve fuel efficiency at low temperatures without affecting the life, cost, and weight of the battery and without changing the central SOC.

Furthermore, in the present invention, since the allowable time for continuous input / output of the battery is set according to the battery temperature, even when the range of the upper limit voltage and the lower limit voltage is widened when the battery temperature is low, The output is limited by the allowable time. Therefore, there is no possibility of affecting the battery life.

  Here, regarding the input / output voltage, the output side is positive and the input side, that is, the charging side is negative. Therefore, the upper limit voltage is the maximum voltage that is allowed to be output from the battery. The lower limit voltage is a minimum voltage applied to charge the battery, and this is the maximum value on the input side as an absolute value. This upper and lower limit voltage affects the battery life, and it is not preferable to increase the range of the upper and lower limit voltage in the normal temperature range. However, at low temperatures, the upper and lower limit voltage ranges can be increased without affecting the battery life. As a result, the output power from the battery at a low temperature can be increased, and the fuel efficiency can be improved.

Furthermore, in the present invention, the upper limit voltage setting unit increases the upper limit voltage as the battery temperature is lower when the battery temperature is within the range between the first temperature and the second temperature, and the battery temperature is out of the range. In this case, it is desirable to keep the upper limit voltage constant.
In this way, the upper limit voltage is made constant, for example, in the normal temperature range or higher and in the extremely low temperature range. Further, in the low temperature region between them, the upper limit voltage is increased as the battery temperature is lower, so that the upper and lower limit voltage range is increased within a range that does not affect the battery life.

Further, in the present invention, when the battery temperature is within the range between the third temperature and the fourth temperature, the lower limit voltage setting unit lowers the lower limit voltage as the battery temperature is lower, and the battery temperature is out of the range. In this case, it is desirable to keep the lower limit voltage constant.
In this way, the lower limit voltage is made constant, for example, in the normal temperature range or higher and in the extremely low temperature range. Further, in the low temperature range between them, the lower limit voltage is lowered as the battery temperature is lower, so the range of the upper and lower limit voltages is increased within a range that does not affect the life of the battery. Here, the first temperature and the third temperature may be the same. Further, the second temperature and the fourth temperature may be the same.

Further, in the present invention, the allowable time setting unit is configured to make the allowable time constant when the battery temperature is higher than the fifth temperature, and shorten the allowable time as the battery temperature is lower when the battery temperature is lower than the fifth temperature. It is desirable that
In this way, for example, a certain allowable time is set in the normal temperature range or higher or in the low temperature range. Since the reaction rate is very slow in the extremely low temperature range, if the allowable time is set shorter as the battery temperature is lower, the effect on the battery life is very small and control is easy. Here, the fifth temperature may be the same as the first temperature or the third temperature.

Furthermore, in the present invention, the upper limit voltage setting unit, the lower limit voltage setting unit, and the allowable time setting unit set the upper and lower limit voltages and the allowable time according to the state of charge of the battery in addition to the battery temperature. The maximum input / output setting unit that sets the maximum input / output of the battery according to the state of charge, the upper limit voltage set by the upper limit voltage setting unit, the lower limit voltage set by the lower limit voltage setting unit, and the allowable time setting unit The upper / lower limit output setting unit that sets the upper / lower limit output of the battery according to the allowable time, and the maximum input / output set by the maximum input / output setting unit and the upper / lower limit output set by the upper / lower limit output setting unit It is desirable to control charging / discharging of the battery by the smaller one.
In this way, the maximum input / output power value allowed for the battery is appropriately controlled according to not only the battery temperature but also the state of charge of the battery.

  The present invention also relates to a hybrid vehicle battery control method for controlling charging / discharging of a hybrid vehicle battery, wherein the upper limit voltage of the input / output voltage of the battery is determined according to the battery temperature. Set the lower limit voltage of the battery input / output voltage to be higher than the upper limit voltage when the battery temperature is high, the lower limit voltage when the battery temperature is low, and the lower limit when the battery temperature is high according to the battery temperature. The present invention extends to a battery control method for a hybrid vehicle that is set to be equal to or lower than a voltage and controls charging / discharging of the battery within a range between the set upper limit voltage and the set lower limit voltage.

Furthermore, in the present invention, the allowable time for continuous input / output of the battery is set according to the battery temperature so that the allowable time when the battery temperature is low is less than the allowable time when the battery temperature is high. that controls charging and discharging of the battery within the upper limit voltage set lower limit voltage and the preset allowable time.

The present invention also provides a hybrid vehicle including a battery control device that controls the charge / discharge of a battery of the electric motor by using both the electric motor and the internal combustion engine for driving. Set the upper limit voltage according to the battery temperature, set the upper limit voltage when the battery temperature is low to the upper limit voltage when the battery temperature is high, and the lower limit voltage of the battery input / output voltage according to the battery temperature Set the lower limit voltage setting section that sets the lower limit voltage when the battery temperature is low to the lower limit voltage when the battery temperature is high, and the allowable continuous input / output time of the battery according to the battery temperature. and a permissible time setting unit for low allowable time when less time allowed when the battery temperature is high, the upper limit voltage set by the upper limit voltage setting unit, a lower limit voltage is set by the lower limit voltage setting unit, and When allowed Also extends to a hybrid vehicle for controlling the charging and discharging of the battery within a set permissible time by the setting unit.

  According to the hybrid vehicle battery control device, the hybrid vehicle battery control method, and the hybrid vehicle of the present invention, the fuel efficiency at low temperature is improved without changing the central SOC without affecting the life, cost, and weight of the battery. be able to.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best mode for embodying the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, the present invention is applied to a hybrid vehicle having an engine and a motor generator.

  The hybrid vehicle 1 of the present embodiment has a battery control device 2 and a drive control device 3 as shown in FIG. For this purpose, an HVECU 11 that controls the entire hybrid vehicle 1 and a battery ECU 12 that is the center of the battery control device 2 are provided, and the drive control device 3 has an engine ECU 13.

  In the battery control device 2, the battery 20 is monitored by the battery ECU 12 and connected to the motor generator 22 via the relay 21. A thermistor 23 for detecting the temperature of the battery 20 and a cooling system 24 for cooling are also provided. In the drive control device 3, the engine 30 is monitored by the engine ECU 13. Further, the driving operation device 31 is connected to the HVECU 11. Further, both the motor generator 22 and the engine 30 are connected to the wheels 33 via the transmission 32. Here, the driving operation device 31 is an accelerator pedal, a brake pedal, a shift lever, or the like.

  Here, the battery ECU 12 detects the voltage and current of the battery 20, calculates the SOC of the battery 20 from the integration, and outputs the SOC to the HVECU 11. Further, the temperature of the battery 20 is detected by the thermistor 23 and output to the HVECU 11. At this time, if it is determined that the temperature of the battery 20 is higher than the predetermined temperature, the battery ECU 12 operates the cooling system 24 to cool the battery 20. Further, the engine ECU 13 monitors the state of the engine 30 and outputs it to the HVECU 11. Further, the HVECU 11 receives outputs from the battery ECU 12 and the engine ECU 13 and controls the operation of the motor generator 22 and the engine 30 according to the operation of the driving operation device 31.

  Based on the control of the HVECU 11, the motor generator 22 outputs a driving force as an electric motor or charges the battery 20 as a generator. When the motor generator 22 functions as an electric motor and applies driving force to the wheels 33, electric power is supplied from the battery 20 to the motor generator 22 via the relay 21. Further, when the vehicle speed becomes excessive due to the driver's braking operation or the like, the battery 20 is charged with surplus power obtained by regeneration by the motor generator 22.

  In addition, the hybrid vehicle 1 can receive a driving force from either the motor generator 22 or the engine 30 or both by switching the transmission 32. Therefore, if the driving force from the motor generator 22 can be used as much as possible, the fuel efficiency of the hybrid vehicle 1 can be improved accordingly. In this embodiment, the output lowering of the battery 20 in the low temperature range is suppressed by widening the upper and lower limit voltage range of the battery 20 in the low temperature range.

  In general, it has been found that charging / discharging over the upper and lower limit voltage in a secondary battery shortens the life of the battery 20. However, the present inventor has found that in a low temperature environment, even if the operation is performed slightly outside the upper and lower limit voltage range at room temperature, the life of the battery 20 is not adversely affected. Therefore, in the battery control device 2 of the present embodiment, the upper and lower limit voltages of the battery 20 are changed according to the temperature. That is, when the temperature of the battery 20 is low, the upper limit voltage is increased and the lower limit voltage is decreased as the temperature decreases. On the other hand, when the temperature of the battery 20 is equal to or higher than the normal temperature, the upper and lower limit voltages are set to the same constant values as in the prior art.

  In the battery control device 2 of the present embodiment, for example, as shown in FIG. 2, the upper and lower limit voltage values are changed according to the battery temperature. In this figure, the lower limit voltage shown in the lower graph corresponds to the minimum voltage at the time of input. The upper limit voltage shown in the upper graph corresponds to the maximum voltage at the time of output. As shown in this figure, at the battery temperature T1 or higher, the upper and lower limit voltages are both constant. These are the same values as before. On the other hand, at the low temperature of the battery temperatures T1 to T2, the lower the temperature, the higher the upper limit voltage value is changed and the lower limit voltage value is changed. At extremely low temperatures below the battery temperature T2, the upper and lower limit voltages are again set to constant values. Here, T1 corresponds to the first temperature and the third temperature, and T2 corresponds to the second temperature and the fourth temperature.

For example, the lower limit voltage Vlc at the time of input at a low temperature of the battery temperature T1 to T2 is expressed by the following equation using a constant α and a variable T depending on the temperature, where the lower limit voltage at room temperature is Vl. .
Vlc = Vl-αT
Further, the upper limit voltage Vuc at the time of output at a low temperature of the battery temperature T1 to T2 is expressed by the following equation using the constant β and the variable T depending on the temperature, where the upper limit voltage at room temperature is Vu. .
Vuc = Vu + βT
At an extremely low temperature equal to or lower than the battery temperature T2, Vlc and Vuc when the temperature is set to T2 in the above equations are the upper and lower limit voltages.

  Furthermore, in the battery control device 2 of the present embodiment, as shown in FIG. 3, the continuous permissible time is changed according to the battery temperature. This is the time during which charging / discharging at the above upper and lower limit voltages is continuously performed. Generally, the continuous permissible time at room temperature is set to a constant value such as several seconds. In this embodiment, the continuous allowable time is changed according to the battery temperature at an extremely low temperature equal to or lower than the battery temperature T2. Specifically, the lower the temperature, the shorter the setting. And it is not allowed at all below a predetermined temperature T3. Here, T2 corresponds to the fifth temperature.

For example, the allowable time t1c at the time of output at an extremely low temperature equal to or lower than the battery temperature T2 is expressed as the following equation using the constant γ and the temperature-dependent variable T, where the maximum allowable output time at room temperature is t1. Is done.
t1c = t1 / γT
Further, the allowable time t2c at the time of input at an extremely low temperature equal to or lower than the battery temperature T2 is similarly expressed by the following equation, where the maximum allowable input time at room temperature is t2.
t2c = t2 / γT
The variable T here becomes larger as the temperature is lower. The battery temperatures T1, T2, and T3 may be, for example, T1 of about 20 ° C., T2 of about −10 ° C., T3 of about −30 ° C., and the like.

  Next, a method for determining the degree to which the upper and lower limit voltages of the battery 20 are changed for each hybrid vehicle 1 will be described. Since the upper and lower limit voltages of the battery 20 vary depending on various conditions, a range that does not affect the battery life is obtained by experiments. As various preconditions, the specifications of the battery 20 and how the battery is used in the vehicle are greatly affected. First, the specifications of the battery 20 vary greatly depending on whether the type of the battery 20 is a lithium ion battery or a nickel metal hydride battery. Further, the characteristics of the battery 20 also differ depending on the materials such as active materials, electrolytes, additives, etc. used in the battery 20 and differences in internal structure. In addition, how the battery 20 is used in the vehicle varies depending on the vehicle type and the like, and the setting differs depending on this.

  First, the characteristics of the battery 20 are tested. As described above, an appropriate battery 20 is selected, and a maximum pulse endurance test is performed on the selected battery 20 at a voltage value larger than the conventional upper limit voltage at each temperature. Perform this test a number of times at different temperatures and upper and lower limit voltages to confirm the inflection point. If there is an inflection point, the deterioration starts clearly from there, so that the life is set, and those without an inflection point are considered to have a long life. Therefore, the upper and lower limit voltages at each temperature are set within a range where there is no inflection point.

  Conventionally, the allowable time for allowing continuous charge / discharge is set to a constant value. However, when the temperature is lower than the extremely low temperature, it is difficult to continuously charge and discharge for the conventional permissible time with the upper and lower limit voltages set here. Therefore, the allowable continuous time for continuous charge / discharge at extremely low temperatures is confirmed. The maximum pulse endurance test at each cryogenic temperature is further carried out with the confirmed allowable time. Then check the impact level on the service life. As a result, the allowable time for each temperature is set within a range where it is recognized that there is no effect on the service life. In this way, the upper and lower limit voltages and the allowable time as the characteristics of the battery 20 are determined.

  On the other hand, it is necessary to check the usage status of the battery 20 in an actual vehicle. Therefore, the input / output frequency and voltage level of the battery 20 in design are determined for various vehicles. Then, considering how the vehicle is used in cold or extremely hot areas, the conditions for the required life are determined. The upper and lower limit voltages are set so as to satisfy this necessary life with a margin.

  Thereby, the change graph of the upper and lower limit voltage in this vehicle is obtained as shown in FIG. 2, for example. Further, the allowable time is obtained as shown in FIG. 3, for example. When the temperature of the battery 20 is low, the resistance increases, so even if the output voltage is increased, the current does not increase excessively and the life is hardly affected. Therefore, by setting in this way, the allowable input / output values in the low temperature region can be expanded as shown in FIG. In this figure, the conventional permissible input / output values are indicated by broken lines, and the permissible input / output values of the present embodiment indicated by solid lines are greatly widened in the low temperature region. Accordingly, it is possible to increase the output of the battery 20 at a low temperature or a very low temperature, and to suppress deterioration of fuel consumption in winter.

  These graphs are determined for each SOC. That is, as a whole, a ternary map in which the SOC axis is added to these graphs is created. Then, the battery ECU 12 obtains the SOC and the temperature of the battery 20 at that time, extracts the upper and lower limit voltages from the compatible graph, and outputs them to the HVECU 11. In this embodiment, the center SOC may be set to a predetermined constant value.

  Furthermore, at a very low temperature, it is possible to take a method in which the performance of the battery 20 is left without setting an allowable time. This is because, at extremely low temperatures, the effect of continuous input and output on the life is small if it is within the upper and lower limit voltage range. In this case, however, control by the HVECU 11 is somewhat difficult. This is because the battery resistance greatly increases at extremely low temperatures, and a rapid output drop is likely to occur. If the engine 30 cannot cope with such a decrease in output, the acceleration behavior of the vehicle may be felt unsmoothly. That is, the driver may feel that there is a time lag between the accelerator operation and acceleration. In order to avoid this, it is necessary to speed up the control of the HVECU 11 so that it can quickly cope with a decrease in the output of the battery 20.

  Thus, in the hybrid vehicle 1 equipped with the battery control device 2 in which the upper and lower limit voltages and the allowable time are set, the output / regeneration control of the battery 20 is performed according to the flowchart shown in FIG. First, in the battery ECU 12, the thermistor 23 detects the temperature of the battery 20 (S101). Next, upper and lower limit voltages suitable for the temperature are acquired (S102). In addition, it is determined whether or not the temperature of the battery 20 is in a very low temperature region below a predetermined temperature (S103).

  When it is determined that it is not in the extremely low temperature region (S103: No), the same allowable time (t1, t2) as that in the normal temperature region is selected (S104). If it is determined that the temperature is in the extremely low temperature range (S103: Yes), an allowable time (t1c, t2c) corresponding to the temperature is selected (S105). Further, an allowable input / output value at that time is obtained from the upper and lower limit voltages and the allowable time (S106).

  The battery ECU 12 also detects the SOC of the battery 20 at that time (S107). An allowable input / output value corresponding to the SOC is obtained from the result (S108). Next, the two allowable input / output values obtained in S106 and S108 are compared (S109). The smaller one of them is adopted as the allowable input / output value at that time, and is output to the HVECU 11 (S110). The HVECU 11 controls the motor generator 22 according to the driving operation of the driver with the input allowable input / output value as a limit.

  As described above in detail, according to the battery control device 2 of the present embodiment, in the region where the temperature of the battery 20 is low, the upper limit voltage of input / output is increased and the lower limit voltage is decreased as the temperature decreases. Therefore, the output power in the low temperature region can be increased as compared with the conventional case. In this method, since the central SOC is not changed, the control is easy, and the number of cells of the battery 20 is not increased, so that the cost and weight are not increased. In addition, since the upper and lower limit voltage values in a range that does not affect the lifetime are determined by experiments, the lifetime of the battery 20 is not shortened. Accordingly, it is possible to improve fuel efficiency at low temperatures without affecting the life, cost, and weight of the battery 20 and without changing the central SOC. Furthermore, if the allowable time for the upper and lower limit voltages at extremely low temperatures is set, the control becomes easier.

In addition, this form is only a mere illustration and does not limit this invention at all. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof.
For example, each graph is an example, and an actual vehicle does not always have this shape.

It is a block diagram which shows schematic structure of the system of this form. It is a graph which shows the relationship between the battery temperature of this form, and an upper / lower limit voltage value. It is a graph which shows the relationship between the battery temperature of this form, and permissible time. It is a graph which shows the relationship between the battery temperature of this form, and an allowable input / output value. It is a flowchart which shows the control method of the hybrid vehicle of this form. It is a graph which shows the relationship between the conventional battery temperature and an allowable input / output value. It is a graph which shows the relationship between conventional SOC and permissible input / output value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 2 Battery control apparatus (Battery control apparatus for hybrid vehicles)
12 Battery ECU (Upper limit voltage setting unit, lower limit voltage setting unit, allowable time setting unit, maximum input / output setting unit, upper / lower limit output setting unit)
20 battery 22 motor generator (electric motor)
30 engine (internal combustion engine)

Claims (6)

In a hybrid vehicle battery controller for controlling the charge and discharge of a hybrid vehicle battery,
An upper limit voltage setting unit that sets the upper limit voltage of the battery input / output voltage according to the battery temperature, and sets the upper limit voltage when the battery temperature is low to be equal to or higher than the upper limit voltage when the battery temperature is high;
A lower limit voltage setting unit that sets the lower limit voltage of the battery input / output voltage according to the battery temperature, and sets the lower limit voltage when the battery temperature is low to the lower limit voltage when the battery temperature is high ;
An allowable time setting unit that sets the allowable time for continuous input / output of the battery according to the battery temperature, and sets the allowable time when the battery temperature is low to the allowable time when the battery temperature is high ,
Upper limit voltage set by the upper limit voltage setting unit, the lower limit voltage set by pre Symbol lower limit voltage setting unit, and to control the charging and discharging of the battery within a set permissible time by the allowable time setting unit A battery control device for a hybrid vehicle characterized by the above. In the hybrid vehicle battery control device according to claim 1 ,
The upper limit voltage setting unit increases the upper limit voltage as the battery temperature is lower when the battery temperature is within the range between the first temperature and the second temperature, and the upper limit when the battery temperature is out of the range. The voltage is constant,
The lower limit voltage setting unit lowers the lower limit voltage as the battery temperature is lower when the battery temperature is within the range between the third temperature and the fourth temperature, and the lower limit when the battery temperature is out of the range. A battery control apparatus for a hybrid vehicle characterized in that the voltage is constant. In the hybrid vehicle battery control device according to claim 1 or 2,
The allowable time setting unit sets the allowable time constant when the battery temperature is higher than the fifth temperature, and shortens the allowable time as the battery temperature is lower when the battery temperature is lower than the fifth temperature. A battery control device for a hybrid vehicle characterized by the above. In the hybrid vehicle battery control device according to any one of claims 1 to 3 ,
The upper limit voltage setting unit, the lower limit voltage setting unit, and the allowable time setting unit set the upper and lower limit voltage and the allowable time according to the state of charge of the battery in addition to the battery temperature,
A maximum input / output setting unit that sets the maximum input / output of the battery according to the state of charge of the battery;
Upper / lower limit output setting unit for setting the upper / lower limit output of the battery according to the upper limit voltage set by the upper limit voltage setting unit, the lower limit voltage set by the lower limit voltage setting unit, and the allowable time set by the allowable time setting unit And
A battery for hybrid vehicles, wherein charge / discharge of the battery is controlled by a smaller one of the maximum input / output set by the maximum input / output setting unit and the upper / lower limit output set by the upper / lower limit output setting unit Control device. In a hybrid vehicle battery control method for controlling charge and discharge of a hybrid vehicle battery,
The upper limit voltage of the battery input / output voltage is set according to the battery temperature so that the upper limit voltage when the battery temperature is low is equal to or higher than the upper limit voltage when the battery temperature is high.
Set the lower limit voltage of the battery input / output voltage according to the battery temperature so that the lower limit voltage when the battery temperature is low is less than or equal to the lower limit voltage when the battery temperature is high.
The allowable time for continuous battery input / output is set according to the battery temperature so that the allowable time when the battery temperature is low is less than the allowable time when the battery temperature is high,
A battery control method for a hybrid vehicle, wherein charge / discharge of the battery is controlled within a range of a set upper limit voltage, a set lower limit voltage, and a set allowable time . In a hybrid vehicle equipped with a battery control device that uses an electric motor and an internal combustion engine for driving and controls charging / discharging of the battery of the electric motor, the battery control device includes:
An upper limit voltage setting unit that sets the upper limit voltage of the battery input / output voltage according to the battery temperature, and sets the upper limit voltage when the battery temperature is low to be equal to or higher than the upper limit voltage when the battery temperature is high;
A lower limit voltage setting unit that sets the lower limit voltage of the battery input / output voltage according to the battery temperature, and sets the lower limit voltage when the battery temperature is low to the lower limit voltage when the battery temperature is high ;
An allowable time setting unit that sets the allowable time for continuous input / output of the battery according to the battery temperature, and sets the allowable time when the battery temperature is low to the allowable time when the battery temperature is high ,
Upper limit voltage set by the upper limit voltage setting unit, the lower limit voltage set by pre Symbol lower limit voltage setting unit, and to control the charging and discharging of the battery within a set permissible time by the allowable time setting unit A featured hybrid car.

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