Patent Description:
A known hybrid automobile includes an engine and a motor generator, which are drive sources. In the hybrid automobile, fuel economy can be improved by driving the motor generator as a motor and assisting the engine when the engine combustion efficiency is low (for example, when the automobile is started). In the battery that supplies such a motor generator with power, thermal degradation tends to progress easily as the battery temperature (the temperature of the battery) becomes excessively high. Thus, <CIT> discloses an example of a technique of curbing an excessive rise in the battery temperature by limiting the output of the motor generator, i.e., by limiting charging/discharging of the battery, when the battery temperature is greater than or equal to a predetermined limit temperature.

A travel control device of a hybrid electric automobile is furthermore disclosed by <CIT>. According to this travel control device, when a descending road is predicted ahead of a vehicle, a control range of an SOC of a battery is enlarged at a point before the descending road. While the vehicle is traveling until it reaches the descending road, the SOC of the battery is lowered to a lower limit SOCloex of the enlarged control range through power running control of a motor. While the vehicle is traveling the descending road thereafter, the SOC is raised to an upper limit SOCupex of the enlarged control range through regenerative control of the motor. Within the enlarged region on the side of the lower limit, a current to be fed to the motor is suppressed. Within an expansion domain on the side of the upper limit, a current to be generated by the motor is suppressed. Thus, the raising and lowering of the SOC are moderated in order to prevent deterioration of the battery.

The method described in <CIT> is capable of curbing an excessive rise in the battery temperature. However, ensuring the charge/discharge amount of the battery becomes difficult when charging/discharging is limited due to the battery temperature. This may worsen the fuel economy.

It is an objective of the present invention to provide a charging/discharging control device capable of ensuring the charge/discharge amount of a battery while curbing a rise in the battery temperature.

An aspect of the present invention provides a charging/discharging control device configured to control charging and discharging of a battery installed in a hybrid vehicle that includes a motor generator. The motor generator is a power source. The charging/discharging control device includes a route information acquisition unit configured to acquire a planned travel route, a start point of the planned travel route being a current position, a section identification unit configured to estimate a change in a state of charge of the battery using a change in potential energy on the planned travel route and identify an excessive discharging section and an excessive charging section on the planned travel route, and a charging/discharging control unit configured to control charging and discharging of the battery by controlling an output of the motor generator. The excessive charging section includes a section where the state of charge continues to rise to a maximum state of charge and is then maintained at the maximum state of charge. The excessive discharging section includes a section where the state of charge continues to fall to a minimum state of charge and is then maintained at the minimum state of charge. The charging/discharging control unit is configured to limit a charge current value in the excessive charging section to a fixed first upper limit value. The first upper limit value is set such that the state of charge reaches the maximum state of charge at an end point of the excessive charging section when the charge current value in the excessive charging section is maintained at the first upper limit value. The charging/discharging control unit is further configured to limit a discharge current value in the excessive discharging section to a fixed second upper limit value, wherein the second upper limit value is set such that the state of charge reaches the minimum state of charge at an end point of the excessive discharging section when the discharge current value in the excessive discharging section is maintained at the second upper limit value.

A charging/discharging control device according to an embodiment will now be described with reference to <FIG>.

As shown in <FIG>, a vehicle <NUM>, which is a hybrid automobile, includes an engine <NUM> and a motor generator <NUM> (hereinafter referred to as M/G <NUM>), which are power sources. A rotary shaft <NUM> of the engine <NUM> and a rotary shaft <NUM> of the M/G <NUM> are connected to each other such that they can be disconnected by a clutch <NUM>. The rotary shaft <NUM> of the M/G <NUM> is connected to drive wheels <NUM> via, for example, a transmission <NUM> and a drive shaft <NUM>.

The engine <NUM> is, for example, a diesel engine with multiple cylinders. When fuel burns in each cylinder, torque is generated to rotate the rotary shaft <NUM>. When the clutch <NUM> is connected, the torque generated by the engine <NUM> is transmitted to the drive wheels <NUM> via the rotary shaft <NUM> of the M/G12, the transmission <NUM>, and the drive shaft <NUM>.

The M/G <NUM> is electrically connected to a battery <NUM> via an inverter <NUM>. The battery <NUM> is a rechargeable battery capable of being charged and discharged. The battery <NUM> includes multiple cells that are electrically connected to one another. When supplied with the power stored in the battery <NUM> via the inverter <NUM>, the M/G <NUM> functions as a motor that assists the engine <NUM> by rotating the rotary shaft <NUM>. When the M/G <NUM> functions as a motor, the M/G <NUM> generates a motor torque Tm. The motor torque Tm is transmitted to the drive wheels <NUM> through the transmission <NUM> and the drive shaft <NUM>. Further, the M/G <NUM> functions as a generator that stores, in the battery <NUM> via the inverter <NUM>, the power generated using the rotation of the rotary shaft <NUM> when, for example, the accelerator is off. The braking torque generated when the M/G <NUM> functions as a generator is a regenerative torque Tr.

The transmission <NUM> changes the torque of the rotary shaft <NUM> of the M/G <NUM> and transmits the new torque to the drive wheels <NUM> through the drive shaft <NUM>. The transmission <NUM> is capable of setting multiple gear ratios Rt.

When the M/G <NUM> functions as a motor, the inverter <NUM> converts the direct-current voltage from the battery <NUM> into alternating-current voltage to supply the M/G <NUM> with power. When the M/G <NUM> functions as a generator, the inverter <NUM> converts the alternating-current voltage from the M/G <NUM> into direct-current voltage to supply the battery <NUM> with power and charge the battery <NUM>.

The vehicle <NUM> includes a high-voltage circuit having the M/G <NUM>, the inverter <NUM>, and the battery <NUM>, which are high-voltage components. In the following description, the current flowing into the battery <NUM> when power is supplied from the inverter <NUM> to the M/G <NUM> is referred to as the discharge current, and the current flowing into the battery <NUM> when power is supplied from the inverter <NUM> to the battery <NUM> is referred to as the charge current.

The above-described engine <NUM>, clutch <NUM>, inverter <NUM>, transmission <NUM>, and the like are controlled by a control device <NUM>. The control device <NUM> controls the vehicle <NUM> in an integrated manner.

The control device <NUM> includes, for example, a hybrid ECU <NUM>, an engine ECU <NUM>, an inverter ECU <NUM>, a battery ECU <NUM>, a transmission ECU <NUM>, and an information ECU <NUM>. The ECUs <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> are connected to one another by, for example, a control area network (CAN).

The electronic control units (ECUs) <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> mainly include a microcomputer in which a processor, a memory, an input interface, an output interface, and the like are connected to one another by a bus. The ECUs <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> acquire state information, which relates to the state of the vehicle <NUM>, via the input interface and executes various processes using the acquired state information and using a control program and various types of data stored in the memory.

The hybrid ECU <NUM> acquires, through the input interface, various types of the state information output by the ECUs <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. For example, the hybrid ECU <NUM> uses a signal from the engine ECU <NUM> to acquire a requested torque Tdrv from the driver and an engine rotation speed Ne, which is the rotation speed of the rotary shaft <NUM> of the engine <NUM>. The hybrid ECU <NUM> uses a signal from the inverter ECU <NUM> to acquire a motor rotation speed Nm, which is the rotation speed of the rotary shaft <NUM> of the M/G <NUM>. The hybrid ECU <NUM> uses a signal from the battery ECU <NUM> to acquire a battery voltage and a state of charge SOC of the battery <NUM>. The hybrid ECU <NUM> uses a signal from the transmission ECU <NUM> to acquire, for example, disconnection state information of the clutch <NUM> and the gear ratio Rt in the transmission <NUM>. The hybrid ECU <NUM> uses a signal from the information ECU <NUM> to acquire, for example, a vehicle speed v and route information.

The hybrid ECU <NUM> uses the acquired information to generate various control signals and output the generated control signals to the ECUs <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> via the output interface. The hybrid ECU <NUM> calculates an engine command torque Teref, which is a command torque to the engine <NUM>, and outputs to the engine ECU <NUM> a control signal indicating the calculated engine command torque Teref. The hybrid ECU <NUM> calculates a motor command torque Tmref, which is a command torque to the M/G <NUM>, and outputs to the inverter ECU <NUM> a control signal indicating the calculated motor command torque Tmref. The hybrid ECU <NUM> outputs to the transmission ECU <NUM> a control signal commanding the disconnection of the clutch <NUM> and a control signal commanding the gear ratio Rt in the transmission <NUM>.

The engine ECU <NUM> acquires the engine rotation speed Ne and an accelerator operation amount ACC of an accelerator pedal <NUM>, and controls, for example, a fuel injection amount and an injection timing such that the torque corresponding to an amount of the engine command torque Teref that has been input from the hybrid ECU <NUM> acts on the rotary shaft <NUM>. The engine ECU <NUM> uses, for example, the accelerator operation amount ACC and the engine rotation speed Ne to calculate the requested torque Tdrv from the driver and output the calculated requested torque Tdrv to the hybrid ECU <NUM>.

The inverter ECU <NUM> acquires the motor rotation speed Nm, and controls the inverter <NUM> such that the torque corresponding to an amount of the motor command torque Tmref that has been input from the hybrid ECU <NUM> acts on the rotary shaft <NUM>.

The battery ECU <NUM> monitors a charge/discharge current I of the battery <NUM> and calculates the state of charge SOC of the battery <NUM> using an integration value of the charge/discharge current I. In addition to the charge/discharge current I of the battery <NUM>, the battery ECU <NUM> acquires the battery voltage.

The transmission ECU <NUM> controls the disconnection of the clutch <NUM> in response to a request of disconnecting the clutch <NUM> from the hybrid ECU <NUM>. Further, the transmission ECU <NUM> controls the gear ratio Rt of the transmission <NUM> using a control signal that indicates the gear ratio Rt from the hybrid ECU <NUM>.

The information ECU <NUM> acquires various types of information using signals from various sensors, which are the components of an information acquisition unit <NUM>, and outputs the acquired information to the hybrid ECU <NUM>. For example, the information ECU <NUM> acquires the vehicle speed v of the vehicle <NUM> that is based on a signal from a vehicle speed sensor and outputs the acquired vehicle speed v to the hybrid ECU <NUM>.

In addition, the information ECU <NUM> acquires the route information, which includes current position information and section information. The current position information indicates the current position of the vehicle <NUM>. The section information relates to the sections of a planned travel route where the vehicle <NUM> is planned to travel from the current position. The planned travel route is acquired in a range of, for example, several km to several tens of km.

The information acquisition unit <NUM> includes a route information generator <NUM>, which is, for example, a locator device or a car navigation device, as a device related to the route information. Such a locator device or car navigation device includes road position information, altitude information, and map information. In the road position information, the coordinates of each position in the road are defined. In the altitude information, the altitude of each position is defined. The map information is related to, for example, classification information in which the classification of a road such as a highway is defined for each position in the road.

The locator device acquires the current position information, which indicates the current position of the vehicle <NUM> through a satellite positioning system. The locator device sets the planned travel route using the current position information and the map information to generate the section information related to the set planned travel route.

The car navigation device acquires the current position information, which indicates the current position of the vehicle <NUM> through the satellite positioning system. The car navigation device sets, as a planned travel route, for example, the route to a destination that has been set by the driver and generates the section information related to the planned travel route.

As shown in <FIG>, when the planned travel route is set, the route information includes the current position information, which is shown in <FIG>, and the section information, which is shown in <FIG>.

As shown in <FIG>, the current position information includes a current position P0, an altitude H0 of the current position P0, and its classification. The section that connects nodes is referred to as the unit section. As shown in <FIG>, the section information includes, for example, an end position Pk of the unit section, an altitude Hk, a section length Lk, a gradient value θk (k is an integer greater than or equal to <NUM>), and classification.

The hybrid ECU <NUM> uses various types of information that has been input from the information ECU <NUM> to execute a high-speed traveling charge/discharge control. The high-speed traveling charge/discharge control is a charge/discharge control of the battery <NUM> performed when the vehicle <NUM> is traveling on a highway at a high speed.

The hybrid ECU <NUM> includes various functional units that function when various programs related to the high-speed traveling charge/discharge control are executed. That is, the hybrid ECU <NUM> includes an acquisition unit <NUM>, a weight calculation unit <NUM>, a control selection unit <NUM>, a travel resistance setting unit <NUM>, a section identification unit <NUM>, and a torque control unit <NUM>.

The acquisition unit <NUM> corresponds to a route information acquisition unit. The acquisition unit <NUM> acquires the vehicle speed v in addition to the route information that has been output by the information ECU <NUM>. Further, the acquisition unit <NUM> acquires the accelerator operation amount ACC, the engine rotation speed Ne, and the gear ratio Rt in the transmission <NUM>.

The weight calculation unit <NUM> calculates a weight W of the vehicle <NUM>. The weight calculation unit <NUM> calculates the weight W of the vehicle <NUM> using, for example, the accelerator operation amount ACC, the engine rotation speed Ne, the vehicle speed v, and the gear ratio Rt in the transmission <NUM>.

The control selection unit <NUM> uses various types of information acquired by the acquisition unit <NUM> to select a control mode of outputting the M/G <NUM>. In a case where the vehicle <NUM> is traveling at a high speed on a highway (for example, the vehicle speed is greater than or equal to <NUM>/h), the control selection unit <NUM> uses the route information and the vehicle speed v to select a temperature rise curbing control. In other cases, the control selection unit <NUM> selects a normal control.

The travel resistance setting unit <NUM> sets a travel resistance for each unit section in the section information. The travel resistance setting unit <NUM> sets the travel resistance for each section by taking into account the air resistance corresponding to the shape of a vehicle relative to, for example, a gradient resistance that is based on the gradient value θk of each section and a rolling resistance that is based on the classification of a road.

The section identification unit <NUM> estimates the changes in the state of charge SOC in the planned travel route and identifies an excessive discharging section Td and an excessive charging section Tc.

The section identification unit <NUM> estimates the changes in the state of charge SOC by hypothesizing that the vehicle <NUM> having the weight W does high-speed traveling on the planned travel route at a fixed vehicle speed v. The section identification unit <NUM> estimates the changes in the state of charge SOC of the battery <NUM> on the planned travel route by taking into account, relative to a change in potential energy based on the weight W and the altitude differences between sections, a resistance loss based on the vehicle speed v, a resistance loss based on the travel resistance, a resistance loss based on a section length, conversion efficiencies of the M/G <NUM> and the inverter <NUM>, and the like. Further, the section identification unit <NUM> uses the changes in the state of charge SOC to set the excessive charging section Tc and the excessive discharging section Td in the planned travel route.

The excessive charging section Tc includes a rising section where the state of charge SOC rises from a minimum state of charge SOC1 to a maximum state of charge SOC2 and a maximum maintenance section where the state of charge SOC is maintained at the maximum state of charge SOC2. For example, as shown in <FIG>, the excessive charging section Tc includes a continuously rising continuously rising section <NUM> and a maximum maintenance section <NUM>, which follows the continuously rising section <NUM>. In the continuously rising section <NUM>, the state of charge SOC continues to rise to the maximum state of charge SOC2. In the maximum maintenance section <NUM>, the state of charge SOC is maintained at the maximum state of charge SOC2. Further, for example, as shown in <FIG>, the excessive charging section Tc includes a temporal discharging section <NUM> during a rising section <NUM>. In the temporal discharging section <NUM>, the state of charge SOC never reaches the minimum state of charge SOC1. The excessive charging section Tc also includes a temporal discharging section <NUM> in a maximum maintenance section <NUM>. In the temporal discharging section <NUM>, the state of charge SOC never reaches the minimum state of charge SOC1.

The excessive discharging section Td includes a falling section where the state of charge SOC falls from the maximum state of charge SOC2 to the minimum state of charge SOC1 and a minimum maintenance section where the state of charge SOC is maintained at the minimum state of charge SOC1. For example, as shown in <FIG>, the excessive discharging section Td includes a continuously falling section <NUM> and a minimum maintenance section <NUM>, which follows the continuously falling section <NUM>. In the continuously falling section <NUM>, the state of charge SOC continues to fall to the minimum state of charge SOC1. In the minimum maintenance section <NUM>, the state of charge SOC is maintained at the minimum state of charge SOC1. Further, for example, as shown in <FIG>, the excessive discharging section Td includes a temporal charging section <NUM> during a falling section <NUM>. In the temporal charging section <NUM>, the state of charge SOC never reaches the maximum state of charge SOC2. The excessive discharging section Td also includes a temporal charging section <NUM> in a minimum maintenance section <NUM>. In the temporal charging section <NUM>, the state of charge SOC never reaches the maximum state of charge SOC2.

The torque control unit <NUM> corresponds to a charging/discharging control unit. The torque control unit <NUM> controls charging and discharging of the battery <NUM> by controlling the output of the M/G <NUM>. In a case where the vehicle <NUM> is traveling at a high speed on a highway, the torque control unit <NUM> uses the route information and the vehicle speed v to execute the temperature rise curbing control. In other cases, the torque control unit <NUM> executes the normal control. In the normal control, the torque control unit <NUM> controls the motor command torque Tmref in correspondence with the present travel state to follow a change in the potential energy such that the fuel economy becomes the highest for the motor torque Tm and such that the state of charge SOC reaches the maximum state of charge SOC2 in the shortest time for the regenerative torque Tr.

In the temperature rise curbing control, the torque control unit <NUM> controls the output of the M/G <NUM> by setting a first upper limit value for the excessive charging section Tc. The first upper limit value is a fixed charge current value. When the charge current value is maintained at the first upper limit value, the first upper limit value is set such that the state of charge SOC reaches the maximum state of charge SOC2 at the end point of the excessive charging section Tc. Further, the torque control unit <NUM> controls the output of the M/G <NUM> by setting a second upper limit value for the excessive discharging section Td. The second upper limit value is a fixed discharge current value. When the discharge current value is maintained at the second upper limit value, the second upper limit value is set such that the state of charge SOC reaches the minimum state of charge SOC1 at the end point of the excessive discharging section Td.

An example of the temperature rise curbing control will now be described with reference to <FIG> and <FIG>. First, the changes in the battery temperature that occur when the output of the M/G <NUM> is controlled with the normal control will be described with reference to <FIG>. As described above, in the normal control, the output of the M/G <NUM> is controlled so as to follow a change in the potential energy of the vehicle <NUM>.

As shown in the first section in <FIG>, the altitude H changes on the planned travel route (current position P0 to position P6), which is shown in the route information acquired by the acquisition unit <NUM>. In this case, the state of charge SOC changes in correspondence with a change in, for example, the potential energy. As shown in the second section in <FIG>, the state of charge SOC is maintained at the minimum state of charge SOC1 in the minimum maintenance sections (position P1 to position P2 and position P5 to position P6) and maintained at the maximum state of charge SOC2 in the maximum maintenance section (position P3 to position P4). This is because the motor torque Tm of the M/G <NUM> is controlled for discharging such that the fuel economy becomes the highest in correspondence with the present travel state. This is also because the regenerative torque Tr of the M/G <NUM> is controlled for charging such that the state of charge SOC reaches the maximum state of charge SOC2 in the shortest time. In such a normal control, as shown in the third section in <FIG>, discharging or charging is stopped after a large discharge current or charge current flows into the battery <NUM> in a short time. In the battery <NUM>, the amount of heat generation resulting from the internal resistance is proportional to the square of current. Thus, as shown in the fourth section in <FIG>, a battery temperature TmpB exponentially rises and then gradually falls. As a result, the maximum temperature and the average temperature of the battery <NUM> become high.

As shown in <FIG>, when the output of the M/G <NUM> is controlled with the temperature rise curbing control, for the planned travel route shown in the first section in <FIG>, the section identification unit <NUM> sets the section from the current position P0 (start point) to position P2 (end point) as an excessive discharging section Td1, sets the section from position P2 (start point) to position P4 (end point) as an excessive charging section Tc1, and sets the section from position P4 (start point) to position P6 (end point) as an excessive discharging section Td2.

As shown in the second and third sections in <FIG>, the torque control unit <NUM> controls the output of the M/G <NUM> by setting upper limit values (fixed discharge current values Id1 and Id2) for the excessive discharging sections Td1 and Td2. When the discharge current value is maintained at the upper limit value, the state of charge SOC changes at a fixed change rate from the start point (P0, P4) to the end point (P2, P6) and the state of charge SOC becomes the minimum state of charge SOC1 at the end point (P2, P6) in the excessive discharging sections Td1 and Td2. In the excessive discharging sections Td1 and Td2, the discharge amount with which the state of charge SOC reaches the minimum state of charge SOC1 is highly likely to be sufficiently ensured. This allows the state of charge SOC to reach the minimum state of charge SOC1 at the end point (P2, P6) with a high probability even if the upper limit values (fixed discharge current values Id1 and Id2) are set. Further, the torque control unit <NUM> controls the output of the M/G <NUM> by setting an upper limit value (fixed charge current value Ic1) in the excessive charging section Tc1. When the charge current value is maintained at the upper limit value, the state of charge SOC changes at a fixed change rate from the start point (P2) to the end point (P4) in the excessive charging section Tc1, and the state of charge SOC becomes the maximum state of charge SOC2 at the end point (P4). In the excessive charging section Tc1, the charge amount with which the state of charge SOC reaches the maximum state of charge SOC2 is highly likely to be sufficiently ensured. This allows the state of charge SOC to reach the maximum state of charge SOC2 at the end point (P4) with a high probability even if the upper limit value (fixed charge current value Ic1) is set.

As shown in the fourth section in <FIG>, such a configuration reduces the maximum temperature and the average temperature of the battery temperature TmpB while setting the state of charge SOC at each end point of the excessive discharging sections Td1 and Td2 and the excessive charging section Tc1 to be the same as the state of charge SOC in the normal control with a high probability. That is, the configuration ensures the charge/discharge amount of the battery <NUM> while curbing a rise in the battery temperature TmpB.

Another example of the temperature rise curbing control will now be described with reference to <FIG>. In <FIG>, the first section shows the changes in the state of charge SOC that occur when the normal control is performed, the second section shows the changes in the state of charge SOC that occur when the temperature rise curbing control is performed, and the third section shows the value of current flowing into the battery <NUM>.

As shown in the first section in <FIG>, an excessive discharging section Td3 in this example includes temporal charging sections Tc31 and Tc32. In the temporal charging sections Tc31 and Tc32, the state of charge SOC never reaches the maximum state of charge SOC2 during the fall in the state of charge SOC from the maximum state of charge SOC2 to the minimum state of charge SOC1. Further, an excessive charging section Tc4 includes a temporal discharging section Td4. In the temporal discharging section Td4, the state of charge SOC never reaches the minimum state of charge SOC1 during the rise in the state of charge SOC from the minimum state of charge SOC1 to the maximum state of charge SOC2.

As shown in the second and third sections in <FIG>, the torque control unit <NUM> controls the output of the M/G <NUM> with the normal control in the temporal charging sections Tc31 and Tc32 in the excessive discharging section Td3 and the temporal discharging section Td4 in the excessive charging section Tc4. Further, the torque control unit <NUM> controls the output of the M/G <NUM> by setting an upper limit value (fixed discharge current value Id3) in the excessive discharging section Td3. The upper limit value is set using at least a part of the section lengths in the charging sections Tc31 and Tc32 and using at least a part of a rise in the state of charge SOC. In a case where the discharge current value is maintained at the upper limit value, the state of charge SOC becomes the minimum state of charge SOC1 at the end point (position P16) of the excessive discharging section Td3. The torque control unit <NUM> controls the output of the M/G <NUM> by setting an upper limit value (fixed charge current value Ic4) in the excessive charging section Tc4. The upper limit value is set using at least a part of the section length in the discharging section Td4 and using at least a part of a fall in the state of charge SOC. In a case where the charge current value is maintained at the upper limit value, the state of charge SOC becomes the maximum state of charge SOC2 at the end point (position P19) of the excessive charging section Tc4.

Such a configuration reduces the maximum temperature and the average temperature of the battery temperature TmpB while setting the state of charge SOC at each end point of the excessive discharging section Td3 and the excessive charging section Tc4 to be the same as the state of charge SOC in the normal control with a high probability. That is, the configuration ensures the charge/discharge amount of the battery <NUM> while curbing a rise in the battery temperature TmpB.

The operation and advantages of the present embodiment will now be described.

The present embodiment may be modified as follows. The present embodiment and the following modifications can be combined as long as the combined modifications remain technically consistent with each other.

For example, when a minimum maintenance section includes a temporal charging section, a minimum maintenance section prior to the charging section and a minimum maintenance section subsequent to the charging section may be included in excessive discharging sections Td that differ from each other.

The excessive discharging section Td may include only a continuously falling section and a minimum maintenance section that follows the continuously falling section.

For example, when a maximum maintenance section includes a temporal discharging section, a maximum maintenance section prior to the discharging section and a maximum maintenance section subsequent to the charging section may be included in excessive charging sections Tc that differ from each other.

The excessive charging section Tc may include only a continuously rising section and a maximum maintenance section that follows the continuously rising section.

Claim 1:
A charging/discharging control device configured to control charging and discharging of a battery (<NUM>) installed in a hybrid vehicle (<NUM>) that includes a motor generator (<NUM>), the motor generator (<NUM>) being a power source, the charging/discharging control device comprising:
a route information acquisition unit (<NUM>) configured to acquire a planned travel route, a start point of the planned travel route being a current position;
a section identification unit (<NUM>) configured to estimate a change in a state of charge of the battery (<NUM>) using a change in potential energy on the planned travel route and identify an excessive discharging section and an excessive charging section on the planned travel route; and
a charging/discharging control unit (<NUM>) configured to control charging and discharging of the battery (<NUM>) by controlling an output of the motor generator (<NUM>), wherein
the excessive charging section includes a section where the state of charge continues to rise to a maximum state of charge and is then maintained at the maximum state of charge,
the excessive discharging section includes a section where the state of charge continues to fall to a minimum state of charge and is then maintained at the minimum state of charge,
characterized in that
the charging/discharging control unit (<NUM>) is configured
to limit a charge current value in the excessive charging section to a fixed first upper limit value, wherein the first upper limit value is set such that the state of charge reaches the maximum state of charge at an end point of the excessive charging section when the charge current value in the excessive charging section is maintained at the first upper limit value, and
to limit a discharge current value in the excessive discharging section to a fixed second upper limit value, wherein the second upper limit value is set such that the state of charge reaches the minimum state of charge at an end point of the excessive discharging section when the discharge current value in the excessive discharging section is maintained at the second upper limit value.