JP2001268715A - Method for controlling hybrid electric vehicle and warming-up thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heat the battery by controlling charging and discharging of a battery and to improve input and output characteristics of the battery with regard to the warm-up control of the battery when its temperature is low, because there is a problem in a hybrid electric vehicle that when it starts with the low-temperature battery, the input and output characteristics of the battery cannot sufficiently be utilized so that drive force required as a vehicle cannot be satisfied. SOLUTION: When the battery temperature detected is lower than a preset value in the hybrid electric vehicle, a drive force by an engine is decreased or increased by a given value and the drive force by a motor is increased or decreased by a given value. Each of the decreased or increased values is used as a command value to control discharging or charging of a battery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the power of an engine, the power of driving a motor using a battery as a power source,
The present invention relates to a hybrid electric vehicle that travels by using a hybrid electric vehicle and a warm-up control method thereof.

[0002]

2. Description of the Related Art In a start in winter or the like, since the battery temperature is low and the internal resistance of the battery is high, it may be difficult to start even with a general gasoline engine. In this regard,
The same applies to a hybrid electric vehicle that runs on the power of an engine and the power of driving a motor using a battery as a power source.

As a conventional technique for warming up a battery mounted on a vehicle, there is a technique described in, for example, Japanese Patent Application Laid-Open No. 2000-23307. This is because the temperature of the battery mounted in the hybrid vehicle is equal to or lower than a predetermined value or the internal resistance of the battery is equal to or higher than a predetermined value, the SOC (battery charge state) of the battery is equal to or higher than a predetermined value, and the engine coolant temperature is equal to or lower than a predetermined value. In this case, the temperature of the battery is increased by supplying electric power from the battery to the motor to start the engine, supplying electric power from the battery to the motor even after the start, and operating the motor in power.

[0004] Another known example is disclosed in Japanese Patent Application Laid-Open No. 9-275601.
There is an official gazette. This describes a case in which an air intake passage for taking in air around the engine is connected to the battery storage chamber in order to warm up the battery when the engine is cold.

[0005]

As described above, when a cold start is performed in a hybrid electric vehicle, the electric power that can be input to and output from the battery during the cold period is limited, and the engine using a motor, which is a feature of the hybrid vehicle, is used. There is a problem in that the amount of assisting driving force and the amount of energy regenerated during braking are limited, and fuel efficiency deteriorates. Therefore, when the outside air temperature is low, it is necessary to immediately warm the battery and improve the input / output of the battery.

If the electric power required for starting the engine cannot be obtained, the idling stop which is a feature of the hybrid electric vehicle cannot be performed, and the fuel efficiency will be deteriorated.

[0007] In the former method, when the temperature of the battery is lower than a predetermined value, power is supplied from the battery to the motor even after the engine is started, and the motor is operated by power to increase the temperature of the battery. However, when the SOC is determined to be in the battery discharge state larger than the predetermined value, the battery is necessarily discharged, and the current flowing through the battery is not taken into consideration, so that there is a disadvantage that the efficiency of warming up the battery is low. In the latter method of taking in air around the engine, a new passage must be provided, and the efficiency of warm-up is not good.

An object of the present invention is to provide a hybrid electric vehicle capable of satisfying a driving force required as a vehicle at the time of starting from a state where a battery temperature is low, and a warm-up control method thereof.

[0009] Another object of the present invention is to provide a battery control system in which even if it is determined that the battery discharge state has priority based on the SOC of the battery,
It is an object of the present invention to provide a hybrid electric vehicle and a warm-up control method for the hybrid electric vehicle, in which a large amount of current flows through the battery and a time for warming up the battery is increased by comparing the outputable power of the battery and the inputtable power of the battery.

[0010]

The present invention for solving the above problems is constituted by the following means. Means for running with the power of the engine, means for running with the power of the motor using the battery as a power source, and battery temperature detecting means for detecting the temperature of the battery; and a battery temperature detected by the battery temperature detecting means. When the temperature is lower than a predetermined temperature, an output command means of the engine which sets a command value to a value obtained by reducing a driving force running by the power of the engine by a predetermined value, and a driving force running by the power of the motor Motor output command means for setting a command value to a value obtained by increasing the value by a predetermined value, and discharge command means for giving a discharge command to the battery based on the engine output command value and the motor output command value. .

Means for running by the power of the engine; means for running by the power of the motor using the battery as a power source; means for charging the battery by the power of the engine; and battery temperature for detecting the temperature of the battery. Detection means, and when a battery temperature detected by the battery temperature detection means is lower than a predetermined temperature, a command value obtained by increasing a driving force for running by the power of the engine by a predetermined value. Output command means for the engine, motor output command means for setting the command value to a value obtained by reducing the driving force for running by the power of the motor by a predetermined value, the engine output command value and the motor output command value And a charge commanding means for giving a command to the battery charging means based on the above.

Further, the difference between the previous value of the engine output command value and the previous value of the motor output command value and the value calculated this time is limited to a predetermined value or less, or the temperature detected by the battery temperature detecting means is determined in advance. When the available output power of the battery is lower than a predetermined value and lower than a predetermined value, a discharge command is not given to the battery.

Means for running by the power of the engine; means for running by the power of the motor using the battery as a power source; means for charging the battery by the power of the engine; and battery temperature for detecting the temperature of the battery. Detection means, and when a battery temperature detected by the battery temperature detection means is lower than a predetermined temperature, a command value obtained by reducing a driving force for running by the power of the engine by a predetermined value. Output command means for the engine, motor output command means for setting a value obtained by increasing a driving force running by the power of the motor by a predetermined value as a command value, the engine output command value and the motor output command value Control by discharge command means for giving a discharge command to the battery based on the battery temperature detecting means An output command means of the engine to a value increased by a predetermined value the driving force more detected battery temperature travels by the power of the engine is lower than the predetermined temperature and the command value,
A motor output commanding unit that sets a command value to a value obtained by reducing a driving force running by the power of the motor by a predetermined value; and a command to the battery charging unit based on the engine output command value and the motor output command value. And the control by the applied charge command means is alternately repeated.

[0014] Further, means for running with the power of an engine, means for running with the power of a motor using a battery as a power source, means for charging the battery with the power of the engine, and battery temperature for detecting the temperature of the battery Detecting means, wherein when the battery temperature detected by the battery temperature detecting means is lower than a predetermined value and the outputable power of the battery is lower than a predetermined value, and when the SOC is lower than a predetermined value, charging control is performed; When the SOC is larger than a predetermined value, the input / output power of the battery is compared. When the input power is large, charging control is performed. When the output power is large, the required driving force is compared with the inputtable power. When the electric power is large, charge control is performed, and when the required driving force is large, discharge control is performed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a hybrid electric vehicle according to the present invention will be described below in detail with reference to the drawings. FIG.
1 shows an embodiment of a device configuration and a control block configuration of a hybrid electric vehicle. The power train of this hybrid electric vehicle includes a motor 11, an engine 12,
Clutch 13, motor 14, CVT (continuously variable transmission) 1
5 and drive wheels 16. The motor 11 and the engine 12 are drivingly connected, and the engine 12 and the motor 14 are drivingly connected via a clutch 13. The clutch 13 can separate the power between the engine 12 and the motor 14 depending on the operation of the driver and the state of the vehicle. The motor 14 and the drive wheels 16 are CVT (Continuously Variable Transmission) 1
The CVT 15 is capable of transmitting an optimal driving force to the axle 16 by changing the gear ratio. Further, the battery 17 is connected to the motor 11 and the motor 14 through an inverter 18.

The hybrid electric vehicle runs with the power of both the engine 12 and the motor 14 when the clutch 13 is engaged, and runs with the power of the motor 14 alone, that is, the battery as the power source when the clutch 13 is released. Engine 12
And / or the driving force of the motor 14 is transmitted to the driving wheels 16 via the CVT 15.

The motors 11 and 14 are AC machines such as a three-phase synchronous motor or a three-phase induction motor. The motor 11 is mainly used for starting and generating the engine, and the motor 14 is mainly used for propulsion and braking of the vehicle. Motor 1
1, 14 are not limited to AC machines, but DC motors can also be used. When the clutch 13 is engaged, the motor 11
Can also be used for propulsion and braking of the vehicle.
Can be used for engine start and power generation.

The clutch 13 is a powder clutch in this example, and the transmission torque can be adjusted because the transmission torque is almost proportional to the exciting current. The CVT 15 is a continuously variable transmission such as a belt type or a toroidal type, and is capable of continuously adjusting the speed ratio.

The motors 11 and 14 are each driven by an inverter 18. The motors 11, 14
In the case where a DC motor is used, a DC / DC converter is used instead of the inverter 18. The inverter 18 is connected to the battery 17, converts the DC power of the battery 17 into AC power and supplies the AC power to the motors 11 and 14, and converts the AC power generated by the motors 11 and 14 into DC power to convert the battery 17 into DC power. Charge. Further, as the battery 17, a lithium ion battery, a nickel hydride battery, a lead battery, or the like is used.

The integrated control device 21 includes a microcomputer and its peripheral parts, various actuators, and the like.
Rotation speed and output torque of engine 12, transmission torque of clutch 13, output torque of motors 11 and 14, CVT
15 and the charge / discharge of the battery 17 are controlled.

The integrated control device 21 is connected to devices as shown in FIG. One of the P, N, R, and D switches of the select lever SW31 is turned on in accordance with a set position of a select lever (not shown) for switching between parking P, neutral N, reverse R, and drive D.

The accelerator sensor 32 detects the amount of depression of the accelerator pedal (hereinafter referred to as accelerator opening), and the brake switch 33 detects the state of depression of the brake pedal (at this time, switch on). The vehicle speed sensor 34 detects the running speed Vs of the vehicle, and the battery temperature sensor 35 detects the temperature Tb of the battery 17. Further, the battery remaining amount detecting device 36 detects the state of charge of the battery 17. Further, the engine rotation sensor 37
Detects the rotation speed Ne of the engine 12.

The fuel injection device 41 injects fuel to the engine 12, and the ignition device 42 ignites the engine 12. The auxiliary battery 43 supplies low-voltage power to on-vehicle devices such as the integrated control device 21.

FIG. 3 is a block diagram for controlling charging of the engine 12, the motors 11, 14 and the battery by the integrated control unit 21, and shows a command value distribution means for the engine and the motor. In block C1 of FIG. 3, the accelerator opening detected by the accelerator sensor 32 and the vehicle speed V detected by the vehicle speed sensor 34 are set.
Based on s, a target drive torque τs on the drive shaft is determined.

In a block C2 of FIG. 3, a target drive torque τde converted around the engine axis is obtained based on the target drive torque τs and the actual speed ratio of the CVT 15.

In block C3 of FIG. 3, the engine speed Ne is input to a best fuel consumption line torque map in which points having the lowest fuel consumption rate with respect to torque are connected for each rotation speed, and the best fuel consumption torque τa is obtained. . Block C4 in FIG.
Then, a process of limiting the best fuel consumption torque τa plus the battery warm air correction value by the upper limit / lower limit torque of the engine is performed to obtain the engine output possible torque τle.

In block C5 in FIG. 3, a provisional engine torque value τg obtained by subtracting a required power generation torque obtained from the power used by each annotation and the state of the battery from the target drive torque τde around the engine axis, and an engine output available torque τ
The engine torque command value τe is determined by comparing the value with le and selecting the smaller value. In the case of the normal control, the best fuel consumption torque τa is compared with the provisional engine torque value τg, and the smaller one is selected, and the smaller one is selected.
Find e.

The motor torque command value τm is obtained by subtracting the engine torque command value τe from the target drive torque τde. When the motor torque command value τm is positive, the motor 14 is mainly driven, and when the motor torque command value τm is negative, the motor 1 is mainly driven.
1 to charge the battery 17.

Here, the target driving torque τde around the engine axis obtained from the block C2 in FIG.
If it is larger than the engine output possible torque τle obtained in step 4, a positive value is output as the motor torque command value τm. However, in this case, in the normal control, a shift command is simultaneously issued to the CVT 15, and the engine speed Ne is increased so that the motor torque command value τm becomes zero.

Therefore, in this case, the motor torque command value τ
Since m approaches 0 and the battery is no longer discharged,
The temperature of the battery does not rise and the input / output of the battery does not improve. Thus, the battery is charged / discharged by changing the battery warm air correction value to positive or negative, and the input / output of the battery is improved. Further, the target driving torque τde is multiplied by the vehicle speed to perform unit conversion to calculate a target driving power Pd.

Hereinafter, the means for calculating the battery warm air correction value will be described in detail with reference to a flowchart.

The integrated control device 21 is shown in FIG. 4, FIG. 5, FIG.
7, 8, and 9 are sequentially performed to obtain a battery warm-up correction value, and to calculate a target drive torque and a desired charge power obtained from the power used by auxiliary devices such as control devices and the battery state. The engine output command value, the motor output command value, and the charging power command value are distributed.

In FIG. 4, the integrated control device 21 determines that the battery temperature Tb is lower than the predetermined value T (S11), that is, Tb <
If T and the possible battery output power Pb is less than the predetermined value P (S12), that is, if Pb <P and the vehicle is running (S13, Yes), the warm-up control permission flag for the battery is turned on (S14). ). T is a predetermined temperature for determining whether or not to perform the battery warm-up control, and P is a predetermined power value as the outputable power of the battery. When the battery temperature is equal to or higher than T (S11, No) or the battery output available power is equal to or higher than P (S12, No), or when the vehicle is not running (S13, No), the battery warm-up control permission flag is set. Is turned off (S15). That is, since the battery temperature is relatively high, warm-up control is not performed.

Next, the case where the warm-up control of the battery is performed will be described. When the battery warm-up control permission flag is ON (condition of S14) and the SOC is equal to or more than the predetermined value SOC1 (S22, YES), the integrated control device 21 turns off the battery charge flag 1 in S21 of FIG. (S23), the warm-up control permission flag of the battery is turned on (S23).
21, YES) and if the SOC is less than the predetermined value SOC2 (S24, YES), the battery charge flag 1 is set to O.
N is performed (S25).

The integrated control device 21 turns on the battery charge flag when the battery warm-up control permission flag is ON (S31, Yes) and the battery charge flag 1 is ON (S32, No) in FIG. (S36).

When the battery warm-up control permission flag is set to O
If N (S31, Yes), the battery charge flag 1 is OFF (S32, Yes), and the available output power of the battery is equal to or less than the available battery input power (S33, No), the battery charge flag is turned ON (S33, No). S36).

The battery warm-up control permission flag is set to O
N (S31, Yes), the battery charge flag 1 is OFF (S32, Yes), and the battery output available power is larger than the battery input available power (S33, Yes)
If s) and the target driving force (power) is less than the battery inputtable power (S34, No), the battery charge flag is turned ON (S36). Further, when the battery warm-up control permission flag is ON (S31, Yes), the battery charge flag 1 is OFF (S32, Yes), and the battery output possible power is larger than the battery input possible power (S33, Yes). If the target driving force (power) is larger than the battery inputtable power (S34, Yes), the battery charge flag is turned off (S35).

Next, in FIG. 7, the integrated control device 21 turns on the battery warm-up control permission flag (S41, Yes).
And if the battery charge flag is OFF (S42,
Yes) It is determined that the battery is in the discharged state, and the available battery output power is substituted into the battery warm-up correction value α (S43),
(Target driving force (power) + power used by accessories-α)
Is set as an engine output command value (S44), and (α-power used by auxiliary equipment) is set as a discharge command value and a motor output command value. The battery warm-up control permission flag is ON (S41, Y
es) and if the battery charge flag is ON, it is determined that the battery is in the charged state (S42, No), and in the chargeable power calculation step (S45), the battery inputtable power is substituted for α (S45), and the battery is charged. (Target driving force (power) + power used by auxiliary equipment + α) as an engine output command value, and (power used by auxiliary equipment + α) as a charge command value and a motor power generation command value ( S46). When the battery warm-up control permission flag is OFF (S4
1, No), normal control is performed.

In FIG. 8, the integrated controller 21 determines that the battery warm-up control permission flag is ON (S51, Yes) and the engine output command value is larger than the past value of the engine output command value (S52, Yes). In addition, (the engine output command value-the past value of the engine output command value) is equal to the predetermined value Te.
If it is larger than d1 (S53, Yes), the engine output command value is set to (the past value of the engine output command value + Ted1) (S54), and finally, the past value of the engine output command value is updated to the engine output command value (S57). .

When the battery warm-up control permission flag is set to O
N (S51, Yes) and when the engine output command value (engine torque command value) is equal to or less than the past value of the engine output command value (S52, No), and (Engine output command value-past of engine output command value) Value) is a predetermined value (-Ted
2) If smaller (S55, Yes), the engine output command value is set to (past value of engine output command value-Ted2) (S56), and finally, the past value of engine output command value is
The engine output command value is updated (S57). They are,
There is an effect that a large change in the command value can be suppressed.

In FIG. 9, the integrated control device 21 determines that the battery warm-up control permission flag is ON (S61, Yes) and that the charge command value (motor torque command value) is larger than the past charge command value (S62). , Yes) and (the charge command value−the past value of the charge command value) is larger than the predetermined value Tcd1 (S63, Yes), the charge command value is set to (the past value of the charge command value + Tcd1) (S64), and finally , The past value of the charge command value is updated to the charge command value (S67).

When the battery warm-up control permission flag is ON (S
61, Yes) and the charge command value is equal to or less than the past value of the charge command value (S62, No), and (the charge command value−the past value of the charge command value) is smaller than the predetermined value (−Tcd2) (S6).
(5, Yes), the charge command value is set to (past value of charge command value−Tcd2) (S66), and finally, the past value of the charge command value is updated to the charge command value (S67). This also suppresses a large change in the charge command value.

Next, FIGS. 10 and 11 show conceptual diagrams of energy flows in the hybrid electric vehicle. FIG. 10 shows a case where the vehicle is driven and driven by using a battery as a power source, and FIG. 11 shows a case where the vehicle is driven and driven by an engine. The case where the motor 11 generates power and is charged via the inverter 18 is shown.

When the hybrid electric vehicle is in the battery discharge state, the electric power stored in the battery 17 is supplied to the motor 14 via the inverter 18 as shown in FIG. Driving the driving wheels with power causes the vehicle to run, thereby consuming power from the battery, thereby warming up the battery.

When the battery is in the charged state, the driving force of the engine 12 is applied to the motor 11 as shown in FIG. 11 and stored in the battery 17 via the inverter 18 to warm up the battery. Driving wheels are driven by 12 driving forces to travel.

As described above, according to the present invention, charge / discharge control with a high warming effect can be always performed by considering the target driving force and the input / output power of the battery.

FIG. 12 shows how the driving force of the hybrid electric vehicle changes during battery warm-up control.
become that way. The engine torque command value τe, the target drive torque τ, where the vertical axis of the graph is the drive torque and the horizontal axis is the time
s, a motor torque command value τm, which is the total drive torque of the motor 11 and the motor 14. In the case of the battery discharge state between T1 and T3, the energy amount of the motor used for traveling is in a region surrounded by (T2, Tr1), (T3, 0), and (T1, 0), and between T3 and T5. (T3, 0) and (T5,
0) and (T4, Tr0). The temperature of the battery rises according to the size of these areas.

By this traveling operation, the input / output characteristics of the battery during cold operation can be improved.

[0049]

According to the present invention, the output command value of the engine is changed when the battery is charged or discharged in a cold state, so that the input / output characteristics of the battery can be changed without affecting the running of the vehicle. Can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control device and a device configuration of a hybrid electric vehicle according to the present invention.

FIG. 2 is a block diagram of devices connected to the vehicle control device of the present invention.

FIG. 3 is a control block diagram of the present invention.

FIG. 4 is a (first) flowchart for explaining the present invention.

FIG. 5 is a (second) flowchart for explaining the present invention.

FIG. 6 is a (third) flowchart for explaining the present invention.

FIG. 7 is a (fourth) flowchart for explaining the present invention.

FIG. 8 is a (fifth) flowchart for explaining the present invention.

FIG. 9 is a (sixth) flowchart for explaining the present invention.

FIG. 10 is a diagram showing an energy flow (arrow) in the hybrid electric vehicle.

FIG. 11 is a diagram showing an energy flow (arrow) in the hybrid electric vehicle.

FIG. 12 is a diagram for explaining driving force distribution according to the present invention.

[Explanation of symbols]

11 ... motor, 12 ... engine, 13 ... clutch, 14
... Motor, 15 ... CVT, 16 ... Drive wheels, 17 ... Battery, 18 ... Inverter, 21 ... Integrated control device, 31 ... Select lever SW, 32 ... Accelerator sensor, 33 ... Brake SW, 34 ... Vehicle speed sensor, 35 ... Battery Temperature sensor, 36: battery remaining amount detecting device, 37: engine rotation sensor, 41: fuel injection device, 42: ignition device, 43 ...
Auxiliary battery, 50 ... command value distribution means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // B60K 6/02 B60K 9/00 E (72) Inventor Tetsuo Matsumura 2520 Takahiro Daiba, Hitachinaka City, Ibaraki Prefecture Hitachi, Ltd. Automotive Equipment Group (72) Kinya Fujimoto, Inventor Kinya Fujinaka, Ibaraki Pref. Nissan Motor Co., Ltd. (72) Inventor Jun Ichiraku 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Nissan Motor Co., Ltd. (72) Inventor Jun Shoji 2 Takaracho, Kanagawa-ku, Yokohama City, Kanagawa Nissan Motor Co., Ltd. ) Inventor Kazuma Okura 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. F-term (reference) 3D039 AB27 3G093 AA06 AA07 AA16 DA01 DA06 DB00 DB05 DB09 DB11 DB19 DB20 EA01 EB00 FA11 FB00 FB05 5H115 PI16 PI23 PI24 PI29 PO02 PO06 PO09 PU02 PU09 PU10 PU22 PU24 PU25 PU29 PV02 PV09 QE20 RE13 RE05 REN SE04 SE05 SE06 SE08 SE09 TB01 TE02 TI02 TI10 TO21 TO23 TR19 TU11 TZ01

Claims (6)

[Claims] A motor driven by a motor as a power source; and a battery temperature detector for detecting a temperature of the battery. The battery temperature detector detects the temperature of the battery. An engine output commanding means for setting a command value to a value obtained by reducing a driving force running by the power of the engine by a predetermined value when the detected battery temperature is lower than a predetermined temperature; Motor output commanding means for setting a value obtained by increasing the driving force for traveling by a predetermined value as a command value, and discharging commanding means for giving a discharging command to the battery based on the engine output command value and the motor output command value. A hybrid electric vehicle comprising: 2. A means for running with the power of an engine, a means for running with the power of a motor using a battery as a power source, a means for charging the battery with the power of the engine, and a battery temperature for detecting the temperature of the battery. Detection means, and when a battery temperature detected by the battery temperature detection means is lower than a predetermined temperature, a command value obtained by increasing a driving force for running by the power of the engine by a predetermined value. Output command means for the engine, motor output command means for setting the command value to a value obtained by reducing the driving force for running by the power of the motor by a predetermined value, the engine output command value and the motor output command value A charge command means for giving a command to the battery charge means based on the Automobile. 3. The hybrid electric vehicle according to claim 1, wherein a difference between a previous value of the engine output command value and a previous value of the motor output command value and a value calculated this time is limited to a predetermined value or less. 4. A discharge command is issued to the battery when the temperature detected by the battery temperature detecting means is lower than a predetermined value and the outputable power of the battery is lower than the predetermined value. A hybrid electric vehicle characterized by the absence. 5. A means for running with the power of an engine, a means for running with the power of a motor using a battery as a power source, a means for charging the battery with the power of the engine, and a battery temperature for detecting the temperature of the battery. Detection means, and when a battery temperature detected by the battery temperature detection means is lower than a predetermined temperature, a command value obtained by reducing a driving force for running by the power of the engine by a predetermined value. Output command means for the engine, motor output command means for setting a value obtained by increasing a driving force running by the power of the motor by a predetermined value as a command value, the engine output command value and the motor output command value Control by a discharge command means for giving a discharge command to the battery based on An engine output command means for setting a value obtained by increasing a driving force running by the power of the engine by a predetermined value when the output battery temperature is lower than a predetermined temperature as a command value, and a power of the motor; Motor output command means for setting a command value to a value obtained by reducing the driving force for traveling by a predetermined value, and charge command means for giving a command to the battery charging means based on the engine output command value and the motor output command value. A hybrid electric vehicle characterized by alternately repeating the control by: 6. A means for running with the power of an engine, a means for running with the power of a motor using a battery as a power source, a means for charging the battery with the power of the engine, and a battery temperature for detecting the temperature of the battery. When the battery temperature detected by the battery temperature detecting means is lower than a predetermined value and the outputable power of the battery is lower than the predetermined value, and when the SOC (battery charge state) is lower than the predetermined value. Controls the charging, compares the input / output power of the battery when the SOC is larger than a predetermined value, controls the charging when the input power is large, and compares the required driving force and the inputtable power when the output power is large. Comparing the chargeable power when the inputtable power is large, and performing the discharge control when the required driving force is large. Head of electric car warm-up control method.