Battery temperature control system in vehicle

Abstract

To provide a battery temperature control system in a vehicle which can sufficiently warm up a battery to elevate a battery temperature.SOLUTION: A battery temperature control system 2 mounted on a vehicle comprises: an electric motor 6 with three-phase coils 10, 11, 12; and a storage battery 5 which supplies the electric motor 6 with electric power. The battery temperature control system includes an inverter 15 and a storage battery temperature control part 30 which can respectively electrify the coils 10, 11, 12 of the electric motor 6 through electric power supplied from the storage battery 5. The storage battery temperature control part 30 executes storage battery temperature control which electrifies only one phase of the three-phase coils 10, 11, 12 from the storage battery 5 and switches the electrified coil among the coils 10, 11, 12 per prescribed period so that the storage battery 5 is heated by self-heating of the storage battery 5.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a battery temperature control technology for warming a storage battery mounted on a vehicle. [Background technology]

[0002] Electric vehicles and hybrid vehicles are equipped with a relatively large-capacity storage battery as a power source for the electric motor that drives the vehicle. To ensure sufficient battery output in cold climates, some vehicles have been equipped with a temperature control device that warms the storage battery. For example, in Patent Document 1, when the temperature of a storage battery drops, an air conditioner is operated, a capacitor is charged, etc., and the current flowing through the storage battery causes the storage battery to generate heat, thereby raising the temperature of the storage battery. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-48485 Summary of the Invention [Problem to be solved by the invention]

[0004] In addition, a technology has been devised to supply power from the storage battery to an electric motor to warm the battery. For example, by passing current through only one of the three phase coils of the electric motor, the drive of the electric motor is suppressed, and the current flowing through the storage battery causes it to generate heat, thereby raising the temperature of the storage battery. However, if current is applied to only one phase of the coil of the electric motor as described above, there is a risk that the temperature of that coil will rise excessively in a short period of time, so the current flowing through the coil must be suppressed, making it difficult to efficiently warm up the storage battery.

[0005] The present invention has been made in consideration of these problems, and its purpose is to provide a battery temperature control system for a vehicle that is capable of sufficiently warming the battery temperature in a battery temperature control device that supplies power from a storage battery to energize the coil of an electric motor, causing the storage battery to generate heat by the current flowing through it. [Means for solving the problem]

[0006] In order to achieve the above object, the vehicle battery temperature control system of the present invention is a battery temperature control system installed in a vehicle having an electric motor with a three-phase coil and a storage battery that supplies power to the electric motor, and has a control unit that can individually energize the coils of the electric motor using power supplied from the storage battery, and the control unit performs battery temperature control by energizing only one phase of the three-phase coil from the storage battery and switching the coil to be energized at predetermined intervals, thereby heating the storage battery through the self-heating of the storage battery. [Effects of the Invention]

[0007] According to the vehicle battery temperature control system of the present invention, by passing current from the storage battery to only one phase of the three-phase coil of the electric motor, the operation of the electric motor can be suppressed while the temperature of the storage battery is raised by self-heating caused by the current flowing through the storage battery. Furthermore, by switching the coil to which current is applied, it is possible to ensure a long period of time for current to be supplied from the storage battery to the motor while preventing the coil temperature from rising above the allowable limit, thereby making it possible to sufficiently warm up the storage battery. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram of a battery temperature control system for a vehicle according to an embodiment of the present invention; [Figure 2] 4 is a time chart showing changes in the current and temperature of each coil of the motor due to battery temperature adjustment control in the battery temperature adjustment system of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a battery temperature control system according to an embodiment of the present invention will be described. FIG. 1 is a schematic diagram of a battery temperature regulation system 2 of a vehicle 1 according to this embodiment. The battery temperature control system 2 of this embodiment is used in a vehicle 1 equipped with a storage battery 5 and an electric motor 6 (electric motor) that is powered by electricity supplied from the storage battery 5 and drives the vehicle, such as an electric vehicle or a plug-in hybrid vehicle (PHEV) that can be externally charged or externally powered.

[0010] The electric motor 6 is a three-phase motor having three coils: a U-phase coil 10, a V-phase coil 11, and a W-phase coil 12. The electric motor 6 is driven by power supplied from the storage battery 5 via an inverter 15 (controller). The inverter 15 is controlled by a control unit 20 (controller) that performs overall control of the vehicle 1, and supplies (energizes) current to the coils 10, 11, and 12 of each phase using power supplied from the storage battery 5, thereby driving and rotating the electric motor 6.

[0011] Coil temperature sensors 21, 22, 23 (temperature detectors) are provided on the coils 10, 11, 12 of the electric motor 6, respectively. The coil temperature sensors 21, 22, 23 enable detection of the temperature of each of the coils 10, 11, 12. The inverter 15 is provided with a motor protection circuit 25 (coil protection control unit). When the coil temperature of at least one phase among the temperatures of the coils 10, 11, and 12 input from the coil temperature sensors 21, 22, and 23 reaches or exceeds an allowable upper limit temperature Tb, the motor protection circuit 25 stops the supply of current to all the coils 10, 11, and 12 or reduces the supply current.

[0012] The storage battery 5 is also provided with a storage battery temperature sensor 26 that detects the temperature of the storage battery 5 . The vehicle 1 is provided with a charger 31 that charges the storage battery 5 with power supplied from an external source. The control unit 20 includes an input / output device, a storage device (ROM, RAM, non-volatile RAM, etc.), a central processing unit (CPU), and the like.

[0013] The control unit 20 is equipped with a battery temperature adjustment control unit 30 (control unit). When the battery 5 is being charged by the charger 31, the battery temperature adjustment control unit 30 inputs the temperature of the battery 5 from the battery temperature sensor 26, and performs battery temperature increase control to increase the temperature of the battery 5 when the temperature of the battery 5 is low and below a predetermined temperature Ta. The predetermined temperature Ta may be set, for example, near the lower limit of the usable temperature of the battery 5 or near the lower limit of the temperature range j at which the battery 5 can efficiently output power.

[0014] FIG. 2 is a time chart showing an example of transition of each coil current and coil temperature in the storage battery temperature regulation control. The battery temperature control unit 30 controls the battery temperature rise when the temperature of the battery 5 is low, i.e., below a predetermined temperature Ta, by controlling the power supplied from the battery 5 to energize only one of the three-phase coils 10, 11, and 12 of the electric motor 6.

[0015] As shown in Fig. 2, an appropriately set current is applied to each coil of each phase in the order of, for example, U-phase coil 10, V-phase coil 11, and W-phase coil 12. This causes the temperature of only the coils to which current is applied to rise. The currents supplied to the coils 10, 11, and 12 are the same. Then, for example, when the temperature of each of the coils 10, 11, 12 reaches a switching temperature Tc that is slightly lower than the allowable upper limit temperature Tb, the coil to which current is applied is switched.

[0016] As described above, by starting the battery temperature control and energizing the coils 10, 11, and 12, the temperature of the coils 10, 11, and 12 increases due to the resistance of the coils 10, 11, and 12. Note that the temperature of the coils that are not energized hardly increases. By switching the coil to be energized as described above, the temperature of the energized coil can be prevented from reaching the allowable upper limit temperature Tb. Also, by subsequently energizing the other coils, the coil temperature of the coils 10, 11, and 12 of each phase can be prevented from reaching the allowable upper limit temperature Tb. The total energization time, i.e., the time for output from the storage battery 5 to the electric motor 6, can be secured to be three times longer than when only one phase coil is supplied. Note that if the temperature of one of the coils of the electric motor 6 reaches the allowable upper limit temperature Tb and then energization is switched to another coil, the temperature of the coil that had been energized up until then will decrease, so that after energizing the three phase coils in order, it is possible to energize the three phase coils in order again, repeating this process.

[0017] If only one of the coils 10, 11, and 12 of the three-phase electric motor 6 is energized, the electric motor 6 will not operate. When power is supplied to the electric motor 6 from the storage battery 5, the storage battery 5 generates heat due to the internal resistance generated when current flows through the storage battery 5. This allows the temperature of the storage battery 5 to be raised without operating the electric motor 6. In particular, by switching the coils 10, 11, and 12 to which current is supplied, it is possible to prevent the temperatures of the coils 10, 11, and 12 from rising excessively, and also to ensure a long period of time for which power is output from the storage battery 5, thereby promoting a rise in the temperature of the storage battery 5.

[0018] In the above embodiment, when the temperature of each of the coils 10, 11, 12 reaches a switching temperature Tc that is slightly lower than the allowable upper limit temperature Tb, the coils 10, 11, 12 to which current is supplied are switched, thereby preventing the temperature of each of the coils 10, 11, 12 from exceeding the allowable upper limit temperature Tb. Note that the inverter 15 is provided with a motor protection circuit 25 that stops the supply of power to all of the coils 10, 11, 12 when the temperature of at least one of the coils 10, 11, 12 exceeds the allowable upper limit temperature Tb. However, even if the inverter 15 has such a function, the coil temperature will not reach the allowable upper limit temperature Tb when the battery temperature control is executed, and the battery temperature control can be continued to raise the temperature of the battery 5.

[0019] The vehicle 1 of this embodiment is equipped with a charger 31 that charges the storage battery 5 with power supplied from an external source. When the storage battery 5 is being charged by the charger 31, battery temperature control is performed based on the temperature of the storage battery 5. This allows the storage battery 5 to be heated while continuing charging without driving the electric motor 6 used for driving the vehicle. By performing battery temperature control during charging while power is being supplied from an external source, the temperature of the storage battery 5 can be raised without reducing the state of charge of the storage battery 5. Even when charging is performed in a cold state, for example, the temperature of the storage battery 5 has risen when charging is completed, allowing the storage battery 5 to fully demonstrate its output performance immediately after charging is completed. This ensures output from the electric motor 6 immediately after charging is completed, improving the driving performance of the vehicle 1.

[0020] Furthermore, in this embodiment, the battery temperature control is performed using the electric motor 6 for driving the vehicle, which can accept a relatively large current and in which the temperature of the coils 10, 11, and 12 is unlikely to rise. Therefore, the current supplied to the coils 10, 11, and 12 during the battery temperature control can be set large and supplied for a long period of time, and the temperature of the battery 5 can be raised sufficiently. The present invention is not limited to the above-described embodiment, and can be modified within the scope of the invention.

[0021] For example, in the above embodiment, when the temperature of coils 10, 11, and 12 reaches the switching temperature Tc, the current is switched to other coils, but it may also be switched every predetermined time, or when the integrated value of the time that current is supplied to the coils and the supplied current exceeds an appropriately set predetermined value. In the above embodiment, the battery temperature rise control is performed when the battery 5 is being charged, but the temperature of the battery 5 may be constantly detected to perform the battery temperature rise control, or the temperature of the battery 5 may be detected, for example, several tens of minutes before a preset time when the vehicle is to start being used to perform the battery temperature rise control. Also, an operation switch for executing the battery temperature adjustment control based on the temperature of the battery 5 may be provided on the vehicle 1, its smart key, or the like.

[0022] In addition, in the above embodiment, the storage battery 5 is heated by energizing the electric motor 6 for driving the vehicle 1, but other electric motors equipped with a three-phase coil mounted on the vehicle, such as an electric motor other than that for driving the vehicle, or an alternator, may also be used. [Explanation of symbols]

[0023] 1 vehicle 2. Battery temperature control system 5. Storage battery 6 Electric motor 10 U-phase coil (coil) 11 V-phase coil (coil) 12 W-phase coil (coil) 15 Inverter (control unit) 21, 22, 23 Coil temperature sensor (temperature detector) 25 Motor protection circuit (coil protection control unit) 30 Battery temperature control unit (control unit) 31 Charger

Claims

1. A battery temperature control system provided in a vehicle having an electric motor with a three-phase coil and a storage battery that supplies power to the electric motor, a control unit capable of individually energizing the coils of the electric motor using power supplied from the storage battery; The control unit energizes only one of the three-phase coils from the storage battery, switches the coil to be energized at predetermined intervals, and performs storage battery temperature control to heat the storage battery by self-heating of the storage battery. A vehicle battery temperature control system.

2. a temperature detector for detecting the temperature of the coil is provided for each of the coils; The control unit switches the coil to which current is supplied based on the temperature of the coil to which current is supplied in the storage battery temperature regulation control.

2. The vehicle battery temperature control system according to claim 1.

3. The control unit switches the coil to be energized based on a supply current and a current supply time to the coil of one phase in the storage battery temperature regulation control.

2. The vehicle battery temperature control system according to claim 1.

4. the vehicle includes a charger that charges the storage battery with power supplied from an external source; The control unit executes the temperature regulation control of the storage battery when the storage battery is charged from an external source.

2. The vehicle battery temperature control system according to claim 1.

5. a temperature detector for detecting the temperature of the coil is provided for each of the coils; The vehicle is equipped with a coil protection control unit that stops power supply to the coil when the temperature of at least one of the three-phase coils exceeds a predetermined allowable upper limit temperature.

2. The vehicle battery temperature control system according to claim 1.

6. The electric motor is an electric motor for driving the vehicle.

2. The vehicle battery temperature control system according to claim 1.

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