Electric motorcar

Abstract

To stabilize circuit travel by inhibiting implementation of protection control due to a temperature rise of a battery or a power unit in an electric motorcar.SOLUTION: An electric motorcar includes: a power unit that has a motor for driving wheels; a battery that supplies electric power to the motor; a cooling apparatus that cools at least one of the battery and the power unit; a cooling controller that controls an operation of the cooling apparatus according to a set target temperature; and a navigation system in which a destination of the electric motorcar is set.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology disclosed in this specification relates to an electric vehicle. The term "electric vehicle" broadly refers to a vehicle whose wheels are driven by a motor, and includes, for example, battery electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, and fuel cell electric vehicles. [Background technology]

[0002] Patent Document 1 describes a speed limiting device mounted on a vehicle. This speed limiting device grasps the current position of the vehicle using current position information acquired by a navigation device. Then, the speed limiting device judges whether the vehicle has entered the area of ​​a circuit using the current position information of the vehicle and area range information for entry judgment preset in the navigation device. The speed limiting device also judges whether the vehicle has exited the area of ​​a circuit using the current position information of the vehicle and area range information for exit preset in the navigation device. Depending on the result of the judgment on entry and exit to the circuit, the speed limiting device controls the upper limit speed of the vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-167827 A Summary of the Invention [Problem to be solved by the invention]

[0004] When an electric vehicle travels on a circuit, the output from the power unit is greater than normal when compared to normal travel on public roads, and the amount of heat generated by the battery or power unit increases. In addition, if the electric vehicle is driven at high load or quick-charged when traveling to the circuit, the battery and / or power unit may be hot when the electric vehicle arrives at the circuit. If the vehicle starts traveling on the circuit in the above state, the temperature of the battery or power unit may rise further, and protective control to prevent overheating may be activated shortly after the vehicle starts traveling. If such protective control is activated, the driving force of the motor may be limited, and there is a risk that the vehicle may not be able to travel on the circuit as intended by the occupants.

[0005] In view of the above, the present specification provides a technology that prevents or suppresses overheating of the battery and / or power unit, enabling circuit driving in line with the intentions of the occupants. [Means for solving the problem]

[0006] The technology disclosed in this specification is embodied in an electric vehicle that drives wheels by a motor. The electric vehicle includes a power unit having a motor that drives the wheels, a battery that supplies power to the motor, a cooling device that cools at least one of the battery or the power unit, a cooling control device that controls the operation of the cooling device according to a set target temperature, and a navigation system in which the destination of the electric vehicle is set.

[0007] The navigation system has a function of determining whether the destination is a circuit or not, and when the navigation system determines that the destination is a circuit, the cooling control device executes a specific control mode that sets the target temperature to a value lower than normal.

[0008] According to the above configuration, when the destination of the electric vehicle is set to a circuit in the navigation system, the cooling control device sets the cooling target temperature of the battery and / or power unit to a value lower than normal. With the above setting, the amount of operation by the cooling device increases while the electric vehicle is on its way to the circuit, suppressing a rise in temperature of the battery and / or power unit. As a result, the temperature of the battery and / or power unit upon arrival at the circuit is kept lower than normal, and overheating of the battery and / or power unit can be avoided or suppressed even if the electric vehicle is driven on the circuit immediately after arriving at the circuit.

[0009] In one embodiment of the present technology, the electric vehicle may further include a driving control device capable of executing cruise control that controls the operation of the motor in accordance with a set target speed. In this case, when executing the cruise control while the cooling control device is executing the specific control mode, the driving control device may set the target speed to a value lower than the normal speed in accordance with a cooling state of the battery or the power unit.

[0010] According to the above configuration, when cruise control is used while the electric vehicle is on its way to a circuit, overheating of the battery and / or the power unit can be effectively avoided or suppressed. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a block diagram showing the configuration of an electric vehicle 10. [Diagram 2] 5 is a flowchart showing an example of a process executed by the ECU 22 to determine whether or not cooling priority control is required. [Diagram 3] 4 is a flowchart showing an example of a process executed by an ECU 22 to determine whether or not target speed limit control is required. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An electric vehicle 10 according to the embodiment will be described with reference to the drawings. As an example, the electric vehicle 10 according to the embodiment is a so-called battery electric vehicle (BEV). Note that the configuration described in the embodiment is not limited to battery electric vehicles, and can be similarly adopted in other types of electric vehicles.

[0013] As shown in Fig. 1, an electric vehicle 10 includes a power unit 14 having a motor 12, a battery 16, an inverter 18, a cooling device 20, an ECU (Electronic Control Unit) 22, a navigation system 24, and an operation panel 26. The battery 16 is a high-voltage battery. Note that high voltage here means an operating voltage exceeding 60 V DC. The battery 16 has multiple built-in secondary battery cells, which may be, for example, lithium-ion cells.

[0014] The motor 12 is a device that drives wheels (not shown) of the electric vehicle 10 by power supplied from the battery 16. The motor 12 is electrically connected to the battery 16 and mechanically connected to the wheels. Although not particularly limited, the motor 12 is a three-phase AC motor. The wheels driven by the motor 12 may be the front wheels or the rear wheels. As an example, in the electric vehicle 10 of this embodiment, the motor 12 is connected to a pair of front wheels via a reduction gear and a differential device. Note that, in another embodiment, the motor 12 may be a so-called in-wheel motor. In this case, the electric vehicle 10 can be provided with a plurality of motors 12 according to the number of drive wheels.

[0015] The power unit 14 is a device that has the motor 12 and generates power necessary to drive the electric vehicle 10. There are no particular limitations on the specific configuration of the power unit 14. As an example, the power unit 14 in this embodiment may include the motor 12, a reduction gear, and a differential gear.

[0016] The inverter 18 converts the DC power supplied from the battery 16 into three-phase AC power supplied to the motor 12. At this time, the inverter 18 can freely control the rotation speed of the motor 12 by changing the frequency of the three-phase AC power supplied to the motor 12. Furthermore, the specific configuration of the inverter 18 is not particularly limited. As an example, the inverter 18 in this embodiment has a plurality of switching elements and a freewheeling diode connected in parallel to each switching element.

[0017] The cooling device 20 is a device that cools the power unit 14 having the motor 12 and / or the battery 16. The cooling device 20 is electrically connected to the ECU 22, and the operation of the cooling device 20 is controlled by the ECU 22. The specific configuration of the cooling device 20 is not particularly limited. As an example, the cooling device 20 in this embodiment may be a water-cooled type. That is, the cooling device 20 circulates coolant between piping arranged inside (or in the vicinity of) the power unit 14 and / or the battery 16 and a heat exchanger such as a radiator. As a result, the heat generated in the power unit 14 and / or the battery 16 is recovered by the coolant, and the heat recovered by the coolant is released to the outside air in the heat exchanger.

[0018] The ECU 22 controls the operation of each part of the electric vehicle 10, including the inverter 18 and the cooling device 20. The ECU 22 may be a single ECU or a combination of multiple ECUs. The ECU 22 is communicatively connected to a navigation system 24 and an operation panel 26. The ECU 22 receives signals output from these devices 24, 26, and outputs control commands to the inverter 18 and / or the cooling device 20 in response to the received signals. The ECU 22 in this embodiment has at least a driving control function for controlling the operations of the motor 12 and the battery 16, and a cooling control function for controlling the operation of the cooling device 20. The specific configuration of the ECU 22 is not particularly limited.

[0019] The navigation system 24 is a device that provides route guidance to a set destination. The navigation system 24 searches for multiple routes from the current location of the electric vehicle 10 to the set destination, and provides guidance to the destination according to a route selected from among them. The navigation system 24 in this embodiment has a function of determining whether the set destination is a racing circuit or not. The navigation system 24 instructs the ECU 22 on the result of the determination, and the ECU 22 appropriately controls the operation of the inverter 18 and the cooling device 20 according to the result of the instruction. The specific configuration of the navigation system 24 is not particularly limited.

[0020] The operation panel 26 is a device that is operated by a passenger of the electric vehicle 10 and that teaches the ECU 22 a signal operated by the passenger to activate a preset function as necessary. A switch for activating ACC (adaptive cruise control) may be arranged on the operation panel 26. The ACC is a function for automatically adjusting the vehicle speed of the electric vehicle 10 according to a set target speed while maintaining a sufficient distance from a preceding vehicle. The specific configuration and arrangement of the operation panel 26 are not particularly limited. As one example, the operation panel 26 in this embodiment may be arranged on the steering wheel or on the center console inside the vehicle, and the activation switches for each function may be a touch panel or a button.

[0021] With reference to Fig. 2, a process of determining whether or not cooling priority control is required, which is executed by the ECU 22, will be described. When the destination of the electric vehicle 10 is set to a circuit, the ECU 22 repeatedly executes a series of control procedures shown in Fig. 2. First, the ECU 22 determines whether or not the destination set by the navigation system 24 is a circuit (S10). If the set destination is a circuit (S10: Yes), the ECU 22 determines whether or not guidance to the circuit has been started by the navigation system 24 (S12). If the set destination is not a circuit (S10: No), the ECU 22 issues a command to the cooling device 20 to execute a normal mode in which the cooling target temperature of the battery and / or the power unit is set to a preset normal value (S19).

[0022] When the navigation system 24 starts guidance to the circuit (S12: Yes), the ECU 22 judges whether or not cooling priority control (cooling priority mode or circuit mode) is executable (S14). The cooling priority control (cooling priority mode or circuit mode) sets the cooling target temperature of the battery and / or power unit to a value lower than that in the normal mode. When the navigation system 24 has not started guidance to the circuit (S12: No), the ECU 22 issues a command to the cooling device 20 to execute the normal mode, which sets the cooling target temperature of the battery and / or power unit to a preset normal value (S19).

[0023] If the cooling priority control (cooling priority mode or circuit mode) can be executed (S14: Yes), the ECU 22 displays a selection screen for whether or not to operate the cooling priority control on the display of the navigation system 24, and determines whether or not there is a driver's request to operate the control (S16). If the cooling priority control (cooling priority mode or circuit mode) cannot be executed (S14: No), the ECU 22 issues a command to the cooling device 20 to execute a normal mode in which the cooling target temperature of the battery and / or the power unit is set to a preset normal value (S19).

[0024] If the driver requests the operation of the cooling priority control (S16: Yes), the ECU 22 issues a command to the cooling device 20 to execute the cooling priority control (cooling priority mode or circuit mode) (S18). The reduction amount of the cooling target temperature set in (S18) can be set to any value. If the driver does not request the operation of the cooling priority control (S16: No), the ECU 22 issues a command to the cooling device 20 to execute the normal mode (S19). That is, the cooling target temperature of the battery and / or the power unit is set to a preset value for normal time.

[0025] When the ECU 22 executes the process up to step S18 or S19, the series of control procedures shown in Fig. 2 is completed (END). The ECU 22 repeatedly executes the series of control procedures shown in Fig. 2 to continuously execute the process of determining whether or not cooling priority control is required.

[0026] A process for determining whether or not target speed limit control is required, which is executed by the ECU 22, will be described with reference to Fig. 3. The ECU 22 repeatedly executes a series of control procedures shown in Fig. 3 while the electric vehicle 10 is traveling. First, the ECU 22 determines whether or not cooling priority control is being executed (S20).

[0027] If the cooling priority control is being executed (S20: Yes), the ECU 22 determines whether the ACC is operating (S22). If the cooling priority control is not being executed (S20: No), the ECU 22 ends the process of determining whether the target speed limit control is required (END).

[0028] If the ACC is operating (S22: Yes), the ECU 22 determines whether or not a value obtained by subtracting the oil temperature detected by the cooling device 20 from a preset target oil temperature is equal to or greater than a preset threshold value (S24). If the ACC is not operating (S22: No), the ECU 22 maintains the state in which the cooling priority control is being executed and ends the process of determining whether or not target speed limit control is required (END).

[0029] If the value obtained by subtracting the detected oil temperature value from the preset target oil temperature value is equal to or greater than the preset threshold value (S24: Yes), the ECU 22 displays a selection screen for whether or not to activate the target speed limit control on the display of the navigation system 24, and determines whether or not there is a driver's request for activation (S26). If the value obtained by subtracting the detected oil temperature value from the preset target oil temperature value is less than the preset threshold value (S24: No), the ECU 22 maintains the execution of the cooling priority control and the ACC activated state, and completes the series of control procedures shown in Fig. 3 (END). The ECU 22 returns to the process of step S20 shown in Fig. 3, and repeats the series of control procedures shown in Fig. 3.

[0030] If there is a request from the driver to activate the target speed limit control (S26: Yes), the ECU 22 executes the target speed limit control (S28). In the target speed limit control, the target speed is reset to a speed lower than the currently set target speed and the ACC is activated. Note that the reduction width of the target speed reset in step S28 can be set to any value.

[0031] If there is no request from the driver to activate the target speed limit control (S26: No), the ECU 22 maintains the execution of the cooling priority control and the normal ACC, and completes the series of control procedures shown in FIG. 3 (END).

[0032] When the ECU 22 executes the process up to step S28, the series of control procedures shown in Fig. 3 is completed (END). The ECU 22 repeatedly executes the series of control procedures shown in Fig. 3 to continuously execute the process of determining whether or not target speed limit control is required. [Explanation of symbols]

[0033] 10: electric vehicle, 12: motor, 14: power unit, 16: battery, 18: inverter, 20: cooling device, 22: ECU, 24: navigation system, 26: operation panel

Claims

[Claim 1] An electric vehicle, a power unit having a motor for driving wheels; a battery for supplying power to the motor; a cooling device that cools at least one of the battery or the power unit; A cooling control device that controls the operation of the cooling device in accordance with a set target temperature; A navigation system in which the destination of the electric vehicle is set; Equipped with The navigation system has a function of determining whether the destination is a racing circuit or not, The cooling control device executes a specific control mode in which the target temperature is set to a value lower than normal when the navigation system determines that the destination is a racing track. Electric car.

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