Vehicle, vehicle control method, and program
Patent Information
- Application Number
- PCT/JP2025/012938
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-03-28
- Publication Date
- 2026-10-01
Smart Images
Figure JP2025012938_01102026_PF_FP_ABST
Abstract
Description
Vehicle, vehicle control method, and program
[0001] The present invention relates to a vehicle, a vehicle control method, and a program.
[0002] In recent years, efforts toward the realization of a low-carbon or decarbonized society have become active, and research and development on electrification technologies are being conducted for vehicles as well, in order to reduce CO₂ emissions and improve energy efficiency.
[0003] The power conversion device described in Patent Document 1 is mounted in an automobile using a motor as a drive source, and supplies electric power to the motor. When the output current from the power conversion device exceeds a predetermined value and this state continues for a predetermined period of time, the output current is limited, and the predetermined period of time is set longer as the temperature of the cooling body is lower.
[0004] Japanese Unexamined Patent Publication No. 2006-025493
[0005] In the power conversion device described in Patent Document 1, the allowable duration for which the output current exceeds a predetermined value is set based on the temperature of the cooling body. For this reason, even when there is remaining capacity for cooling the power conversion device, the output current may be limited, and there is a risk that sufficient driving force cannot be obtained.
[0006] One object of the present invention is to utilize the remaining cooling capacity to bring out the performance of the power conversion device and obtain sufficient driving force.
[0007] A vehicle according to one aspect of the present invention comprises: a power converter that supplies power to a power source of the vehicle; a first circulation path that circulates a first temperature-controlled medium, including a first flow path that passes through the power converter and a second flow path that bypasses the power converter; a pump that adjusts the flow rate of the first temperature-controlled medium flowing through the first circulation path; a valve that adjusts the flow rate distribution of the first temperature-controlled medium to the first flow path and the second flow path; and a control unit that controls the pump and the valve, wherein the control unit performs a drive force limiting control that limits the driving force of the vehicle according to the temperature of the first temperature-controlled medium flowing through the first circulation path or the temperature of the power converter, and in the drive force limiting control, an upper limit value of the driving force of the vehicle for each temperature of the first temperature-controlled medium flowing through the first circulation path or for each temperature of the power converter is set based on at least one of the state of the pump and the state of the valve.
[0008] Furthermore, a vehicle control method according to one aspect of the present invention is a vehicle control method comprising: a power converter that supplies power to a vehicle's drive source; a first circulation path that circulates a first temperature-controlled medium, including a first flow path that passes through the power converter and a second flow path that bypasses the power converter; a pump that adjusts the flow rate of the first temperature-controlled medium flowing through the first circulation path; and a valve that adjusts the flow rate distribution of the first temperature-controlled medium to the first flow path and the second flow path, wherein a processor mounted on the vehicle performs a drive force limiting control that limits the driving force of the vehicle according to the temperature of the first temperature-controlled medium flowing through the first circulation path or the temperature of the power converter, and in the drive force limiting control, an upper limit value of the driving force of the vehicle for each temperature of the first temperature-controlled medium flowing through the first circulation path or for each temperature of the power converter is set based on at least one of the state of the pump and the state of the valve.
[0009] Furthermore, a program according to one aspect of the present invention causes a processor to execute the vehicle control method.
[0010] According to the present invention, the cooling surplus can be utilized to maximize the performance of the power conversion device, thereby obtaining sufficient driving force.
[0011] This is a block diagram of an example vehicle for illustrating embodiments of the present invention. This is a table showing examples of setting the upper limit of the vehicle's driving force in driving force limiting control. This is a graph schematically showing an example of the change in the upper limit of the vehicle's driving force in driving force limiting control. This is a flowchart of the process performed by the control unit, including setting the upper limit of the vehicle's driving force in driving force limiting control. This is a flowchart of the process performed by the control unit, including setting the upper limit of the vehicle's driving force in driving force limiting control. This is a flowchart of the process performed by the control unit, including setting the upper limit of the vehicle's driving force in driving force limiting control. This is a graph schematically showing another example of the change in the upper limit of the vehicle's driving force in driving force limiting control.
[0012] An example of a vehicle for illustrating embodiments of the present invention will be described based on the attached drawings.
[0013] The vehicle 1 shown in Figure 1 is an electric vehicle, such as an electric car or a hybrid vehicle (including a plug-in hybrid vehicle). The vehicle 1 comprises a motor 2 as a drive source, a battery, and an inverter 4. The inverter 4 includes a plurality of switching elements, which convert the DC current from the battery to AC current by turning the plurality of switching elements ON / OFF, and the converted AC current is supplied to the motor 2 to rotate the motor 2, thereby outputting the driving force of the vehicle 1 to the motor 2. The inverter 4 is configured to acquire the output request for driving force to the motor 2 based on the acceleration and deceleration operations of the occupants of the vehicle 1, and to supply power to the motor 2 according to the output request.
[0014] Vehicle 1 includes an inverter 4 and a cooling circuit for cooling a drive unit including a motor 2. The drive unit may also include a transmission, and in the case of a hybrid vehicle, it may further include a generator.
[0015] The cooling circuit includes a first circulation path 11 for circulating a first temperature-controlled medium for cooling the inverter 4, and a second circulation path 12 for circulating a second temperature-controlled medium for cooling the drive unit. The first temperature-controlled medium is, for example, water, and may have ethylene glycol or propylene glycol added from the viewpoint of antifreeze, corrosion prevention, rust prevention, etc. The second temperature-controlled medium is, for example, oil.
[0016] Vehicle 1 further comprises a first pump 13, a second pump 14, a valve 15, a heat exchanger 16, a radiator 17, an active grill shutter 18, and a control unit 19 as elements constituting the cooling circuit.
[0017] The first circulation path 11 includes a first flow path 20 that passes through the inverter 4 and a second flow path 21 that bypasses the inverter 4. The first flow path 20 and the second flow path 21 branch off at a branching section 22 in the first circulation path 11 and merge at a merging section 23, with a common flow path 24 between the merging section 23 and the branching section 22.
[0018] The first pump 13 is located in the common flow path 24, and a tank 25 for temporarily storing the first temperature-controlled medium is provided on the suction side of the first pump 13 in the common flow path 24. The first pump 13 changes its discharge rate according to its operating duty cycle and adjusts the flow rate of the first temperature-controlled medium flowing through the first circulation path 11. The first pump 13 may be an electric pump equipped with a motor, or a mechanical pump driven by an engine.
[0019] Valve 15 is provided at the inlet to the second flow path 21 in the branch section 22. Valve 15 changes the flow rate of the first temperature-controlled medium flowing into the second flow path 21 according to its opening degree, and adjusts the flow rate distribution of the first temperature-controlled medium to the first flow path 20 and the second flow path 21. In this example, valve 15 is switchable between a closed state and an open state. When valve 15 is closed, all of the first temperature-controlled medium flowing through the first circulation path 11 is distributed to the first flow path 20. When valve 15 is open, a portion of the first temperature-controlled medium flowing through the first circulation path 11 is distributed to the second flow path 21, and the remainder is distributed to the first flow path 20.
[0020] The radiator 17 is located in the common flow path 24 between the first pump 13 and the branch section 22. The radiator 17 exchanges heat between the first temperature-controlled medium flowing through the common flow path 24 and the outside air, thereby cooling the first temperature-controlled medium. A temperature sensor 26 is provided on the outlet side of the radiator 17 in the common flow path 24, and the temperature sensor 26 detects the temperature of the first temperature-controlled medium that has passed through the radiator 17.
[0021] The active grille shutter 18 is provided at the air intake of the front grille and / or front bumper of the vehicle 1. The active grille shutter 18 is opened and closed to regulate the outside air flowing into the radiator 17.
[0022] The second pump 14 is located in the second circulation path 12, and a tank 27 for temporarily storing the second temperature-controlled medium is provided on the suction side of the second pump 14 in the second circulation path 12. The second pump 14 changes its discharge rate according to its operating duty cycle, adjusting the flow rate of the second temperature-controlled medium flowing through the second circulation path 12. The second pump 14 may be an electric pump equipped with a motor, or a mechanical pump driven by an engine. A temperature sensor 28 is provided in the tank 27, and the temperature sensor 28 detects the temperature of the second temperature-controlled medium stored in the tank 27.
[0023] The heat exchanger 16 is installed across the second flow path 21 and the second circulation path 12 of the first circulation path 11. The heat exchanger 16 performs heat exchange between the first temperature-controlled medium flowing through the second flow path 21 and the second temperature-controlled medium flowing through the second circulation path 12, thereby cooling the second temperature-controlled medium.
[0024] The control unit 19 is mainly composed of a processor and, by executing a predetermined program, controls the operating duty cycle of the first pump 13, the operating duty cycle of the second pump 14, the opening and closing of the valve 15, and the opening and closing of the active grill shutter 18 based on the temperature of the first temperature control medium detected by the temperature sensor 26 and the temperature of the second temperature control medium detected by the temperature sensor 28.
[0025] For example, if the inverter 4 increases the power supplied to the motor 2 in response to an increase in the output demand for driving force to the motor 2, the inverter 4 will generate heat, and the temperature of the first temperature control medium that cools the inverter 4 will rise. In response to the rise in temperature of the first temperature control medium, the control unit 19 increases the operating duty cycle of the first pump 13, increases the flow rate of the first temperature control medium flowing through the first flow path 20, and strengthens the cooling of the inverter 4. The operating duty cycle of the first pump 13 may change continuously, but in this example, it is set to change in steps such as low duty, medium duty, and high duty.
[0026] When the inverter 4 increases the power supplied to the motor 2, and the motor 2 increases its output, the motor 2 generates heat, and the temperature of the second temperature-controlled medium that cools the motor 2 rises. In response to the rise in temperature of the second temperature-controlled medium, the control unit 19 increases the operating duty cycle of the second pump 14, increasing the flow rate of the second temperature-controlled medium flowing through the second circulation path 12, thereby strengthening the cooling of the motor 2. Also, in response to the rise in temperature of the second temperature-controlled medium, the control unit 19 opens the valve 15, distributing a portion of the first temperature-controlled medium flowing through the first circulation path 11 to the second flow path 21, and cooling the second temperature-controlled medium by heat exchange between the first and second temperature-controlled medium in the heat exchanger 16.
[0027] In response to the temperature rise of the first temperature-controlled medium due to the cooling of the inverter 4 and the second temperature-controlled medium, the control unit 19 opens the active grill shutter 18 to increase the heat exchange between the first temperature-controlled medium and the outside air in the radiator 17, thereby promoting the cooling of the first temperature-controlled medium.
[0028] Furthermore, the control unit 19 can perform power-saving control to limit the vehicle's driving force and prevent overheating and damage to the switching elements of the inverter 4, based on the temperature of the first temperature-controlled medium or the temperature of the inverter 4. In power-saving control, the control unit 19 sets an upper limit value for the vehicle's driving force for each temperature of the first temperature-controlled medium flowing through the first circulation path 11 or for each temperature of the inverter 4, based on at least one of the state of the first pump 13 and the state of the valve 15.
[0029] By setting the upper limit of the vehicle's driving force in power-saving control based on the state of the first pump 13 and the state of the valve 15, it is possible to suppress a decrease in output while retaining cooling capacity for the inverter 4. This makes it possible to achieve both the output requirement and the suppression of the temperature rise of the inverter 4. The limit on the vehicle's driving force may be a limitation on the power that the inverter 4 supplies to the motor 2, or a limitation on the driving force output by the motor 2. The following explanation will use the limitation on the power that the inverter 4 supplies to the motor 2 as an example.
[0030] Figure 2 shows an example of setting an upper limit on power consumption.
[0031] As shown in Figure 2, the control unit 19 sets the power limit to a first upper limit value Wa1 when it can increase the discharge rate of the first pump 13 and the flow rate of the first temperature-controlled medium in the first flow path 20 can be increased by the valve 15 to a predetermined amount or more. In this example, where the operating duty cycle of the first pump 13 changes in stages from low duty, medium duty, and high duty, being able to increase the discharge rate of the first pump 13 means operating the first pump 13 in high duty. Also, in this example, where the valve 15 can be switched between a closed state and an open state, being able to increase the flow rate of the first temperature-controlled medium in the first flow path 20 to a predetermined amount or more by the valve 15 means closing the valve 15. On the other hand, if the control unit 19 cannot increase the discharge rate of the first pump 13 and the flow rate of the first temperature-controlled medium in the first flow path 20 cannot be increased by the valve 15 to a predetermined amount or more, it sets the power limit to a second upper limit value Wa2, which is lower than the first upper limit value Wa1 (Wa2 < Wa1).
[0032] Furthermore, the control unit 19 sets the power limit to the third upper limit value Wa3 if it can increase the discharge amount of the first pump 13 and the flow rate of the first temperature-controlled medium in the first flow path 20 cannot be increased to a predetermined amount by the valve 15, and sets the power limit to the fourth upper limit value Wa4 if it cannot increase the discharge amount of the first pump 13 and the flow rate of the first temperature-controlled medium in the first flow path 20 can be increased to a predetermined amount by the valve 15. The third upper limit value Wa3 and the fourth upper limit value Wa4 are higher than the second upper limit value Wa2 and lower than the first upper limit value Wa1 (Wa2 < Wa3 and Wa4 < Wa1).
[0033] When the flow rate of the first temperature-controlled medium flowing through the first flow path 20 can be increased by the first pump 13 and valve 15, the upper limit of the power for each temperature of the first temperature-controlled medium flowing through the first circulation path 11 or for each temperature of the inverter 4 can be increased. This suppresses the execution of power-saving control while the inverter 4 has cooling capacity remaining, making it possible to utilize the inverter 4's capacity to the fullest.
[0034] Preferably, the third upper limit value Wa3 is higher than the fourth upper limit value Wa4 (Wa2 < Wa4 < Wa3 < Wa1). The opening and closing of valve 15 is directly related to the cooling of the second temperature-controlled medium that cools the motor 2, while the operating duty cycle of the first pump 13 is less constrained by the cooling of the second temperature-controlled medium than that of valve 15, allowing for more flexible settings. Therefore, when the flow rate of the first temperature-controlled medium can be increased by the first pump 13, setting the power upper limit relatively high further suppresses the execution of power-saving control while leaving cooling capacity for the inverter 4, making it possible to utilize the inverter 4's capacity to the fullest.
[0035] Figure 3 schematically shows the change in power supplied by the inverter 4 to the motor 2, which is limited by power-saving control.
[0036] When the temperature of the first temperature-controlled medium detected by the temperature sensor 26 reaches a predetermined control start temperature, the control unit 19 performs power-saving control. In power-saving control, as the temperature of the first temperature-controlled medium rises from the control start temperature, the control unit 19 lowers the upper limit of the power that the inverter 4 can supply to the motor 2. The upper limit of power determines the upper limit of the driving force that the motor 2 can output. Let W0 be the upper limit of power that the inverter 4 can supply to the motor 2 before the start of power-saving control. When the temperature of the first temperature-controlled medium reaches Tupper, the upper limit of power becomes W1 (W1 < W0), and the upper limit of power is fixed at W1 when the temperature of the first temperature-controlled medium is Tupper or higher.
[0037] The control unit 19 sets the power limit along the first change curve C1, shown as a solid line in Figure 2, when it can increase the discharge rate of the first pump 13 and the flow rate of the first temperature-controlled medium in the first flow path 20 can be increased to a predetermined amount or more by the valve 15. The control unit 19 sets the power limit along the second change curve C2, shown as a dashed line in Figure 2, when it cannot increase the discharge rate of the first pump 13 and the flow rate of the first temperature-controlled medium in the first flow path 20 can be increased to a predetermined amount or more by the valve 15. The control unit 19 sets the power limit along the third change curve C3, shown as a dashed line in Figure 2, when it can increase the discharge rate of the first pump 13 and the flow rate of the first temperature-controlled medium in the first flow path 20 can be increased to a predetermined amount or more by the valve 15. Furthermore, the control unit 19 sets the power limit along the fourth change curve C4, shown as a double dashed line in Figure 2, when it cannot increase the discharge rate of the first pump 13 and the flow rate of the first temperature-controlled medium in the first flow path 20 can be increased to a predetermined amount or more by the valve 15.
[0038] For a given temperature T, the upper limit of power set based on the first change curve C1 is the first upper limit value Wa1, the upper limit of power set based on the second change curve C2 is the second upper limit value Wa2, the upper limit of power set based on the third change curve C3 is the third upper limit value Wa3, and the upper limit of power set based on the fourth change curve C4 is the fourth upper limit value Wa4, where Wa2 < Wa4 < Wa3 < Wa1. For example, according to the first change curve C1, the rate of decrease in the upper limit of power with respect to the temperature rise of the first temperature control medium near the Tupper is relatively large, but the upper limit of power is kept at a relatively high value over a relatively long temperature range after the start of control. During that time, even if the output demand for driving force to the motor 2 temporarily increases due to, for example, the acceleration and deceleration operation of the occupant, it is possible to respond to the output demand by utilizing the cooling surplus capacity of the inverter 4.
[0039] In the example shown in Figure 3, the upper limit of the power supplied by the inverter 4 to the motor 2 was described as being set in relation to the temperature of the first temperature control medium. However, the temperature of the inverter 4 and the temperature of the first temperature control medium that cools the inverter 4 are related, and therefore, the upper limit of the power may also be set in relation to the temperature of the inverter 4.
[0040] Figures 4 to 7 show an example of the process performed by the control unit 19, including setting the upper limit of power in power saving control.
[0041] Motor 2 is cooled by a second temperature-controlled medium flowing through a second circulation path 12, and the second temperature-controlled medium is cooled by heat exchange with the first temperature-controlled medium in the heat exchanger 16. Valve 15 regulates the flow rate of the first temperature-controlled medium flowing through a second flow path 21 passing through the heat exchanger 16, and the opening and closing of valve 15 is related to the temperature of the second temperature-controlled medium. Therefore, the temperature of the second temperature-controlled medium is related to the cooling capacity of the inverter 4. Also, as the driving force output by motor 2 increases, the heat generated by motor 2 increases, and the temperature of the second temperature-controlled medium rises. Therefore, the output requirement for driving force to motor 2 is also related to the cooling capacity of the inverter 4. The control unit 19 sets the upper limit of power in power-saving control, taking into consideration the temperature of the second temperature-controlled medium and the output requirement for driving force to motor 2.
[0042] Furthermore, the first temperature control medium, which cools the inverter 4 and the second temperature control medium, is cooled by heat exchange with the outside air in the radiator 17. When the active grill shutter 18 is opened, the cooling of the first temperature control medium in the radiator 17 is promoted. However, from the viewpoint of suppressing a decrease in the aerodynamic performance of the vehicle 1, the control unit 19 opens the active grill shutter 18 when forced cooling of the first temperature control medium is necessary, for example, and basically keeps the active grill shutter 18 closed.
[0043] First, when vehicle 1 starts moving, the control unit 19 closes the active grill shutter 18 and operates the first pump 13 in low duty, medium duty, or high duty cycle according to the temperature TW of the first temperature control medium (step S1). Then, the control unit 19 obtains the temperature TATF of the second temperature control medium and determines whether the temperature TATF of the second temperature control medium is equal to or greater than the first predetermined temperature TATF1 (step S2).
[0044] When the temperature TATF of the second temperature adjustment medium is less than the first predetermined temperature TATF1 (step S2-No), the control unit 19 determines that the priority of cooling the motor 2 is low, that is, the valve 15 can be closed (step S10), and sets the upper limit of electric power in power save control. In setting the upper limit of electric power, the control unit 19 sets the upper limit of electric power for each temperature of the first temperature adjustment medium to be higher as the temperature TATF of the second temperature adjustment medium is lower, and sets the upper limit of electric power for each temperature of the first temperature adjustment medium to be lower as the temperature TATF of the second temperature adjustment medium is higher.
[0045] For example, when a first threshold TATFth1 and a second threshold TATFth2 (TATFth1 < TATFth2 < TATF1) related to the temperature TATF of the second temperature adjustment medium are used, and the temperature TATF of the second temperature adjustment medium is less than the first threshold TATFth1 (step S11-Yes), the upper limit of electric power is set to Wb1 (step S12). When the temperature TATF of the second temperature adjustment medium is not less than the first threshold TATFth1 and less than the second threshold TATFth2 (step S13-Yes), the upper limit of electric power is set to Wb2 lower than Wb1 (Wb1 > Wb2) (step S14). Then, when the temperature TATF of the second temperature adjustment medium is not less than the second threshold TATFth2 (step S13-No), the upper limit of electric power is set to Wb3 higher than the second threshold Wa2 and lower than Wb2 (Wb1 > Wb2 > Wb3 > Wa2) (step S15).
[0046] The temperature of the motor 2 rises following the temperature rise of the inverter 4. When the temperature TATF of the second temperature adjustment medium that cools the motor 2 is high, the temperature rise can be suppressed by lowering the upper limit of electric power in power save control from an early stage (a low temperature). Accordingly, both the inverter 4 and the motor 2 are thermally protected, and the execution of power save control in a state where a surplus cooling capacity of the inverter 4 remains can be suppressed.
[0047] Furthermore, for a predetermined period after the start of power save control, the upper limit value of electric power may be set to be the same regardless of the temperature TATF of the second temperature adjustment medium. In the example shown in FIG. 8, from a predetermined control start temperature Ts at which power save control is started, for the predetermined temperature interval ΔT, the first change curve C1, the third change curve C3, and the fourth change curve C4 coincide with each other. That is, when the discharge amount of the first pump 13 can be increased, and / or the flow rate of the first temperature adjustment medium in the first flow path 20 can be adjusted to a predetermined amount or more by the valve 15, the upper limit value of electric power is the same. Instead of the temperature interval ΔT, the upper limit value of electric power may be set to be the same for a predetermined time after the start of power save control.
[0048] When setting the upper limit of electric power based on the temperature of the second temperature adjustment medium, setting the same upper limit value of electric power for the predetermined period makes it possible to prioritize the output of the inverter 4 in the initial stage of power save control. Therefore, it is possible to respond to an output request, and when the motor 2 requires cooling, appropriate cooling can be performed by the power save control.
[0049] Returning to step S2, when the temperature TATF of the second temperature adjustment medium is equal to or higher than a first predetermined temperature TATF1 (step S2 - Yes), the control unit 19 further determines whether or not the temperature TATF of the second temperature adjustment medium is lower than a second predetermined temperature TATF2 (TATF1 < TATF2) that is higher than the first predetermined temperature TATF1 (step S3).
[0050] When the temperature TATF of the second temperature adjustment medium is equal to or higher than the second predetermined temperature TATF2 (step S3 - No), the control unit 19 determines that the priority of cooling the motor 2 is high, opens the valve 15 to increase the flow rate of the first temperature adjustment medium flowing through the second flow path 21, and sets the upper limit of electric power in power save control (step S20). Since the valve 15 is brought into the open state, the control start temperature set in step S20 becomes a second upper limit value Wa2 or a third upper limit value Wa3 in accordance with the operation duty of the first pump 13 determined based on the temperature TW of the first temperature adjustment medium.
[0051] When the temperature of the second temperature control medium is high, above the second predetermined temperature TATF2, priority is given to cooling the motor 2, the valve 15 is opened to increase the flow rate of the first temperature control medium through the second flow path 21, and an upper limit is set on the power in power saving control. This protects the inverter 4 and motor 2 from heat, and prevents power saving control from being performed while there is still cooling capacity remaining for the inverter 4.
[0052] Next, the control unit 19 determines whether the requested drive force output MotTq for the motor 2 is equal to or greater than a predetermined drive force MotTq1 (step S21). If the requested drive force MotTq is less than the predetermined drive force MotTq1 (step S21-No), the control unit 19 controls the first pump 13 and the valve 15 in normal operation (step S22). In normal operation, the control unit 19 operates the first pump 13 in low duty, medium duty, or high duty according to the temperature TW of the first temperature control medium. The control unit 19 also opens the valve 15 when the temperature TATF of the second temperature control medium reaches a third predetermined temperature TATF3 (TATF1 < TATF3 < TATF2) which is higher than the first predetermined temperature TATF1 and lower than the second predetermined temperature TATF2.
[0053] If the output request MotTq is equal to or greater than the predetermined driving force MotTq1 (step S21-Yes), the control unit 19 determines whether the temperature TW of the first temperature-controlled medium is equal to or greater than the second temperature Ta2 (step S23). If the temperature TW of the first temperature-controlled medium is less than the second temperature Ta2 (step S23-No), the control unit 19 controls the first pump 13 and valve 15 normally (step S22). On the other hand, if the temperature TW of the first temperature-controlled medium is equal to or greater than the predetermined control start temperature Ts for starting power-saving control (step S23-Yes), the control unit 19 forces the first pump 13 to operate on high duty to increase the flow rate of the first temperature-controlled medium flowing through the first circulation path 11 and sets an upper limit for power in power-saving control (step S24). Since the first pump 13 is operated on high duty and the valve 15 is in the open state, the upper limit for power set in step S24 becomes the third upper limit value Wa3. The control unit 19 maintains the operating duty cycle of the first pump 13 at high duty cycle until the output request MotTq falls below a predetermined driving force MotTq1, or the temperature TW of the first temperature control medium falls below a predetermined control start temperature Ts.
[0054] Returning to step S3, if the temperature TATF of the second temperature control medium is less than the second predetermined temperature TATF2 (step S3-Yes), the control unit 19 determines whether the output request MotTq for the driving force to the motor 2 is greater than or equal to the predetermined driving force MotTq1 (step S4). If the output request MotTq is less than the predetermined driving force MotTq1 (step S4-No), the control unit 19 controls the first pump 13 and valve 15 normally (step S5).
[0055] If the output request MotTq is equal to or greater than the predetermined driving force MotTq1 (Step S4 - Yes), the control unit 19 determines whether the temperature TW of the first temperature-controlled medium is equal to or greater than the predetermined control start temperature Ts for starting power-saving control (Step S6). If the temperature TW of the first temperature-controlled medium is less than the control start temperature Ts (Step S4 - No), the control unit controls the first pump 13 and valve 15 normally (Step S5). On the other hand, if the temperature TW of the first temperature-controlled medium is equal to or greater than the control start temperature Ts (Step S6 - Yes), the control unit 19 determines that cooling the inverter 4 has a high priority and further determines whether the temperature TW of the first temperature-controlled medium is equal to or greater than the predetermined temperature TW1 (Ts < TW1) which is higher than the control start temperature Ts (Step S7).
[0056] If the temperature TW of the first temperature-controlled medium is equal to or greater than a predetermined temperature TW1 (step S7-Yes), the control unit 19 forces the first pump 13 to operate on high duty cycle and closes the valve 15 to increase the flow rate of the first temperature-controlled medium in the first flow path 20, thereby strengthening the cooling of the inverter 4. Then, based on the state of the first pump 13 and the state of the valve 15, the control unit 19 sets an upper limit for power in power-saving control (step S8). Since the operating duty cycle of the first pump 13 is set to high duty cycle and the valve 15 is closed, the upper limit for power set in step S8 becomes the first upper limit value Wa1.
[0057] If the temperature TW of the first temperature-controlled medium is less than a predetermined temperature TW1 (step S7-No), the control unit 19 closes the valve 15 and increases the flow rate of the first temperature-controlled medium in the first flow path 20 using the valve 15 to enhance the cooling of the inverter 4. Then, based on the state of the first pump 13 and the state of the valve 15, the control unit 19 sets an upper limit for power in power-saving control (step S9). Since the valve 15 is in the closed state, the upper limit for power set in step S9 is either a first upper limit value Wa1 or a fourth upper limit value Wa4, depending on the operating duty cycle of the first pump 13 determined based on the temperature TW of the first temperature-controlled medium.
[0058] When a relatively high driving force of MotTq1 or higher is required, the temperature of the inverter 4 tends to rise. In such a situation, the operating duty cycle of the first pump 13 is forcibly increased and / or the valve 15 is forcibly closed, increasing the flow rate of the first temperature-controlled medium in the first flow path 20, and enhancing the cooling of the inverter 4. Then, based on the state of the first pump 13 and the state of the valve 15, the upper limit of power in the power-saving control is set. However, if the temperature of the first temperature-controlled medium is low, the first pump 13 and the valve 15 are normally controlled to provide sufficient cooling performance. This suppresses the power consumption of the first pump 13 and the decrease in the cooling performance of the motor 2 due to the adjustment of the valve 15, while enabling appropriate power-saving control when necessary.
[0059] Next, the control unit 19 determines whether the requested drive force output MotTq for the motor 2 is equal to or greater than a predetermined drive force MotTq1 (step S30). If the requested drive force MotTq is less than the predetermined drive force MotTq1 (step S30-No), the control unit 19 controls the first pump 13 and valve 15 normally (step S31). On the other hand, if the requested drive force MotTq is equal to or greater than the predetermined drive force MotTq1 (step S30-Yes), the control unit 19 maintains the closed state of valve 15 set in step S8 or step S9 for a predetermined period (step S32).
[0060] When a relatively high driving force of MotTq1 or higher is required, maintaining the closed state of the valve 15 for a predetermined period allows priority to be given to cooling the inverter 4. This increases the output driving force and prevents the driving force limiting control from being executed while there is still cooling capacity remaining for the inverter 4 in response to the output request.
[0061] When a predetermined period has elapsed and the temperature TATF of the second temperature-controlled medium has reached or exceeded the second predetermined temperature TATF2 (step S32-Yes), the control unit 19 controls the first pump 13 and valve 15 in normal mode (step S31). By keeping the valve 15 closed, the flow of the first temperature-controlled medium in the second flow path is blocked, and the temperature of the second temperature-controlled medium rises over time. Therefore, on the condition that the temperature of the second temperature-controlled medium reaches or exceeds the second predetermined temperature TATF2, the control of the first pump 13 and valve 15 returns to normal control.
[0062] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and modifications, improvements, etc., can be made as appropriate. This specification includes at least the following matters. Note that the components etc. in parentheses indicate those corresponding to the above embodiments, but the invention is not limited thereto.
[0063] (1) A vehicle comprising: a power converter (inverter 4) that supplies power to a drive source (motor 2) of a vehicle (vehicle 1); a first circulation path (first circulation path 11) that circulates a first temperature-controlled medium, including a first flow path (first flow path 20) that passes through the power converter and a second flow path (second flow path 21) that bypasses the power converter; a pump (first pump 13) that adjusts the flow rate of the first temperature-controlled medium flowing through the first circulation path; a valve (valve 15) that adjusts the flow rate distribution of the first temperature-controlled medium to the first flow path and the second flow path; and a control unit (control unit 19) that controls the pump, the valve, and the power converter, wherein the control unit performs a driving force limiting control that limits the driving force of the vehicle according to the temperature of the first temperature-controlled medium flowing through the first circulation path or the temperature of the power converter, In the aforementioned driving force limiting control, an upper limit value of the driving force of the vehicle is set for each temperature of the first temperature control medium flowing through the first circulation path or for each temperature of the power converter, based on at least one of the state of the pump and the state of the valve.
[0064] According to the vehicle described in (1) above, by setting the upper limit of the vehicle's driving force in the driving force limiting control based on the state of the pump and valves, it is possible to suppress a decrease in output while retaining cooling capacity for the power converter. This makes it possible to achieve both the output requirement and the suppression of the temperature rise of the power converter.
[0065] (2) A vehicle according to (1) above, wherein the control unit sets the upper limit to a first upper limit when it can increase the discharge amount of the pump and can increase the flow rate of the first temperature control medium in the first flow path by the valve, and sets the upper limit to a second upper limit when it cannot increase the discharge amount of the pump and cannot increase the flow rate of the first temperature control medium in the first flow path by the valve, and the first upper limit is greater than the second upper limit.
[0066] According to the vehicle described in (2) above, when the flow rate of the first temperature-controlled medium flowing through the first flow path can be increased by the pump and valve, the upper limit of the power for each temperature of the first temperature-controlled medium flowing through the first circulation path is increased, thereby suppressing the execution of the drive force limit control while the power converter has cooling capacity remaining, and making it possible to make maximum use of the capacity of the power converter.
[0067] (3) The vehicle according to (2) above, wherein the control unit sets the upper limit to a third upper limit that is higher than the second upper limit and lower than the first upper limit when the discharge amount of the pump can be increased and the flow rate of the first temperature control medium in the first flow path cannot be increased by the valve, and sets the upper limit to a fourth upper limit that is higher than the second upper limit and lower than the first upper limit when the discharge amount of the pump cannot be increased and the flow rate of the first temperature control medium in the first flow path can be increased by the valve, and the third upper limit is greater than the fourth upper limit.
[0068] According to the vehicle described in (3) above, when the flow rate of the first temperature control medium can be increased by the pump, setting the upper limit of the power relatively high further suppresses the execution of the drive force limit control while the power converter has cooling capacity remaining, making it possible to make maximum use of the power converter's capacity.
[0069] (4) The vehicle according to (1) above, further comprising: a second circulation path (second circulation path 12) that passes through the drive source and circulates the second temperature control medium; and a heat exchanger (heat exchanger 16) that performs heat exchange between the first temperature control medium flowing through the second circulation path and the second temperature control medium flowing through the second circulation path, wherein the control unit sets the upper limit higher as the temperature of the second temperature control medium decreases.
[0070] According to the vehicle described in (4) above, the temperature of the power converter rises, followed by a rise in the temperature of the drive source. However, when the temperature of the second temperature control medium that cools the drive source is high, the temperature rise can be suppressed by lowering the upper limit of power in the drive force limit control from an early stage (low temperature). This prevents the drive force limit control from being executed while the power converter has cooling capacity remaining, after thermal protection has been applied to both the power converter and the drive source.
[0071] (5) The vehicle according to (4) above, wherein the control unit controls the valve such that when the temperature of the second temperature control medium is above a predetermined temperature, the flow rate of the first temperature control medium in the first flow path decreases and the flow rate of the first temperature control medium in the second flow path increases.
[0072] According to the vehicle described in (5) above, when the temperature of the second temperature control medium is high above a predetermined temperature, priority is given to cooling the drive source, the flow rate of the first temperature control medium flowing through the second channel is increased by a valve, and an upper limit is set on the power in the drive force limit control, thereby protecting the power converter and drive source from heat, and preventing the drive force limit control from being performed while there is cooling capacity remaining for the power converter.
[0073] (6) The vehicle according to (4) above, wherein the control unit keeps the upper limit the same regardless of the temperature of the second temperature control medium for a predetermined period from the start of the driving force limiting control.
[0074] According to the vehicle described in (6) above, when setting the upper limit of the vehicle's driving force based on the temperature of the second temperature control medium, by keeping the upper limit the same for a predetermined period, the output of the power converter can be prioritized in the initial stage of the driving force limit control, thereby enabling it to respond to output requests, and if cooling of the drive source is necessary, it can be appropriately cooled by the driving force limit control.
[0075] (7) The vehicle according to (1) above, wherein the control unit sets the upper limit value based on at least one of the state of the pump and the state of the valve when the output request for driving force to the drive source is equal to or greater than a predetermined driving force.
[0076] According to the vehicle described in (7) above, when a relatively high driving force exceeding a predetermined driving force is required, the temperature of the power converter tends to rise. In such circumstances, by setting an upper limit on the vehicle's driving force in the driving force limiting control based on the pump state and valve state, it is possible to suppress the decrease in power consumption of the pump and the cooling performance of the drive source due to valve adjustment, and to perform appropriate driving force limiting control when necessary.
[0077] (8) The vehicle according to (7) above, wherein the first circulation path includes a common path between the discharge side of the pump and a branching section that branches into the first flow path and the second flow path, and the control unit controls the pump to increase the discharge amount of the pump and / or the valve to increase the flow rate of the first temperature control medium in the first flow path when the output request is equal to or greater than the predetermined driving force and the temperature of the first temperature control medium in the common flow path is equal to or greater than the predetermined temperature.
[0078] According to the vehicle described in (8) above, when a relatively high driving force exceeding a predetermined driving force is required, the temperature of the power converter tends to rise. In such circumstances, the flow rate of the first temperature control medium in the first flow path is increased by the pump and / or valve, and the upper limit of the vehicle's driving force in the driving force limiting control is set based on the state of the pump and the state of the valve. This suppresses the power consumption of the pump and the decrease in the cooling performance of the drive source due to valve adjustment, and allows for appropriate driving force limiting control when necessary.
[0079] (9) The vehicle according to (7) above, wherein the control unit controls the valve for a predetermined period of time such that the flow rate of the first temperature control medium in the first flow path increases when the output request is equal to or greater than the predetermined driving force.
[0080] According to the vehicle described in (9) above, when a relatively high driving force exceeding a predetermined driving force is required, the state of the valve is maintained for a predetermined period such that the flow rate of the first temperature control medium in the first flow path increases, thereby prioritizing the cooling of the power converter. This allows for a larger output driving force and prevents the driving force limiting control from being executed while there is still cooling capacity remaining for the power converter in response to the output request.
[0081] (10) The vehicle according to (1) above, wherein, in the driving force limiting control, the control unit limits the power supplied by the power converter to the drive source, or limits the driving force output by the drive source.
[0082] (11) A vehicle control method comprising: a power converter that supplies power to a vehicle's drive source; a first circulation path that circulates a first temperature-controlled medium, including a first flow path that passes through the power converter and a second flow path that bypasses the power converter; a pump that adjusts the flow rate of the first temperature-controlled medium flowing through the first circulation path; and a valve that adjusts the flow rate distribution of the first temperature-controlled medium to the first flow path and the second flow path, wherein a processor mounted on the vehicle performs a drive force limiting control that limits the driving force of the vehicle according to the temperature of the first temperature-controlled medium flowing through the first circulation path or the temperature of the power converter; and in the drive force limiting control, an upper limit value of the driving force of the vehicle for each temperature of the first temperature-controlled medium flowing through the first circulation path or for each temperature of the power converter is set based on at least one of the state of the pump and the state of the valve.
[0083] (12) A program that causes the processor to execute the vehicle control method described in (11) above.
[0084] The present invention is suitably applicable to electric vehicles such as electric cars and hybrid vehicles (including plug-in hybrid vehicles).
[0085] 1 Vehicle 2 Motor 4 Inverter 11 First circulation path 12 Second circulation path 13 First pump 14 Second pump 15 Valve 16 Heat exchanger 17 Radiator 18 Active grill shutter 19 Control unit 20 First flow path 21 Second flow path 22 Branch section 23 Junction section 24 Common flow path 25 Tank 26 Temperature sensor 27 Tank 28 Temperature sensor
Claims
1. A vehicle comprising: a power converter that supplies power to the vehicle's drive source; a first circulation path that circulates a first temperature-controlled medium, including a first flow path that passes through the power converter and a second flow path that bypasses the power converter; a pump that adjusts the flow rate of the first temperature-controlled medium flowing through the first circulation path; a valve that adjusts the flow rate distribution of the first temperature-controlled medium to the first flow path and the second flow path; and a control unit that controls the pump, the valve, and the power converter, wherein the control unit performs a drive force limiting control that limits the driving force of the vehicle according to the temperature of the first temperature-controlled medium flowing through the first circulation path or the temperature of the power converter, and in the drive force limiting control, sets an upper limit value of the driving force of the vehicle for each temperature of the first temperature-controlled medium flowing through the first circulation path or for each temperature of the power converter, based on at least one of the state of the pump and the state of the valve.
2. A vehicle according to claim 1, wherein the control unit sets the upper limit to a first upper limit when it can increase the discharge amount of the pump and can increase the flow rate of the first temperature-controlled medium in the first flow path by the valve, and sets the upper limit to a second upper limit when it cannot increase the discharge amount of the pump and cannot increase the flow rate of the first temperature-controlled medium in the first flow path by the valve, and the first upper limit is greater than the second upper limit.
3. A vehicle according to claim 2, wherein the control unit sets the upper limit to a third upper limit that is higher than the second upper limit and lower than the first upper limit when the discharge amount of the pump can be increased and the flow rate of the first temperature-controlled medium in the first flow path cannot be increased by the valve, and sets the upper limit to a fourth upper limit that is higher than the second upper limit and lower than the first upper limit when the discharge amount of the pump cannot be increased and the flow rate of the first temperature-controlled medium in the first flow path can be increased by the valve, and the third upper limit is greater than the fourth upper limit.
4. A vehicle according to claim 1, further comprising: a second circulation path that passes through the drive source and circulates a second temperature-controlled medium; a heat exchanger that performs heat exchange between the first temperature-controlled medium flowing through the second circulation path and the second temperature-controlled medium flowing through the second circulation path, wherein the control unit sets the upper limit higher as the temperature of the second temperature-controlled medium decreases.
5. A vehicle according to claim 4, wherein the control unit controls the valve such that when the temperature of the second temperature-controlled medium is above a predetermined temperature, the flow rate of the first temperature-controlled medium in the first flow path decreases and the flow rate of the first temperature-controlled medium in the second flow path increases.
6. A vehicle according to claim 4, wherein the control unit keeps the upper limit the same regardless of the temperature of the second temperature control medium for a predetermined period from the start of the driving force limiting control.
7. A vehicle according to claim 1, wherein the control unit sets the upper limit value based on at least one of the state of the pump and the state of the valve when the output request for driving force to the drive source is equal to or greater than a predetermined driving force.
8. The vehicle according to claim 7, wherein the first circulation path includes a common path between the discharge side of the pump and a branching section that branches into the first flow path and the second flow path, and the control unit controls the pump to increase the discharge amount of the pump and / or the valve to increase the flow rate of the first temperature-controlled medium in the first flow path when the output request is equal to or greater than the predetermined driving force and the temperature of the first temperature-controlled medium in the common flow path is equal to or greater than the predetermined temperature.
9. A vehicle according to claim 7, wherein the control unit controls the valve for a predetermined period of time such that the flow rate of the first temperature control medium in the first flow path increases when the output request is equal to or greater than the predetermined driving force.
10. A vehicle according to claim 1, wherein, in the driving force limiting control, the control unit limits the power supplied by the power converter to the drive source, or limits the driving force output by the drive source.
11. A vehicle control method comprising: a power converter that supplies power to the drive source of a vehicle; a first circulation path that circulates a first temperature-controlled medium, including a first flow path that passes through the power converter and a second flow path that bypasses the power converter; a pump that adjusts the flow rate of the first temperature-controlled medium flowing through the first circulation path; and a valve that adjusts the flow rate distribution of the first temperature-controlled medium to the first flow path and the second flow path, wherein a processor mounted on the vehicle performs a drive force limiting control that limits the driving force of the vehicle according to the temperature of the first temperature-controlled medium flowing through the first circulation path or the temperature of the power converter; and in the drive force limiting control, an upper limit value of the driving force of the vehicle for each temperature of the first temperature-controlled medium flowing through the first circulation path or for each temperature of the power converter is set based on at least one of the state of the pump and the state of the valve.
12. A program that causes a processor to execute the vehicle control method described in claim 11.