control device

Abstract

The present invention provides a control device that can suppress the temperature rise of the object being cooled while suppressing a decrease in drivability. [Solution] The control unit of the control device 7 monitors the temperature detected by the water temperature sensor at specific intervals, holds the monitored temperature, compares a first temperature with a second temperature immediately preceding the first temperature among the multiple temperatures held, and, as a result of the comparison, if the temperature difference between the first temperature and the second temperature is less than a specific value, does not increase the limit amount that restricts the charging output, but increases the limit amount if the temperature difference exceeds a specific value.

Description

Technical Field

[0001] The present disclosure relates to a control device.

Background Art

[0002] Patent Document 1 discloses a cooling system for a HEV (Hybrid Electric Vehicle). The cooling system for the HEV suppresses excessive temperature rise of an inverter, a motor, etc. by radiating heat generated by the inverter, the motor, etc., that is, loss, to the atmosphere through a radiator, which is a radiator, via cooling water. The amount of heat generated by the inverter, the motor, etc. is determined by the motor operating point, and the absolute value of the loss increases as the motor output increases. Since the performance of the radiator varies greatly depending on the amount of air flowing through the radiator, it is important how to increase the running wind. For example, when the vehicle is traveling at about 60 km / h, since there is a lot of running wind, the amount of air flowing through the radiator increases, and the amount of heat exchange between the radiator and the cooling water increases. However, when the vehicle stops or when traveling at a low vehicle speed, the amount of heat exchange decreases in a situation where running wind cannot be expected. Therefore, in such a situation, in order to increase the amount of heat exchange, it is necessary to operate the radiator fan by forcibly operating the fan motor to supplement the air volume.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In situations where the road is narrow and the incline is steep, the vehicle may travel at a low speed of, for example, 10 km / h for extended periods. In such situations, airflow cannot be expected, and the amount of heat dissipated by the radiator may be insufficient to compensate for the losses incurred by the PCU (Power Control Unit) and motor generator that make up the HEV, potentially causing the water temperature to rise. Even in this case, as mentioned above, the airflow can be compensated for by forcibly operating the radiator fan, but in situations where airflow cannot be expected, the radiator fan alone may not be able to compensate for the heat dissipation, and the water temperature may continue to rise. In some cases, the output of the PCU may be limited to protect it, meaning that the object being cooled may enter an emergency state. As a result, drivability may decrease, potentially causing anxiety to the driver. Thus, conventional technology has room for improvement in suppressing the temperature rise of the object being cooled while suppressing the decrease in drivability.

[0005] This disclosure provides a control device that can suppress the temperature rise of the object being cooled while suppressing a decrease in drivability. [Means for solving the problem]

[0006] A control device according to one aspect of the present disclosure includes a control unit that controls the charging output of a generator that generates power to charge a battery mounted on a vehicle, the control unit includes a monitoring unit that monitors the temperature detected by a water temperature sensor that detects the temperature of cooling water circulating between an inverter that drives a rotating electric machine for the vehicle to move and a cooling device that cools the inverter at specific intervals, a holding unit that holds the monitored temperature, a comparison unit that compares a first temperature with a second temperature immediately preceding the first temperature among a plurality of held temperatures, and as a result of the comparison, if the temperature difference between the first temperature and the second temperature is less than a specific value, the limiting amount that limits the charging output is not increased, and if the temperature difference exceeds the specific value, the limiting amount is increased. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a control device that can suppress the temperature rise of the object being cooled while suppressing a decrease in drivability. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a configuration diagram of a vehicle 100 including a control device 7 according to an embodiment of the present disclosure. [Figure 2] Figure 2 shows the time change of water temperature detected by the water temperature sensor 212. [Figure 3A] Figure 3A is a diagram illustrating the general operation of the control device 7. [Figure 3B] Figure 3B is a diagram illustrating the general operation of the control device 7. [Figure 4] Figure 4 is a block diagram showing an example of the hardware configuration of the control device 7. [Figure 5] Figure 5 shows an example of sensor group 200. [Figure 6] Figure 6 is a block diagram showing an example of the functional configuration of the CPU 71A of the control device 7. [Figure 7] Figure 7 is a flowchart illustrating the operation of the control device 7. [Figure 8] Figure 8 is a timing chart illustrating the operation of the control device 7. [Modes for carrying out the invention]

[0009] Hereinafter, one aspect of this disclosure will be described with reference to the drawings. Note that the drawings used in the following description are all schematic, and the dimensional relationships and ratios of the elements shown in the drawings do not necessarily correspond to reality. Furthermore, this disclosure is not limited in any way to the following embodiments, and can be implemented with appropriate modifications within the scope of this disclosure.

[0010] Figure 1 is a diagram showing the configuration of a vehicle 100 including a control device 7 according to an embodiment of the present disclosure. The vehicle 100 is an HEV, and specifically, the vehicle 100 is a series hybrid automobile that uses the internal combustion engine 1 solely for power generation.

[0011] Vehicle 100 includes an internal combustion engine 1, a rotating electric machine 2 which is a motor generator driven by the internal combustion engine 1 to generate electricity, a battery 3 which stores the electricity generated by the rotating electric machine 2, and a rotating electric machine 4 which is a motor generator for driving the drive wheels of vehicle 100, supplied with power from the battery 3. Vehicle 100 also includes a PCU 5, a drivetrain 6, a control device 7, an oil cooler 8, and a cooling system 9.

[0012] The internal combustion engine 1 and the drive wheels are mechanically disconnected. The internal combustion engine 1 can rotate or stop independently of the rotating electric motor 4 and the drive wheels. In a vehicle 100 with the ignition switch (power switch or ignition key) turned ON, if the battery 3 has stored sufficient power, when the driver presses the accelerator pedal, the vehicle 100 can run using the rotating electric motor 4 as the power source without operating the internal combustion engine 1.

[0013] The rotational driving force from the internal combustion engine 1 is input to the rotating electric machine 2, which then generates electricity. The generated electricity is supplied to the battery 3 and the rotating electric machine 4.

[0014] The rotating electric machine 4 is a main motor, a three-phase AC motor, or the like, that generates the driving force for the vehicle's movement. The driving force of the rotating electric machine 4 is input to the drive wheels via the drivetrain 6. The rotating electric machine 4 generates regenerative power by rotating in accordance with the rotation of the drive wheels. The drivetrain 6 may include a power transmission system, tires, etc.

[0015] The PCU5 is equipped with inverters 51 and 52. Inverter 51 converts the AC power generated by the rotating electric machine 2 into DC power and inputs this DC power to the battery 3 and inverter 52. Inverter 52 converts the DC power supplied from the battery 3 and inverter 51 into AC power and inputs this AC power to the rotating electric machine 4. In addition, during regenerative braking of the vehicle, inverter 52 converts the AC power generated by the rotating electric machine 4 into DC power and inputs this DC power to the battery 3.

[0016] The battery 3 is a secondary battery such as a lithium-ion secondary battery or a nickel-metal hydride secondary battery. The battery 3 charges and stores the electric power generated by each of the rotating electrical machines 2 and 4. The battery 3 also supplies the electric power for rotating the rotating electrical machine 4 to the inverter 52.

[0017] The control device 7 is a hybrid ECU (Electronic Control Unit) that generates commands for setting the outputs of the rotating electrical machines 2 and 4. Based on the information from the sensor group mounted on the vehicle 100, the control device 7 generates torque commands, speed commands, position commands, etc. for the rotating electrical machines 2 and 4, thereby controlling the current, voltage, electric power, etc. for driving them.

[0018] For example, based on the detection from the sensor group mounted on the vehicle 100, the control device 7 calculates the target torque of the rotating electrical machine 4 corresponding to the accelerator opening, and generates and outputs a command for controlling the rotating electrical machine 4 with a torque corresponding to the target torque. Based on the temperature detected by the water temperature sensor 212, the control device 7 calculates the charging output of the rotating electrical machine 2, and generates and outputs a command (charging output command) for controlling the rotating electrical machine 2 with a torque corresponding to the charging output. The details of the configuration of the control device 7 will be described later.

[0019] The cooling device 9 is a radiator that cools the rotating electrical machine 2, the rotating electrical machine 4, the PCU 5, etc. by radiating the heat of the cooling water 300 circulating through the cooling device 9, the oil cooler 8, and the PCU 5 into the atmosphere. The oil cooler 8 is a device that cools the oil circulating through, for example, the rotating electrical machine 2, the rotating electrical machine 4, and the transmission mechanism that transmits the rotation of the rotating electrical machine 4 to the drive train 6. When the cooling water 300 passes through the oil cooler 8, heat exchange is performed between the oil flowing through the oil cooler 8 and the cooling water 300.

[0020] The amount of heat exchanged between the cooling device 9 and the coolant 300 increases as the airflow rate passing through the cooling device 9 increases. The airflow rate passing through the cooling device 9 increases as the vehicle 100's speed increases. The airflow rate passing through the cooling device 9 can also be increased by the rotation of the radiator fan 91 connected to the fan motor 92, which is activated by the forced operation of the fan motor 92.

[0021] The fan motor 92 may be controlled by the control device 7 based on the temperature of the cooling water 300, for example, or other functions may be controlled based on the temperature of the cooling water 300. By increasing the amount of heat exchange, for example, the heat generated by at least one of the inverters 51 and 52 included in the PCU 5 can be effectively radiated into the atmosphere, thereby suppressing the temperature rise of the PCU 5. Hereinafter, the temperature of the cooling water 300 may be simply referred to as the water temperature.

[0022] Here, we will explain the changes in water temperature when vehicle 100 is traveling at a low speed up a narrow, steep incline. Figure 2 shows the change in water temperature over time as detected by the water temperature sensor 212. In Figure 2, the vertical axis represents water temperature and the horizontal axis represents time. When vehicle 100 was driven at about 15 km / h on an actual road with a gradient of about 21% (for example, Kuragari Pass), even with the fan motor 92 in the ON state, the water temperature rose by about 3°C ​​every 60 seconds, as shown in Figure 2. In other words, in situations where airflow cannot be expected, the radiator fan 91 alone may not be able to compensate for the heat dissipation, and the water temperature may continue to rise.

[0023] The control device 7 of this disclosure is configured to suppress the increase in losses, i.e., the increase in heat, caused by the operation of the PCU 5, by generating a control command that increases the limit on the charging output by the rotating electric machine 2 for power generation when there is a possibility that the water temperature will continue to rise in a situation in which airflow cannot be expected. Losses caused by the operation of the PCU 5 include, for example, the heat generated by the rotation of the rotating electric machine 2 and the heat generated by the switching operation of IGBTs and other components that make up the inverter 51.

[0024] Figures 3A and 3B are diagrams illustrating the operation overview of the control device 7. Figures 3A and 3B show the work done by the driving rotating electric machine 4 and the work done by the power generating rotating electric machine 2. Figure 3A shows the work done by the rotating electric machine 2 when the control device 7 has not increased the limit on the charging output by the rotating electric machine 2. Figure 3B shows the work done by the rotating electric machine 2 when the control device 7 has increased the limit on the charging output by the rotating electric machine 2.

[0025] The work done by the rotating electric machine 2 includes work A for charging the battery 3, work B for transmission losses from the rotating electric machine 2 to the rotating electric machine 4, and work C for supplying the power required by the rotating electric machine 4 for driving. Work A fluctuates according to the charge state of the battery 3, i.e., the State of Charge (SOC).

[0026] By limiting the charging output, the amount of work A decreases, which reduces the switching operation of IGBTs and other components, and thus reduces the amount of heat generated by the inverter 51. This reduction in the amount of heat generated by the inverter 51 prevents situations where the output of the PCU 5 needs to be limited to protect the PCU 5.

[0027] Furthermore, measures such as adding a dedicated cooler in anticipation of situations where sufficient airflow cannot be expected become unnecessary. This helps to suppress the increase in manufacturing costs of vehicle 100 that would otherwise be incurred by adding a dedicated cooler. In addition, since there is no longer a need to secure space in vehicle 100, PCU5, etc., for the dedicated cooler, it does not hinder the miniaturization of vehicle 100 and PCU5, and thus helps to suppress the increase in manufacturing costs of vehicle 100 and PCU5.

[0028] Furthermore, since there is no need to replace the dedicated cooler with measures such as improving the cooling performance of the cooling device 9, the increase in the manufacturing cost of the cooling device 9 can be suppressed.

[0029] Furthermore, according to the control device 7 of this disclosure, it is possible to suppress the increase in losses occurring in the PCU 5 without using expensive components such as SiC semiconductor switching elements with low switching losses in the inverter 51, for example. Therefore, it is possible to suppress both the decrease in drivability and the temperature rise of the object being cooled while suppressing the increase in the manufacturing cost of the PCU 5.

[0030] Next, an example of the hardware configuration of the control device 7 will be described with reference to Figure 4. Figure 4 is a block diagram showing an example of the hardware configuration of the control device 7. The control device 7 comprises a control unit 71, a communication unit 72, and a storage unit 73.

[0031] The control unit 71 consists of a device including a general-purpose computer. The control unit 71 includes a CPU 71A, ROM 71B, RAM 71C, and an input / output interface (I / O) 71D. The CPU 71A, ROM 71B, RAM 71C, and I / O interface 71D are connected to each other via a bus 71E. The bus 71E includes a control bus, an address bus, and a data bus, etc.

[0032] The input / output interface 71D is connected to the communication unit 72, the memory unit 73, and the sensor group 200. The communication unit 72 is an interface for communicating with external devices such as the PCU 5, brake ECU, and EPS.

[0033] The memory unit 73 is composed of a non-volatile external storage device such as a hard disk. The memory unit 73 stores, for example, a control program 73A.

[0034] CPU71A is an example of a computer. Here, "computer" refers to a processor in a broad sense, and may include general-purpose processors or specialized processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0035] The control program 73A may be stored in the storage unit 73 by being stored on a non-volatile, non-transitory recording medium or distributed via a network and installed appropriately on the control device 7. Furthermore, the control program 73A may be updated as appropriate via so-called OTA (Over The Air).

[0036] Examples of non-volatile, non-transitional recording media include CD-ROMs (Compact Disc Read Only Memory), magneto-optical disks, HDDs (Hard Disk Drives), DVD-ROMs (Digital Versatile Disc Read Only Memory), flash memory, and memory cards.

[0037] Vehicle 100 may be equipped with numerous sensors for measuring various physical quantities. Figure 5 is a block diagram showing an example of a sensor group 200. The sensor group 200 includes a wheel speed sensor 201, an acceleration sensor 202, a current sensor 203, an external camera 204, an accelerator sensor 205, an external temperature sensor 206, and a gradient sensor 207. The sensor group 200 may also include a brake sensor 208, a parking sensor 209, a yaw rate sensor 210, a rotation speed sensor 211, and a water temperature sensor 212.

[0038] The wheel speed sensor 201 is a sensor for measuring the number of rotations of the wheel per unit time. The acceleration sensor 202 is a sensor for detecting the acceleration of the vehicle 100. The current sensor 203 is a sensor for detecting the value of the current flowing through the rotating electric machine 4. The signal indicating the value of the drive current detected by the current sensor 203 is input to the control device 7. Based on the input value of the drive current, the control device 7 can determine the magnitude of the driving force generated by the rotating electric machine 4.

[0039] The external camera 204 is a camera that photographs the area around the vehicle 100, and is, for example, a CMOS (Complementary Metal Oxide Semiconductor) camera. The accelerator sensor 205 is a sensor that detects the amount of accelerator pedal operation, i.e., the accelerator opening angle. The signal indicating the amount of accelerator pedal operation detected by the accelerator sensor 205 is input to the control device 7.

[0040] The external temperature sensor 206 is a sensor that detects the external temperature of the vehicle 100. The gradient sensor 207 is a sensor that detects the gradient of the road surface on which the vehicle 100 is traveling. The brake sensor 208 is a sensor that detects the brake hydraulic pressure of the brake system. The parking sensor 209 is a sensor that detects whether the parking brake of the vehicle 100 is on or off. The yaw rate sensor 210 is a sensor for detecting the yaw rate of the vehicle 100. The rotation speed sensor 211 is a sensor for detecting the rotation angle and rotation speed of the rotating electric machine 4.

[0041] The water temperature sensor 212 is a sensor that detects the temperature of the cooling water 300 circulating between the PCU 5 and the cooling device 9. The water temperature sensor 212 is installed, for example, near the inlet where the cooling water 300 is introduced into the PCU 5.

[0042] The location of the water temperature sensor 212 is not limited to this. The water temperature sensor 212 may be located near the outlet where the coolant 300 is discharged from the PCU 5, or near the inlet where the coolant 300 is introduced into the oil cooler 8. Alternatively, the water temperature sensor 212 may be located near the inlet where the coolant 300 heated by the oil cooler 8 is introduced into the cooling system 9.

[0043] The control device 7 can manage the temperature change of the PCU 5 by changing the criteria, or control reference point, depending on the installation position of the water temperature sensor 212.

[0044] Next, an example of the functional configuration of the CPU 71A of the control device 7 will be described with reference to Figure 6. Figure 6 is a block diagram showing an example of the functional configuration of the CPU 71A of the control device 7. Here, we will describe the function for controlling the inverter 51, which controls the rotation of the rotating electric machine 2 for power generation, which is a feature of the present invention.

[0045] The CPU 71A functions as one of the functional units shown in Figure 6 by reading and executing the control program 73A stored in the memory unit 73 (see Figure 4). The CPU 71A includes an information input unit 711 and a control unit 712, among others.

[0046] (Information input section 711) The information input unit 711 receives information detected by the sensor group 200.

[0047] (Control Unit 712) The control unit 712 monitors the water temperature input to the information input unit 711 at specific intervals and retains the monitored water temperature. The control unit 712 continues to retain the monitored water temperature in chronological order at specific intervals. For example, if the monitored water temperature is on an upward trend, the control unit 712 retains a specific water temperature (e.g., 57°C) detected at a specific first time point, and retains the water temperature (e.g., 58°C) detected at a second time point 30 seconds after the first time point. Furthermore, the control unit 712 retains the water temperature (e.g., 58.5°C) detected at a third time point 30 seconds after the second time point, retains the water temperature (e.g., 60°C) detected at a fourth time point 30 seconds after the third time point, and retains the water temperature (e.g., 61.5°C) detected at a fifth time point 30 seconds after the fourth time point. Furthermore, if the monitored water temperature changes from an upward trend to a downward trend, for example, the control unit 712 retains the water temperature detected at the 6th time (e.g., 60°C) 30 seconds after a specific 5th time, retains the water temperature detected at the 7th time (e.g., 58.5°C) 30 seconds after the 6th time, and retains the water temperature detected at the 8th time (e.g., 58°C) 30 seconds after the 7th time. The specific interval can be interpreted as the detection time for monitoring (detecting) the water temperature, and is, for example, 30 seconds, but may also be a time other than 30 seconds, such as 15 seconds, 25 seconds, 35 seconds, etc.

[0048] (Normal charging control) The control unit 712 performs normal charging control when, for example, the water temperature detected near the inlet where the cooling water 300 is introduced into the PCU 5, i.e., near the inlet of the PCU 5, is below a certain threshold T2 (e.g., 58°C). Normal charging control is a control that changes the amount of charge according to the State of Charge (SOC) of the battery 3 without changing the aforementioned limit on the charging output according to the water temperature, that is, without limiting the charging output.

[0049] For example, if the estimated SOC value based on the voltage of battery 3 tends to be low (for example, around SOC = 40%), the control unit 712 determines that charging of battery 3 is necessary and controls the inverter 51 to generate a constant charging output until the SOC reaches a specific value. Then, when the SOC reaches the specific value, the control unit 712 controls the inverter 51 to stop the charging output.

[0050] (Control to limit charging output, control to stop charging output) For example, if the water temperature detected near the inlet where the cooling water 300 is introduced into the PCU 5 exceeds a specific threshold T2 (e.g., 58°C), the control unit 712 executes control to limit the charging output or executes control to stop the charging output.

[0051] Specifically, the control unit 712 performs control to limit the charging output in stages or continuously, that is, control to suppress the charging output (charging output limiting control), when the water temperature exceeds a specific threshold T2 (e.g., 58°C) and is less than or equal to a threshold T1 (e.g., 65°C) that is higher than threshold T2.

[0052] On the other hand, the control unit 712 controls the charging to stop (stop charging output control) if the water temperature exceeds a threshold T1 (e.g., 65°C), that is, it sets the limit of the charging output to 100%. At this time, the control unit 712 may also stop charging on the condition that the SOC is above the minimum value necessary that does not affect driving (e.g., 40%).

[0053] The following describes in detail the charging output limit control, which is a feature of this disclosure. The control unit 712 compares a first temperature (the most recent water temperature) with a second temperature (the previous water temperature) that was immediately preceding the first temperature, from among a plurality of water temperatures held in chronological order. If the temperature difference between the first temperature and the second temperature is less than a certain value, the limit amount for limiting the charging output is not increased. If the temperature difference exceeds the certain value, the limit amount for limiting the charging output is increased. In determining whether the temperature difference is less than a certain value, in order to suppress hunting of the charging output limit control, for example, it is determined whether the temperature difference between the most recent water temperature and the previous water temperature is greater than or less than a certain value (e.g., 1.0°C).

[0054] (Example of a judgment when water temperature is on an upward trend) For example, if the water temperature at the second time point (e.g., 58°C) and the water temperature at the third time point (e.g., 58.5°C), 30 seconds after the second time point, are compared and the temperature difference is +0.5°C, the control unit 712 determines that the temperature difference of the rising water temperature does not exceed a specific value (e.g., +1.0°C).

[0055] Furthermore, for example, if the water temperature at the third time point (e.g., 58.5°C) and the water temperature at the fourth time point (e.g., 60°C), 30 seconds after the third time point, are compared and the temperature difference is +1.5°C, the control unit 712 determines that the temperature difference of the rising water temperature exceeds a specific value (e.g., +1.0°C) and increments the emergency counter cumulative value by one. The emergency counter cumulative value is a value used to set a limit on the charging output by the rotating electric machine 2 in situations where the rising water temperature may cause insufficient cooling of the PCU 5. When the emergency counter cumulative value is incremented by one, the control unit 712 increases the control amount of the charging output by, for example, 10%.

[0056] Furthermore, for example, if the water temperature at the fourth time point (e.g., 60°C) and the water temperature at the fifth time point (e.g., 61.5°C), 30 seconds after the fourth time point, are compared and the temperature difference is +1.5°C, the control unit 712 will determine that the temperature difference of the water temperature, which is still on an upward trend, exceeds a certain value (e.g., 1.0°C). In this case, the control unit 712 will increment the emergency counter cumulative value by another unit and further increase the charge output control amount by, for example, 10%. In other words, the charge output control amount is increased by a percentage corresponding to the number of previously accumulated emergency counter values.

[0057] Thus, the control unit 712 does not increase the limit on the charging output if the temperature difference between the latest water temperature (which is on an upward trend) and the previous water temperature is less than a certain value, but increases the limit on the charging output if the temperature difference exceeds a certain value. By increasing the limit on the charging output, it is possible to charge the battery 3 while slowing down the rise in water temperature.

[0058] (Example of a judgment when water temperature rises and then changes to a downward trend) When the incline of the uphill slope becomes gentler and the vehicle width increases, creating conditions that allow for greater airflow, the water temperature, which had been on an upward trend, may begin to decline. For example, if comparing the water temperature at the fifth time (61.5°C) mentioned above with the water temperature at the sixth time (e.g., 60°C) 30 seconds after the fifth time, and the water temperature has changed from rising to falling, resulting in a temperature difference of -1.5°C, the control unit 712 determines that the temperature difference of the declining water temperature exceeds a certain value (e.g., -1.0°C), meaning it is below -1.0°C. In this case, the control unit 712 decrements the emergency counter cumulative value by one and reduces the charge output control amount by, for example, 10%.

[0059] Furthermore, for example, if the water temperature at the sixth time (e.g., 60°C) and the water temperature at the seventh time (e.g., 58.5°C), 30 seconds after the sixth time, are compared and the temperature difference is -1.5°C, the control unit 712 will determine that the temperature difference of the water temperature, which is still trending downwards, exceeds a certain value (e.g., 1.0°C), that is, it is below -1.0°C. In this case, the control unit 712 further decrements the emergency counter cumulative value by one and further reduces the charge output control amount by, for example, 10%. In other words, the charge output control amount is reduced by a percentage corresponding to the number of the previous emergency counter cumulative values.

[0060] Thus, the control unit 712 does not reduce the charging output limit when the temperature difference between the latest water temperature (which is on a downward trend) and the previous water temperature is less than a certain value, but reduces the charging output limit when the temperature difference exceeds that certain value. By reducing the charging output limit, it is possible to increase the amount of charge to the battery 3 while suppressing the rise in water temperature.

[0061] (Another configuration example of the control unit 712 1) The control unit 712 may perform control to increase the limit amount of the charging output if the temperature difference between the latest water temperature and the previous water temperature exceeds a certain value while the fan (radiator fan 91) that blows air to the cooling device 9 is running.

[0062] For example, if the radiator fan 91 is not activated because there is no need to suppress the rise in water temperature, the control unit 712 may not perform the charging output limit control. The control unit 712 then starts the charging output limit control when the water temperature exceeds a specific threshold T2 (e.g., 58°C) and the fan motor 92 is activated to suppress the rise in water temperature. If the water temperature falls below the specific threshold T2 (e.g., 58°C) while the charging output limit control is being performed, the control unit 712 stops the fan motor 92 and switches to normal charging control.

[0063] With this configuration, the charging output is limited when the radiator fan 91 is activated after the water temperature exceeds a certain threshold T2 (e.g., 58°C). This increases the amount of heat exchange between the cooling device 9 and the coolant 300, effectively suppressing the rise in water temperature. Consequently, the temperature rise of the PCU 5 can be further suppressed. In addition, because the water temperature can decrease more quickly, the timing of the transition to normal charging control is accelerated, and the power required to drive the vehicle 100 can be increased.

[0064] Furthermore, the timing of the radiator fan 91's activation is not limited to when the water temperature exceeds a specific threshold; it may also occur after a specific time has elapsed since the start of the charging output limit control, or even before a specific time has elapsed since the start of the charging output limit control.

[0065] For example, if the water temperature rises slowly, the water temperature rise can be suppressed by limiting the charging output even if the radiator fan 91 is started later, thus reducing the power consumption required to drive the fan motor 92. If the water temperature rises quickly, the water temperature rise can be effectively suppressed by starting the radiator fan 91 earlier. As the water temperature rise is suppressed, the timing of the transition to normal charging control is accelerated, and the power required to drive the vehicle 100 can be increased.

[0066] (Another configuration example of the control unit 712 2) As described above, the control unit 712 increases the limit on the charging output by a specific percentage (e.g., 10%) each time the water temperature rises at the specified intervals mentioned above. Conversely, the control unit 712 decreases the limit on the charging output by a specific percentage (e.g., 10%) each time the water temperature falls at the specified intervals mentioned above. In other words, the control unit 712 increases or decreases the limit on the charging output by a fixed percentage, such as 10%, regardless of the degree of rise or fall in water temperature.

[0067] For example, if the water temperature at the third time point is 58.5°C, and the water temperature at the fourth time point (30 seconds after the third time point) is 60°C, the temperature difference is +1.5°C. In this case, the control unit 712 determines that the temperature difference of the rising water temperature exceeds a specific value (e.g., +1.0°C) and increments the emergency counter cumulative value by one. In this case, the charging output limit increases by a specific percentage (e.g., 10%). On the other hand, even if the water temperature at the fifth time point (30 seconds after the fourth time point) rises to, for example, 63.0°C, and the temperature difference between the water temperature at the fourth time point and the water temperature at the fifth time point (3°C) exceeds the specific value of +1.0°C, the control unit 712 increments the emergency counter cumulative value by one and further increases the charging output limit by a specific percentage (e.g., 10%). In other words, the charging output limit is increased by a constant percentage regardless of the magnitude of the water temperature difference.

[0068] Similarly, when the water temperature is on a downward trend, the control unit 712 reduces the limit on the charging output by a certain percentage, regardless of the magnitude of the temperature difference in the water temperature. For example, when the temperature difference in the water temperature is -1.0°C, the control unit 712 reduces the limit on the charging output by a specific percentage (e.g., 10%), and when the temperature difference in the water temperature is -2.0°C, it also reduces the limit on the charging output by a specific percentage (e.g., 10%).

[0069] In this way, by increasing or decreasing the limit amount of the charging output by a specific percentage, sudden changes in the limit amount can be suppressed, thereby suppressing rapid rotational fluctuations of the rotating electric machine 2 for power generation and alleviating anxiety for the driver. Furthermore, by increasing or decreasing the limit amount of the charging output by a specific percentage, the charging output can be easily changed without setting specific table information (for example, information that associates multiple water temperatures with different values ​​with the corresponding control amount of the charging output for each of these water temperatures). Therefore, the control algorithm of the control unit 712 can be simplified.

[0070] Furthermore, the percentage by which the charging output limit is increased or decreased is not limited to 10%; for example, 15%, 12%, 5%, 3%, etc., are also acceptable.

[0071] Next, the operation of the control device 7 will be explained with reference to Figures 7 and 8. Figure 7 is a flowchart illustrating the operation of the control device 7. Figure 8 is a timing chart illustrating the operation of the control device 7.

[0072] The process shown in Figure 7 is initiated, for example, when a charge request is input to the control unit 712. In step S1, the control unit 712 compares the latest water temperature with a threshold T1 (e.g., 65°C) to determine whether the water temperature exceeds the threshold T1.

[0073] If the water temperature exceeds the threshold T1, the control unit 712 stops the charging control by executing the process in step S2. In the process in step S2, the charging control is stopped after ensuring a minimum SOC that does not affect driving.

[0074] If the water temperature is below the threshold T1, the control unit 712 executes the process in step S3. In step S3, the control unit 712 determines whether the water temperature is above the threshold T2 (for example, 58°C). If the water temperature is above the threshold T2, the control unit 712 executes the process in step S4.

[0075] At this time, the control unit 712 may start the fan motor 92 to suppress the rise in water temperature (see time t1 in Figure 8). Alternatively, at time t2, a certain period of time after time t1 in Figure 8, the control unit 712 may activate the emergency determination logic, that is, determine that an emergency has occurred and set a confirmation flag. Activating the emergency determination logic involves adding or subtracting the accumulated value of the emergency counter.

[0076] In step S4, the control unit 712 starts counting up a timer for detecting changes in water temperature, for example, from the time the water temperature is detected at a specific time. The control unit 712 continues counting up the timer until a specific interval (e.g., 30 seconds) has elapsed, and when the timer count reaches 30 seconds, it executes the process of step S5.

[0077] In step S5, the control unit 712 compares the latest water temperature with the previous water temperature to determine whether the water temperature is trending upward or downward. If the temperature (water temperature) is trending upward, the control unit 712 executes the process in step S6.

[0078] In step S6, the control unit 712 determines whether the temperature difference between the latest water temperature and the previous water temperature exceeds a specific value (for example, +1.0°C), that is, whether the latest water temperature has increased by 1°C or more compared to the previous water temperature. If the latest water temperature has increased by 1°C or more compared to the previous water temperature, the control unit 712 executes the process in step S7. If the latest water temperature has not increased by 1°C or more compared to the previous water temperature, the control unit 712 executes the process in step S5 again.

[0079] In step S7, the control unit 712 accumulates one emergency counter value, and in step S8, outputs a charge output command value that reduces the charge output by 10%, that is, increases the charge output limit by 10% compared to the previous value (see time t3 in Figure 8). After that, the control unit 712 repeatedly executes the processes from step S1 onward.

[0080] By executing the processes from step S1 onward, if the latest water temperature increases further than the previous water temperature, the charging output limit is increased by another 10% at time t5, as shown in Figure 8. Subsequently, if the latest water temperature increases further, a charging output command value is output at time t6 in Figure 8 that further increases the charging output limit by another 10%.

[0081] Returning to step S5, if the temperature (water temperature) is trending downwards, the control unit 712 executes the process in step S9.

[0082] In step S9, the control unit 712 determines whether the temperature difference between the current water temperature, which is on a downward trend, and the previous water temperature exceeds a specific value (for example, -1.0°C), that is, whether the current water temperature has decreased by 1°C or more compared to the previous water temperature. If the current water temperature has decreased by 1°C or more compared to the previous water temperature, the control unit 712 executes step S10. If the current water temperature has not decreased by 1°C or more compared to the previous water temperature, the control unit 712 repeatedly executes the process from step S1 onwards.

[0083] If the latest water temperature is 1°C or more lower than the previous water temperature, the control unit 712 determines in step S10 whether the accumulated value of the emergency counter is 1 or more. If the accumulated value of the emergency counter is 1 or more, the control unit 712 executes the process in step S11. If the accumulated value of the emergency counter is not 1 or more, that is, if the accumulated value of the emergency counter is 0, the control unit 712 repeatedly executes the processes from step S1 onward.

[0084] In step S11, the control unit 712 decrements the accumulated value of the emergency counter by one, and in step S12, increases the charging output by 10%, that is, reduces the limit of the charging output by 10% compared to the previous value (see time t7 in Figure 8). After that, the control unit 712 repeatedly executes the processes from step S1 onward.

[0085] By executing the processes from step S1 onward, if the latest water temperature decreases further than the previous water temperature, the charging output limit is further reduced by 10% at time t8, as shown in Figure 8, and then, if the latest water temperature decreases further, a charging output command value is output at time t9 that further reduces the charging output limit by 10%.

[0086] Returning to step S3, if the water temperature is below the threshold T2, the PCU5 is not in a high-temperature state, and therefore the control unit 712 executes the processing from step S13 onward.

[0087] In step S13, the control unit 712 determines whether the accumulated value of the emergency counter is 1 or greater.

[0088] If the accumulated value of the emergency counter is 1 or more, the control unit 712 switches to normal charging control without limiting the charging output in step S14. At this time, in order to avoid abrupt changes in the amount of the charging output limit, a rate limit may be applied to the output limit.

[0089] Subsequently, in step S15, the control unit 712 resets the emergency counter cumulative value, and in step S16, it performs normal charging control.

[0090] Returning to step S13, if the accumulated value of the emergency counter is less than 1, i.e., 0, steps S15 and S16 are executed without going through the process in step S14.

[0091] As described above, the control device 7 of this disclosure maintains the water temperature in a time series at specific intervals, and compares the most recent maintained temperature with the previous temperature. If the temperature difference between the most recent temperature, which is showing an upward trend, and the previous temperature is less than a specific value, the limit amount for limiting the charging output is not increased. If the temperature difference exceeds a specific value, the limit amount for limiting the charging output is increased.

[0092] This configuration allows for an increase in the State of Charge (SOC) of battery 3 by not limiting the charging output when the coolant temperature 300 is below a certain threshold, thereby providing the power necessary to run vehicle 100. Furthermore, if the coolant temperature 300 is on the rise and the temperature difference exceeds a certain threshold, the charging output is limited, suppressing the increase in losses caused by the operation of PCU 5. As a result, the SOC of battery 3 can be maintained while suppressing the decrease in drivability caused by the temperature rise of PCU 5.

[0093] The control program 73A of this disclosure may be installed in an information processing device such as a server that includes at least one processor. In this case, the server receives information detected by the sensor group 200, monitors the water temperature at specific intervals based on the received information and the control program 73A, maintains the monitored water temperature, and compares the first water temperature with the second water temperature immediately preceding the first water temperature among the multiple water temperatures maintained. If the temperature difference between the first water temperature, which is on an upward trend, and the second water temperature is less than a specific value, the server does not increase the limit amount that restricts the charging output. If the temperature difference exceeds the specific value, the server performs specific control to increase the limit amount that restricts the charging output and transmits the control command to the control device 7 of the vehicle 100. In addition, in the specific control, the server may increase the limit amount that restricts the charging output if the temperature difference exceeds a specific value while the fan that blows air to the cooling device 9 is running. In addition, in the specific control, the server may increase the limit amount that restricts the charging output by a specific percentage each time the water temperature rises at the aforementioned specific intervals.

[0094] The following additional information is disclosed regarding the above-described embodiments.

[0095] (Note 1) It includes a control unit that controls the charging output of a generator that generates power to charge the battery installed in the vehicle, The control unit, The temperature detected by a water temperature sensor, which detects the temperature of the cooling water circulating between the inverter that drives the rotating electric machine for the vehicle's propulsion and the cooling device that cools the inverter, is monitored at specific intervals. Maintain the monitored temperature, Of the multiple temperatures held, the first temperature is compared with the second temperature immediately preceding the first temperature. A control device that, as a result of the comparison, if the temperature difference between the first temperature and the second temperature, which is on an upward trend, is less than a certain value, does not increase the limit amount that limits the charging output, and increases the limit amount if the temperature difference exceeds the certain value.

[0096] (Note 2) The control unit, as described in Appendix 1, controls the limit amount to increase the limit amount when the temperature difference exceeds a specific value while the fan supplying air to the cooling device is running.

[0097] (Note 3) The control device according to Appendix 1, wherein the control unit increases the limit amount by a specific percentage each time the temperature rises at a specific interval.

[0098] (Note 4) At least one processor, It controls the charging output of the generator that generates power to charge the battery installed in the vehicle. The temperature detected by a water temperature sensor, which detects the temperature of the cooling water circulating between the inverter that drives the rotating electric machine for the vehicle's propulsion and the cooling device that cools the inverter, is monitored at specific intervals. Maintain the monitored temperature, Of the multiple temperatures held, the first temperature is compared with the second temperature immediately preceding the first temperature. As a result of the comparison, if the temperature difference between the first temperature and the second temperature, which are on an upward trend, is less than a certain value, the limiting amount for limiting the charging output will not be increased; however, if the temperature difference exceeds the certain value, the limiting amount will be increased. A control program that executes a process that includes the following.

[0099] (Note 5) At least one processor, It controls the charging output of the generator that generates power to charge the battery installed in the vehicle. The temperature detected by a water temperature sensor, which detects the temperature of the cooling water circulating between the inverter that drives the rotating electric machine for the vehicle's propulsion and the cooling device that cools the inverter, is monitored at specific intervals. Maintain the monitored temperature, Of the multiple temperatures held, the first temperature is compared with the second temperature immediately preceding the first temperature. As a result of the comparison, if the temperature difference between the first temperature and the second temperature, which are on an upward trend, is less than a certain value, the limiting amount for limiting the charging output will not be increased; however, if the temperature difference exceeds the certain value, the limiting amount will be increased. A control method for executing a process that includes the following.

[0100] The control unit and method described herein may be implemented by a dedicated computer comprising a processor programmed to perform one or more functions embodied by a computer program. Alternatively, the apparatus and method described herein may be implemented by a dedicated computer comprising a processor composed of dedicated hardware logic circuits. Alternatively, the apparatus and method described herein may be implemented by one or more dedicated computers comprising a combination of a processor that executes a computer program and one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by the computer on a computer-readable non-transitional tangible recording medium. [Explanation of Symbols]

[0101] 1. Internal combustion engine 2 Rotating Electric Machines 3 Batteries 4 Rotating Electric Machines 5 PCU 6 Drivetrain 7 Control device 8. Oil cooler 9 Cooling device 51 Inverter 52 Inverters 71 Control Unit 71A CPU 71B ROM 71C RAM 71D Input / Output Interface 71E Bus 72 Communications Department 73 Memory section 73A Control Program 91 Radiator fan 92 Fan motor 100 vehicles 200 sensor group 201 Wheel speed sensor 202 Accelerometer 203 Current Sensor 204 Exterior car camera 205 Accelerator Sensor 206 External temperature sensor 207 Gradient Sensor 208 Brake Sensor 209 Parking Sensor 210 Yaw Rate Sensor 211 Rotation speed sensor 212 Water temperature sensor 300 Cooling water 711 Information Input Section 712 Control Unit

Claims

1. It includes a control unit that controls the charging output of a generator that generates power to charge the battery installed in the vehicle, The control unit, The temperature detected by a water temperature sensor, which detects the temperature of the cooling water circulating between the inverter that drives the rotating electric machine for the vehicle's propulsion and the cooling device that cools the inverter, is monitored at specific intervals. Maintain the monitored temperature, Of the multiple temperatures held, the first temperature is compared with the second temperature immediately preceding the first temperature. A control device that, as a result of the comparison, if the temperature difference between the first temperature and the second temperature, which is on an upward trend, is less than a certain value, does not increase the limit amount that limits the charging output, and increases the limit amount if the temperature difference exceeds the certain value.

2. The control device according to claim 1, wherein the control unit controls the limit amount to increase the limit amount when the temperature difference exceeds a specific value while the fan that blows air to the cooling device is running.

3. The control device according to claim 1, wherein the control unit increases the limit amount by a specific percentage each time the temperature rises at a specific interval.

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