Control method, control device and storage medium

Abstract

The invention provides a control method, a control device, and a storage medium for appropriately deriving a saturation temperature of a power conversion device and a loss at the time of the saturation temperature. The control device is provided with: a loss characteristic derivation unit that derives, on the basis of the operating condition of the first motor generator, a loss characteristic indicating the loss of the power conversion device at each temperature; a thermal resistance derivation unit that derives a thermal resistance of the power conversion device on the basis of a cooling condition of the cooling device; a thermal resistance characteristic deriving unit that derives a thermal resistance characteristic of the power conversion device on the basis of the loss characteristic and the thermal resistance; a saturation temperature / loss derivation unit at saturation temperature deriving the saturation temperature of the power conversion device and the loss at saturation temperature on the basis of the loss characteristic and the thermal resistance characteristic; and a vehicle control unit that controls the vehicle on the basis of the saturation temperature and the loss at the saturation temperature.

Description

Technical Field

[0001] This invention relates to a control method, a control device, and a storage medium. Background Technology

[0002] In recent years, initiatives aimed at achieving a low-carbon or decarbonized society have been very active as a concrete countermeasure to address global climate change. In mobile vehicles such as automobiles, there are also requirements for reducing CO2 emissions and improving energy efficiency, leading to ongoing research and development of electrification technologies to power their drive sources.

[0003] Patent document 1 discloses the following technique: calculating the power loss at each motor temperature when driving the motor at the predicted operating point, the operating speed of the fan and pump at each motor temperature, and the power consumption of the fan and pump when operating at the operating speed, then calculating the sum of the motor power loss, fan power consumption, and pump power consumption for each motor temperature, and setting the motor temperature with the smallest sum as the target motor temperature.

[0004] In addition, Patent Document 2 discloses the following technology: calculating the possible losses in the inverter based on the motor's required output, and controlling the pump's discharge rate and the fan's cooling air supply rate based on the calculation result.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 5417123

[0008] Patent Document 2: Japanese Patent No. 5258079 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] However, in the aforementioned prior art, the techniques for deriving the saturation temperature and the loss at the saturation temperature have not been sufficiently studied, and therefore there is room for improvement in this regard. The saturation temperature is the temperature reached by the power conversion device when the electric generator is operated under specified operating conditions and the power conversion device that receives and supplies power to the electric generator is cooled under specified cooling conditions, and the loss at the saturation temperature is the loss of the power conversion device at the saturation temperature.

[0011] This invention provides a control method, control device, and control program capable of appropriately deriving the saturation temperature and losses at saturation temperature of a power conversion device. Furthermore, this contributes to improved energy efficiency.

[0012] Methods for solving problems

[0013] One aspect of the present invention relates to a control method executed by a computer controlling a mobile body, the mobile body comprising: an electric generator; a power conversion device that receives and exchanges power with the electric generator; and a cooling device that cools the power conversion device, wherein...

[0014] The computer performs the following processing:

[0015] Based on the operating conditions of the electric generator, loss characteristics are derived, which represent the losses of the power conversion device at each temperature when the electric generator is operating under these conditions.

[0016] Based on the cooling conditions of the cooling device for cooling the power conversion device, the thermal resistance of the power conversion device under these cooling conditions is derived.

[0017] Based on the aforementioned loss characteristics and thermal resistance, a thermal resistance characteristic is derived, which represents the temperature at which each loss of the power conversion device reaches its destination.

[0018] Based on the aforementioned loss characteristics and thermal resistance characteristics, the saturation temperature and the loss at saturation temperature are derived. The saturation temperature is the temperature reached by the power conversion device when the electric generator is operating under the aforementioned operating conditions and the power conversion device is cooled under the aforementioned cooling conditions. The loss at saturation temperature is the loss of the power conversion device at that saturation temperature.

[0019] The moving body is controlled based on the saturation temperature and / or the loss at the saturation temperature.

[0020] Another aspect of the invention relates to a control device that controls a moving body, the moving body comprising: an electric generator; a power conversion device that receives and exchanges power with the electric generator; and a cooling device that cools the power conversion device, wherein...

[0021] The control device includes:

[0022] The loss characteristic derivation section derives loss characteristics based on the operating conditions of the electric generator, which represent the losses of the power conversion device at each temperature when the electric generator is operating under those operating conditions.

[0023] The thermal resistance output section outputs the thermal resistance of the power conversion device under the cooling conditions of the cooling device cooling the power conversion device.

[0024] A thermal resistance characteristic derivation section derives a thermal resistance characteristic based on the loss characteristic derived by the loss characteristic derivation section and the thermal resistance derived by the thermal resistance derivation section, the thermal resistance characteristic representing the arrival temperature of each loss of the power conversion device.

[0025] A loss derivation section at saturation temperature / saturation temperature, based on the loss characteristics and the thermal resistance characteristics derived by the thermal resistance characteristic derivation section, derives the saturation temperature and the loss at saturation temperature, where the saturation temperature is the temperature reached by the power conversion device when the electric generator is operated under the stated operating conditions and the power conversion device is cooled under the stated cooling conditions, and the loss at saturation temperature is the loss of the power conversion device when it reaches that saturation temperature; and

[0026] The moving body control unit controls the moving body based on the saturation temperature and / or the loss at the saturation temperature derived by the loss derivation unit at the saturation temperature / saturation temperature.

[0027] Another aspect of the invention relates to a control program that causes a computer controlling a mobile body to perform predetermined processing, the mobile body comprising: an electric generator; a power conversion device that receives and exchanges power with the electric generator; and a cooling device that cools the power conversion device, wherein...

[0028] The control program causes the computer to perform the following processes:

[0029] Based on the operating conditions of the electric generator, loss characteristics are derived, which represent the losses of the power conversion device at each temperature when the electric generator is operating under these conditions.

[0030] Based on the cooling conditions of the cooling device for cooling the power conversion device, the thermal resistance of the power conversion device under these cooling conditions is derived.

[0031] Based on the aforementioned loss characteristics and thermal resistance, a thermal resistance characteristic is derived, which represents the temperature at which each loss of the power conversion device reaches its destination.

[0032] Based on the aforementioned loss characteristics and thermal resistance characteristics, the saturation temperature and the loss at saturation temperature are derived. The saturation temperature is the temperature reached by the power conversion device when the electric generator is operating under the aforementioned operating conditions and the power conversion device is cooled under the aforementioned cooling conditions. The loss at saturation temperature is the loss of the power conversion device at that saturation temperature.

[0033] The moving body is controlled based on the saturation temperature and / or the loss at the saturation temperature.

[0034] Invention Effects

[0035] According to the present invention, a control method, control device, and control program are provided that can appropriately derive the saturation temperature of a power conversion device and the losses at the saturation temperature. Attached Figure Description

[0036] Figure 1 This is a diagram showing an example of the schematic structure of vehicle 1 according to this embodiment.

[0037] Figure 2 This is a block diagram illustrating an example of the functional structure of the control device 50.

[0038] Figure 3 This is a flowchart illustrating an example of a process performed by the control device 50.

[0039] Figure 4 This is a diagram illustrating an example of the method for deriving the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature in the first utilization example.

[0040] Figure 5 This is a diagram illustrating an example of the method for deriving the loss PlsTsat2 at the second saturation temperature and the second saturation temperature in the first utilization example.

[0041] Figure 6 This is a diagram illustrating an example of the method for deriving the third saturation temperature Tsat3 and the loss PlsTsat3 at the third saturation temperature in the first utilization example.

[0042] Figure 7 This is a diagram illustrating an example of how to find the optimal duty cycle in the first utilization example.

[0043] Figure 8 This is a diagram illustrating an example of the method for deriving the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature in the second utilization example.

[0044] Figure 9 This is a diagram illustrating an example of a method for finding the optimal V2 voltage in the second application example.

[0045] Figure 10 This is a diagram illustrating an example of an anomaly detection method for the device temperature sensor 36 in the third application example.

[0046] Figure 11 This is a diagram illustrating an example of a judgment made by the control device 50 in a modified example of the third utilization example, corresponding to the temperature state of each device.

[0047] Figure 12 This is a diagram illustrating an example of an anomaly detection method for a water temperature sensor in a modified example of the third utilization example.

[0048] Figure 13 This is a diagram illustrating an example of the vehicle control method in the fourth application example.

[0049] Explanation of reference numerals in the attached figures

[0050] 1. Vehicle (mobile vehicle)

[0051] 10 Power conversion devices

[0052] 11. First Inverter (Power Conversion Device)

[0053] 12 Second Inverter (Power Conversion Device)

[0054] 13. Voltage conversion device (power conversion device)

[0055] 20 Cooling devices

[0056] 21 Cooling Circuit

[0057] 22 Electric Pump

[0058] 35 Water Temperature Sensor

[0059] 36 Equipment Temperature Sensors

[0060] 36a First Equipment Temperature Sensor

[0061] 36b Second Equipment Temperature Sensor

[0062] 36c Third Device Temperature Sensor

[0063] 50 control devices

[0064] 51 Loss Characteristic Derivation Section

[0065] 52 Traffic Export Department

[0066] 53 Thermal resistance output section

[0067] 54 Thermal Resistance Characteristic Derivation Section

[0068] 55% saturation temperature / Loss at saturation temperature

[0069] 56. Vehicle Control Department (Moving Body Control Department)

[0070] CP intersection

[0071] Lc loss characteristics

[0072] Loss at PlsTsat saturation temperature

[0073] Rc thermal resistance characteristics

[0074] Tsat saturation temperature Detailed Implementation

[0075] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, the following embodiment is an example in which the moving body of the present invention is a vehicle. Additionally, hereafter, the same or similar elements will be labeled with the same or similar reference numerals, and their descriptions may sometimes be omitted or simplified as appropriate.

[0076] [1. General structure of the vehicle]

[0077] Figure 1 This is a diagram illustrating an example of the schematic structure of vehicle 1 according to this embodiment. (See diagram for example.) Figure 1 The vehicle 1 shown in this embodiment is a hybrid electric vehicle, which is configured to include a battery BAT, an engine ENG, a first electric generator MG1, a second electric generator MG2, a power conversion device 10, a cooling device 20, a vehicle sensor 30, and a control device 50.

[0078] A battery AT (Battery Actuator) is a rechargeable battery. For example, a battery AT consists of multiple individual batteries connected in series or parallel, configured to output a high voltage of 100V to 400V. The individual batteries used in a battery AT can be, for example, lithium-ion batteries or nickel-metal hydride batteries.

[0079] The engine ENG is, for example, an internal combustion engine that outputs power by burning a fuel such as gasoline, light oil, or a mixture of ethanol. The engine ENG is mechanically connected to the second electric generator MG2 (described later) and can also be mechanically connected to the drive wheel DW of the vehicle 1 via a clutch CL. The clutch CL can be, for example, a friction clutch. When the clutch CL is engaged (i.e., in the connected state), the power output from the engine ENG is transmitted to the second electric generator MG2 and the drive wheel DW; when the clutch CL is disengaged (i.e., in the open state), it is transmitted only to the second electric generator MG2.

[0080] The first electric generator MG1 is an electric generator (so-called "traction motor") that is mechanically connected to the drive wheel DW and used as the drive source of the vehicle 1. As the first electric generator MG1, for example, an AC motor (more specifically, a three-phase AC motor) can be used.

[0081] Furthermore, the first electric generator MG1 is electrically connected to the storage battery BAT and the second electric generator MG2 via the power conversion device 10 described later. The first electric generator MG1 operates as an electric motor by being supplied with power from at least one of the storage battery BAT and the second electric generator MG2, and outputs power. The power output from the first electric generator MG1 is transmitted to the drive wheels DW. That is, the vehicle 1 moves by transmitting power from at least one of the engine ENG and the first electric generator MG1 to the drive wheels DW.

[0082] In addition, the first electric generator MG1 sometimes performs regenerative operation as a generator to generate electricity when the vehicle 1 brakes (so-called "regenerative power generation"). The electricity generated by the regenerative operation of the first electric generator MG1 (hereinafter also referred to as "regenerative power") can be supplied to the storage battery BAT via the power conversion device 10. Thus, the storage battery BAT can be charged by regenerative power.

[0083] The second electric generator MG2 is an electric generator mechanically connected to the engine ENG and used as a generator to generate electricity using the power of the engine ENG. Furthermore, the second electric generator MG2 is electrically connected to the battery BAT and the first electric generator MG1 via a power conversion device 10. The electricity generated by the second electric generator MG2 is supplied to at least one of the battery BAT and the first electric generator MG1 via the power conversion device 10. Thus, the battery BAT can be charged using the electricity generated by the second electric generator MG2, or the first electric generator MG1 can be driven.

[0084] The power conversion device 10 is a device that converts input power and outputs converted power (so-called a "power control unit"). In this embodiment, the power conversion device 10 is electrically connected to the first electric generator MG1, the second electric generator MG2, and the battery BAT, respectively, and converts the power transmitted between them.

[0085] More specifically, the power conversion device 10 is configured, for example, to house the first inverter 11, the second inverter 12, and the voltage conversion device 13 within a single housing. Here, the first inverter 11 and the second inverter 12 are devices that have multiple switching elements, through which direct current (DC) is converted to alternating current (AC), or vice versa. As switching elements for the first inverter 11 and the second inverter 12, MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) and IGBTs (Insulated Gate Bipolar Transistors) can be used, for example.

[0086] Additionally, the voltage conversion device 13 is a device that converts the input voltage into a specified voltage and outputs the converted voltage (also known as a "voltage control unit"). For example, a DC / DC converter can be used as the voltage conversion device 13. In this embodiment, the voltage conversion device 13 converts the voltage of the power supplied between the first electric generator MG1 or the second electric generator MG2 and the battery BAT.

[0087] For example, in vehicle 1, when the power of the battery BAT is supplied to the first electric generator MG1, after the output voltage of the battery BAT is boosted by the voltage conversion device 13, it is converted into AC power by the first inverter 11, and the AC power is supplied to the first electric generator MG1.

[0088] In addition, in vehicle 1, when regenerative power is generated by the first electric generator MG1, the AC power generated by the first electric generator MG1 as regenerative power is converted into DC power by the first inverter 11, and then the DC power is stepped down by the voltage conversion device 13, and the stepped-down DC power is supplied to the battery BAT.

[0089] Furthermore, in vehicle 1, when power is generated by the second electric generator MG2, the AC power generated from the second electric generator MG2 is converted into DC power by the second inverter 12, and then supplied to the first electric generator MG1 via the first inverter 11, or supplied to the battery BAT via the voltage conversion device 13. In this case, the first inverter 11 converts the DC power received from the second inverter 12 into AC power and outputs it to the first electric generator MG1. Additionally, the voltage conversion device 13 steps down the DC power received from the second inverter 12 and outputs the stepped-down DC power to the battery BAT.

[0090] The cooling device 20 is a device for cooling the power conversion device 10. For example, the cooling device 20 is a water-cooled cooling device and includes: a cooling circuit 21 for circulating cooling water (e.g., LLC (Long LifeCoolant)) as a refrigerant; and an electric pump 22 for pressurizing the cooling water in the cooling circuit 21.

[0091] The cooling circuit 21 exchanges heat between the cooling water and the power conversion device 10 (e.g., the housing that houses the first inverter 11, the second inverter 12, and the voltage conversion device 13), and also exchanges heat between the cooling water and the outside air. The cooling circuit 21 can be implemented, for example, by means of a water jacket, a radiator, or the like provided in the housing of the power conversion device 10.

[0092] The electric pump 22 is an electric pump driven by power from the storage battery BAT or by power generated by the second electric generator MG2, and is controlled, for example, by the control device 50 described later. The control device 50 controls the electric pump 22, for example, using PWM (Pulse Width Modulation) control.

[0093] Vehicle sensor 30 is a sensor that acquires various information related to vehicle 1 and outputs the acquired information to control device 50, which will be described later. The information acquired by vehicle sensor 30 is supplied to control device 50 for the control of vehicle 1 (hereinafter also referred to as "vehicle control").

[0094] Vehicle sensors 30 include, for example, a first current / voltage sensor 31, a second current / voltage sensor 32, a MOT speed sensor 33, a GEN speed sensor 34, a water temperature sensor 35, and an equipment temperature sensor 36.

[0095] The first current / voltage sensor 31 is a sensor that detects the current value (hereinafter also referred to as "I1 current") and voltage value (hereinafter also referred to as "V1 voltage") of the power supplied between the battery BAT and the voltage conversion device 13. The first current / voltage sensor 31 can be implemented, for example, by a current sensor and a voltage sensor provided on the power line connecting the battery BAT and the voltage conversion device 13.

[0096] The second current / voltage sensor 32 is a sensor that detects the current value (hereinafter also referred to as "I2 current") and voltage value (hereinafter also referred to as "V2 voltage") of the power supplied between the voltage conversion device 13 and the first inverter 11 and / or the second inverter 12. The second current / voltage sensor 32 can be implemented, for example, by a current sensor and a voltage sensor disposed on the power lines connecting the voltage conversion device 13 to the first inverter 11 and the second inverter 12.

[0097] The MOT speed sensor 33 is a sensor that detects the rotational speed (hereinafter also referred to as "MOT speed") of the first electric generator MG1. For example, the MOT speed sensor 33 can be implemented by a rotary transformer provided in the first electric generator MG1.

[0098] The GEN speed sensor 34 is a sensor that detects the rotational speed (hereinafter also referred to as "GEN speed") of the second electric generator MG2. For example, the GEN speed sensor 34 can be implemented by a rotary transformer provided in the second electric generator MG2.

[0099] The water temperature sensor 35 is a sensor that detects the temperature (hereinafter also referred to as "water temperature TW") of the cooling water circulating in the cooling circuit 21. For example, the water temperature sensor 35 can be implemented by a temperature sensor provided in the cooling circuit 21.

[0100] The device temperature sensor 36 is a sensor that detects the temperature of the power conversion device 10 (hereinafter also referred to as "device temperature Tj"). For example, the device temperature sensor 36 can be implemented by a temperature sensor disposed on a semiconductor chip that integrates the switching elements of the power conversion device 10.

[0101] In addition, although the illustrations and detailed descriptions are omitted, the vehicle sensor 30 may include, for example, a vehicle speed sensor that detects the driving speed of the vehicle 1 (hereinafter also referred to as "vehicle speed") and an AP sensor that detects the amount of operation of the accelerator pedal of the vehicle 1 (hereinafter also referred to as "AP (accelerator position)").

[0102] The control device 50 is a computer that provides unified control over the entire vehicle 1. For example, it may include: a processor 50a that performs various calculations; a storage unit 50b that has a non-transitory storage medium (e.g., ROM (Read Only Memory), RAM (Random Access Memory), or flash memory) for storing various information; and an I / F (interface) unit 50c that controls the input and output of internal and external data to the control device 50. For example, the control device 50 may be implemented through one or more ECUs (Electronic Control Units) working together.

[0103] The control device 50 controls the output of the engine ENG based on information obtained from the vehicle sensor 30, or controls the output of the first electric generator MG1 and / or the second electric generator MG2 via the power conversion device 10, or controls the state of the clutch CL, or controls the electric pump 22.

[0104] As an example, the control device 50 controls the driving mode of the vehicle 1. Here, the driving mode of the vehicle 1 may include, for example, EV (Electric Vehicle) driving mode, hybrid driving mode, and engine driving mode.

[0105] The EV driving mode is a driving mode in which only the power from the battery BAT is supplied to the first electric generator MG1, and the vehicle 1 is driven by the power output from the first electric generator MG1 based on this power. More specifically, in the EV driving mode, the control device 50 disengages the clutch CL and stops the engine ENG (i.e., the second electric generator MG2), supplying only the power from the battery BAT to the first electric generator MG1, thereby driving the first electric generator MG1 and making the vehicle 1 move.

[0106] The hybrid driving mode is a driving mode in which electricity generated by the second electric generator MG2 is supplied to the first electric generator MG1, and the vehicle 1 is driven primarily by the power output of the first electric generator MG1 based on this electricity. More specifically, in the hybrid driving mode, the control device 50 disengages the clutch CL, and the second electric generator MG2 generates electricity using the power of the engine ENG. Furthermore, the control device 50 drives the first electric generator MG1 by supplying the electricity generated by the second electric generator MG2 to the first electric generator MG1, thereby driving the vehicle 1. Additionally, in the hybrid driving mode, the control device 50 may also appropriately supply power from the battery BAT to the first electric generator MG1.

[0107] The engine driving mode is a driving mode in which the vehicle 1 is driven primarily by the power output of the engine ENG. More specifically, in engine driving mode, the control device 50 engages the clutch CL to operate the engine ENG. In addition, in engine driving mode, the control device 50 can also appropriately supply power from the battery BAT to the first electric generator MG1, and use the power output of the first electric generator MG1 to drive the vehicle 1.

[0108] As another example, control device 50 derives the saturation temperature Tsat and the loss at saturation temperature PlsTsat, which will be described later, and controls vehicle 1 based on the saturation temperature Tsat and / or the loss at saturation temperature PlsTsat. Hereinafter, specific examples of the control performed by control device 50 in this case will be described in detail.

[0109] [2. Functional Structure of the Control Device]

[0110] Figure 2 This is a block diagram illustrating an example of the functional structure of the control device 50. For example... Figure 2As shown, the control device 50 includes, for example, a loss characteristic derivation unit 51, a flow rate derivation unit 52, a thermal resistance derivation unit 53, a thermal resistance characteristic derivation unit 54, a loss derivation unit at saturation temperature / saturation temperature 55, and a vehicle control unit 56. Each functional unit of the loss characteristic derivation unit 51, flow rate derivation unit 52, thermal resistance derivation unit 53, thermal resistance characteristic derivation unit 54, loss derivation unit at saturation temperature / saturation temperature 55, and vehicle control unit 56 can be implemented, for example, by executing a program stored in the storage unit 50b via the processor 50a or via the I / F unit 50c.

[0111] The loss characteristic derivation unit 51 derives the loss characteristic Lc based on the operating conditions of the first electric generator MG1, and transmits the processing result to the thermal resistance characteristic derivation unit 54 and the loss derivation unit 55 at saturation temperature / saturation temperature. The loss characteristic Lc represents the loss of the power conversion device 10 at each temperature (i.e., equipment temperature Tj) when the first electric generator MG1 is operating under these operating conditions.

[0112] An example of the loss of the power conversion device 10 is the loss of the first inverter 11 (hereinafter also referred to as "MOT-INV loss"). Another example of the loss of the power conversion device 10 is the loss of the second inverter 12 (hereinafter also referred to as "GEN-INV loss"). Furthermore, another example of the loss of the power conversion device 10 is the loss of the voltage conversion device 13 (hereinafter also referred to as "VCU (Voltage Control Unit) loss"). That is, the loss of the power conversion device 10 can include MOT-INV loss, GEN-INV loss, and VCU loss.

[0113] In addition, the operating conditions of the first electric generator MG1 may include the MOT speed, the output torque of the first electric generator MG1 (hereinafter also referred to as "MOT torque"), and the V2 voltage.

[0114] For example, information representing the current MOT speed, MOT torque, and V2 voltage is input to the loss characteristic derivation unit 51. Furthermore, the control device 50 can, for example, acquire information representing the current MOT speed from the MOT speed sensor 33, and information representing the current V2 voltage from the second current / voltage sensor 32. Additionally, it can derive (i.e., acquire) information representing the current MOT torque based on the current MOT speed and V2 voltage. Moreover, the loss characteristic derivation unit 51 derives the loss characteristic Lc when the first electric generator MG1 is operating at the current MOT speed, MOT torque, and V2 voltage.

[0115] To be more specific, for example, a loss diagram Mp1 is pre-stored in the storage unit 50b. This loss diagram Mp1 represents information about the losses of the power conversion device 10 corresponding to various combinations of MOT speed, MOT torque, V2 voltage, and equipment temperature Tj. Here, the loss diagram Mp1 only needs to be information that allows the losses of the power conversion device 10 to be determined based on the MOT speed, MOT torque, V2 voltage, and equipment temperature Tj, and the data can be configured into multiple diagram (in other words, tables) groups. When the loss diagram Mp1 is configured into multiple diagram groups, the loss diagram Mp1 may, for example, include a diagram representing the losses of the power conversion device 10 corresponding to the combination of MOT speed, MOT torque, and V2 voltage at the first temperature T1 (described later) and a diagram representing the losses of the power conversion device 10 corresponding to the combination of MOT speed, MOT torque, and V2 voltage at the second temperature T2 (described later).

[0116] And, as Figure 2 As shown in the box marked with reference numeral 51a, the loss characteristic derivation unit 51 derives the loss PlsT1 at the first temperature with reference to the loss diagram Mp1. This loss PlsT1 at the first temperature is the loss of the power conversion device 10 under the current MOT speed, MOT torque, and V2 voltage (in other words, the current operating conditions of the first electric generator MG1) and the device temperature Tj is set to a predetermined first temperature T1. In this case, the loss characteristic derivation unit 51 derives the loss corresponding to the combination of the current MOT speed, MOT torque, and V2 voltage and the first temperature T1 as the device temperature Tj from the loss diagram Mp1 as the loss PlsT1 at the first temperature. Furthermore, here, the first temperature T1 is a temperature preset by the manufacturer of the vehicle 1, etc., and can be set to one of the temperatures that the device temperature Tj can reach when the vehicle 1 is running, such as 25°C.

[0117] In addition, such as Figure 2As shown in the box marked with reference numeral 51b, similar to the loss PlsT1 at the first temperature, the loss characteristic derivation unit 51 also derives the loss PlsT2 at the second temperature. This second temperature loss PlsT2 is the loss of the power conversion device 10 under the current MOT speed, MOT torque, and V2 voltage, and with the device temperature Tj set to a predetermined second temperature T2. That is, the loss characteristic derivation unit 51 derives the loss corresponding to the combination of the current MOT speed, MOT torque, and V2 voltage and the second temperature T2 as the device temperature Tj in the loss diagram Mp1 as the second temperature loss PlsT2. Furthermore, here, the second temperature T2 is a temperature preset by the manufacturer of the vehicle 1, etc., and is a temperature different from the first temperature T1. For example, the second temperature T2 can be set to one of the temperatures that the device temperature Tj can reach when the vehicle 1 is running, and is a temperature higher than the first temperature T1 (e.g., 25 [°C]), i.e., 175 [°C].

[0118] Furthermore, the loss characteristic derivation unit 51 derives the loss characteristic Lc based on the loss PlsT1 at the first temperature and the loss PlsT2 at the second temperature. The loss characteristic Lc can, for example, be calculated geometrically based on the loss PlsT1 at the first temperature and the loss PlsT2 at the second temperature. To explain more specifically, as follows... Figure 2 As shown in the box marked with reference numeral 51c, the loss characteristic derivation unit 51, for example, in a plane where the horizontal axis is the loss of the power conversion device 10 and the vertical axis is the equipment temperature Tj, can derive the line segment passing through coordinate point P1 (PlsT1, T1) and coordinate point P2 (PlsT2, T2) as the loss characteristic Lc.

[0119] Furthermore, here, the loss characteristic derivation unit 51 derives the loss characteristic Lc based on two losses corresponding to different device temperatures Tj, such as the loss PlsT1 at the first temperature and the loss PlsT2 at the second temperature, but is not limited to this. For example, the loss characteristic derivation unit 51 may also derive the loss characteristic Lc based on three or more losses corresponding to different device temperatures Tj.

[0120] Furthermore, here, the loss characteristic derivation unit 51 derives the loss characteristic Lc based on the current operating conditions of the first electric generator MG1, but is not limited thereto. For example, as described later, the loss characteristic derivation unit 51 can also derive the loss characteristic Lc when the first electric generator MG1 is operating under specified operating conditions (e.g., a specified V2 voltage).

[0121] The flow rate output unit 52, based on the water temperature TW (i.e., the temperature of the cooling water) detected by the water temperature sensor 35 and the driving state of the electric pump 22, outputs the flow rate Fw of the cooling water pumped by the electric pump 22 per unit time, and transmits this processing result to the thermal resistance output unit 53. The driving state of the electric pump 22 can be set, for example, to the duty cycle (hereinafter also simply referred to as "Duty") of the electric pump 22 under PWM control. The flow rate Fw is an example of the cooling conditions under which the cooling device 20 cools the power conversion device 10.

[0122] For example, the flow output unit 52 is input with information indicating the current water temperature TW (hereinafter also referred to as "water temperature TWnow") and the Duty indicating the current driving state of the electric pump 22. Furthermore, the flow output unit 52 outputs the current flow rate Fw based on the water temperature TWnow and the current Duty.

[0123] To be more specific, for example, a flow rate map Mp2 is pre-stored in the storage unit 50b. This flow rate map Mp2 represents information about the flow rate Fw corresponding to the combination of each Duty and water temperature TW. Furthermore, as... Figure 2 As shown in the box marked with reference numeral 52a in the attached diagram, the flow rate derivation unit 52 derives the flow rate Fw corresponding to the combination of the current water temperature TW (i.e., water temperature TWnow) and Duty, referring to the flow rate diagram Mp2. Figure 2 In the example shown, the current Duty is X[%], so Fw1 corresponding to the combination of water temperature TWnow and DutyX[%] is derived as flow rate Fw.

[0124] Furthermore, here, the flow export unit 52 exports the flow rate Fw based on the current Duty, but is not limited to this. For example, as described later, the flow export unit 52 can also export the flow rate Fw when the electric pump 22 is driven under a specified Duty.

[0125] The thermal resistance output unit 53 outputs the thermal resistance Rt of the power conversion device 10 under the cooling conditions of the cooling device 20 cooling the power conversion device 10, and transmits the processing result to the thermal resistance characteristic output unit 54.

[0126] For example, the thermal resistance derivation unit 53 derives the thermal resistance Rt based on the flow rate Fw derived by the flow rate derivation unit 52. More specifically, for example, a thermal resistance diagram Mp3 is pre-stored in the storage unit 50b, which represents information about the thermal resistance Rt corresponding to each flow rate Fw. Furthermore, as... Figure 2 As shown in the box marked with reference numeral 53a, for example, when the flow rate Fw exported by the flow export unit 52 is Fw1, the thermal resistance export unit 53 exports Rt1 corresponding to Fw1 as thermal resistance Rt.

[0127] Furthermore, while the thermal resistance output unit 53 derives the thermal resistance Rt based on the flow rate Fw output by the flow rate output unit 52, it is not limited to this. For example, if the vehicle 1 is equipped with a flow sensor capable of detecting the flow rate Fw, the thermal resistance output unit 53 may also derive the thermal resistance Rt based on the flow rate Fw detected by that flow sensor. In such a case, the control device 50 may not need to include the flow rate output unit 52.

[0128] The thermal resistance characteristic derivation unit 54 derives the thermal resistance characteristic Rc representing the arrival temperature of each loss of the power conversion device 10 based on the loss characteristic Lc derived by the loss characteristic derivation unit 51 and the thermal resistance Rt derived by the thermal resistance derivation unit 53, and transmits the processing result to the loss derivation unit 55 at saturation temperature / saturation temperature.

[0129] For example, by deriving the loss characteristic Lc, which includes the loss PlsT1 at the first temperature and the loss PlsT2 at the second temperature, the thermal resistance Rt is derived as Rt1. In this case, as... Figure 2 As shown in the box marked with reference numeral 54a, the thermal resistance characteristic derivation unit 54 derives, for example, the first arrival temperature T11 by the following equation (1). This first arrival temperature T11 is the arrival temperature of the power conversion device 10 when the loss of the power conversion device 10 is set to the loss PlsT1 at the first temperature and the thermal resistance Rt is set to Rt1. Furthermore, the thermal resistance characteristic derivation unit 54 also derives, for example, the second arrival temperature T12 by the following equation (1). This second arrival temperature T12 is the arrival temperature of the power conversion device 10 when the loss of the power conversion device 10 is set to the loss PlsT2 at the second temperature and the thermal resistance Rt is set to Rt1. In addition, "TW0" in the following equation (1) can be set to the water temperature TWnow, for example.

[0130] The temperature reached by the power conversion device 10 = thermal resistance Rt × power conversion device 10 loss + TW0 (1)

[0131] Furthermore, the thermal resistance characteristic derivation unit 54 derives the thermal resistance characteristic Rc based on the first arrival temperature T11 and the second arrival temperature T12. The thermal resistance characteristic Rc can be calculated geometrically based on the first arrival temperature T11 and the second arrival temperature T12. To explain in more detail, as follows... Figure 2 As shown in the box marked with reference numeral 54a in the figure, the thermal resistance characteristic derivation section 54, for example, in a plane in which the loss of the power conversion device 10 is taken on the horizontal axis and the device temperature Tj is taken on the vertical axis, can derive the line segment passing through the coordinate point P11 (PlsT1, T11) and the coordinate point P12 (PlsT2, T12) as the thermal resistance characteristic Rc.

[0132] The loss derivation unit 55 at saturation temperature / saturation temperature derives the saturation temperature Tsat and the loss PlsTsat at saturation temperature based on the loss characteristic Lc derived by the loss characteristic derivation unit 51 and the thermal resistance characteristic Rc derived by the thermal resistance characteristic derivation unit 54.

[0133] Here, the saturation temperature Tsat is the temperature reached by the power conversion device 10 under specified operating conditions, where the first electric generator MG1 is operated under specified operating conditions and the power conversion device 10 is cooled under specified cooling conditions. For example, in Figure 2 In the example shown, the saturation temperature Tsat becomes the temperature reached by the power conversion device 10 when the first electric generator MG1 is operating under the current operating conditions and the power conversion device 10 is being cooled under the current cooling conditions. Furthermore, the loss at the saturation temperature PlsTsat is the loss of the power conversion device 10 when the device temperature Tj is equal to the saturation temperature Tsat.

[0134] The saturation temperature Tsat and the loss PlsTsat at the saturation temperature can be calculated geometrically from the loss characteristic Lc and the thermal resistance characteristic Rc. To be more specific, it is as follows: Figure 2 As shown in the box marked with reference numeral 55a in the attached drawing, the loss derivation section 55 at saturation temperature / saturation temperature, for example, in a plane where the horizontal axis represents the loss of the power conversion device 10 and the vertical axis represents the device temperature Tj, derives the loss of the power conversion device 10 corresponding to the intersection point CP of the loss characteristic Lc and the thermal resistance characteristic Rc as the loss PlsTsat at saturation temperature, and derives the device temperature Tj corresponding to the intersection point CP as the saturation temperature Tsat. That is, the saturation temperature Tsat can be referred to as the device temperature Tj where the loss (in other words, heat generation) of the power conversion device 10 reaches equilibrium with the thermal resistance Rt, or it can be referred to as the device temperature Tj where the temperature rise of the power conversion device 10 caused by the loss of the power conversion device 10 stops.

[0135] In this way, the control device 50 derives the loss of the power conversion device 10 corresponding to the intersection point CP of the loss characteristic Lc and the thermal resistance characteristic Rc as the loss PlsTsat at the saturation temperature, and derives the equipment temperature Tj corresponding to the intersection point CP as the saturation temperature Tsat. Thus, the saturation temperature Tsat and the loss PlsTsat at the saturation temperature can be calculated with good accuracy through simple calculations. Furthermore, the control device 50 can also predict the saturation temperature Tsat and the loss PlsTsat at the saturation temperature before the actual equipment temperature Tj reaches the saturation temperature Tsat.

[0136] The vehicle control unit 56 reflects the saturation temperature Tsat and / or the loss at saturation temperature PlsTsat derived by the loss at saturation temperature derived unit 55 into the vehicle control, without particularly limiting the vehicle control. For example, the vehicle control unit 56 can control the electric pump 22 or the power conversion device 10 based on the saturation temperature Tsat and / or the loss at saturation temperature PlsTsat. In addition, the vehicle control unit 56 can also determine the state of the vehicle 1 (e.g., presence or absence of abnormalities, load status) based on the saturation temperature Tsat and / or the loss at saturation temperature PlsTsat. Specific examples of vehicle control based on the saturation temperature Tsat and / or the loss at saturation temperature PlsTsat will be described later as the first to fourth examples of the present invention, and therefore the description is omitted here. Furthermore, the vehicle control unit 56 is an example of a moving body control unit in the present invention.

[0137] [3. Processing executed by the control department]

[0138] Next, an example of the processing performed by the control device 50 will be described. Figure 3 This is a flowchart illustrating an example of the processing performed by the control device 50. For example, during the starting of the vehicle 1 (e.g., when the ignition power is turned on), the control device 50 performs processing at predetermined intervals (e.g., every 1 [s]). Figure 3 The series of processes shown.

[0139] like Figure 3 As shown, firstly, the control device 50 acquires information, for example, representing the current MOT speed, MOT torque, V2 voltage, water temperature TW (i.e., water temperature TWnow), and the duty of the electric pump 22 (step Sp1). Additionally, during the processing in step Sp1, the control device 50 may also acquire information representing the I1 current and V1 voltage as needed.

[0140] Next, based on the MOT speed, MOT torque and V2 voltage obtained through the process in step Sp1, the control device 50 derives the loss PlsT1 at the first temperature and the loss PlsT2 at the second temperature with reference to the loss diagram Mp1 (step Sp2).

[0141] Next, the control device 50 derives the loss characteristic Lc of the power conversion device 10 based on the loss PlsT1 at the first temperature and the loss PlsT2 at the second temperature derived through the processing in step Sp2 (step Sp3).

[0142] Next, the control device 50 derives the current flow rate Fw based on the water temperature TWnow and Duty obtained through the process in step Sp1, referring to the flow rate diagram Mp2 (step Sp4).

[0143] Next, the control device 50 derives the thermal resistance Rt of the power conversion device 10 based on the flow rate Fw derived through the processing in step Sp4, referring to the thermal resistance diagram Mp3 (step Sp5).

[0144] Next, the control device 50 derives the thermal resistance characteristic Rc of the power conversion device 10 based on the loss PlsT1 at the first temperature and the loss PlsT2 at the second temperature derived through the process of step Sp2, and the thermal resistance Rt derived through the process of step Sp5 (step Sp6).

[0145] Next, the control device 50 derives the saturation temperature Tsat and the loss PlsTsat at the saturation temperature based on the loss characteristic Lc derived through the process of step Sp3 and the thermal resistance characteristic Rc derived through the process of step Sp6 (step Sp7).

[0146] Furthermore, the control device 50 controls the vehicle 1 based on the saturation temperature Tsat and / or the loss PlsTsat at the saturation temperature derived through the processing in step Sp7 (step Sp8), and then ends. Figure 3 The series of processes shown.

[0147] As explained above, according to the control device 50, the saturation temperature Tsat and the loss PlsTsat at the saturation temperature can be derived when the first electric generator MG1 is operating under current operating conditions and the power conversion device 10 is being cooled under current cooling conditions. Therefore, vehicle control that takes into account the saturation temperature Tsat and / or the loss PlsTsat at the saturation temperature can be performed. Furthermore, this can contribute to improving the energy efficiency of the vehicle 1.

[0148] Furthermore, as operating conditions for the first electric generator MG1, the control device 50 derives the loss characteristic Lc based, for example, on the MOT speed, MOT torque, and V2 voltage, where V2 voltage is the voltage value of the power supplied between the first electric generator MG1 and the power conversion device 10. Thus, the loss characteristic Lc, taking into account the MOT speed, MOT torque, and V2 voltage, can be derived.

[0149] Furthermore, the control device 50, acting as the cooling condition for the power conversion device 10, derives the flow rate Fw based on the water temperature TW detected by the water temperature sensor 35 and the driving state (e.g., duty) of the electric pump 22, and derives the thermal resistance Rt based on the derived flow rate Fw. Thus, even without providing a flow sensor to detect the flow rate Fw of the cooling water pumped by the electric pump 22, the thermal resistance Rt can be appropriately derived.

[0150] Furthermore, in the examples described above, the operating conditions of the first electric generator MG1 used by the control device 50 in deriving the saturation temperature Tsat and the loss PlsTsat at the saturation temperature are set to the current operating conditions, but this is not a limitation. For example, the control device 50 may use any operating condition (e.g., a specified V2 voltage) instead of the current operating conditions of the first electric generator MG1 (e.g., the current V2 voltage), and then derive the saturation temperature Tsat and the loss PlsTsat at the saturation temperature. Thus, for example, it is possible to derive the saturation temperature Tsat and the loss PlsTsat at the saturation temperature when the first electric generator MG1 is operating under arbitrary operating conditions and the power conversion device 10 is cooled under the current cooling conditions.

[0151] Furthermore, in the example described above, the control device 50 sets the cooling conditions of the power conversion device 10 used in deriving the saturation temperature Tsat and the loss PlsTsat at the saturation temperature to the current cooling conditions, but is not limited to this. For example, the control device 50 may also use any cooling condition (e.g., a specified duty) instead of the current cooling conditions of the power conversion device 10 (e.g., the current duty of the electric pump 22) to derive the saturation temperature Tsat and the loss PlsTsat at the saturation temperature. Thus, for example, it is possible to derive the saturation temperature Tsat and the loss PlsTsat at the saturation temperature when the first electric generator MG1 is operating under the current operating conditions and the power conversion device 10 is cooled under any cooling conditions.

[0152] Furthermore, in the example described above, the control device 50 derives the saturation temperature Tsat and the loss at saturation temperature PlsTsat based on the operating conditions of the first electric generator MG1, but is not limited thereto. For example, the control device 50 may derive the saturation temperature Tsat and the loss at saturation temperature PlsTsat based on the operating conditions of the first electric generator MG1, or, in addition to the saturation temperature Tsat and the loss at saturation temperature PlsTsat based on the operating conditions of the first electric generator MG1, also derive the saturation temperature Tsat and the loss at saturation temperature PlsTsat based on the operating conditions of the second electric generator MG2. The operating conditions of the second electric generator MG2 may include, for example, the GEN speed, the output torque of the second electric generator MG2 (hereinafter also referred to as "GEN torque"), and the V2 voltage. In this case, the control device 50 may, for example, obtain information representing the GEN speed from the GEN speed sensor 34, obtain information representing the V2 voltage from the second current / voltage sensor 32, and further, derive information representing the GEN torque based on the GEN speed and the V2 voltage.

[0153] Furthermore, the control device 50 can also derive the saturation temperature Tsat and the loss PlsTsat at the saturation temperature based on the operating conditions of the voltage conversion device 13. The operating conditions of the voltage conversion device 13 may include, for example, the I1 current, V1 voltage, V2 voltage, etc. In this case, the control device 50 can, for example, obtain information representing the I1 current and V1 voltage from the first current / voltage sensor 31, and information representing the V2 voltage from the second current / voltage sensor 32.

[0154] [4. First Application Example]

[0155] Next, a first application example of the present invention will be described. This first application example is an example in which the control device 50 controls the electric pump 22 based on the loss PlsTsat at the saturation temperature. Furthermore, in the first application example, the control device 50 derives the first saturation temperature Tsat1, the second saturation temperature Tsat2, and the third saturation temperature Tsat3 as the saturation temperature Tsat, and derives the losses PlsTsat1, PlsTsat2, and PlsTsat3 at the first saturation temperature as the loss PlsTsat at the saturation temperature.

[0156] Here, the first saturation temperature Tsat1 is the saturation temperature Tsat based on the MOT-INV loss (i.e., the operating conditions of the first electric generator MG1). The loss PlsTsat1 at the first saturation temperature is the loss PlsTsat at the saturation temperature based on the MOT-INV loss. Specific examples of deriving the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature will be used... Figure 4 More details will follow later.

[0157] Furthermore, the second saturation temperature Tsat2 is the saturation temperature Tsat based on the GEN-INV loss (i.e., the operating conditions of the second electric generator MG2). The loss PlsTsat2 at the second saturation temperature is the loss PlsTsat at the saturation temperature based on the GEN-INV loss. Specific examples of deriving the second saturation temperature Tsat2 and the loss PlsTsat2 at the second saturation temperature will be used... Figure 5 More details will follow later.

[0158] Furthermore, the third saturation temperature Tsat3 is the saturation temperature Tsat based on the VCU loss (i.e., the operating conditions of the voltage conversion device 13). The loss PlsTsat3 at the third saturation temperature is the loss PlsTsat at the saturation temperature based on the VCU loss. Specific examples of deriving the third saturation temperature Tsat3 and the loss PlsTsat3 at the third saturation temperature will be used... Figure 6 More details will follow later.

[0159] That is, in the first application example, the control device 50 derives the saturation temperature Tsat and the loss at saturation temperature PlsTsat for each of the various electric generators in the vehicle 1, such as the first electric generator MG1 and the second electric generator MG2. Thus, even when the vehicle 1 has multiple electric generators, vehicle control that takes into account the saturation temperature Tsat and / or the loss at saturation temperature PlsTsat corresponding to each electric generator is possible.

[0160] (4-1. The method for deriving the first saturation temperature and the loss at the first saturation temperature in the first application example)

[0161] First, the method for deriving the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature in the first utilization example will be explained. Figure 4 This is a diagram illustrating an example of the method for deriving the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature in the first utilization example.

[0162] In the first example of use, such as Figure 4 As shown in the box marked with reference numeral 401, the control device 50 (e.g., loss characteristic derivation unit 51) derives the loss PlsT1a at a first temperature, for example, by referring to the loss diagram Mp1a. This loss PlsT1a at the first temperature is the MOT-INV loss under the current MOT speed, MOT torque, and V2 voltage, and with the equipment temperature Tj set to 25 [°C]. Here, the loss diagram Mp1a represents information about the MOT-INV loss corresponding to each combination of MOT speed, MOT torque, V2 voltage, and equipment temperature Tj, and is, for example, pre-stored in the storage unit 50b. Furthermore, the loss diagram Mp1a only needs to be able to determine the MOT-INV loss information based on the MOT speed, MOT torque, V2 voltage, and equipment temperature Tj, and like the loss diagram Mp1, the data can be configured into multiple groups.

[0163] In addition, such as Figure 4 As shown in the box marked with reference numeral 401, similar to the loss PlsT1a at the first temperature, the control device 50 also derives the loss PlsT2a at the second temperature and the loss PlsT3a at the third temperature. Here, the loss PlsT2a at the second temperature can, for example, be set as the MOT-INV loss under the current MOT speed, MOT torque, and V2 voltage, and with the equipment temperature Tj set to 75 [°C]. Similarly, the loss PlsT3a at the third temperature can, for example, be set as the MOT-INV loss under the current MOT speed, MOT torque, and V2 voltage, and with the equipment temperature Tj set to 175 [°C].

[0164] Next, the control device 50 (e.g., the loss characteristic derivation unit 51) as follows Figure 4 As shown in the box marked with reference numeral 402, the MOT-INV loss characteristic Lc1, representing the MOT-INV loss at each device temperature Tj, is derived based on the losses PlsT1a at the first temperature, PlsT2a at the second temperature, and PlsT3a at the third temperature. The MOT-INV loss characteristic Lc1 is an example of the loss characteristic Lc, and like the loss characteristic Lc, it can be obtained geometrically, for example, from the losses PlsT1a at the first temperature, PlsT2a at the second temperature, and PlsT3a at the third temperature.

[0165] Next, as Figure 4 As shown in the box marked with reference numeral 403, the control device 50 (e.g., flow output unit 52) ​​outputs the flow rate Fw of the electric pump 22 for each Duty, corresponding to the water temperature TWnow, with reference to the flow rate diagram Mp2. For example, as... Figure 4 As shown, the control device 50 outputs the flow rates Fw for the cases where the duty of the electric pump 22 is set to 40%, 60%, and 80%. Figure 4 In the example shown, Fw1 is derived as the flow rate Fw when the Duty of the electric pump 22 is set to 40%, Fw2 is derived as the flow rate Fw when the Duty of the electric pump 22 is set to 60%, and Fw3 is derived as the flow rate Fw when the Duty of the electric pump 22 is set to 80%.

[0166] Next, as Figure 4 As shown in the box marked with reference numeral 404, the control device 50 (e.g., thermal resistance output unit 53) outputs the thermal resistance Rt corresponding to each flow rate Fw based on the flow rate Fw output through the above-described process, referring to the thermal resistance diagram Mp3. Figure 4 In the example shown, Rt1 is derived from the thermal resistance Rt when the flow rate Fw is Fw1 (in other words, when the Duty is set to 40%); Rt2 is derived from the thermal resistance Rt when the flow rate Fw is Fw2 (in other words, when the Duty is set to 60%); and Rt3 is derived from the thermal resistance Rt when the flow rate Fw is Fw3 (in other words, when the Duty is set to 80%).

[0167] Next, as Figure 4 As shown in the box marked with reference numeral 405, the control device 50 (e.g., thermal resistance characteristic derivation unit 54) derives the thermal resistance characteristic Rc corresponding to each thermal resistance Rt based on the thermal resistance Rt derived through the above-described process. Figure 4In the example shown, thermal resistance characteristic Rc1a is derived from the thermal resistance characteristic Rc when the thermal resistance Rt is Rt1 (in other words, when the duty is set to 40%). Furthermore, thermal resistance characteristic Rc2a is derived from the thermal resistance characteristic Rc when the thermal resistance Rt is Rt2 (in other words, when the duty is set to 60%). And furthermore, thermal resistance characteristic Rc3a is derived from the thermal resistance characteristic Rc when the thermal resistance Rt is Rt3 (in other words, when the duty is set to 80%).

[0168] For example, the thermal resistance characteristic Rc1a can be geometrically determined based on the first arrival temperature when the loss of the power conversion device 10 is set to the loss PlsT1a at the first temperature and the thermal resistance Rt is set to Rt1, the second arrival temperature when the loss of the power conversion device 10 is set to the loss PlsT2a at the second temperature and the thermal resistance Rt is set to Rt1, and the third arrival temperature when the loss of the power conversion device 10 is set to the loss PlsT3a at the third temperature and the thermal resistance Rt is set to Rt1. Furthermore, the first arrival temperature, the second arrival temperature, and the third arrival temperature can be determined, for example, by the above equation (1). Additionally, the thermal resistance characteristics Rc2a and Rc3a can also be determined in the same way as the thermal resistance characteristic Rc1a.

[0169] Next, as Figure 4 As shown in the box marked with reference numeral 406, the control device 50 (e.g., the loss derivation unit 55 at saturation temperature / saturation temperature) derives the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature for each thermal resistance characteristic Rc based on the MOT-INV loss characteristic Lc1 and each thermal resistance characteristic Rc derived through the above processing.

[0170] For example, based on the MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc1a, the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature can be calculated as the intersection of the MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc1a in a plane where the loss of the power conversion device 10 (in this case, the MOT-INV loss) is taken on the horizontal axis and the device temperature Tj is taken on the vertical axis. Figure 4In the example shown, TsatA is derived as the first saturation temperature Tsat1 based on the MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc1a, and PlsTsatA is derived as the loss PlsTsat1 at the first saturation temperature based on the MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc1a. Furthermore, the first saturation temperature Tsat1 based on the MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc1a, and the loss PlsTsat1 at the first saturation temperature, can also be described as the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature when the duty of the electric pump 22 is set to 40 [%).

[0171] Similarly, the control device 50 also derives the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature based on the MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc2a, and the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature based on the MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc3a. Thus, the control device 50 is able to obtain the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature for each thermal resistance characteristic Rc, in other words, for each duty of the electric pump 22.

[0172] (4-2. Method for deriving the loss at the second saturation temperature in the first application example)

[0173] Next, the method for deriving the second saturation temperature Tsat2 and the loss PlsTsat2 at the second saturation temperature in the first utilization example will be explained. Figure 5 This is a diagram illustrating an example of the method for deriving the loss PlsTsat2 at the second saturation temperature and the second saturation temperature in the first utilization example.

[0174] In the first example of use, such as Figure 5As shown in the box marked with reference numeral 501, the control device 50 (e.g., loss characteristic derivation unit 51) derives the loss PlsT1b at a first temperature, for example, by referring to the loss diagram Mp1b. This first temperature loss PlsT1b is the GEN-INV loss under the current GEN speed, GEN torque, and V2 voltage, with the equipment temperature Tj set to 25°C. Here, the loss diagram Mp1b represents information about the GEN-INV loss corresponding to each combination of GEN speed, GEN torque, V2 voltage, and equipment temperature Tj, and is, for example, pre-stored in the storage unit 50b. Furthermore, the loss diagram Mp1b only needs to be able to determine the GEN-INV loss information based on the GEN speed, GEN torque, V2 voltage, and equipment temperature Tj, and like the loss diagram Mp1, it can also be configured into multiple groups of data.

[0175] In addition, such as Figure 5 As shown in the box marked with reference numeral 501, similar to the loss PlsT1b at the first temperature, the control device 50 also derives the loss PlsT2b at the second temperature and the loss PlsT3b at the third temperature. Here, the loss PlsT2b at the second temperature can, for example, be set as the GEN-INV loss under the current GEN speed, GEN torque, and V2 voltage, and with the device temperature Tj set to 75 [°C]. Similarly, the loss PlsT3b at the third temperature can, for example, be set as the GEN-INV loss under the current GEN speed, GEN torque, and V2 voltage, and with the device temperature Tj set to 175 [°C].

[0176] Next, as Figure 5 As shown in the box marked with reference numeral 502, the control device 50 (e.g., loss characteristic derivation unit 51) derives a GEN-INV loss characteristic Lc2, representing the GEN-INV loss at each device temperature Tj, based on the loss PlsT1b at the first temperature, the loss PlsT2b at the second temperature, and the loss PlsT3b at the third temperature. The GEN-INV loss characteristic Lc2 is another example of the loss characteristic Lc, and like the loss characteristic Lc, it can be calculated geometrically, for example, based on the loss PlsT1b at the first temperature, the loss PlsT2b at the second temperature, and the loss PlsT3b at the third temperature.

[0177] Next, as Figure 5 As shown in the box marked with reference numeral 503, the control device 50 (e.g., flow output unit 52) ​​outputs the flow rate Fw of the electric pump 22 for each Duty, corresponding to the water temperature TWnow, with reference to the flow rate diagram Mp2. Figure 5In the example shown, Fw1 is derived as the flow rate Fw when the Duty of the electric pump 22 is set to 40%, Fw2 is derived as the flow rate Fw when the Duty of the electric pump 22 is set to 60%, and Fw3 is derived as the flow rate Fw when the Duty of the electric pump 22 is set to 80%.

[0178] also, Figure 5 The processing shown in the box marked with reference numeral 503 in the figure is related to Figure 4 The process shown in the box marked with reference numeral 403 is the same as the process described in the figure. Therefore, the control device 50 only needs to execute... Figure 4 The process shown in the box marked with reference numeral 403 in the attached drawing can also be skipped. Figure 5 The treatment shown in the box marked with reference numeral 503 in the attached figure is not used as is. Figure 4 The processing result is shown in the box marked with reference numeral 403 in the attached figure.

[0179] Next, as Figure 5 As shown in the box marked with reference numeral 504, the control device 50 (e.g., thermal resistance output unit 53) outputs the thermal resistance Rt corresponding to each flow rate Fw based on the flow rate Fw output through the above-described process, referring to the thermal resistance diagram Mp3. Figure 5 In the example shown, Rt1 is derived from the thermal resistance Rt when the flow rate Fw is Fw1 (in other words, when the Duty is set to 40%); Rt2 is derived from the thermal resistance Rt when the flow rate Fw is Fw2 (in other words, when the Duty is set to 60%); and Rt3 is derived from the thermal resistance Rt when the flow rate Fw is Fw3 (in other words, when the Duty is set to 80%).

[0180] also, Figure 5 The processing shown in the box marked with reference numeral 504 in the attached figure is related to Figure 4 The process shown in the box marked with reference numeral 404 is the same as the process described in the figure. Therefore, the control device 50 only needs to execute... Figure 4 The process shown in the box marked with reference numeral 404 in the attached drawing can also be skipped. Figure 5 The treatment shown in the box marked with reference numeral 504 in the attached figure is not used as is. Figure 4 The processing result is shown in the box marked with reference numeral 404 in the attached figure.

[0181] Next, as Figure 5 As shown in the box marked with reference numeral 505, the control device 50 (e.g., thermal resistance characteristic derivation unit 54) derives the thermal resistance characteristic Rc corresponding to each thermal resistance Rt based on the thermal resistance Rt derived through the above-described process. Figure 5In the example shown, thermal resistance characteristic Rc1b is derived from the thermal resistance characteristic Rc when the thermal resistance Rt is Rt1 (in other words, when the duty is set to 40%). Furthermore, thermal resistance characteristic Rc2b is derived from the thermal resistance characteristic Rc when the thermal resistance Rt is Rt2 (in other words, when the duty is set to 60%). And furthermore, thermal resistance characteristic Rc3b is derived from the thermal resistance characteristic Rc when the thermal resistance Rt is Rt3 (in other words, when the duty is set to 80%).

[0182] For example, the thermal resistance characteristic Rc1b can be geometrically determined based on the first arrival temperature when the loss of the power conversion device 10 is set to the loss PlsT1b at the first temperature and the thermal resistance Rt is set to Rt1, the second arrival temperature when the loss of the power conversion device 10 is set to the loss PlsT2b at the second temperature and the thermal resistance Rt is set to Rt1, and the third arrival temperature when the loss of the power conversion device 10 is set to the loss PlsT3b at the third temperature and the thermal resistance Rt is set to Rt1. Furthermore, the first arrival temperature, the second arrival temperature, and the third arrival temperature can be determined, for example, by the above equation (1). Additionally, the thermal resistance characteristics Rc2b and Rc3b can also be determined in the same way as the thermal resistance characteristic Rc1b.

[0183] Next, as Figure 5 As shown in the box marked with reference numeral 506, the control device 50 (e.g., the loss derivation unit 55 at saturation temperature / saturation temperature) derives the second saturation temperature Tsat2 and the loss PlsTsat2 at the second saturation temperature for each thermal resistance characteristic Rc based on the GEN-INV loss characteristic Lc2 and each thermal resistance characteristic Rc derived through the above processing.

[0184] For example, based on the GEN-INV loss characteristic Lc2 and the thermal resistance characteristic Rc1b, the second saturation temperature Tsat2 and the loss PlsTsat2 at the second saturation temperature can be calculated as the intersection of the GEN-INV loss characteristic Lc2 and the thermal resistance characteristic Rc1b in a plane where the loss of the power conversion device 10 (here, the GEN-INV loss) is taken on the horizontal axis and the device temperature Tj is taken on the vertical axis. Figure 5In the example shown, TsatB is derived as the second saturation temperature Tsat2 based on the GEN-INV loss characteristic Lc2 and the thermal resistance characteristic Rc1b, and PlsTsatB is derived as the loss PlsTsat2 at the second saturation temperature based on the GEN-INV loss characteristic Lc2 and the thermal resistance characteristic Rc1b. Furthermore, the second saturation temperature Tsat2 and the loss PlsTsat2 at the second saturation temperature based on the GEN-INV loss characteristic Lc2 and the thermal resistance characteristic Rc1b can also be described as the second saturation temperature Tsat2 and the loss PlsTsat2 at the second saturation temperature when the duty of the electric pump 22 is set to 40% [%.]

[0185] Similarly, the control device 50 also derives the second saturation temperature Tsat2 and the loss PlsTsat2 at the second saturation temperature based on the GEN-INV loss characteristic Lc2 and the thermal resistance characteristic Rc2b, as well as the second saturation temperature Tsat2 and the loss PlsTsat2 at the second saturation temperature based on the GEN-INV loss characteristic Lc2 and the thermal resistance characteristic Rc3b. Thus, the control device 50 is able to obtain the second saturation temperature Tsat2 and the loss PlsTsat2 at the second saturation temperature for each thermal resistance characteristic Rc, in other words, for each duty of the electric pump 22.

[0186] (4-3. The method for deriving the third saturation temperature and the loss at the third saturation temperature in the first application example)

[0187] Next, the method for deriving the third saturation temperature Tsat3 and the loss PlsTsat3 at the third saturation temperature in the first application example will be explained. Figure 6 This is a diagram illustrating an example of the method for deriving the third saturation temperature Tsat3 and the loss PlsTsat3 at the third saturation temperature in the first utilization example.

[0188] In the first example of use, such as Figure 6 As shown in the box marked with reference numeral 601, the control device 50 (e.g., loss characteristic derivation unit 51) derives the loss PlsT1c at a first temperature, for example, by referring to the loss diagram Mp1c. This first temperature loss PlsT1c is the VCU loss under the current I1 current, V1 voltage, and V2 voltage, and with the device temperature Tj set to 25 [°C]. Here, the loss diagram Mp1c represents information about the VCU loss corresponding to each combination of I1 current, V1 voltage, V2 voltage, and device temperature Tj, and is, for example, pre-stored in the storage unit 50b. Furthermore, the loss diagram Mp1c only needs to be able to determine the VCU loss information based on the I1 current, V1 voltage, V2 voltage, and device temperature Tj, and like the loss diagram Mp1, it can also be configured into multiple groups of data.

[0189] In addition, such as Figure 6 As shown in the box marked with reference numeral 601, similar to the loss PlsT1c at the first temperature, the control device 50 also derives the loss PlsT2c at the second temperature and the loss PlsT3c at the third temperature. Here, the loss PlsT2c at the second temperature can be, for example, set to the VCU loss under the current I1 current, V1 voltage, and V2 voltage, and with the device temperature Tj set to 75 [°C]. Similarly, the loss PlsT3c at the third temperature can be, for example, set to the VCU loss under the current I1 current, V1 voltage, and V2 voltage, and with the device temperature Tj set to 175 [°C].

[0190] Next, as Figure 6 As shown in the box marked with reference numeral 602, the control device 50 (e.g., loss characteristic derivation unit 51) derives a VCU loss characteristic Lc3 representing the VCU loss at each device temperature Tj based on the loss PlsT1c at the first temperature, the loss PlsT2c at the second temperature, and the loss PlsT3c at the third temperature. The VCU loss characteristic Lc3 is another example of the loss characteristic Lc, and like the loss characteristic Lc, it can be calculated geometrically, for example, based on the loss PlsT1c at the first temperature, the loss PlsT2c at the second temperature, and the loss PlsT3c at the third temperature.

[0191] Next, as Figure 6 As shown in the box marked with reference numeral 603, the control device 50 (e.g., flow output unit 52) ​​outputs the flow rate Fw of the electric pump 22 for each Duty, corresponding to the water temperature TWnow, with reference to the flow rate diagram Mp2. Figure 6 In the example shown, Fw1 is derived as the flow rate Fw when the Duty of the electric pump 22 is set to 40%, Fw2 is derived as the flow rate Fw when the Duty of the electric pump 22 is set to 60%, and Fw3 is derived as the flow rate Fw when the Duty of the electric pump 22 is set to 80%.

[0192] also, Figure 6 The processing shown in the box marked with reference numeral 603 in the attached figure is related to Figure 4 The process shown in the box marked with reference numeral 403 is the same as the process described in the figure. Therefore, the control device 50 only needs to execute... Figure 4 The process shown in the box marked with reference numeral 403 in the attached drawing can also be skipped. Figure 6 The treatment shown in the box marked with reference numeral 603 in the attached figure is not used as is. Figure 4 The processing result is shown in the box marked with reference numeral 403 in the attached figure.

[0193] Next, as Figure 6 As shown in the box marked with reference numeral 604, the control device 50 (e.g., thermal resistance output unit 53) outputs the thermal resistance Rt corresponding to each flow rate Fw based on the flow rate Fw output through the above-described process, referring to the thermal resistance diagram Mp3. Figure 6 In the example shown, Rt1 is derived from the thermal resistance Rt when the flow rate Fw is Fw1 (in other words, when the Duty is set to 40%); Rt2 is derived from the thermal resistance Rt when the flow rate Fw is Fw2 (in other words, when the Duty is set to 60%); and Rt3 is derived from the thermal resistance Rt when the flow rate Fw is Fw3 (in other words, when the Duty is set to 80%).

[0194] also, Figure 6 The processing shown in the box marked with reference numeral 604 in the attached figure is related to Figure 4 The process shown in the box marked with reference numeral 404 is the same as the process described in the figure. Therefore, the control device 50 only needs to execute... Figure 4 The process shown in the box marked with reference numeral 404 in the attached drawing can also be skipped. Figure 6 The treatment shown in the box marked with reference numeral 604 in the attached figure is not used as is. Figure 4 The processing result is shown in the box marked with reference numeral 404 in the attached figure.

[0195] Next, as Figure 6 As shown in the box marked with reference numeral 605, the control device 50 (e.g., thermal resistance characteristic derivation unit 54) derives the thermal resistance characteristic Rc corresponding to each thermal resistance Rt based on the thermal resistance Rt derived through the above-described process. Figure 6 In the example shown, the thermal resistance characteristic Rc1c is derived from the thermal resistance characteristic Rc when the thermal resistance Rt is Rt1 (in other words, when the duty is set to 40%). Furthermore, the thermal resistance characteristic Rc2c is derived from the thermal resistance characteristic Rc when the thermal resistance Rt is Rt2 (in other words, when the duty is set to 60%). And furthermore, the thermal resistance characteristic Rc3c is derived from the thermal resistance characteristic Rc when the thermal resistance Rt is Rt3 (in other words, when the duty is set to 80%).

[0196] For example, the thermal resistance characteristic Rc1c can be geometrically determined based on the first arrival temperature when the loss of the power conversion device 10 is set to the loss PlsT1c at the first temperature and the thermal resistance Rt is set to Rt1, the second arrival temperature when the loss of the power conversion device 10 is set to the loss PlsT2c at the second temperature and the thermal resistance Rt is set to Rt1, and the third arrival temperature when the loss of the power conversion device 10 is set to the loss PlsT3c at the third temperature and the thermal resistance Rt is set to Rt1. Furthermore, the first arrival temperature, the second arrival temperature, and the third arrival temperature can be determined, for example, by the above equation (1). Additionally, the thermal resistance characteristics Rc2c and Rc3c can also be determined in the same way as the thermal resistance characteristic Rc1c.

[0197] Next, as Figure 6 As shown in the box marked with reference numeral 606, the control device 50 (e.g., the loss derivation unit 55 at saturation temperature / saturation temperature) derives the third saturation temperature Tsat3 and the loss PlsTsat3 at the third saturation temperature for each thermal resistance characteristic Rc based on the VCU loss characteristic Lc3 and each thermal resistance characteristic Rc derived through the above processing.

[0198] For example, the third saturation temperature Tsat3 and the loss PlsTsat3 at the third saturation temperature, based on the VCU loss characteristic Lc3 and the thermal resistance characteristic Rc1c, can be calculated as the intersection of the VCU loss characteristic Lc3 and the thermal resistance characteristic Rc1c in a plane where the loss of the power conversion device 10 (in this case, the VCU loss) is taken on the horizontal axis and the device temperature Tj is taken on the vertical axis. Figure 6 In the example shown, TsatC is derived as the third saturation temperature Tsat3 based on the VCU loss characteristic Lc3 and the thermal resistance characteristic Rc1c, and PlsTsatC is derived as the loss PlsTsat3 at the third saturation temperature based on the VCU loss characteristic Lc3 and the thermal resistance characteristic Rc1c. Furthermore, the third saturation temperature Tsat3 and the loss PlsTsat3 at the third saturation temperature based on the VCU loss characteristic Lc3 and the thermal resistance characteristic Rc1c can also be described as the third saturation temperature Tsat3 and the loss PlsTsat3 at the third saturation temperature when the duty of the electric pump 22 is set to 40%.

[0199] Similarly, the control device 50 also derives the third saturation temperature Tsat3 and the loss PlsTsat3 at the third saturation temperature based on the VCU loss characteristic Lc3 and the thermal resistance characteristic Rc2c, as well as the third saturation temperature Tsat3 and the loss PlsTsat3 at the third saturation temperature based on the VCU loss characteristic Lc3 and the thermal resistance characteristic Rc3c. Thus, the control device 50 is able to obtain the third saturation temperature Tsat3 and the loss PlsTsat3 at the third saturation temperature for each thermal resistance characteristic Rc, in other words, for each duty of the electric pump 22.

[0200] (4-4. Finding the best duty)

[0201] In the first application example, the control device 50 finds the optimal duty of the electric pump 22 based on the losses at the first saturation temperature (PlsTsat1), the second saturation temperature (PlsTsat2), and the third saturation temperature (PlsTsat3) for each duty of the electric pump 22, as derived as described above. Here, the optimal duty is the duty of the electric pump 22 that minimizes the sum of the losses at the first saturation temperature (PlsTsat1), the second saturation temperature (PlsTsat2), the third saturation temperature (PlsTsat3), and the power consumption of the electric pump 22, when the V2 voltage is set to a predetermined value (e.g., the current V2 voltage).

[0202] Figure 7 This is a diagram illustrating an example of the optimal duty-finding method in the first utilization example. Figure 7 In the diagram, the horizontal axis represents the duty of electric pump 22, and the vertical axis represents the loss of vehicle 1 (in other words, the consumption of electricity).

[0203] When searching for the optimal duty, the control device 50, for example, outputs... Figure 7 The loss characteristics 701, 702, and 703 at the first saturation temperature are shown.

[0204] Here, the loss characteristic 701 at the first saturation temperature represents the loss PlsTsat1 at the first saturation temperature for each Duty of the electric pump 22 (i.e., the loss PlsTsat at the saturation temperature based on the MOT-INV loss), in other words, it represents the loss PlsTsat1 at the first saturation temperature corresponding to each Duty. For example, the loss characteristic 701 at the first saturation temperature can be determined based on the loss PlsTsat1 at the first saturation temperature for each Duty. Figure 4 The loss PlsTsat1 of the electric pump 22 at the first saturation temperature of each Duty obtained by the processing shown is calculated geometrically.

[0205] Furthermore, the loss characteristic 702 at the second saturation temperature represents the loss PlsTsat2 at the second saturation temperature for each Duty of the electric pump 22 (i.e., the loss PlsTsat at the saturation temperature based on the GEN-INV loss), in other words, it represents the loss PlsTsat2 at the second saturation temperature corresponding to each Duty. For example, the loss characteristic 702 at the second saturation temperature can be determined based on... Figure 5 The loss PlsTsat2 at the second saturation temperature of each Duty of the electric pump 22 obtained by the processing shown is calculated geometrically.

[0206] Furthermore, the loss characteristic 703 at the third saturation temperature represents the loss PlsTsat3 at the third saturation temperature for each Duty of the electric pump 22 (i.e., the loss PlsTsat at the saturation temperature based on the VCU loss), in other words, it represents the loss PlsTsat3 at the third saturation temperature corresponding to each Duty. For example, the loss characteristic 703 at the third saturation temperature can be determined based on the loss PlsTsat3 at the third saturation temperature for each Duty. Figure 6 The loss PlsTsat3 of the electric pump 22 at the third saturation temperature for each Duty obtained by the processing shown is calculated geometrically.

[0207] in addition, Figure 7 The EWP loss characteristic 704 shown represents the power consumption of the electric pump 22 for each Duty; in other words, it represents the power consumption of the electric pump 22 corresponding to each Duty. For example, information representing the EWP loss characteristic 704 is pre-stored in the storage unit 50b.

[0208] In the first application example, the control device 50 derives a total loss characteristic 710 based, for example, on the loss characteristics 701 at the first saturation temperature, 702 at the second saturation temperature, 703 at the third saturation temperature, and the EWP loss characteristic 704. Here, the total loss characteristic 710 represents the sum of the losses at the first saturation temperature (PlsTsat1), the second saturation temperature (PlsTsat2), the third saturation temperature (PlsTsat3), and the power consumption of the electric pump 22 for each duty. In other words, the total loss characteristic 710 represents the sum of the losses at the first saturation temperature (PlsTsat1), the second saturation temperature (PlsTsat2), the third saturation temperature (PlsTsat3), and the power consumption of the electric pump 22 for each duty.

[0209] Furthermore, the control device 50 searches for the optimal duty based on the total loss characteristic 710. More specifically, at this time, the control device 50 searches, for example, from the range of duties that can be used as actual drivers of the electric pump 22, i.e., the "duty applicable range," for the duty that minimizes the sum of the loss PlsTsat1 at the first saturation temperature, the loss PlsTsat2 at the second saturation temperature, the loss PlsTsat3 at the third saturation temperature, and the power consumption of the electric pump 22 as the optimal duty. Figure 7 In the example shown, Duty 80% is the optimal Duty. Furthermore, the applicable Duty range is preset by the manufacturer of vehicle 1, etc.

[0210] If the control device 50 finds the optimal duty, it drives the electric pump 22 at that optimal duty. Thus, the electric pump 22 can be appropriately controlled by taking into account the duty of MOT-INV loss, GEN-INV loss, VCU loss, and the power consumption of the electric pump 22, and the power consumption in the vehicle 1 can be reduced.

[0211] Furthermore, in the example described here, the control device 50 seeks the optimal duty based on the loss characteristics 701 at the first saturation temperature, the loss characteristics 702 at the second saturation temperature, the loss characteristics 703 at the third saturation temperature, and the EWP loss characteristics 704, but is not limited thereto.

[0212] For example, when vehicle 1 is operating in EV mode, or when vehicle 1 is a BEV (Battery Electric Vehicle) and does not have a second electric generator MG2, control device 50 can also find the optimal duty based on the loss characteristics 701 at the first saturation temperature, the loss characteristics 703 at the third saturation temperature, and the EWP loss characteristics 704. Furthermore, if the power consumption of electric pump 22 is sufficiently small compared to the loss of power conversion device 10, control device 50 may not use EWP loss characteristics 704 to find the optimal duty. Alternatively, control device 50 may use only any one of the loss characteristics 701 at the first saturation temperature, 702 at the second saturation temperature, and 703 at the third saturation temperature to find the optimal duty.

[0213] As explained above, in the first application example, the control device 50 outputs the flow rate Fw when the drive state of the electric pump 22 is set to a predetermined first state (e.g., Duty 40 [%)) and when it is set to a predetermined second state (e.g., Duty 60 [%)). Based on the output flow rate Fw, the control device 50 outputs the thermal resistance Rt when the pump is set to the first state and when it is set to the second state. Furthermore, the control device 50, based on the loss characteristics Lc of the power conversion device 10 (e.g., MOT-INV loss characteristics Lc1 or GEN-INV loss characteristics Lc2) and the corresponding thermal resistance characteristics Rc (e.g., thermal resistance characteristics Rc1a, Rc1b or thermal resistance characteristics Rc2a, Rc2b) for each of the derived thermal resistances Rt, derives each saturation temperature Tsat (e.g., first saturation temperature Tsat1 or second saturation temperature Tsat2) for the first state and the second state, as well as the loss PlsTsat at the saturation temperature (e.g., loss PlsTsat1 at the first saturation temperature or loss PlsTsat2 at the second saturation temperature), and controls the electric pump 22 based on the loss PlsTsat at each saturation temperature. Thus, the electric pump 22 can be controlled considering the loss PlsTsat at the saturation temperature for each flow rate Fw.

[0214] [5. Second Application Example]

[0215] Next, a second application example of the present invention will be described. This second application example is an example in which the control device 50 controls the power conversion device 10 based on the loss PlsTsat at the saturation temperature. In the second application example, as in the first application example, the control device 50 derives the first saturation temperature Tsat1, the second saturation temperature Tsat2, and the third saturation temperature Tsat3 as the saturation temperature Tsat, and derives the losses PlsTsat1, PlsTsat2, and PlsTsat3 at the first saturation temperature as the loss PlsTsat at the saturation temperature. Furthermore, the following description will focus on the differences from the description of the first application example, while the descriptions of the same parts as those in the first application example will be appropriately omitted.

[0216] (The second example uses the method of deriving the first saturation temperature and the loss at the first saturation temperature)

[0217] Figure 8 This is a diagram illustrating an example of the method for deriving the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature in the second utilization example.

[0218] In the second usage example, such as Figure 8As shown in the box marked with reference numeral 801 in the figure, the control device 50 (e.g., loss characteristic derivation unit 51) derives the loss PlsT1d at a first temperature, for example, with reference to the loss diagram Mp1a. This first temperature loss PlsT1d is calculated under the current MOT speed and MOT torque, with the V2 voltage set to a predetermined first voltage (in...). Figure 8 The example shown is the MOT-INV loss at 200 [V], with the device temperature Tj set to 25 [°C].

[0219] In addition, such as Figure 8 As shown in the box marked with reference numeral 801, similar to the loss PlsT1d at the first temperature, the control device 50 also derives the loss PlsT2d at the second temperature and the loss PlsT3d at the third temperature. Here, the loss PlsT2d at the second temperature can be, for example, set to the MOT-INV loss under the current MOT speed and MOT torque, with V2 voltage set to the first voltage and the equipment temperature Tj set to 75 [°C]. Similarly, the loss PlsT3d at the third temperature can be, for example, set to the MOT-INV loss under the current MOT speed and MOT torque, with V2 voltage set to the first voltage and the equipment temperature Tj set to 175 [°C].

[0220] Next, as Figure 8 As shown in the box marked with reference numeral 802, the control device 50 (e.g., loss characteristic derivation unit 51) derives the MOT-INV loss characteristic Lc1d into the MOT-INV loss characteristic Lc1 based on the loss PlsT1d at the first temperature, the loss PlsT2d at the second temperature, and the loss PlsT3d at the third temperature. The MOT-INV loss characteristic Lc1d can be obtained, for example, geometrically based on the loss PlsT1d at the first temperature, the loss PlsT2d at the second temperature, and the loss PlsT3d at the third temperature.

[0221] Next, as Figure 8 As shown in the box marked with reference numeral 801 in the attached figure, the control device 50 hereby derives the loss PlsT1e at the first temperature with reference to the loss diagram Mp1a. This loss PlsT1e at the first temperature is calculated under the current MOT speed and MOT torque, and with the V2 voltage set to a specified second voltage (in...). Figure 8 The example shown is the MOT-INV loss when the device temperature Tj is set to 25°C (350V).

[0222] In addition, such as Figure 8As shown in the box marked with reference numeral 801, similar to the loss PlsT1e at the first temperature, the control device 50 also derives the loss PlsT2e at the second temperature and the loss PlsT3e at the third temperature. Here, the loss PlsT2e at the second temperature can be, for example, set to the MOT-INV loss under the current MOT speed and MOT torque, with V2 voltage set to the second voltage and the equipment temperature Tj set to 75 [°C]. Similarly, the loss PlsT3e at the third temperature can be, for example, set to the MOT-INV loss under the current MOT speed and MOT torque, with V2 voltage set to the second voltage and the equipment temperature Tj set to 175 [°C].

[0223] Next, as Figure 8 As shown in the box marked with reference numeral 802, the control device 50 (e.g., loss characteristic derivation unit 51) derives the MOT-INV loss characteristic Lc1e into the MOT-INV loss characteristic Lc1 based on the loss PlsT1e at the first temperature, the loss PlsT2e at the second temperature, and the loss PlsT3e at the third temperature. The MOT-INV loss characteristic Lc1e can be calculated geometrically, for example, based on the loss PlsT1e at the first temperature, the loss PlsT2e at the second temperature, and the loss PlsT3e at the third temperature.

[0224] Next, as Figure 8 As shown in the box marked with reference numeral 801 in the attached figure, the control device 50 hereby derives the loss PlsT1f at the first temperature with reference to the loss diagram Mp1a. This loss PlsT1f at the first temperature is calculated under the current MOT speed and MOT torque, and with the V2 voltage set to a specified third voltage (in...). Figure 8 The example shown is the MOT-INV loss when the device temperature Tj is set to 25°C (500V).

[0225] In addition, such as Figure 8 As shown in the box marked with reference numeral 801, similar to the loss PlsT1f at the first temperature, the control device 50 also derives the loss PlsT2f at the second temperature and the loss PlsT3f at the third temperature. Here, the loss PlsT2f at the second temperature can be, for example, set to the MOT-INV loss under the current MOT speed and MOT torque, with V2 voltage set to the third voltage and the equipment temperature Tj set to 75 [°C]. Similarly, the loss PlsT3f at the third temperature can be, for example, set to the MOT-INV loss under the current MOT speed and MOT torque, with V2 voltage set to the third voltage and the equipment temperature Tj set to 175 [°C].

[0226] Next, as Figure 8As shown in the box marked with reference numeral 802, the control device 50 (e.g., loss characteristic derivation unit 51) derives the MOT-INV loss characteristic Lc1f into the MOT-INV loss characteristic Lc1 based on the loss PlsT1f at the first temperature, the loss PlsT2f at the second temperature, and the loss PlsT3f at the third temperature. The MOT-INV loss characteristic Lc1f can be obtained, for example, geometrically based on the loss PlsT1f at the first temperature, the loss PlsT2f at the second temperature, and the loss PlsT3f at the third temperature.

[0227] Thus, in the second application example, the control device 50 derives the MOT-INV loss characteristic Lc1 when the V2 voltage is set to multiple different voltage values; in other words, it derives the MOT-INV loss characteristic Lc1 for each V2 voltage. Furthermore, based on the intersection of each MOT-INV loss characteristic Lc1 with the thermal resistance characteristic Rc when the duty of the electric pump 22 is set to a predetermined value (e.g., the current duty) (e.g., the intersection of a plane with the horizontal axis representing the loss of the power conversion device 10 and the vertical axis representing the device temperature Tj), the control device 50 derives the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature for each V2 voltage.

[0228] Similarly, the control device 50 also derives the second saturation temperature Tsat2 and the loss PlsTsat2 at the second saturation temperature for each V2 voltage, as well as the third saturation temperature Tsat3 and the loss PlsTsat3 at the third saturation temperature for each V2 voltage.

[0229] (5-2. Finding the optimal V2 voltage)

[0230] In the second application example, the control device 50 searches for the optimal V2 voltage based on the losses at the first saturation temperature (PlsTsat1), the second saturation temperature (PlsTsat2), and the third saturation temperature (PlsTsat3) of each V2 voltage derived as described above. Here, the optimal V2 voltage is the voltage value that minimizes the sum of the losses at the first saturation temperature (PlsTsat1), the second saturation temperature (PlsTsat2), the third saturation temperature (PlsTsat3), and the power consumption of the electric pump 22, when the duty of the electric pump 22 is set to a predetermined value (e.g., the current duty).

[0231] Figure 9 This is a diagram illustrating an example of the method for finding the optimal V2 voltage in the second utilization example. Figure 9 In the diagram, the horizontal axis represents the voltage V2, and the vertical axis represents the loss of vehicle 1 (in other words, the consumption of electricity).

[0232] When searching for the optimal V2 voltage, the control device 50, for example, derives... Figure 9 The loss characteristics 901, 902, and 903 at the first saturation temperature are shown.

[0233] Here, the loss characteristic 901 at the first saturation temperature represents the loss PlsTsat1 at the first saturation temperature for each V2 voltage (i.e., the loss PlsTsat at the saturation temperature based on the MOT-INV loss), in other words, it represents the loss PlsTsat1 at the first saturation temperature corresponding to the voltage value of each V2 voltage. For example, the loss characteristic 901 at the first saturation temperature can be determined based on... Figure 8 The loss PlsTsat1 at the first saturation temperature of each V2 voltage obtained by the processing shown is calculated geometrically.

[0234] Furthermore, the loss characteristic 902 at the second saturation temperature represents the loss PlsTsat2 at the second saturation temperature for each V2 voltage (i.e., the loss PlsTsat at the saturation temperature based on the GEN-INV loss), in other words, it represents the loss PlsTsat2 at the second saturation temperature corresponding to the voltage value of each V2 voltage. For example, the loss characteristic 902 at the second saturation temperature can be obtained geometrically based on the loss PlsTsat2 at the second saturation temperature for each V2 voltage.

[0235] Furthermore, the loss characteristic 903 at the third saturation temperature represents the loss PlsTsat3 at the third saturation temperature for each V2 voltage (i.e., the loss PlsTsat at the saturation temperature based on the VCU loss), in other words, it represents the loss PlsTsat3 at the third saturation temperature corresponding to the voltage value of each V2 voltage. For example, the loss characteristic 903 at the third saturation temperature can be obtained geometrically based on the loss PlsTsat3 at the third saturation temperature for each V2 voltage.

[0236] in addition, Figure 9 The EWP loss characteristic 904 shown represents the power consumption of the electric pump 22 for each V2 voltage; in other words, it represents the power consumption of the electric pump 22 corresponding to the voltage value of each V2 voltage. For example, information representing the EWP loss characteristic 904 is pre-stored in the storage unit 50b.

[0237] In the second application example, the control device 50 derives a total loss characteristic 910 based, for example, on the loss characteristics 901 at the first saturation temperature, 902 at the second saturation temperature, 903 at the third saturation temperature, and the EWP loss characteristic 904. Here, the total loss characteristic 910 represents the sum of the losses at the first saturation temperature (PlsTsat1), the second saturation temperature (PlsTsat2), the third saturation temperature (PlsTsat3), and the power consumption of the electric pump 22 for each V2 voltage. In other words, the total loss characteristic 910 represents the sum of the losses at the first saturation temperature (PlsTsat1), the second saturation temperature (PlsTsat2), the third saturation temperature (PlsTsat3), and the power consumption of the electric pump 22, corresponding to the voltage values ​​of each V2 voltage.

[0238] Furthermore, the control device 50 searches for the optimal V2 voltage based on the total loss characteristic 910. More specifically, at this time, the control device 50 searches, for example, from the range of voltage values ​​that can be used as V2 voltage, i.e., the "applicable range of V2 voltage," for the voltage value that minimizes the sum of the losses at the first saturation temperature PlsTsat1, the second saturation temperature PlsTsat2, the third saturation temperature PlsTsat3, and the power consumption of the electric pump 22 as the optimal V2 voltage. Figure 9 In the example shown, 420V is selected as the optimal V2 voltage. Furthermore, the applicable range of V2 voltage is preset by the manufacturer of vehicle 1, etc.

[0239] If the control device 50 finds the optimal V2 voltage in this way, it controls the power conversion device 10 to make the actual V2 voltage the optimal V2 voltage. As a result, by taking into account the MOT-INV loss, GEN-INV loss, VCU loss, and the V2 voltage that consumes power from the electric pump 22, the first electric generator MG1 and the like can be operated appropriately, thereby reducing the power consumption in the vehicle 1.

[0240] Furthermore, in the example described here, the control device 50 finds the optimal V2 voltage based on the loss characteristics 901 at the first saturation temperature, the loss characteristics 902 at the second saturation temperature, the loss characteristics 903 at the third saturation temperature, and the EWP loss characteristics 904, but is not limited thereto.

[0241] For example, when vehicle 1 is operating in EV mode, or when vehicle 1 is a BEV and does not have a second electric generator MG2, control device 50 can also find the optimal V2 voltage based on the loss characteristics 901 at the first saturation temperature, the loss characteristics 903 at the third saturation temperature, and the EWP loss characteristics 904. Furthermore, if the power consumption of electric pump 22 is sufficiently small compared to the losses of power conversion device 10, control device 50 may not use EWP loss characteristics 904 to find the optimal V2 voltage. Alternatively, control device 50 may use only any one of the loss characteristics 901 at the first saturation temperature, the loss characteristics 902 at the second saturation temperature, and the loss characteristics 903 at the third saturation temperature to find the optimal V2 voltage.

[0242] As explained above, in the second application example, the control device 50 derives various loss characteristics Lc (e.g., MOT-INV loss characteristics Lc1d, Lc1e) for the case where the V2 voltage is set to a predetermined first voltage value (e.g., 200 [V]) and the case where it is set to a predetermined second voltage value (e.g., 350 [V]). Based on the various loss characteristics Lc and the thermal resistance characteristic Rc, it derives various saturation temperatures Tsat and losses PlsTsat at the saturation temperatures for the case where the voltage is set to the first voltage value and the case where the voltage is set to the second voltage value. The power conversion device 10 is then controlled based on the losses PlsTsat at each saturation temperature (e.g., loss characteristic 901 at the first saturation temperature). Thus, the power conversion device 10 can be controlled by taking into account the losses PlsTsat at the saturation temperature of each V2 voltage.

[0243] [6. Third example of application]

[0244] Next, a third application example of the present invention will be described. This third application example is an example in which the control device 50 (e.g., vehicle control unit 56) determines the state of vehicle 1 based on the saturation temperature Tsat. More specifically, in the third application example, the control device 50 determines the state of vehicle 1 based on whether the equipment temperature sensor 36 is abnormal, based on the equipment temperature Tj detected by the equipment temperature sensor 36 and the saturation temperature Tsat. Furthermore, in the third application example, unless otherwise specified, the saturation temperature Tsat is the saturation temperature Tsat under the current operating conditions when the first electric generator MG1, etc., is running and the power conversion device 10 is cooled under the current cooling conditions (e.g., the duty of the electric pump 22).

[0245] Under normal conditions, it is assumed that the equipment temperature Tj detected by the equipment temperature sensor 36 will eventually stabilize near the saturation temperature Tsat. Therefore, if the equipment temperature Tj detected by the equipment temperature sensor 36 deviates from the saturation temperature Tsat for a certain period of time, the equipment temperature sensor 36 may be malfunctioning (e.g., failing).

[0246] Therefore, in the third application example, the control device 50 determines that the equipment temperature sensor 36 is abnormal if the temperature difference (hereinafter also referred to as "temperature difference ΔT") between the equipment temperature Tj detected by the equipment temperature sensor 36 and the saturation temperature Tsat, or in other words, the value obtained by subtracting the saturation temperature Tsat from the equipment temperature Tj, is above a predetermined threshold for a predetermined period Tmx. In other words, the control device 50 determines that the equipment temperature sensor 36 is normal if the temperature difference ΔT is less than the threshold, or if the temperature difference ΔT is above the threshold but only momentarily. Thus, the control device 50 can accurately determine whether the equipment temperature sensor 36 is abnormal based on the saturation temperature Tsat. Furthermore, the aforementioned threshold and predetermined period Tmx are preset by the manufacturer of vehicle 1, etc. In addition, from the viewpoint of suppressing false detections of abnormalities in the equipment temperature sensor 36, it is preferable that the control device 50 determines whether the equipment temperature sensor 36 is abnormal only when the temperature change of the power conversion device 10 is relatively small, such as when vehicle 1 is parked or under low load.

[0247] Figure 10 This is a diagram illustrating an example of an anomaly detection method for the device temperature sensor 36 in the third application example. Figure 10 In (A), the vertical axis represents the equipment temperature Tj detected by the equipment temperature sensor 36, and the horizontal axis represents the period. Additionally, in Figure 10 In (B) of the diagram, the vertical axis represents the temperature difference ΔT, and the horizontal axis represents the period.

[0248] like Figure 10 As shown in (B) in the third application example, as a threshold related to the temperature difference ΔT, a high temperature fault determination threshold ThH and a low temperature fault determination threshold ThL are set (where the low temperature fault determination threshold ThL < the high temperature fault determination threshold ThH).

[0249] As an example, the device temperature Tj detected by device temperature sensor 36 is as follows: Figure 10 The solid line 1010 shown in (A) shifts as indicated, and the temperature difference ΔT is as shown in the figure. Figure 10The solid line 1011 shown in (B) moves as indicated. In this case, during the period from period t10 to period t11, the temperature difference ΔT is less than the high temperature fault determination threshold ThH and greater than the low temperature fault determination threshold ThL, so the control device 50 determines that the equipment temperature sensor 36 is normal.

[0250] Furthermore, in this case, starting from period t11, the temperature difference ΔT is above the high-temperature fault determination threshold ThH, and this state continues even after a predetermined period Tmx has elapsed from period t11 to period t12. Thus, when the temperature difference ΔT remains above the high-temperature fault determination threshold ThH for the predetermined period Tmx, the control device 50 determines that a "high-temperature fault" has occurred in the equipment temperature sensor 36. Here, a high-temperature fault refers to an abnormality where the equipment temperature sensor 36 detects a temperature higher than normal as the equipment temperature Tj.

[0251] As another example, the device temperature Tj detected by device temperature sensor 36 is as follows: Figure 10 The dashed line 1020 in (A) shifts as shown, and the temperature difference ΔT is as follows: Figure 10 The movement is as shown by the dashed line 1021 in (B). In this case, during the period from period t10 to period t11, the temperature difference ΔT is less than the high temperature fault determination threshold ThH and greater than the low temperature fault determination threshold ThL. Therefore, the control device 50 determines that the equipment temperature sensor 36 is normal.

[0252] Furthermore, in this case, starting from period t11, the temperature difference ΔT is below the low-temperature fault determination threshold ThL, and even after a predetermined period Tmx has elapsed from period t11 to period t12, the temperature difference ΔT remains below the low-temperature fault determination threshold ThL. Thus, if the temperature difference ΔT remains below the low-temperature fault determination threshold ThL for the predetermined period Tmx, the control device 50 determines that a "low-temperature fault" has occurred in the equipment temperature sensor 36. Here, a low-temperature fault refers to an abnormality where the equipment temperature sensor 36 detects a temperature lower than normal as the equipment temperature Tj.

[0253] As explained above, in the third application example, the control device 50 determines whether the equipment temperature sensor 36 is malfunctioning based on the equipment temperature Tj and saturation temperature Tsat detected by the equipment temperature sensor 36. Therefore, it is possible to determine whether the equipment temperature sensor 36 is malfunctioning with good accuracy.

[0254] Furthermore, in the third application example, if the control device 50 determines that the equipment temperature sensor 36 has malfunctioned, it may, for example, report the malfunction to the occupants of vehicle 1 via a notification device (e.g., a display) provided with vehicle 1. This would prompt the occupants of vehicle 1 to undergo an inspection by vehicle 1.

[0255] (A variation of the third application example)

[0256] Next, a modified example of the third application example will be described. The modified example described below involves setting multiple device temperature sensors 36, such as a first device temperature sensor 36a, a second device temperature sensor 36b, and a third device temperature sensor 36c, and the control device 50 determines whether the water temperature sensor 35 is malfunctioning based on the device temperature Tj and saturation temperature Tsat detected by them respectively. Furthermore, the following will focus on the differences from the examples described above, while appropriately omitting or simplifying the descriptions of the parts that are the same as those described above.

[0257] In this modified example, the device temperature Tj detected by the first device temperature sensor 36a is also referred to as the "first device temperature," and the temperature difference between the first device temperature and the saturation temperature Tsat is also referred to as the "temperature difference ΔTa." Furthermore, the device temperature Tj detected by the second device temperature sensor 36b is also referred to as the "second device temperature," and the temperature difference between the second device temperature and the saturation temperature Tsat is also referred to as the "temperature difference ΔTb." Finally, the device temperature Tj detected by the third device temperature sensor 36c is also referred to as the "third device temperature," and the temperature difference between the third device temperature and the saturation temperature Tsat is also referred to as the "temperature difference ΔTc."

[0258] Furthermore, in this modified example, an anomaly in the temperature of the first device refers to, for example, a temperature difference ΔTa that is above the high-temperature fault determination threshold ThH or below the low-temperature fault determination threshold ThL. An anomaly in the temperature of the second device refers to, for example, a temperature difference ΔTb that is above the high-temperature fault determination threshold ThH or below the low-temperature fault determination threshold ThL. An anomaly in the temperature of the third device refers to, for example, a temperature difference ΔTc that is above the high-temperature fault determination threshold ThH or below the low-temperature fault determination threshold ThL.

[0259] Figure 11 This is a diagram illustrating a judgment example in a modified example of the third utilization example, where the control device 50 makes a judgment corresponding to the temperature state of each device. For example... Figure 11As shown in Table 1100, in this modified example, if only one of the three equipment temperatures—the first equipment temperature, the second equipment temperature, and the third equipment temperature—is abnormal, and this state continues for a specified period Tmx, the control device 50 determines that the equipment temperature sensor that detected the equipment temperature is abnormal.

[0260] In addition, such as Figure 11 As shown in Table 1100, in situations described as "State B-1", "State B-2", and "State B-3", where two of the three device temperatures (first, second, and third) are abnormal and the remaining device temperature is normal, the control device 50 does not determine that the temperature sensors 36a, 36b, and 36c are malfunctioning. Instead, it determines that the water temperature sensor 35 is malfunctioning. This is because it is considered that the probability of two of the three device temperature sensors (first, second, and third) malfunctioning simultaneously is low.

[0261] And, as Figure 11 As shown in Table 1100, in a "State C" where the temperatures of the first, second, and third devices are all abnormal, and this state persists for a specified period Tmx, the control device 50 determines that the water temperature sensor 35 has malfunctioned. That is, in the case of "State C," compared to the probability of malfunctions in the temperature sensors 36a, 36b, and 36c, the probability of an abnormality in the water temperature TW value used to derive the saturation temperature Tsat, i.e., the probability of a malfunction in the water temperature sensor 35, is higher. Therefore, in the case of "State C," by determining that the water temperature sensor 35 has malfunctioned, the control device 50 can suppress false detections of malfunctions in the temperature sensors 36a, 36b, and 36c, and can detect malfunctions in the water temperature sensor 35 with high accuracy.

[0262] Figure 12 This is a diagram illustrating an example of an anomaly detection method for a water temperature sensor in a modified example of the third utilization example. Figure 12 In (A), the vertical axis represents the temperature difference ΔTa, and the horizontal axis represents the period. Figure 12 In (B) of the diagram, the vertical axis represents the temperature difference ΔTb, and the horizontal axis represents the period. Figure 12 In (C), the vertical axis represents the temperature difference ΔTc, and the horizontal axis represents the period.

[0263] exist Figure 12In the example shown, starting from period t21, only the temperature difference ΔTa is above the high-temperature fault determination threshold ThH, so the control device 50 determines the state of vehicle 1 as "state A-1". Afterwards, starting from period t22 before the specified period Tmx from period t21, the temperature difference ΔTb is also above the high-temperature fault determination threshold ThH, so the control device 50 determines the state of vehicle 1 as "state B-1".

[0264] Furthermore, starting from period t23 after period t22, the temperature difference ΔTc remains above the high-temperature fault determination threshold ThH, therefore the control device 50 classifies the vehicle 1 as "State C". Subsequently, even after period t24, which is a predetermined period Tmx from period t23, the temperature differences ΔTa, ΔTb, and ΔTc remain above the high-temperature fault determination threshold ThH. Thus, since the state (i.e., "State C") where the temperature differences ΔTa, ΔTb, and ΔTc remain above the high-temperature fault determination threshold ThH persists for the predetermined period Tmx, the control device 50 determines that the water temperature sensor 35 has malfunctioned.

[0265] Furthermore, in the example described here, when the vehicle 1 is in "State C", the control device 50 determines that the water temperature sensor 35 has malfunctioned, but it is not limited to this. For example, when the vehicle 1 is in "State B-1", "State B-2" or "State B-3", the control device 50 can also determine that the water temperature sensor 35 has malfunctioned.

[0266] Furthermore, the example described here uses three device temperature sensors 36: a first device temperature sensor 36a, a second device temperature sensor 36b, and a third device temperature sensor 36c. However, this is not the only possibility. For example, two device temperature sensors 36 could be used, and if the device temperatures corresponding to each of them are abnormal, the control device 50 would determine that the water temperature sensor 35 has malfunctioned. Alternatively, four or more device temperature sensors 36 could be used, and if the device temperatures corresponding to each of them are abnormal, or if two or more predetermined numbers of device temperatures are abnormal, the control device 50 would determine that the water temperature sensor 35 has malfunctioned.

[0267] As explained above, in this modified example, the control device 50 determines whether the water temperature sensor 35 is malfunctioning based on the device temperature Tj and saturation temperature Tsat detected by the respective device temperature sensors. Therefore, it is possible to determine with high accuracy whether the water temperature sensor 35 is malfunctioning.

[0268] [7. Fourth Application Example]

[0269] Next, a fourth application example of the present invention will be described. This fourth application example is an example in which the control device 50 (e.g., vehicle control unit 56) determines the load state of the vehicle 1 based on the saturation temperature Tsat, and controls the vehicle 1 based on the determination result.

[0270] Figure 13 This is a diagram illustrating an example of the vehicle control method in the fourth application example. For example... Figure 13 As shown, in the fourth application example, a cooling priority threshold and a heating priority threshold are set as thresholds based on the equipment temperature Tj detected by the equipment temperature sensor 36. For example, the control device 50 sets the temperature obtained by adding a predetermined value greater than 0 to the equipment temperature Tj as the cooling priority threshold, and sets the temperature obtained by subtracting the predetermined value greater than 0 from the equipment temperature Tj as the heating priority threshold. Here, the predetermined value is preset by the manufacturer of vehicle 1, etc.

[0271] like Figure 13 As shown, in the fourth application example, when the saturation temperature Tsat is lower than the cooling priority threshold but higher than the heating priority threshold, i.e., when vehicle 1 is under medium load, the control device 50 determines the state of vehicle 1 as "mode α" and executes efficiency-priority control. In efficiency-priority control, the control device 50 finds the optimal duty to control the electric pump 22, for example, as described in the first application example, or finds the optimal V2 voltage to control the power conversion device 10, thereby optimizing the efficiency in vehicle 1.

[0272] Furthermore, when the saturation temperature Tsat is above the cooling priority threshold, i.e., when vehicle 1 is under high load, the control device 50 determines the state of vehicle 1 as "mode β" and executes cooling priority control. In cooling priority control, the control device 50 suppresses the temperature rise of the power conversion device 10 by increasing the duty of the electric pump 22 compared to the current duty. At this time, the control device 50 may also set the duty of the electric pump 22 to the maximum value within the applicable duty range.

[0273] Furthermore, when the saturation temperature Tsat is below the heating priority threshold, i.e., when vehicle 1 is under low load, control device 50 determines the state of vehicle 1 as "mode γ" and executes heating priority control. In heating priority control, control device 50 promotes the temperature rise of power conversion device 10 by reducing the duty of electric pump 22 compared to the current duty. At this time, control device 50 may also set the duty of electric pump 22 to the minimum value within the applicable duty range.

[0274] As explained above, in the fourth application example, the control device 50 determines the load state of the vehicle 1 based on the equipment temperature Tj and saturation temperature Tsat detected by the equipment temperature sensor 36, and controls the vehicle 1 based on the determination result, thereby enabling the vehicle 1 to be appropriately controlled by taking into account the load state in the vehicle 1.

[0275] Furthermore, while the above embodiments illustrate an example of implementing the control device of the present invention via a control device 50 mounted on vehicle 1, the invention is not limited thereto. For example, the control device of the present invention may also be implemented via a server capable of communicating with the control device 50. In this case, for example, the processing unit implemented by the server's CPU or the like can perform the various processes of the control device 50. Additionally, the control device of the present invention may also be implemented through cooperation between the control device 50 and a server; for example, a portion of the processing of the control device 50 may also be executed by the server.

[0276] Furthermore, the control method described in the above embodiments can be implemented by executing a pre-prepared program using a computer (in other words, a processor). This program (control program) is stored in a computer-readable storage medium and executed by reading it from the storage medium. Alternatively, this program can be provided in the form of a non-volatile (non-transitory) storage medium such as a flash memory, or via a network such as the Internet. The computer executing this program can be included in vehicle 1, or it can be included in an external device (e.g., a server) capable of communicating with vehicle 1.

[0277] The above description illustrates one embodiment of the present invention, but the present invention is not limited to this embodiment. Obviously, those skilled in the art will be able to conceive of various modifications or alterations within the scope of the technical solution described, and it should be understood that these modifications and alterations also fall within the technical scope of the present invention.

[0278] For example, in the above embodiments, the mobile body in the present invention is a hybrid electric vehicle, i.e., vehicle 1, but it is not limited thereto. For example, the mobile body in the present invention can be a battery electric vehicle (BEV), an electric vertical takeoff and landing (eVTOL), or a drone (unmanned aerial vehicle).

[0279] The following are at least described in this specification and other documents. Furthermore, although the corresponding components in the above embodiments are shown in parentheses, the present invention is not limited thereto.

[0280] (1) A control method executed by a computer (control device 50) controlling a mobile body (vehicle 1), the mobile body comprising: an electric generator (first electric generator MG1, second electric generator MG2); a power conversion device (power conversion device 10, first inverter 11, second inverter 12, voltage conversion device 13) receiving and transmitting power from the electric generator; and a cooling device (cooling device 20) cooling the power conversion device, wherein,

[0281] The computer performs the following processing:

[0282] Based on the operating conditions of the electric generator, the loss characteristics (loss characteristics Lc) are derived, which represent the losses of the power conversion device at each temperature when the electric generator is operating under these operating conditions (step Sp3).

[0283] Based on the cooling conditions of the cooling device for cooling the power conversion device, the thermal resistance (thermal resistance Rt) of the power conversion device under the cooling conditions is derived (step Sp5).

[0284] Based on the loss characteristics and the thermal resistance, the thermal resistance characteristic (thermal resistance characteristic Rc) is derived, which represents the temperature at which each loss of the power conversion device reaches its destination (step Sp6).

[0285] Based on the loss characteristics and the thermal resistance characteristics, the saturation temperature (saturation temperature Tsat) and the loss at the saturation temperature (loss at the saturation temperature PlsTsat) are derived. The saturation temperature is the temperature reached by the power conversion device when the electric generator is operated under the operating conditions and the power conversion device is cooled under the cooling conditions. The loss at the saturation temperature is the loss of the power conversion device when it reaches the saturation temperature (step Sp7).

[0286] Based on the saturation temperature and / or the loss at the saturation temperature, control the moving body (step Sp8).

[0287] According to (1), the saturation temperature and the loss at saturation temperature can be derived when the electric generator is operated under specified operating conditions and the power conversion device is cooled under specified cooling conditions. Therefore, it is possible to control the moving body taking into account the saturation temperature and / or the loss at saturation temperature. Furthermore, this can help improve the energy efficiency of the moving body.

[0288] (2) According to the control method described in (1), wherein,

[0289] The computer derives the loss of the power conversion device corresponding to the intersection point (intersection point CP) of the loss characteristic and the thermal resistance characteristic in a plane with one axis taking the loss of the power conversion device and the other axis taking the temperature of the power conversion device as the loss at the saturation temperature, and derives the temperature of the power conversion device corresponding to the intersection point as the saturation temperature.

[0290] According to (2), the saturation temperature and the loss at the saturation temperature can be calculated with good accuracy through simple calculations.

[0291] (3) The control method according to (1) or (2), wherein,

[0292] The computer derives the loss characteristics based on the rotational speed (MOT speed, GEN speed) and output torque (MOT torque, GEN torque) of the electric generator as the operating conditions, and the voltage value (V2 voltage) of the power supplied between the electric generator and the power conversion device.

[0293] According to (3), it is possible to derive the loss characteristics that take into account the rotational speed and output torque of the electric generator and the voltage value of the power transmitted between the electric generator and the power conversion device.

[0294] (4) According to the control method described in (3), wherein,

[0295] The computer performs the following processing:

[0296] The loss characteristics are derived for the case where the voltage value is set to a predetermined first voltage value and for the case where the voltage value is set to a predetermined second voltage value different from the first voltage value.

[0297] Based on the aforementioned loss characteristics and thermal resistance characteristics, the losses at each of the saturation temperatures and the saturation temperatures are derived, assuming the voltage is set to the first value and the voltage is set to the second value.

[0298] The power conversion device is controlled based on the losses at each of the aforementioned saturation temperatures.

[0299] According to (4), the power conversion device can be controlled by taking into account the loss at the saturation temperature of each voltage value of the power received between the electric generator and the power conversion device.

[0300] (5) The control method according to (1) or (2), wherein,

[0301] The cooling device includes: a cooling circuit (cooling circuit 21) for circulating cooling water; and an electric pump (electric pump 22) for pressurizing and delivering the cooling water in the cooling circuit.

[0302] The moving body is equipped with a water temperature sensor (water temperature sensor 35) to detect the temperature of the cooling water.

[0303] The computer performs the following processing:

[0304] Based on the temperature of the cooling water (water temperature TW) detected by the water temperature sensor as the cooling condition and the driving state (Duty) of the electric pump, the flow rate (flow rate Fw) of the cooling water pumped by the electric pump per unit time is derived (step Sp4).

[0305] The thermal resistance is derived based on the flow rate.

[0306] According to (5), even without installing a flow sensor to detect the flow rate of cooling water pumped by an electric pump, the thermal resistance of the power conversion device can be appropriately derived.

[0307] (6) According to the control method described in (5), wherein,

[0308] The computer performs the following processing:

[0309] The flow rates are derived for the case where the electric pump is driven in a predetermined first state and for the case where the electric pump is driven in a predetermined second state different from the first state.

[0310] Based on the respective flow rates, the respective thermal resistances for the first state and the second state are derived.

[0311] Based on the loss characteristics and the thermal resistance characteristics corresponding to each of the respective thermal resistances, the losses at each of the saturation temperatures and the saturation temperatures are derived for the first state and the second state.

[0312] The electric pump is controlled based on the losses at each of the aforementioned saturation temperatures.

[0313] According to (6), the electric pump can be controlled by taking into account the loss at the saturation temperature of each flow of cooling water pumped by the electric pump.

[0314] (7) The control method according to (1) or (2), wherein,

[0315] The mobile body is equipped with a device temperature sensor (device temperature sensor 36) for detecting the temperature of the power conversion device.

[0316] The computer determines whether the device temperature sensor is malfunctioning based on the temperature of the power conversion device detected by the device temperature sensor and the saturation temperature.

[0317] According to (7), the temperature sensor of the device that detects the temperature of the power conversion device is abnormal and can be accurately determined.

[0318] (8) The control method according to (1) or (2), wherein,

[0319] The cooling device has a cooling circuit (cooling circuit 21) for circulating cooling water.

[0320] The mobile body includes: a water temperature sensor (water temperature sensor 35) for detecting the temperature of the cooling water; and multiple device temperature sensors (first device temperature sensor 36a, second device temperature sensor 36b, and third device temperature sensor 36c) for detecting the temperature of the power conversion device.

[0321] The computer determines whether the water temperature sensor is malfunctioning based on the temperature of the power conversion device detected by the temperature sensors of each of the devices and the saturation temperature.

[0322] According to (8), it is possible to accurately determine whether the water temperature sensor that detects the temperature of the cooling water circulating in the cooling circuit is malfunctioning.

[0323] (9) The control method according to (1) or (2), wherein,

[0324] The mobile body is equipped with a device temperature sensor (device temperature sensor 36) for detecting the temperature of the power conversion device.

[0325] The computer determines the load status of the mobile body based on the temperature of the power conversion device detected by the device's temperature sensor and the saturation temperature, and controls the mobile body based on the determination result.

[0326] According to (9), the load status of the mobile body can be taken into account to appropriately control the mobile body.

[0327] (10) The control method according to (1) or (2), wherein,

[0328] The mobile body is equipped with multiple electric generators (first electric generator MG1, second electric generator MG2) as the electric generators.

[0329] The computer, for each of the electric generators, derives the saturation temperature and the loss at the saturation temperature.

[0330] According to (10), even when the mobile body has multiple electric generators, it is possible to control the mobile body by taking into account the saturation temperature and / or the loss at the saturation temperature corresponding to each electric generator.

[0331] (11) A control device (control device 50) for controlling a moving body (vehicle 1), the moving body comprising: an electric generator (first electric generator MG1, second electric generator MG2); a power conversion device (power conversion device 10, first inverter 11, second inverter 12, voltage conversion device 13) for receiving and transmitting power from the electric generator; and a cooling device (cooling device 20) for cooling the power conversion device, wherein,

[0332] The control device includes:

[0333] The loss characteristic derivation unit (loss characteristic derivation unit 51) derives a loss characteristic (loss characteristic Lc) based on the operating conditions of the electric generator. This loss characteristic represents the loss of the power conversion device at each temperature when the electric generator is operating under these operating conditions.

[0334] The thermal resistance output section (thermal resistance output section 53) outputs the thermal resistance (thermal resistance Rt) of the power conversion device when the power conversion device is cooled under the cooling conditions of the cooling device.

[0335] The thermal resistance characteristic derivation unit (thermal resistance characteristic derivation unit 54) derives a thermal resistance characteristic (thermal resistance characteristic Rc) based on the loss characteristic derived by the loss characteristic derivation unit and the thermal resistance derived by the thermal resistance derivation unit. This thermal resistance characteristic represents the temperature at which each loss of the power conversion device reaches its destination.

[0336] The saturation temperature / loss derivation unit (saturation temperature / loss derivation unit 55) derives the saturation temperature (saturation temperature Tsat) and the loss at saturation temperature (loss at saturation temperature PlsTsat) based on the loss characteristics and the thermal resistance characteristics derived by the thermal resistance characteristic derivation unit. The saturation temperature is the temperature reached by the power conversion device when the electric generator is operated under the stated operating conditions and the power conversion device is cooled under the stated cooling conditions. The loss at saturation temperature is the loss of the power conversion device when it reaches that saturation temperature.

[0337] The moving body control unit (vehicle control unit 56) controls the moving body based on the saturation temperature and / or the loss at the saturation temperature derived by the loss derivation unit at the saturation temperature / saturation temperature.

[0338] According to (11), the saturation temperature and the loss at saturation temperature can be derived when the electric generator is operated under specified operating conditions and the power conversion device is cooled under specified cooling conditions. Therefore, it is possible to control the moving body taking into account the saturation temperature and / or the loss at saturation temperature. Furthermore, this can help improve the energy efficiency of the moving body.

[0339] (12) A control program that causes a computer (control device 50) controlling a mobile body (vehicle 1) to perform predetermined processing, the mobile body comprising: an electric generator (first electric generator MG1, second electric generator MG2); a power conversion device (power conversion device 10, first inverter 11, second inverter 12, voltage conversion device 13) that receives and transmits power from the electric generator; and a cooling device (cooling device 20) that cools the power conversion device, wherein,

[0340] The control program causes the computer to perform the following processes:

[0341] Based on the operating conditions of the electric generator, the loss characteristics (loss characteristics Lc) are derived, which represent the losses of the power conversion device at each temperature when the electric generator is operating under these operating conditions (step Sp3).

[0342] Based on the cooling conditions of the cooling device for cooling the power conversion device, the thermal resistance (thermal resistance Rt) of the power conversion device under the cooling conditions is derived (step Sp5).

[0343] Based on the loss characteristics and the thermal resistance, the thermal resistance characteristic (thermal resistance characteristic Rc) is derived, which represents the temperature at which each loss of the power conversion device reaches its destination (step Sp6).

[0344] Based on the loss characteristics and the thermal resistance characteristics, the saturation temperature (saturation temperature Tsat) and the loss at the saturation temperature (loss at the saturation temperature PlsTsat) are derived. The saturation temperature is the temperature reached by the power conversion device when the electric generator is operated under the operating conditions and the power conversion device is cooled under the cooling conditions. The loss at the saturation temperature is the loss of the power conversion device when it reaches the saturation temperature (step Sp7).

[0345] Based on the saturation temperature and / or the loss at the saturation temperature, control the moving body (step Sp8).

[0346] According to (12), the saturation temperature and the loss at saturation temperature can be derived when the electric generator is operated under specified operating conditions and the power conversion device is cooled under specified cooling conditions. Therefore, it is possible to control the mobile body taking into account the saturation temperature and / or the loss at saturation temperature. Furthermore, this can help improve the energy efficiency of the mobile body.

Claims

1. A control method executed by a computer controlling a mobile body, the mobile body comprising: an electric generator; a power conversion device that receives and exchanges power with the electric generator; and a cooling device that cools the power conversion device, wherein... The computer performs the following processing: Based on the operating conditions of the electric generator, loss characteristics are derived, which represent the losses of the power conversion device at each temperature when the electric generator is operating under these conditions. Based on the cooling conditions of the cooling device for cooling the power conversion device, the thermal resistance of the power conversion device under these cooling conditions is derived. Based on the aforementioned loss characteristics and thermal resistance, a thermal resistance characteristic is derived, which represents the temperature at which each loss of the power conversion device reaches its destination. Based on the aforementioned loss characteristics and thermal resistance characteristics, the saturation temperature and the loss at saturation temperature are derived. The saturation temperature is the temperature reached by the power conversion device when the electric generator is operating under the aforementioned operating conditions and the power conversion device is cooled under the aforementioned cooling conditions. The loss at saturation temperature is the loss of the power conversion device at that saturation temperature. The moving body is controlled based on the saturation temperature and / or the loss at the saturation temperature.

2. The control method according to claim 1, wherein, The computer derives the loss of the power conversion device corresponding to the intersection of the loss characteristic and the thermal resistance characteristic in a plane with one axis taking the loss of the power conversion device and the other axis taking the temperature of the power conversion device as the loss at the saturation temperature, and derives the temperature of the power conversion device corresponding to the intersection point as the saturation temperature.

3. The control method according to claim 1 or 2, wherein, The computer derives the loss characteristics based on the rotational speed and output torque of the electric generator as operating conditions, and the voltage value of the power supplied between the electric generator and the power conversion device.

4. The control method according to claim 3, wherein, The computer performs the following processing: The loss characteristics are derived for the case where the voltage value is set to a predetermined first voltage value and for the case where the voltage value is set to a predetermined second voltage value different from the first voltage value. Based on the aforementioned loss characteristics and thermal resistance characteristics, the losses at each of the saturation temperatures and the saturation temperatures are derived, assuming the voltage is set to the first value and the voltage is set to the second value. The power conversion device is controlled based on the losses at each of the aforementioned saturation temperatures.

5. The control method according to claim 1 or 2, wherein, The cooling device includes: a cooling circuit for circulating cooling water; and an electric pump for pressurizing and delivering the cooling water in the cooling circuit. The mobile body is equipped with a water temperature sensor to detect the temperature of the cooling water. The computer performs the following processing: Based on the temperature of the cooling water detected by the water temperature sensor and the driving state of the electric pump, which are the cooling conditions, the flow rate of the cooling water pumped by the electric pump per unit time is derived. The thermal resistance is derived based on the flow rate.

6. The control method according to claim 5, wherein, The computer performs the following processing: The flow rates are derived for the case where the electric pump is driven in a predetermined first state and for the case where the electric pump is driven in a predetermined second state different from the first state. Based on the respective flow rates, the respective thermal resistances for the first state and the second state are derived. Based on the loss characteristics and the thermal resistance characteristics corresponding to each of the respective thermal resistances, the losses at each of the saturation temperatures and the saturation temperatures are derived for the first state and the second state. The electric pump is controlled based on the losses at each of the aforementioned saturation temperatures.

7. The control method according to claim 1 or 2, wherein, The mobile body is equipped with a temperature sensor to detect the temperature of the power conversion device. The computer determines whether the device temperature sensor is malfunctioning based on the temperature of the power conversion device detected by the device temperature sensor and the saturation temperature.

8. The control method according to claim 1 or 2, wherein, The cooling device has a cooling circuit for circulating cooling water. The mobile body includes: a water temperature sensor for detecting the temperature of the cooling water; and multiple device temperature sensors for detecting the temperature of the power conversion device. The computer determines whether the water temperature sensor is malfunctioning based on the temperature of the power conversion device detected by the temperature sensors of each of the devices and the saturation temperature.

9. The control method according to claim 1 or 2, wherein, The mobile body is equipped with a temperature sensor to detect the temperature of the power conversion device. The computer determines the load status of the mobile body based on the temperature of the power conversion device detected by the device's temperature sensor and the saturation temperature, and controls the mobile body based on the determination result.

10. The control method according to claim 1 or 2, wherein, The mobile body is equipped with multiple electric generators to serve as the electric generators. The computer, for each of the electric generators, derives the saturation temperature and the loss at the saturation temperature.

11. A control device for controlling a mobile body, the mobile body comprising: an electric generator; a power conversion device for receiving and transmitting power from the electric generator; and a cooling device for cooling the power conversion device, wherein... The control device includes: The loss characteristic derivation section derives loss characteristics based on the operating conditions of the electric generator, which represent the losses of the power conversion device at each temperature when the electric generator is operating under those operating conditions. The thermal resistance output section outputs the thermal resistance of the power conversion device under the cooling conditions of the cooling device cooling the power conversion device. A thermal resistance characteristic derivation section derives a thermal resistance characteristic based on the loss characteristic derived by the loss characteristic derivation section and the thermal resistance derived by the thermal resistance derivation section, the thermal resistance characteristic representing the arrival temperature of each loss of the power conversion device. A loss derivation section at saturation temperature / saturation temperature, based on the loss characteristics and the thermal resistance characteristics derived by the thermal resistance characteristic derivation section, derives the saturation temperature and the loss at saturation temperature, where the saturation temperature is the temperature reached by the power conversion device when the electric generator is operated under the stated operating conditions and the power conversion device is cooled under the stated cooling conditions, and the loss at saturation temperature is the loss of the power conversion device when it reaches that saturation temperature; and The moving body control unit controls the moving body based on the saturation temperature and / or the loss at the saturation temperature derived by the loss derivation unit at the saturation temperature / saturation temperature.

12. A storage medium storing a control program that causes a computer controlling a mobile body to perform predetermined processing, the mobile body comprising: an electric generator; a power conversion device that receives and exchanges power with the electric generator; and a cooling device that cools the power conversion device, wherein... The control program causes the computer to perform the following processes: Based on the operating conditions of the electric generator, loss characteristics are derived, which represent the losses of the power conversion device at each temperature when the electric generator is operating under these conditions. Based on the cooling conditions of the cooling device for cooling the power conversion device, the thermal resistance of the power conversion device under these cooling conditions is derived. Based on the aforementioned loss characteristics and thermal resistance, a thermal resistance characteristic is derived, which represents the temperature at which each loss of the power conversion device reaches its destination. Based on the aforementioned loss characteristics and thermal resistance characteristics, the saturation temperature and the loss at saturation temperature are derived. The saturation temperature is the temperature reached by the power conversion device when the electric generator is operating under the aforementioned operating conditions and the power conversion device is cooled under the aforementioned cooling conditions. The loss at saturation temperature is the loss of the power conversion device at that saturation temperature. The moving body is controlled based on the saturation temperature and / or the loss at the saturation temperature.

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