Control method, control device, and control program

Abstract

To appropriately derive a saturation temperature and a loss at the saturation temperature of a power conversion device.SOLUTION: A control device 50 includes: a loss characteristic derivation unit 51 that derives a loss characteristic Lc representing a loss of a power conversion device 10 for each temperature on the basis of operating conditions of a first motor generator MG1; a thermal resistance derivation unit 53 that derives a thermal resistance Rt of the power conversion device 10 on the basis of cooling conditions by a cooling device 20; a thermal resistance characteristic derivation unit 54 that derives a thermal resistance characteristic Rc of the power conversion device 10 on the basis of the loss characteristic Lc and the thermal resistance Rt; a saturation temperature and loss-at-saturation temperature derivation unit 55 that derives a saturation temperature Tsat and a loss at the saturation temperature PlsTsat of the power conversion device 10 on the basis of the loss characteristic Lc and the thermal resistance characteristic Rc; and a vehicle control unit 56 that controls a vehicle 1 on the basis of the saturation temperature Tsat and the loss at the saturation temperature PlsTsat.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a control method, a control device, and a control program.

Background Art

[0002] In recent years, as specific measures against global climate change, efforts have been actively made to realize a low-carbon society or a decarbonized society. In mobile bodies such as automobiles, reduction of CO2 emissions and improvement of energy efficiency are required, and research and development on electrification technologies for electrifying their drive sources have been carried out.

[0003] In Patent Document 1 below, the loss power for each motor temperature when driving a motor at a predicted operating point, the operating speeds of the fan and the pump for each motor temperature, and the power consumption of the fan and the pump when operating at that operating speed are calculated respectively, the sum of the motor loss power, the fan power consumption, and the pump power consumption is obtained for each motor temperature, and a technique is disclosed in which the motor temperature at which the sum is minimized is set as the target motor temperature.

[0004] Also, in Patent Document 2 below, a technique is disclosed in which the loss that can occur in an inverter is calculated from the required output of a motor, and the discharge amount of a pump and the supply amount of cooling air to a fan are controlled according to the calculation result.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the above-mentioned conventional technology, the technique for deriving the saturation temperature, which is the temperature reached by the power converter when the motor generator is operated under predetermined operating conditions and the power converter that exchanges power with the motor generator is cooled under predetermined cooling conditions, and the saturation temperature loss, which is the loss of the power converter at that saturation temperature, has not been sufficiently considered, and there was room for improvement in this respect.

[0007] This invention provides a control method, a control device, and a control program that can appropriately derive the saturation temperature and the loss at saturation temperature of a power converter. Ultimately, this contributes to improving energy efficiency. [Means for solving the problem]

[0008] One aspect of the present invention is, A control method performed by a computer that controls a mobile body comprising a motor generator, a power converter that exchanges power with the motor generator, and a cooling device that cools the power converter, The aforementioned computer, Based on the operating conditions of the motor generator, the loss characteristics representing the temperature-dependent losses of the power converter when the motor generator is operated under those operating conditions are derived. Based on the cooling conditions of the power converter by the cooling device, the thermal resistance of the power converter when the power converter is cooled under those cooling conditions is derived. Based on the loss characteristics and the thermal resistance, a thermal resistance characteristic representing the temperature reached for each loss in the power converter is derived. Based on the loss characteristics and the thermal resistance characteristics, the saturation temperature, which is the temperature reached by the power converter when the motor generator is operated under the operating conditions and the power converter is cooled under the cooling conditions, and the loss at saturation temperature, which is the loss of the power converter at that saturation temperature, are derived. Based on the saturation temperature and / or the loss at the saturation temperature, the moving body is controlled. This is a control method for performing processing.

[0009] Another aspect of the present invention is, A control device for controlling a mobile body comprising a motor generator, a power converter that exchanges power with the motor generator, and a cooling device that cools the power converter, A loss characteristic derivation unit that derives loss characteristics representing the temperature-dependent losses of the power converter when the motor generator is operated under the operating conditions of the motor generator, based on the operating conditions of the motor generator, A thermal resistance derivation unit that derives the thermal resistance of the power converter when the power converter is cooled under the cooling conditions of the cooling device, based on the cooling conditions of the power converter by the cooling device, A thermal resistance characteristic derivation unit derives a thermal resistance characteristic representing the temperature reached for each loss in the power converter, based on the loss characteristics derived by the loss characteristic derivation unit and the thermal resistance derived by the thermal resistance derivation unit. A saturation temperature / saturation temperature loss derivation unit derives, based on the loss characteristics and the thermal resistance characteristics derived by the thermal resistance characteristic derivation unit, the saturation temperature which is the temperature reached by the power converter when the motor generator is operated under the operating conditions and the power converter is cooled under the cooling conditions, and the saturation temperature loss which is the loss of the power converter when it is at the saturation temperature. Based on the saturation temperature and / or the loss at saturation temperature derived by the saturation temperature / loss at saturation temperature derivation unit, a mobile body control unit controls the mobile body, It is a control device equipped with [a specific feature].

[0010] Another aspect of the present invention is, A control program that causes a computer controlling a mobile body comprising a motor generator, a power converter that exchanges power with the motor generator, and a cooling device that cools the power converter to perform a predetermined process, To the aforementioned computer, Based on the operating conditions of the motor generator, the loss characteristics representing the temperature-dependent losses of the power converter when the motor generator is operated under those operating conditions are derived. Based on the cooling conditions of the power conversion device by the cooling device, the thermal resistance of the power conversion device when the power conversion device is cooled under the cooling conditions is derived. Based on the loss characteristics and the thermal resistance, a thermal resistance characteristic representing the temperature reached for each loss of the power conversion device is derived. Based on the loss characteristics and the thermal resistance characteristics, the motor generator is operated under the operating conditions, and the saturation temperature, which is the temperature reached by the power conversion device when the power conversion device is cooled under the cooling conditions, and the loss at the saturation temperature, which is the loss of the power conversion device when it is at the saturation temperature, are derived. Based on the saturation temperature and / or the loss at the saturation temperature, the moving body is controlled. A control program that causes the processing to be executed.

Advantages of the Invention

[0011] According to the present invention, it is possible to provide a control method, a control device, and a control program capable of appropriately deriving the saturation temperature and the loss at the saturation temperature of a power conversion device.

Brief Description of the Drawings

[0012] [Figure 1] FIG. 1 is a diagram showing an example of the schematic configuration of the vehicle 1 of the present embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of the functional configuration of the control device 50. [Figure 3] FIG. 3 is a flowchart showing an example of the processing executed by the control device 50. <000008x>FIG. 4 is a diagram showing an example of a method for deriving the first saturation temperature Tsat1 and the first loss at the saturation temperature PlsTsat1 in the first usage example. [Figure 5] FIG. 5 is a diagram showing an example of a method for deriving the second saturation temperature Tsat2 and the second loss at the saturation temperature PlsTsat2 in the first usage example. [Figure 6]FIG. 6 is a diagram showing an example of a method for deriving the third saturation temperature Tsat3 and the loss PlsTsat3 at the third saturation temperature in the first application example. [Figure 7] FIG. 7 is a diagram showing an example of a method for searching for the optimum duty in the first application example. [Figure 8] FIG. 8 is a diagram showing an example of a method for deriving the first saturation temperature Tsat1 and the loss PlsTsat1 at the first saturation temperature in the second application example. [Figure 9] FIG. 9 is a diagram showing an example of a method for searching for the optimum V2 voltage in the second application example. [Figure 10] FIG. 10 is a diagram showing an example of a method for detecting an abnormality of the device temperature sensor 36 in the third application example. [Figure 11] FIG. 11 is a diagram showing an example of a determination by the control device 50 according to the state of each device temperature in a modified example of the third application example. [Figure 12] FIG. 12 is a diagram showing an example of a method for detecting an abnormality of the water temperature sensor in a modified example of the third application example. [Figure 13] FIG. 13 is a diagram showing an example of a vehicle control method in the fourth application example.

MODE FOR CARRYING OUT THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The following embodiment is an example in the case where the moving body in the present invention is a vehicle. In the following, the same or similar elements are denoted by the same or similar reference numerals, and the description thereof may be omitted or simplified as appropriate.

[0014] [1. Schematic Configuration of Vehicle] FIG. 1 is a diagram showing an example of the schematic configuration of the vehicle 1 of the present embodiment. The vehicle 1 of the present embodiment shown in FIG. 1 is a hybrid electric vehicle, and includes a battery BAT, an engine ENG, a first motor generator MG1, a second motor generator MG2, a power conversion device 10, a cooling device 20, a vehicle sensor 30, and a control device 50.

[0015] A battery (BAT) is a rechargeable secondary battery. For example, a battery (BAT) has multiple energy storage cells connected in series or in series-parallel and is configured to output high voltages of 100 to 400 [V]. Examples of energy storage cells that can be used in a battery (BAT) include lithium-ion batteries and nickel-metal hydride batteries.

[0016] The engine ENG is an internal combustion engine that outputs power generated by burning a fuel such as gasoline, diesel fuel, or an ethanol mixture. The engine ENG is mechanically connected to the second motor generator MG2, which will be described later, and can also be mechanically connected to the drive wheels DW of the vehicle 1 via a clutch CL. For example, a friction clutch can be used as the clutch CL. When the clutch CL is engaged (in other words, fastened), the power output from the engine ENG is transmitted to the second motor generator MG2 and the drive wheels DW, and when the clutch CL is disengaged (in other words, open), the power is transmitted only to the second motor generator MG2.

[0017] The first motor generator MG1 is a motor generator (a so-called "traction motor") that is mechanically connected to the drive wheel DW and used as the drive source for vehicle 1. For the first motor generator MG1, for example, an AC motor (more specifically, a three-phase AC motor) can be used.

[0018] Furthermore, the first motor generator MG1 is electrically connected to the battery BAT and the second motor generator MG2 via a power conversion device 10, which will be described later. The first motor generator MG1 operates as an electric motor and outputs power when power is supplied from at least one of the battery BAT and the second motor generator MG2. The power output from the first motor generator MG1 is transmitted to the drive wheels DW. In other words, the vehicle 1 moves when power from at least one of the engine ENG and the first motor generator MG1 is transmitted to the drive wheels DW.

[0019] Furthermore, the first motor generator MG1 may also perform regenerative operation as a generator when the vehicle 1 is braking, generating electricity (so-called "regenerative power generation"). The electricity generated by the regenerative operation of the first motor generator MG1 (hereinafter also referred to as "regenerative power") can be supplied to the battery BAT via the power converter 10. This allows the battery BAT to be charged with regenerative power.

[0020] The second motor generator MG2 is a motor generator that is mechanically connected to the engine ENG and used as a generator to generate electricity using the power of the engine ENG. The second motor generator MG2 is also electrically connected to the battery BAT and the first motor generator MG1 via the power converter 10. The electricity generated by the second motor generator MG2 is supplied to at least one of the battery BAT and the first motor generator MG1 via the power converter 10. This allows the electricity generated by the second motor generator MG2 to charge the battery BAT or drive the first motor generator MG1.

[0021] The power converter 10 is a device (a so-called "power control unit") that converts the input power and outputs the converted power. In this embodiment, the power converter 10 is electrically connected to the first motor generator MG1, the second motor generator MG2, and the battery BAT, and converts the power exchanged between them.

[0022] More specifically, the power conversion device 10 is configured by housing, for example, a first inverter 11, a second inverter 12, and a voltage conversion device 13 in a single housing. Here, the first inverter 11 and the second inverter 12 are devices equipped with multiple switching elements that convert DC to AC and AC to DC by switching these elements. As the switching elements of the first inverter 11 and the second inverter 12, for example, MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) and IGBTs (Insulated Gate Bipolar Transistors) can be used.

[0023] Furthermore, the voltage converter 13 is a device (also known as a "voltage control unit") that converts the input voltage to a predetermined voltage and outputs the converted voltage. For example, a DC / DC converter can be used as the voltage converter 13. In this embodiment, the voltage converter 13 converts the voltage of the power exchanged between the first motor generator MG1 or the second motor generator MG2 and the battery BAT.

[0024] For example, in vehicle 1, when supplying power from battery BAT to first motor generator MG1, the output voltage of battery BAT is boosted by voltage converter 13, then converted to AC power by first inverter 11, and that AC power is supplied to first motor generator MG1.

[0025] Furthermore, in vehicle 1, when regenerative power generation is performed by the first motor generator MG1, the AC power as regenerative power generated from the first motor generator MG1 is converted into DC power by the first inverter 11, and then the DC power is stepped down by the voltage converter 13, and the stepped-down DC power is supplied to the battery BAT.

[0026] Furthermore, in vehicle 1, when power is generated by the second motor generator MG2, the AC power generated from the second motor generator MG2 is converted to DC power by the second inverter 12, and then supplied to the first motor generator MG1 via the first inverter 11, or supplied to the battery BAT via the voltage converter 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 motor generator MG1. The voltage converter 13 steps down the DC power received from the second inverter 12 and outputs the stepped-down DC power to the battery BAT.

[0027] The cooling device 20 is a device that cools the power conversion device 10. For example, the cooling device 20 is a water-cooled cooling device that includes a cooling circuit 21 through which cooling water (e.g., LLC (Long Life Coolant)) as a refrigerant circulates, and an electric pump 22 that pressurizes and pumps the cooling water in the cooling circuit 21.

[0028] The cooling circuit 21 performs heat exchange between the cooling water and the power conversion device 10 (for example, a housing containing the first inverter 11, the second inverter 12, and the voltage converter 13), as well as heat exchange between the cooling water and the outside air. The cooling circuit 21 can be realized, for example, by a water jacket or radiator provided inside the housing of the power conversion device 10.

[0029] The electric pump 22 is an electric pump driven by power from the battery BAT or power generated by the second motor generator MG2, and is controlled, for example, by the control device 50 described later. For example, PWM (Pulse Width Modulation) control is used to control the electric pump 22 by the control device 50.

[0030] The vehicle sensor 30 is a sensor that acquires various information about the vehicle 1 and outputs the acquired information to the control device 50, which will be described later. The information acquired by the vehicle sensor 30 is used for the control of the vehicle 1 by the control device 50 (hereinafter also simply referred to as "vehicle control").

[0031] The vehicle sensor 30 includes, for example, a first current / voltage sensor 31, a second current / voltage sensor 32, a MOT rotation speed sensor 33, a GEN rotation speed sensor 34, a water temperature sensor 35, and a device temperature sensor 36.

[0032] 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 exchanged between the battery BAT and the voltage converter 13. The first current / voltage sensor 31 can be realized, for example, by a current sensor and a voltage sensor installed in the power line connecting the battery BAT and the voltage converter 13.

[0033] 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 exchanged between the voltage converter 13 and the first inverter 11 and / or the second inverter 12. The second current / voltage sensor 32 can be realized, for example, by a current sensor and a voltage sensor provided in the power line connecting the voltage converter 13 and the first inverter 11 and the second inverter 12.

[0034] The MOT rotation speed sensor 33 is a sensor that detects the rotation speed of the first motor generator MG1 (hereinafter also referred to as "MOT rotation speed"). For example, the MOT rotation speed sensor 33 can be realized by a resolver provided on the first motor generator MG1.

[0035] The GEN rotation speed sensor 34 is a sensor that detects the rotation speed of the second motor generator MG2 (hereinafter also referred to as "GEN rotation speed"). For example, the GEN rotation speed sensor 34 can be implemented by a resolver provided on the second motor generator MG2.

[0036] The water temperature sensor 35 is a sensor that detects the temperature of the cooling water circulating in the cooling circuit 21 (hereinafter also referred to as "water temperature TW"). For example, the water temperature sensor 35 can be implemented by a temperature sensor provided in the cooling circuit 21.

[0037] The device temperature sensor 36 is a sensor that detects the temperature of the power converter 10 (hereinafter also referred to as "device temperature Tj"). For example, the device temperature sensor 36 can be realized by a temperature sensor provided on a semiconductor chip that integrates the switching elements of the power converter 10.

[0038] Although not shown in the diagrams and detailed explanations, the vehicle sensor 30 may include, for example, a vehicle speed sensor for detecting the driving speed of the vehicle 1 (hereinafter also referred to as "vehicle speed"), an AP sensor for detecting the amount of operation on the accelerator pedal of the vehicle 1 (hereinafter also referred to as "AP (accelerator position)").

[0039] The control device 50 is a computer that provides overall control for the vehicle 1, and is composed of, for example, a processor 50a that performs various calculations, a storage unit 50b that has a non-transient 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 data between the inside and outside of the control device 50. For example, the control device 50 can be realized by a single ECU (Electronic Control Unit) or by multiple ECUs working together.

[0040] The control device 50 controls, for example, the output of the engine ENG, the output of the first motor generator MG1 and / or the second motor generator MG2 via the power converter 10, the state of the clutch CL, and the electric pump 22 based on information acquired by the vehicle sensor 30.

[0041] As an example, the control device 50 controls the driving mode of the vehicle 1. Here, the driving modes of the vehicle 1 may include, for example, an EV (Electric Vehicle) driving mode, a hybrid driving mode, and an engine driving mode.

[0042] The EV driving mode is a driving mode in which only the power from the battery BAT is supplied to the first motor generator MG1, and the vehicle 1 is driven by the power output by the first motor generator MG1 according to that 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 motor generator MG2), and drives the first motor generator MG1 by supplying only the power from the battery BAT to the first motor generator MG1, thereby driving the vehicle 1.

[0043] The hybrid driving mode is a driving mode in which at least the power generated by the second motor generator MG2 is supplied to the first motor generator MG1, and the vehicle 1 is driven primarily by the power output by the first motor generator MG1 in accordance with that power. More specifically, in the hybrid driving mode, the control device 50 disengages the clutch CL while causing the second motor generator MG2 to generate power using the power of the engine ENG. The control device 50 then drives the first motor generator MG1 by supplying the power generated by the second motor generator MG2 to the first motor generator MG1, thereby driving the vehicle 1. In addition, in the hybrid driving mode, the control device 50 may, as appropriate, also supply power from the battery BAT to the first motor generator MG1.

[0044] The engine driving mode is a driving mode in which the vehicle 1 is driven primarily by the power output by the engine ENG. More specifically, in the engine driving mode, the control device 50 operates the engine ENG with the clutch CL engaged. In addition, in the engine driving mode, the control device 50 may, as appropriate, supply power from the battery BAT to the first motor generator MG1 and use the power output by the first motor generator MG1 to drive the vehicle 1.

[0045] As another example, the control device 50 derives the saturation temperature Tsat and the loss at saturation temperature PlsTsat, which will be described later, and controls the vehicle 1 based on the saturation temperature Tsat and / or the loss at saturation temperature PlsTsat. Below, a specific example of the control performed by the control device 50 in this case will be described in detail.

[0046] [2. Functional configuration of the control device] Figure 2 is a block diagram showing an example of the functional configuration of the control device 50. As shown in Figure 2, 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 saturation temperature / saturation temperature loss derivation unit 55, and a vehicle control unit 56. Each of the functional units of the loss characteristic derivation unit 51, the flow rate derivation unit 52, the thermal resistance derivation unit 53, the thermal resistance characteristic derivation unit 54, the saturation temperature / saturation temperature loss derivation unit 55, and the vehicle control unit 56 can be realized, for example, by the processor 50a executing a program stored in the storage unit 50b, or by the I / F unit 50c.

[0047] The loss characteristic derivation unit 51 derives loss characteristics Lc, which represent the loss of the power converter 10 at each temperature (i.e., device temperature Tj) when the first motor generator MG1 is operated under the operating conditions of the first motor generator MG1, based on the operating conditions of the first motor generator MG1, and passes the processing results to the thermal resistance characteristic derivation unit 54 and the saturation temperature / saturation temperature loss derivation unit 55.

[0048] One example of losses in the power converter 10 is the loss of the first inverter 11 (hereinafter also referred to as "MOT-INV loss"). Another example of losses in the power converter 10 is the loss of the second inverter 12 (hereinafter also referred to as "GEN-INV loss"). Furthermore, another example of losses in the power converter 10 is the loss of the voltage converter 13 (hereinafter also referred to as "VCU (Voltage Control Unit) loss"). In other words, the losses in the power converter 10 may include MOT-INV loss, GEN-INV loss, and VCU loss.

[0049] Furthermore, the operating conditions of the first motor generator MG1 may include the MOT rotational speed, the output torque of the first motor generator MG1 (hereinafter also referred to as "MOT torque"), and the V2 voltage.

[0050] For example, the loss characteristic derivation unit 51 receives information indicating the current MOT rotational speed, MOT torque, and V2 voltage. The control device 50 can obtain information indicating the current MOT rotational speed from the MOT rotational speed sensor 33, and information indicating the current V2 voltage from the second current / voltage sensor 32. It can also derive (i.e., obtain) information indicating the current MOT torque based on the current MOT rotational speed and V2 voltage. The loss characteristic derivation unit 51 then derives the loss characteristic Lc when the first motor generator MG1 is operated at the current MOT rotational speed, MOT torque, and V2 voltage.

[0051] More specifically, for example, the memory unit 50b pre-stores a loss map Mp1, which is information showing the loss of the power converter 10 according to each combination of MOT rotation speed, MOT torque, V2 voltage, and device temperature Tj. Here, the loss map Mp1 only needs to contain information that allows the loss of the power converter 10 to be identified from the MOT rotation speed, MOT torque, V2 voltage, and device temperature Tj, and may be configured as a group of multiple maps (in other words, tables) in the data. If the loss map Mp1 is configured as a group of multiple maps, the loss map Mp1 may include, for example, a map showing the loss of the power converter 10 corresponding to the combination of MOT rotation speed, MOT torque, and V2 voltage at a first temperature T1, as described later, and a map showing the loss of the power converter 10 corresponding to the combination of MOT rotation speed, MOT torque, and V2 voltage at a second temperature T2, as described later.

[0052] Then, as shown in the frame labeled 51a in Figure 2, the loss characteristic derivation unit 51 derives the first temperature loss PlsT1, which is the loss of the power converter 10 when the device temperature Tj is set to a predetermined first temperature T1, at the current MOT rotational speed, MOT torque, and V2 voltage (in other words, the current operating conditions of the first motor generator MG1), by referring to the loss map Mp1. In this case, the loss characteristic derivation unit 51 only needs to derive the first temperature loss PlsT1 as the loss corresponding to the combination of the current MOT rotational speed, MOT torque, and V2 voltage and the first temperature T1 as the device temperature Tj, in the loss map Mp1. Here, the first temperature T1 is a temperature predetermined by the manufacturer of the vehicle 1, and can be, for example, 25°C, which is one of the temperatures that the device temperature Tj can take when the vehicle 1 is running.

[0053] Furthermore, as shown in the frame labeled 51b in Figure 2, the loss characteristic derivation unit 51 also derives the second temperature loss PlsT2, which is the loss of the power converter 10 when the current MOT rotational speed, MOT torque, and V2 voltage are set to a predetermined second temperature T2, in the same way as the first temperature loss PlsT1. That is, the loss characteristic derivation unit 51 only needs to derive the second temperature loss PlsT2 in the loss map Mp1, which corresponds to the loss corresponding to the combination of the current MOT rotational speed, MOT torque, and V2 voltage and the second temperature T2 as the device temperature Tj. Here, the second temperature T2 is a temperature predetermined by the manufacturer of the vehicle 1, and is different from the first temperature T1. For example, the second temperature T2 can be 175°C, which is one of the temperatures that the device temperature Tj can take when the vehicle 1 is running, and is higher than the first temperature T1 (for example, 25°C).

[0054] The loss characteristic derivation unit 51 then derives the loss characteristic Lc based on the first temperature loss PlsT1 and the second temperature loss PlsT2. The loss characteristic Lc can be determined geometrically from, for example, the first temperature loss PlsT1 and the second temperature loss PlsT2. More specifically, as shown in the frame labeled 51c in Figure 2, the loss characteristic derivation unit 51 can derive the loss characteristic Lc as a line segment passing through coordinate point P1(PlsT1,T1) and coordinate point P2(PlsT2,T2) on a plane where the horizontal axis represents the loss of the power converter 10 and the vertical axis represents the device temperature Tj.

[0055] In this example, the loss characteristic derivation unit 51 derives the loss characteristic Lc based on two losses corresponding to different device temperatures Tj, namely the first temperature loss PlsT1 and the second temperature loss PlsT2. However, it is not limited to this configuration. For example, the loss characteristic derivation unit 51 may derive the loss characteristic Lc based on three or more losses corresponding to different device temperatures Tj.

[0056] Furthermore, although the loss characteristic derivation unit 51 is configured here to derive the loss characteristic Lc based on the current operating conditions of the first motor generator MG1, it is not limited to this. For example, as will be described later, the loss characteristic derivation unit 51 may be configured to derive the loss characteristic Lc when the first motor generator MG1 is operated under predetermined operating conditions (e.g., a predetermined V2 voltage).

[0057] The flow rate output unit 52 derives the flow rate Fw of the cooling water pumped per unit time by the electric pump 22 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, and passes the processing result to the thermal resistance output unit 53. The driving state of the electric pump 22 can be, for example, the duty cycle of the PWM-controlled electric pump 22 (hereinafter also simply referred to as "Duty"). The flow rate Fw is an example of the cooling conditions of the power converter 10 by the cooling device 20.

[0058] For example, the flow rate output unit 52 receives information indicating the current water temperature TW (hereinafter also referred to as "water temperature TWnow") and the Duty, which represents the current operating state of the electric pump 22. The flow rate output unit 52 then derives the current flow rate Fw based on the water temperature TWnow and the current Duty.

[0059] To explain in more detail, for example, the memory unit 50b has a flow rate map Mp2 pre-stored, which is information indicating the flow rate Fw corresponding to each combination of Duty and water temperature TW. Then, as shown in the frame labeled 52a in Figure 2, the flow rate derivation unit 52 derives the flow rate Fw corresponding to the current combination of water temperature TW (i.e., water temperature TWnow) and Duty by referring to the flow rate map Mp2. In the example shown in Figure 2, since the current Duty is X[%], Fw1 corresponding to the combination of water temperature TWnow and DutyX[%] is derived as the flow rate Fw.

[0060] In this example, the flow rate output unit 52 is configured to output the flow rate Fw based on the current duty cycle, but this is not the only configuration. For example, as will be described later, the flow rate output unit 52 may be configured to output the flow rate Fw when the electric pump 22 is driven with a predetermined duty cycle.

[0061] The thermal resistance derivation unit 53 derives the thermal resistance Rt of the power converter 10 when the power converter 10 is cooled under the cooling conditions of the cooling device 20, and passes the processing result to the thermal resistance characteristic derivation unit 54.

[0062] 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, the storage unit 50b has a thermal resistance map Mp3 pre-stored in it, which is information indicating the thermal resistance Rt corresponding to each flow rate Fw. Then, as shown in the frame labeled 53a in Figure 2, for example, if the flow rate Fw derived by the flow rate derivation unit 52 is Fw1, the thermal resistance derivation unit 53 derives Rt1 corresponding to Fw1 as the thermal resistance Rt.

[0063] In this 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, but this is not limited to this configuration. For example, if the vehicle 1 is equipped with a flow rate sensor capable of detecting the flow rate Fw, the thermal resistance derivation unit 53 may derive the thermal resistance Rt based on the flow rate Fw detected by this flow rate sensor. In such a case, the control device 50 does not need to be equipped with a flow rate derivation unit 52.

[0064] The thermal resistance characteristic derivation unit 54 derives a thermal resistance characteristic Rc representing the temperature reached for each loss of the power converter 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 passes the processing result to the saturation temperature / saturation temperature loss derivation unit 55.

[0065] For example, suppose a loss characteristic Lc including the first temperature loss PlsT1 and the second temperature loss PlsT2 is derived, and the thermal resistance Rt is derived as Rt1. In this case, as shown in the frame labeled 54a in Figure 2, the thermal resistance characteristic derivation unit 54 derives the first target temperature T11, which is the temperature reached by the power converter 10, when the loss of the power converter 10 is the first temperature loss PlsT1 and the thermal resistance Rt is Rt1, for example by equation (1) below. Furthermore, the thermal resistance characteristic derivation unit 54 also derives the second target temperature T12, which is the temperature reached by the power converter 10, when the loss of the power converter 10 is the second temperature loss PlsT2 and the thermal resistance Rt is Rt1, for example by equation (1) below. Note that "TW0" in equation (1) below can be, for example, the water temperature TWnow.

[0066] The temperature reached by the power converter 10 = thermal resistance Rt × power loss of the power converter 10 + TW0...(1)

[0067] The thermal resistance characteristic derivation unit 54 then derives the thermal resistance characteristic Rc based on the first achieved temperature T11 and the second achieved temperature T12. The thermal resistance characteristic Rc can be geometrically determined from the first achieved temperature T11 and the second achieved temperature T12. More specifically, as shown in the frame labeled 54a in Figure 2, the thermal resistance characteristic derivation unit 54 can, for example, derive the thermal resistance characteristic Rc as a line segment passing through coordinate point P11(PlsT1,T11) and coordinate point P12(PlsT2,T12) in a plane where the loss of the power converter 10 is on the horizontal axis and the device temperature Tj is on the vertical axis.

[0068] The saturation temperature / saturation temperature loss derivation unit 55 derives the saturation temperature Tsat and the saturation temperature loss PlsTsat 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.

[0069] Here, the saturation temperature Tsat is the temperature reached by the power converter 10 when the first motor generator MG1 is operated under predetermined operating conditions and the power converter 10 is cooled under predetermined cooling conditions. For example, in the example shown in Figure 2, the saturation temperature Tsat is the temperature reached by the power converter 10 when the first motor generator MG1 is operated under current operating conditions and the power converter 10 is cooled under current cooling conditions. Also, the loss at saturation temperature PlsTsat is the loss of the power converter 10 when the device temperature Tj is at the saturation temperature Tsat.

[0070] The saturation temperature Tsat and the loss at saturation temperature PlsTsat can be geometrically determined from the loss characteristic Lc and the thermal resistance characteristic Rc. More specifically, as shown in the frame labeled 55a in Figure 2, the saturation temperature / loss at saturation temperature derivation unit 55 can, for example, derive the loss of the power converter 10 corresponding to the intersection point CP of the loss characteristic Lc and the thermal resistance characteristic Rc as the loss at saturation temperature PlsTsat on a plane with the loss of the power converter 10 on the horizontal axis and the device temperature Tj on the vertical axis, and derive the device temperature Tj corresponding to the intersection point CP as the saturation temperature Tsat. In other words, the saturation temperature Tsat can be said to be the device temperature Tj at which the loss (in other words, heat generation) of the power converter 10 and the thermal resistance Rt are in equilibrium, and it can also be said to be the device temperature Tj at which the temperature rise of the power converter 10 due to the loss of the power converter 10 stops.

[0071] In this way, the control device 50 derives the loss of the power converter 10 corresponding to the intersection point CP of the loss characteristic Lc and the thermal resistance characteristic Rc as the loss at saturation temperature PlsTsat, and derives the device temperature Tj corresponding to the intersection point CP as the saturation temperature Tsat, thereby enabling accurate determination of the saturation temperature Tsat and the loss at saturation temperature PlsTsat through simple calculations. Furthermore, the control device 50 can also predict the saturation temperature Tsat and the loss at saturation temperature PlsTsat before the actual device temperature Tj reaches the saturation temperature Tsat.

[0072] The vehicle control unit 56 reflects the saturation temperature Tsat and / or saturation temperature loss PlsTsat derived by the saturation temperature / saturation temperature loss derivation unit 55 in the vehicle control, and the vehicle control is not particularly limited. For example, the vehicle control unit 56 may control the electric pump 22 or the power converter 10 based on the saturation temperature Tsat and / or saturation temperature loss PlsTsat. The vehicle control unit 56 may also determine the state of the vehicle 1 (e.g., whether there is an abnormality or the load state) based on the saturation temperature Tsat and / or saturation temperature loss PlsTsat. Specific examples of vehicle control based on saturation temperature Tsat and / or saturation temperature loss PlsTsat will be described later in the first to fourth use examples of the present invention, so the explanation here is omitted. Note that the vehicle control unit 56 is an example of a mobile body control unit in the present invention.

[0073] [3. Processes executed by the control unit] Next, an example of a process performed by the control device 50 will be described. Figure 3 is a flowchart showing an example of a process performed by the control device 50. The control device 50 performs the series of processes shown in Figure 3 at predetermined intervals (for example, every 1 second) while the vehicle 1 is starting up (for example, when the ignition power is on).

[0074] As shown in Figure 3, first, the control device 50 acquires information indicating, for example, the current MOT rotational speed, MOT torque, V2 voltage, water temperature TW (i.e., water temperature TWnow), and the duty cycle of the electric pump 22 (step Sp1). In addition, during the processing of step Sp1, the control device 50 may also acquire information indicating the I1 current and V1 voltage as needed.

[0075] Next, the control device 50 derives the first temperature loss PlsT1 and the second temperature loss PlsT2 based on the MOT rotational speed, MOT torque, and V2 voltage obtained in step Sp1, by referring to the loss map Mp1 (step Sp2).

[0076] Next, the control device 50 derives the loss characteristic Lc of the power converter 10 based on the first temperature loss PlsT1 and the second temperature loss PlsT2 derived in step Sp2 (step Sp3).

[0077] Next, the control device 50 derives the current flow rate Fw based on the water temperature TWnow and Duty obtained in step Sp1, by referring to the flow rate map Mp2 (step Sp4).

[0078] Next, the control device 50 derives the thermal resistance Rt of the power converter 10 based on the flow rate Fw derived by the processing in step Sp4, by referring to the thermal resistance map Mp3 (step Sp5).

[0079] Next, the control device 50 derives the thermal resistance characteristic Rc of the power converter 10 based on the first temperature loss PlsT1 and the second temperature loss PlsT2 derived in step Sp2, and the thermal resistance Rt derived in step Sp5 (step Sp6).

[0080] Next, the control device 50 derives the saturation temperature Tsat and the loss at saturation temperature PlsTsat based on the loss characteristic Lc derived by the processing in step Sp3 and the thermal resistance characteristic Rc derived by the processing in step Sp6 (step Sp7).

[0081] Then, the control device 50 controls the vehicle 1 based on the saturation temperature Tsat and / or the loss at saturation temperature PlsTsat derived from the processing in step Sp7 (step Sp8), and completes the series of processes shown in Figure 3.

[0082] As explained above, the control device 50 can derive the saturation temperature Tsat and the loss at saturation temperature PlsTsat when the first motor generator MG1 is operated under the current operating conditions and the power converter 10 is cooled under the current cooling conditions. Therefore, it becomes possible to perform vehicle control that takes into account the saturation temperature Tsat and / or the loss at saturation temperature PlsTsat. This, in turn, can contribute to improving the energy efficiency of the vehicle 1.

[0083] Furthermore, the control device 50 derives the loss characteristic Lc based on the operating conditions of the first motor generator MG1, for example, the MOT rotational speed and MOT torque, and the V2 voltage, which is the voltage value of the power exchanged between the first motor generator MG1 and the power converter 10. This makes it possible to derive the loss characteristic Lc considering the MOT rotational speed, MOT torque, and V2 voltage.

[0084] Furthermore, the control device 50 derives the flow rate Fw as the cooling condition for the power converter 10, 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. This makes it possible to appropriately derive the thermal resistance Rt without providing a flow sensor to detect the flow rate Fw of the cooling water pumped by the electric pump 22.

[0085] In the example described above, the operating conditions of the first motor generator MG1 used by the control device 50 to derive the saturation temperature Tsat and the loss at saturation temperature PlsTsat were set to the current operating conditions, but this is not limited to this. For example, the control device 50 may use arbitrary operating conditions (e.g., a predetermined V2 voltage) instead of the current operating conditions of the first motor generator MG1 (e.g., the current V2 voltage) to derive the saturation temperature Tsat and the loss at saturation temperature PlsTsat. This makes it possible, for example, to derive the saturation temperature Tsat and the loss at saturation temperature PlsTsat when the first motor generator MG1 is operated under arbitrary operating conditions and the power converter 10 is cooled under the current cooling conditions.

[0086] Furthermore, in the example described above, the cooling conditions of the power converter 10 used by the control device 50 to derive the saturation temperature Tsat and the loss at saturation temperature PlsTsat were set to the current cooling conditions, but this is not limited to this. For example, the control device 50 may use any cooling conditions (e.g., a predetermined duty cycle) instead of the current cooling conditions of the power converter 10 (e.g., the current duty cycle of the electric pump 22) to derive the saturation temperature Tsat and the loss at saturation temperature PlsTsat. This makes it possible to derive the saturation temperature Tsat and the loss at saturation temperature PlsTsat when, for example, the first motor generator MG1 is operated under the current operating conditions and the power converter 10 is cooled under any arbitrary cooling conditions.

[0087] 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 motor generator MG1, but it is not limited to this. 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 second motor generator MG2, in addition to or instead of the saturation temperature Tsat and the loss at saturation temperature PlsTsat based on the operating conditions of the first motor generator MG1. The operating conditions of the second motor generator MG2 may include, for example, the GEN rotational speed, the output torque of the second motor generator MG2 (hereinafter also referred to as "GEN torque"), the V2 voltage, etc. In this case, the control device 50 can, for example, obtain information indicating the GEN rotational speed from the GEN rotational speed sensor 34, and information indicating the V2 voltage from the second current / voltage sensor 32, and can derive information indicating the GEN torque based on the GEN rotational speed and the V2 voltage.

[0088] Furthermore, the control device 50 may also derive the saturation temperature Tsat and the loss at saturation temperature PlsTsat based on the operating conditions of the voltage converter 13. The operating conditions of the voltage converter 13 may include, for example, I1 current, V1 voltage, V2 voltage, etc. In this case, the control device 50 can obtain, for example, information indicating I1 current and V1 voltage from the first current / voltage sensor 31, and information indicating V2 voltage from the second current / voltage sensor 32.

[0089] [4. 1st usage example] Next, a first example of the present invention will be described. This first example is one in which the control device 50 controls the electric pump 22 based on the saturation temperature loss PlsTsat. In this first example, the control device 50 derives a first saturation temperature Tsat1, a second saturation temperature Tsat2, and a third saturation temperature Tsat3 as saturation temperatures Tsat, and derives a first saturation temperature loss PlsTsat1, a second saturation temperature loss PlsTsat2, and a third saturation temperature loss PlsTsat3 as saturation temperature losses PlsTsat.

[0090] 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 motor generator MG1). The loss at the first saturation temperature PlsTsat1 is the loss at the saturation temperature PlsTsat based on the MOT-INV loss. Specific derivation examples of the first saturation temperature Tsat1 and the loss at the first saturation temperature PlsTsat1 will be described later using Figure 4, etc.

[0091] 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 motor generator MG2). The loss at the second saturation temperature PlsTsat2 is the loss at the saturation temperature PlsTsat based on the GEN-INV loss. Specific derivation examples of the second saturation temperature Tsat2 and the loss at the second saturation temperature PlsTsat2 will be described later using Figure 5, etc.

[0092] The third saturation temperature Tsat3 is the saturation temperature Tsat based on the VCU loss (i.e., the operating conditions of the voltage converter 13). The loss at the third saturation temperature PlsTsat3 is the loss at the saturation temperature PlsTsat based on the VCU loss. Specific derivation examples of the third saturation temperature Tsat3 and the loss at the third saturation temperature PlsTsat3 will be described later using Figure 6, etc.

[0093] In other words, in the first example of use, the control device 50 derives the saturation temperature Tsat and the loss at saturation temperature PlsTsat for each motor generator provided by the vehicle 1, such as the first motor generator MG1 and the second motor generator MG2. This makes it possible to perform vehicle control that takes into account the saturation temperature Tsat and / or loss at saturation temperature PlsTsat corresponding to each motor generator, even when the vehicle 1 is equipped with multiple motor generators.

[0094] (4-1. Method for deriving the first saturation temperature and the loss at the first saturation temperature in the first use case) First, we will explain how to derive the first saturation temperature Tsat1 and the loss at the first saturation temperature PlsTsat1 in the first use case. Figure 4 shows an example of how to derive the first saturation temperature Tsat1 and the loss at the first saturation temperature PlsTsat1 in the first use case.

[0095] In the first example of use, the control device 50 (for example, the loss characteristic derivation unit 51) derives the first temperature loss PlsT1a, which is the MOT-INV loss when the current MOT rotation speed, MOT torque, and V2 voltage are set to 25°C, by referring to the loss map Mp1a, as shown in the frame labeled 401 in Figure 4. Here, the loss map Mp1a is information that shows the MOT-INV loss corresponding to each combination of MOT rotation speed, MOT torque, V2 voltage, and device temperature Tj, and is stored in advance in the storage unit 50b, for example. Note that the loss map Mp1a only needs to contain information that can identify the MOT-INV loss from the MOT rotation speed, MOT torque, V2 voltage, and device temperature Tj, and may be configured as a group of multiple maps in the data, similar to the loss map Mp1.

[0096] Furthermore, as shown in the frame labeled 401 in Figure 4, the control device 50 derives the second temperature loss PlsT2a and the third temperature loss PlsT3a in the same manner as the first temperature loss PlsT1a. Here, the second temperature loss PlsT2a can be, for example, the MOT-INV loss when the device temperature Tj is 75°C at the current MOT rotation speed, MOT torque, and V2 voltage. The third temperature loss PlsT3a can be, for example, the MOT-INV loss when the device temperature Tj is 175°C at the current MOT rotation speed, MOT torque, and V2 voltage.

[0097] Next, the control device 50 (for example, the loss characteristic derivation unit 51) derives a MOT-INV loss characteristic Lc1, which represents the MOT-INV loss for each device temperature Tj, based on the first temperature loss PlsT1a, the second temperature loss PlsT2a, and the third temperature loss PlsT3a, as shown in the frame labeled 402 in Figure 4. The MOT-INV loss characteristic Lc1 is an example of a loss characteristic Lc, and like the loss characteristic Lc, it can be geometrically determined from, for example, the first temperature loss PlsT1a, the second temperature loss PlsT2a, and the third temperature loss PlsT3a.

[0098] Next, the control device 50 (for example, the flow rate derivation unit 52) ​​derives the flow rate Fw corresponding to the water temperature TWnow for each duty cycle of the electric pump 22, as shown in the frame labeled 403 in Figure 4, by referring to the flow rate map Mp2. For example, as shown in Figure 4, the control device 50 derives the flow rate Fw for each of the cases where the duty cycle of the electric pump 22 is 40%, 60%, and 80%. In the example shown in Figure 4, Fw1 is derived as the flow rate Fw when the duty cycle of the electric pump 22 is 40%, Fw2 as the flow rate Fw when it is 60%, and Fw3 as the flow rate Fw when it is 80%.

[0099] Next, the control device 50 (for example, the thermal resistance derivation unit 53) derives the thermal resistance Rt corresponding to each flow rate Fw derived by the above process, based on the frame labeled 404 in Figure 4, by referring to the thermal resistance map Mp3. In the example shown in Figure 4, Rt1 is derived as the thermal resistance Rt when the flow rate Fw is Fw1 (in other words, when the duty cycle is 40%), Rt2 is derived as the thermal resistance Rt when it is Fw2 (in other words, when the duty cycle is 60%), and Rt3 is derived as the thermal resistance Rt when it is Fw3 (in other words, when the duty cycle is 80%).

[0100] Next, the control device 50 (for example, the thermal resistance characteristic derivation unit 54) derives a thermal resistance characteristic Rc corresponding to each thermal resistance Rt, based on each thermal resistance Rt derived by the above process, as shown in the frame labeled 405 in Figure 4. In the example shown in Figure 4, the thermal resistance characteristic Rc1a is derived as the thermal resistance characteristic Rc when the thermal resistance Rt is Rt1 (in other words, when the duty cycle is 40%). Also, the thermal resistance characteristic Rc2a is derived as the thermal resistance characteristic Rc when the thermal resistance Rt is Rt2 (in other words, when the duty cycle is 60%). Furthermore, the thermal resistance characteristic Rc3a is derived as the thermal resistance characteristic Rc when the thermal resistance Rt is Rt3a (in other words, when the duty cycle is 80%).

[0101] For example, the thermal resistance characteristic Rc1a can be geometrically determined from the first temperature reached when the power converter 10's loss at the first temperature is PlsT1a and its thermal resistance Rt is Rt1, the second temperature reached when the power converter 10's loss at the second temperature is PlsT2a and its thermal resistance Rt is Rt1, and the third temperature reached when the power converter 10's loss at the third temperature is PlsT3a and its thermal resistance Rt is Rt1. The first, second, and third temperatures can each be determined, for example, by equation (1) above. Furthermore, the thermal resistance characteristics Rc2a and Rc3a can be determined in the same manner as the thermal resistance characteristic Rc1a.

[0102] Next, the control device 50 (for example, the saturation temperature / saturation temperature loss derivation unit 55) derives the first saturation temperature Tsat1 and the first saturation temperature loss PlsTsat1 for each thermal resistance characteristic Rc, based on the MOT-INV loss characteristic Lc1 derived by the above process and the respective thermal resistance characteristics Rc.

[0103] For example, the first saturation temperature Tsat1 and the loss at the first saturation temperature PlsTsat1, based on the MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc1a, can be determined, for example, as the intersection point of the MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc1a on a plane where the horizontal axis represents the loss of the power converter 10 (in this case, the MOT-INV loss) and the vertical axis represents the device temperature Tj. In the example shown in Figure 4, 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 at the first saturation temperature PlsTsat1 based on the MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc1a. Furthermore, the first saturation temperature Tsat1 and the loss at the first saturation temperature PlsTsat1, based on the MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc1a, can also be said to be the first saturation temperature Tsat1 and the loss at the first saturation temperature PlsTsat1 when the duty cycle of the electric pump 22 is set to 40%.

[0104] Similarly, the control device 50 derives the first saturation temperature Tsat1 and the loss at the first saturation temperature PlsTsat1 based on the MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc2a, and the first saturation temperature Tsat1 and the loss at the first saturation temperature PlsTsat1 based on the MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc3a. This allows the control device 50 to obtain the first saturation temperature Tsat1 and the loss at the first saturation temperature PlsTsat1 for each thermal resistance characteristic Rc, in other words, for each duty cycle of the electric pump 22.

[0105] (4-2. Method for deriving the second saturation temperature and loss at the second saturation temperature in the first use case) Next, we will explain how to derive the second saturation temperature Tsat2 and the loss at the second saturation temperature PlsTsat2 in the first use case. Figure 5 shows an example of how to derive the second saturation temperature Tsat2 and the loss at the second saturation temperature PlsTsat2 in the first use case.

[0106] In the first example of use, the control device 50 (for example, the loss characteristic derivation unit 51) derives the first temperature loss PlsT1b, which is the GEN-INV loss when the device temperature Tj is 25°C, for example, at the current GEN rotational speed, GEN torque, and V2 voltage, by referring to the loss map Mp1b, as shown in the frame labeled 501 in Figure 5. Here, the loss map Mp1b is information that shows the GEN-INV loss corresponding to each combination of GEN rotational speed, GEN torque, V2 voltage, and device temperature Tj, and is stored in advance in the storage unit 50b, for example. Note that the loss map Mp1b only needs to contain information that can identify the GEN-INV loss from the GEN rotational speed, GEN torque, V2 voltage, and device temperature Tj, and like the loss map Mp1, it may be configured as a group of multiple maps in the data.

[0107] Furthermore, as shown in the frame labeled 501 in Figure 5, the control device 50 derives the second temperature loss PlsT2b and the third temperature loss PlsT3b in the same manner as the first temperature loss PlsT1b. Here, the second temperature loss PlsT2b can be, for example, the GEN-INV loss when the current GEN rotational speed, GEN torque, and V2 voltage are used, and the device temperature Tj is 75°C. The third temperature loss PlsT3b can be, for example, the GEN-INV loss when the current GEN rotational speed, GEN torque, and V2 voltage are used, and the device temperature Tj is 175°C.

[0108] Next, the control device 50 (for example, the loss characteristic derivation unit 51) derives a GEN-INV loss characteristic Lc2, which represents the GEN-INV loss for each device temperature Tj, based on the first temperature loss PlsT1b, the second temperature loss PlsT2b, and the third temperature loss PlsT3b, as shown in the frame labeled 502 in Figure 5. The GEN-INV loss characteristic Lc2 is another example of the loss characteristic Lc, and like the loss characteristic Lc, it can be geometrically determined from, for example, the first temperature loss PlsT1b, the second temperature loss PlsT2b, and the third temperature loss PlsT3b.

[0109] Next, the control device 50 (for example, the flow rate derivation unit 52) ​​derives the flow rate Fw corresponding to the water temperature TWnow for each duty cycle of the electric pump 22, as shown in the frame labeled 503 in Figure 5, by referring to the flow rate map Mp2. In the example shown in Figure 5, Fw1 is derived as the flow rate Fw when the duty cycle of the electric pump 22 is 40%, Fw2 as the flow rate Fw when it is 60%, and Fw3 as the flow rate Fw when it is 80%.

[0110] Note that the process shown in the frame labeled 503 in Figure 5 is the same process as the process shown in the frame labeled 403 in Figure 4. Therefore, if the control device 50 has already executed the process shown in the frame labeled 403 in Figure 4, it may not execute the process shown in the frame labeled 503 in Figure 5 again, but instead use the processing result of the process shown in the frame labeled 403 in Figure 4 as is.

[0111] Next, the control device 50 (for example, the thermal resistance derivation unit 53) derives the thermal resistance Rt corresponding to each flow rate Fw derived by the above process, based on the frame labeled 504 in Figure 5, by referring to the thermal resistance map Mp3. In the example shown in Figure 5, Rt1 is derived as the thermal resistance Rt when the flow rate Fw is Fw1 (in other words, when the duty cycle is 40%), Rt2 is derived as the thermal resistance Rt when the flow rate is Fw2 (in other words, when the duty cycle is 60%), and Rt3 is derived as the thermal resistance Rt when the flow rate is Fw3 (in other words, when the duty cycle is 80%).

[0112] Note that the process shown in the frame labeled 504 in Figure 5 is the same process as the process shown in the frame labeled 404 in Figure 4. Therefore, if the control device 50 has already executed the process shown in the frame labeled 404 in Figure 4, it may not execute the process shown in the frame labeled 504 in Figure 5 again, but instead use the processing result of the process shown in the frame labeled 404 in Figure 4 as is.

[0113] Next, the control device 50 (for example, the thermal resistance characteristic derivation unit 54) derives a thermal resistance characteristic Rc corresponding to each thermal resistance Rt, based on each thermal resistance Rt derived by the above process, as shown in the frame labeled with reference numeral 505 in Figure 5. In the example shown in Figure 5, the thermal resistance characteristic Rc1b is derived as the thermal resistance characteristic Rc when the thermal resistance Rt is Rt1 (in other words, when the duty cycle is 40%). Also, the thermal resistance characteristic Rc2b is derived as the thermal resistance characteristic Rc when the thermal resistance Rt is Rt2 (in other words, when the duty cycle is 60%). Furthermore, the thermal resistance characteristic Rc3b is derived as the thermal resistance characteristic Rc when the thermal resistance Rt is Rt3a (in other words, when the duty cycle is 80%).

[0114] For example, the thermal resistance characteristic Rc1b can be geometrically determined from the first temperature reached when the power converter 10's loss at the first temperature is PlsT1b and the thermal resistance Rt is Rt1, the second temperature reached when the power converter 10's loss at the second temperature is PlsT2b and the thermal resistance Rt is Rt1, and the third temperature reached when the power converter 10's loss at the third temperature is PlsT3b and the thermal resistance Rt is Rt1. The first, second, and third temperatures can each be determined, for example, by equation (1) above. Furthermore, the thermal resistance characteristics Rc2b and Rc3b can be determined in the same manner as the thermal resistance characteristic Rc1b.

[0115] Next, the control device 50 (for example, the saturation temperature / saturation temperature loss derivation unit 55) derives the second saturation temperature Tsat2 and the loss at the second saturation temperature PlsTsat2 for each thermal resistance characteristic Rc, based on the GEN-INV loss characteristic Lc2 derived by the above process and the respective thermal resistance characteristics Rc, as shown in the frame labeled 506 in Figure 5.

[0116] For example, the second saturation temperature Tsat2 and the loss at the second saturation temperature PlsTsat2, based on the GEN-INV loss characteristic Lc2 and the thermal resistance characteristic Rc1b, can be determined, for example, as the intersection point of the GEN-INV loss characteristic Lc2 and the thermal resistance characteristic Rc1b on a plane where the loss of the power converter 10 (in this case, GEN-INV loss) is on the horizontal axis and the device temperature Tj is on the vertical axis. In the example shown in Figure 5, 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 at the second saturation temperature PlsTsat2 based on the GEN-INV loss characteristic Lc2 and the thermal resistance characteristic Rc1b. Furthermore, the second saturation temperature Tsat2 and the loss at the second saturation temperature PlsTsat2, based on the GEN-INV loss characteristic Lc2 and the thermal resistance characteristic Rc1b, can also be said to be the second saturation temperature Tsat2 and the loss at the second saturation temperature PlsTsat2 when the duty cycle of the electric pump 22 is set to 40%.

[0117] Similarly, the control device 50 derives the second saturation temperature Tsat2 and the loss at the second saturation temperature PlsTsat2 based on the GEN-INV loss characteristic Lc2 and the thermal resistance characteristic Rc2b, and the second saturation temperature Tsat2 and the loss at the second saturation temperature PlsTsat2 based on the GEN-INV loss characteristic Lc2 and the thermal resistance characteristic Rc3b. This allows the control device 50 to obtain the second saturation temperature Tsat2 and the loss at the second saturation temperature PlsTsat2 for each thermal resistance characteristic Rc, in other words, for each duty cycle of the electric pump 22.

[0118] (4-3. Method for deriving the third saturation temperature and the loss at the third saturation temperature in the first example of use) Next, we will explain how to derive the third saturation temperature Tsat3 and the loss at the third saturation temperature PlsTsat3 in the first use case. Figure 6 shows an example of how to derive the third saturation temperature Tsat3 and the loss at the third saturation temperature PlsTsat3 in the first use case.

[0119] In the first example of use, the control device 50 (for example, the loss characteristic derivation unit 51) derives the first temperature loss PlsT1c, which is the VCU loss when the current I1 current, V1 voltage, and V2 voltage are set to 25°C, by referring to the loss map Mp1c, as shown in the frame labeled 601 in Figure 6. Here, the loss map Mp1c is information that shows the VCU loss corresponding to each combination of I1 current, V1 voltage, V2 voltage, and device temperature Tj, and is stored in advance in the storage unit 50b, for example. Note that the loss map Mp1c only needs to be information that can identify the VCU loss from the I1 current, V1 voltage, V2 voltage, and device temperature Tj, and like the loss map Mp1, it may be configured as a group of maps in the data.

[0120] Furthermore, as shown in the frame labeled 601 in Figure 6, the control device 50 derives the second temperature loss PlsT2c and the third temperature loss PlsT3c in the same manner as the first temperature loss PlsT1c. Here, the second temperature loss PlsT2c can be, for example, the VCU loss when the current I1 current, V1 voltage, and V2 voltage are present and the device temperature Tj is 75°C. Similarly, the third temperature loss PlsT3b can be, for example, the VCU loss when the current I1 current, V1 voltage, and V2 voltage are present and the device temperature Tj is 175°C.

[0121] Next, the control device 50 (for example, the loss characteristic derivation unit 51) derives a VCU loss characteristic Lc3, which represents the VCU loss for each device temperature Tj, based on the first temperature loss PlsT1c, the second temperature loss PlsT2c, and the third temperature loss PlsT3c, as shown in the frame labeled 602 in Figure 6. The VCU loss characteristic Lc3 is another example of the loss characteristic Lc, and like the loss characteristic Lc, it can be geometrically determined from, for example, the first temperature loss PlsT1c, the second temperature loss PlsT2c, and the third temperature loss PlsT3c.

[0122] Next, the control device 50 (for example, the flow rate derivation unit 52) ​​derives the flow rate Fw corresponding to the water temperature TWnow for each duty cycle of the electric pump 22, as shown in the frame labeled 603 in Figure 6, by referring to the flow rate map Mp2. In the example shown in Figure 6, Fw1 is derived as the flow rate Fw when the duty cycle of the electric pump 22 is 40%, Fw2 as the flow rate Fw when it is 60%, and Fw3 as the flow rate Fw when it is 80%.

[0123] Note that the process shown in the frame labeled 603 in Figure 6 is the same process as the process shown in the frame labeled 403 in Figure 4. Therefore, if the control device 50 has already executed the process shown in the frame labeled 403 in Figure 4, it may not execute the process shown in the frame labeled 603 in Figure 6 again, but instead use the processing result of the process shown in the frame labeled 403 in Figure 4 as is.

[0124] Next, the control device 50 (for example, the thermal resistance derivation unit 53) derives the thermal resistance Rt corresponding to each flow rate Fw derived by the above process, based on the frame labeled 604 in Figure 6, by referring to the thermal resistance map Mp3. In the example shown in Figure 6, Rt1 is derived as the thermal resistance Rt when the flow rate Fw is Fw1 (in other words, when the duty cycle is 40%), Rt2 is derived as the thermal resistance Rt when it is Fw2 (in other words, when the duty cycle is 60%), and Rt3 is derived as the thermal resistance Rt when it is Fw3 (in other words, when the duty cycle is 80%).

[0125] Note that the process shown in the frame labeled 604 in Figure 6 is the same process as the process shown in the frame labeled 404 in Figure 4. Therefore, if the control device 50 has already executed the process shown in the frame labeled 404 in Figure 4, it may not execute the process shown in the frame labeled 604 in Figure 6 again, but instead use the processing result of the process shown in the frame labeled 404 in Figure 4 as is.

[0126] Next, the control device 50 (for example, the thermal resistance characteristic derivation unit 54) derives a thermal resistance characteristic Rc corresponding to each thermal resistance Rt, based on each thermal resistance Rt derived by the above process, as shown in the frame labeled 605 in Figure 6. In the example shown in Figure 6, the thermal resistance characteristic Rc1c is derived as the thermal resistance characteristic Rc when the thermal resistance Rt is Rt1 (in other words, when the duty cycle is 40%). Also, the thermal resistance characteristic Rc2c is derived as the thermal resistance characteristic Rc when the thermal resistance Rt is Rt2 (in other words, when the duty cycle is 60%). Furthermore, the thermal resistance characteristic Rc3c is derived as the thermal resistance characteristic Rc when the thermal resistance Rt is Rt3 (in other words, when the duty cycle is 80%).

[0127] For example, the thermal resistance characteristic Rc1c can be geometrically determined from the first temperature reached when the power converter 10's loss at the first temperature is PlsT1c and the thermal resistance Rt is Rt1, the second temperature reached when the power converter 10's loss at the second temperature is PlsT2c and the thermal resistance Rt is Rt1, and the third temperature reached when the power converter 10's loss at the third temperature is PlsT3c and the thermal resistance Rt is Rt1. The first, second, and third temperatures can each be determined, for example, by equation (1) above. Furthermore, the thermal resistance characteristics Rc2c and Rc3c can be determined in the same manner as the thermal resistance characteristic Rc1c.

[0128] Next, the control device 50 (for example, the saturation temperature / saturation temperature loss derivation unit 55) derives the third saturation temperature Tsat3 and the loss at the third saturation temperature PlsTsat3 for each thermal resistance characteristic Rc, based on the VCU loss characteristic Lc3 derived by the above process and the respective thermal resistance characteristics Rc, as shown in the frame labeled 606 in Figure 6.

[0129] For example, the third saturation temperature Tsat3 and the loss at the third saturation temperature PlsTsat3, based on the VCU loss characteristic Lc3 and the thermal resistance characteristic Rc1c, can be determined, for example, as the intersection point of the VCU loss characteristic Lc3 and the thermal resistance characteristic Rc1c on a plane where the horizontal axis represents the loss of the power converter 10 (in this case, VCU loss) and the vertical axis represents the device temperature Tj. In the example shown in Figure 6, 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 at the third saturation temperature PlsTsat3 based on the VCU loss characteristic Lc3 and the thermal resistance characteristic Rc1c. Furthermore, the third saturation temperature Tsat3 and the loss at the third saturation temperature PlsTsat3, based on the VCU loss characteristic Lc3 and the thermal resistance characteristic Rc1c, can also be said to be the third saturation temperature Tsat3 and the loss at the third saturation temperature PlsTsat3 when the duty cycle of the electric pump 22 is set to 40%.

[0130] Similarly, the control device 50 derives the third saturation temperature Tsat3 and the loss at the third saturation temperature PlsTsat3 based on the VCU loss characteristic Lc3 and the thermal resistance characteristic Rc2c, and the third saturation temperature Tsat3 and the loss at the third saturation temperature PlsTsat3 based on the VCU loss characteristic Lc3 and the thermal resistance characteristic Rc3c. This allows the control device 50 to obtain the third saturation temperature Tsat3 and the loss at the third saturation temperature PlsTsat3 for each thermal resistance characteristic Rc, in other words, for each duty cycle of the electric pump 22.

[0131] (4-4. Searching for the optimal duty cycle) In the first example of use, the control device 50 searches for the optimal duty cycle of the electric pump 22 based on the first saturation temperature loss PlsTsat1, second saturation temperature loss PlsTsat2, and third saturation temperature loss PlsTsat3 for each duty cycle of the electric pump 22 derived as described above. Here, the optimal duty cycle is the duty cycle of the electric pump 22 in which the sum of the first saturation temperature loss PlsTsat1, second saturation temperature loss PlsTsat2, third saturation temperature loss PlsTsat3, and the power consumption of the electric pump 22 is minimized when the V2 voltage is set to a predetermined value (for example, the current V2 voltage).

[0132] Figure 7 shows an example of a method for finding the optimal duty cycle in the first use case. In Figure 7, the horizontal axis represents the duty cycle of the electric pump 22, and the vertical axis represents the loss (in other words, power consumption) of the vehicle 1.

[0133] In searching for the optimal duty cycle, the control device 50 derives, for example, the first saturation temperature loss characteristic 701, the second saturation temperature loss characteristic 702, and the third saturation temperature loss characteristic 703 shown in Figure 7.

[0134] Here, the first saturation temperature loss characteristic 701 represents the first saturation temperature loss PlsTsat1 (i.e., the saturation temperature loss PlsTsat based on the MOT-INV loss) of the electric pump 22 for each duty cycle, or in other words, it represents the first saturation temperature loss PlsTsat1 corresponding to each duty cycle. For example, the first saturation temperature loss characteristic 701 can be geometrically determined from the first saturation temperature loss PlsTsat1 of the electric pump 22 for each duty cycle obtained by the process shown in Figure 4.

[0135] Furthermore, the second saturation temperature loss characteristic 702 represents the second saturation temperature loss PlsTsat2 for each duty cycle of the electric pump 22 (i.e., the saturation temperature loss PlsTsat based on the GEN-INV loss), or in other words, it represents the second saturation temperature loss PlsTsat2 corresponding to each duty cycle. For example, the second saturation temperature loss characteristic 702 can be geometrically determined from the second saturation temperature loss PlsTsat2 for each duty cycle of the electric pump 22 obtained by the process shown in Figure 5.

[0136] Furthermore, the third saturation temperature loss characteristic 703 represents the third saturation temperature loss PlsTsat3 (i.e., the saturation temperature loss PlsTsat based on VCU loss) for each duty cycle of the electric pump 22. In other words, it represents the third saturation temperature loss PlsTsat3 corresponding to each duty cycle. For example, the third saturation temperature loss characteristic 703 can be geometrically determined from the third saturation temperature loss PlsTsat3 for each duty cycle of the electric pump 22 obtained by the process shown in Figure 6.

[0137] Furthermore, the EWP loss characteristics 704 shown in Figure 7 represent the power consumption of the electric pump 22 for each duty cycle, or in other words, the power consumption of the electric pump 22 according to each duty cycle. For example, information showing the EWP loss characteristics 704 is pre-stored in the memory unit 50b.

[0138] In the first example of use, the control device 50 derives a total loss characteristic 710 based, for example, on the first saturation temperature loss characteristic 701, the second saturation temperature loss characteristic 702, the third saturation temperature loss characteristic 703, and the EWP loss characteristic 704. Here, the total loss characteristic 710 represents the sum of the first saturation temperature loss PlsTsat1, the second saturation temperature loss PlsTsat2, the third saturation temperature loss PlsTsat3, and the power consumption of the electric pump 22 for each duty cycle of the electric pump 22. In other words, the total loss characteristic 710 represents the sum of the first saturation temperature loss PlsTsat1, the second saturation temperature loss PlsTsat2, the third saturation temperature loss PlsTsat3, and the power consumption of the electric pump 22, corresponding to each duty cycle.

[0139] The control device 50 then searches for the optimal duty cycle based on the total loss characteristics 710. More specifically, the control device 50 searches for the optimal duty cycle from among the duty cycles included in the "applicable duty cycle range," which is the range of duty cycles that can be adopted as the duty cycle for actually driving the electric pump 22, and finds the duty cycle that minimizes the sum of the first saturation temperature loss PlsTsat1, the second saturation temperature loss PlsTsat2, the third saturation temperature loss PlsTsat3, and the power consumption of the electric pump 22. In the example shown in Figure 7, a duty cycle of 80% is found as the optimal duty cycle. The applicable duty cycle range is predetermined by the manufacturer of the vehicle 1, etc.

[0140] Once the control device 50 has found the optimal duty cycle in this manner, it drives the electric pump 22 with that optimal duty cycle. This allows the electric pump 22 to be appropriately controlled with a duty cycle that takes into account MOT-INV losses, GEN-INV losses, VCU losses, and the power consumption of the electric pump 22, thereby reducing the power consumption in the vehicle 1.

[0141] In the example described here, the control device 50 searches for the optimal duty cycle based on the first saturation temperature loss characteristic 701, the second saturation temperature loss characteristic 702, the third saturation temperature loss characteristic 703, and the EWP loss characteristic 704, but it is not limited to this.

[0142] For example, if vehicle 1 is running in EV driving mode, or if vehicle 1 is a BEV (Battery Electric Vehicle) and does not have a second motor generator MG2, the control device 50 may search for the optimal duty cycle based on the first saturation temperature loss characteristic 701, the third saturation temperature loss characteristic 703, and the EWP loss characteristic 704. Furthermore, if the power consumption of the electric pump 22 is sufficiently small compared to the losses of the power converter 10, the control device 50 does not need to use the EWP loss characteristic 704 to search for the optimal duty cycle. Alternatively, the control device 50 may simply search for the optimal duty cycle using only one of the first saturation temperature loss characteristic 701, the second saturation temperature loss characteristic 702, and the third saturation temperature loss characteristic 703.

[0143] As described above, in the first example of use, the control device 50 derives the flow rate Fw for when the driving state of the electric pump 22 is set to a predetermined first state (e.g., Duty 40%) and a predetermined second state (e.g., Duty 60%), and derives the thermal resistance Rt for the first state and the second state based on the derived flow rates Fw. The control device 50 then derives the saturation temperature Tsat (e.g., first saturation temperature Tsat1 or second saturation temperature Tsat2) and the saturation temperature loss PlsTsat (e.g., first saturation temperature loss PlsTsat1 or second saturation temperature loss PlsTsat2) for the first state and the second state, respectively, based on the loss characteristics Lc of the power converter 10 (e.g., MOT-INV loss characteristics Lc1 or GEN-INV loss characteristics Lc2) and the thermal resistance characteristics Rc (e.g., thermal resistance characteristics Rc1a, Rc1b or thermal resistance characteristics Rc2a, Rc2b) corresponding to the derived thermal resistance Rt, and controls the electric pump 22 based on the respective saturation temperature loss PlsTsat. This makes it possible to control the electric pump 22 while considering the saturation temperature loss PlsTsat for each flow rate Fw.

[0144] [5.Second usage example] 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 converter 10 based on the saturation temperature loss PlsTsat. In the second application example, as in the first application example, the control device 50 derives a first saturation temperature Tsat1, a second saturation temperature Tsat2, and a third saturation temperature Tsat3 as saturation temperatures Tsat, and derives a first saturation temperature loss PlsTsat1, a second saturation temperature loss PlsTsat2, and a third saturation temperature loss PlsTsat3 as saturation temperature losses PlsTsat. In the following, the explanation will focus on the differences from the explanation of the first application example described above, and explanations of parts that are the same as in the explanation of the first application example will be omitted as appropriate.

[0145] (Method for deriving the first saturation temperature and loss at the first saturation temperature in the second use case) Figure 8 shows an example of how to derive the first saturation temperature Tsat1 and the loss at the first saturation temperature PlsTsat1 in the second application example.

[0146] In the second example of use, the control device 50 (for example, the loss characteristic derivation unit 51) derives the first temperature loss PlsT1d, which is the MOT-INV loss when the current MOT rotation speed and MOT torque are set, the V2 voltage is set to a predetermined first voltage (200[V] in the example shown in Figure 8), and the device temperature Tj is set to 25[°C], by referring to the loss map Mp1a.

[0147] Furthermore, as shown in the frame labeled 801 in Figure 8, the control device 50 derives the second temperature loss PlsT2d and the third temperature loss PlsT3d in the same manner as the first temperature loss PlsT1d. Here, the second temperature loss PlsT2d can be, for example, the MOT-INV loss when the current MOT rotational speed and MOT torque are set to the first voltage V2 and the device temperature Tj is 75°C. Similarly, the third temperature loss PlsT3d can be, for example, the MOT-INV loss when the current MOT rotational speed and MOT torque are set to the first voltage V2 and the device temperature Tj is 175°C.

[0148] Next, the control device 50 (for example, the loss characteristic derivation unit 51) derives the MOT-INV loss characteristic Lc1d as the MOT-INV loss characteristic Lc1, based on the first temperature loss PlsT1d, the second temperature loss PlsT2d, and the third temperature loss PlsT3d, as shown in the frame labeled 802 in Figure 8. The MOT-INV loss characteristic Lc1d can be geometrically determined, for example, from the first temperature loss PlsT1d, the second temperature loss PlsT2d, and the third temperature loss PlsT3d.

[0149] Next, as shown in the frame labeled 801 in Figure 8, the control device 50 derives the first temperature loss PlsT1e, which is the MOT-INV loss when the current MOT rotational speed and MOT torque are used, the V2 voltage is set to a predetermined second voltage (350[V] in the example shown in Figure 8), and the device temperature Tj is set to 25[°C], by referring to the loss map Mp1a.

[0150] Furthermore, as shown in the frame labeled 801 in Figure 8, the control device 50 derives the second temperature loss PlsT2e and the third temperature loss PlsT3e in the same manner as the first temperature loss PlsT1e. Here, the second temperature loss PlsT2e can be, for example, the MOT-INV loss when the current MOT rotational speed and MOT torque are set to the second voltage V2 and the device temperature Tj is 75°C. Similarly, the third temperature loss PlsT3e can be, for example, the MOT-INV loss when the current MOT rotational speed and MOT torque are set to the second voltage V2 and the device temperature Tj is 175°C.

[0151] Next, the control device 50 (for example, the loss characteristic derivation unit 51) derives the MOT-INV loss characteristic Lc1e as the MOT-INV loss characteristic Lc1, based on the first temperature loss PlsT1e, the second temperature loss PlsT2e, and the third temperature loss PlsT3e, as shown in the frame labeled 802 in Figure 8. The MOT-INV loss characteristic Lc1e can be geometrically determined, for example, from the first temperature loss PlsT1e, the second temperature loss PlsT2e, and the third temperature loss PlsT3e.

[0152] Next, the control device 50, as shown in the frame labeled 801 in Figure 8, derives the first temperature loss PlsT1f, which is the MOT-INV loss when the current MOT rotational speed and MOT torque are used, the V2 voltage is set to a predetermined third voltage (500[V] in the example shown in Figure 8), and the device temperature Tj is set to 25[°C], by referring to the loss map Mp1a.

[0153] Furthermore, as shown in the frame labeled 801 in Figure 8, the control device 50 derives the second temperature loss PlsT2f and the third temperature loss PlsT3f in the same manner as the first temperature loss PlsT1f. Here, the second temperature loss PlsT2f can be, for example, the MOT-INV loss when the current MOT rotational speed and MOT torque are set to the third voltage V2 and the device temperature Tj is 75°C. Similarly, the third temperature loss PlsT3f can be, for example, the MOT-INV loss when the current MOT rotational speed and MOT torque are set to the third voltage V2 and the device temperature Tj is 175°C.

[0154] Next, the control device 50 (for example, the loss characteristic derivation unit 51) derives the MOT-INV loss characteristic Lc1f as the MOT-INV loss characteristic Lc1, based on the first temperature loss PlsT1f, the second temperature loss PlsT2f, and the third temperature loss PlsT3f, as shown in the frame labeled 802 in Figure 8. The MOT-INV loss characteristic Lc1f can be geometrically determined, for example, from the first temperature loss PlsT1f, the second temperature loss PlsT2f, and the third temperature loss PlsT3f.

[0155] Thus, in the second example of use, the control device 50 derives the MOT-INV loss characteristics Lc1 when the V2 voltage is set to multiple different voltage values, in other words, the MOT-INV loss characteristics Lc1 for each V2 voltage. Then, the control device 50 derives the first saturation temperature Tsat1 and the loss at the first saturation temperature PlsTsat1 for each V2 voltage from the intersection of each MOT-INV loss characteristic Lc1 and the thermal resistance characteristic Rc when the Duty cycle of the electric pump 22 is set to a predetermined value (for example, the current Duty cycle) (for example, the intersection on a plane with the loss of the power converter 10 on the horizontal axis and the device temperature Tj on the vertical axis).

[0156] Similarly, the control device 50 also derives the second saturation temperature Tsat2 and the loss at the second saturation temperature PlsTsat2 for each V2 voltage, and the third saturation temperature Tsat3 and the loss at the third saturation temperature PlsTsat3 for each V2 voltage.

[0157] (5-2. Searching for the optimal V2 voltage) In the second example of use, the control device 50 searches for the optimal V2 voltage based on the first saturation temperature loss PlsTsat1, second saturation temperature loss PlsTsat2, and third saturation temperature loss PlsTsat3 for each V2 voltage derived as described above. Here, the optimal V2 voltage is the voltage value that minimizes the sum of the first saturation temperature loss PlsTsat1, second saturation temperature loss PlsTsat2, third saturation temperature loss PlsTsat3, and the power consumption of the electric pump 22, when the duty cycle of the electric pump 22 is set to a predetermined value (for example, the current duty cycle).

[0158] Figure 9 shows an example of a method for finding the optimal V2 voltage in the second use case. In Figure 9, the horizontal axis represents the V2 voltage, and the vertical axis represents the loss (in other words, power consumption) of vehicle 1.

[0159] In searching for the optimal V2 voltage, the control device 50 derives, for example, the first saturation temperature loss characteristic 901, the second saturation temperature loss characteristic 902, and the third saturation temperature loss characteristic 903 shown in Figure 9.

[0160] Here, the first saturation temperature loss characteristic 901 represents the first saturation temperature loss PlsTsat1 for each V2 voltage (i.e., the saturation temperature loss PlsTsat based on the MOT-INV loss), or in other words, it represents the first saturation temperature loss PlsTsat1 corresponding to each voltage value as V2. For example, the first saturation temperature loss characteristic 901 can be geometrically determined from the first saturation temperature loss PlsTsat1 for each V2 voltage obtained by the process shown in Figure 8.

[0161] Furthermore, the second saturation temperature loss characteristic 902 represents the second saturation temperature loss PlsTsat2 for each V2 voltage (i.e., the saturation temperature loss PlsTsat based on GEN-INV loss), or in other words, it represents the second saturation temperature loss PlsTsat2 corresponding to each voltage value of V2. For example, the second saturation temperature loss characteristic 902 can be geometrically determined from the second saturation temperature loss PlsTsat2 for each V2 voltage.

[0162] Furthermore, the third saturation temperature loss characteristic 903 represents the third saturation temperature loss PlsTsat3 for each V2 voltage (i.e., the saturation temperature loss PlsTsat based on VCU loss), or in other words, it represents the third saturation temperature loss PlsTsat3 corresponding to each voltage value as V2. For example, the third saturation temperature loss characteristic 903 can be geometrically determined from the third saturation temperature loss PlsTsat3 for each V2 voltage.

[0163] Furthermore, the EWP loss characteristics 904 shown in Figure 9 represent the power consumption of the electric pump 22 for each V2 voltage; in other words, they represent the power consumption of the electric pump 22 corresponding to each voltage value of V2. For example, information showing the EWP loss characteristics 904 is pre-stored in the memory unit 50b.

[0164] In the second example of use, the control device 50 derives a total loss characteristic 910 based, for example, on the first saturation temperature loss characteristic 901, the second saturation temperature loss characteristic 902, the third saturation temperature loss characteristic 903, and the EWP loss characteristic 904. Here, the total loss characteristic 910 represents the sum of the first saturation temperature loss PlsTsat1, the second saturation temperature loss PlsTsat2, the third saturation temperature loss 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 first saturation temperature loss PlsTsat1, the second saturation temperature loss PlsTsat2, the third saturation temperature loss PlsTsat3, and the power consumption of the electric pump 22, corresponding to the voltage value as V2 voltage.

[0165] The control device 50 then searches for the optimal V2 voltage based on the total loss characteristics 910. More specifically, at this time, the control device 50 searches for the optimal V2 voltage from among the voltage values ​​included in the "applicable V2 voltage range," which is the range of voltage values ​​that can be adopted as the V2 voltage, such that the sum of the first saturation temperature loss PlsTsat1, the second saturation temperature loss PlsTsat2, the third saturation temperature loss PlsTsat3, and the power consumption of the electric pump 22 is minimized. In the example shown in Figure 9, 420[V] is found to be the optimal V2 voltage. The applicable V2 voltage range is predetermined by the manufacturer of the vehicle 1, etc.

[0166] Once the control device 50 has searched for the optimal V2 voltage in this manner, it controls the power converter 10 so that the actual V2 voltage becomes the optimal V2 voltage. This allows the first motor generator MG1 and other components to be operated appropriately with a V2 voltage that takes into account the MOT-INV loss, GEN-INV loss, VCU loss, and the power consumption of the electric pump 22, thereby reducing the power consumption in the vehicle 1.

[0167] In the example described here, the control device 50 searches for the optimal V2 voltage based on the first saturation temperature loss characteristic 901, the second saturation temperature loss characteristic 902, the third saturation temperature loss characteristic 903, and the EWP loss characteristic 904, but it is not limited to this.

[0168] For example, if vehicle 1 is running in EV driving mode, or if vehicle 1 is a BEV and does not have a second motor generator MG2, the control device 50 may search for the optimal V2 voltage based on the first saturation temperature loss characteristic 901, the third saturation temperature loss characteristic 903, and the EWP loss characteristic 904. Furthermore, if the power consumption of the electric pump 22 is sufficiently small compared to the losses of the power converter 10, the control device 50 does not need to use the EWP loss characteristic 904 to search for the optimal V2 voltage. Alternatively, the control device 50 may simply search for the optimal V2 voltage using only one of the first saturation temperature loss characteristic 901, the second saturation temperature loss characteristic 902, and the third saturation temperature loss characteristic 903.

[0169] As described above, in the second example of use, the control device 50 derives the respective loss characteristics Lc (e.g., MOT-INV loss characteristics Lc1d, Lc1e) when the V2 voltage is set to a predetermined first voltage value (e.g., 200[V]) and a predetermined second voltage value (e.g., 350[V]), and based on the respective loss characteristics Lc and thermal resistance characteristics Rc, derives the respective saturation temperature Tsat and saturation temperature loss PlsTsat for the first and second voltage values, and controls the power converter 10 based on the respective saturation temperature loss PlsTsat (e.g., first saturation temperature loss characteristic 901). This makes it possible to control the power converter 10 while considering the saturation temperature loss PlsTsat for each V2 voltage.

[0170] [6. Third usage example] 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 (for example, the vehicle control unit 56) determines the state of the vehicle 1 based on the saturation temperature Tsat. More specifically, in the third application example, the control device 50 determines whether or not there is an abnormality in the device temperature sensor 36 as the state of the vehicle 1 based on the device temperature Tj detected by the device temperature sensor 36 and the saturation temperature Tsat. In the third application example, unless otherwise specified, the saturation temperature Tsat is the saturation temperature Tsat when the first motor generator MG1 etc. is operated under the current operating conditions and the power converter 10 is cooled under the current cooling conditions (for example, the duty cycle of the electric pump 22).

[0171] If the device temperature sensor 36 is functioning correctly, the device temperature Tj detected by the device temperature sensor 36 is expected to stabilize near the saturation temperature Tsat. Therefore, if the device temperature Tj detected by the device temperature sensor 36 deviates from the saturation temperature Tsat for a certain period of time, there is a possibility that an abnormality (e.g., a malfunction) has occurred in the device temperature sensor 36.

[0172] Therefore, in the third example of use, the control device 50 determines that the device temperature sensor 36 is abnormal if the temperature difference between the device temperature Tj and the saturation temperature Tsat detected by the device temperature sensor 36 (hereinafter also referred to as "temperature difference ΔT"), in other words, the value obtained by subtracting the saturation temperature Tsat from the device temperature Tj, remains above a predetermined threshold for a predetermined period Tmx. In other words, the control device 50 determines that the device temperature sensor 36 is normal if the temperature difference ΔT is below the threshold, or if the temperature difference ΔT is above the threshold but only momentarily. This makes it possible for the control device 50 to accurately determine whether or not the device temperature sensor 36 is abnormal based on the saturation temperature Tsat. The above threshold and predetermined period Tmx are set in advance by the manufacturer of the vehicle 1, etc. Furthermore, from the perspective of preventing false detection of abnormalities in the device temperature sensor 36, it is desirable that the control device 50 only determines whether or not the device temperature sensor 36 is abnormal under conditions where the temperature change of the power converter 10 is relatively small, such as when the vehicle 1 is stopped or under low load.

[0173] Figure 10 shows an example of an abnormality detection method for the device temperature sensor 36 in the third use case. In Figure 10 (A), the vertical axis represents the device temperature Tj detected by the device temperature sensor 36, and the horizontal axis represents the time. In Figure 10 (B), the vertical axis represents the temperature difference ΔT, and the horizontal axis represents the time.

[0174] As shown in (B) of Figure 10, in the third application example, a higher fault detection threshold ThH and a lower fault detection threshold ThL (where the lower fault detection threshold ThL < the higher fault detection threshold ThH) are provided as thresholds related to the temperature difference ΔT.

[0175] As an example, suppose the device temperature Tj detected by the device temperature sensor 36 changes as shown by the solid line 1010 in Figure 10 (A), and the temperature difference ΔT changes as shown by the solid line 1011 in Figure 10 (B). In this case, during the period from time t10 to time t11, the temperature difference ΔT is less than the higher failure detection threshold ThH and greater than the lower failure detection threshold ThL, so the control device 50 determines that the device temperature sensor 36 is normal.

[0176] In this case, from time t11, the temperature difference ΔT becomes greater than or equal to the high-temperature fault detection threshold ThH, and even when a predetermined period Tmx has elapsed from time t11 to time t12, the temperature difference ΔT remains greater than or equal to the high-temperature fault detection threshold ThH. When the temperature difference ΔT remains greater than or equal to the high-temperature fault detection threshold ThH for a predetermined period Tmx, the control device 50 determines that a "high-temperature fault" has occurred in the device temperature sensor 36. Here, a high-temperature fault is an abnormality in which the device temperature sensor 36 detects a temperature higher than normal as the device temperature Tj.

[0177] As another example, suppose the device temperature Tj detected by the device temperature sensor 36 changes as shown by the solid line 1020 in Figure 10 (A), and the temperature difference ΔT changes as shown by the solid line 1021 in Figure 10 (B). In this case, during the period from time t10 to time t11, the temperature difference ΔT is less than the higher failure detection threshold ThH and greater than the lower failure detection threshold ThL, so the control device 50 determines that the device temperature sensor 36 is normal.

[0178] In this case, from time t11, the temperature difference ΔT is below the low-fault detection threshold ThL, and even when a predetermined period Tmx has elapsed from time t11 to time t12, the temperature difference ΔT remains below the low-fault detection threshold ThL. When the temperature difference ΔT remains below the low-fault detection threshold ThL for a predetermined period Tmx, the control device 50 determines that a "low-fault" has occurred in the device temperature sensor 36. Here, a low-fault is an abnormality in which the device temperature sensor 36 detects a temperature lower than normal as the device temperature Tj.

[0179] As described above, in the third use case, the control device 50 determines whether the device temperature sensor 36 is abnormal based on the device temperature Tj and saturation temperature Tsat detected by the device temperature sensor 36. This makes it possible to accurately determine whether the device temperature sensor 36 is abnormal.

[0180] In the third example of use, if the control device 50 determines that an abnormality has occurred in the device temperature sensor 36, it may, for example, notify the occupants of vehicle 1 of the abnormality in the device temperature sensor 36 via an unillustrated notification device (e.g., a display) provided in vehicle 1. In this way, it becomes possible to prompt the occupants of vehicle 1 to have vehicle 1 inspected.

[0181] (A variation of the third example of use) Next, a modified example of the third use case will be described. The modified example described below is an example in which 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, are provided, and the control device 50 determines whether or not there is an abnormality in the water temperature sensor 35 based on the device temperature Tj and saturation temperature Tsat detected by each of these sensors. In the following description, the focus will be on the differences from the example described above, and the explanation of parts that are the same as the example described above will be omitted or simplified as appropriate.

[0182] In this modified example, the device temperature Tj detected by the first device temperature sensor 36a is also called the "first device temperature," and the temperature difference between the first device temperature and the saturation temperature Tsat is also called the "temperature difference ΔTa." The device temperature Tj detected by the second device temperature sensor 36b is also called the "second device temperature," and the temperature difference between the second device temperature and the saturation temperature Tsat is also called the "temperature difference ΔTb." The device temperature Tj detected by the third device temperature sensor 36c is also called the "third device temperature," and the temperature difference between the third device temperature and the saturation temperature Tsat is also called the "temperature difference ΔTc."

[0183] Furthermore, in this modified example, the first abnormality in device temperature refers, for example, to a temperature difference ΔTa that is greater than or equal to the higher failure threshold ThH, or less than or equal to the lower failure threshold ThL. The second abnormality in device temperature refers, for example, to a temperature difference ΔTb that is greater than or equal to the higher failure threshold ThH, or less than or equal to the lower failure threshold ThL. The third abnormality in device temperature refers, for example, to a temperature difference ΔTc that is greater than or equal to the higher failure threshold ThH, or less than or equal to the lower failure threshold ThL.

[0184] Figure 11 shows an example of a decision made by the control device 50 according to the temperature state of each device in a modified example of the third use case. As shown in Table 1100 of Figure 11, in this modified example, if "State A-1", "State A-2", or "State A-3" occurs, in which only one of the first device temperature, second device temperature, and third device temperature is abnormal, and that state continues for a predetermined period Tmx, the control device 50 determines that an abnormality has occurred in the device temperature sensor that detected that device temperature.

[0185] Furthermore, as shown in Table 1100 in Figure 11, if "State B-1," "State B-2," or "State B-3" occurs, where two of the first, second, and third device temperatures are abnormal and the other device temperature is normal, the control device 50 does not determine that an abnormality has occurred in each of the device temperature sensors 36a, 36b, and 36c, but rather considers that it is still determining the abnormality of the water temperature sensor 35. This is because it is considered unlikely that abnormalities in two of the first, second, and third device temperature sensors 36a, 36b, and 36c will occur at the same time.

[0186] Then, as shown in Table 1100 in Figure 11, if "State C" occurs where the temperature of the first device, the temperature of the second device, and the temperature of the third device are all abnormal, and this state continues for a predetermined period Tmx, the control device 50 determines that an abnormality has occurred in the water temperature sensor 35. In other words, when "State C" occurs, it is more likely that the value of the water temperature TW used to derive the saturation temperature Tsat is abnormal, i.e., that an abnormality has occurred in the water temperature sensor 35, than that an abnormality has occurred in each of the device temperature sensors 36a, 36b, and 36c. Therefore, when "State C" occurs, the control device 50 determines that an abnormality has occurred in the water temperature sensor 35, thereby suppressing false detection of abnormalities in each of the device temperature sensors 36a, 36b, and 36c, and enabling accurate detection of abnormalities in the water temperature sensor 35.

[0187] Figure 12 shows an example of a method for detecting abnormalities in a water temperature sensor in a modified example of the third application. In Figure 12 (A), the vertical axis represents the temperature difference ΔTa, and the horizontal axis represents the time period. In Figure 12 (B), the vertical axis represents the temperature difference ΔTb, and the horizontal axis represents the time period. In Figure 12 (C), the vertical axis represents the temperature difference ΔTc, and the horizontal axis represents the time period.

[0188] In the example shown in Figure 12, from time t21, only the temperature difference ΔTa became greater than or equal to the higher fault detection threshold ThH, so the control device 50 determines the state of vehicle 1 to be "state A-1". Subsequently, from time t22, before a predetermined period Tmx has elapsed from time t21, the temperature difference ΔTb also became greater than or equal to the higher fault detection threshold ThH, so the control device 50 determines the state of vehicle 1 to be "state B-1".

[0189] Then, from time t23 after time t22, the temperature difference ΔTc also became higher than the high fault detection threshold ThH, so the control device 50 determines that the state of vehicle 1 is "state C". Subsequently, even when a predetermined period Tmx has elapsed from time t23 to time t24, the temperature differences ΔTa, ΔTb, and ΔTc remain higher than the high fault detection threshold ThH. In this way, if the state in which the temperature differences ΔTa, ΔTb, and ΔTc are higher than the high fault detection threshold ThH (i.e., "state C") continues for a predetermined period Tmx, the control device 50 determines that an abnormality has occurred in the water temperature sensor 35.

[0190] In the example described here, the control device 50 determines that an abnormality has occurred in the water temperature sensor 35 when the state of vehicle 1 is "state C," but this is not the only option. For example, the control device 50 may also determine that an abnormality has occurred in the water temperature sensor 35 when the state of vehicle 1 is "state B-1," "state B-2," or "state B-3."

[0191] 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, but is not limited to this. For example, two device temperature sensors 36 may be provided, and the control device 50 may determine that an abnormality has occurred in the water temperature sensor 35 if the device temperatures corresponding to each of these sensors are abnormal. Alternatively, four or more device temperature sensors 36 may be provided, and the control device 50 may determine that an abnormality has occurred in the water temperature sensor 35 if the device temperatures corresponding to each of these sensors are abnormal, or if two or more predetermined device temperatures are abnormal.

[0192] As described above, in this modified example, the control device 50 determines whether the water temperature sensor 35 is abnormal based on the device temperature Tj and saturation temperature Tsat detected by each device temperature sensor. This makes it possible to accurately determine whether the water temperature sensor 35 is abnormal.

[0193] [7. Fourth usage example] Next, a fourth application example of the present invention will be described. This fourth application example is one in which the control device 50 (for example, the 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.

[0194] Figure 13 shows an example of a vehicle control method in the fourth use case. As shown in Figure 13, in the fourth use case, a cooling priority threshold and a warming priority threshold are provided as thresholds set based on the device temperature Tj detected by the device temperature sensor 36. For example, the control device 50 sets the temperature obtained by adding a predetermined value greater than 0 to the device temperature Tj as the cooling priority threshold, and sets the temperature obtained by subtracting a predetermined value greater than 0 from the device temperature Tj as the warming priority threshold. Here, the predetermined values ​​are determined in advance by the manufacturer of the vehicle 1, etc.

[0195] As shown in Figure 13, in the fourth use case, when the saturation temperature Tsat is lower than the cooling priority threshold and higher than the warm-up priority threshold, that is, when the vehicle 1 is in a medium-load state, the control device 50 determines the state of the vehicle 1 as "pattern α" and executes efficiency-prioritizing control. In efficiency-prioritizing control, the control device 50 optimizes the efficiency in the vehicle 1 by, for example, controlling the electric pump 22 with the optimal Duty cycle found as described in the first use case, or controlling the power converter 10 with the optimal V2 voltage found as described in the second use case.

[0196] Furthermore, if the saturation temperature Tsat is above the cooling priority threshold, that is, if vehicle 1 is under high load, the control device 50 determines the state of vehicle 1 as "pattern β" and executes cooling priority control. In cooling priority control, the control device 50 suppresses the temperature rise of the power converter 10 by increasing the duty cycle of the electric pump 22 from its current level. At this time, the control device 50 may set the duty cycle of the electric pump 22 to the maximum value within the applicable duty cycle range.

[0197] Furthermore, if the saturation temperature Tsat is below the warm-up priority threshold, that is, if vehicle 1 is in a low-load state, the control device 50 determines the state of vehicle 1 as "pattern γ" and executes warm-up priority control. In warm-up priority control, the control device 50 promotes the temperature rise of the power converter 10 by reducing the duty cycle of the electric pump 22 from its current value. At this time, the control device 50 may set the duty cycle of the electric pump 22 to the minimum value within the applicable duty cycle range.

[0198] As described above, in the fourth example of use, the control device 50 determines the load state of the vehicle 1 based on the device temperature Tj and saturation temperature Tsat detected by the device temperature sensor 36, and controls the vehicle 1 based on the determination result, thereby enabling appropriate control of the vehicle 1 while taking into account the load state of the vehicle 1.

[0199] In the embodiments described above, an example was given in which the control device of the present invention is implemented by a control device 50 mounted on a vehicle 1, but the invention is not limited to this. For example, the control device of the present invention may be implemented by a server that can communicate with the control device 50. In this case, for example, each of the processes of the control device 50 described above may be performed by a processing unit implemented by the CPU or the like of the server. Furthermore, the control device of the present invention may be implemented by the cooperation of the control device 50 and the server, and for example, some of the processes of the control device 50 described above may be executed by the server.

[0200] Furthermore, the control method described in the above-mentioned embodiment can be realized by executing a pre-prepared program on a computer (in other words, a processor). This program (control program) is stored on a computer-readable storage medium and executed by being read from the storage medium. This program may also be provided in the form of a non-volatile (non-transient) storage medium such as flash memory, or it may be provided via a network such as the Internet. The computer that executes this program may be included in vehicle 1, or it may be included in an external device (e.g., a server) that can communicate with vehicle 1.

[0201] Although one embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to this embodiment. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention.

[0202] For example, in the embodiments described above, the mobile body in the present invention was a hybrid electric vehicle (vehicle 1), but it is not limited to this. For example, the mobile body in the present invention may be a BEV (battery electric vehicle), an eVTOL (electric vertical take-off and landing aircraft), or a drone (unmanned aerial vehicle).

[0203] This specification contains at least the following information. Note that the components, etc., in parentheses indicate the corresponding components in the above embodiments, but are not limited thereto.

[0204] (1) A control method executed by a computer (control device 50) that controls a mobile body (vehicle 1) comprising a motor generator (first motor generator MG1, second motor generator MG2), a power conversion device (power conversion device 10, first inverter 11, second inverter 12, voltage conversion device 13) that exchanges power with the motor generator, and a cooling device (cooling device 20) that cools the power conversion device, The aforementioned computer, Based on the operating conditions of the motor generator, the loss characteristics (loss characteristics Lc) representing the temperature-dependent losses of the power converter when the motor generator is operated under those operating conditions are derived (step Sp3). Based on the cooling conditions of the power converter by the cooling device, the thermal resistance (thermal resistance Rt) of the power converter when the power converter is cooled under those cooling conditions is derived (step Sp5). Based on the loss characteristics and the thermal resistance, a thermal resistance characteristic (thermal resistance characteristic Rc) representing the temperature reached for each loss in the power converter is derived (step Sp6). Based on the loss characteristics and the thermal resistance characteristics, the saturation temperature (saturation temperature Tsat), which is the temperature reached by the power converter when the motor generator is operated under the operating conditions and the power converter is cooled under the cooling conditions, and the loss at saturation temperature (loss at saturation temperature PlsTsat), which is the loss of the power converter at that saturation temperature, are derived (step Sp7). Based on the saturation temperature and / or the loss at the saturation temperature, the moving body is controlled (step Sp8). A control method for performing processing.

[0205] According to (1), when the motor generator is operated under predetermined operating conditions and the power converter is cooled under predetermined cooling conditions, the saturation temperature and the loss at saturation temperature can be derived, making it possible to control the mobile body taking into account the saturation temperature and / or loss at saturation temperature. This, in turn, can contribute to improving the energy efficiency of the mobile body.

[0206] (2) The control method described in (1), The aforementioned computer, On a plane in which the loss of the power converter is plotted on one axis and the temperature of the power converter is plotted on the other axis, the loss of the power converter corresponding to the intersection point (intersection CP) of the loss characteristic and the thermal resistance characteristic is derived as the loss at saturation temperature, and the temperature of the power converter corresponding to the intersection point is derived as the saturation temperature. Control method.

[0207] According to (2), the saturation temperature and the loss at saturation temperature can be determined with high accuracy by simple calculations.

[0208] (3) A control method described in (1) or (2), The aforementioned computer, The loss characteristics are derived based on the operating conditions, namely the rotational speed (MOT rotational speed, GEN rotational speed) and output torque (MOT torque, GEN torque) of the motor generator, and the voltage value (V2 voltage) of the power exchanged between the motor generator and the power converter. Control method.

[0209] According to (3), it is possible to derive loss characteristics that take into account the rotational speed and output torque of the motor generator and the voltage value of the power exchanged between the motor generator and the power converter.

[0210] (4) The control method described in (3), The aforementioned computer, The loss characteristics are derived for the cases where the voltage value is a predetermined first voltage value and for the case where a predetermined second voltage value different from the first voltage value is used. Based on the respective loss characteristics and thermal resistance characteristics, the saturation temperature and loss at the saturation temperature are derived for the first voltage value and the second voltage value, respectively. Based on the respective losses at saturation temperature, the power converter is controlled. Control method.

[0211] According to (4), it becomes possible to control the power converter while taking into account the saturation temperature loss for each voltage value of the power exchanged between the motor generator and the power converter.

[0212] (5) A control method described in (1) or (2), The cooling device comprises a cooling circuit (cooling circuit 21) through which cooling water circulates, and an electric pump (electric pump 22) that pressurizes and pumps the cooling water through the cooling circuit. The mobile body is equipped with a water temperature sensor (water temperature sensor 35) for detecting the temperature of the cooling water. The aforementioned computer, As the cooling conditions, based on the temperature of the cooling water detected by the water temperature sensor (water temperature TW) and the operating state of the electric pump (Duty), the flow rate of the cooling water pumped per unit time (flow rate Fw) by the electric pump is derived (step Sp4). Based on the flow rate, the thermal resistance is derived. Control method.

[0213] According to (5), it is possible to appropriately derive the thermal resistance of the power converter without having to install a flow sensor to detect the flow rate of the cooling water pumped by the electric pump.

[0214] (6) The control method described in (5), The aforementioned computer, The flow rates are derived for each case where the operating state of the electric pump is set to a predetermined first state and for each case where it is set to a predetermined second state different from the first state. Based on the respective flow rates, the 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 thermal resistances, the saturation temperature and the loss at the saturation temperature for the first state and the second state are derived, Based on the respective losses at saturation temperature, the electric pump is controlled. Control method.

[0215] According to (6), it becomes possible to control the electric pump while taking into account the loss at saturation temperature for each flow rate of cooling water pumped by the electric pump.

[0216] (7) A control method described in (1) or (2), The mobile body is equipped with a device temperature sensor (device temperature sensor 36) for detecting the temperature of the power converter, The aforementioned computer, Based on the temperature of the power converter detected by the device temperature sensor and the saturation temperature, it is determined whether or not the device temperature sensor is malfunctioning. Control method.

[0217] According to (7), it becomes possible to accurately determine whether or not the device temperature sensor that detects the temperature of the power converter is malfunctioning.

[0218] (8) A control method as described in (1) or (2), The cooling device includes a cooling circuit (cooling circuit 21) through which cooling water circulates. The mobile body includes a water temperature sensor (water temperature sensor 35) for detecting the temperature of the cooling water and a plurality of device temperature sensors (first device temperature sensor 36a, second device temperature sensor 36b, third device temperature sensor 36c) for detecting the temperature of the power converter. The aforementioned computer, Based on the temperature of the power converter detected by each of the device temperature sensors and the saturation temperature, it is determined whether or not the water temperature sensor is malfunctioning. Control method.

[0219] According to (8), it is possible to accurately determine whether or not the water temperature sensor that detects the temperature of the cooling water circulating in the cooling circuit is malfunctioning.

[0220] (9) A control method as described in (1) or (2), The mobile body is equipped with a device temperature sensor (device temperature sensor 36) for detecting the temperature of the power converter, The aforementioned computer, Based on the temperature of the power converter detected by the device temperature sensor and the saturation temperature, the load state of the mobile body is determined, and the mobile body is controlled based on the determination result. Control method.

[0221] According to (9), it becomes possible to appropriately control the moving body by taking into account the load condition of the moving body.

[0222] (10) A control method as described in (1) or (2), The moving body is equipped with a plurality of motor generators (first motor generator MG1, second motor generator MG2) as the motor generator, The aforementioned computer, For each of the motor generators, the saturation temperature and the loss at the saturation temperature are derived. Control method.

[0223] According to (10), even when the mobile body is equipped with multiple motor generators, it is possible to control the mobile body while taking into account the saturation temperature and / or saturation temperature loss corresponding to each motor generator.

[0224] (11) A control device (control device 50) for controlling a mobile body (vehicle 1) comprising a motor generator (first motor generator MG1, second motor generator MG2), a power conversion device (power conversion device 10, first inverter 11, second inverter 12, voltage conversion device 13) that exchanges power with the motor generator, and a cooling device (cooling device 20) that cools the power conversion device, A loss characteristic derivation unit (loss characteristic derivation unit 51) derives a loss characteristic (loss characteristic Lc) that represents the temperature-dependent loss of the power converter when the motor generator is operated under the operating conditions of the motor generator, based on the operating conditions of the motor generator, A thermal resistance derivation unit (thermal resistance derivation unit 53) derives the thermal resistance (thermal resistance Rt) of the power converter when the power converter is cooled under the cooling conditions of the cooling device, based on the cooling conditions of the power converter by the cooling device, A thermal resistance characteristic derivation unit (thermal resistance characteristic derivation unit 54) derives a thermal resistance characteristic (thermal resistance characteristic Rc) that represents the temperature reached for each loss in the power conversion device, based on the loss characteristics derived by the loss characteristic derivation unit and the thermal resistance derived by the thermal resistance derivation unit. A saturation temperature / saturation temperature loss derivation unit (saturation temperature / saturation temperature loss derivation unit 55) derives, based on the loss characteristics and the thermal resistance characteristics derived by the thermal resistance characteristic derivation unit, the saturation temperature (saturation temperature Tsat), which is the temperature reached by the power converter when the motor generator is operated under the operating conditions and the power converter is cooled under the cooling conditions, and the saturation temperature loss (saturation temperature loss PlsTsat), which is the loss of the power converter at that saturation temperature, Based on the saturation temperature and / or the loss at saturation temperature derived by the saturation temperature and loss at saturation temperature derivation unit, a mobile body control unit (vehicle control unit 56) controls the mobile body, A control device equipped with the following features.

[0225] According to (11), when the motor generator is operated under predetermined operating conditions and the power converter is cooled under predetermined cooling conditions, the saturation temperature and the loss at saturation temperature can be derived, making it possible to control the mobile body taking into account the saturation temperature and / or loss at saturation temperature. This can, in turn, contribute to improving the energy efficiency of the mobile body.

[0226] (12) A control program that causes a computer (control device 50) that controls a mobile body (vehicle 1) comprising a motor generator (first motor generator MG1, second motor generator MG2), a power conversion device (power conversion device 10, first inverter 11, second inverter 12, voltage conversion device 13) that exchanges power with the motor generator, and a cooling device (cooling device 20) that cools the power conversion device, to execute a predetermined process, To the aforementioned computer, Based on the operating conditions of the motor generator, the loss characteristics (loss characteristics Lc) representing the temperature-dependent losses of the power converter when the motor generator is operated under those operating conditions are derived (step Sp3). Based on the cooling conditions of the power converter by the cooling device, the thermal resistance (thermal resistance Rt) of the power converter when the power converter is cooled under those cooling conditions is derived (step Sp5). Based on the loss characteristics and the thermal resistance, a thermal resistance characteristic (thermal resistance characteristic Rc) representing the temperature reached for each loss in the power converter is derived (step Sp6). Based on the loss characteristics and the thermal resistance characteristics, the saturation temperature (saturation temperature Tsat), which is the temperature reached by the power converter when the motor generator is operated under the operating conditions and the power converter is cooled under the cooling conditions, and the loss at saturation temperature (loss at saturation temperature PlsTsat), which is the loss of the power converter at that saturation temperature, are derived (step Sp7). Based on the saturation temperature and / or the loss at the saturation temperature, the moving body is controlled (step Sp8). A control program that executes a process.

[0227] According to (12), when the motor generator is operated under predetermined operating conditions and the power converter is cooled under predetermined cooling conditions, the saturation temperature and the loss at saturation temperature can be derived, making it possible to control the mobile body taking into account the saturation temperature and / or loss at saturation temperature. This can, in turn, contribute to improving the energy efficiency of the mobile body. [Explanation of symbols]

[0228] 1. Vehicle (mobile object) 10 Power converter 11. First Inverter (Power Converter) 12. Second Inverter (Power Converter) 13. Voltage converter (power converter) 20 Cooling device 21 Cooling circuit 22 Electric pump 35. Water temperature sensor 36 Device Temperature Sensors 36a First device temperature sensor 36b Second device temperature sensor 36c Third Device Temperature Sensor 50 Control device 51 Loss characteristic derivation part 52 Flow rate derivation part 53 Thermal resistance derivation section 54 Thermal resistance characteristic derivation section 55 Saturation temperature / Loss derivation section at saturation temperature 56 Vehicle Control Unit (Mobile Unit Control Unit) CP intersection Lc loss characteristics PlsTsat Loss at saturation temperature RC thermal resistance characteristics Tsat saturation temperature

Claims

1. A control method performed by a computer that controls a mobile body comprising a motor generator, a power converter that exchanges power with the motor generator, and a cooling device that cools the power converter, The aforementioned computer, Based on the operating conditions of the motor generator, the loss characteristics representing the temperature-dependent losses of the power converter when the motor generator is operated under those operating conditions are derived. Based on the cooling conditions of the power converter by the cooling device, the thermal resistance of the power converter when the power converter is cooled under those cooling conditions is derived. Based on the loss characteristics and the thermal resistance, a thermal resistance characteristic representing the temperature reached for each loss in the power converter is derived. Based on the loss characteristics and the thermal resistance characteristics, the saturation temperature, which is the temperature reached by the power converter when the motor generator is operated under the operating conditions and the power converter is cooled under the cooling conditions, and the loss at saturation temperature, which is the loss of the power converter at that saturation temperature, are derived. Based on the saturation temperature and / or the loss at the saturation temperature, the moving body is controlled. A control method for performing processing.

2. A control method according to claim 1, The aforementioned computer, On a plane in which the loss of the power converter is plotted on one axis and the temperature of the power converter is plotted on the other axis, the loss of the power converter corresponding to the intersection of the loss characteristics and the thermal resistance characteristics is derived as the loss at saturation temperature, and the temperature of the power converter corresponding to the intersection is derived as the saturation temperature. Control method.

3. A control method according to claim 1 or 2, The aforementioned computer, The loss characteristics are derived based on the operating conditions, namely the rotational speed and output torque of the motor-generator and the voltage value of the power exchanged between the motor-generator and the power converter. Control method.

4. A control method according to claim 3, The aforementioned computer, The loss characteristics are derived for the cases where the voltage value is a predetermined first voltage value and for the case where a predetermined second voltage value different from the first voltage value is used. Based on the respective loss characteristics and thermal resistance characteristics, the saturation temperature and loss at the saturation temperature are derived for the first voltage value and the second voltage value, respectively. Based on the respective losses at saturation temperature, the power converter is controlled. Control method.

5. A control method according to claim 1 or 2, The cooling device comprises a cooling circuit through which cooling water circulates, and an electric pump that pressurizes and pumps the cooling water through the cooling circuit. The mobile body is equipped with a water temperature sensor for detecting the temperature of the cooling water, The aforementioned computer, As the cooling conditions, the flow rate of the cooling water pumped per unit time by the electric pump is derived based on the temperature of the cooling water detected by the water temperature sensor and the operating state of the electric pump. Based on the flow rate, the thermal resistance is derived. Control method.

6. A control method according to claim 5, The aforementioned computer, The flow rates are derived for each case where the operating state of the electric pump is set to a predetermined first state and for each case where it is set to a predetermined second state different from the first state. Based on the respective flow rates, the 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 thermal resistances, the saturation temperature and the loss at the saturation temperature for the first state and the second state are derived, Based on the respective losses at saturation temperature, the electric pump is controlled. Control method.

7. A control method according to claim 1 or 2, The mobile body includes a device temperature sensor for detecting the temperature of the power converter, The aforementioned computer, Based on the temperature of the power converter detected by the device temperature sensor and the saturation temperature, it is determined whether or not the device temperature sensor is malfunctioning. Control method.

8. A control method according to claim 1 or 2, The cooling device includes a cooling circuit through which cooling water circulates. The mobile body comprises a water temperature sensor for detecting the temperature of the cooling water and a plurality of device temperature sensors for detecting the temperature of the power converter. The aforementioned computer, Based on the temperature of the power converter detected by each of the device temperature sensors and the saturation temperature, it is determined whether or not the water temperature sensor is malfunctioning. Control method.

9. A control method according to claim 1 or 2, The mobile body includes a device temperature sensor for detecting the temperature of the power converter, The aforementioned computer, Based on the temperature of the power converter detected by the device temperature sensor and the saturation temperature, the load state of the mobile body is determined, and the mobile body is controlled based on the determination result. Control method.

10. A control method according to claim 1 or 2, The moving body is equipped with a plurality of motor generators as the motor generator, The aforementioned computer, For each of the motor generators, the saturation temperature and the loss at the saturation temperature are derived. Control method.

11. A control device for controlling a mobile body comprising a motor generator, a power converter that exchanges power with the motor generator, and a cooling device that cools the power converter, A loss characteristic derivation unit that derives loss characteristics representing the temperature-dependent losses of the power converter when the motor generator is operated under the operating conditions of the motor generator, based on the operating conditions of the motor generator, A thermal resistance derivation unit that derives the thermal resistance of the power converter when the power converter is cooled under the cooling conditions of the cooling device, based on the cooling conditions of the power converter by the cooling device, A thermal resistance characteristic derivation unit derives a thermal resistance characteristic representing the temperature reached for each loss in the power converter, based on the loss characteristics derived by the loss characteristic derivation unit and the thermal resistance derived by the thermal resistance derivation unit. A saturation temperature / saturation temperature loss derivation unit derives, based on the loss characteristics and the thermal resistance characteristics derived by the thermal resistance characteristic derivation unit, the saturation temperature which is the temperature reached by the power converter when the motor generator is operated under the operating conditions and the power converter is cooled under the cooling conditions, and the saturation temperature loss which is the loss of the power converter when it is at the saturation temperature. Based on the saturation temperature and / or saturation temperature loss derived by the saturation temperature and saturation temperature loss derivation unit, a mobile body control unit controls the mobile body, A control device equipped with the following features.

12. A control program that causes a computer controlling a mobile body comprising a motor generator, a power converter that exchanges power with the motor generator, and a cooling device that cools the power converter to perform a predetermined process, To the aforementioned computer, Based on the operating conditions of the motor generator, the loss characteristics representing the temperature-dependent losses of the power converter when the motor generator is operated under those operating conditions are derived. Based on the cooling conditions of the power converter by the cooling device, the thermal resistance of the power converter when the power converter is cooled under those cooling conditions is derived. Based on the loss characteristics and the thermal resistance, a thermal resistance characteristic representing the temperature reached for each loss in the power converter is derived. Based on the loss characteristics and the thermal resistance characteristics, the saturation temperature, which is the temperature reached by the power converter when the motor generator is operated under the operating conditions and the power converter is cooled under the cooling conditions, and the loss at saturation temperature, which is the loss of the power converter at that saturation temperature, are derived. Based on the saturation temperature and / or the loss at the saturation temperature, the moving body is controlled. A control program that executes a process.

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