Drive device for electric vehicle, having electric machine with three-phase coil, electrical storage device and inverter, configured to operate in three-phase mode and two-phase mode

Abstract

The driving device includes a motor having a three-phase coil, an electrical storage device, and an inverter configured to convert a direct current from the electrical storage device into a three-phase alternating current and supply the three-phase alternating current to the motor. The driving device is programmed to execute a first mode of driving all three phases of the inverter or a second mode of driving two phases of the three phases of the inverter during at least one of external charging and external power supply, power supplied from an external power supply device to a neutral point to which the three-phase coil is connected is supplied to the power storage device by voltage conversion by the motor and the inverter, and in external power supply, power from the power storage device is supplied to the outside of the driving device via the neutral point by voltage conversion by the inverter and the motor.

Description

Technical Field

[0001] The present disclosure relates to a drive device. Background Art

[0002] A configuration of a drive device including a motor having a three-phase coil, a power storage device, and an inverter that converts direct current from the power storage device into three-phase alternating current and supplies it to the motor has been proposed (for example, see Patent Documents 1 and 2). The drive device of Patent Document 1 controls the inverter by setting the duty cycle value of the inverter's switching elements during external charging. During external charging, the power supplied from the external power supply device to the neutral point to which the three-phase coil is connected is converted in voltage by the motor and the inverter and supplied to the power storage device. The drive device of Patent Document 2 also controls the inverter during external charging by setting one of the three-phase currents of the motor to zero based on the rotor angle of the motor and setting the currents of the remaining two phases so that the torque of the motor is zero. Reference List Patent Literature

[0003] [Patent Document 1] US2020 / 0177014 [Patent Document 2] US2020 / 0189409 Summary of the Invention Technical issues

[0004] In the drive device described in Patent Document 1, during at least one of external charging or external power supply (in external power supply, power from a power storage device is supplied to the outside of the drive device via the neutral point of the motor through voltage conversion between the inverter and the motor), if the drive device always operates in a first mode in which all three phases of the inverter are driven, the heat generated by the motor tends to increase. On the other hand, in the drive device described in Patent Document 2, during at least one of external charging and external power supply, if the drive device always operates in a second mode in which two of the three phases of the inverter are driven, the heat generated by the inverter tends to increase. Based on these considerations, it is necessary to more appropriately execute at least one of external charging and external power supply.

[0005] A main object of the driving device of the present disclosure is to more appropriately perform at least one of external charging and external power supply. Solution to the problem

[0006] In order to achieve the above-mentioned main object, the driving device of the present disclosure adopts the following configuration.

[0007] A drive device disclosed herein includes a motor having three-phase coils, a power storage device, and an inverter configured to convert direct current (DC) power from the power storage device into three-phase AC power and supply the three-phase AC power to the motor. The drive device is programmed to operate in a first mode in which all three phases of the inverter are driven, or a second mode in which two of the three phases of the inverter are driven, during at least one of external charging and external power supply. During external charging, power supplied from an external power supply device to a neutral point to which the three-phase coils are connected is supplied to the power storage device through voltage conversion by the motor and inverter. During external power supply, power from the power storage device is supplied to the outside of the drive device via the neutral point through voltage conversion by the inverter and motor.

[0008] The drive device of the present disclosure operates in a first mode, driving all three phases of the inverter, or a second mode, driving two of the three phases of the inverter, during at least one of external charging and external power supply. During external charging, power supplied from an external power supply device to the neutral point to which the three-phase coils are connected is supplied to the power storage device through voltage conversion by the motor and inverter. During external power supply, power from the power storage device is supplied to the outside of the drive device via the neutral point through voltage conversion by the inverter and motor. This configuration enables more appropriate execution of at least one of external charging and external power supply.

[0009] In the drive device of the present disclosure, the drive device can be configured to execute the first mode or the second mode based on at least one of information related to the motor, information related to the inverter, information related to the power storage device, information related to the neutral point, and information related to the external environment. Therefore, the drive device can execute the first mode or the second mode based on at least one of the various types of information. The information related to the motor includes the temperature of the motor. The information related to the inverter includes the temperature of the inverter. The information related to the power storage device includes the temperature of the power storage device. The information related to the neutral point includes the power and current from the external power supply device to the neutral point. When the drive device includes a heater that uses the motor and the inverter as a heat source to heat the vehicle cabin, the temperature related to the external environment includes whether there is a heating demand and the temperature inside the vehicle cabin.

[0010] In the drive device of the above aspect that performs the first mode or the second mode based on at least one of various types of information, the drive device can be programmed to perform staggered driving in the second mode when the supply-related value of the power or current supplied from the external power supply device to the neutral point is equal to or less than the supply threshold, and to perform staggered driving in the first mode when the supply-related value is greater than the supply threshold. In the staggered driving of the first mode, the inverter is driven so that the phases of the three-phase current of the motor are offset by 120 degrees from each other. For example, in the staggered driving of the first mode, the phases of the three-phase current of the motor can be offset by 120 degrees from each other by offsetting the phases of the respective phase carriers (e.g., triangular waves, sawtooth waves, inverse sawtooth waves, etc.) in the duty cycle control of the three-phase switching elements of the inverter by 120 degrees. In the staggered driving of the second mode, the inverter is driven so that the phases of the two-phase current of the motor are offset by 180 degrees from each other. For example, in the second mode of interleaved drive, the phases of the two-phase currents of the motor can be offset by 180 degrees by shifting the phases of the carrier waves in the duty cycle control of the switching elements of the two phases of the inverter by 180 degrees. The inventors have confirmed the following through experiments, analysis, and machine learning. When the supply-related value is small, the entire drive unit, including the motor and inverter, generates more heat and the efficiency of external charging is lower when interleaved drive is performed in the first mode than when interleaved drive is performed in the second mode. On the other hand, when the supply-related value is high, the entire drive unit generates more heat and the efficiency of external charging is lower when interleaved drive is performed in the second mode than when interleaved drive is performed in the first mode. Accordingly, when the supply-related value is equal to or less than the supply threshold, the drive device performs interleaved drive in the second mode, and when the supply-related value is greater than the supply threshold, the drive device performs interleaved drive in the first mode. This configuration suppresses the heat generated by the entire drive unit. Therefore, efficient external charging can be achieved.

[0011] In the drive device of the above aspect that performs staggered drive in the first mode or the second mode based on the supply-related value, the drive device may further include a cooler configured to circulate a cooling medium through the motor, inverter, and power storage device. The drive device may be programmed to perform staggered drive in the first mode when the power storage device is required to heat up and the supply-related value is less than a supply threshold, and to perform staggered drive in the second mode when the power storage device is required to heat up and the supply-related value is equal to or greater than the supply threshold. This configuration increases the heat generated by the entire drive unit, thereby accelerating the temperature rise of the power storage device.

[0012] In the drive device of the above aspect that performs staggered driving in a first mode or a second mode based on a supply-related value, the drive device may further include a heater configured to heat the vehicle cabin using a motor and an inverter as a heat source. The drive device can be programmed to perform staggered driving in the first mode when cabin heating is requested and the supply-related value is less than a supply threshold, and to perform staggered driving in the second mode when cabin heating is requested and the supply-related value is equal to or greater than the supply threshold. This configuration increases the heat generated by the entire drive unit. As a result, the cabin is more fully heated.

[0013] In the drive device of the aforementioned aspect that executes the first mode or the second mode based on at least one of various types of information, the drive device may be programmed to execute interleaved driving in the first mode when the temperature of the inverter is greater than a second temperature threshold. This configuration suppresses further increases in the inverter temperature.

[0014] In the drive device of the above aspect that executes the first mode or the second mode based on at least one of various types of information, the drive device may be programmed to execute staggered drive in the first mode when the temperature of the motor is greater than a first temperature threshold, the temperature of the inverter is greater than a second temperature threshold, and the inverter is heating more severely than the motor. This configuration suppresses further increases in the inverter temperature when the inverter is heating more severely than the motor.

[0015] In the drive device of the above aspect that executes the first mode or the second mode based on at least one of the various types of information, the drive device may be programmed to instruct the external power supply device to limit the power or current from the external power supply device to the neutral point when the temperature of the motor is greater than the first temperature threshold and / or the temperature of the inverter is greater than the second temperature threshold, compared to when the temperature of the motor is equal to or less than the first temperature threshold and the temperature of the inverter is equal to or less than the second temperature threshold. This configuration suppresses further increases in the temperature of the motor and the inverter when the temperature of the motor is greater than the first temperature threshold and / or the temperature of the inverter is greater than the second temperature threshold.

[0016] The drive device of the present disclosure can be programmed to perform interleaved drive in either the first mode or the second mode. Furthermore, in the second mode, the drive device can be programmed to perform interleaved drive using two drive phases, the two phases with the smallest difference in inductance among the three phases. This configuration reduces heat generation in the motor when performing interleaved drive in the second mode. Consequently, efficient external charging can be achieved.

[0017] In the drive device of the above aspect that uses two drive phases to perform interleaved drive in the second mode, the drive device may further include a cooler configured to circulate a cooling medium through the motor, inverter, and power storage device. The drive device may be programmed to perform interleaved drive in the second mode using two drive phases, the two phases having the largest difference in inductance among the three phases, when the power storage device is required to heat up. This configuration increases the heat generated by the motor when performing interleaved drive in the second mode, thereby accelerating the temperature increase of the power storage device.

[0018] In the drive device of the aforementioned aspect that uses two drive phases for interleaved drive in the second mode, the drive device may further include a heater configured to heat the vehicle cabin using the motor and inverter as heat sources. The drive device can be programmed to use two drive phases with the largest difference in inductance among the three phases in the second mode when heating of the vehicle cabin is required. This configuration increases the motor's heating during interleaved drive in the second mode, thereby more effectively heating the vehicle cabin.

[0019] In the drive device of the above aspect that performs interleaved driving using the driving two phases in the second mode, the drive device may be programmed to set the driving two phases based on the rotational position of the rotor of the motor. This configuration sets the driving two phases more appropriately.

[0020] In the drive device of the above aspect using the second mode for driving two phases, the drive device can be programmed to set the two-phase drive mode based on the amount of change per unit time in the phase current of each motor phase when the test current flows through each motor phase. This configuration more appropriately sets the two-phase drive mode.

[0021] The drive device of the present disclosure can be programmed to set a target voltage ratio based on which of the first and second modes is selected, and instruct an external power supply device to apply a target voltage based on the voltage of the power storage device and the target voltage ratio to the neutral point. This configuration enables external charging through voltage conversion by the motor and inverter at a voltage ratio determined by the selected first or second mode. The voltage ratio is defined as the ratio of the neutral point voltage to the voltage of the power storage device.

[0022] In the drive device of the above aspect, in which the target voltage ratio is set based on whether the first mode or the second mode is selected, the drive device may further include a cooled device configured to circulate a cooling medium through the motor, the inverter, and the power storage device. The drive device may be programmed to set the target voltage ratio based on which of the first and second modes is selected and whether a temperature increase of the power storage device is required. This configuration allows the target voltage ratio to be set more appropriately.

[0023] In the drive device of the aforementioned aspect, in which the target voltage ratio is set based on whether the first mode or the second mode is selected, the drive device may further include a heater configured to heat the vehicle cabin using the motor and inverter as a heat source. The drive device may be programmed to set the target voltage ratio based on which of the first and second modes is selected and whether heating of the vehicle cabin is required. This configuration allows for more appropriate setting of the target voltage ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic configuration diagram of the drive unit and charging station; Figure 2 is a schematic configuration diagram of the drive unit and charging station; Figure 3 is a flowchart showing one example of an external charging control routine; Figure 4 is a diagram showing an example of phase current of each phase of a motor; Figure 5 is a diagram showing an example of the relationship between the electrical angle of the motor and the inductance value of each phase of the motor; Figure 6 is a flowchart showing an example of the first sub-process; Figure 7 is a flowchart showing one example of the second sub-process; Figure 8 is a diagram showing an example of the relationship between the voltage ratio of the multi-phase boost converter and the ripple of the phase current of each phase of the motor; Figure 9 is a flowchart showing one example of an external charging control routine according to another modification; Figure 10 is a flowchart showing one example of the third sub-process; Figure 11 is a flowchart showing one example of the third sub-process; Figure 12 This is a schematic configuration diagram of the drive device. DETAILED DESCRIPTION

[0025] Embodiments of the present disclosure are described below with reference to the accompanying drawings. Figure 1 and Figure 2 1 is a schematic configuration diagram of an embodiment of a drive device 20 mounted on a pure electric vehicle 10 and a charging stand 80 as an example of an external power supply device. Figure 1 and Figure 2As shown, the drive device 20 includes a motor 22, an inverter 24, a battery 26 as an example of a power storage device, a device-side connector 30, a switch 36, a cooler 40, a heater 50, and a drive electronic control unit (hereinafter referred to as "drive ECU") 60 as an example of a controller.

[0026] Motor 22 is configured as a three-phase AC motor and includes a rotor having permanent magnets embedded in a rotor core and a stator having a U-phase coil 22u, a V-phase coil 22v, and a W-phase coil 22w, respectively wound around a stator core. The connection of U-phase coil 22u, V-phase coil 22v, and W-phase coil 22w forms a neutral point 22n. The rotor of motor 22 is connected to drive shaft 16, which is connected to drive wheels 12 via differential gear 14.

[0027] The inverter 24 drives the motor 22 and is connected to the battery 26 via the positive and negative lines 28a and 28b of the power line 28. The inverter 24 includes six transistors T11 to T16, as an example of six switching elements, and six diodes D11 to D16. Transistors T11 to T16 are arranged in pairs, serving as the source and sink of the positive and negative lines 28a and 28b, respectively. The connection point between transistors T11 and T12, the connection point between transistors T13 and T14, and the connection point between transistors T15 and T16 are connected to the U-phase coil 22u, V-phase coil 22v, and W-phase coil 22w of the motor 22, respectively. The six diodes D11 to D16 are connected in parallel with the six transistors T11 to T16, respectively. The inverter 24 converts the direct current from the battery 26 into three-phase alternating current (AC) controlled by pulse width modulation (PWM), and supplies the three-phase AC power to the motor 22. The capacitor 29 is connected to the positive electrode side line 28 a and the negative electrode side line 28 b .

[0028] The battery 26 includes a plurality of battery cells, each configured as a lithium-ion rechargeable battery, and connected in series with one another. The battery 26 is connected to the inverter 24 via the positive electrode side line 28a and the negative electrode side line 28b as described above.

[0029] The device-side connector 30 is configured to be connected to the dock-side connector 84 of the charging dock 80. The device-side connector 30 is connected to the neutral point 22n of the motor 22 via the positive-side line 32a of the power line 32 and the switch 36, and is also connected to the negative-side line 28b via the negative-side line 32b of the power line 32. The capacitor 33 is connected to the positive-side line 32a and the negative-side line 32b. The switch 36 connects or disconnects the positive-side line 32a and the neutral point 22n of the motor 22 by turning it on or off.

[0030] When switch 36 is turned on, motor 22 and inverter 24, connected between positive and negative lines 32a and 32b of power line 32 and positive and negative lines 28a and 28b of power line 28, form a multiphase boost converter 21. Multiphase boost converter 21 includes three-phase (U, V, W) voltage converters 21u, 21v, and 21w connected in parallel with power lines 32 and 28. U-phase voltage converter 21u includes a U-phase coil 22u of motor 22 and transistors T11 and T12 of inverter 24. V-phase voltage converter 21v includes a V-phase coil 22v of motor 22 and transistors T13 and T14 of inverter 24. W-phase voltage converter 21w includes a W-phase coil 22w of motor 22 and transistors T15 and T16 of inverter 24.

[0031] The cooler 40 includes a circulation flow path 42, a heat exchanger 44, and an electric pump 46. The circulation flow path 42 is configured as a flow path for sequentially circulating cooling water to the motor 22, the inverter 24, the battery 26, and the heat exchanger 44. The electric pump 46 circulates the cooling water within the circulation flow path 42. The circulation flow path 42 can be configured to sequentially circulate cooling water to the inverter 24, the motor 22, the battery 26, and the heat exchanger 44.

[0032] Heater 50 heats the vehicle cabin using cooling water from cooler 40 (cooling water heated by motor 22 and inverter 24) as a heat source. Heater 50 includes a blower that blows heated air into the vehicle cabin by exchanging heat with heat exchanger 44.

[0033] The drive ECU 60 includes a microcomputer equipped with a CPU, ROM, RAM, flash memory, input / output ports, and a communication port. The drive ECU 60 receives input signals from various sensors. For example, the drive ECU 60 receives the rotational position θm of the motor 22's rotor from the rotational position sensor 23a, the U-phase current Iu, V-phase current Iv, and W-phase current Iw of the motor 22 from current sensors 23u, 23v, and 23w, the temperature αm of the motor 22 from the temperature sensor 23t, and the temperature αi of the inverter 24 from the temperature sensor 25t. The drive ECU 60 also receives the voltage Vb of the battery 26 from the voltage sensor 27v, the current Ib of the battery 26 from the current sensor 27i, and the temperature αb of the battery 26 from the temperature sensor 27t. The drive ECU 60 also receives the voltage VL of the capacitor 33 (power line 32) from the voltage sensor 34, and the cooling water temperature αw (i.e., the temperature of the cooling water in the circulation flow path 42) from the water temperature sensor 48. The drive ECU 60 also inputs the room temperature αc (ie, the temperature in the vehicle cabin) from the room temperature sensor 52 , and whether heating of the vehicle cabin is required and the set temperature αcset in the vehicle cabin from the heating switch 54 .

[0034] The drive ECU 60 outputs various control signals. For example, the drive ECU 60 outputs control signals to the transistors T11 and T16 of the inverter 24, the switch 36, the electric pump 46, and the heater 50. The drive ECU 60 calculates the electrical angle θe and the rotational speed Nm of the motor 22 based on the rotational position θm of the rotor of the motor 22. The drive ECU 60 calculates the state of charge (SOC) of the battery 26 based on the accumulated value of the current Ib of the battery 26. The drive ECU 60 sets the input limit Win, which represents the allowable input power of the battery 26, based on the state of charge (SOC) of the battery 26 and the temperature αb of the battery 26. The drive ECU 60 is capable of communicating with the electronic control unit 88 (hereinafter referred to as the "charging station ECU") of the charging station 80 (hereinafter referred to as the "charging station ECU") at home or at a charging station.

[0035] The charging stand 80 is located at home, at a charging station, and the like. The charging stand 80 includes a power supply device 82, a stand-side connector 84, and a charging stand ECU 88. The power supply device 82 is connected to the stand-side connector 84 via the positive side line 86a and the negative side line 86b of the power line 86. The power supply device 82 is configured to convert AC power from the power system into DC power and adjust the output voltage and output power. The stand-side connector 84 is configured to be connected to the device-side connector 30 of the drive device 20. When the stand-side connector 84 is connected to the device-side connector 30, the positive side line 86a is connected to the positive side line 32a, and the negative side line 86b is connected to the negative side line 32b, respectively.

[0036] The charging station ECU 88 includes a microcomputer equipped with a CPU, ROM, RAM, flash memory, input / output ports, and a communication port. The charging station ECU 88 receives the output voltage Vs of the power supply device 82 from a voltage sensor 83v and the output current Is of the power supply device 82 from a current sensor 83i. The charging station ECU 88 outputs a control signal to the power supply device 82. Based on the output voltage Vs and the output current Is, the charging station ECU 88 calculates the output power Ps. The charging station ECU 88 is capable of communicating with the drive ECU 60 of the drive device 20.

[0037] The following describes the operation of drive device 20, particularly during external charging. External charging involves charging battery 26 using power from power supply device 82 of charging station 80. During external charging, neutral power supplied by power supply device 82 to neutral point 22n of motor 22 undergoes voltage conversion by multi-phase boost converter 21 (motor 22 and inverter 24) and is then supplied to battery 26. Figure 31 is a flowchart illustrating an example of an external charging control routine executed by the drive ECU 60. This routine is executed when the device-side connector 30 of the drive device 20 is connected to the dock-side connector 84 of the charging dock 80 and a charging start condition is satisfied. The charging start condition is, for example, an OR condition such as a user instruction to start charging the battery 26 or a user-set charging start time for the battery 26 having arrived.

[0038] exist Figure 3 In the external charging control routine shown, drive ECU 60 first turns on switch 36 (step S100). This connects neutral point 22n of motor 22 to positive-side line 32a. Thus, as described above, multiphase boost converter 21 (three-phase voltage converters 21u, 21v, 21w) is composed of motor 22 and inverter 24, which are connected between power line 32 and power line 28.

[0039] Then, the drive ECU 60 sets the two-phase drive for efficiency and heat generation (step S110). In the present embodiment, the drive ECU 60 performs three-phase interleaved drive or two-phase interleaved drive during external charging. In the three-phase interleaved drive, switching control of the transistors T11 to T16 of the inverter 24 is performed so that the U-phase current Iu, V-phase current Iv, and W-phase current Iw of the motor 22 are offset from each other by 120 degrees. For example, in the three-phase interleaved drive, the phases of the respective phase carriers (e.g., triangular wave, sawtooth wave, inverse sawtooth wave, etc.) in the duty cycle control of the U-phase transistors T11 and T12, the V-phase transistors T13 and T14, and the W-phase transistors T15 and T16 of the inverter 24 can be offset from each other by 120 degrees, so that the phases of the U-phase current Iu, V-phase current Iv, and W-phase current Iw of the motor 22 are offset from each other by 120 degrees. In the two-phase interleaved drive, switching control of the transistors T11 to T16 of the inverter 24 is performed so that the phases of the phase currents of the two phases of the motor 22 (for example, the V-phase current Iv and the W-phase current Iw) are offset by 180 degrees from each other. For example, in the two-phase interleaved drive, the phases of the two-phase currents of the motor 22 can be offset by 180 degrees from each other by the phases of the carrier waves of each phase in the duty cycle control of the two-phase transistors of the inverter 24. The three-phase interleaved drive corresponds to the interleaved drive in the first mode of the present disclosure, and the two-phase interleaved drive corresponds to the interleaved drive in the second mode of the present disclosure. The two driving phases are the two phases to be driven by the two-phase interleaved drive in the multi-phase boost converter 21 (three-phase voltage converters 21u, 21v, 21w).

[0040] Figure 4 is a diagram showing one example of the phase currents Iu, Iv, and Iw of the motor 22 . Figure 4 (A) shows an example of a case where three-phase interleaved driving is performed. Figure 4(B) shows an example of a case where two-phase interleaved driving is performed, in which two phases are driven as two phases having the largest difference (disparity) in inductance values ​​among the three phases of the motor 22 . Figure 4 (C) shows an example of a case where two-phase interleaved driving is performed, in which two phases are driven as two phases having the smallest difference in inductance value among the three phases of the motor 22 . Figure 4 The figure shows a case where the difference between the inductance value Lv of the V phase and the inductance value Lw of the W phase is the smallest, and the difference between the inductance value Lu of the U phase and the inductance value Lv of the V phase is the largest. The ripple of the phase current of each phase of the motor 22 depends on the inductance value. Figure 4 (A) Figure 4 (B) and Figure 4 In the example shown in (C), the ripple (amplitude) Iru of the U-phase current Iu is slightly larger than the ripple Irv of the V-phase current Iv and the ripple Irw of the W-phase current Iw, and the ripple Irw of the W-phase current Irw is slightly larger than the ripple Irv of the V-phase current Iv. Therefore, Figure 4 (A) The ripple Ira of the sum of the phase currents Iu, Iv, and Iw is Figure 4 (B) The ripple Irb of the sum of the phase currents Iu and Iv is shown as follows: Figure 4 The ripple Irc of the sum of the phase currents Iv and Iw shown in (C) is rippled Ira, Irb, and Irc in descending order. The present inventors have confirmed through experiments, analysis, and machine learning that the smaller the ripple of the total current, the more the eddy current loss in the motor 22 is suppressed, and the less heat is generated in the motor 22. Based on these considerations, in step S110, the drive ECU 60 sets the two driving phases for efficiency to the two phases with the smallest difference in inductance value among the three phases of the motor 22, and sets the two driving phases for heat generation to the two phases with the largest difference in inductance value among the three phases of the motor 22.

[0041] The process of step S110 is performed, for example, by applying the electrical angle θe to a two-phase driving map to derive the two-phase driving map. The two-phase driving map is predetermined through experiments, analysis, or machine learning as the relationship between the electrical angle θe of the motor 22 and the two-phase driving map for efficiency and heat generation. Figure 5 This is a diagram showing an example of the relationship between the electrical angle θe of the motor 22 and the inductance values ​​Lu, Lv, and Lw of each phase of the motor 22. As shown in the figure, the inductance values ​​Lu, Lv, and Lw of each phase depend on the electrical angle θe. By considering the relationship between the electrical angle θe and the inductance values ​​Lu, Lv, and Lw, a mapping for driving two phases is defined. Figure 5In the example shown, when the electrical angle θe of the motor 22 is 59 degrees, the difference between the inductance values ​​Lv and Lw of the V-phase and the W-phase is smallest, and the difference between the inductance values ​​Lu and Lv of the U-phase and the V-phase is largest. In this case, the drive ECU 60 sets the V-phase and W-phase as the two drive phases for efficiency, and sets the U-phase and V-phase as the two drive phases for heat generation.

[0042] The drive ECU 60 then sets a target power Ps* (step S120). Target power Ps* is the power supplied by the power supply device 82 to the neutral point 22n of the motor 22, that is, the target value of the neutral-point power. For example, the process of step S120 is performed by setting target power Ps* within the input limit Win of the battery 26.

[0043] The drive ECU 60 then determines whether heating of the battery 26 is required (step S130) and whether heating of the vehicle cabin is required (step S132). The process of determining whether heating of the battery 26 is required is performed by determining whether the temperature αb of the battery 26 is equal to or less than a threshold value Tbth (which is a relatively low value). For example, the threshold value Tbth is approximately -10°C to 10°C. The process of determining whether heating of the vehicle cabin is required is performed by determining whether a heating condition is satisfied. The heating condition is used as the condition that the heating switch 54 is turned on and the room temperature αc is lower than the set temperature αc.

[0044] When the drive ECU 60 determines in step S130 that the temperature increase of the battery 26 is not required and in step S132 that the heating of the vehicle cabin is not required, the drive ECU 60 executes Figure 6 On the other hand, when the drive ECU 60 determines in step S130 that the temperature increase of the battery 26 is required or in step S132 that the heating of the vehicle cabin is required, the drive ECU 60 executes Figure 7 The second sub-process (step S150) is shown. The first and second sub-processes are processes for the charging stand ECU 88 to perform three-phase interleaved driving or two-phase interleaved driving and transmit the target power Ps* and target voltage Vs* to the charging stand 80. The target voltage Vs* is the voltage applied by the power supply device 82 to the neutral point 22n of the motor 22. The details of the first and second sub-processes are described below.

[0045] The drive ECU 60 then determines whether a charge stop condition is satisfied (step S160). The charge stop condition is, for example, an OR condition such as the state of charge (SOC) of the battery 26 reaching or exceeding a threshold value (Sth), or a user instructing to stop charging the battery 26. If it is determined in step S160 that the charge stop condition is not satisfied, the drive ECU 60 returns to step S120.

[0046] If the charging stop condition is determined to be satisfied in step S160, the drive ECU 60 executes a stop process (step S170) and then terminates the routine. During the stop process, the drive ECU 60 stops the inverter 24 and sends a power supply stop command to the charging stand ECU 88. Upon receiving the power supply stop command, the charging stand ECU 88 stops the power supply device 82. This terminates external charging.

[0047] Described below Figure 3 The process of step S140 of the external charging control routine shown is Figure 6 As mentioned above, when the drive ECU 60 determines in step S130 that the temperature increase of the battery 26 is not required and in step S132 that the heating of the vehicle cabin is not required, the first sub-process is executed.

[0048] In the first sub-process, the drive ECU 60 first determines whether the target power Ps* is equal to or less than the threshold value Psref (step S200). The inventors have confirmed the following through experiments, analysis, and machine learning. As mentioned above, when two-phase interleaved drive is performed, the eddy current loss of the motor 22 is suppressed, and the heating (temperature increase) of the motor 22 caused by the eddy current loss is also suppressed compared to when three-phase interleaved drive is performed. However, because the current is concentrated in the two driving phases when two-phase interleaved drive is performed, the heating of the inverter 24 and the heating of the motor 22 caused by copper loss in the motor 22 are greater when two-phase interleaved drive is performed than when three-phase interleaved drive is performed. The heating of the motor 22 is more affected by eddy current loss than by copper loss. When the neutral point power is relatively low, the heating (heat loss) of the entire drive unit, including the motor 22 and the inverter 24, is more affected by the heating of the motor 22 (particularly the heating caused by eddy current loss) than by the heating of the inverter 24. Therefore, when the neutral point power is relatively low, when three-phase interleaved drive is executed, the entire drive unit generates more heat and has lower external charging efficiency than when two-phase interleaved drive is executed. On the other hand, when the neutral point power is relatively high, the heat generation of the entire drive unit is more affected by the heat generation of inverter 24 than by the heat generation of motor 22. Therefore, when the neutral point power is relatively high, when two-phase interleaved drive is executed, the entire drive unit generates more heat and has lower external charging efficiency than when three-phase interleaved drive is executed. Threshold value Psref is determined based on the specifications of motor 22 and inverter 24 through experiments, analysis, or machine learning, and serves as the boundary value between the region where the entire drive unit generates more heat when three-phase interleaved drive is executed and the region where the entire drive unit generates more heat when two-phase interleaved drive is executed. Threshold value Psref is, for example, several tens of kW.

[0049] If it is determined in step S200 that target power Ps* is equal to or less than threshold value Psref, drive ECU 60 sets the number of drive phases Np to 2 (step S210) and sets the target voltage ratio Rv* of multi-phase boost converter 21 to a predetermined value Rv1 (step S212). Number of drive phases Np is the number of drive phases (three or two) driven by interleaved drive of multi-phase boost converter 21 (three-phase voltage conversion units 21u, 21v, 21w). Target voltage ratio Rv* of multi-phase boost converter 21 is defined as the voltage ratio between the target voltage of power line 32 (target voltage of power supply device 82) and the voltage of power line 28 (voltage of battery 26). On the other hand, if it is determined in step S200 that target power Ps* is greater than threshold value Psref, drive ECU 60 sets number of drive phases Np to 3 (step S220) and sets target voltage ratio Rv* of multi-phase boost converter 21 to a predetermined value Rv2 (step S222). As can be seen from the above, when neither the temperature increase of the battery 26 nor the heating of the vehicle cabin is required, the drive ECU 60 performs the three-phase interleaved drive or the two-phase interleaved drive, whichever generates less heat (heat loss) in the entire drive unit. The predetermined values ​​Rv1 and Rv2 are as follows.

[0050] The drive ECU 60 then calculates the target voltage Vs* (step S230) and transmits the target power Ps* and target voltage Vs* to the charging stand ECU 88 of the charging stand 80 (step S240). The target voltage Vs* is calculated as the product of the voltage Vb of the battery 26 and the target voltage ratio Rv* of the multi-phase boost converter 21. Upon receiving the target power Ps* and target voltage Vs*, the charging stand ECU 88 controls the power supply device 82 so that the output voltage Vs equals the target voltage Vs* and the output power Ps equals the target power Ps*.

[0051] Then, the drive ECU 60 determines whether the number of drive phases Np is 3 or 2 (step S250). When it is determined that the number of drive phases Np is 3, the drive ECU 60 performs three-phase interleaved drive (step S260) and terminates the first sub-processing. On the other hand, when it is determined that the number of drive phases Np is 2, the drive ECU 60 uses the two drive phases for efficiency set in step S110 to perform two-phase interleaved drive (step S270) and terminates the first sub-processing. When neither the battery 26 is required to be heated nor the heating inside the vehicle cabin is required, the drive ECU 60 performs the one with the smaller heat generation (heat loss) of the entire drive unit between the three-phase interleaved drive and the two-phase interleaved drive. Therefore, efficient external charging can be achieved. In addition, when performing two-phase interleaved drive, the drive ECU 60 uses the two drive phases for efficiency instead of the two drive phases for heat generation. As a result, this suppresses the eddy current loss of the motor 22 and further suppresses the heat generation of the entire drive unit. The duty ratios of the transistors T11 to T16 in the three-phase interleaved drive or the two-phase interleaved drive are set based on the target voltage ratio Rv* of the multi-phase boost converter 21 .

[0052] Described below Figure 3 The process of step S150 of the external charging control routine shown is Figure 7 As mentioned above, when the drive ECU 60 determines in step S130 that the temperature increase of the battery 26 is required or in step S132 that the heating of the vehicle cabin is required, the second sub-process is executed.

[0053] In the second sub-process, the drive ECU 60 first determines whether the target power Ps* is less than the threshold value Psref (step S300). When it is determined that the target power Ps* is less than the threshold value Psref, the drive ECU 60 sets the number of drive phases Np to 3 (step S310) and sets the target voltage ratio Rv* of the multi-phase boost converter 21 to the predetermined value Rv3 (step S312). On the other hand, when it is determined that the target power Ps* is equal to or greater than the threshold value Psref, the drive ECU 60 sets the number of drive phases Np to 2 (step S320) and sets the target voltage ratio Rv* of the multi-phase boost converter 21 to the predetermined value Rv4 (step S322). As can be seen from the above, when at least one of the heating of the battery 26 and the heating of the vehicle cabin is required, the drive ECU 60 executes the three-phase interleaved drive and the two-phase interleaved drive, whichever has the larger heat generation (heat loss) of the entire drive unit. The predetermined values ​​Rv3 and Rv4 are described below.

[0054] Then, the driving ECU 60 calculates the target voltage Vs* (step S330), transmits the target power Ps* and the target voltage Vs* to the charging stand ECU 88 (step S340), and determines whether the number of driving phases Np is 3 or 2 (step S350), similar to Figure 6Steps S230 to S250 of the first sub-process are shown. When it is determined that the number of drive phases Np is 3, the drive ECU 60 performs three-phase interleaved drive (step S360) and terminates the second sub-process. On the other hand, when it is determined that the number of drive phases Np is 2, the drive ECU 60 performs two-phase interleaved drive using the two drive phases for heat generation set in step S110 (step S370) and terminates the second sub-process. When at least one of heating the battery 26 or heating the vehicle cabin is required, the drive ECU 60 performs the three-phase interleaved drive or the two-phase interleaved drive, whichever results in a greater amount of heat generated (heat loss) by the entire drive unit. As a result, more heat from the motor 22 and inverter 24 is supplied to the battery 26 via the cooling water in the cooler 40, and the air blown into the vehicle cabin is further heated by heat exchange with the heat exchanger 44 of the cooler 40. As a result, the heating of the battery 26 is accelerated and / or the vehicle cabin is more fully heated. In addition, when performing two-phase interleaved driving, the drive ECU 60 uses the two driving phases for heat generation rather than the two driving phases for efficiency, which further increases the heat generation of the entire drive unit.

[0055] The predetermined values ​​Rv1 to Rv4 are described in this section. Figure 8 : This is a diagram showing an example of the relationship between the voltage ratio Rv of the multi-phase boost converter 21 and the ripples Iru, Irv, and Irw of the phase currents Iu, Iv, and Iw of the motor 22. The voltage ratio Rv of the multi-phase boost converter 21 is defined as the voltage ratio between the voltage of the power line 32 (the output voltage of the power supply device 82) and the voltage of the power line 28 (the voltage of the battery 26). Figure 8 (A) shows an example of the relationship when three-phase interleaved driving is performed. Figure 8 (B) shows an example of the relationship when two-phase interleaved driving is performed. Figure 4 Similar to the following, Figure 8 (A) shows a case where the difference between the inductance value Lv of the V phase and the inductance value Lw of the W phase is the smallest, and the difference between the inductance value Lu of the U phase and the inductance value Lv of the V phase is the largest. Figure 8 (B) also shows an example of the relationship when two-phase interleaved driving is performed using two drive phases for efficiency. When two-phase interleaved driving is performed using two drive phases for heat generation, it can be considered in the same way as when two-phase interleaved driving is performed using two drive phases for efficiency.

[0056] like Figure 8As shown in (A), when the drive ECU 60 performs three-phase interleaved driving, when the voltage ratio Rv of the multi-phase boost converter 21 is 0.5, the ripple Iru of the U-phase phase current Iu of the motor 22, the ripple Irv of the V-phase phase current Iv, and the ripple Irw of the W-phase phase current Irw are all very large, and become smaller as the voltage ratio Rv of the multi-phase boost converter 21 moves away from 0.5. Figure 8 As shown in Figure 2 (B), when the voltage ratio Rv of multi-phase boost converter 21 is 0.5, the ripple Irv of V-phase current Iv and the ripple Irw of W-phase current Iw are both very small. However, when the voltage ratio Rv of multi-phase boost converter 21 is approximately 0.3 or 0.7, the ripple Irv of V-phase current Iv and the ripple Irw of W-phase current Iw are also very large. The inventors have confirmed through experiments, analysis, and machine learning that the greater the ripple of the phase current of each phase of motor 22, the greater the heat generation (heat loss) of the entire drive unit.

[0057] Based on these considerations, the predetermined value Rv1 is set to, for example, 0.5, and the predetermined value Rv2 is set to, for example, 0.33 or 0.67. As can be seen from the above, in three-phase interleaved drive or two-phase interleaved drive, when neither heating of the battery 26 nor heating of the vehicle cabin is required, the heat generation (heat loss) of the entire drive unit is suppressed. Consequently, efficient external charging can be achieved.

[0058] The predetermined value Rv3 is used, for example, at 0.5, and the predetermined value Rv4 is used, for example, at 0.33 or 0.67. As can be seen from the above, when at least one of heating the battery 26 or heating the vehicle cabin is required, the heat generation (heat loss) of the entire drive unit increases in three-phase interleaved drive or two-phase interleaved drive. As a result, the heating of the battery 26 is accelerated and / or the vehicle cabin is more fully heated.

[0059] In the drive device 20 of the above-described embodiment, the drive ECU 60 performs three-phase interleaved drive (driving the inverter 24 in the first mode) or two-phase interleaved drive (driving the inverter 24 in the second mode) during external charging, wherein the power supplied by the power supply device 82 to the neutral point 22n of the motor 22 of the charging stand 80 is subjected to voltage conversion by the multi-phase boost converter 21 (the motor 22 and the inverter 24) to be supplied to the battery 26. External charging is more appropriately performed.

[0060] Specifically, when neither heating the battery 26 nor heating the vehicle cabin is required, the drive ECU 60 performs two-phase interleaved drive when the target power Ps* is equal to or less than the threshold value Psref, and when the target power Ps* is greater than the threshold value Psref, the drive ECU 60 performs three-phase interleaved drive. In this configuration, the three-phase interleaved drive and the two-phase interleaved drive, whichever generates less heat (heat loss) for the entire drive unit, are executed. Therefore, efficient external charging can be achieved. In addition, when neither heating the battery 26 nor heating the vehicle cabin is required, when performing two-phase interleaved drive, the drive ECU 60 uses the two drive phases for efficiency rather than the two drive phases for heat generation. This further suppresses the heat generation of the entire drive unit.

[0061] In the case where at least one of the heating of the battery 26 and the heating of the cabin is required, the drive ECU 60 performs three-phase interleaved drive when the target power Ps* is less than the threshold value Psref, and performs two-phase interleaved drive when the target power Ps* is equal to or greater than the threshold value Psref. In this configuration, the three-phase interleaved drive and the two-phase interleaved drive, whichever has a larger heat generation (heat loss) of the entire drive unit, are performed. Therefore, the heating of the battery 26 is accelerated and / or the cabin is heated more fully. In addition, in the case where at least one of the heating of the battery 26 or the heating of the cabin is required, when the two-phase interleaved drive is performed, the drive ECU 60 uses the two phases of drive for heat generation instead of the two phases of drive for efficiency. This further increases the heat generation of the entire drive unit.

[0062] In drive device 20 of this embodiment, during external charging, drive ECU 60 sets target voltage ratio Rv* for multi-phase boost converter 21 based on whether battery 26 temperature increase is required, whether cabin heating is required, and number Np of drive phases in interleaved drive. Drive ECU 60 then transmits target voltage Vs* based on battery 26 voltage Vb and target voltage ratio Rv* to charging stand ECU 88. Charging stand ECU 88 controls power supply device 82 so that output voltage Vs equals target voltage Vs*. This enables external charging to be performed more appropriately.

[0063] Specifically, when neither battery 26 heating nor vehicle cabin heating is required, drive ECU 60 sets the target voltage ratio Rv* of multi-phase boost converter 21 to minimize the ripple in the phase current of each phase of motor 22 during three-phase interleaved drive and two-phase interleaved drive. This reduces heat generation (heat loss) across the entire drive unit, enabling efficient external charging.

[0064] When at least one of increasing the temperature of battery 26 or heating the vehicle cabin is required, drive ECU 60 sets target voltage ratio Rv* of multi-phase boost converter 21 so that the ripple of the phase current of each phase of motor 22 during three-phase interleaved drive and two-phase interleaved drive is larger. This configuration increases the heat generation of the entire drive unit. Consequently, the temperature increase of battery 26 is accelerated and / or the vehicle cabin is more fully heated.

[0065] In the above embodiment, the driving ECU 60 is based on Figure 3 In the external charging control routine shown, the two-phase drive for efficiency and heat generation is set based on the electrical angle θe of the motor 22. However, the drive ECU 60 can set the two-phase drive for efficiency and heat generation as follows. The drive ECU 60 turns on transistors T12, T14, and T16 of the inverter 24 and sends a test voltage command to the charging station ECU 88. The charging station ECU 88 controls the power supply device 82 to apply a test voltage (e.g., a constant voltage for a predetermined time) to the neutral point 22n of the motor 22. This causes phase current to flow in each phase of the motor 22. The drive ECU 60 detects the phase current change rates ΔIu, ΔIv, and ΔIw—that is, the amount of change in the phase currents Iu, Iv, and Iw of each phase of the motor 22 per unit time—and sets the two-phase drive for efficiency and heat generation based on the detected phase current change rates ΔIu, ΔIv, and ΔIw. The phase current change rates ΔIu, ΔIv, and ΔIw depend on the inductance values ​​Lu, Lv, and Lw of each phase. Therefore, the drive ECU 60 sets the two phases driven for efficiency to the two phases with the smallest difference in the rate of change of the phase current of the motor 22 phases, and sets the two phases driven for heat generation to the two phases with the largest difference in the rate of change of the phase current of the motor 22 phases. In this case, the drive device 20 and the charging station 80 simultaneously flow phase currents to the three phases of the motor 22 and detect the phase current change rate ΔIu, ΔIv, and ΔIw of each phase. Alternatively, the drive device 20 and the charging station 80 may sequentially flow phase currents to each phase of the motor 22 and detect the phase current change rate ΔIu, ΔIv, and ΔIw of each phase.

[0066] In the above embodiment, the driving ECU 60 is based on Figure 3 In the external charging control routine shown, it is determined whether the temperature rise of the battery 26 and the heating of the vehicle cabin are required. Figure 6 The first sub-process shown or Figure 7 However, the drive ECU 60 may perform the first sub-process or the second sub-process based on only one of whether the temperature rise of the battery 26 is required and whether heating of the vehicle cabin is required.

[0067] In the above embodiment, the drive ECU 60 is based on whether the temperature rise of the battery 26 is required, whether heating of the vehicle cabin is required, and whether the vehicle cabin heating is required. Figure 3The external charging control routine shown ( Figure 6 The first subprocess shown and Figure 7 The drive ECU 60 sets the number of drive phases Np in the interleaved drive based on the target power Ps* in the sub-routine (shown in FIG. 1 ). However, the drive ECU 60 may also set the number of drive phases Np in the interleaved drive based solely on the target power Ps*. In this case, when the target power Ps* is equal to or less than the threshold value Psref, the drive ECU 60 may set the number of drive phases Np to 2, and when the target power Ps* is greater than the threshold value Psref, the drive ECU 60 may set the number of drive phases Np to 3.

[0068] In the above embodiment, the driving ECU 60 is based on Figure 3 The external charging control routine shown ( Figure 6 The first subprocess shown and Figure 7 The target voltage ratio Rv* is set based on whether the battery 26 is required to be heated in the sub-process (shown in FIG. 1 ), whether the vehicle cabin is required to be heated, and the number of drive phases Np in the interleaved drive. However, the drive ECU 60 may set the target voltage ratio Rv* based solely on the number of drive phases Np in the interleaved drive. In this case, for example, the drive ECU 60 may set the target voltage ratio Rv* to a predetermined value Rv1 or Rv2. The target voltage ratio Rv* may be a predetermined constant value.

[0069] In the above embodiment, the driving ECU 60 is based on Figure 3 The external charging control routine shown ( Figure 6 The first subprocess shown and Figure 7 In the two-phase interleaved drive, the two driving phases for efficiency or heat generation are used depending on whether the temperature rise of the battery 26 and the heating of the vehicle cabin are required in the sub-process shown in FIG. However, the drive ECU 60 may always use the two driving phases for efficiency or the predetermined two driving phases.

[0070] In the above embodiment, the driving ECU 60 executes Figure 3 However, the drive ECU 60 may execute Figure 9 The external charging control routine is shown. Figure 9 The external charge control routine shown is similar to Figure 3 The external charging control routine shown differs in that steps S400 to S430 are added.

[0071] exist Figure 9In the external charging control routine shown, the drive ECU 60 calculates the thermal margins Δαm and Δαi for the motor 22 and inverter 24 after setting the target power Ps* in step S120 (step S400). The thermal margin Δαm for the motor 22 is calculated as a value obtained by subtracting the motor 22 temperature αm from the predetermined temperature αmref. The thermal margin Δαi for the inverter 24 is calculated as a value obtained by subtracting the inverter 24 temperature αi from the predetermined temperature αiref. The predetermined temperature αmref is determined to be slightly lower than the overheating temperature of the motor 22, for example, using a range of 80°C to 120°C. The predetermined temperature αiref is determined to be slightly lower than the overheating temperature of the inverter 24, for example, using a range of 80°C to 120°C. The smaller the values ​​of the thermal margins Δαm and Δαi for the motor 22 and inverter 24, the hotter the motor 22 and inverter 24 are.

[0072] Then, the drive ECU 60 determines whether the thermal margin Δαm of the motor 22 is equal to or greater than 0 (step S410) and whether the thermal margin Δαi of the inverter 24 is equal to or greater than 0 (step S420). When the drive ECU 60 determines that the thermal margin Δαm of the motor 22 is equal to or greater than 0 and the thermal margin Δαi of the inverter 24 is equal to or greater than 0, it proceeds to step S130. On the other hand, when it is determined that the thermal margin Δαm of the motor 22 is less than 0 or the thermal margin Δαi of the inverter 24 is less than 0, the drive ECU 60 performs Figure 10 The third sub-process shown (step S430) and enters step S160.

[0073] Described below Figure 10 The third sub-process is shown. Figure 10 The third sub-process shown is the same as Figure 6 The first sub-process shown is different in that steps S500 to S520 are added.

[0074] exist Figure 10 In the third sub-process shown, the drive ECU 60 first determines whether the thermal margin Δαm of the motor 22 is equal to or less than the thermal margin Δαi of the inverter 24 (step S500). If it is determined that the thermal margin Δαm of the motor 22 is equal to or less than the thermal margin Δαi of the inverter 24, the drive ECU 60 resets the target power Ps* (step S510) and proceeds to step S200. The process of step S510 is performed by setting the new target power Ps* to the value obtained by subtracting the correction value ΔPs1 from the target power Ps* set in step S120. The correction value ΔPs1 can be a constant value or a value that increases as the thermal margin Δαm of the motor 22 decreases (increases in absolute value within a negative range).

[0075] The processing in step S510 results in a lower neutral-point power. This suppresses temperature increases in the motor 22 and inverter 24. Furthermore, when the target power Ps* is equal to or less than the threshold value Psref, the drive ECU 60 performs two-phase interleaved drive, while when the target power Ps* is greater than the threshold value Psref, the drive ECU 60 performs three-phase interleaved drive, as if neither heating the battery 26 nor heating the vehicle cabin is required. This suppresses heating in the motor 22 due to eddy current losses when the target power Ps* is equal to or less than the threshold value Psref, and suppresses heating in the motor 22 due to copper losses when the target power Ps* is greater than the threshold value Psref. Furthermore, the drive ECU 60 uses two-phase drive for efficiency and sets the target voltage ratio Rv* of the multi-phase boost converter 21 to a predetermined value Rv1, as if neither heating the battery 26 nor heating the vehicle cabin is required. This further suppresses the amount of heat generated (heat loss) in the entire drive unit.

[0076] If it is determined in step S500 that the thermal margin Δαm of the motor 22 is greater than the thermal margin Δαi of the inverter 24, the drive ECU 60 resets the target power Ps* (step S520) and proceeds to step S220. The process of step S520 is performed by setting the new target power Ps* to a value obtained by subtracting the correction value ΔPs2 from the target power Ps* set in step S120. The correction value ΔPs2 can be a constant value (e.g., the same value as the correction value ΔPs1) or a value that increases as the thermal margin Δαi of the inverter 24 decreases (increases in absolute value within a negative range).

[0077] This process results in a smaller neutral point power. This suppresses the temperature rise of the motor 22 and the inverter 24. When the heat generation of the inverter 24 is more serious than that of the motor 22, the drive device 20 performs three-phase interleaved drive. This can suppress the temperature of the inverter 24 from rising further compared to when the two-phase interleaved drive is performed. In addition, the drive ECU 60 uses the two-phase drive for efficiency and sets the target voltage ratio Rv* of the multi-phase boost converter 21 to the predetermined value Rv2, just as in the case where neither the temperature rise of the battery 26 nor the heating of the vehicle cabin is required. This further suppresses the heat generation (heat loss) of the entire drive unit.

[0078] exist Figure 9 In the external charging control routine shown, when the drive ECU 60 determines that the thermal margin Δαm of the motor 22 is less than 0, or when the drive ECU 60 determines that the thermal margin Δαi of the inverter 24 is less than 0, the drive ECU 60 executes Figure 10However, the drive ECU 60 may execute the processing of step S510 or subsequent steps of the third sub-process only when the drive ECU 60 determines that the thermal margin Δαm of the motor 22 is less than 0. In addition, the drive ECU 60 may execute the processing of step S520 or subsequent steps of the third sub-process only when the drive ECU 60 determines that the thermal margin Δαi of the inverter 24 is less than 0.

[0079] exist Figure 10 In the sub-process shown, the drive ECU 60 resets the target power Ps* when the drive ECU 60 determines that the thermal margin Δαm of the motor 22 is equal to or less than the thermal margin Δαi of the inverter 24, and when the drive ECU 60 determines that the thermal margin Δαm of the motor 22 is greater than the thermal margin Δαi of the inverter 24. However, the drive ECU 60 may reset the target power Ps* only when the drive ECU 60 determines that the thermal margin Δαm of the motor 22 is equal to or less than the thermal margin Δαi of the inverter 24. The drive ECU 60 may also reset the target power Ps* only when the drive ECU 60 determines that the thermal margin Δαm of the motor 22 is greater than the thermal margin Δαi of the inverter 24. Further, when the drive ECU 60 determines that the thermal margin Δαm of the motor 22 is equal to or less than the thermal margin Δαi of the inverter 24, or when the drive ECU 60 determines that the thermal margin Δαm of the motor 22 is greater than the thermal margin Δαi of the inverter 24, in either case, the drive ECU 60 may not reset the target power Ps*.

[0080] Figure 10 The third sub-process shown can be represented by Figure 11 The third sub-process shown is used instead. Figure 11 The third subprocess shown is the same as Figure 10 The third sub-process shown is different in that, after the processing of step S520, the processing proceeds to step S200 instead of step S220.

[0081] In the above embodiment, the drive ECU 60 Figure 3 and Figure 9 The target power Ps* is set in step S120 of the external charging control routine shown in FIG. Figure 6 Step S200 of the first sub-process shown, Figure 7 Steps S300 and S301 of the second sub-process shown in FIG. Figure 11 The target power Ps* is used in step S200 of the third sub-process shown in FIG. Figure 10 and Figure 11 and Figure 11The target power Ps* is reset in steps S510 and S520 shown. However, the target power Ps* can also be replaced by the target current Is*. The target current Is* is the current supplied by the power supply device 82 to the neutral point 22n of the motor 22. When using the target current Is*, it can be considered in the same way as when using the target power Ps*. In steps S200 and 300, the neutral point power or neutral point current supplied by the power supply device 82 to the neutral point 22n of the motor 22 can be used instead of the target power Ps* or the target current Is*. The neutral point power or neutral point current can be used as the output power Ps or output current Is of the power supply device 82, respectively.

[0082] In the above embodiment, the drive ECU 60 performs three-phase interleaved drive or two-phase interleaved drive during external charging. However, in addition to or instead of this, the drive ECU 60 may perform three-phase interleaved drive or two-phase interleaved drive during external power supply. External power supply is the use of the power of the battery 26 to supply power to the outside of the drive device 20 (pure electric vehicle 10). In external power supply, the power from the battery 26 is supplied to the outside of the drive device 20 through voltage conversion by the multi-phase boost converter 21 (motor 22 and inverter 24). The determination of whether to perform three-phase interleaved drive and two-phase interleaved drive can be considered in the same manner as the determination during external charging.

[0083] In the above embodiment, the drive ECU 60 performs three-phase interleaved driving or two-phase interleaved driving during external charging. However, during external charging, the drive ECU 60 may control the inverter 24 in a first mode in which all three phases of the inverter 24 are driven, or in a second mode in which two of the three phases of the inverter 24 are driven. For example, the drive ECU 60 may switch transistors T11-T16 of the inverter 24 so that the phase currents of the motor 22 are in phase in either the first mode or the second mode. The same considerations apply during external power supply as during external charging.

[0084] In the above embodiment, the pure electric vehicle 10 includes the drive device 20. However, as Figure 12As shown, the pure electric vehicle 10 may include a drive device 20B. The drive device 20B differs from the drive device 20 in that it also includes a power line 38. In the drive device 20B, the battery 26 is composed of a first battery 26a and a second battery 26b connected in series with each other. The first battery 26a and the second battery 26b are both composed of a plurality of battery cells connected in series with each other. The power line 38 is connected to the neutral point 22n of the motor 22 and the connection point 26p between the first battery 26a and the second battery 26b. In this drive device 20B, when external charging is not performed, the drive ECU 60 drives the inverter 24 to increase the temperature of the first battery 26a and the second battery 26b.

[0085] In the above embodiment, each battery cell of the battery 26 of the driving device 20 is configured as a lithium-ion rechargeable battery. However, each battery cell may be configured as a nickel-metal hydride rechargeable battery.

[0086] In the above-described embodiment, the power storage device is the battery 26. However, the power storage device may also be a capacitor.

[0087] In the above embodiment, the heater 50 of the drive device 20 uses the cooling water of the cooler 40 (cooling water heated by the motor 22 and the inverter 24) as a heat source to heat the vehicle cabin. However, the heater 50 is not limited to this configuration as long as the heater 50 uses the motor 22 and the inverter 24 as a heat source to heat the vehicle cabin.

[0088] In the above embodiment, the drive device 20 is mounted on the pure electric vehicle 10. However, the drive device 20 may be mounted on a hybrid electric vehicle or a fuel cell electric vehicle, or on a mobile object other than a vehicle, or on non-mobile construction equipment.

[0089] The following describes the correspondence between the main elements of the above-described embodiment and the main elements of the present disclosure described in the Summary of the Invention. In this embodiment, the motor 22 corresponds to the "motor," the battery 26 corresponds to the "power storage device," the inverter 24 corresponds to the "inverter," and the drive ECU 60 corresponds to the "controller."

[0090] The correspondence between the main elements of the embodiment and the main elements of the present disclosure related to the problem described in the Summary of the Invention should not be regarded as limiting the elements of the present disclosure related to the problem described in the Summary of the Invention, because the embodiment is merely exemplary and is used to specifically describe various aspects of the present disclosure related to the problem described in the Summary of the Invention. In other words, the present disclosure related to the problem described in the Summary of the Invention should be interpreted based on the description in the Summary of the Invention, and the embodiment is merely a specific example of the present disclosure related to the problem described in the Summary of the Invention.

[0091] Aspects of the present disclosure have been described above with reference to the embodiments. However, the present disclosure is not limited to the above-described embodiments, but various modifications and changes may be made to the embodiments without departing from the scope of the present disclosure. Industrial Applicability

[0092] The technology disclosed herein can be applied to manufacturing industries such as drive devices.

Claims

1. A driving device comprising: A motor having a three-phase coil; an electric storage device; and an inverter configured to convert direct current from the power storage device into three-phase alternating current and supply the three-phase alternating current to the motor, The drive device is programmed to execute a first mode of driving all three phases of the inverter or a second mode of driving two of the three phases of the inverter during at least one of external charging and external power supply, wherein in the external charging, the power supplied from the external power supply device to the neutral point to which the three-phase coil is connected is supplied to the power storage device through voltage conversion of the motor and the inverter, and in the external power supply, the power from the power storage device is supplied to the outside of the drive device via the neutral point through voltage conversion of the inverter and the motor.

2. The driving device according to claim 1, wherein: The drive device is configured to execute the first mode or the second mode based on at least one of information related to the motor, information related to the inverter, information related to the power storage device, information related to the neutral point, and information related to the external environment.

3. The driving device according to claim 2, wherein: The driving device is programmed to perform the staggered driving in the second mode when a supply-related value related to the electric power or current supplied from the external power supply device to the neutral point is equal to or less than a supply threshold value, and to perform the staggered driving in the first mode when the supply-related value is greater than the supply threshold value.

4. The driving device according to claim 3, further comprising: a cooler configured to circulate a cooling medium to the motor, the inverter, and the power storage device, The drive device is programmed to perform the interleaved drive in the first mode when the power storage device is required to increase its temperature and the supply-related value is less than the supply threshold, and the drive device is programmed to perform the interleaved drive in the second mode when the power storage device is required to increase its temperature and the supply-related value is equal to or greater than the supply threshold.

5. The driving device according to claim 3, further comprising: a heater configured to heat a cabin of a vehicle using the motor and the inverter as a heat source, wherein the drive device is programmed to perform the staggered drive in the first mode when heating in the vehicle cabin is required and the supply-related value is less than the supply threshold, and the drive device is programmed to perform the staggered drive in the second mode when heating in the vehicle cabin is required and the supply-related value is equal to or greater than the supply threshold.

6. The driving device according to any one of claims 2 to 5, wherein: The driving device is programmed to perform the interleaved driving in the first mode when the temperature of the inverter is greater than a second temperature threshold.

7. The driving device according to any one of claims 2 to 5, wherein: The driving device is programmed to perform the staggered driving in the first mode when the temperature of the motor is greater than a first temperature threshold, the temperature of the inverter is greater than a second temperature threshold, and the inverter is heated more severely than the motor.

8. The driving device according to any one of claims 2 to 5, wherein: The drive device is programmed to instruct the external power supply device to limit power or current from the external power supply device to the neutral point when the temperature of the motor is greater than the first temperature threshold and / or the temperature of the inverter is greater than the second temperature threshold, compared to when the temperature of the motor is equal to or less than the first temperature threshold and the temperature of the inverter is equal to or less than the second temperature threshold.

9. The driving device according to any one of claims 1 to 5, wherein: The driving device is programmed to perform the interleaved driving in the first mode or the second mode, The driving device is programmed to perform the interleaved driving using two driving phases in the second mode, and the two driving phases are the two phases with the smallest difference in inductance values ​​among the three phases.

10. The driving device according to claim 9, further comprising: a cooler configured to circulate a cooling medium to the motor, the inverter, and the power storage device, The driving device is programmed to perform the interleaved driving in the second mode using two driving phases when the storage device is required to increase its temperature, the two driving phases being the two phases having the largest difference in inductance among the three phases.

11. The driving device according to claim 9, further comprising: a heater configured to heat a cabin of a vehicle using the motor and the inverter as a heat source, The driving device is programmed to perform the interleaved driving in the second mode using two driving phases when heating in the vehicle cabin is required, the two driving phases being the two phases having the largest difference in inductance values ​​among the three phases.

12. The driving device according to claim 9, wherein: The drive device is programmed to set the drive two phases based on the rotational position of the rotor of the electric motor.

13. The driving device according to claim 9, wherein: The driving device is programmed to set the two driving phases based on an amount of change per unit time of a phase current of each phase of the motor when a test current flows through each phase of the motor.

14. A drive device according to any one of claims 1 to 5, wherein: The drive device is programmed to set a target voltage ratio based on which of the first mode and the second mode is selected, and instruct the external power supply device to apply a target voltage based on the voltage of the power storage device and the target voltage ratio to the neutral point from the external power supply device.

15. The driving device according to claim 14, further comprising: a cooler configured to circulate a cooling medium to the motor, the inverter, and the power storage device, The drive device is programmed to set the target voltage ratio based on which of the first mode and the second mode is selected and whether a temperature increase of the power storage device is required.

16. The driving device according to claim 14, further comprising: a heater configured to heat a cabin of a vehicle using the motor and the inverter as a heat source, The driving device is programmed to set the target voltage ratio based on which of the first mode and the second mode is selected and whether heating within the vehicle cabin is required.

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