Drive device

Abstract

To raise the temperature of a power storage device while suppressing an increase in noise and vibration of a motor.SOLUTION: When the temperature rise condition of the power storage device is satisfied, the current advance angle is set so as to achieve both reduction of deterioration of the radial direction forced force and the heat generation amount of the motor and the inverter when the resonance of the motor is the first type resonance excited by the radial direction forced force of the motor, and the current advance angle is set so as to achieve both reduction of deterioration of the circumferential direction forced force and the heat generation amount of the motor and the inverter when the resonance of the motor is the second type resonance excited by the circumferential direction forced force of the motor.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Conventionally, in a motor control device that performs vector control of a motor used to drive a vehicle, when warming up of the battery is required, the q-axis current of the vector control of the motor is set to 0 or to a current value that generates a drive torque that allows the vehicle to creep if braking is released, and a d-axis current that allows the battery to warm up is set; while the vehicle is running, the q-axis current is set according to the required drive torque necessary for vehicle running, and a d-axis current that cooperates with the q-axis current to promote warming up of the battery is set; in either case, the d-axis current is set to increase as the battery temperature decreases. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5259752 Summary of the Invention [Problem to be solved by the invention]

[0004] In the drive device described above, depending on the current advance angle when the battery needs to be warmed up, the motor resonance may be excited by a radial force (electromagnetic force) or a circumferential force of the motor, which may increase the noise and vibration of the motor. The drive device disclosed herein has a primary objective of increasing the temperature of the power storage device while suppressing increases in motor noise and vibration. [Means for solving the problem]

[0005] The drive device of the present disclosure employs the following measures to achieve the above-described primary object. The drive device of the present disclosure is a drive device including a power storage device, a motor, an inverter provided between the power storage device and the motor, a heat transfer device that transfers heat from the motor and / or the inverter to the power storage device, and a control device that controls the inverter using a current advance angle based on a torque command for the motor, wherein, when a temperature rise condition for the power storage device is met, the control device sets the current advance angle if the resonance of the motor is a first type resonance excited by a radial force of the motor, so as to both reduce the deterioration of the radial force and increase the heat generation of the motor and the inverter, and sets the current advance angle if the resonance of the motor is a second type resonance excited by a circumferential force of the motor, so as to both reduce the deterioration of the circumferential force and increase the heat generation of the motor and the inverter.

[0006] In the drive device of the present disclosure, when the temperature rise condition of the power storage device is met, if the motor resonance is a first type resonance excited by a radial force of the motor, the current advance angle is set to achieve both a reduction in deterioration of the radial force and an increase in the amount of heat generated by the motor and the inverter, and if the motor resonance is a second type resonance excited by a circumferential force of the motor, the current advance angle is set to achieve both a reduction in deterioration of the circumferential force and an increase in the amount of heat generated by the motor and the inverter. This makes it possible to raise the temperature of the power storage device while suppressing increases in motor noise and vibration, depending on whether the motor resonance is the first type resonance or the second type resonance. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram of an electric vehicle 10 equipped with a drive device according to an embodiment. [Figure 2] 4 is a flowchart showing an example of a processing routine repeatedly executed by the ECU 50. [Figure 3]10 is an explanatory diagram showing an example of the relationship between the current advance angle θi and the degree of deterioration of the radial and circumferential forces of the stator of the motor 22. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] A mode (embodiment) for carrying out the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic diagram of an electric vehicle 10 equipped with a drive device according to an embodiment of the present disclosure. As shown in the figure, the electric vehicle 10 according to the embodiment includes a motor 22, an inverter 24, a battery 26 as an electricity storage device, a cooling device 40 as a heat transfer device, and an electronic control unit (hereinafter referred to as "ECU") 50 as a control device.

[0009] The motor 22 is configured as a three-phase AC motor and includes a rotor with a permanent magnet embedded in a rotor core and a stator with three-phase (U-phase, V-phase, and W-phase) coils wound around a stator core. The rotor of the motor 22 is connected to a drive shaft 16 that is coupled to the drive wheels 12a and 12b via a differential gear 14. The inverter 24 is connected to a power line 28 (a positive line 28p and a negative line 28n) to which a battery 26 is connected. The inverter 24 includes six switching elements, namely, transistors T11 to T16, and six diodes D11 to D16 connected in parallel to the six transistors T11 to T16, respectively. The transistors T11 to T16 are arranged in pairs, two on the source side and two on the sink side, relative to the positive line 28p and the negative line 28n. Each of the connection points of two pairs of transistors T11-T16 is connected to a three-phase (U-phase, V-phase, W-phase) coil of the motor 22. Therefore, the ECU 50 adjusts the proportion of the on-time of the paired transistors T11-T16, thereby generating a rotating magnetic field in the three-phase coil of the motor 22 and rotating the motor 22 (rotor). The battery 26 is configured as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery. The positive and negative terminals of the battery 26 are connected to a power line 28. A smoothing capacitor 30 is connected to the power line 28. The cooling device 40 has a circulation flow path 42, a radiator 44, and an electric pump 46. The circulation flow path 42 is configured as a flow path for circulating coolant through the motor 22, the inverter 24, the battery 26, and the radiator 44 in this order. The electric pump 46 pumps (circulates) the coolant through the circulation flow path 42. The circulation flow path 42 may be configured as a flow path for circulating the cooling water through the inverter 24, the motor 22, the battery 26, and the radiator 44 in this order.

[0010] The ECU 50 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, as well as various drive circuits and logic ICs. The ECU 50 receives signals from various sensors. For example, the ECU 50 receives the rotational position θm of the rotor of the motor 22 from the rotational position sensor 22a and the phase currents Iu, Iv, and Iw of the motor 22 from the current sensors 22u, 22v, and 22w. The ECU 50 also receives the voltage Vb of the battery 26 from the voltage sensor 26v, the current Ib of the battery 26 from the current sensor 26i, and the temperature Tb of the battery 26 from the temperature sensor 26t. The ECU 50 also receives the voltage VH of the capacitor 30 from the voltage sensor 30v and the temperature Tc of the cooling water in the circulation flow path 42 of the cooling device 40 from the temperature sensor 48. Also input to the ECU 50 are an on / off signal from a power switch 60, the operating position of a shift lever 61 (shift position SP) from a shift position sensor 62, the depression amount of an accelerator pedal 63 (accelerator opening Acc) from an accelerator pedal position sensor 64, the depression amount of a brake pedal 65 (brake pedal position BP) from a brake pedal position sensor 66, and a vehicle speed V from a vehicle speed sensor 67. The ECU 50 outputs switching control signals to transistors T11 to T16 of the inverter 24 and a control signal to the electric pump 46. The ECU 50 calculates the electrical angle θe and rotation speed Nm of the motor 22 based on the rotational position θm of the rotor of the motor 22, and calculates the charge storage rate SOC of the battery 26 based on the integrated value of the current Ib of the battery 26.

[0011] In the electric vehicle 10 of this embodiment configured in this manner, the ECU 50 sets the required torque Td* required for driving (required of the drive shaft 16) based on the accelerator opening Acc and the vehicle speed V, sets the torque command Tm* for the motor 22 so that the vehicle drives with the set required torque Td*, and performs switching control of the transistors T11 to T16 of the inverter 24 based on the set torque command Tm*.

[0012] Here, the control of the inverter 24 will be described. The ECU 50 performs coordinate conversion (three-phase to two-phase conversion) of the phase currents Iu, Iv, and Iw of the motor 22 into d-axis and q-axis currents Id and Iq using the electrical angle θe of the motor 22. Next, the ECU 50 sets a current lead angle θi and an effective current value Ir based on a torque command Tm* of the motor 22, and sets d-axis and q-axis current commands Id* and Iq* based on the set current lead angle θi and effective current value Ir. The current lead angle θi is the angle (amount of lead angle) relative to the q-axis of a current command vector having d-axis and q-axis current commands Id* and Iq* as components in a dq coordinate system, and the effective current value Ir is the square root of the sum of the square of the d-axis current command Id* and the square of the q-axis current command Iq*. Then, d-axis and q-axis voltage commands Vd*, Vq* are calculated by current feedback control so that the differences between the d-axis and q-axis current commands Id*, Iq* and the currents Id, Iq are canceled out. In addition, the d-axis and q-axis voltage commands Vd*, Vq* are coordinate-converted (two-phase to three-phase conversion) to voltage commands Vu*, Vv*, Vw* for each phase using the electrical angle θe of the motor 22, and PWM signals for the transistors T11 to T16 are generated by comparing these voltage commands Vu*, Vv*, Vw with the carrier voltage, and the generated PWM signals for the transistors T11 to T16 are used to control the switching of the transistors T11 to T16.

[0013] Next, the operation of the electric vehicle 10 according to this embodiment, particularly the process for setting the current advance angle θi and the effective current value Ir, will be described. FIG. 2 is a flowchart showing an example of a process routine repeatedly executed by the ECU 50. When this routine is executed, the ECU 50 first determines whether a temperature increase condition for the battery 26 is met (step S100). Here, the temperature increase condition for the battery 26 is met, for example, when the temperature Tb of the battery 26 is equal to or lower than a threshold value Tblo, or when a user operation (such as a switch operation) requests that the battery 26 be increased in temperature.

[0014] If it is determined in step S100 that the temperature rise condition of the battery 26 is not satisfied, the current advance angle θi is set to a value θi1 (step S140), and the effective current value Ir is set based on the set current advance angle θi and the torque command Tm* (step S190), and this routine ends. The value θi1 is determined, for example, as the value that minimizes the effective current value Ir among the combinations of the current advance angle θi and the effective current value Ir for outputting the torque command Tm* from the motor 22.

[0015] If it is determined in step S100 that the temperature rise condition of the battery 26 is satisfied, it is then determined whether or not a noise vibration (NV) condition, in which noise and vibration of the motor 22 become a problem, is satisfied (step S110). The NV condition is satisfied, for example, when the rotation speed Nm of the motor 22 is within a predetermined rotation speed range. The predetermined rotation speed range includes first, second, and third rotation speed ranges. The first rotation speed range is a rotation speed range in which a radial forcing force (electromagnetic forcing force) of the stator of the motor 22 excites motor resonance (such as stator zeroth-order resonance, first-order resonance, second-order resonance, fourth-order resonance, and stator bending resonance, hereinafter referred to as "radial force excitation resonance"). The second rotation speed range is a rotation speed range in which a circumferential forcing force of the stator excites motor resonance (such as stator torsional resonance, hereinafter referred to as "circumferential force excitation resonance"). The third rotation speed range is a rotation speed range other than the first and second rotation speed ranges in which noise and vibration of the motor 22 become an issue. The first, second, and third rotation speed ranges depend on the specifications of the motor 22 and are determined in advance through experiments, analysis, etc.

[0016] If it is determined in step S110 that the NV problem condition is not satisfied, the current advance angle θi is set to a value θi2 (step S150), the effective current value Ir is set based on the set current advance angle θii and the torque command Tm* (step S190), and this routine ends. The value θi2 is determined, for example, as a value that increases the d-axis current compared to the value θi1 of the combination of the current advance angle θi and the effective current value Ir for outputting the torque command Tm* from the motor 22, thereby increasing the amount of heat generated by the motor 22 and the inverter 24. This increases the amount of heat generated by the motor 22 and the inverter 24, allowing the temperature of the battery 26 to be raised via the cooling device 40.

[0017] If it is determined in step S110 that the NV problem condition is met, it is determined whether the rotation speed Nm of the motor 22 is within a first rotation speed range (a rotation speed range in which radial force excitation resonance is excited) (step S120), and it is also determined whether the rotation speed Nm of the motor 22 is within a second rotation speed range (a rotation speed range in which circumferential force excitation resonance is excited) (step S130). If it is determined in step S120 that the rotation speed Nm of the motor 22 is within the first rotation speed range, the current advance angle θi is set to a value θi3 (step S160). If it is determined in step S130 that the rotation speed Nm of the motor 22 is within the second rotation speed range, the current advance angle θi is set to a value θi4 (step S170). If it is determined in steps S120 and S130 that the rotation speed Nm1 of the motor 22 is outside the first or second rotation speed range (within the third rotation speed range), the current advance angle θi is set to a value θi5 (step S180). The values ​​θai3 to θi5 will be described later. After the current advance angle θi is set in this manner, the effective current value Ir is set based on the set current advance angle θii and torque command Tm* (step S190), and this routine ends.

[0018] 3 is an explanatory diagram showing an example of the relationship between the current advance angle θi and the degree of deterioration of the radial coercive force and the circumferential coercive force of the stator of the motor 22. This relationship varies depending on the specifications of the motor 22, etc. In the example of FIG. 3, the radial coercive force of the stator decreases and then increases as the current advance angle θi increases, and the circumferential coercive force of the stator increases and then decreases as the current advance angle θi increases. For this reason, when the rotation speed Nm of the motor 22 is within a first rotation speed range (a rotation speed range in which radial force excitation resonance is excited), it is preferable to set the current advance angle θi to a value greater than θi1 and smaller than θi2 in order to reduce (improve) the degree of deterioration of the radial coercive force compared to when the current advance angle θi is θi2. Furthermore, when the rotation speed Nm of the motor 22 is within a second rotation speed range (a rotation speed range in which circumferential force excitation resonance is excited), it is preferable to set the current advance angle θi to be larger than the value θi2 in order to reduce the degree of deterioration of the circumferential force compared to when the current advance angle θi is the value θi2. Based on this, the values ​​θi3 and θi4 are determined. The value θi5 is set appropriately. In this embodiment, the value θi5 is determined to be larger than the value θi1 and smaller than the values ​​θi2, θi3, and θi4.

[0019] In the drive device 20 mounted on the electric vehicle 10 of the embodiment described above, when the temperature-raising condition for the battery 26 is satisfied and the NV problem condition is satisfied, if the rotation speed Nm of the motor 22 is within a first rotation speed range (a rotation speed range in which radial force excitation resonance is excited), the current advance angle θi* is set so as to both reduce deterioration of the radial force and increase the heat generation amount of the motor 22 and the inverter 24, and if the rotation speed Nm of the motor 22 is within a second rotation speed range (a rotation speed range in which circumferential force excitation resonance is excited), the current advance angle θi* is set so as to both reduce deterioration of the circumferential force and increase the heat generation amount of the motor 22 and the inverter 24. As a result, the battery 26 can be heated while suppressing increases in noise and vibration of the motor 22, depending on whether the resonance of the motor 22 is radial force excitation resonance or circumferential force excitation resonance.

[0020] In the above-described embodiment, the battery 26 is used as the power storage device, but this is not limiting. For example, a capacitor or the like may be used as the power storage device.

[0021] In the above-described embodiment, the drive unit is mounted on an electric vehicle 10 equipped with a motor 22, but is not limited to this. For example, the drive unit may be mounted on a hybrid vehicle equipped with an engine in addition to a motor, or on a fuel cell vehicle equipped with a fuel cell in addition to a motor. The drive unit may also be mounted on a moving object other than a vehicle or on stationary construction equipment.

[0022] The correspondence between the main elements of the embodiment and the main elements of the invention described in the "Means for Solving the Problem" section will be described below. In the embodiment, the battery 26 corresponds to the "electricity storage device," the motor 22 corresponds to the "motor," the inverter 24 corresponds to the "inverter," the cooling device 40 corresponds to the "heat transfer device," and the ECU 50 corresponds to the "control device."

[0023] The correspondence between the main elements of the embodiments and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, since the embodiments are examples for specifically explaining the mode for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the embodiments are merely specific examples of the invention described in the "Means for Solving the Problem" section.

[0024] The above describes the forms for implementing the present disclosure using embodiments, but the present disclosure is not limited to these embodiments in any way, and it goes without saying that the present disclosure can be implemented in various forms within the scope that does not deviate from the gist of the present disclosure. [Industrial Applicability]

[0025] The present disclosure is applicable to industries such as the drive device manufacturing industry. [Explanation of symbols]

[0026] 10 electric vehicle, 12a, 12b drive wheels, 14 differential gear, 16 drive shaft, 20 drive unit, 22 motor, 22a rotational position sensor, 22u, 22v, 22w, 26i current sensor, 24 inverter, 26 battery, 26t, 48 temperature sensor, 26v, 30v voltage sensor, 28n negative line, 28p positive line, 30 capacitor, 40 cooling device (heat transfer device), 42 circulation flow path, 44 radiator, 46 electric pump, 50 ECU (control device), D11 to D16 diodes, T11 to T16 transistors.

Claims

[Claim 1] A drive device including: a power storage device; a motor; an inverter provided between the power storage device and the motor; a heat transfer device that transfers heat from the motor and / or the inverter to the power storage device; and a control device that controls the inverter using a current advance angle based on a torque command of the motor, When a temperature rise condition of the power storage device is satisfied, if the resonance of the motor is a first type resonance excited by a radial force of the motor, the control device sets the current advance angle so as to achieve both a reduction in deterioration of the radial force and an increase in heat generation of the motor and the inverter, and if the resonance of the motor is a second type resonance excited by a circumferential force of the motor, the control device sets the current advance angle so as to achieve both a reduction in deterioration of the circumferential force and an increase in heat generation of the motor and the inverter. Drive unit.

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