JP2020137234A - Drive device - Google Patents

Abstract

To suppress an increase in torque fluctuation of a motor.SOLUTION: When switching an inverter from pulse width modulation control with a fixed modulation factor to rectangular wave control, the control device controls the inverter while gradually increasing a modulation factor for control. Specifically, when a difference between the modulation factor for control and a pulse reduction modulation factor at which the number of pulses per one electric cycle of a motor decreases is larger than a predetermined value, the control device sets a voltage phase command on the basis of a torque command and the modulation factor for control, and controls the inverter on the basis of the voltage phase command and the modulation factor for control. When a difference between the modulation factor for control and the pulse reduction modulation factor is the predetermined value or smaller, the control device sets the voltage phase command in consideration of an amount of change in an influence of a dead time based on the amount of reduction in the number of pulses at the pulse reduction modulation factor, in addition to the torque command and the modulation factor for control, and controls the inverter on the basis of the voltage phase command and the modulation factor for control.SELECTED DRAWING: Figure 2

Description

The present invention relates to a drive device.

Conventionally, as a drive device of this type, in a drive device that controls an inverter that drives a motor by switching between PWM control and square wave control, when switching from PWM control to square wave control, the voltage waveform of PWM control is used. It is proposed to find the phase and amplitude, find the phase of a square wave that produces a torque equivalent to the current motor torque, and change the phase and amplitude from the PWM-controlled voltage waveform toward the square wave simultaneously and continuously. (See, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 11-285288

In the above-mentioned drive device, when switching from PWM control to square wave control, the phase and amplitude are changed simultaneously and continuously from the voltage waveform of PWM control toward the square wave, so that the torque fluctuation of the motor may become large. is there. This is because the relationship between the amplitude and the phase, which are equal torques of the motor, is generally non-linear. Further, in the above-mentioned drive device, when the modulation factor is gradually increased in order to switch from PWM control to square wave control, the number of pulses in one electric cycle of the motor is reduced for switching of a plurality of switching elements of the inverter. When the number of dead times provided decreases, the influence of the dead times on the actual voltage applied to the motor changes, and the torque fluctuation of the motor may increase.

The main object of the drive device of the present invention is to suppress a large torque fluctuation of the motor.

The drive device of the present invention has adopted the following means in order to achieve the above-mentioned main object.

The drive device of the present invention
With the motor
An inverter that drives the motor by switching a plurality of switching elements,
A control device that switches and controls the inverter between pulse width modulation control and square wave control based on the torque command of the motor.
It is a drive device equipped with
When switching from the pulse width modulation control having a fixed modulation factor to the rectangular wave control, the control device
While gradually increasing the control modulation factor
When the difference between the control modulation factor and the pulse reduction modulation rate at which the number of pulses per electric cycle of the motor decreases is larger than a predetermined value, the voltage phase is based on the torque command and the control modulation factor. A command is set, and the inverter is controlled based on the voltage phase command and the control modulation factor.
When the difference between the control modulation factor and the pulse reduction modulation factor is equal to or less than the predetermined value, it is based on the reduction amount of the number of pulses at the pulse reduction modulation factor in addition to the torque command and the control modulation factor. The voltage phase command is set in consideration of the amount of change in the influence of the dead time, and the inverter is controlled based on the voltage phase command and the control modulation factor.
The gist is that.

In the drive device of the present invention, when switching from pulse width modulation control having a fixed modulation factor to rectangular wave control, the inverter is controlled while gradually increasing the control modulation factor. Specifically, when the difference between the control modulation factor and the pulse reduction modulation rate at which the number of pulses per electric cycle of the motor decreases is larger than a predetermined value, the voltage phase is based on the torque command and the control modulation factor. A command is set, and the inverter is controlled based on the voltage phase command and the control modulation factor. When the difference between the control modulation factor and the pulse reduction modulation factor is less than a predetermined value, the amount of change in the effect of dead time based on the reduction amount of the number of pulses in the pulse reduction modulation factor in addition to the torque command and the control modulation factor. The voltage phase command is set in consideration of the above, and the inverter is controlled based on the voltage phase command and the control modulation factor. Here, the "change amount of the influence of the dead time" means the change amount of the influence of the dead time provided for switching of a plurality of switching elements of the inverter on the actual voltage applied to the motor. With such control, when switching from pulse width modulation control with a fixed modulation factor to square wave control, especially when the control modulation factor straddles the pulse reduction modulation factor and the number of pulses per electric cycle decreases, the motor It is possible to suppress a large fluctuation in the torque of.

In such a drive device of the present invention, the control device is based on the torque command and the control modulation factor, or based on the torque command, the control modulation factor, and the amount of change in the influence of the dead time. Then, the feed forward term of the voltage phase command is set, the feedback term of the voltage phase command is set so that the difference between the torque command and the torque of the motor is canceled, and the feed forward term and the feedback term are set. The voltage phase command may be set as the sum of.

It is a block diagram which shows the outline of the structure of the electric vehicle 20 which mounts the drive device as one Example of this invention. It is a flowchart which shows an example of the control routine executed by an electronic control unit 50. It is explanatory drawing which shows an example of the PWM signal of the transistor T11 of each modulation factor Vr. It is explanatory drawing which shows an example of the relationship between the modulation factor Vr and the number of pulses Np. It is explanatory drawing which shows an example of the relationship between the voltage command in a dq coordinate system, the actual voltage, and the influence of a dead time. It is a flowchart which shows an example of the control routine of a modification.

Next, a mode for carrying out the present invention will be described with reference to Examples.

FIG. 1 is a configuration diagram showing an outline of a configuration of an electric vehicle 20 equipped with a drive device as an embodiment of the present invention. As shown in the figure, the electric vehicle 20 of the embodiment includes a motor 32, an inverter 34, a battery 36 as a power storage device, and an electronic control unit 50. The "driving device" of the embodiment mainly corresponds to the motor 32, the inverter 34, and the electronic control unit 50.

The motor 32 is configured as a synchronous motor generator, and includes a rotor in which a permanent magnet is embedded in a rotor core and a stator in which a three-phase coil is wound around a stator core. The rotor of the motor 32 is connected to a drive shaft 26 connected to the drive wheels 22a and 22b via a differential gear 24.

The inverter 34 is used to drive the motor 32. The inverter 34 is connected to the battery 36 via a power line 38, and six diodes D11 to six transistors T11 to T16 as six switching elements and six diodes D11 to each of the six transistors T11 to T16 are connected in parallel. It has D16. Two transistors T11 to T16 are arranged in pairs so as to be on the source side and the sink side with respect to the positive electrode bus and the negative electrode bus of the power line 38, respectively. Further, each of the three-phase coils (U-phase, V-phase, and W-phase coils) of the motor 32 is connected to each of the connection points between the transistors paired with the transistors T11 to T16. Therefore, when a voltage is applied to the inverter 34, the electronic control unit 50 adjusts the on-time ratio of the transistors T11 to T16 paired with the inverter 34, so that the rotating magnetic field is applied to the three-phase coil of the motor 32. Is formed, and the rotor of the motor 32 is rotationally driven.

The battery 36 is configured as, for example, a lithium ion secondary battery or a nickel hydrogen secondary battery, and is connected to the inverter 34 via the power line 38 as described above. A smoothing capacitor 39 is attached to the positive electrode bus and the negative electrode bus of the power line 38.

The electronic control unit 50 is configured as a microprocessor centered on a CPU 51, and includes a ROM 52 for storing a processing program, a RAM 53 for temporarily storing data, and an input / output port in addition to the CPU 51. Signals from various sensors are input to the electronic control unit 50 via input ports. The signals input to the electronic control unit 50 include, for example, the rotation position θm of the rotor of the motor 32 from the rotation position detection sensor (for example, resolver) 32a that detects the rotation position of the rotor of the motor 32, and the rotation position θm of the motor 32. Examples of the U-phase and V-phase currents Iu and Iv of the motor 32 from the current sensors 32u and 32v attached to the U-phase and V-phase can be mentioned. Further, the voltage Vb of the battery 36 from the voltage sensor 36a attached between the terminals of the battery 36, the current Ib of the battery 36 from the current sensor 36b attached to the output terminal of the battery 36, and the temperature attached to the battery 36. The temperature Tb of the battery 36 from the sensor 36c and the voltage VH of the smoothing capacitor 39 (power line 38) from the voltage sensor 39a attached between the terminals of the smoothing capacitor 39 can also be mentioned. Further, the ignition signal from the ignition switch 60, the shift position SP from the shift position sensor 62 that detects the operation position of the shift lever 61, and the accelerator opening Acc from the accelerator pedal position sensor 64 that detects the amount of depression of the accelerator pedal 63. , The brake pedal position BP from the brake pedal position sensor 66 that detects the depression amount of the brake pedal 65, and the vehicle speed V from the vehicle speed sensor 68 can also be mentioned.

From the electronic control unit 50, switching control signals and the like to the transistors T11 to T16 of the inverter 34 are output via the output port. The electronic control unit 50 calculates the electric angle θe, the electric angular velocity ωe, and the rotation speed Nm of the motor 32 based on the rotation position θm of the rotor of the motor 32 from the rotation position detection sensor 32a. Further, the electronic control unit 50 calculates the storage ratio SOC of the battery 36 based on the integrated value of the current Ib of the battery 36 from the current sensor 36b, and the calculated storage ratio SOC and the temperature of the battery 36 from the temperature sensor 36c. The input / output restrictions Win and Wout of the battery 36 are set based on Tb. Here, the storage ratio SOC is the ratio of the capacity of the power that can be discharged from the battery 36 to the total capacity of the battery 36, and the input / output restrictions Win and Wout are the allowable input / output powers that may charge and discharge the battery 36. is there.

In the electric vehicle 20 of the embodiment configured in this way, the electronic control unit 50 sets the required torque Td * required for the drive shaft 26 based on the accelerator opening degree Acc and the vehicle speed V, and sets the required torque Td *. The torque command Tm * of the motor 32 is set so that is output to the drive shaft 26, and the switching control of the transistors T11 to T16 of the inverter 34 is performed so that the motor 32 is driven by the torque command Tm *.

Here, the control of the inverter 34 will be described. In the embodiment, the electronic control unit 50 controls the inverter 34 by switching between pulse width modulation (PWM) control and square wave control. The PWM control is a control for controlling the inverter 34 so that a pseudo three-phase AC voltage or an overmodulation voltage is applied to the motor 32, and the square wave control is a control for applying the square wave voltage to the motor 32. This is a control for controlling the inverter 34. In PWM control, the modulation factor Vr is less than 0 to 0.78, and in rectangular wave control, the modulation factor Vr is 0.78. The PWM control includes a variable PWM control in which the modulation factor Vr is variable and a fixed PWM control in which the modulation factor Vr is fixed. Since the variable PWM control does not form the core of the present invention, detailed description thereof will be omitted.

Next, the operation of the electric vehicle 20 of the embodiment configured in this way, particularly the operation when the inverter 34 is controlled by the fixed PWM control (including the case of switching from the fixed PWM control to the rectangular wave control) will be described. FIG. 2 is a flowchart showing an example of a control routine executed by the electronic control unit 50. This routine is executed when the inverter 34 is controlled by fixed PWM control.

When the switching control routine of FIG. 2 is executed, the electronic control unit 50 first receives the torque command Tm * of the motor 32, the estimated torque Tmes, the electric angular velocity ωe, the number of synchronizations Ns, the carrier frequency fc, and the power line 38. Data such as voltage VH is input (step S100).

Here, the torque command Tm * of the motor 32 is assumed to input the value set as described above. The estimated torque Tmes of the motor 32 uses the electric angle θe of the motor 32 from the rotation position detection sensor 32a to set the U-phase and V-phase currents Iu and Iv of the motor 32 from the current sensors 32u and 32v on the d-axis and q-axis. Coordinate conversion (3-phase-2 phase conversion) was performed on the currents Id and Iq of the above, and the values estimated based on the currents Id and Iq of the d-axis and the q-axis were input.

For the electric angular velocity ωe of the motor 32, a value calculated based on the rotation position θm of the rotor of the motor 32 from the rotation position detection sensor 32a is input. The synchronization number Ns is the number of cycles of the triangular wave of one electric cycle of the motor 32, and a value set based on the electric angular velocity ωe (rotation speed Nm) of the motor 32 is input. The carrier frequency fc is a frequency of a triangular wave, and a value calculated based on the electric angular velocity ωe (rotation speed Nm) of the motor 32 and the synchronization number Ns is input. The voltage VH of the power line 38 is assumed to input the value detected by the current sensor 39a.

When the data is input in this way, it is determined whether or not the request for switching from the fixed PWM control to the rectangular wave control has been made (step S110). In this process, for example, it is determined whether or not the electric sixth power fluctuation of the motor 32 goes out of the rotation speed region where LC resonance of the electric system can be generated.

When it is determined that the request for switching from the fixed PWM control to the rectangular wave control has not been made, a predetermined modulation factor Vrset is set in the control modulation factor Vr * (step S120). Here, the predetermined modulation factor Vr is defined as a modulation factor capable of suppressing electric sixth-order power fluctuations in an electric circuit having a motor 32, an inverter 34, a battery 36, a power line 38, and a capacitor 39, for example, 0.70 to 0.70. About 0.72 is used.

When the control modulation factor Vr * is set in this way, the voltage VH of the power line 38 is multiplied by the control modulation factor Vr * to calculate the voltage effective value command Vef * (step S130). Then, the voltage phase command is given using the equation (1) defined as the relationship between the torque command Tm * of the motor 32, the electric angular velocity ωe of the motor 32, the control modulation factor Vr *, the voltage VH of the power line 38, and the voltage phase φv. The feed forward term φvff of φv * is calculated (step S180). Here, in the equation (1), "P" is the logarithm of the motor 32, "φa" is the counter electromotive voltage constant, and "Ld" and "Lq" are the inductances of the d-axis and the q-axis, respectively. is there.

Subsequently, the feedback term φvfb of the voltage phase command φv * is calculated by the equation (2) using the torque command Tm * and the estimated torque Tmes of the motor 32 (step S220). Here, the equation (2) is a relational expression in the torque feedback control for canceling the difference between the estimated torque Tmes of the motor 32 and the torque command Tm *, and in the equation (2), "kp" is the gain of the proportional term. And "ki" is the gain of the integral term.

Then, the voltage phase command φv * is calculated as the sum of the feed forward term φvff and the feedback term φvfb (step S230), and the voltage command Vu * of each phase is calculated based on the voltage effective value command Vef * and the voltage phase command φv *. Vv * and Vw * are set (step S240), and the PWM signals of the transistors T11 to T16 of the inverter 34 are generated by comparing the set voltage commands Vu *, Vv *, Vw * with the triangular wave (step S240). S250), this routine is terminated. When the PWM signals of the transistors T11 to T16 are generated in this way, the switching control of the transistors T11 to T16 is performed using the PWM signals.

When it is determined in step S110 that the request for switching from the fixed PWM control to the rectangular wave control has been made, the value obtained by adding the predetermined value ΔVr to the previous control modulation factor (previous Vr *) is added to the new control modulation factor. Set to Vr * (step S140). Here, for the predetermined value ΔVr, for example, 0.001, 0.002, 0.005, or the like is used. In this way, each time the process of step S140 is repeatedly executed, the control modulation factor Vr * is changed from the fixed PWM control modulation factor Vr (for example, 0.70) to the square wave control modulation factor Vr (0.78). Gradually get closer to.

Subsequently, the voltage VH of the power line 38 is multiplied by the control modulation factor Vr * to calculate the voltage effective value command Vef * (step S150). Then, based on the synchronization number Ns and the control modulation factor Vr *, the pulse reduction modulation rate Vrpdn at which the number of pulses per electric cycle of the motor 32 is reduced in PWM control and the pulse reduction number Npdn at that time are set. (Step S160).

FIG. 3 is an explanatory diagram showing an example of the PWM signal of the transistor T11 of each modulation factor Vr, and FIG. 4 is an explanatory diagram showing an example of the relationship between the modulation factor Vr and the number of pulses Np. As can be seen from FIG. 3, as the modulation factor Vr increases, the number of pulses Np of the PWM signal of the transistor T11 decreases. The same applies to the transistors T12 to T16. The pulse number Np of the PWM signal of the transistors T11 to T16 corresponding to each modulation factor Vr differs depending on the synchronization number Ns. Based on these, the relationship between the modulation factor Vr and the number of pulses Np as shown in FIG. 4 can be determined in advance by experiments and analysis. As shown in FIG. 4, the pulse number Np gradually decreases from the synchronization number Ns to the value 1 (pulse number Np in the square wave control) as the modulation factor Vr increases. Therefore, in FIG. 4, there are a plurality of combinations of the pulse reduction modulation factor Vrpdn and the pulse reduction number Npdn. Based on this, in the embodiment, the pulse reduction modulation rate Vrpdn and the pulse reduction number Npdn are the synchronization number Ns, the control modulation rate Vr *, the pulse reduction modulation rate Vrpdn closest to the control modulation rate Vr *, and their respective. The relationship between the pulse reduction number Npdn corresponding to the pulse reduction modulation rate Vrpdn and the pulse reduction number Npdn is determined and stored in the ROM 52 as a map, and when the synchronization number Ns and the control modulation factor Vr * are given, the corresponding pulse reduction is performed from this map. The modulation factor Vrpdn and the pulse reduction number Npdn were derived and set.

Next, the absolute value of the value obtained by subtracting the pulse reduction modulation factor Vrpdn from the control modulation factor Vr * is compared with the threshold value Vrref (step S170). Here, the threshold value Vrref is a threshold value for determining whether or not the control modulation factor Vr * is in the vicinity of the pulse reduction modulation factor Vrpdn, and for example, 0.005, 0.010, 0.015, etc. are used. Be done.

When the absolute value of the value obtained by subtracting the pulse reduction modulation rate Vrpdn from the control modulation rate Vr * in step S170 is larger than the threshold voltage Vrref, it is determined that the control modulation rate Vr * is not near the pulse reduction modulation rate Vrpdn, and the above description is performed. By the processing of steps S180 and S220 to S250, each calculation of the feed forward term φvff, the feedback term φvfb, the voltage phase command φv *, the voltage commands Vu *, Vv *, Vw * of each phase, and the transistors T11 to the inverter 34 The PWM signal of T16 is generated, and this routine is terminated.

When the absolute value of the value obtained by subtracting the pulse reduction modulation rate Vrpdn from the control modulation factor Vr * in step S170 is equal to or less than the threshold value Vrref, it is determined that the control modulation factor Vr * is near the pulse reduction modulation rate Vrpdn, and the pulse is reduced. The amount of change ΔVdt due to the influence of the dead time is calculated based on the number Npdn (step S190).

Here, the change amount ΔVdt of the influence of the dead time means the change amount of the influence of the dead time provided for switching the transistors T11 to T16 of the inverter 34 on the actual voltage applied to the motor 32. FIG. 5 is an explanatory diagram showing an example of the relationship between the voltage command, the actual voltage, and the influence of the dead time in the dq coordinate system. When a dead time is provided, the effect causes a discrepancy between the voltage command and the actual voltage, as shown in the figure. Through experiments and analysis, the inventors have found that when the number of pulses Np decreases and the number of dead times decreases, the effect of the dead time, that is, the deviation between the voltage command and the actual voltage becomes smaller. The effect of dead time when the modulation factor Vr is small and there is no pulse omission (when the number of pulses Np is equal to the number of synchronizations Ns) Vdt0 is an equation (when the voltage VH of the power line 38, the number of synchronizations Ns, and the carrier frequency fc are used. It is represented by 3). In equation (3), "Td" is the dead time. On the other hand, the effect Vdt1 of the dead time when the modulation factor Vr is large to some extent and pulse drop occurs (when the pulse number Np is a value Np1 smaller than the synchronization number Ns) is expressed by the equation (4). Therefore, the amount of change ΔVdt of the influence of the dead time when the number of pulses Np changes from the value Np2 of the number of synchronizations Ns or less to the value Np3 less than that is expressed by the equation (5). In this equation (5), since "Np3-Np2" has a negative value, the amount of change ΔVdt due to the influence of the dead time has a negative value. By replacing "Np3-Np2" in the equation (5) with a value obtained by multiplying the pulse reduction number Npdn by "-1", the change amount ΔVdt of the influence of the dead time corresponding to the pulse reduction number Npdn can be calculated. ..

Subsequently, in order to suppress the influence of the change amount ΔVdt of the influence of the dead time by multiplying the inverted sign of the change amount ΔVdt of the influence of the dead time by the correction coefficient k larger than the value 0 and not more than the value 1. The dead time correction amount ΔVdtad of is calculated (step S200). Here, the correction coefficient k is set so as to gradually decrease from the value 1 to the value 0 as the control modulation factor Vr * increases.

Then, the equation (6) defined as the relationship between the torque command Tm * of the motor 32, the electric angular velocity ωe of the motor 32, the control modulation factor Vr *, the voltage VH of the power line 38, the voltage phase φv, and the dead time correction amount ΔVdtad. Is used to calculate the feed forward term φvff of the voltage phase command φv * (step S180). Here, the formula (6) corresponds to the one in which "VH x Vr *" in the formula (1) is replaced with "VH x Vr * + ΔVdtad". Then, by the processing of steps S220 to S250 described above, each calculation of the feedback term φvfb, the voltage phase command φv *, the voltage commands Vu *, Vv *, Vw * of each phase, and the PWM of the transistors T11 to T16 of the inverter 34 are performed. Generates a signal and ends this routine.

By such control, when the control modulation factor Vr * (modulation factor Vr) is gradually increased, the torque fluctuation of the motor 32 becomes large when the number of pulses Np decreases across the pulse reduction modulation factor Vrpdn. Can be suppressed.

In the drive device mounted on the electric vehicle 20 of the above-described embodiment, when switching from the fixed PWM control to the square wave control, the inverter 34 is controlled while gradually increasing the control modulation factor Vr *. Specifically, when the absolute value of the value obtained by subtracting the pulse reduction modulation factor Vrpdn from the control modulation factor Vr * is larger than the threshold voltage Vrref, it is based on the torque command Tm * of the motor 32 and the control modulation factor Vr *. The voltage phase command φv * is set, and the inverter 34 is controlled based on the set voltage phase command φv * and the voltage effective value command Vef * based on the control modulation factor Vr *. When the absolute value of the value obtained by subtracting the pulse reduction modulation rate Vrpdn from the control modulation rate Vr * is equal to or less than the threshold voltage Vrref, the pulse reduction modulation rate Vrpdn is used in addition to the torque command Tm * of the motor 32 and the control modulation rate Vr *. The voltage phase command φv * is set in consideration of the change amount ΔVdt of the influence of the dead time based on the pulse reduction number Npdn of, and the voltage effective value command Vef * based on the set voltage phase command φv * and the control modulation factor Vr *. The inverter 34 is controlled based on the above. As a result, when switching from fixed PWM control to square wave control, the torque fluctuation of the motor 32 becomes large, especially when the control modulation factor Vr * straddles the pulse reduction modulation factor Vrpdn and the pulse number Np decreases. Can be suppressed.

In the drive device mounted on the electric vehicle 20 of the embodiment, the correction coefficient k used for calculating the dead time correction amount ΔVdtad gradually decreases from the value 1 to the value 0 as the control modulation factor Vr * increases. Although the value is set, a constant value larger than the value 0 and less than or equal to the value 1 may be set regardless of the control modulation factor Vr *.

In the drive device mounted on the electric vehicle 20 of the embodiment, the electronic control unit 50 executes the control routine of FIG. 2, but instead of this, the control routine of FIG. 6 may be executed. .. The control routine of FIG. 6 is the same as the control routine of FIG. 2 except that the process of step S300 is executed instead of the process of steps S160 to S210. Therefore, the same process is assigned the same step number, and detailed description thereof will be omitted.

In the control routine of FIG. 6, when the voltage effective value command Vef * is set in step S130 or step S150, the electronic control unit 50 sets the torque command Tm * of the motor 32, the electric angular velocity ωe, the control modulation factor Vr *, and the voltage VH. , The feed forward term φvff of the voltage phase command φv * is set based on the synchronization number Ns (step S300), and the processes after step S220 are executed. In this modification, the feed-forward term φvff is a map in which the relationship between the torque command Tm * of the motor 32, the electric angular velocity ωe, the control modulation factor Vr *, the voltage VH, the synchronization number Ns, and the feed-forward term φvff is predetermined. When the torque command Tm * of the motor 32, the electric angular velocity ωe, the control modulation factor Vr *, the voltage VH, and the synchronization number Ns are given in the ROM 52, the corresponding feed forward term φvff is derived from this map. It was supposed to be set. In this map, the pulse reduction modulation factor Vrpdn (at least one) and the pulse reduction number Npdn are determined by the synchronization number Ns, and the amount of change in the influence of the dead time according to the equation (5) ΔVdt (see the equation (5)). As a result, it is created based on the fact that the dead time correction amount ΔVdtad is determined, and that the feed forward term φvff is determined by the equations (1) and (6). By such a method, the feed forward term φvff can be set more easily.

In the drive device mounted on the electric vehicle 20 of the embodiment, the battery 36 is used as the power storage device, but a capacitor may be used.

In the embodiment, the drive device is mounted on the electric vehicle 20 including the motor 32 and the inverter 34. However, it may be in the form of a drive device mounted on a hybrid vehicle including an engine in addition to the motor 32 and the inverter 34, or as a drive device mounted on a moving body such as a vehicle, a ship, or an aircraft other than the automobile. Alternatively, it may be in the form of a drive device mounted on non-moving equipment such as construction equipment.

The correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem will be described. In the embodiment, the motor 32 corresponds to the "motor", the inverter 34 corresponds to the "inverter", and the electronic control unit 50 corresponds to the "control device".

As for the correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem, the invention described in the column of means for solving the problem in the examples is carried out. Since it is an example for specifically explaining the form for solving the problem, the elements of the invention described in the column of means for solving the problem are not limited. That is, the interpretation of the invention described in the column of means for solving the problem should be performed based on the description in the column, and the examples are the inventions described in the column of means for solving the problem. It is just a concrete example.

Although the embodiments for carrying out the present invention have been described above with reference to Examples, the present invention is not limited to these Examples, and various embodiments are used without departing from the gist of the present invention. Of course, it can be done.

The present invention can be used in the driving device manufacturing industry and the like.

20 electric vehicle, 22a, 22b drive wheel, 24 differential gear, 26 drive shaft, 32 motor, 32a rotation position detection sensor, 32u, 32v current sensor, 34 inverter, 36 battery, 36a voltage sensor, 36b current sensor, 36c temperature sensor , 38 power line, 39 smoothing capacitor, 39a voltage sensor, 50 electronic control unit, 51 CPU, 52 ROM, 53 RAM, 60 ignition switch, 61 shift lever, 62 shift position sensor, 63 accelerator pedal, 64 accelerator pedal position sensor, 65 brake pedal, 66 brake pedal position sensor, 68 vehicle speed sensor, D11 to D16 diodes, T11 to T16 transistors.

Claims (1)

With the motor
An inverter that drives the motor by switching a plurality of switching elements,
A control device that switches and controls the inverter between pulse width modulation control and square wave control based on the torque command of the motor.
It is a drive device equipped with
When switching from the pulse width modulation control having a fixed modulation factor to the rectangular wave control, the control device
While gradually increasing the control modulation factor
When the difference between the control modulation factor and the pulse reduction modulation rate at which the number of pulses per electric cycle of the motor decreases is larger than a predetermined value, the voltage phase is based on the torque command and the control modulation factor. A command is set, and the inverter is controlled based on the voltage phase command and the control modulation factor.
When the difference between the control modulation factor and the pulse reduction modulation factor is equal to or less than the predetermined value, it is based on the reduction amount of the number of pulses at the pulse reduction modulation factor in addition to the torque command and the control modulation factor. The voltage phase command is set in consideration of the amount of change in the influence of the dead time, and the inverter is controlled based on the voltage phase command and the control modulation factor.
Drive device.

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