JP6686772B2 - Drive - Google Patents

Description

  The present invention relates to a drive device, and more particularly, to a drive device including a motor and an inverter.

  Conventionally, as a drive device of this type, a drive device including an electric motor and a power conversion device having an inverter circuit that drives the electric motor by switching a plurality of switching elements has been proposed (see, for example, Patent Document 1). In this drive device, the inverter circuit of the power conversion device is controlled as follows. First, the d-axis current command value and the q-axis current command value are set based on the torque command of the electric motor. Then, the d-axis voltage command value and the q-axis voltage command value are set based on the d-axis current command value and the q-axis current command value and the d-axis current value and the q-axis current value. Then, pulse signals of a plurality of switching elements are generated based on the modulation rate and phase angle of the voltage based on the d-axis voltage command value and the q-axis voltage command value, and the number of pulses in one electric cycle of the electric motor to generate a plurality of pulse signals. Performs switching of the switching element. At this time, a pulse signal is generated based on the modulation rate, the phase angle, and the number of pulses so that the power loss of the power conversion device and the electric motor is minimized, so that the loss of the entire drive system including the power conversion device and the electric motor. Is being reduced.

JP, 2013-162660, A

  In such a drive device, when switching a plurality of switching elements of the inverter circuit, an error voltage (insufficient supply voltage of the motor) occurs due to dead time. Then, as described above, when the pulse signal is generated based on the modulation rate, the phase angle, and the pulse pattern including the number of pulses to control the inverter circuit, when the pulse pattern is switched, the amplitude of the error voltage due to the dead time or The phase changes. However, in the case of controlling the inverter circuit in this way, since a method of compensating for the change in the error voltage at the time of switching the pulse pattern has not been established, at the time of switching the pulse pattern, the d-axis voltage command value and the q-axis The voltage command value may not be an appropriate value, and the controllability of the electric motor may be deteriorated.

  The drive device of the present invention is mainly intended to suppress a decrease in controllability of a motor.

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

The drive device of the present invention is
A motor,
An inverter that drives the motor by switching a plurality of switching elements,
The d-axis and q-axis current commands are set based on the motor torque command, and the d-axis and q-axis voltage commands are set based on the d-axis and q-axis current commands and the d-axis and q-axis currents. The PWM of the plurality of switching elements is set based on the modulation rate and voltage phase of the voltage set based on the voltage commands of the d-axis and the q-axis, and a pulse pattern including the number of pulses of a predetermined cycle of the electrical angle of the motor. A control device that generates a signal to switch the plurality of switching elements,
A drive device comprising:
The control device, when switching the pulse pattern,
The amplitude of the error voltage due to the dead time at the time of switching the plurality of switching elements before and after the switching of the pulse pattern, the current phase based on the current command of the d-axis and the q-axis, and the phase of the error voltage. And the phase difference of
Setting voltage correction values for the d-axis and the q-axis based on the amplitude and the phase difference before and after switching the pulse pattern,
The d-axis and q-axis base voltage commands based on the d-axis and q-axis current commands and the d-axis and q-axis current commands are corrected by using the d-axis and q-axis voltage correction values to correct the d-axis. Axis, q axis voltage command,
That is the summary.

  In the drive device of the present invention, when the pulse pattern is switched, the voltage commands for the d-axis and the q-axis are set as follows. First, the amplitude of the error voltage due to the dead time during the switching of the plurality of switching elements before and after the switching of the pulse pattern, and the position of the current phase based on the current command of the d-axis and the q-axis and the phase of the error voltage. The phase difference and are calculated respectively. Subsequently, the voltage correction values for the d-axis and the q-axis are set based on the amplitude and phase difference before and after switching the pulse pattern. Then, the d-axis and q-axis current commands and the d-axis and q-axis base voltage commands based on the d-axis and q-axis currents are corrected using the d-axis and q-axis voltage correction values, and the d-axis, Set the q-axis voltage command. That is, the d-axis and the q-axis based on the amplitude of the error voltage due to the dead time before and after the switching of the pulse pattern and the phase difference between the current phase before and after the switching of the pulse pattern and the phase of the error voltage due to the dead time, respectively. That is, the d-axis and q-axis base voltage commands are corrected using the voltage correction value of 1 to set the d-axis and q-axis voltage commands. This makes it possible to more appropriately compensate for the change in the error voltage due to the dead time before and after the switching of the pulse pattern, and to set the d-axis and q-axis voltage commands to more appropriate values. As a result, it is possible to prevent the controllability of the motor from deteriorating when the pulse pattern is switched. When the pulse pattern is not switched, the d-axis and q-axis base voltage commands may be set as the d-axis and q-axis voltage commands.

  In such a driving device of the present invention, the pulse pattern includes a pulse type in addition to the number of pulses, and the pulse type includes a type that generates the PWM signal so as to reduce iron loss of the motor and a harmonic. And a type of generating the PWM signal so as to reduce the frequency. In this case, when the number of pulses or the pulse type is switched, the change in the error voltage due to the dead time before and after the switching can be more appropriately compensated, and the d-axis and q-axis voltage commands can be set to more appropriate values. .

It is a block diagram which shows the outline of a structure of the electric vehicle 20 carrying the drive device as one Example of this invention. 5 is a flowchart showing an example of a second PWM signal generation routine executed by the electronic control unit 50 of the embodiment. It is explanatory drawing which shows an example of the PWM signal of the U-phase upper arm (transistor T11) of the motor 32. It is explanatory drawing which shows an example of a voltage correction value setting process. FIG. 6 is an explanatory diagram showing an example of a relationship between a previous pulse pattern (previous PP), a previous phase difference (previous Δθiv), and a phase difference Δθold before switching the pulse pattern PP.

  Next, modes for carrying out the present invention will be described using 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. The electric vehicle 20 of the embodiment includes a motor 32, an inverter 34, a battery 36, a boost converter 40, and an electronic control unit 50, as illustrated.

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

  The inverter 34 is connected to the motor 32 and also connected to the boost converter 40 via the high-voltage side power line 42. The inverter 34 has six transistors T11 to T16 and six diodes D11 to D16. Each of the transistors T11 to T16 is arranged in pairs so as to be on the source side and the sink side with respect to the positive bus and the negative bus of the high voltage side power line 42. The six diodes D11 to D16 are respectively connected in parallel to the transistors T11 to T16 in opposite directions. Each of the three-phase coils (U-phase, V-phase, W-phase) of the motor 32 is connected to each of the connection points between the paired transistors of 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 pair of transistors T11 to T16, so that a rotating magnetic field is formed in the three-phase coil and the motor is 32 is rotationally driven. Hereinafter, the transistors T11 to T13 may be referred to as "upper arm", and the transistors T14 to T16 may be referred to as "lower arm". A smoothing capacitor 46 is attached to the positive electrode bus and the negative electrode bus of the high voltage side power line 42.

  The battery 36 is configured as, for example, a lithium-ion secondary battery or a nickel-hydrogen secondary battery, and is connected to the boost converter 40 via the low-voltage power line 44. A smoothing capacitor 48 is attached to the positive electrode bus and the negative electrode bus of the low-voltage power line 44.

  The boost converter 40 is connected to the high voltage side power line 42 and the low voltage side power line 44. This boost converter 40 has two transistors T31 and T32, two diodes D31 and D32, and a reactor L. The transistor T31 is connected to the positive bus of the high voltage side power line 42. The transistor T32 is connected to the transistor T31 and the negative voltage bus lines of the high voltage side power line 42 and the low voltage side power line 44. The two diodes D31 and D32 are connected in parallel to the transistors T31 and T32 in opposite directions, respectively. The reactor L is connected to a connection point between the transistors T31 and T32 and a positive bus of the low voltage side power line 44. The boost converter 40 supplies the power of the low-voltage side power line 44 to the high-voltage side power line 42 by boosting the voltage by adjusting the ON time ratio of the transistors T31 and T32 by the electronic control unit 50. Alternatively, the power of the high-voltage side power line 42 is supplied to the low-voltage side power line 44 with a voltage drop.

  The electronic control unit 50 is configured as a microprocessor centered on a CPU 52, and includes a CPU 54, a ROM 54 for storing a processing program, a RAM 56 for temporarily storing data, and an input / output port.

  Signals from various sensors are input to the electronic control unit 50 via input ports. As the signal input to the electronic control unit 50, for example, the rotational position θm from a rotational position detection sensor (for example, a resolver) 32a that detects the rotational position of the rotor of the motor 32, and the current flowing in each phase of the motor 32 are detected. The phase currents Iu and Iv from the current sensors 32u and 32v that operate are listed. Moreover, the voltage VB from the voltage sensor 36a attached between the terminals of the battery 36 and the current IB from the current sensor 36b attached to the output terminal of the battery 36 can also be mentioned. Further, the voltage VH of the capacitor 46 (high voltage side power line 42) from the voltage sensor 46a attached between the terminals of the capacitor 46, and the capacitor 48 (low voltage side from the voltage sensor 48a attached between the terminals of the capacitor 48). The voltage VL of the power line 44) can also be mentioned. In addition, an ignition signal from the ignition switch 60, a shift position SP from a shift position sensor 62 that detects the operation position of the shift lever 61, and an accelerator opening Acc from an 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 amount of depression of the brake pedal 65 can also be mentioned. Moreover, the vehicle speed VS from the vehicle speed sensor 68 can also be mentioned.

  Various control signals are output from the electronic control unit 50 via the output ports. Examples of signals output from the electronic control unit 50 include switching control signals to the transistors T11 to T16 of the inverter 34 and switching control signals to the transistors T31 and T32 of the boost converter 40.

  The electronic control unit 50 calculates the electrical angle θe, the angular velocity ωm, 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 charge ratio SOC of the battery 36 based on the integrated value of the current IB of the battery 36 from the current sensor 36b. Here, the charge ratio SOC is the ratio of the capacity of the electric power that can be discharged from the battery 36 to the total capacity of the battery 36.

  In the thus configured electric vehicle 20 of the embodiment, the electronic control unit 50 performs the following traveling control. In the traveling control, the required torque Td * required for the drive shaft 26 is set based on the accelerator opening Acc and the vehicle speed VS, and the set required torque Td * is set as the torque command Tm * of the motor 32. Performs switching control of the transistors T11 to T16 of the inverter 34 so that is driven by the torque command Tm *. Further, the target voltage VH * of the high voltage side power line 42 is set so that the motor 32 can be driven by the torque command Tm *, and the boost converter 40 is set so that the voltage VH of the high voltage side power line 42 becomes the target voltage VH *. The switching control of the transistors T31 and T32 is performed.

  Here, the control of the inverter 34 will be described. In the embodiment, as the control of the inverter 34, any one of sine wave PWM (pulse width modulation) control, overmodulation PWM control, and rectangular wave control is executed. The sine wave PWM control is control for controlling the inverter 34 so that a pseudo three-phase AC voltage is applied (supplied) to the motor 32, and the overmodulation PWM control is for applying the overmodulation voltage to the motor 32. Thus, the rectangular wave control is control for controlling the inverter 34 so that the rectangular wave voltage is applied to the motor 32. When performing the sine wave PWM control, when the pulse width modulation voltage based on the sine wave voltage is set to a pseudo three-phase AC voltage, the modulation rate Rm becomes a value of 0 to approximately 0.61, and the sine wave voltage has a 3n order ( For example, when the pulse width modulation voltage based on the superimposed voltage obtained by superimposing the (third) harmonic voltage is a pseudo three-phase AC voltage, the modulation rate Rm is 0 to approximately 0.71. The modulation rate Rm is the ratio of the effective value of the output voltage (the voltage applied to the motor 32) to the input voltage of the inverter 34 (the voltage VH of the high voltage side power line 42). In the embodiment, in order to increase the area of the modulation rate Rm in which the sine wave PWM control can be executed, the pulse width modulation voltage based on the post-superimposition voltage is set to a pseudo three-phase AC voltage. Further, when the rectangular wave control is executed, the modulation rate Rm is about 0.78. In the embodiment, based on these, any one of the sine wave PWM control, the overmodulation PWM control, and the rectangular wave control is executed based on the modulation rate Rm. The sine wave PWM control will be described below. Since the overmodulation PWM control and the rectangular wave control do not form the core of the present invention, detailed description thereof will be omitted.

  As the sine wave PWM control, in the embodiment, the first PWM control or the second PWM control is executed. In the first PWM control, the voltage commands Vu *, Vv *, Vw * of each phase of the motor 32 are compared with the carrier wave voltage (triangular wave voltage) to generate the first PWM signal of the transistors T11 to T16 to switch the transistors T11 to T16. Is a control for performing. In the second PWM control, the second PWM signals of the transistors T11 to T16 are generated based on the voltage modulation rate Rm, the voltage phase θv, and the pulse pattern PP having a predetermined cycle (for example, a half cycle or one cycle of the electrical angle θe of the motor 32). This control is for generating and switching the transistors T11 to T16. Here, the pulse pattern PP is a combination of the pulse type PT and the pulse number Np in the PWM control. In the embodiment, as the pulse type PT, a type PTa that generates a PWM signal so as to reduce (for example, minimize) the iron loss of the motor 32 and harmonics of voltage and current (particularly, lower harmonics) are reduced. The type PTb that generates a PWM signal so as to (for example, minimize) is used. As for the pulse pattern PP, in the embodiment, the relationship between the target operating point (the rotation speed Nm and the torque command Tm *) of the motor 32 and the pulse pattern PP is predetermined and stored in the ROM 54 as a map, and the target operation of the motor 32 is stored. Given a point, it was applied to this map to set the pulse pattern PP.

  When the first PWM control is executed, the generation period of the PWM signal can be shortened as compared with the case where the second PWM control is executed. Therefore, the responsiveness of the motor 32 (the operating point when the target operating point changes) Followability) can be improved. Further, when the second PWM control is executed, the second PWM signal is generated so as to reduce (for example, minimize) the iron loss of the motor 32, or harmonics of voltage or current (in particular, rotation 6th order or rotation of the motor 32). The iron loss of the motor 32 is reduced as compared with the case where the first PWM control is executed by generating the second PWM signal so as to reduce (for example, minimize) the low-order harmonics such as the 12th order. Can be performed or harmonics can be reduced.

  Next, the operation of the electric vehicle 20 of the embodiment thus configured, particularly the operation when generating the second PWM signal used for the second PWM control will be described. FIG. 2 is a flowchart showing an example of a second PWM signal generation routine executed by the electronic control unit 50 of the embodiment. This routine is repeatedly executed.

  When the second PWM signal generation routine is executed, the CPU 52 of the electronic control unit 50 first causes the phase currents Iu and Iv of the motor 32, the electrical angle θe, the rotation speed Nm, the torque command Tm *, and the high voltage side power line 42. Data such as the voltage VH, the pulse pattern PP and the switching frequency fs are input (step S100). Here, as the phase currents Iu and Iv of the motor 32, the values detected by the current sensors 32u and 32v are input. The electrical angle θe and the rotation speed Nm of the motor 32 are input as values calculated based on the rotational position θm of the rotor of the motor 32 detected by the rotational position detection sensor 32a. As the torque command Tm * of the motor 32, the value set by the drive control described above is input. The voltage VH of the high voltage side power line 42 is the one detected by the voltage sensor 46a. As the pulse pattern PP (pulse type PT and pulse number Np), the one set based on the target operating point of the motor 32 as described above is input. As the switching frequency fs, the inverse number (Np / Te) of a value obtained by dividing the time Te of one cycle of the electrical angle θe of the motor 32 by the pulse number Np is input. The time Te can be calculated based on the rotation speed Nm of the motor 32 and the number of pole pairs of the motor 32.

  When the data is thus input, the d-axis and q-axis current commands Id * and Iq * are set based on the torque command Tm * of the motor 32 (step S110). Subsequently, assuming that the sum of the currents flowing in the respective phases (U phase, V phase, W phase) of the motor 32 is 0, the electric current θe of the motor 32 is used to calculate the phase current Iu of the U phase and the V phase. Coordinate conversion (3-phase-2 phase conversion) of Iv into d-axis and q-axis currents Id and Iq (step S120). Then, the feedback term based on the difference ΔId, ΔIq between the d-axis / q-axis current commands Id *, Iq * and the d-axis / q-axis currents Id, Iq and the d-axis and q-axis interfere with each other. The base voltage commands Vdtmp and Vqtmp as temporary values of the d-axis and q-axis voltage commands Vd * and Vq * are set by the sum of the feedforward term for canceling the term and the voltage commands Vdtmp and Vqtmp (step S130).

  Next, it is determined whether or not the pulse pattern PP (pulse type PT and pulse number Np) has been switched (step S140). This processing can be performed by comparing the pulse pattern input at this time of execution of this routine (current PP) with the pulse pattern input at the time of previous execution (previous PP).

  When it is determined in step S140 that the pulse pattern PP has not been switched, the voltage correction values ΔVd and ΔVq for correcting the d-axis and q-axis base voltage commands Vdtmp and Vqtmp are both set to the value 0 (step S150). . Then, the voltage correction values ΔVd and ΔVq are added to the d-axis and q-axis base voltage commands Vdtmp and Vqtmp to set the d-axis and q-axis voltage commands Vd * and Vq * (step S170).

  When the d-axis and q-axis voltage commands Vd * and Vq * are set in this way, the voltage modulation rate Rm and the voltage phase θv are set using the set d-axis and q-axis voltage commands Vd * and Vq * (step S180). Here, the modulation factor Rm is the voltage command absolute value Vdq calculated as the square root of the sum of the square of the d-axis voltage command Vd * and the square of the q-axis voltage command Vq *, and the voltage of the high-voltage side power line 42. It can be obtained by dividing by VH. The voltage phase θv can be obtained as an angle with respect to the q axis of the voltage vector having the voltage commands Vd * and Vq * on the d axis and the q axis as components.

  Next, the current phase θi is set using the d-axis and q-axis current commands Id * and Iq * (step S190), and the phase difference Δθiv (= θi−θv) between the current phase θi and the voltage phase θv is calculated. (Step S200). Here, the current phase θi can be obtained as an angle with respect to the q axis of the current vector having the d-axis and q-axis current commands Id * and Iq * as components. The phase difference Δθiv is used in the voltage correction value setting process described later.

  Subsequently, the switching angle θs and the switching pattern V are set based on the pulse pattern PP, the modulation rate Rm, and the voltage phase θv (step S210), and the second PWM signal is set based on the set switching angle θs and the switching pattern V. Is generated (step S220), and this routine ends.

  Here, the switching angle θs is an angle for switching the phase voltage of each phase of the motor 32 (ON / OFF of the transistor of the corresponding phase among the transistors T11 to T16, for example, ON / OFF of the transistors T11 and T14 for the U phase).

Further, the switching pattern V is a pattern indicating a combination of ON / OFF of the transistors T11 to T13, and patterns V0 to V7 are used. It should be noted that the use of the on / off combination of the transistors T11 to T13 instead of the on / off combination of the transistors T11 to T16 does not normally turn on the corresponding upper arm and lower arm of the transistors T11 to T16 at the same time. This is because the combination of turning on and off the transistors T14 to T16 may be omitted. The patterns V0 to V7 are as follows.
Pattern V0: All of the transistors T11 to T13 are off Pattern V1: Transistors T11 and T12 are off and transistor T13 is on Pattern V2: Transistors T11 and T13 are off and transistor T12 is on Pattern V3: Transistor T11 is off and transistor T12, T13 is on Pattern V4: Transistor T11 is on and transistors T12 and T13 are off Pattern V5: Transistors T11 and T13 are on and transistor T12 is off Pattern V6: Transistors T11 and T12 are on and transistor T13 is off Pattern V7: Transistor T11 ~ T13 is all on

  Further, an example of the PWM signal of the upper arm (transistor T11) of the U phase of the motor 32 is shown in FIG. When the PWM signal is generated in this manner, the transistors T11 to T16 of the inverter 34 are switched using the generated PWM signal. That is, the transistors T11 to T16 are switched so that the switching angle θs of the motor 32 results in the switching pattern V corresponding to the switching angle θs. By such control, the iron loss of the motor 32 and the harmonics of the voltage and the current can be reduced according to the pulse pattern PP including the pulse type PT (type PTa or type PTb) and the pulse number Np. .

  When it is determined in step S140 that the pulse pattern PP has been switched, the voltage correction values ΔVd and ΔVq of the d-axis and the q-axis are set by the voltage correction value setting process of FIG. 4 (step S160), and the processes of steps S170 to S220 are performed. The routine is executed to end this routine.

  Next, the voltage correction value setting process of FIG. 4 will be described. In the voltage correction value setting process, the CPU 52 of the electronic control unit 50 first performs a pulse based on the pulse pattern (hereinafter simply referred to as “previous”) when the second PWM signal generation routine was executed last time (hereinafter simply referred to as “previous PP”). Before switching the pattern PP, the basic amplitude Vpoltmp of the error voltage (insufficient supply voltage of the motor 32) due to dead time at the time of switching the transistors T11 to T16 of the inverter 34 is set (step S300). Here, in the embodiment, the basic amplitude Vpoltmp of the error voltage due to the dead time before the switching of the pulse pattern PP is set to the previous pulse pattern according to the predetermined relationship between the pulse pattern PP and the basic amplitude Voldtmp of the error voltage due to the dead time. (Previous PP) is applied and set. Note that the fundamental amplitude Vpoldtmp in this relationship uses the amplitude of the fundamental wave (first-order component of the electrical angle θe of the motor 32) obtained by frequency-analyzing the waveform of the error voltage for the pulse pattern PP.

  When the basic amplitude Vpoltmp of the error voltage due to the dead time before the switching of the pulse pattern PP is set in this way, as shown in the equation (1), the basic amplitude Vpoltmp and the voltage of the previous high voltage side power line 42 (previous VH). And the previous switching frequency (previous fs) are set as the amplitude Vpold of the error voltage due to the dead time before switching the pulse pattern PP (step S310).

  Vpold = Vpoldtmp-previous VH-previous fs (1)

  Then, based on the previous pulse pattern (previous PP) and the phase difference (previous Δθiv) between the previous current phase (previous θi) and the previous voltage phase (previous θv), before switching the pulse pattern PP. A phase difference Δθold between the current phase and the phase of the error voltage due to the dead time is set (step S320). Here, the phase difference Δθold before switching the pulse pattern PP corresponds to the current phase before switching the pulse pattern PP with respect to the phase of the error voltage due to the dead time before switching the pulse pattern PP, and in the embodiment, the previous pulse. In the predetermined relationship between the pattern (previous PP), the previous phase difference (previous Δθiv), and the phase difference Δθold before switching the pulse pattern PP, the previous pulse pattern (previous PP) and the previous phase difference (previous Δθiv) And are applied and set. FIG. 5 shows an example of the relationship between the previous pulse pattern (previous PP), the previous phase difference (previous Δθiv), and the phase difference Δθold before switching the pulse pattern PP. In the example of FIG. 5, the previous pulse pattern (previous PP) is different depending on which of the patterns A to D, and when the previous phase difference (previous Δθiv) is large, it is larger than when it is small. The phase difference Δθold is set so that

  Then, before the switching of the pulse pattern PP, based on the amplitude Vpold of the error voltage due to the dead time before the switching of the pulse pattern PP and the phase difference Δθold between the current vector before the switching of the pulse pattern PP and the error voltage due to the dead time. The d-axis and q-axis components ΔVdold and ΔVqold of the error voltage due to the dead time are set (step S330).

  Next, the basic amplitude of the error voltage due to the dead time after the switching of the pulse pattern PP is based on the pulse pattern (hereinafter simply referred to as “this time”) when the second PWM signal generation routine is executed this time. Vpnewmp is set (step S340). Here, in the embodiment, the basic amplitude Vpnewmp of the error voltage due to the dead time after switching the pulse pattern PP is "basic amplitude" in the predetermined relationship between the above-mentioned pulse pattern PP and the basic amplitude Verrortmp of the error voltage due to the dead time. It is assumed that the pulse pattern of this time (PP of this time) is applied to the one in which “Voldtmp” is replaced with “basic amplitude Vpnewtmp” to set.

  When the basic amplitude Vpnewwtmp of the error voltage due to the dead time after the switching of the pulse pattern PP is set in this way, this basic amplitude Vpnewmp and the voltage of the current high voltage side power line 42 (currently VH) are obtained as shown in Expression (2). Then, the product of the current switching frequency (current fs) is set as the amplitude Vpnew of the error voltage due to the dead time after switching the pulse pattern PP (step S350).

  Vpnew = Vpnewtmp ・ This time VH ・ This time fs (2)

  Next, based on the current pulse pattern (current PP) and the phase difference (previous Δθiv) between the previous current phase (previous θi) and the previous voltage phase (previous θv), the pulse pattern PP after switching is changed. The phase difference Δθnew between the current vector and the error voltage due to the dead time is set (estimated) (step S360). Here, the phase difference Δθnew after switching the pulse pattern PP corresponds to the current phase after switching the pulse pattern PP with respect to the phase of the error voltage due to the dead time after switching the pulse pattern PP. Of the previous pulse pattern (previous PP) and the previous phase difference (previous Δθiv) of the pulse pattern (previous PP) and the phase difference Δθold before switching of the pulse pattern PP (see FIG. 5) and This pulse pattern (current PP) is obtained by replacing the “phase difference Δθold before switching the pulse pattern PP” with the “current pulse pattern (current PP)” and the “phase difference Δθnew after switching the pulse pattern PP”. And the previous phase difference (previous Δθiv) are applied and set. It should be noted that when setting the phase difference Δθnew after switching the pulse pattern PP, it is considered that the current phase difference (current Δθiv) should be used instead of the previous phase difference (previous Δθiv). . However, as described above, since the voltage commands Vd * and Vq * are set using the d-axis and q-axis voltage correction values ΔVd and ΔVq, the voltage phase θv and the phase difference Δθiv are set. In the processing, the current phase difference (current Δθiv) cannot be used. Therefore, in the embodiment, the previous phase difference (previous Δθiv) is used instead of the current phase difference (present Δθiv).

  After the switching of the pulse pattern PP, the amplitude Vpnew of the error voltage due to the dead time after the switching of the pulse pattern PP and the phase difference Δθnew between the current vector after the switching of the pulse pattern PP and the error voltage due to the dead time are switched. The d-axis and q-axis components ΔVdnew and ΔVqnew of the error voltage due to the dead time are set (step S370).

  When the d-axis and q-axis components ΔVold and ΔVqold of the error voltage due to the dead time before switching the pulse pattern PP and the d-axis and q-axis components ΔVdnew and ΔVqnew of the error voltage due to the dead time after switching the pulse pattern PP are set. As shown in Equations (3) and (4), the d-axis and q-axis components ΔVdold and ΔVqold are subtracted from the d-axis and q-axis components ΔVdnew and ΔVqnew to obtain the d-axis and q-axis voltage correction values ΔVd, ΔVq is set (step S380), and this routine ends. When the d-axis and q-axis voltage correction values ΔVd and ΔVq are set in this manner, as described above, in the second PWM signal generation routine of FIG. 2, the d-axis and q-axis base voltage commands Vdtmp and Vqtmp are set to the voltage correction values ΔVd, ΔVq is added to set the d-axis and q-axis voltage commands Vd * and Vq * (step S170), and the second PWM signal is generated using the d-axis and q-axis voltage commands Vd * and Vq * (step S170). S180-S220).

ΔVd = ΔVdold-ΔVdnew (3)
ΔVq = ΔVqold-ΔVqnew (4)

  When the first PWM control is executed, the error voltage due to the dead time can be represented by the average value of one cycle of the electrical angle θe of the motor 32 (square wave approximation is possible), and the phase of the error voltage due to the current phase and the dead time. Based on the fact that the phase difference between and is π, the method of calculating the error voltage due to the dead time is known based on the frequency of the carrier voltage, the dead time, and the voltage VH of the high voltage side power line 42. There is. Therefore, when the frequency of the carrier voltage changes, this method can be used to compensate for the error voltage (voltage shortage) due to dead time. However, when the second PWM control is performed, the degree of freedom of the switching angle θs and the switching pattern V is higher than that when the first PWM control is performed, and therefore the error voltage due to the dead time is set to 1 of the electrical angle θe of the motor 32. It cannot be represented by the average value of the cycle, and the phase difference between the current phase and the phase of the error voltage due to the dead time does not always become π. Therefore, with the same method as the first PWM control, there is a possibility that the change in the error voltage due to the dead time before and after the switching of the pulse pattern PP cannot be appropriately compensated. Further, another method for compensating for the change in the error voltage due to the dead time before and after the switching of the pulse pattern PP has not been established. To solve such a problem, in the embodiment, the amplitudes Vpold and Vpnew of the error voltages due to the dead times before and after the switching of the pulse pattern PP, and the phase of the current vectors before and after the switching of the pulse pattern PP and the error voltage due to the dead time. And the phase differences Δθold and Δθnew with respect to the d-axis and q-axis voltage correction values ΔVd and ΔVq are used to correct the d-axis and q-axis base voltage commands Vdtmp and Vqtmp to correct the d-axis and q-axis voltage commands. Set Vd * and Vq *. This makes it possible to more appropriately compensate for the change in the error voltage due to the dead time before and after the switching of the pulse pattern PP, and to set the d-axis and q-axis voltage commands Vd * and Vq * to more appropriate values. . As a result, it is possible to prevent the controllability of the motor 32 from decreasing when the pulse pattern PP is switched.

  In the drive device mounted on the electric vehicle 20 of the embodiment described above, when switching the pulse pattern PP, the d-axis and q-axis voltage commands Vd * and Vq * are set as follows. First, before the switching of the pulse pattern PP, the error voltage amplitude Vpold due to the dead time and the phase difference Δθold between the current vector and the error voltage due to the dead time are based on the d-axis and the q-axis of the error voltage due to the dead time. The components ΔVold and ΔVqold are set. Then, after the switching of the pulse pattern PP, the d-axis and q-axis of the error voltage due to dead time are based on the amplitude Vpnew of the error voltage due to dead time and the phase difference Δθnew between the current vector and the error voltage due to dead time. The components ΔVdnew and ΔVqnew of are set. Then, the d-axis and q-axis components ΔVdold and ΔVqold are subtracted from the d-axis and q-axis components ΔVdnew and ΔVqnew to set the d-axis and q-axis voltage correction values ΔVd and ΔVq. The d-axis and q-axis voltage correction values ΔVd and ΔVq are added to the d-axis and q-axis base voltage commands Vdtmp and Vqtmp to set the d-axis and q-axis voltage commands Vd * and Vq *. By setting the d-axis and q-axis voltage commands Vd * and Vq * in this way, it is possible to more appropriately compensate for the change in the error voltage due to the dead time before and after the switching of the pulse pattern PP. The axis voltage commands Vd * and Vq * can be set to more appropriate values. As a result, it is possible to prevent the controllability of the motor 32 from decreasing when the pulse pattern PP is switched.

  In the drive device mounted on the electric vehicle 20 of the embodiment, when the pulse pattern PP is switched, the voltage correction values ΔVd and ΔVq of the d-axis and the q-axis are set by the voltage correction value setting process of FIG. The q-axis voltage correction values ΔVd and ΔVq are set in addition to the d-axis and q-axis base voltage commands Vdtmp and Vqtmp, and the d-axis and q-axis voltage commands Vd * and Vq * are set. However, even when switching between the first PWM control and the second PWM control, the voltage correction values ΔVd and ΔVq for the d-axis and the q-axis are set by the voltage correction value setting process of FIG. 4, and the voltage correction values for the d-axis and the q-axis are set. ΔVd and ΔVq may be added to the d-axis and q-axis base voltage commands Vdtmp and Vqtmp to set the d-axis and q-axis voltage commands Vd * and Vq *.

  In the drive device mounted on the electric vehicle 20 of the embodiment, the pulse type PT of the pulse pattern PP used when generating the second PWM signal is the type PTa that generates the PWM signal so as to reduce the iron loss of the motor 32. , A type PTb that generates a PWM signal so as to reduce harmonics of voltage and current, and a type PTb. However, as the pulse type PT, three or more pulse types PT may be used. In this case, for example, a type that generates a PWM signal to reduce the iron loss of the motor 32, a type that generates a PWM signal to reduce the copper loss of the motor 32, and a PWM signal that reduces the torque ripple of the motor 32. To generate the PWM signal, to reduce the loss of the inverter 34, to generate the PWM signal to reduce the total loss of the motor 32 and the inverter 34, to reduce the harmonics of the voltage. A type that generates a PWM signal, a type that generates a PWM signal so as to reduce harmonics of current, or the like may be used.

  In the drive device mounted on the electric vehicle 20 of the embodiment, only one type may be used as the pulse type PT of the pulse pattern PP used when generating the PWM signal. In this case, the pulse pattern PP may be set according to only the pulse number Np.

  In the drive device mounted on the electric vehicle 20 of the embodiment, the boost converter 40 is provided between the inverter 34 and the battery 36, but the boost converter may not be provided.

  In the embodiment, the drive device mounted on the electric vehicle 20 is used. However, as long as it has a configuration of a drive device including a motor and an inverter, it may be a configuration of a drive device mounted on a vehicle other than an electric vehicle, for example, a hybrid vehicle or a fuel cell vehicle, and may be a mobile device such as a construction facility. The drive device may be configured to be installed in equipment that does not.

  Correspondence between the main elements of the embodiment 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 a “motor”, the inverter 34 corresponds to an “inverter”, and the electronic control unit 50 corresponds to a “control device”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the section of means for solving the problem. Since this is an example for specifically explaining the mode for carrying out the invention, it does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problem should be made based on the description in that column, and the embodiment is the invention of the invention described in the column of means for solving the problem. This is just a specific example.

  Although the embodiments for carrying out the present invention have been described above with reference to the embodiments, the present invention is not limited to these embodiments, and various embodiments are possible within the scope not departing from the gist of the present invention. Of course, it can be implemented.

  INDUSTRIAL APPLICABILITY The present invention can be used in the drive device manufacturing industry and the like.

  20 electric vehicle, 22a, 22b drive wheel, 24 differential gear, 26 drive shaft, 32 motor, 32a rotational position detection sensor, 32u, 32v, 36b current sensor, 34 inverter, 36 battery, 36a, 46a, 48a voltage sensor, 40 Boost converter, 42 high voltage side power line, 44 low voltage side power line, 46, 48 capacitor, 50 electronic control unit, 52 CPU, 54 ROM, 56 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, D31, D32 diode, L reactor, T11 to T 6, T31, T32 transistor.

Claims (1)

A motor,
An inverter that drives the motor by switching a plurality of switching elements,
The d-axis and q-axis current commands are set based on the motor torque command, and the d-axis and q-axis voltage commands are set based on the d-axis and q-axis current commands and the d-axis and q-axis currents. The PWM of the plurality of switching elements is set based on the modulation rate and voltage phase of the voltage set based on the voltage commands of the d-axis and the q-axis, and a pulse pattern including the number of pulses of a predetermined cycle of the electrical angle of the motor. A control device that generates a signal to switch the plurality of switching elements,
A drive device comprising:
The control device, when switching the pulse pattern,
The amplitude of the error voltage due to the dead time at the time of switching the plurality of switching elements before and after the switching of the pulse pattern, the current phase based on the current command of the d-axis and the q-axis, and the phase of the error voltage. And the phase difference of
Setting voltage correction values for the d-axis and the q-axis based on the amplitude and the phase difference before and after switching the pulse pattern,
The d-axis and q-axis base voltage commands based on the d-axis and q-axis current commands and the d-axis and q-axis current commands are corrected by using the d-axis and q-axis voltage correction values to correct the d-axis. Axis, q axis voltage command,
Drive.

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