JP2016208728A - Driver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress vibration or noises occurring when switching the control of an inverter from synchronous carrier PWM control system to asynchronous carrier PWM control system.SOLUTION: When switching from synchronous carrier PWM control system to asynchronous carrier PWM control system, the difference (frequency difference) ΔF between the carrier frequency Fc at that time and the carrier frequency Fcset of asynchronous carrier PWM control system is calculated (S170). When the frequency difference ΔF is equal to or larger than a threshold Fref, switching from the synchronous carrier PWM control system to asynchronous carrier PWM control system is prohibited and the synchronous carrier PWM control system is continued (S200), and after the frequency difference ΔF becomes less than the threshold Fref, switching is made from the synchronous carrier PWM control system to asynchronous carrier PWM control system (S210). Consequently, occurrence of vibration or noises can be suppressed at the time of switching.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a drive device, and more particularly to a drive device that controls an inverter that drives an electric motor by a plurality of control methods including a synchronous carrier PWM control method and an asynchronous carrier PWM control method.

  Conventionally, as this type of driving apparatus, an apparatus that controls an inverter that drives an electric motor by selectively switching between a synchronous carrier PWM control system and an asynchronous carrier PWM control system has been proposed (for example, see Patent Document 1). . Here, the synchronous carrier PWM control system is a control system that switches a plurality of switching elements of the inverter by a pulse width modulation control system using a carrier frequency that is changed in synchronization with the rotation speed of the electric motor. The asynchronous carrier PWM control system is a control system that switches a plurality of switching elements of the inverter by a pulse width modulation control system using a predetermined carrier frequency, and is not synchronized with the rotation speed of the motor. In this driving device, the synchronous carrier PWM method is selected when the phase difference between the actual phase of the phase voltage command and the target phase when the carrier wave becomes maximum is smaller than the threshold value, and the phase difference is smaller than the threshold value. If it is larger, the fixed carrier PWM method is selected.

JP 2011-72103 A

  However, in the above drive device, when switching the inverter control from the synchronous carrier PWM control method to the asynchronous carrier PWM control method, if the difference between the carrier frequency before switching the control method and the carrier frequency after switching is large, vibration or Abnormal noise may occur. Such vibration and abnormal noise give a sense of incongruity to an occupant or the like when the drive device is mounted on a vehicle or the like.

  The drive device of the present invention is mainly intended to suppress vibration and abnormal noise that may occur when switching the inverter control from the synchronous carrier PWM control method to the asynchronous carrier PWM control method.

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

The drive device of the present invention is
Switching a plurality of switching elements of the inverter by a pulse width modulation control method using an electric motor, an inverter having a plurality of switching elements and driving the motor, and a carrier frequency changed in synchronization with the rotation speed of the motor The electric motor according to any one of a plurality of control methods including a synchronous carrier PWM control method that performs switching and a asynchronous carrier PWM control method that switches a plurality of switching elements of the inverter by a pulse width modulation control method using a predetermined carrier frequency. And a control means for controlling the inverter so as to be driven,
The control means, when switching the control of the inverter from the synchronous carrier PWM control method to the asynchronous carrier PWM control method, a frequency difference between a carrier frequency by the synchronous carrier PWM control method and a carrier frequency by the asynchronous carrier PWM control method Is switched from the synchronous carrier PWM control method to the asynchronous carrier PWM control method to continue the synchronous carrier PWM control method after the frequency difference reaches less than the predetermined value. Means for switching from the synchronous carrier PWM control method to the asynchronous carrier PWM control method.
It is characterized by that.

  In the drive device of the present invention, when switching the control of the inverter that drives the motor from the synchronous carrier PWM control method to the asynchronous carrier PWM control method, the carrier frequency by the synchronous carrier PWM control method and the carrier frequency by the asynchronous carrier PWM control method are When the frequency difference is greater than or equal to a predetermined value, the switching from the synchronous carrier PWM control method to the asynchronous carrier PWM control method is prohibited and the synchronous carrier PWM control method is continued, and then the synchronous carrier after the frequency difference reaches less than the predetermined value. The PWM control method is switched to the asynchronous carrier PWM control method. As a result, it is possible to suppress vibrations and abnormal noise that may occur when switching from the synchronous carrier PWM control method to the asynchronous carrier PWM control method when the frequency difference is large. Here, the electric motor includes not only a motor that functions as a motor but also a motor that functions as a generator.

It is a block diagram which shows the outline of a structure of the hybrid vehicle 20 provided with the drive device as one Example of this invention. It is a block diagram which shows the outline of a structure of the electric drive system containing motor MG1, MG2. 4 is a flowchart showing an example of an inverter control system switching routine executed by a motor ECU 40. It is explanatory drawing which shows an example of the relationship between the carrier frequency of an asynchronous carrier PWM control system and a synchronous carrier PWM control system, and the rotation speed Nm of a motor.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 including a drive device as an embodiment of the present invention, and FIG. 2 is a configuration showing an outline of the configuration of an electric drive system including motors MG1 and MG2. FIG. As shown in FIG. 1, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, and a hybrid electronic control unit (hereinafter referred to as HVECU). 70.

  The engine 22 is configured as an internal combustion engine that outputs power using gasoline or light oil as a fuel. Operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as engine ECU) 24.

  Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The engine ECU 24 receives signals from various sensors necessary for controlling the operation of the engine 22, for example, a crank angle θcr from a crank position sensor that detects the rotational position of the crankshaft 26, and the like via an input port. Yes. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 through an output port. The engine ECU 24 is connected to the HVECU 70 via a communication port, controls the operation of the engine 22 by a control signal from the HVECU 70, and outputs data related to the operating state of the engine 22 to the HVECU 70 as necessary. The engine ECU 24 calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22, based on the crank angle θcr from the crank position sensor.

  The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The sun gear, the ring gear, and the carrier of the planetary gear 30 are connected to the rotor of the motor MG1, the drive shaft 36 coupled to the drive wheels 38a and 38b via the differential gear 37, and the crankshaft 26 of the engine 22, respectively.

  The motor MG1 is configured as a synchronous generator motor having a rotor in which a permanent magnet is embedded and a stator in which a three-phase coil is wound, and the rotor is connected to the sun gear of the planetary gear 30 as described above. Yes. The motor MG2 is configured as a synchronous generator motor similar to the motor MG1, and the rotor is connected to the drive shaft 36.

  As shown in FIG. 2, the inverter 41 includes six transistors T11 to T16 and six diodes D11 to D16 connected in parallel to the transistors T11 to T16 in the reverse direction. 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 and negative buses of the power line 54 from the battery 50, respectively. In the transistors T11 to T16, each of the three-phase coils (U-phase, V-phase, W-phase) of the motor MG1 is connected to each connection point between the paired transistors. Therefore, when a voltage is applied to the inverter 41, the motor electronic control unit (hereinafter referred to as a motor ECU) 40 adjusts the ratio of the on-time of the paired transistors T11 to T16, so that three-phase A rotating magnetic field is formed in the coil, and the motor MG1 is driven to rotate. Similarly to the inverter 41, the inverter 42 includes six transistors T21 to T26 and six diodes D21 to D26. When the voltage is applied to the inverter 42, the motor ECU 40 adjusts the ratio of the on-time of the paired transistors T21 to T26, whereby a rotating magnetic field is formed in the three-phase coil, and the motor MG2 is Driven by rotation.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . As shown in FIG. 1, the motor ECU 40 receives signals from various sensors necessary for driving and controlling the motors MG1 and MG2, for example, a rotational position detection sensor for detecting the rotational position of the rotor of the motors MG1 and MG2. Rotation position θm1, θm2, motor MG1, MG2 phase current from the current sensor that detects the current flowing in each phase, capacitor voltage (not shown) of the voltage sensor attached between the terminals of the capacitor 46 Voltage) VB or the like is input via the input port. Further, the motor ECU 40 outputs switching control signals to the transistors T11 to T16 and T21 to T26 of the inverters 41 and 42 via the output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 controls driving of the motors MG1 and MG2 and the boost converter according to a control signal from the HVECU 70, and transmits data related to the driving state of the motors MG1 and MG2 to the HVECU 70 as necessary. Output. The motor ECU 40 calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotational positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from the rotational position detection sensor.

  The battery 50 is configured as a lithium ion secondary battery or nickel hydride secondary battery of 200V or 250V, for example, and is connected to the power line 54 as described above. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52.

  Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The battery ECU 52 includes signals necessary for managing the battery 50, for example, a battery voltage Vb from a voltage sensor (not shown) installed between the terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The battery current Ib from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor (not shown) attached to the battery 50, and the like are input via the input port. The battery ECU 52 is connected to the HVECU 70 via a communication port, and outputs data relating to the state of the battery 50 to the HVECU 70 as necessary. In order to manage the battery 50, the battery ECU 52 determines a storage ratio SOC, which is a ratio of the capacity of electric power that can be discharged from the battery 50 at that time, based on the integrated value of the battery current Ib detected by the current sensor. The input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 50, are calculated based on the calculated power storage ratio SOC and the battery temperature Tb detected by the temperature sensor. .

  Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. Various signals are input to the HVECU 70 through an input port. Examples of signals input to the HVECU 70 via the input port include the following. An ignition signal from the ignition switch 80. A shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81. Accelerator opening degree Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83. The brake pedal position BP from the brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85. Vehicle speed V from the vehicle speed sensor 88. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52.

  The thus configured hybrid vehicle 20 of the embodiment travels in a hybrid travel mode (HV travel) that travels with the operation of the engine 22 or in an electric travel mode (EV travel) that travels while the operation of the engine 22 is stopped.

  When traveling in the HV traveling mode, the HVECU 70 performs drive control as follows. First, the HVECU 70 sets a required torque Tr * required for traveling based on the accelerator opening Acc and the vehicle speed V, and sets the rotational speed Nr of the drive shaft 36 (for example, the rotation of the motor MG2) to the set required torque Tr *. The traveling power Pdrv * required for traveling is calculated by multiplying the number Nm2 and the rotational speed obtained by multiplying the vehicle speed V by the conversion coefficient. Next, the required power required for the vehicle by subtracting the charge / discharge required power Pb * (positive value when discharging from the battery 50) based on the storage ratio SOC of the battery 50 from the calculated traveling power Pdrv *. Set Pe *. Next, the required speed Pe * is output from the engine 22 and the required torque Tr * is output to the drive shaft 36 within the range of the input / output limits Win and Wout of the battery 50. Target torque Te * and torque commands Tm1 * and Tm2 * for motors MG1 and MG2 are set. Then, the motors MG1 and MG2 are transmitted to the engine ECU 24 and the motor ECU 40 so that they can be driven at a target drive point consisting of the rotational speeds Nm1 and Nm2 and the torque commands Tm1 * and Tm2 *. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te *, controls the intake air amount, fuel injection control, and ignition of the engine 22 so that the engine 22 is operated by the target rotational speed Ne * and the target torque Te *. Control and so on. Receiving the torque commands Tm1 * and Tm2 *, the motor ECU 40 performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *. During traveling in the HV traveling mode, when the stop condition of the engine 22 is satisfied, for example, when the required power Pe * is less than the stop threshold value Pstop, the operation of the engine 22 is stopped and the traveling in the EV traveling mode is performed. Transition.

  During travel in the EV travel mode, the HVECU 70 performs drive control as follows. First, the HVECU 70 sets the required torque Tr * based on the accelerator opening Acc and the vehicle speed V, sets a value 0 to the torque command Tm1 * of the motor MG1, and within the range of the input / output limits Win and Wout of the battery 50. The torque command Tm2 * of the motor MG2 is set so that the required torque Tr * is output to the drive shaft 36. Then, the set torque commands Tm1 * and Tm2 * are transmitted to the motor ECU 40 in the same manner as when traveling in the HV traveling mode. Then, the motor ECU 40 that receives the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *. When traveling in the EV traveling mode, the engine 22 is turned on when the engine 22 starting condition is satisfied, for example, when the required power Pe * calculated in the same manner as in the traveling in the HV traveling mode reaches a starting threshold value Pstart or more. Start and shift to traveling in the HV traveling mode.

  Here, switching control of the inverters 41 and 42 will be described. In the embodiment, the motor ECU 40 selects one control mode from a plurality of control modes based on the rotational speeds Nm1, Nm2 of the motors MG1, MG2 and the torque commands Tm1 *, Tm2 *, and switches the inverters 41, 42. Control. Here, the control modes of the inverters 41 and 42 are respectively set to the sine wave control mode by the pulse width modulation (PWM) control by the triangular wave comparison and the amplitude of the triangular wave in order from the region where the motor rotation speed and torque are low, according to the maps not shown. An overmodulation control mode in which the inverter is switched with a PWM signal as an overmodulated voltage generated by generating and converting a sinusoidal output voltage command value with an amplitude exceeding, and the inverter is switched with a rectangular wave voltage having a voltage phase corresponding to the torque command It is predetermined that the rectangular wave control mode is selected. Furthermore, in the sine wave control mode of the inverters 41 and 42, a synchronous carrier PWM control method, which is a method of changing the frequency (carrier frequency) of a triangular wave as a carrier in synchronization (proportional) with the rotational speed of the motor, There is an asynchronous carrier PWM control system that uses a predetermined carrier frequency and is not synchronized with the rotational speed of the motor. In the embodiment, in the asynchronous carrier PWM control system, the frequency Fc1 is used when the motor speed is less than the threshold value Nref, and the frequency Fc2 is used when the motor speed is equal to or greater than the threshold value Nref. Further, in the synchronous carrier PWM control system, a triangular waveform corresponding to a relatively small number of cycles (for example, 6 or 8) within a range in which the inverter can be controlled satisfactorily is one cycle of the output voltage command value in the form of a sine wave. The carrier frequency is determined so as to be included in When the synchronous carrier PWM control method is used, the controllability of the motor by the inverter can be improved, and the frequency depends on the number of rotations of the motor. Therefore, the frequency should be reduced compared to the asynchronous carrier PWM control method. Can do. For this reason, the switching loss of an inverter can be made small.

  Next, the switching of the asynchronous carrier PWM control method and the synchronous carrier PWM control method is performed when the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly when the switching control of the inverters 41 and 42 is performed in the sine wave control mode. The operation at that time will be described. FIG. 3 is a flowchart illustrating an example of an inverter control method switching routine executed by the motor ECU 40 when the switching control of the inverters 41 and 42 is performed in the sine wave control mode. This routine is performed individually for the inverter 41 that drives the motor MG1 and the inverter 42 that drives the motor MG2. In the following description of this routine, the target motor of the motors MG1 and MG2 is simply referred to as “motor”, and the target inverter of the inverter 41 and inverter 42 is simply referred to as “inverter”.

  When the inverter control system switching routine is executed, the motor ECU 40 firstly sets data necessary for switching the inverter control system such as the accelerator opening degree Acc, the motor rotational speed Nm, the motor rotational acceleration αm, and the current carrier frequency Fc. Is input (step S100). Here, the rotational acceleration αm of the motor is calculated as the amount of change per unit time of the rotational speed Nm of the motor in the embodiment. Subsequently, the asynchronous carrier frequency Fcset is derived according to the motor rotation speed Nm (step S110). FIG. 4 shows an example of the relationship between the carrier frequency and the motor rotation speed Nm in the asynchronous carrier PWM control system and the synchronous carrier PWM control system. As shown in FIG. 4, in the embodiment, the carrier frequency Fcset of the asynchronous carrier PWM control system is the frequency Fc1 when the motor rotation speed Nm is less than the threshold value Nref, and the frequency Fc1 when the motor rotation speed Nm is greater than or equal to the threshold value Nref. A large frequency Fc2 is used. As described above, the carrier frequency Fcset of the asynchronous carrier PWM control system is set to a small frequency Fc1 when the motor rotation speed Nm is less than the threshold value Nref. This is to reduce the switching loss as a whole by reducing the number of times of switching. Note that, as described above, the carrier frequency in the synchronous carrier PWM control method is a frequency corresponding to the rotation speed of the motor, and is smaller than the carrier frequency Fcset of the asynchronous carrier control method in order to reduce the switching loss.

  Next, it is determined whether the current control method is an asynchronous carrier PWM control method or a synchronous carrier PWM control method (step S120). If it is determined that the current control method is the asynchronous carrier PWM control method, whether the accelerator opening Acc is equal to or greater than the threshold value Aref (step S130), and whether the rotational acceleration αm of the motor is equal to or greater than the threshold value αref1. (Step S140) is determined. These two determinations determine whether or not the rotational speed Nm of the motor is rapidly increasing, and the threshold value Aref and the threshold value αref are appropriately set according to the specifications of the motor. If the accelerator opening Acc is less than the threshold Aref, or if the rotational acceleration αm of the motor is less than the threshold αref1 even if the accelerator opening Acc is greater than or equal to the threshold Aref, the asynchronous carrier PWM control method is continued (step S150). This routine is terminated. On the other hand, when the accelerator opening Acc is equal to or greater than the threshold value Aref and the rotational acceleration αm of the motor is equal to or greater than the threshold value αref1, the control method is switched to the synchronous carrier PWM control method (step S160), and this routine is terminated.

  If it is determined in step S120 that the current control method is the synchronous carrier PWM control method, first, the frequency difference ΔF is calculated by subtracting the carrier frequency Fc at that time from the carrier frequency Fcset of the asynchronous carrier PWM control method ( Step S170). Subsequently, it is determined whether the rotational acceleration αm of the motor is less than the threshold value αref2 (step S180) and whether the frequency difference ΔF is less than the threshold value Fref (step S190). Here, the threshold value Fcset is determined in advance as a difference in carrier frequency that does not cause the occupant to feel uncomfortable with respect to vibration and abnormal noise that may occur when switching from the synchronous carrier PWM control method to the asynchronous carrier PWM method. In the example, the difference between the frequency Fc1 and the frequency Fc2 used as the carrier frequency Fcset of the asynchronous carrier PWM control method is used. If the motor rotational acceleration αm is greater than or equal to the threshold αref2 or if the frequency difference ΔF is greater than or equal to the threshold Fref even when the motor rotational angular velocity αm is less than the threshold αref, the synchronous carrier PWM control method is continued (step S200). ), This routine is terminated. On the other hand, when the rotational acceleration αm of the motor is less than the threshold value αref2 and the frequency difference ΔF is less than the threshold value Fref, the asynchronous carrier PWM control method is switched (step S210), and this routine is terminated.

  In FIG. 4, when switching from the synchronous carrier PWM control method to the asynchronous carrier PWM control method when the rotational speed Nm of the motor is the rotational speed N1, the frequency difference ΔF is less than the threshold value Fref, and thus immediately from the synchronous carrier PWM control method. The carrier frequency Fc is set to the frequency Fc2 by switching to the carrier PWM control method. When switching from the synchronous carrier PWM control system to the asynchronous carrier PWM control system when the motor rotational speed Nm is the rotational speed N2, the frequency difference ΔF is equal to or greater than the threshold value Fref. Switching to the method is prohibited and the synchronous carrier PWM control method is continued. When the motor rotation speed Nm decreases and becomes less than the threshold value Nref, the frequency difference ΔF also becomes less than the threshold value Fref. Therefore, the synchronous carrier PWM control method is switched to the asynchronous carrier PWM control method at that timing. In this way, by switching after waiting for the frequency difference ΔF to be less than the threshold value Fref, it is possible to suppress inconveniences (occurrence of vibration and abnormal noise) due to the frequency difference ΔF being equal to or greater than the threshold value Fref.

  As described above, the inverter control method switching routine of FIG. 3 is executed individually for the inverter 41 that drives the motor MG1 and the inverter 42 that drives the motor MG2. Since the motor MG2 is attached to the drive shaft 36, the rotational speed Nm2 of the motor MG2 has a linear relationship with the vehicle speed V, but the motor MG1 is a sun gear of the planetary gear 30 that can rotate independently of the drive shaft 36. Since it is attached, it does not have a linear relationship with the vehicle speed V. Therefore, as in the embodiment, when switching from the synchronous carrier PWM control method to the asynchronous carrier PWM control method, it is determined whether the rotational acceleration αm of the motor is less than the threshold value αref2 and the frequency difference ΔF is less than the threshold value Fref. Therefore, even when switching the control method of the inverter 41 that drives the motor MG1 that is not linked to the vehicle speed V, the vibration and the difference that can occur when switching from the synchronous carrier PWM control method to the asynchronous carrier PWM control method are used. Generation of sound can be suppressed.

  In the hybrid vehicle 20 of the embodiment described above, when switching from the synchronous carrier PWM control method to the asynchronous carrier PWM control method, the difference (frequency difference) ΔF between the carrier frequency Fc at that time and the carrier frequency Fcset of the asynchronous carrier PWM control method. Calculate When the frequency difference ΔF is equal to or greater than the threshold value Fref, the switching from the synchronous carrier PWM control method to the asynchronous carrier PWM control method is prohibited and the synchronous carrier PWM control method is continued. After the frequency difference ΔF reaches less than the threshold value Fref, Switching from the synchronous carrier PWM control system to the asynchronous carrier PWM control system. Thereby, when the frequency difference ΔF is equal to or greater than the threshold value Fref, it is possible to suppress the occurrence of vibrations and abnormal noise that may occur by switching from the synchronous carrier PWM control method to the asynchronous carrier PWM control method.

  In the hybrid vehicle 20 of the embodiment, the frequency Fc1 and the frequency Fc2 used as the carrier frequency Fcset of the asynchronous carrier PWM control method are used as the threshold Fref of the frequency difference ΔF used for the determination when switching from the synchronous carrier PWM control method to the asynchronous carrier PWM control method. The difference between is used. However, the threshold value Fref is not limited to the difference between the frequency Fc1 and the frequency Fc2 used as the carrier frequency Fcset of the asynchronous carrier PWM control method, and the degree to which vibration and noise that may occur at the time of switching the control method are suppressed. It may be set appropriately according to the above.

  In the hybrid vehicle 20 of the embodiment, as the carrier frequency Fcset of the asynchronous carrier PWM control system, the frequency Fc1 is used when the motor rotation speed Nm is less than the threshold value Nref, and the frequency Fc2 is used when the motor rotation speed Nm is equal to or greater than the threshold value Nref. It was. However, since the carrier frequency Fcset of the asynchronous PWM control method may be a predetermined frequency, the carrier frequency Fcset may be a constant frequency regardless of the motor rotation speed Nm, or three or more steps with respect to the motor rotation speed Nm. It is good also as a frequency with these steps.

  In the embodiment, the hybrid vehicle 20 having the drive device is described. However, the hybrid vehicle 20 includes an electric motor and an inverter that drives the electric motor, and is controlled by any one of a plurality of control methods including a synchronous carrier PWM control method and an asynchronous carrier PWM control method. Since any drive device that controls the inverter so that the electric motor is driven may be used, the present invention may be applied to a drive device that is not mounted on an automobile.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of drive devices.

  20 hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 40 motor electronic control unit (motor ECU), 41, 42 Inverter, 46 Capacitor, 50 Battery, 52 Battery electronic control unit (battery ECU), 54 Power line, 70 Hybrid electronic control unit, 80 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, D11 to D16, D21 to D26 diode, 11~T16, T21~T26 transistor, MG1, MG2 motor.

Claims (1)

Switching a plurality of switching elements of the inverter by a pulse width modulation control method using an electric motor, an inverter having a plurality of switching elements and driving the motor, and a carrier frequency changed in synchronization with the rotation speed of the motor The electric motor according to any one of a plurality of control methods including a synchronous carrier PWM control method that performs switching and a asynchronous carrier PWM control method that switches a plurality of switching elements of the inverter by a pulse width modulation control method using a predetermined carrier frequency. And a control means for controlling the inverter so as to be driven,
The control means, when switching the control of the inverter from the synchronous carrier PWM control method to the asynchronous carrier PWM control method, a frequency difference between a carrier frequency by the synchronous carrier PWM control method and a carrier frequency by the asynchronous carrier PWM control method Is switched from the synchronous carrier PWM control method to the asynchronous carrier PWM control method to continue the synchronous carrier PWM control method after the frequency difference reaches less than the predetermined value. Means for switching from the synchronous carrier PWM control method to the asynchronous carrier PWM control method.
A drive device characterized by that.

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