JP2019092296A - Driving device - Google Patents

Abstract

To suppress the occurrence of resonance due to a vibration component based on the number of rotations of a dynamo-electric motor and an LC circuit from a reactor and a capacitor for smoothing.SOLUTION: A driving device comprises: a dynamo-electric motor; a power storage device; a reactor; and a capacitor device including a first capacitor for smoothing a voltage of a power supplied to the dynamo-electric motor, and a switching element and a second capacitor serially connected to each other, the capacitor device parallelly connected to the first capacitor. The switching element of the capacitor device is switching-controlled so that a frequency of a vibration component based on the number of rotations of the dynamo-electric motor exceeds a resonance region of an LC resonance by the reactor, the first capacitor, and the capacitor device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a drive device, and more particularly, to a drive device including a boost converter having a reactor for boosting power from a power storage device and supplying the power to a motor, and a capacitor for smoothing a voltage of output power from the boost converter. .

  Conventionally, as a drive device of this type, an engine and a first motor are connected to a drive shaft via a planetary gear and a second motor is mounted on a vehicle connected to the drive shaft to boost power from a battery. One has been proposed which comprises a boost converter for supplying the first and second motors, and a capacitor for smoothing the voltage of the output power from the boost converter (see, for example, Patent Document 1). In this device, the output torque of the second motor is reduced as much as possible when the number of revolutions of the second motor is in a resonance region where LC resonance occurs between the reactor of the boost converter and the smoothing capacitor. By increasing the power of the above, torque required for the drive shaft is output while suppressing LC resonance.

JP, 2013-99042, A

  However, although the above-described drive device suppresses the resonance by reducing the torque of the second motor relating to the resonance region, it can not be applied to a drive device having a configuration in which the motor torque can not be reduced. In this case, when the frequency of the vibration component based on the number of revolutions of the motor falls within the resonance region, it is conceivable to change the number of revolutions of the motor. Will become larger.

  The drive device according to the present invention has as its main object to suppress the occurrence of resonance due to a vibration component based on the number of revolutions of a motor, an LC circuit with a reactor and a smoothing capacitor.

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

The driving device of the present invention is
Electric motor,
A storage device,
A reactor,
A first capacitor for smoothing the voltage of the power supplied to the motor;
A controller for controlling the motor;
A driving device comprising
A capacitor device having a switch element and a second capacitor connected in series, and connected in parallel to the first capacitor;
The control device performs switching control of a switch element of the capacitor device such that a frequency of a vibration component based on the number of rotations of the motor is outside a resonance region of LC resonance by the reactor, the first capacitor and the capacitor device.
It is characterized by

  The drive device according to the present invention includes a motor, a power storage device, a reactor, and a first capacitor that smoothes the voltage of output power from the power storage device, and further, a capacitor connected in parallel with the first capacitor. It has an apparatus. In this capacitor device, the switch element and the second capacitor are connected in series. Then, switching control of the switch element of the capacitor device is performed so that the frequency of the vibration component based on the rotational speed of the motor is outside the resonance region of LC resonance by the reactor, the first capacitor and the capacitor device. Assuming that the capacitance of the first capacitor is C1 and the capacitance of the second capacitor is C2, the LC resonant frequency is expressed by the following equation (1) to turn off the switch element of the capacitor device. The LC resonant frequency is expressed by equation (2) when the switch element of the switch element is turned on. Therefore, the frequency of the vibration component based on the rotational speed of the motor does not belong to the first resonance region including the LC resonance frequency according to equation (1), and in the second resonance region including the LC resonance frequency according to equation (2) Switching control of the switch element of the capacitor device may be performed so as not to belong. As a result, it is possible to suppress the occurrence of resonance due to the vibration component based on the rotational speed of the motor, the reactor, and the LC circuit by the smoothing capacitor. Here, an RB-IGBT (Reverse-Block Insulated Gate Bipolar Transistor) can be used as a switch element. In addition, as the reactor, a reactor component in the storage device, a reactor included in a step-up converter for boosting the power from the storage device and supplying it to the motor, and the like are meant.

It is a block diagram which shows the outline of a structure of the electric vehicle 20 which mounts the drive device as one Example of this invention. It is explanatory drawing which shows an example of the electric 6th-order fluctuation torque with respect to motor rotation speed Nm at the time of carrying out rectangular wave control of 4 pole pair motor. 6 is a capacitor switching processing routine executed by the electronic control unit 50. It is explanatory drawing which shows an example of the relationship between the rotation speed Nm of the motor 32, the electric 6th-order fluctuation frequency, and the 1st resonance region.

  Next, modes for carrying out the present invention will be described using examples.

  FIG. 1 is a block diagram showing an outline of the configuration of an electric vehicle 20 equipped with a drive device as an embodiment of the present invention. As illustrated, the electric vehicle 20 of the embodiment includes a motor 32, an inverter 34, a battery 36 as a power storage device, a boost converter 40, and an electronic control unit 50.

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

  The inverter 34 is used to drive the motor 32. The inverter 34 is connected to the boost converter 40 via the high voltage side power line 42, and is connected in parallel to the transistors T11 to T16 as six switching elements and to the six transistors T11 to T16 respectively. Diodes D11 to D16. The transistors T11 to T16 are arranged in pairs of two so as to be on the source side and the sink side with respect to the positive electrode side line and the negative electrode side line of the high voltage side power line 42, respectively. Further, each of three-phase coils (U-phase, V-phase, W-phase coils) of the motor 32 is connected to each of connection points of the pair of transistors T11 to T16. Therefore, when the voltage is applied to the inverter 34, the ratio of the on time of the paired transistors T11 to T16 is adjusted by the electronic control unit 50, so that a rotating magnetic field is formed in the three-phase coil. 32 is rotationally driven. A smoothing capacitor 46 is attached to the positive electrode side line and the negative electrode side line of the high voltage side power line 42, and a capacitor 47 having a capacitor switch Trb is attached to be connected in parallel to the capacitor 46 . The capacitor switch Trb is configured as a reverse-block insulated gate bipolar transistor (RB-IGBT), and switches between parallel connection of the capacitor 47 to the capacitor 46 and release thereof.

  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 side power line 44. A smoothing capacitor 48 is attached to the positive side line and the negative side line of the low voltage side 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, and two diodes connected in parallel to the two transistors T31 and T32 and the two transistors T31 and T32 respectively. D31, D32, and a reactor L. The transistor T <b> 31 is connected to the positive electrode side line of the high voltage side power line 42. The transistor T32 is connected to the transistor T31 and the negative electrode side line of the high voltage side power line 42 and the low voltage side power line 44. The reactor L is connected to a connection point between the transistors T31 and T32 and a positive electrode side line of the low voltage side power line 44. The boost converter 40 boosts the power of the low voltage side power line 44 and supplies it to the high voltage side power line 42 by adjusting the ratio of the on time of the transistors T31 and T32 by the electronic control unit 50. The power of the high voltage side power line 42 is stepped down and supplied to the low voltage side power line 44 or the like.

  The electronic control unit 50 is configured as a microprocessor centering on the CPU 50a, and includes, in addition to the CPU 50a, a ROM 50b for storing processing programs, a RAM 50c for temporarily storing data, and an input / output port not shown. Signals from various sensors are input to the electronic control unit 50 through input ports. As a signal input to the electronic control unit 50, for example, the rotational position θm from a rotational position detection sensor (for example, resolver) 32a that detects the rotational position of the rotor of the motor 32 or the phase current of each phase of the motor 32 Phase currents Iu and Iv from the current sensors 32u and 32v to be detected can be mentioned. 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. Furthermore, the voltage VH of the high voltage side power line 42 from the voltage sensor 46a attached to the high voltage side power line 42, the capacitor 48 from the voltage sensor 48a attached between the terminals of the capacitor 48 (low voltage side power line 44) can also be mentioned. In addition, the ignition signal from the ignition switch 60 and the shift position SP from the shift position sensor 62 that detects the operation position of the shift lever 61 can also be mentioned. In addition, the accelerator opening Acc from the accelerator pedal position sensor 64 for detecting the amount of depression of the accelerator pedal 63, the brake pedal position BP from the brake pedal position sensor 66 for detecting the amount of depression of the brake pedal 65, and the vehicle speed sensor 68 The vehicle speed V can also be mentioned. Various control signals are output from the electronic control unit 50 through the output port. Examples of the signal output from the electronic control unit 50 include a switching control signal to the transistors T11 to T16 of the inverter 34 and a switching control signal to the transistors T31 and T32 of the step-up converter 40. The electronic control unit 50 calculates the electrical angle θe and the rotational speed Nm of the motor 32 based on the rotational position θm of the rotor of the motor 32 from the rotational position detection sensor 32a.

  In the electric vehicle 20 of the embodiment configured in this manner, the electronic control unit 50 sets the required torque Td * required for the drive shaft 26 based on the accelerator opening Acc and the vehicle speed V, and sets the required torque Td * Is limited (upper limit guard) by the upper limit torque Tmmax * for control of the motor 32 and set as the torque command Tm * of the motor 32. Then, using the torque command Tm * of the motor 32, the transistors T11 to T16 of the inverter 34 are controlled by pulse width modulation control (PWM control), overmodulation control, or rectangular wave control. Further, the electronic control unit 50 sets the target voltage VH * of the high voltage side power line 42 so that the motor 32 can be driven by the torque command Tm *, and the voltage VH of the high voltage side power line 42 becomes the target voltage VH * Thus, switching control of the transistors T31 and T32 of the boost converter 40 is performed.

  Next, the operation of the electric vehicle 20 according to the embodiment, in particular, control for suppressing resonance based on the load fluctuation frequency fm of the motor 32 by the electronic control unit 50 will be described. The load fluctuation frequency fm of the motor 32 depends on the motor, but in the case where the motor 32 is a four-pole pair motor, it has an electric sixth-order fluctuation frequency. FIG. 2 shows an electric sixth-order fluctuation torque with respect to the motor rotational speed Nm when rectangular wave control of a 4-pole pair motor capable of rectangular wave control at 2000 rpm or more is performed. As illustrated, in this example, the electric sixth-order fluctuation torque is maximal at about 3100 rpm. The resonance occurs when the electric sixth-order fluctuation frequency belongs to the resonance region of the LC circuit by the reactor L of the boost converter 40 and the capacitors 46 and 47 of the high voltage side power line 42. The resonance frequency of the LC circuit differs depending on when the capacitor switch Trb is turned off and the capacitor 47 is disconnected and when the capacitor Trb is turned on and the capacitor 47 is connected. If the inductance L of the reactor L1 and the capacitance C1 of the capacitor 46 of the high voltage side power line 42 are used, the resonance frequency fc1 when the capacitor 47 is disconnected can be calculated by the above equation (1) it can. The resonance frequency fc2 when the capacitor 47 is connected can be calculated by the above equation (2) if the capacitance C2 of the capacitor 47 is used. In the electric vehicle 20 of the embodiment, control is performed to disconnect and connect the capacitor 47 so that resonance does not occur.

  FIG. 3 shows a capacitor switching process routine executed by the electronic control unit 50. This routine is repeatedly executed every predetermined time (for example, every several tens of msec). When the capacitor switching processing routine is executed, the electronic control unit 50 inputs the number of revolutions Nm of the motor 32 (step S100), and the number of revolutions Nm of the motor 32 is the first resonance region when the capacitor 47 is disconnected. It is determined whether it belongs to (step S110). Here, the first resonance area is an area obtained by converting the resonance area including the resonance frequency fc1 when the capacitor 47 is disconnected into the rotational speed Nm of the motor 32. FIG. 4 shows an example of the relationship between the number of revolutions Nm of the motor 32, the sixth electric fluctuation frequency, and the first resonance region. In the case of a 4-pole pair motor, the load fluctuation frequency fm of the motor 32 is an electric sixth-order fluctuation frequency, and the electric sixth-order fluctuation frequency linearly changes with respect to the rotation speed Nm of the motor 32. The resonance range (range from the frequency f1 to the frequency f2) including the resonance frequency fc1 when the capacitor 47 is disconnected is, as illustrated, converted to the range of the rotation number Nm to the rotation number N2 of the motor 32 (The first resonance region). In the embodiment, the first resonance region is determined in advance, and it is determined in step S110 whether the rotation speed Nm of the motor 32 belongs to the first resonance region. Although not used in this process, in the embodiment, a region obtained by converting a resonance region including the resonance frequency fc2 when the capacitor 47 is connected into the rotational speed Nm of the motor 32 is referred to as a second resonance region. There is.

  When it is determined in step S110 that the rotational speed Nm of the motor 32 belongs to the first resonance region, the capacitor switch Trb is turned on (step S120), and the routine is ended with the capacitor 47 being connected. When the capacitor 47 is connected, the resonance region is changed from the first resonance region to the second resonance region, so that resonance based on the load fluctuation frequency fm of the motor 32 can be suppressed.

  On the other hand, when it is determined in step S110 that the rotation speed Nm of the motor 32 does not belong to the first resonance region, the capacitor switch Trb is turned off (step S130), the capacitor 47 is disconnected, and this routine is ended. . Thereby, resonance based on the load fluctuation frequency fm of the motor 32 can be suppressed.

  In the drive unit mounted on the electric vehicle 20 according to the embodiment described above, disconnection and connection are performed by the capacitor switch Trb so as to be connected in parallel to the smoothing capacitor 46 attached to the high voltage side power line 42 The capacitor 47 is provided. Then, whether or not the rotation speed Nm of the motor 32 belongs to the first resonance region, ie, the load fluctuation frequency fm of the motor 32 belongs to the resonance region including the resonance frequency fc1 of the LC circuit when the capacitor 47 is disconnected. It is determined whether the When it is determined that the rotation speed Nm of the motor 32 belongs to the first resonance region, the capacitor 47 is connected, and when it is determined that the rotation speed Nm of the motor 32 does not belong to the first resonance region Is separated. Thereby, resonance based on the load fluctuation frequency fm of the motor 32 is suppressed. As a result of these, it is possible to suppress the occurrence of resonance due to the vibration component based on the rotation speed Nm of the motor 32 and the LC circuit based on the reactor L of the boost converter 40.

  In the drive device of the embodiment, it is determined whether or not the rotation speed Nm of the motor 32 belongs to the first resonance region, and the state where the capacitor 47 is connected when the rotation speed Nm belongs to the first resonance region When it is determined that the rotational speed Nm does not belong to the first resonance region, the capacitor 47 is in a disconnected state. However, it is determined whether or not the rotation speed Nm of the motor 32 belongs to the first resonance region, and the capacitor 47 is separated when the rotation speed Nm belongs to the second resonance region. When it is determined that the rotational speed Nm does not belong to the second resonance region, the capacitor 47 may be connected. When the number of revolutions Nm of the motor 32 belongs to the first resonance region, the capacitor 47 is connected. When the number of revolutions Nm of the motor 32 belongs to the second resonance region, the capacitor 47 is disconnected. When the number of revolutions Nm of the motor 32 does not belong to either the first resonance region or the second resonance region, the energy efficiency of the state in which the capacitor 47 is connected and the state in which the capacitor 47 is disconnected are different. The higher one may be selected.

  Although the drive device of the embodiment includes the motor 32, the inverter 34, the battery 36, and the boost converter 40, the boost converter 40 may not be provided. In this case, the resonance region of the LC circuit by the reactor component of the battery 36 and the capacitor 46 may be set as a first resonance region, and the resonance region of the LC circuit by the capacitor 46 and the capacitor 47 may be set as a second resonance region. .

  In the drive device mounted on the electric vehicle 20 according to the embodiment, the battery 36 is used as the power storage device, but any device capable of storing power may be used, and a capacitor or the like may be used.

  In the embodiment, the drive unit mounted on the electric vehicle 20 including the motor 32 is used. However, the drive unit may be mounted on a hybrid vehicle equipped with an engine in addition to the motor 32, or may be mounted on a moving object such as a vehicle other than a car, a ship, or an aircraft. It may be in the form of a drive device mounted on non-moving equipment such as construction equipment.

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

  The present invention is applicable to the drive industry and the like.

  DESCRIPTION OF SYMBOLS 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, 47, 48 capacitor, 50 electronic control unit, 50a CPU, 50b ROM, 50c 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~T16, T31, T32 transistor, Trb capacitor switch.

Claims (1)

Electric motor,
A storage device,
A reactor,
A first capacitor for smoothing the voltage of the power supplied to the motor;
A controller for controlling the motor;
A driving device comprising
A capacitor device having a switch element and a second capacitor connected in series, and connected in parallel to the first capacitor;
The control device performs switching control of a switch element of the capacitor device such that a frequency of a vibration component based on the number of rotations of the motor is outside a resonance region of LC resonance by the reactor, the first capacitor and the capacitor device.
Drive device.

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