JP5418206B2 - Motor control device - Google Patents

Description

  The present invention relates to a technology of a motor control device.

  2. Description of the Related Art In recent years, electric vehicles, hybrid vehicles, fuel cell vehicles, and the like are equipped with devices that drive and control motors in order to drive the motors with high efficiency.

  For example, in Patent Documents 1 and 2, a DC voltage from a battery is stepped up / down by a step-up / down converter to generate a motor operating voltage, the motor operating voltage is converted to an AC voltage by an inverter, and the motor is driven and controlled. An apparatus configuration is disclosed. In such a configuration, it is necessary to provide a smoothing capacitor for stabilizing the motor operating voltage on the output side of the converter.

  For example, Patent Document 3 proposes a device in which an overvoltage is not applied to a smoothing capacitor even when a large power supply voltage is erroneously applied to a device that drives and controls a motor.

JP 2003-244801 A Japanese Patent Laying-Open No. 2005-210779 JP 2008-17626 A

  However, in a conventional motor drive control device, when the torque command value of the motor fluctuates sharply (for example, execution or stop of vibration suppression control to suppress vehicle vibration, power limit control, vehicle speed change, etc. It is not considered to suppress fluctuations in the motor command voltage caused by When the motor command voltage exceeds the upper limit criteria of the command voltage, the smoothing capacitor may be destroyed.

  SUMMARY An advantage of some aspects of the invention is that it provides a motor drive control device that suppresses steep fluctuations in the torque command value of the motor.

  The motor control device of the present invention includes an inverter that converts a DC voltage into an AC voltage for driving the motor, a converter that variably controls the DC voltage input to the inverter according to a voltage command value, and the converter A smoothing capacitor connected to a power supply line to the inverter, control means for controlling the inverter so that the motor outputs torque based on a torque command value, and a voltage command criterion value at a predetermined control timing; A calculating means for calculating a fluctuation rate A of the torque command value by calculating a smoothing capacitor power based on a deviation from the voltage command value and dividing the calculated smoothing capacitor power by the number of rotations of the motor; The means adjusts the torque command value based on the torque command value fluctuation rate A as necessary.

  Further, in the motor control device, the control means compares a preset normal torque command value variation rate with the calculated torque command value variation rate A, and the calculated torque command value variation rate A is small. In this case, it is preferable to adjust the torque command value based on the torque command value fluctuation rate A.

  Further, in the motor control device, the calculating means calculates and calculates the smoothing capacitor power by replacing a voltage command value used when calculating the smoothing capacitor power with an actual operating voltage at which the motor operates. It is preferable to calculate the fluctuation rate B of the torque command value by dividing the smoothing capacitor power by the number of rotations of the motor.

  In the motor control apparatus, the control means includes state estimation means for estimating a state in which the torque command value fluctuates sharply, and the calculation means in addition to the calculation of the torque command value fluctuation rate A, The smoothing capacitor power based on the deviation between the voltage command criterion value and the actual operating voltage at which the motor operates is calculated, and the calculated smoothing capacitor power is divided by the number of rotations of the motor, whereby the fluctuation rate B of the torque command value is obtained. And the control means adjusts the torque command value based on the torque command value variation rate B when the state estimation means estimates that the torque command value is in a state of steep fluctuation. When it is estimated that the torque command value does not fluctuate rapidly, the torque command value is preferably adjusted based on the torque command value variation rate A.

  According to the present invention, it is possible to suppress a steep fluctuation in the torque command value of the motor. As a result, even if the torque command value of the motor fluctuates, the motor command voltage does not exceed the upper limit criteria of the command voltage, and it is possible to prevent the smoothing capacitor from being destroyed.

It is a figure which shows an example of schematic structure of a power supply device provided with the control apparatus of the motor which concerns on this embodiment. It is a figure for demonstrating the relationship between a torque command value and a voltage command value. It is a flowchart explaining an example of operation | movement of the control apparatus of the motor which concerns on this embodiment. It is a flowchart explaining another example of operation | movement of the control apparatus of the motor which concerns on this embodiment. It is a flowchart explaining another example of operation | movement of the control apparatus of the motor which concerns on this embodiment. It is a flowchart explaining another example of operation | movement of the control apparatus of the motor which concerns on this embodiment.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram illustrating an example of a schematic configuration of a power supply device including a motor control device according to the present embodiment. A power supply device 1 shown in FIG. 1 includes a power storage device 10, motor generators 12a and 12b, and a motor control device. The motor control device includes a converter 14, a smoothing capacitor 16, inverters 18 a and 18 b, and an ECU (Electronic Control Unit) 20. The power supply device is not particularly limited, but is mounted on a vehicle such as an electric vehicle or a hybrid vehicle.

  The power storage device 10 includes a secondary battery such as a lead secondary battery, a lithium ion secondary battery, or a nickel hydride secondary battery. However, the power storage device 10 is not necessarily limited thereto, and may be another type of power storage device such as a capacitor represented by an electric double layer capacitor.

  The motor generators 12a and 12b include a motor generator that mainly functions as a motor and a motor generator that mainly functions as a generator. The motor generators 12a and 12b function as a generator or function as a motor according to the traveling state of the vehicle. To do.

  Various sensor outputs from various sensors indicating the driving situation and the vehicle situation are input to the ECU 20. The various sensor outputs are accelerator depression amount, vehicle speed, and the like. Then, the ECU 20 sets a torque command value for the motor generator based on various sensor outputs. ECU 20 determines a voltage command value to motor generators 12a and 12b from the motor rotation speed, torque command value, and the like.

  The ECU 20 controls the operation of the inverters 18a and 18b so that the motor generators 12a and 12b output torque according to the set torque command value, and the motor generators 12a and 12b operate according to the set voltage command value. Thus, it has a function as a control means for controlling the operation of the converter 14.

  Converter 14 receives the input voltage from power storage device 10, and according to the voltage command value determined by ECU 20, raises or lowers the input voltage to generate an operating voltage for the motor generator, and outputs it between power supply wires 22 and 23.

  The smoothing capacitor 16 is connected between the power supply wires 22 and 23. The smoothing capacitor 16 smoothes the motor operating voltage output from the converter 14 between the power supply wires 22 and 23.

  Inverters 18a and 18b convert the motor operating voltage (DC voltage) output from converter 14 between power supply lines 22 and 23 into AC voltage for driving motor generators 12a and 12b. The inverters 18a and 18b receive a control signal from the ECU 20 so that a motor current that generates torque according to the torque command value set by the ECU 20 flows.

  FIG. 2 is a diagram for explaining the relationship between the torque command value and the voltage command value. The torque command value set by the ECU 20 depending on the execution or stop of the vibration suppression control for suppressing the vehicle vibration, the power limit control, the speed change of the vehicle speed, etc., is steep as shown in the one-dot chain line A in the upper part of FIG. May vary. Conventionally, the fluctuation rate when the torque command value fluctuates sharply is set in advance (for example, torque command maximum value / 24 msec), but the torque command value is set at such a generally set fluctuation rate. When it fluctuates, as shown in the one-dot chain line B in the lower part of FIG. 2, the voltage command value to the motor generators 12a and 12b may rise and exceed the voltage command criterion value. If the voltage command value exceeds the voltage command criteria value, an overvoltage is applied to the smoothing capacitor 16 and the smoothing capacitor 16 may be destroyed.

In this embodiment, in order to suppress the steep fluctuation of the torque command value as described above, the ECU 20 causes the deviation between the voltage command criterion value (VH ₀ ) and the voltage command value (VH ₁ ) at a predetermined control timing. The smoothing capacitor power (P) based on the above is calculated, and the torque command value fluctuation rate A is calculated by dividing the calculated smoothing capacitor power (P) by the motor rotation speed (N). That is, the ECU 20 has a function as calculation means for calculating the torque command value fluctuation rate A. The smoothing capacitor power (P) based on the deviation between the voltage command criterion value (VH ₀ ) and the voltage command value (VH ₁ ) is obtained by the following equation (1), and the torque command value variation rate A is expressed by the following equation (2 ).
P = 1/2 × C (VH ₀ ² −VH ₁ ² ) / ΔT (1)
C: Smoothing capacitor capacity ΔT: Control cycle (predetermined control timing)
Torque command value fluctuation rate A = P / N (2)

Further, in the present embodiment, the smoothing capacitor power can be accurately calculated in consideration of the influence of the fluctuation of the voltage command value due to the control disturbance, so that the voltage command value (VH ₁ ) of the above formula ( ₁ ) is replaced. Thus, the actual operating voltage at which the motor generators 12a and 12b operate (that is, the operating voltage of the motor output from the converter 14 is detected from, for example, a voltage sensor installed in the motor generators 12a and 12b). Thus, the torque command value fluctuation rate B may be calculated by calculating the smoothing capacitor power (P) and dividing the smoothing capacitor power (P) by the motor rotation speed (N). The smoothing capacitor power (P) based on the deviation between the voltage command criterion value (VH ₀ ) and the actual operating voltage (VH ₂ ) at which the motor generators 12a and 12b operate is obtained by the following equation (3).
P = 1/2 × C (VH ₀ ² −VH ₂ ² ) / ΔT (3)

  Then, the ECU 20 adjusts the torque command value based on the torque command value fluctuation rate A or B as necessary. When adjusting the torque command value based on the torque command value fluctuation rate A or B as necessary, for example, the calculated torque command value fluctuation rate A or B is more than the preset torque command value fluctuation rate. In the case where the torque command value is small, the torque command value may fluctuate abruptly due to execution or stop switching of vibration suppression control for suppressing vehicle vibration, power limit control, vehicle speed change, or the like. Here, the ECU 20 inputs driving status data such as execution or stop switching of vibration suppression control to suppress vehicle vibration, power limit control, vehicle speed shift, and the like, and estimates a state in which the torque command value fluctuates sharply. It has a function as a state estimation means.

  ECU 20 controls inverters 18a and 18b so as to output torque based on the torque command value adjusted by motor generators 12a and 12b.

  FIG. 3 is a flowchart for explaining an example of the operation of the motor control device according to the present embodiment.

As shown in FIG. 3, first, in step S10, the smoothing capacitor power (P) based on the deviation between the voltage command criterion value (VH ₀ ) and the voltage command value (VH ₁ ) is determined by the ECU 20 at a predetermined control timing. The torque command value fluctuation rate A is calculated by dividing the smoothing capacitor power (P) by the motor rotation speed (N). Then, the ECU 20 compares the preset torque command value fluctuation rate (for example, torque command maximum value / 24 msec) with the calculated torque command value fluctuation rate A. If the preset torque command value variation rate is smaller than the calculated torque command value variation rate A, the process proceeds to step S12, where the ECU 20 performs torque based on the preset torque command value variation rate. The command value is adjusted. On the other hand, if the calculated torque command value variation rate A is smaller than the preset torque command value variation rate, the process proceeds to step S14, where the ECU 20 determines the torque command value based on the calculated torque command value variation rate A. Is adjusted. In step S16, the inverters 18a and 18b are controlled by the ECU 20 so as to output torque based on the torque command values adjusted by the motor generators 12a and 12b.

  FIG. 4 is a flowchart illustrating another example of the operation of the motor control device according to the present embodiment.

As shown in FIG. 4, first, in step S20, the smoothing capacitor based on the deviation between the voltage command criterion value (VH ₀ ) and the actual operating voltage at which the motor generators 12a and 12b operate at a predetermined control timing by the ECU 20. The power (P) is calculated, and the torque command value fluctuation rate B is calculated by dividing the smoothing capacitor power (P) by the motor rotation speed (N). Then, the ECU 20 compares the preset torque command value fluctuation rate (for example, torque command maximum value / 24 msec) with the calculated torque command value fluctuation rate B. If the preset torque command value variation rate is smaller than the calculated torque command value variation rate B, the process proceeds to step S22, where the ECU 20 performs torque based on the preset torque command value variation rate. The command value is adjusted. On the other hand, if the calculated torque command value variation rate B is smaller than the preset torque command value variation rate, the process proceeds to step S24, where the ECU 20 determines the torque command value based on the calculated torque command value variation rate B. Is adjusted. In step S26, the inverters 18a and 18b are controlled by the ECU 20 so as to output torque based on the torque command values adjusted by the motor generators 12a and 12b.

  FIG. 5 is a flowchart illustrating another example of the operation of the motor control device according to the present embodiment.

As shown in FIG. 5, first, in step S30, the ECU 20 calculates the smoothing capacitor power (P) based on the deviation between the voltage command criterion value (VH ₀ ) and the voltage command value (VH ₁ ) at a predetermined control timing. The torque command value fluctuation rate A is calculated by dividing the smoothing capacitor power (P) by the motor rotation speed (N). Further, the ECU 20 calculates a smoothing capacitor power (P) based on a deviation between the voltage command criterion value (VH ₀ ) and the actual operating voltage at which the motor generators 12a and 12b operate at a predetermined control timing. The torque command value fluctuation rate B is calculated by dividing (P) by the motor rotation speed (N). Then, the ECU 20 estimates a state in which the torque command value fluctuates abruptly due to execution or stop switching of vibration suppression control for suppressing vehicle vibration, power limit control, speed change of the vehicle speed, and the like. If it is estimated that the fluctuation is steep, the process proceeds to step S32, where the torque command value is adjusted based on the calculated torque command value fluctuation rate B. On the other hand, when the ECU 20 estimates that the torque command value does not change sharply, the process proceeds to step S34, where the torque command value is adjusted based on the calculated torque command value fluctuation rate A. In step S36, the inverters 18a and 18b are controlled by the ECU 20 so as to output torque based on the torque command values adjusted by the motor generators 12a and 12b.

  FIG. 6 is a flowchart illustrating another example of the operation of the motor control device according to the present embodiment.

  As shown in FIG. 6, the ECU 20 estimates a state in which the torque command value fluctuates sharply due to execution or stop switching of vibration suppression control to suppress vehicle vibration, power limit control, vehicle speed shift, and the like. When it is estimated that the torque command value fluctuates sharply, the process proceeds to step S40, and the torque command value is adjusted based on an arbitrary torque command value fluctuation rate. On the other hand, if the ECU 20 estimates that the torque command value does not change sharply, the process proceeds to step S42, where the torque is based on a preset torque command value variation rate (for example, torque command maximum value / 24 msec). The command value is adjusted. In step S44, the inverters 18a and 18b are controlled by the ECU 20 so as to output torque based on the torque command values adjusted by the motor generators 12a and 12b.

  1 power supply device, 10 power storage device, 12a, 12b motor generator, 14 converter, 16 smoothing capacitor, 18a, 18b inverter, 20 ECU, 22, 23 power supply wiring.

Claims (1)

An inverter that converts a DC voltage into an AC voltage for driving the motor;
A converter that variably controls the DC voltage input to the inverter according to a voltage command value;
A smoothing capacitor connected to a power supply line from the converter to the inverter;
Control means for controlling the inverter so that the motor outputs torque based on a torque command value;
By calculating the smoothing capacitor power based on the deviation between the voltage command criterion value and the voltage command value at a predetermined control timing, and dividing the calculated smoothing capacitor power by the number of rotations of the motor, the fluctuation rate A of the torque command value is obtained. Calculating means for calculating,
The control means includes state estimation means for estimating a state where the torque command value fluctuates sharply,
In addition to calculating the torque command value variation rate A, the calculating means calculates a smoothing capacitor power based on a deviation between a voltage command criterion value and an actual operating voltage at which the motor operates, and calculates the calculated smoothing capacitor power to the motor. By dividing by the number of revolutions, the torque command value variation rate B is calculated,
The control means adjusts the torque command value based on the torque command value fluctuation rate B when the state estimation means estimates that the torque command value is in a state of steep fluctuation, and the torque command value A motor control device that adjusts the torque command value based on the torque command value fluctuation rate A when it is estimated that the value does not fluctuate rapidly .

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