JP-7856521-B2 - Inverter device and motor drive device

Inventors

• 李 東昇
• 舟橋 佳邦
• 高木 純一

Assignees

• 日立グローバルライフソリューションズ株式会社

Dates

Publication Date

20260511

Application Date

20220805

Claims (9)

1. In an inverter device that converts DC power to AC power and outputs the AC power to a load, and is controlled by a control unit equipped with a dead time compensation function that reduces waveform distortion of the output current caused by an error voltage between the voltage command value and the output voltage due to the setting of the dead time, the control unit adds a predetermined dead time compensation amount to the voltage command value according to the polarity of the output current , The control unit, An inverter device characterized by generating the dead time compensation amount based on the third harmonic component included in the output current corresponding to a sinusoidal current command of a predetermined frequency.
2. In the inverter device according to claim 1, The control unit, An inverter device characterized by generating a sinusoidal signal with a frequency three times that is in phase with the sinusoidal current command, calculating a characteristic quantity related to the third harmonic component from the product of the output current and the sinusoidal signal, and generating the dead time compensation amount based on the characteristic quantity.
3. In the inverter device according to claim 2, The control unit, An inverter device characterized by generating the dead time compensation amount in such a way as to reduce the aforementioned feature quantity.
4. In the inverter device according to claim 2, The inverter device is characterized in that the aforementioned feature quantity is the DC component in the multiplication value.
5. In the inverter device according to claim 1, The aforementioned AC power is three-phase AC power. The aforementioned sinusoidal current command is either a d-axis current command or a q-axis current command. The inverter device is characterized in that the output current is a d-axis current command or a q-axis current command.
6. An inverter device according to claim 1, When a three-phase inverter is used in the aforementioned inverter device, The aforementioned AC power is three-phase AC power. The inverter device is characterized in that the control unit turns off one of the three phases of the upper and lower arms in the main circuit to generate the dead time compensation amount.
7. In the inverter device according to claim 1, The control unit, The generated dead time compensation amount is stored in the storage unit. An inverter device characterized by performing dead time compensation using the dead time compensation amount stored in the memory unit.
8. In a motor drive system that drives an AC motor with an inverter device, The inverter device converts DC power to AC power and outputs the AC power to the AC motor. It is controlled by a control unit that has a dead time compensation function to reduce waveform distortion of the output current caused by error voltage between the voltage command value and the output voltage due to the setting of the dead time. In dead time compensation, the control unit adds a predetermined dead time compensation amount to the voltage command value according to the polarity of the output current. The control unit, A motor drive device characterized by generating the dead time compensation amount based on the third harmonic component included in the output current corresponding to a sinusoidal current command of a predetermined frequency.
9. In the motor drive device according to claim 8, The control unit, A motor drive device characterized by generating the dead time compensation amount when the AC motor stops.

Description

This invention relates to an inverter device and a motor drive device using an inverter device. During the operation of the inverter device, a dead time is set to simultaneously turn off the semiconductor switching elements in the upper and lower arms to prevent short circuits. When a dead time is set, an error voltage occurs between the voltage command value generated by the controller and the output voltage of the inverter device. This causes waveform distortion in the output current of the inverter device. To reduce this waveform distortion, the controller performs dead time compensation. In dead time compensation, a predetermined dead time compensation amount is added to the voltage command value, depending on the polarity of the output current. The magnitude of the dead time compensation amount is influenced not only by the dead time but also by the characteristics and variations of the semiconductor switching element. Therefore, in order to set the dead time compensation amount, the characteristics of the semiconductor switching element are investigated or measured in advance, and the error voltage associated with the dead time setting is measured. In contrast, a conventional technique for setting the dead time compensation amount using a controller is known, for example, the technique described in Patent Document 1. In this technique, the amplitude of the compensation voltage is corrected so that the difference between the value of the current pulsation generated in the motor current flowing from the power converter to the motor and the current command value becomes smaller than a predetermined reference value. Japanese Patent Publication No. 2012-44785 This is a circuit diagram showing the configuration of the inverter device in Example 1.This is a functional block diagram showing the schematic configuration of the controller 7 (Figure 1).This is a functional block diagram showing the detailed configuration of the current command generator 10 (Figure 2).This is a functional block diagram showing the detailed configuration of the current controller 11 (Figure 2).This is a functional block diagram showing the detailed configuration of the dead time compensator 13 (Figure 2).This is a functional block diagram showing the detailed configuration of the dead time compensation amount identifyr 15 (Figure 2).This waveform diagram shows the operation of the dead time compensation amount identifyr 15 (Figure 6).An example of the output waveform 33 of the low-pass filter 27 (Figure 6) and an example of the corresponding dead-time compensation waveform 34 are shown when the dead-time compensation amount identifier 15 (Figure 6) is in operation.This is a circuit diagram showing the configuration of the inverter device in Example 2.This is a functional block diagram showing the schematic configuration of the controller 45 (Figure 9).This is a circuit diagram showing the overall configuration of the motor drive device, which is Example 3. The embodiments of the present invention will be described below with reference to the drawings, using Examples 1 to 3. In each figure, elements with the same reference number represent the same or similar functional components. As described below, in each embodiment, the dead time compensation amount is set based on the third harmonic component contained in the current output by the inverter device.