Power conversion device

• US 9,160,271 B2
• Filed: 01/18/2012
• Issued: 10/13/2015
• Est. Priority Date: 01/18/2012
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Yamasaki, Hisanori, Hatanaka, Keita, Kitanaka, Hidetoshi
• Primary Examiner(s): GLASS, ERICK DAVID
• Application Number:
  US14/348,956
• Publication Number:
  US 20140247003A1
• Time in Patent Office: 1,364 Days
• Field of Search: 318/802, 318/434
• US Class Current: 1/1
• CPC Class Codes: B60L 15/025 using field orientation; Vector control; Direct Torque Control [DTC]
• CPC Class Codes: B60L 9/005 Interference suppression
• CPC Class Codes: G05B 19/00 Programme-control systems
• CPC Class Codes: H02M 1/15 using active elements
• CPC Class Codes: H02M 5/4585 having a rectifier with controlled elements
• CPC Class Codes: H02P 21/05 specially adapted for damping motor oscillations, e.g. for reducing hunting
• CPC Class Codes: H02P 2207/01 Asynchronous machines
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence
• CPC Class Codes: H02P 29/50 Reduction of harmonics
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility

Abstract

A power conversion device formed of a converter for rectifying a single-phase AC voltage to a DC voltage and an inverter for driving an AC motor by converting the DC voltage to an AC voltage includes: a first compensation unit that uses a frequency component twice the frequency of the single-phase AC voltage with respect to the DC voltage outputted from the converter or a current outputted from the inverter as a compensation value for at least one of a torque command value, a current command value, a voltage command value, a frequency command value, and a phase angle command value; and a second compensation unit that uses the DC voltage outputted from the converter or a current outputted from the inverter after being subjected to low frequency cut-off processing and gain processing.

Claims

1. A power conversion device, comprising:

a converter for converting a single-phase AC voltage to a DC voltage through rectification;

an inverter for feeding a motor by converting the DC voltage as an output of the converter to an AC voltage;

a current command value generation unit for outputting a current command value for the motor according to a torque command value;

a frequency command value generation unit for outputting a frequency command value of the AC voltage for the motor according to a speed signal of the motor;

a phase angle command value generation unit for calculating a phase angle command value on the basis of speed information or axis position information of the motor;

a voltage command value generation unit for generating a voltage command value to the inverter using the current command value, the frequency command value, and the phase angle command value; and

a compensation unit for adding a compensation value to or subtracting the compensation value from at least one of the torque command value, the current command value, the voltage command value, the frequency command value, and the phase angle command value,

the compensation unit includes;

a first compensation unit for extracting a frequency component twice a frequency of the single-phase AC voltage from the DC voltage outputted from the converter or a current outputted from the inverter to apply gain processing to the extracted component, and using a result of the processing as the compensation value; and

a second compensation unit for applying low frequency cut-off processing to the DC voltage outputted from the converter or a current outputted from the inverter, using a frequency selected at or below an electric angular maximum frequency of the motor as a cut-off frequency to apply gain processing to the processed component, and using a result of the processing as the compensation value.

2. The power conversion device according to claim 1 wherein;

a d-axis current, which is a flux phase component, or a q-axis current, which is a component orthogonal to the flux phase, is extracted by subjecting the current outputted from the inverter to coordinate conversion processing so as to convert the current onto dq-axis coordinates, which are rotational biaxial coordinates using the flux phase of the motor as a reference, and either one of the d-axis current and the q-axis current is used as an input to the first compensation unit or the second compensation unit.

3. The power conversion device according to claim 1, wherein;

the second compensation means applies the low frequency cut-off processing using a frequency selected at or below twice the frequency of the single-phase AC voltage as a cut-off frequency.

4. The power conversion device according to claim 2, wherein;

the second compensation means applies the low frequency cut-off processing using a frequency selected at or below twice the frequency of the single-phase AC voltage as a cut-off frequency.

5. The power conversion device according to claim 1, wherein;

the voltage command value generation unit performs one-pulse control by which the voltage command value is outputted by performing upper limit value setting processing on an amplitude value of a voltage to be applied to the motor.

6. The power conversion device according to claim 2, wherein;

the voltage command value generation unit performs one-pulse control by which the voltage command value is outputted by performing upper limit value setting processing on an amplitude value of a voltage to be applied to the motor.

7. The power conversion device according to claim 1, wherein;

the motor that feeds power is a totally-enclosed type motor in which a rotor of the motor is cooled without depending on intake air from an outside.

8. The power conversion device according to claim 2, wherein;

the motor that feeds power is a totally-enclosed type motor in which a rotor of the motor is cooled without depending on intake air from an outside.