Motor driving apparatus

• US 7,310,475 B2
• Filed: 03/31/2005
• Issued: 12/18/2007
• Est. Priority Date: 09/30/2004
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Okuda, Tatsuya, Urakabe, Takahiro, Kuramoto, Yuuji
• Primary Examiner(s): Donovan, Lincoln
• Assistant Examiner(s): SMITH, TYRONE W
• Application Number:
  US11/094,232
• Publication Number:
  US 20060067655A1
• Time in Patent Office: 992 Days
• Field of Search: 318/139, 318700-811, 388800-900
• US Class Current: 388/805
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/14 Arrangements for reducing ripples from dc input or output
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 7/53873 with digital control
• CPC Class Codes: Y10S 388/90 Specific system operational feature

Abstract

A motor driving apparatus is provided which can minimize ripple current flowing through a DC link capacitor, and downsize the motor driving apparatus. It synchronizes the frequency of the inverter carrier signal for driving an inverter with the frequency of the DC/DC converter carrier signal for driving a DC/DC converter, and carries out control in such a manner that the center of a period during which the input current of the inverter is zero and the center of a period during which the output current of the DC/DC converter is zero are matched.

Claims

1. A motor driving apparatus comprising:

a power supply;

a DC/DC converter connected to said power supply;

an inverter connected to said DC/DC converter;

a DC link capacitor connected between said inverter and said DC/DC converter for smoothing a voltage; and

a control circuit for controlling power supply from said DC/DC converter to said inverter in a manner that a period in which output current of said DC/DC converter becomes zero takes place in a period during which an input current to said inverter is zero,

wherein said inverter and said DC/DC converter are based on triangular wave comparing type PWM control;

said DC/DC converter is a 2-phase DC/DC converter having a first DC/DC converter and a second DC/DC converter, a carrier signal of said first DC/DC converter and a carrier signal of said second DC/DC converter having a phase difference of 180 degrees, and a boosting ratio command variable being less than two; and

said control circuit matches timing of peaks of a carrier signal of said inverter and timing of valleys of the carrier signal of said first DC/DC converter, and timing of valleys of the carrier signal of said inverter and timing of valleys of the carrier signal of said second DC/DC converter.

2. A motor driving apparatus comprising:

a power supply;

a DC/DC converter connected to said power supply;

an inverter connected to said DC/DC converter;

a DC link capacitor connected between said inverter and said DC/DC converter for smoothing a voltage; and

a control circuit for controlling power supply from said DC/DC converter to said inverter in a manner that a period in which output current of said DC/DC converter becomes zero takes place in a period during which an input current to said inverter is zero,

wherein

said inverter and said DC/DC converter are based on triangular wave comparing type PWM control;

said DC/DC converter is a 2-phase DC/DC converter having a first DC/DC converter and a second DC/DC converter, a carrier signal of said first DC/DC converter and a carrier signal of said second DC/DC converter having a phase difference of 180 degrees, and a boosting ratio command variable being equal to or greater than two; and

said control circuit matches timing of peaks and valleys of a carrier signal of said inverter and timing of midpoints between peaks and valleys of the carrier signals of said first DC/DC converter and of said second DC/DC converter.

3. A motor driving apparatus comprising:

a power supply;

a DC/DC converter connected to said power supply;

an inverter connected to said DC/DC converter;

a DC link capacitor connected between said inverter and said DC/DC converter for smoothing a voltage; and

a control circuit for controlling power supply from said DC/DC converter to said inverter in a manner that a period in which output pulse current of said DC/DC converter has a minimum amplitude takes place in a period during which an input pulse current to said inverter has a minimum amplitude,

wherein said control circuit synchronizes a frequency of an inverter carrier signal for driving said inverter and a frequency of a DC/DC converter carrier signal for driving said DC/DC converter,

wherein said DC/DC converter is a 2-phase DC/DC converter having two DC/DC converter units; and

said control circuit matches timing at which input current to said inverter becomes zero and timing at which output current of one of said DC/DC converter units becomes zero, and timing at which input current to said inverter becomes nonzero and timing at which output current of the other of said DC/DC converter units becomes nonzero.

4. A motor driving apparatus comprising:

a power supply;

a DC/DC converter connected to said power supply;

an inverter connected to said DC/DC converter;

a DC link capacitor connected between said inverter and said DC/DC converter for smoothing a voltage; and

a control circuit for controlling power supply from said DC/DC converter to said inverter in a manner that a period in which output pulse current of said DC/DC converter has a minimum amplitude takes place in a period during which an input pulse current to said inverter has a minimum amplitude,

wherein said control circuit synchronizes a frequency of an inverter carrier signal for driving said inverter and a frequency of a DC/DC converter carrier signal for driving said DC/DC converter,

wherein, said motor driving apparatus comprises a region in which said DC/DC converter carries out boosting operation and voltage reduction operation in a region in which a modulation factor of said inverter is 0.2-1.0.

5. A motor driving apparatus comprising:

a power supply;

a DC/DC converter connected to said power supply;

an inverter connected to said DC/DC converter;

a DC link capacitor connected between said inverter and said DC/DC converter for smoothing a voltage; and

a control circuit for controlling power supply from said DC/DC converter to said inverter in a manner that a period in which output current of said DC/DC converter becomes zero takes place in a period during which an input current to said inverter is zero,

wherein said inverter and said DC/DC converter are based on triangular wave comparing type PWM control;

said DC/DC converter is a 3-phase DC/DC converter having a first DC/DC converter, a second DC/DC converter and a third DC/DC converter, a carrier signal of said first DC/DC converter and a carrier signal of said second DC/DC converter having a phase difference of 120 degrees, the carrier signal of said second DC/DC converter and a carrier signal of said third DC/DC converter having a phase difference of 120 degrees, and a boosting ratio command variable being less than 1.5 or equal to greater than 3; and

said control circuit matches timing of peaks or valleys of a carrier signal of said inverter and timing of valleys of the carrier signal of one of said first to third DC/DC converters.

6. A motor driving apparatus comprising:

a power supply;

a DC/DC converter connected to said power supply;

an inverter connected to said DC/DC converter;

a DC link capacitor connected between said inverter and said DC/DC converter for smoothing a voltage; and

a control circuit for controlling power supply from said DC/DC converter to said inverter in a manner that a period in which output current of said DC/DC converter becomes zero takes place in a period during which an input current to said inverter is zero,

wherein said inverter and said DC/DC converter are based on triangular wave comparing type PWM control;

said DC/DC converter is a 3-phase DC/DC converter having a first DC/DC converter, a second DC/DC converter and a third DC/DC converter, a carrier signal of said first DC/DC converter and a carrier signal of said second DC/DC converter having a phase difference of 120 degrees, the carrier signal of said second DC/DC converter and a carrier signal of said third DC/DC converter having a phase difference of 120 degrees, and a boosting ratio command variable being equal to greater than 1.5 and less than 3; and

said control circuit matches timing of peaks or valleys of a carrier signal of said inverter and timing of peaks of the carrier signal of one of said first to third DC/DC converters.

7. A motor driving apparatus comprising:

a power supply;

a DC/DC converter connected to said power supply;

an inverter connected to said DC/DC converter;

a DC link capacitor connected between said inverter and said DC/DC converter for smoothing a voltage; and

a control circuit for controlling power supply from said DC/DC converter to said inverter in a manner that a period in which output pulse current of said DC/DC converter has a minimum amplitude takes place in a period during which an input pulse current to said inverter has a minimum amplitude,

wherein said control circuit synchronizes a frequency of an inverter carrier signal for driving said inverter and a frequency of a DC/DC converter carrier signal for driving said DC/DC converter,

wherein, said motor driving apparatus comprises a plurality of inverters,

wherein said DC link capacitor are connected between said plurality of inverters and said DC/DC converter, for smoothing the voltage, and

wherein said control circuit controls power supply from said DC/DC converter to said inverters in a manner that a period in which output current of said DC/DC converter becomes zero takes place in a period during which an input current to one of said plurality of inverters, which has greatest output power or output current, is zero.