Phase current detection method, inverter control method, motor control method and apparatus for carrying out these methods

• US 7,671,557 B2
• Filed: 03/25/2008
• Issued: 03/02/2010
• Est. Priority Date: 09/29/2001
• Status: Active Grant

• Current Assignee: Daikin Industries Ltd
• Original Assignee: Daikin Industries Ltd
• Inventors: Taniguchi, Tomoisa, Maeda, Toshiyuki
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US12/076,936
• Publication Number:
  US 20080180056A1
• Time in Patent Office: 707 Days
• Field of Search: 318/139, 318/801, 318/811, 318/432, 318/729, 318/803, 318/805, 307/102, 307/105, 363/41
• US Class Current: 318/729
• CPC Class Codes: H02M 1/0009 Devices or circuits for detecting current in a converter
• CPC Class Codes: H02M 7/53873 with digital control
• CPC Class Codes: H02M 7/53875 with analogue control of three-phase output
• CPC Class Codes: H02M 7/53876 based on synthesising a desired voltage vector via the selection of appropriate fundamental voltage vectors, and corresponding dwelling times
• CPC Class Codes: H02M 7/5395 by pulse-width modulation
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence
• CPC Class Codes: H02P 6/28 Arrangements for controlling current H02P6/10 takes precedence

Abstract

Apparatus and methods for phase current detection used for driving a motor by supplying outputs from a pulse width modulation (PWM) converter to the motor. One method presented provides detecting a DC link current and a vector pattern, determining whether a voltage vector lengths exceeds a predetermined value, and adjusting the voltage vector by adding a positive or reversed voltage based upon the above determination and an integrated error value.

Claims

1. A motor controlling method, comprising:

calculating a motor voltage from a DC link voltage and a gate pulse width;

detecting a phase current from a DC link current and a vector pattern, wherein the method lowers a power factor and raises an output voltage or an output current given to said motor when a rotation speed is lower or a load is lighter; and

driving the motor based on the detected phase current.

2. The motor controlling method as defined in claim 1, wherein

the method lowers the power factor and raises the output voltage or the output current when the rotation speed is lower or the load is lighter so as to make the phase current detection easier.

3. A motor controlling apparatus for driving a motor by supplying outputs from a PWM inverter to the motor comprising:

a current detection section for determining a DC link current; and

a DC link voltage controlling section, associated with the current detection section, wherein said DC link voltage controlling section lowers a power factor and raises an output voltage or an output current given to said motor when a rotation speed is lower or a load is lighter.

4. The motor controlling apparatus as defined in claim 3, wherein

said DC link voltage controlling section lowers the power factor and raises the output voltage or the output current when the rotation speed is lower or the load is lighter so as to make the phase current detection easier.