Control method for direct power converter

Patent metadata

Field	Value
Publication number	US-2016248335-A1
Application number	US-201415027558-A
Country	US
Kind code	A1
Filing date	Oct 7, 2014
Priority date	Oct 7, 2013
Publication date	Aug 25, 2016
Grant date	—

Abstract

A converter performs full-wave rectification on a single-phase voltage, thus outputting a rectified voltage across DC power supply lines. An inverter receives the rectified voltage and then supplies a three-phase AC current to an inductive load. Between the DC power supply lines is connected a charge and discharge circuit. The charge and discharge circuit includes a buffer circuit and a boost circuit. The buffer circuit includes a series connection between a capacitor and a switch. The boost circuit, which may be configured by a boost chopper, includes a switch, a reactor and a diode. The charge and discharge circuit provides and receives part of pulsations of the power input to the converter between the DC power supply lines.

First claim

1 - 8 . (canceled)

9 . A method for controlling a direct power converter,
said direct power converter comprising: a first power supply line; a second power supply line which is applied with a potential lower than said first power supply line is applied; a converter including an input side connected with a single-phase AC power supply and an output side connected with said first power supply line and said second power supply line, and performing single-phase full-wave rectification; a charge and discharge circuit located between said first power supply line and said second power supply line; and an inverter that converts a DC voltage between said first power supply line and said second power supply line into an AC voltage, said charge and discharge circuit comprising a buffer circuit including a capacitor and a first switch connected in series with said capacitor at a side close to said first power supply line between said first power supply line and said second power supply line, and providing and receiving power between said first power supply line and said second power supply line, and a boost circuit that boosts a rectified voltage from said converter to charge said capacitor, said buffer circuit providing power to said first power supply line and said second power supply line in a first period in which a cosine value to a value of twice a phase angle of an AC waveform output from said single-phase AC power supply is positive when the AC waveform is regarded as a sine value of the phase angle, and receiving power from said first power supply line and said second power supply line in a second period in which said cosine value is negative, said method comprising steps of: rendering said first switch conductive at a discharge duty to discharge said capacitor in said first period, and is rendered non-conductive in said second period; rendering said converter conductive at a rectifying duty; and rendering both a sum, in said first period, of a product of said rectified voltage and said rectified duty and a product of a both-end voltage of said capacitor and said discharge duty and a product, in said second period, of said rectified voltage and said rectifying duty to take a product of a crest value of an AC voltage of said single-phase AC power supply, a first value, and a second value, wherein said first value is half a value obtained by subtracting, from one, a product of a positive constant less than one and said cosine value, and said second value is a value obtained by dividing a virtual crest value, which is √{square root over (2)}-times an effective value of a first current input to the converter by a second current input to said inverter.

10 . The method for controlling a direct power converter according to claim 9 ,
wherein said rectifying duty takes a smaller one of a product of said second value and an absolute value of said sine value and a value obtained by subtracting said discharge duty from one in said first period.

11 . The method for controlling a direct power converter according to claim 10 ,
wherein said rectifying duty takes a value obtained by dividing a product of said second value and said first value by said absolute value of said sine value in said second period.

12 . The method for controlling a direct power converter according to claim 10 ,
wherein in said second period, said rectifying duty takes a value one; and said second current takes a value obtained by dividing a product of said virtual crest value of said first current and said first value by said absolute value of said sine value.

13 . The method for controlling a direct power converter according to claim 12 ,
wherein said second current takes a value obtained by dividing a product of said virtual crest value of said first current and said first value by an absolute value of a cosine value of said phase angle in said first period.

14 . The method for controlling a direct power converter according to claim 9 ,
wherein a value of √{square root over (2)}-times an absolute value, which is taken by said first current at a boundary between said first period and said second period, is adopted as said virtual crest value of said first current.

15 . The method for controlling a direct power converter according to claim 10 ,
wherein a value of √{square root over (2)}-times an absolute value, which is taken by said first current at a boundary between said first period and said second period, is adopted as said virtual crest value of said first current.

16 . The method for controlling a direct power converter according to claim 11 ,
wherein a value of √{square root over (2)}-times an absolute value, which is taken by said first current at a boundary between said first period and said second period, is adopted as said virtual crest value of said first current.

17 . The method for controlling a direct power converter according to claim 12 ,
wherein a value of √{square root over (2)}-times an absolute value, which is taken by said first current at a boundary between said first period and said second period, is adopted as said virtual crest value of said first current.

18 . The method for controlling a direct power converter according to claim 13 ,
wherein a value of √{square root over (2)}-times an absolute value, which is taken by said first current at a boundary between said first period and said second period, is adopted as said virtual crest value of said first current.

19 . The method for controlling a direct power converter according to claim 9 , wherein
said boost circuit comprises:
a diode including a cathode and an anode that is connected between said first switch and said capacitor;
a reactor connected between said first power supply line and said anode, through which a current input to said boost circuit flows; and
a second switch connected between said second power supply line and said anode, and
said second switch of said boost circuit is controlled to control a current flowing through said reactor in said second period.

20 . The method for controlling a direct power converter according to claim 10 , wherein
said boost circuit comprises:
a diode including a cathode and an anode that is connected between said first switch and said capacitor;
a reactor connected between said first power supply line and said anode, through which a current input to said boost circuit flows; and
a second switch connected between said second power supply line and said anode, and
said second switch of said boost circuit is controlled to control a current flowing through said reactor in said second period.

21 . The method for controlling a direct power converter according to claim 11 , wherein
said boost circuit comprises:
a diode including a cathode and an anode that is connected between said first switch and said capacitor;
a reactor connected between said first power supply line and said anode, through which a current input to said boost circuit flows; and
a second switch connected between said second power supply line and said anode, and
said second switch of said boost circuit is controlled to control a current flowing through said reactor in said second period.

22 . The method for controlling a direct power converter according to claim 12 , wherein
said boost circuit comprises:
a diode including a cathode and an anode that is connected between said first switch and said capacitor;
a reactor connected between said first power supply line and said anode, through which a current input to said boost circuit flows; and
a second switch connected between said second power su

Assignees

• Daikin Ind Ltd

Inventors

• Sakakibara Kenichi

Classifications

• H02M1/08

  Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters · CPC title

• H02M5/40

  with intermediate conversion into DC · CPC title

• H02M1/14

  Arrangements for reducing ripples from DC input or output · CPC title

• H02M5/4585

  having a rectifier with controlled elements · CPC title

• H02M5/458 Primary

  using semiconductor devices only · CPC title