Power converter

Patent metadata

Field	Value
Publication number	US-9837929-B2
Application number	US-201515510718-A
Country	US
Kind code	B2
Filing date	Sep 24, 2015
Priority date	Sep 25, 2014
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A discharge duty that is a duty at which a switch is conductive takes a value obtained by dividing a product of a crest value of a single-phase AC voltage and a square of a cosine value of a phase of the single-phase AC voltage by a both-end voltage across a capacitor. A sum of a product of a rectifying duty that is a duty at which a converter is conductive and a rectified voltage output from the converter and a product of the both-end voltage and the discharge duty varies in a period that is a half of the period of the single-phase AC voltage.

First claim

The invention claimed is:

1. A power converter comprising:
a DC link including a first power supply line and a second power supply line;
a converter that receives a single-phase AC voltage and outputs a pulsating power to said DC link;
an inverter that receives a power from said DC link and outputs an AC current; and
a power buffer circuit that receives a charge power from said DC link and outputs a discharge power to said DC link,
wherein
an input power input to said inverter takes a value obtained, from said DC link, by subtracting said charge power from a sum of said pulsating power and said discharge power,
said charge power takes a value that is a half of said pulsating power,
said discharge power takes a value obtained by adding said charge power to an AC component of said pulsating power,
said converter applies a rectified voltage obtained by full-wave rectifying said single-phase AC voltage to said DC link while setting said first power supply line to have a higher potential than said second power supply line,
said power buffer circuit includes
a discharge circuit including a capacitor and a switch connected in series to said capacitor adjacent to said first power supply line between said first power supply line and said second power supply line, and
a charge circuit that charges said capacitor,

a discharge duty that is a duty at which said switch is conductive takes a value obtained by dividing a product of a crest value of said single-phase AC voltage and a square of a cosine value of a phase of said single-phase AC voltage by a both-end voltage across said capacitor,
said converter is conductive at a rectifying duty, and
a DC voltage that is a sum of a product of said rectified voltage and said rectifying duty and a product of said both-end voltage and said discharge duty varies in a period that is a half of a period of said single-phase AC voltage.

2. The power converter according to claim 1 , wherein said rectifying duty takes any one smaller value of an absolute value of a sine value of said phase and a value obtained by subtracting said discharge duty from 1.

3. The power converter according to claim 1 , wherein said rectifying duty takes a value obtained by subtracting said discharge duty from 1.

4. The power converter according to claim 1 , wherein a ratio of said both-end voltage to said crest value is 1 or more and 1.2 or less.

5. The power converter according to claim 4 , wherein said DC voltage varies in a pair of sections that are not adjacent to each other among sections equally dividing said period of said single-phase AC voltage into four and is constant in the other pair of sections.

6. The power converter according to claim 4 , wherein said inverter performs DC-AC conversion with a minimum value of said DC voltage as an upper limit.

7. The power converter according to claim 4 , wherein said DC voltage varies with a quarter of said period of said single-phase AC voltage as a fundamental period.

8. The power converter according to claim 1 , wherein said DC voltage varies with a quarter of said period of said single-phase AC voltage as a fundamental period.

9. The power converter according to claim 1 , wherein said DC voltage varies in a pair of sections that are not adjacent to each other among sections equally dividing said period of said single-phase AC voltage into four and is constant in the other pair of sections.

10. The power converter according to claim 1 , wherein said inverter performs DC-AC conversion with a minimum value of said DC voltage as an upper limit.

Assignees

• Daikin Ind Ltd

Inventors

• Sakakibara Kenichi

Classifications

• H02M7/48 Primary

  using discharge tubes with control electrode or semiconductor devices with control electrode · CPC title

• F03G7/08

  recovering energy derived from swinging, rolling, pitching or like movements, e.g. from the vibrations of a machine · CPC title

• H02M1/4225

  using a non-isolated boost converter · CPC title

• H02J3/36

  Arrangements for transfer of electric power between AC networks via high-voltage DC [HVDC] links; Arrangements for transfer of electric power between generators and networks via HVDC links · CPC title

• H02M5/458

  using semiconductor devices only · CPC title