Power conversion device

Patent metadata

Field	Value
Publication number	US-2017149352-A1
Application number	US-201415129112-A
Country	US
Kind code	A1
Filing date	Jul 8, 2014
Priority date	Jul 8, 2014
Publication date	May 25, 2017
Grant date	—

Abstract

A power conversion device includes a rectifier circuit that converts an AC power from an AC power supply, into a DC power, a short-circuit unit that short-circuits the AC power supply via a reactor connected between the AC power supply and the rectifier circuit, a control unit that generates a plurality of drive signals to control the short-circuit unit in a half cycle of the AC power supply, and a smoothing capacitor. The control unit stepwise varies threshold values that limit a value of a power-supply current of the AC power supply, in an on-section or an off-section of the plurality of drive signals.

First claim

1 . A power conversion device comprising:
a rectifier circuit that converts an AC power from an AC power supply, into a DC power; processing circuitry that short-circuits the AC power supply via a reactor connected between the AC power supply and the rectifier circuit; and a controller that, in a half cycle of the AC power supply, stepwise varies threshold values that limit a value of a power-supply current of the AC power supply, generates a switching pulse that keeps the value of the power-supply current between the threshold values, and outputs the generated switching pulse as a drive signal for the processing circuitry.

2 . The power conversion device according to claim 1 , wherein the controller divides the switching pulse generated by the controller, into a plurality of switching pulses and outputs the switching pulses on a basis of the threshold values.

3 . The power conversion device according to claim 2 , wherein the controller varies the threshold values in an off-section of a switching pulse between one switching pulse and another switching pulse in the switching pulses.

4 . The power conversion device according to claim 3 , wherein the controller varies the threshold values in the on-section of a switching pulse generated after the off-section.

5 . The power conversion device according to claim 1 , wherein the controller varies the threshold values in each cycle of the AC power supply.

6 . The power conversion device according to claim 1 , wherein the controller varies the threshold values only when the AC power supply is positive or only when the AC power supply is negative.

7 . The power conversion device according to claim 1 , wherein a correspondence relationship between the switching pulse and the power-supply current is set in the controller, and
the controller controls the processing circuitry by using the correspondence relationship.

8 . The power conversion device according to claim 1 , wherein the controller controls the processing circuitry by using a power-supply current detected by a current detector provided outside the controller or the controller controls the processing circuitry by directly detecting the power-supply current without using the current detector.

Assignees

• Mitsubishi Electric Corp

Inventors

• Arisawa Koichi
• Yamakawa Takashi
• Takayama Yuji
• Shimomugi Takuya
• Shinomoto Yosuke

Classifications

• H02M2001/0009

  Electricity · mapped topic

• H02M1/42

  Circuits or arrangements for compensating for or adjusting power factor in converters or inverters · CPC title

• H02M1/12

  Arrangements for reducing harmonics from AC input or output · CPC title

• H02M1/08

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

• H02M7/06 Primary

  using discharge tubes without control electrode or semiconductor devices without control electrode · CPC title