Three level inverter apparatus

• US 6,307,760 B1
• Filed: 09/01/2000
• Issued: 10/23/2001
• Est. Priority Date: 02/25/2000
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ikimi, Takashi
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): Laxton, Gary L.
• Application Number:
  US09/653,064
• Time in Patent Office: 417 Days
• Field of Search: 363/34, 363/35, 363/37, 363/39, 363/47
• US Class Current: 363/39
• CPC Class Codes: H02M 5/4585 having a rectifier with controlled elements
• CPC Class Codes: H02M 7/527 by pulse width modulation
• CPC Class Codes: H02P 27/14 with three or more levels of voltage
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

A three level inverter apparatus for suppressing a resonance current flowing therethrough, to thus improve its conversion efficiency and operational stability. This inverter apparatus includes a converter 1 for converting AC power source power to DC power, an inverter for converting thus converted DC power to AC power, and a DC link for interconnecting these converter and inverter. This DC link has two first smoothing capacitors connected in series between a positive-polarity potential bus P and a negative-polarity potential bus N for storing DC power obtained by the converter 1 and two second smoothing capacitors connected in series between the positive-polarity potential bus P and the negative-polarity potential bus N for storing DC power to be supplied to the inverter. The positive-polarity and negative-polarity potential buses each have a resonance-suppressing reactor inserted therein and the intermediate-potential bus, a resonance-suppressing resistor inserted therein.

Claims

1. A three level inverter apparatus comprising:

a converter for converting AC power source power to DC power;

an inverter for converting the DC power to AC power; and

a DC link for interconnecting the converter and the inverter, wherein

the DC link has two first smoothing capacitors connected in series between a positive-polarity potential bus and a negative-polarity potential bus for storing DC power obtained by the converter and two second smoothing capacitors connected in series between the positive-polarity potential bus and the negative-polarity potential bus for storing DC power to be supplied to the inverter; and

an interconnection point between the two first smoothing capacitors and an interconnection point between the two second smoothing capacitors are interconnected by an intermediate-potential bus, the intermediate-potential bus having a resistor inserted therein for controlling resonance.

2. A three level inverter apparatus comprising:

a converter for converting AC power source power to DC power;

an inverter for converting the DC power to AC power; and

a DC link for interconnecting the converter and the inverter, wherein

the DC link has two first smoothing capacitors connected in series between a positive-polarity potential bus and a negative-polarity potential bus for storing DC power obtained by the converter and two second smoothing capacitors connected in series between the positive-polarity potential bus and the negative-polarity potential bus for storing DC power to be supplied to the inverter; and

an interconnection point between the two first smoothing capacitors and an interconnection point between the two second smoothing capacitors are interconnected by an intermediate-potential bus; and

the positive-polarity potential bus and the negative-polarity potential bus each have a reactor inserted therein for controlling resonance.