Quasi-resonant PWM inverter

• US 5,572,418 A
• Filed: 08/23/1994
• Issued: 11/05/1996
• Est. Priority Date: 08/23/1993
• Status: Expired due to Fees

• Current Assignee: GS Yuasa Corporation
• Original Assignee: GS Yuasa Corporation
• Inventors: Sano, Shigeru, Kimura, Gunji, Toba, Akio, Shimizu, Toshihisa
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): Riley, Shawn
• Application Number:
  US08/294,398
• Time in Patent Office: 805 Days
• Field of Search: 363/97, 363/131, 363/132, 363/139, 363/135, 363/137
• US Class Current: 363/97
• CPC Class Codes: H02M 7/4811 having auxiliary actively switched resonant commutation circuits connected to intermediate DC voltage or between two push-pull branches
• CPC Class Codes: H02M 7/4826 operating from a resonant DC source, i.e. the DC input voltage varies periodically, e.g. resonant DC-link inverters
• CPC Class Codes: H02M 7/487 Neutral point clamped inverters

Abstract

A quasi-resonant PWM inverter performs stable resonant operation utilizing a simple control system and a highly efficient inverter operation. A first condenser is connected between a connecting point between first and second main switches and to the first side of the first main switch. A second condenser is connected between the connecting point and the second side of the second main switch. The respective first and second sides of the first main switch and second main switch are connected to a DC power source having a first dividing point for the first potential and a second dividing point for the second potential. A terminal of a first auxiliary switch is connected to the first dividing point; and a terminal of a second auxiliary switch is connected to the second dividing point. A reactor is connected between the connecting points of the first and second auxiliary switches and the first and second main switches.

Claims

1. A quasi-resonant PWM inverter comprising:

a first condensor having a first terminal connected to a connecting point between a first side of terminals of a first main switch and a second side of terminals of a second main switch, and a second terminal connected to a second side of terminals of said first main switch;

a second condensor connected between said connecting point and a first side of terminals of said second main switch;

a DC power source connected between the second side of terminals of said first main switch and the first side of terminals of said second main switch;

said DC power source having a first dividing point with a first potential and a second dividing point with a second potential;

a first auxiliary switch having first and second sides of which the second side is connected to said first dividing point;

a second auxiliary switch having first and second sides, said first side connected to said second dividing point; and

a reactor connected between a connecting point to connect the first side of terminals of said first auxiliary switch to the second side of terminals of said second auxiliary switch, and said connecting point to connect the first and second main switches.

2. A quasi-resonant PWM inverter comprising:

a first condensor having a terminal connected to a connecting point between a first side of terminals of a first main switch and to a second side of terminals of a second main switch, and a terminal connected to a second side of terminals of said first main switch;

a second condensor connected between said connecting point and a first side of terminals of said second main switch;

a DC power source connected between the second side of terminals of said first main switch and the first side of terminals of said second main switch, said DC power source having half-dividing points;

first and second auxiliary power sources connected to the half-dividing points for said DC power source to form a first potential point having a first potential and a second potential point having a second potential;

a first auxiliary switch having first and second sides the second of which is connected to said first potential point;

a second auxiliary switch having first and second sides and the first of which is connected to said second potential point; and

a reactor having a terminal connected to a connecting point between the first side of terminals of said first auxiliary switch to the second side of terminals of said second auxiliary switch, and another terminal connected to said connecting point between said first and second main switches.