Soft switched three-phase boost rectifiers and voltage source inverters

• US 5,633,793 A
• Filed: 01/23/1995
• Issued: 05/27/1997
• Est. Priority Date: 01/23/1995
• Status: Expired due to Fees

• Current Assignee: Virginia Tech Intellectual Properties, Inc. (Virginia Polytechnic Institute and State University)
• Original Assignee: The Center For Innovative Technology, Virginia Polytechnic Institute and State University, Virginia Tech Intellectual Properties, Inc. (Virginia Polytechnic Institute and State University)
• Inventors: Lee, Fred C., Jiang, Yimin
• Primary Examiner(s): NGUYEN, MATTHEW VAN
• Application Number:
  US08/376,365
• Time in Patent Office: 855 Days
• Field of Search: 363/17, 363/37, 363/97, 363/98, 363/125, 363/127, 363/131, 363/132
• US Class Current: 363/127
• CPC Class Codes: H02M 7/062 Avoiding or suppressing excessive transient voltages or currents
• CPC Class Codes: H02M 7/219 in a bridge configuration
• 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 7/5387 in a bridge configuration
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A boost rectifier is provided with an ultra high speed diode in its direct current rail to reduce diode reverse recovery loss with or without implementing a soft switching technique. Full zero-voltage-transition (ZVT) as well as zero-current-transition (ZCT) may also be achieved by adding a simple auxiliary network across the DC rail which operates only during the short turn-on transients of the bridge switches. Similarly, a simple, inexpensive auxiliary circuit can be added to the DC rail of a conventional voltage source inverter shown to implement both ZVT and ZCT.

Claims

1. A three-phase boost rectifier for converting a three-phase alternating current power supply to a direct current power supply, comprising:

a three-phase alternating current power input;

a switching bridge connected between said alternating power input and a direct current rail output, said switching bridge comprising a plurality of switches each having an anti-parallel diode associated therewith;

a direct current rail diode connecting said switching bridge and said direct current rail output, said direct current rail diode being faster than said anti-parallel diodes; and

an auxiliary circuit connected across said switching bridge for achieving zero-voltage-transition, said auxiliary circuit comprising;

a resonant inductor and an auxiliary diode connected in series across said direct current rail diode; and

an auxiliary switch having a first pole connected between said resonant inductor and said auxiliary diode and a second pole connected to ground.

2. A three-phase boost rectifier for convening a three-phase alternating current power supply to a direct current power supply, comprising:

a three-phase alternating current power input;

a switching bridge connected between said alternating power input and a direct current rail output, said switching bridge comprising a plurality of switches each having an anti-parallel diode associated therewith;

a direct current rail diode connecting said switching bridge and said direct current rail output, said direct current rail diode being faster than said anti-parallel diodes; and

an auxiliary circuit connected across said switching bridge for achieving zero-current-transition, said auxiliary circuit comprising;

a resonant capacitor, a resonant inductor and an auxiliary diode connected in series across said direct current rail diode; and

an auxiliary switch having a first pole connected between said resonant inductor and said auxiliary diode and a second pole connected to ground.

3. A zero-voltage-transition voltage source inverter for converting a direct current power supply to a three-phase alternating current output, comprising:

a direct current power input;

a switching bridge connected between said direct current power input and said three-phase alternating current output; and

an auxiliary circuit connected between said direct current power input and said switching bridge, said auxiliary circuit comprising;

a rail switch connected to a direct current rail of said direct current power input;

an auxiliary switch connected in series with a resonant inductor across said rail switch; and

an auxiliary diode connected at a first end between said auxiliary switch connected and said resonant inductor and at a second end to ground.

4. A zero-current-transition voltage source inverter for converting a direct current power supply to a three-phase alternating current output, comprising:

a direct current power input;

a switching bridge connected between said direct current power input and said three-phase alternating current output; and

an auxiliary circuit connected between said direct current power input and said switching bridge, said auxiliary circuit comprising;

a rail switch connected to the direct current rail of said direct current power input;

an auxiliary switch connected in series with a resonant inductor and a resonant capacitor across said rail switch; and

an auxiliary diode connected at a first end between said auxiliary switch connected and said resonant inductor and at a second end to ground.

5. A bi-directional zero-voltage-transition (ZVT) converter, comprising:

a direct current power terminal;

a switching bridge connected between said direct current power terminal and a three-phase alternating current terminal;

a rail switch connected to the direct current rail of said direct current power terminal;

an ultra fast diode connected in parallel with said rail switch; and

an auxiliary circuit connected between said direct current power terminal and said switching bridge, said auxiliary circuit comprising;

a first auxiliary switch and anti-parallel diode connected in series with a resonant inductor across said rail switch; and

an second auxiliary switch and anti-parallel diode connected at a first end between said first auxiliary switch and said resonant inductor and at a second end to ground, whereby when said rail switch and said first auxiliary switch are open, said converter is a boost rectifier, and if said second auxiliary switch is open, said converter is a voltage source inverter.

6. A bi-directional zero-current-transition (ZCT) converter, comprising:

a direct current power terminal;

a switching bridge connected between said direct current power terminal and a three-phase alternating current terminal;

a rail switch connected to the direct current rail of said direct current power terminal;

an ultra fast diode connected in parallel with said rail switch; and

an auxiliary circuit connected between said direct current power terminal and said switching bridge, said auxiliary circuit comprising;

a first auxiliary switch and anti-parallel diode connected in series with a resonant inductor and a resonant capacitor across said rail switch; and

an second auxiliary switch and anti-parallel diode connected at a first end between said first auxiliary switch and said resonant inductor and at a second end to ground, whereby when said rail switch and said first auxiliary switch are open, said converter is a boost rectifier and if said second auxiliary switch is open, said converter is a voltage source inverter.