Soft switched three-phase boost rectifiers and voltage source inverters
AssigneesCenter for Innovative Technology, Virginia Tech Intellectual Properties, Inc., Virginia Polytechnic Institute and State University
InventorsFred C. Lee, Yimin Jiang
Life of this patent
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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.
Claims6
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.
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.
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.
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.
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.
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.
Dependencies are inferred from the claim text.