Novel zero-voltage switching techniques for pulse-width-modulated converters

Two new classes of soft switching pulse-width-modulated (PWM) converters, named zero-voltage-switched (ZVS) PWM converters and zero-voltage-transition (ZVT) PWM converters, are proposed. The proposed ZVS-PWM converters combine the merits of conventional PWM and ZVS-QRC techniques. They are capable of regulating the output for a wide load and input voltage range while maintaining constant-frequency operation. By employing a saturable inductor, the load range under which ZVS is maintained can be significantly extended without increasing the voltage stress of the power switch. The parasitic oscillations between the diode junction capacitance and the resonant inductor are also significantly reduced. In the new class of ZVT-PWM converters, both the power switch and the rectifier diode are operated with zero-voltage switching, and are subjected to low voltage and current stresses associated with those in their PWM counterparts. Thus switching losses are significantly reduced at a slight increase in conduction losses. In addition, the circuit optimization is simplified because of constant-frequency operation. The operation principles of the proposed converters are described by using several examples. Several breadboarded converters are implemented to verify the theoretical analysis and to demonstrate the feasibility of the proposed technologies.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Electrical Engineering

Department dc:contributor.department

Electrical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1991

Author dc:creator

• Hua, Guichao

Chair dc:contributor.committeechair

• Lee, Fred C.

Committee members dc:contributor.committeemember

• Chen, Dan Y.
• Jovanovic, Milan M.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-03242009-040340

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/41743