Title page for ETD etd-03242009-040340


Type of Document Master's Thesis
Author Hua, Guichao
URN etd-03242009-040340
Title Novel zero-voltage switching techniques for pulse-width-modulated converters
Degree Master of Science
Department Electrical Engineering
Advisory Committee
Advisor Name Title
Lee, Fred C. Committee Chair
Chen, Dan Y. Committee Member
Jovanovic, Milan M. Committee Member
Keywords
  • Switched capacitor circuits
Date of Defense 1991-05-28
Availability restricted
Abstract
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.

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