I. A unified analysis of converters with resonant switches. II. Input-current shaping for single-phase ac-dc power converters

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5264182

Freeland, S D

Quasi-resonant converters are a family of single-switch resonant dc-dc converters featuring zero-current or zero-voltage switching. The topological structure uniting these resonant converters - and the rectangular-wave (PWM) converters on which they are based - leads to general models of their dc and low-frequency ac behavior. An expression is derived that yields the dc conversion ratio of a quasi-resonant converter in terms of the well-known conversion ratio of the underlying PWM topology. A small-signal, low-frequency dynamic model is developed whose parameters also incorporate the PWM conversion ratio. Input-current shaping, also shown as power-factor improvement, addresses the problem of improving input-current waveforms drawn by ac-dc converters. This thesis is restricted to single-phase ac-dc power-conversion systems. A set of rules is derived for determining whether a particular dc-dc converter topology is suitable for use as a current-shaping ac-dc converter. A new, low-cost converter is suggested that combines input-current shaping, isolation, and fast output-voltage regulation.

• Research Organization: California Inst. of Tech., Pasadena, CA (USA)
• OSTI ID: 5264182
• Country of Publication: United States
• Language: English

Related Subjects

24 POWER TRANSMISSION AND DISTRIBUTION
240100* -- Power Systems-- (1990-)
DC TO DC CONVERTERS
ELECTRICAL EQUIPMENT
ENERGY SYSTEMS
EQUIPMENT
FUNCTIONAL MODELS
POWER FACTOR
POWER SYSTEMS
RECTIFIERS
SWITCHES
VOLTAGE REGULATORS