Multi-loop control for quasi-resonant converters

Author

Ridley, Raymond B. ; Tabisz, Wojciech A. ; Lee, Fred C Y ; Vorpérian, Vatché

Author_Institution

Dept. of Electr. Eng., Virginia Polytech. Inst. & State Univ., Blacksburg, VA, USA

Volume

6

Issue

1

fYear

1991

fDate

1/1/1991 12:00:00 AM

Firstpage

28

Lastpage

38

Abstract

A multiloop control scheme for quasi-resonant converters (QRCs) is described. Like current-mode control for pulse width modulation (PWM) converters, this control offers excellent transient response and replaces the voltage-controlled oscillator (VCO) with a simple comparator. In this method, referred to as current-sense frequency modulation (CSFM), a signal proportional to the output-inductor current is compared with an error voltage signal to modulate the switching frequency. The control can be applied to either zero-voltage-switched (ZVS) or zero-current-switched (ZCS) QRCs. Computer simulation is method applied to a ZCS buck QRC. A circuit implementation is presented that allows multiloop control to be used on circuits switching up to 10 MHz. This circuit requires few components and produces clean control waveforms. Experimental results are presented for zero-current flyback and zero-voltage buck QRCs, operating at up to 7 MHz. Good small-signal characteristics have been obtained

Keywords

power convertors; switching; transient response; 5 to 10 MHz; PWM; buck converters; circuit implementation; comparator; computer simulation; crossover frequency; current-mode control; current-sense frequency modulation; error voltage signal; multiloop control scheme; operational amplifier; output-inductor current; pulse width modulation; quasi-resonant converters; small-signal characteristics; switching frequency; transient response; voltage-controlled oscillator; zero-current flyback; zero-current-switched; zero-voltage-switched; Circuits; Computer errors; Frequency modulation; Pulse width modulation; Pulse width modulation converters; Switching frequency; Transient response; Voltage control; Voltage-controlled oscillators; Zero current switching;

fLanguage

English

Journal_Title

Power Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0885-8993

Type

jour

DOI

10.1109/63.65001

Filename

65001