Simplified analysis of PWM converters using model of PWM switch. II. Discontinuous conduction mode

Author

Vorpérian, Vatché

Author_Institution

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

Volume

26

Issue

3

fYear

1990

fDate

5/1/1990 12:00:00 AM

Firstpage

497

Lastpage

505

Abstract

For pt.I see ibid., vol.26, no.3, p.490-6 (1990). According to the method of state-space averaging, when a pulsewidth modulation (PWM) converter enters discontinuous conduction mode (DCM), the inductor current state is lost from the average model of the converter. It is shown that there is neither theoretical nor experimental justification for the disappearance of the inductor state as claimed by the method of state-space averaging. For example, when the model of the PWM switch in DCM is substituted in the buck, boost, or buck-boost converter while the inductor is left intact, the average model has two poles: the first pole f_p1 agrees with the single pole of state-space averaging, while the second pole f_p2 occurs in the range f_p2⩾F_s/π. It is shown that the right-half plane zeros present in the control-to-output transfer functions of the boost, buck-boost, and Cuk converters in continuous conduction mode are also present in discontinuous conduction mode

Keywords

network analysis; power convertors; pulse width modulation; switching circuits; Cuk converters; PWM converters; PWM switch; average model; buck-boost converter; control-to-output transfer functions; discontinuous conduction mode; inductor current state; right-half plane zeros; state-space averaging; Inductors; Power supplies; Predictive models; Pulse width modulation; Pulse width modulation converters; Switches; Switching converters; Switching frequency; Transfer functions; Transient response;

fLanguage

English

Journal_Title

Aerospace and Electronic Systems, IEEE Transactions on

Publisher

ieee

ISSN

0018-9251

Type

jour

DOI

10.1109/7.106127

Filename

106127