Title :
Describing functions of power electronics circuits using progressive analysis of circuit waveforms
Author :
Chung, Henry S -H ; Ionovici, A. ; Zhang, J.
Author_Institution :
Dept. of Electron. Eng., City Univ. of Hong Kong, Hong Kong
fDate :
7/1/2000 12:00:00 AM
Abstract :
This paper presents a technique for calculating the AC line-to-output and control-to-output transfer characteristics of DC/DC converters, in which the time instants switching from one topology to the next one are a priori unknown and are determined by threshold conditions (i.e., by the time evolution of the converter waveforms). Describing functions are defined for small perturbations in either the input voltage or the control signal. After injecting a sinusoidal perturbation at the frequency of interest into the converter, the fundamental component of the output spectrum is determined. The describing functions are thus evaluated and provide the required AC transfer characteristics. The proposed method is integrated with a previously developed time-domain simulation algorithm, which is based on monitoring the switches positions, allowing the simulator to find automatically the switching instants and topological sequence of operation. Different examples are illustrated, including a classical pulse-width-modulated (PWM) converter, a current-programmed PWM regulator, and a switched-capacitor converter. The simulated results are compared with the experimental measurements and the results in the available literature
Keywords :
DC-DC power convertors; PWM power convertors; circuit simulation; describing functions; power electronics; switched capacitor networks; switching circuits; time-domain analysis; transfer functions; AC line-to-output transfer characteristics; DC/DC converters; PWM converter; SC converter; circuit waveforms; control-to-output transfer characteristics; current-programmed PWM regulator; describing functions; power electronics circuits; progressive analysis; pulse-width-modulated converter; sinusoidal perturbation injection; switched-capacitor converter; threshold conditions; time instants switching; time-domain simulation algorithm; Analog-digital conversion; Circuit topology; DC-DC power converters; Frequency conversion; Power electronics; Pulse width modulation; Pulse width modulation converters; Switching converters; Time domain analysis; Voltage control;
Journal_Title :
Circuits and Systems I: Fundamental Theory and Applications, IEEE Transactions on