PWM-switch Model of Tapped Inductor Converters under Hysteretic Current-mode Control

In this paper, a small signal analysis for tapped inductor converter under the critical conduction mode control (CRM) is presented. Critical conduction mode control is one of the hysteretic current mode controls in variable switching frequency operation. In first, a mathematically-described variable-frequency control modeling method for tapped inductor converters is introduced through extending the state-space averaging approach. Based on the results of the method, a newly-developed PWM-switch small-signal model for CRM control method is derived, which provides a physically-intuitive circuit model. The model greatly reduces the efforts in analyzing complex converters such as the tapped inductor converters. In order to verify those models, experimental results of a tapped inductor converter are presented. The general converter model parameters are summarized in the conclusion as well