A comparative study of small-signal average models for average current mode control

This paper presents a critical evaluation of four small-signal average models for average current mode control. The four models are divided into two groups. One group includes sampling effect in the model formulation that has been used successfully for peak current mode control, and the other does not include it. The models are evaluated against experimental data generated by using a Buck converter as a common test bed under various converter circuit and operating parameter changes. For practical design purposes, results are interpreted and explained by employing a simplified version of the second group of models to reveal more insight into average current model control. The study finds similarities and differences among these models as well as their limitations in predicting small-signal dynamics of average-current-mode-controlled DC-DC converters.

[1]  P. Cooke,et al.  Modeling average current mode control [of power convertors] , 2000, APEC 2000. Fifteenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.00CH37058).

[2]  Kai Zenger,et al.  Dynamic effects of inductor current ripple in peak-current and average-current mode control , 2001, IECON'01. 27th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.37243).

[3]  Ruqi Li,et al.  A unified small signal analysis of DC-DC converters with Average Current Mode Control , 2009, 2009 IEEE Energy Conversion Congress and Exposition.

[4]  Ruqi Li,et al.  Effects of circuit and operating parameters on the small-signal dynamics of average-current-mode-controlled DC-DC converters , 2011, 8th International Conference on Power Electronics - ECCE Asia.

[5]  Jian Sun,et al.  Modeling and practical design issues for average current control , 1999, APEC '99. Fourteenth Annual Applied Power Electronics Conference and Exposition. 1999 Conference Proceedings (Cat. No.99CH36285).

[6]  Ruqi Li Modeling Average-Current-Mode-Controlled multi-phase buck converters , 2008, 2008 IEEE Power Electronics Specialists Conference.

[7]  K. Zenger,et al.  Dynamic effects of inductor current ripple in average current mode control of [DC/DC power converter] , 2001, 2001 IEEE 32nd Annual Power Electronics Specialists Conference (IEEE Cat. No.01CH37230).

[8]  R. B. Ridley,et al.  A new, continuous-time model for current-mode control (power convertors) , 1991 .

[9]  Fred C. Lee,et al.  Small-signal modeling of average current-mode control , 1993 .