دانلود رایگان مقاله انگلیسی رویکرد مدل سازی یکپارچه برای مبدل های DC-DC بر اساس سلول سوئیچینگ - الزویر 2018

Abstract

This paper proposes a general small-signal model for the representation of dc-dc converters based on the three-state switching cell (3SSC) operating in continuous conduction mode (CCM). Even though such power electronic converters present distinct behaviors depending on the duty cycle range i.e. 0 < D < 0.5 and 0.5 < D < 1, the developed analysis effectively shows that the derived model is valid in either case. An approach similar to the PWM (pulse width modulation) switch is employed, being this a fair, simple, and straightforward technique if compared with other similar ones e.g. average state-space modeling. Dc and ac small-signal models can then be obtained in order to provide relevant expressions associated to the converters e.g. the static gain and several transfer functions used in the implementation of closed-loop control. A dc-dc buck converter is also investigated, whose model is properly represented by mathematical expressions that are validated by simulation tests for both operating conditions of the 3SSC.

V. CONCLUSION

The small-signal modeling approach proposed for dc-dc converters based on the 3SSC in CCM has proven to be a simple and straightforward technique, considering that the analysis is strictly carried out from the point of view of electric circuits. It has been show that it is able to represent the topologies operating in both operating modes i.e. NOM and OM, which can be typically found in 3SSC-based structures. A 3SSC dc-dc buck converter has been analyzed in detail, whose model has been properly validated comparing the Bode plots of the theoretical model with the ones obtained by simulation. It is worth to mention that the derived transfer functions are strictly important for the closed-loop operation of the converters. Besides, it has been proven that the resulting expressions are exactly the same ones valid for the conventional buck converter operating in CCM. Finally, it can be stated that the aforementioned modeling technique can easily be extended to other 3SSC converters, thus allowing the development of their respective small-signal models with few mathematical manipulations if compared to the average state-space technique.