A general linear continuous model for design of power conditioning units at fixed and free running frequency

Abstract

A linear continuous low frequency small signal model, valid for all types of converters (boost,buck, buck boost), both in heavy and light modes, is presen ted in this paper. Its interesting characteristics are that it is valid for free running as well as for fixed frequency converters and that it allows easily to take into account both input and output filters.Thanks to its modularity and its simple general form, it gives a strong insight into the influence of various parameters, (such as input filters) on perfor mance dynamics and into the design of efficient control loops.Finally, a computer program, using state analysis, has been developed allowing the automatic performance analysis of complete controlled converters. 1.With this in mind, it appeared to the authors that it should be interesting to dispose of a method gathe ring, on a practical point of view, the advantages of the state approach (namely its generality, the possibi lity to deal in the same way of all types of converters, in heavy and light modes, the easy description of a complex graph in which the cell is imbedded...) and those of the block diagram methods with their physical significance.The "injected current methods" seem in the author^ opinion to be a significant step towards this objective.In Section 2, the principles of the method will be briefly recalled and it will be shown how the method can take into account both input and output filters. The general model thus obtained gives new insight onthe way an input filter might destabilize a cell.In Section 3, some particularities of the model, as given in Section 2, will be discussed. Attention will be focused on the precautions which are to be taken when using it on simulation purposes in account of its non minimality. A minimal model will then be derived.In Section 4, it will be shown, using graph theory and state representation, how the previous results can be used for a fully automatic analysis of complete controlled converters.

Analysis, Design, and Implementation of the AFZ Converter Applied to Photovoltaic Systems

“…Knowing the dynamic performances of the converter is essential for the compensator design, which is implemented in almost every converter. The AFZ converter small-signal model is obtained through the Absorbed and Injected Current Model, described in detail in [38]. With this modeling technique, the dynamic performances of the converter are obtained through their input and output currents, see Figure 20.…”

Analysis and Extension of the Canonical Model applied to DC-DC converters with Input Filter and Output Post-filter

“…Sin embargo, el circuito resultante del método SSA varía según el modo de conducción (modo de conducción continuo o discontinuo) y si la magnitud de control es el ciclo de trabajo o la frecuencia [92] y [93]. Por otro lado, el circuito resultante del método IAC es siempre el mismo independientemente del modo de conducción y de si la magnitud de control es el ciclo de trabajo o la frecuencia [59] y [94]. Además, el circuito resultante es válido para cualquier topología, ya que lo único que cambiaría son los 6 coeficientes característicos [95].…”

Analysis and implementation of the Buck-Boost Modified Series Forward converter applied to photovoltaic systems

“…Classic model techniques based on averaging, linearization and perturbation, have been employed to obtain the small signal model of the BBMSF converter in CCM [33] - [35], see Figure 13. From the small signal model of the BBMSF converter, the expression (31) can be obtained.…”