Modeling of Power Electronic Systems Using Signal Flow Graphs

This paper presents a signal flow graph analysis of the power electronic systems. Due to circuit switching the power electronic systems becomes non-linear and it´s modeling plays an important role in the design-oriented analysis. The well-established modeling techniques present difficulty in the model formulation, particularly, while we apply for higher order converters. The main emphasis of this paper is to evolve a simplified modeling process, using a graphical technique, irrespective of the order of the power electronic system. To realize this objective the following stages are developed: (i) guidelines to generate the flow graphs, (ii) step-by-step process which simplifies the designer burden and avoids the redundant graphs, (iii) generalized graph formulation, (iv) steady-state, small and large-signal models deduction from the generalized graph, and (v) simplified method to find useful performance indices for the design-oriented analysis. To show the novelty of the proposed technique few complex converter systems (higher order converters, interleaved converters and coupled inductor converters) are considered and the simplicity of the technique in the final model formulations is demonstrated. Few experimental results are provided to show the validity of the proposed modeling method