The Quantitative Characterization of Symbolic Series of a Boost Converter

In this letter, the authors put forward a symbolic approach to analyze the nonlinearities of switching power converters. This proposed method can be used to describe bifurcation and chaos behavior by means of coarse-grained symbols. First, the period-doubling structure of a symbolic series is studied in symbolic dynamics. Second, the block entropy, which is the related statistics of subsequences of a symbolic series, is introduced. Finally, two Boost converters are studied as examples to illustrate the applications of the proposed symbolic dynamics method. Via block entropy, both period-doubling and border collision bifurcations are identified and quantified, and initial value sensitivity is successfully used to distinguish chaos from periodic motions.