Generalisation of an averaged model approach to estimate the period-doubling bifurcation onset in power converters

摘要

The usual method of estimating the onset of bifurcation and studying non-linear phenomena in power electronic devices consists of defining the discrete-time model. This model provides more precise results than an averaged model. However, the discrete-time model cannot be developed easily for some particular systems. In this study, a continuous-time averaging model is developed for a boost converter in the continuous-conduction mode (CCM). This proposed model is used to obtain the eigenvalues of the system to predict the stable operation of the period-1 orbit. It is observed that the loss of the asymptotic stability of the proposed model corresponds to the onset of period-doubling bifurcation in the discrete-time model. The generalisation of this method is investigated by applying the proposed method to a DC active filter converter connected in parallel with a CCM boost converter. Using this model, it is possible to obtain the eigenvalues of the system to investigate robustness properties with regards to system parameter variations. To confirm the validity of the proposed method, simulation and experimental results are presented.