Modelling of the PRC-LCC resonant topology with a capacitor as output filter using EDF

In this paper, the extended describing function (EDF) and the generalised averaging modelling techniques have been applied to a PRC-LCC resonant AC/DC power conversion topology with a capacitor as output filter. In this way, a mathematical large signal model has been obtained to describe the topology dynamic behaviour. This large signal model consists of a set of nonlinear differential equations which are solved numerically with the help of a computer. The resulting algorithm is faster than a straight PSpice simulation and free of convergence problems. From this dynamical model, a very simple steady state model has also been deduced. In the paper it is shown and particularised for the operation along the optimum switching tine. Finally, the accuracy of the presented models is verified with a wide set of experimental results.