Multi-resonant LCC converter - comparison of different methods for the steady-state analysis

Several different approaches for the investigation of the steady-state properties of resonant converters have been published. In addition to solving the occurring equations in the time domain, which turns out to be quite cumbersome, the designer can make use of approximate approaches in the frequency domain. Two of these methods are compared to the exact solution with regard to their accuracy and mathematical complexity within this paper for the multi-resonant LCC converter with inductive output filter. Additionally, a minimized set of nonlinear equations is derived in case of the exact solution based upon the state-plane technique.