A simple time-domain simulation of quasi resonant converters

This contribution deals with time domain simulation of quasi resonant power converters carried out by means of an ad hoc developed program. Computations are done using the decoupling technique in order to reduce the problem complexity and computation time. Each converter cycle is subdivided into four subintervals for which analytical simplified solutions are known and used to determine the voltage and current evolutions. Three analytical solutions were used with different approximations, and results have been compared. This simulation method allows one to observe large signal dynamic behavior of QR converters (at cycle level), and to obtain an estimation of some important in-cycle parameters, as output ripple voltage and maximum device stresses. Program results have been compared with PSPICE simulations, with a good agreement and a simulation time two orders of magnitude shorter.