| Abstract |
Most analyses of quasi-resonant DC/DC converter operate adopt some simplifying hypothesis, and ignore the parasitic resistors of the conductors or the active and reactive components. They also assume that there is a free wheeling phase, which limits the validity of the analysis. This raises the problem of running without load or with a low load. We have analysed the operation of a quasi-resonant converter disregarding the free wheeling phase to determine if it will run without load and the effect on its control. Transient cycles are shown to occur and all the limit running modes are determined by exhaustive analysis. Simulations show that there are transient limit running modes during rapid changes in the operating frequency. A 50 W, 100 kHz zero current quasi-resonant converter was built to check the findings. |
