Large signal modeling of quasi-resonant converters using regulated unified model

This paper analyzes the large signal model of quasi-resonant converters (QRCs) using a unified model. The internal resistance of each component in the basic quasi-resonant switch model (QBSW) is taken into consideration. The parameters can be predicted under varying supply voltage and load current. In other words, the variation of switching frequency, which is a controller parameter, can be determined while output voltage is kept regulating. It is useful for designing an adaptive feedback controller. The power dissipation is analyzed so that the efficiency of the QRSW can be estimated. Moreover, the conduction loss of each component can be found. The critical component in power dissipation is known and the maximum efficiency can be predicted.