Static Characteristics of Zero-Current-Switching Quasi-Resonant Buck Converter under Variation of Resonant Circuit and Load Parameters

The influence of resonant circuit parameters on static characteristics of a half-wave buck zero-current-switching quasi-resonant converter is investigated. The dependences of the maximum voltage conversion ratio under variation of resonant circuit time constant and characteristic impedance with different load impedance values are obtained by dint of multi-factor numeric simulation. The dependences of the ratio between the transistor current peak value and load impedance rms value under variation of resonant circuit time constant and characteristic impedance with different load impedance values are also obtained. Approximated equations for above dependencies are fitted. The research results allow determining the allowable limits of resonant inductance and capacitance values, as well as the load impedance to maintain the zero-current-switching mode.