Static and small signal analysis of a series-resonant converter operating above its resonant frequency

A study of static and dynamic characteristics of a series-resonant power converter incorporating dual thyristor switches is presented. In a series-resonant converter (SRC), the dual thyristor operates at a frequency above its resonant frequency and this operation is efficiently achieved because of negligible turn-on and turn-off losses even at high frequencies. After reviewing the characteristics of a dual thyristor, the authors plot normalized static characteristics that are useful in designing SRC incorporating dual thyristors. For small signal perturbations, Bode diagrams of the control to output voltage transfer function are obtained by calculation and compared with experimental measurements. The effects of large signal perturbation on the stability of the SRC are also presented.