Steady-state and dynamic analyses of high-order parallel resonant convertors

The steady-state and small-signal dynamic analyses of a four-element, high-order parallel resonant DC-DC convertor operating in the continuous-current conduction mode are presented. The analyses are based on the concepts of describing function and harmonic balance. Other lower-order parallel resonant DC-DC convertors are analysed using modified versions of the equations for the four-element convertor. For output voltage control based on variation of switching frequency, convertor characteristics are determined and in some cases are compared with experimental and simulation results. It is shown that this analysis approach does not only provide an accurate unifying technique for convertor steady-state and small-signal dynamic analyses and design, but can also be used for the prediction of the output filter ripple components