Steady-state analysis of a series resonant converter with modified PWM control

In this work, a modified pulse-width modulation (PWM) control is adapted for a series resonant converter (SRC). Steady-state analysis of the SRC working in discontinuous-current mode (DCM) is presented. It is found that with the modified PWM control the SRC is able to maintain soft-switching in a wide range of voltage gain and load level, which is advantageous over the conventional PWM control. Based on the analysis, a design example of a 100kHz, 120V input, 48V output 200W converter is presented. Computer simulation and experimental test are included for the purpose of validation.