High power factor operation of DCM series-parallel resonantconverter

This work presents the operating principle, analysis, design, simulation, and experimental results for a high frequency (HF) transformer isolated single stage ac-to-dc series-parallel resonant converter (SPRC) operating on the utility line, in discontinuous current mode (DCM). The equivalent circuit models and the state space analysis of the SPRC in DCM are presented. PROMATLAB software is used to solve the equations and to obtain important design parameters. SPICE3 simulation and experimental results obtained from a 150 W prototype are presented to verify the analysis. High power factor operation (>0.99) with low harmonic distortion (<18%) have been achieved for the entire load range even without active control, in addition to eliminating switching losses     

A fixed frequency LCL-Type series resonant converter

A fixed frequency LCL-type series resonant converter (SRC) which uses an inductive output filter is proposed. Steady-state analysis of the converter is presented using complex ac circuit analysis. Based on the analysis, a simple design procedure is given. Detailed space integrated control experiment (SPICE) simulation results are presented to evaluate the performance of the designed converter under varying load and supply voltage conditions. Also, detailed experimental results obtained from a metal-oxide-semiconductor field-effect transistor (MOSFET) based 500 W converter are presented to verify the analysis and SPICE simulation results. The results obtained from the analysis, SPICE simulation and the experimental converter are compared. The proposed converter requires a narrow variation in pulsewidth while maintaining lagging power factor mode of operation for a very wide variation in the load as well as supply voltage