High frequency is an effective means to improve power density of power electronic devices

but it will increase switching losses of power electronic devices. Passive lossless soft-switching can effectively reduce switch loss of power electronic switch device. Three kinds of mainstream passive lossless soft-switching Buck converters

including minimum voltage stress（ MVS） lossless passive soft-switching circuit

the non-minimum voltage stress（ NMVS） passive lossless soft-switching circuit and minimum voltage and current stress（ MVCS） passive lossless soft-switching circuit are studied. The comparative study is carried out from aspects of topology structure

duty cycle

voltage and current stress

switching losses and efficiency of conversion. A hardware experimental environment is built

through

theoretical analysis and experimental verification show that the MVCS soft-switching circuit has better performance

which provides design basis for application of passive lossless soft-switching circuit.