Dual　active　bridge　(DAB)　converter　technologies　are　advanced　DC/DC　converter　topologies　widely　adopted　in　solid-state　transformers,　DC　microgrids,　and　other　applications.　However,　the　traditional　design　employs　the　conventional　single-phase-shift　(SPS)　modulation　that　brings　problems　such　as　increased　backflow　power,　rising　current　stress,　and　reduced　efficiency　when　the　voltage　ratio　deviates　from　one.　Improved　symmetry　and　asymmetry　modulations　have　been　proposed　to　solve　these　issues.　This　paper　investigates　the　effects　of　dual-phase-shift　(DPS)　and　unilateral　asymmetric　PWM　modulation　(UAPM)　on　the　peak-to-peak　current　and　zero　voltage　switching　(ZVS)　for　DAB　converters.　The　mathematical　models　of　transmission　power,　peak-to-peak　current,　and　ZVS　ability　of　SPS,　DPS,　and　UAPM　were　derived　through　detailed　analysis　of　their　operations.　In　addition,　the　optimization　strategies　and　benefits　achieved　by　DPS　and　UAPM　through　KKT　conditions　were　compared.　It　was　found　that　both　DPS　and　UAPM　significantly　optimized　the　performance　of　peak-to-peak　current　and　ZVS　ability,　where　UAPM　exhibited　good　performance　under　high　voltage　ratio　and　light　load.　©　2024　IEEE.