The　Input-parallel-output-parallel　(IPOP)　dual-active-bridge　(DAB)　converter　is　a　popular　solution　to　be　used　as　a　solid-state-transformer　(SST)　to　increase　current　capacity　for　its　advantages　including　as　bidirectional　power　flow,　soft　switching,　and　high　efficiency.　To　reduce　circulating　and　turn-off　currents　under　single-phase-shift　(SPS)　control,　an　IPOP　DAB　converter　with　a　modulated　coupled　inductor　and　the　optimized　modulation　trajectory　are　proposed　in　this　paper.　Compared　with　the　previous　modulated　coupled　inductor　solutions,　the　phase-shift　angle　between　two　modules　is　controlled　by　PWM　signals　from　0°　to　180°,　instead　of　just　working　at　two　fixed　values　(0°　and　180°).　Based　on　the　derived　model　of　the　modulated　coupled　inductor　and　analysis　of　converter　working　modes,　the　relationship　between　the　two　phase-shift　angles　and　the　current　stress　of　the　converter　is　analyzed　in　depth.　Consequently,　an　optimized　modulation　trajectory　is　also　proposed　to　achieve　low　turn-off　current　and　RMS　current　for　IPOP　DAB　converters　used　for　SST　applications.　The　parameters　design,　including　leakage　inductance　and　coupling　coefficient,　is　introduced.　A　250kHZ,　400/400V,　2000W　IPOP　DAB　prototype　is　built　to　verify　the　effectiveness　of　the　proposed　solution.　IEEE