With　the　development　of　power　conversion　systems　or　bidirectional　grid-connected　inverters　characterized　by　high　DC　voltage,　high　efficiency,　and　high-power　density,　high-switching-frequency　SiC　power　switches　are　being　widely　used,　and　these　require　a　short　computational　time　of　control　algorithm.　Based　on　the　sector　judgment　of　a　space　voltage　vector　and　the　midpoint　potential　control　balancing　of　a　DC　bus,　an　improved　finite　control　set　method　prediction　control　(FCS-MPC)　method　was　proposed　for　a　T-type　three-level　PCS.　This　improved　FCS-MPC　first　judges　the　sector　of　the　space　voltage　vector　and　locates　the　position　of　the　corresponding　large　sector　according　to　phase　lock　information;　then,　it　analyzes　the　sampled　voltage　of　the　upper　and　lower　bus　capacitors　to　obtain　the　midpoint　potential　situation　and　selects　appropriate　small　vectors　based　on　the　midpoint　potential　situation.　This　simple　improved　strategy　can　reduce　the　computational　complexity　of　traditional　MPC　for　rolling　optimization,　resulting　in　a　reduction　in　the　vectors　from　27　to　8.　A　SiC-based　10　kW　bidirectional　PCS　prototype　verified　the　improved　FCS-MPC,　and　the　computational　time　was　reduced　about　by　56%　in　comparison　to　traditional　FCS-MPC.