Peterson　coil　has　not　achieved　excellent　arc-suppression　performance　due　to　the　increased　harmonic　and　active　component　of　the　fault　current　with　the　expansion　and　development　of　distribution　networks.　To　address　the　problem,　a　flexible　arc-suppression　device　(FASD)　based　on　the　three-phase　cascaded　H-bridge　(CHB)　converter　has　been　proposed.　This　paper　presents　an　interconnection　strategy　for　the　FASD　in　order　to　further　improve　the　reliability　of　the　device.　When　the　FASD　is　under　abnormal　conditions　such　as　line　fault,　incorrect　fault-phase　selection　and　excessive　injection　current,　the　proposed　strategy　achieves　the　interconnection　of　CHB　converters　between　different　phases　to　guarantee　the　uninterruptable　operation　of　the　arc-suppression　function　of　the　FASD.　Simulation　results　are　illustrated　to　verify　the　feasibility　of　the　proposed　interconnection　strategy.　©　2018　IEEE