Arc　extinguishing　of　grounding　faults　is　difficult　for　neutral　non-effective　grounding　distribution　networks.　In　traditional　flexible　arc-suppression　method,　the　real-time　measured　source　voltage　is　used　to　calculate　the　compensation　current,　which　is　injected　by　single　active　converter　connected　to　the　neutral　point　in　distribution　networks　to　compensate　the　fault　current.　Whereas,　the　zigzag　transformer　and　the　boosting　transformer　are　used　for　converter　to　integrate　into　the　power　distribution　network　and　faulty　phase　detection　is　necessary.　In　order　to　improve　the　above　mentioned　way,　a　novel　method　for　earth-fault　separate-phase　flexible　arc-suppression　in　distribution　systems　based　on　three-phase　cascaded　H-bridge　converteris　proposed　in　this　paper.　The　three-phase　cascaded　H-bridge　converters　are　connected　to　the　distribution　networks　directly　inductance.　When　a　single-phase-to-ground　fault　occurred,　the　real-time　measured　phase　voltage　is　used　to　calculate　the　compensation　current.　Then,　the　compensation　current　is　injected　by　the　three-phase　cascaded　H-bridge　converter　without　the　zigzag　transformer　and　the　boosting　transformer.　Therefore,　the　voltage　of　the　fault　phase　is　controlled　to　be　zero　and　the　fault　arc　is　suppressed.　The　simulation　verifies　that　the　proposed　principle　is　able　to　compensate　the　fault　current　flexibly　and　effectively,　and　restrain　the　restriking　of　earth-fault　arc.　Furthermore,　faulty　phase　detection　is　unnecessary　for　single-phase　or　three-phase　cascaded　H-bridge　converter　to　suppress　the　fault　arc.　©　2016,　The　editorial　office　of　Transaction　of　China　Electrotechnical　Society.　All　right　reserved.