The　active　distribution　networks　have　a　tendency　to　develop　toward　hybrid　ac-dc　systems　constructed　by　power　electronics,　the　magnitude　and　direction　of　power　may　change　randomly　at　any　time,　making　the　usual　protection　potentially　insensitive,　raising　the　negative　impacts　of　single-phase　ground　(SPG)　fault　which　accounts　for　the　majority　of　all　faults　that　occurred　in　medium-voltage　(MV)　distribution　networks　in　the　past.　The　zero-sequence　current　in　the　impedance　induced　between　the　lines　and　ground　will　pass　through　the　SPG　fault　branch　as　fault　current.　This　article　transfers　the　flow　path　of　the　zero-sequence　current　from　the　SPG　fault　branch　to　the　power　electronic　branch　connected　between　the　faulty　phase　and　ground　involved　in　the　construction　of　hybrid　ac-dc　system,　thereby　limiting　SPG　fault　branch　current　and　reducing　fault　node　potential.　This　helps　to　suppress　fault　arc　and　provides　engineers　with　safe　conditions　to　clear　faulty　elements　from　the　SPG　fault　branch.　The　power　electronic　carries　this　zero-sequence　current　instead　of　SPG　fault　branch　and　therefore　absorb　energy　from　the　distribution　networks　in　the　same　way　as　SPG　fault,　but　the　energy　is　not　lost　but　routed　back　to　the　hybrid　ac-dc　system　for　reuse.　Simulations　and　experiments　validate　the　proposal.　©　1986-2012　IEEE.