Single-phase　ground　faults　in　distribution　networks　can　lead　to　severe　safety　hazards,　such　as　electric　shocks　and　forest　fires.　Although　inverter-based　flexible　arc　suppression　devices(FASD)　can　effectively　mitigate　fault　currents,　their　control　systems　must　achieve　stable　tracking　of　target　reference　values　under　complex　and　variable　fault　conditions.　To　address　this　issue,　this　paper　establishes　an　equivalent　load　circuit　model　for　the　FASD　based　on　the　principles　of　flexible　arc　suppression.　The　impedance　characteristics　and　variation　patterns　of　the　equivalent　load　circuit　under　different　single-phase　ground　fault　conditions　are　analyzed　in　depth.　The　study　reveals　that　the　equivalent　load　impedance　of　the　FASD　is　influenced　by　the　combined　effects　of　line　impedance,　ground　capacitance,　and　transition　resistance,　exhibiting　inductive,　resistive,　or　capacitive　characteristics.　As　the　transition　resistance　increases,　the　impedance　characteristic　transitions　from　inductive　to　capacitive　and　remains　constant.　These　findings　provide　theoretical　support　for　the　design　of　control　strategies　and　parameter　optimization　of　FASD.　©　2025　IEEE.