With　development　of　selective　protection　technology,　the　range　of　selective　protection　should　be　extended　from　power　supply　side　to　terminal　side.　Considering　the　limitations　of　short-circuit　selective　protection　in　low-voltage　system,　a　concept　for　a　multi-level　system　with　full　range　selective　and　coordinative　protection　technology　is　propound,　both　system　architecture　and　key　techniques　to　realize　above　concept　are　expound　as　well.　Based　on　a　practical　low-voltage　experimental　system,　a　single-phase　short-circuit　fault　model　is　established,　which　is　applied　to　analyze　short-circuit　current　waveforms　for　full　phase　angle　range　and　their　early　short-circuit　fault　detection　with　wavelet　transform(WT).　With　early　short-circuit　detection,　the　extreme　learning　machine(ELM)　is　brought　into　research　peak　prediction　method.　The　practical　system　simulation　and　experimental　results　verify　both　early　detection　and　current　peak　prediction　to　be　effective　for　a　low-voltage　short-circuit　fault,　which　lays　a　theoretical　foundation　for　a　new　selective　protection　technology.　©,　2014,　Chinese　Machine　Press.　All　right　reserved.