This　paper　presents　an　hardware　design　solution　for　integrated　protection　of　distribution　systems　(Network　Protection　Unit)　by　combining　transient　polarity　comparison　technique,　which　is　based　on　the　detection　and　processing　of　fault　generated　transient　current　signals.　The　integrated　protection　relays　installed　at　each　substation　of　a　distribution　network　are　communicated　with　the　Network　Protection　Unit　through　specially　designed　Packet　Transport　Network　(PTN)　for　fast　and　reliable　transmission　of　transient　polarity　current　signals.　The　relay　detects　the　faulted　generated　super-imposed　current　signals.　The　transient　polarity　identification　algorithm　is　then　applied　to　the　super-imposed　signals　to　identify　the　polarity　of　the　signal　detected.　The　Network　Protection　Unit　can　collect　all　the　transient　polarity　current　signals　under　its　protection　area.　Then　The　direction　of　a　fault　is　determined　by　comparison　of　the　polarity　of　the　signals　derived　from　all　the　line　sections　connected　to　the　substation.　The　actual　faulted　section　is　identified　by　the　Network　Protection　Unit　through　comparing　the　directional　information　from　various　stations.　Simulation　results　presented　in　the　paper　demonstrate　the　feasibility　of　the　scheme.　©　2016　SERSC.