eeconomyandreliability.Thenbybuildingupthecalculationmodeofthenumberofoptimizationsubsectionitintroducesdifferentpowersupplyprojectsonthedifferentlinemodesinbrief.Third,,ordingbythecalculation.Thenitmakesanalysisanddiscussiononthenumberofoptimizationsubsection.Atlast,thearticlemakeconclusionontheeconomyandreliabilityofdifferentlinemodes,aswellas,itsapplicationsituation.Accordiontotheactualcircumstance,inallareasinfoshan.,reasonablelayout,qualifiedsafeandefficiently-.References[1]WenchengSu.Factoriespowersupply[M].MachineryIndustryPublishingHouse.1999.9[2]JiecaiLiu.Factoriespowersupplydesignguidance[M].MachineryIndustryPublishingHouse.1999.12[3]Powersupplyanddistributionsystemdesignspecifications[S].ChinaplansPress.1996[4]Low-voltagedistributiondesignspecifications[S].ChinaplansPress.1996.6