简介：NorthwestElectricPowerDesignInstitute(NWEPDI)wasestablishedin1956.Theinstituteundertakestheengineeringexploration,surveyanddesignofthermalelectricpowerplant,conventionalislandofnuclearpowerplant,powertransmissionandsubstationprojects,designofthe1stand2ndclasspressurevessels,electricpowersystemplanning,environmentalprotectionengineeringmonitoring,assessmentanddesign,variousindustrialandcivilarchitecturaldesignandthescicntificresearchandtechnicaldevelopmenttasksofcorrespondingspecialities.Theinstituteis

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简介：IntroductionBeingofgreatvaluetorailwaytransportandhencetonationaleconomy,electrificationofrailwayshasbeencarriedoutveryrapidlyinChinainthepast30years.Bytheendof1990,some6941kmofelectrifiedrailwayshavebeenopenedtotrafficandabout16,000kmoronefourthofthetotalrailwaylengthareexpectedtobeelectrified,accountingfor45%ofthetotalrailwayfreightvolume.Atpresent,ShaanxiProvinceranksfirstwithrespecttototal