Electrical SystemsElectrical Engineering in RailwaysRolling StockCommunications & ControlSignallingLV Installations in Stations and BuildingsElectrical Systems

Electrical Systems

Electrical SystemsHigh Voltage Aerial Lines and Underground CablesSubstations1500V dc Traction SystemOverhead WiringTraction ReturnPower Supply for signalling operation, communication equipment, station and buildings, etcLV installations in Railway Tunnels and Yards

Electrical SystemsStatutory EnvironmentRail Safety Act 2002Electricity Supply Act 1995Electricity Supply (Safety & Network Management) Regulation 2002

RailCorp is one of the Electricity Distributors in NSW

High Voltage A.C. Distribution SystemStandard Voltages11kV33kV66kV132kVModes of transferOverhead Transmission LinesUnderground Cable

HV Aerial LinesConductorsCopper Aluminium (AAC or Aluminium Alloy)Conductor SupportsWood PolesSteel Poles

HV CablesConductorsCopperConstructionPaper insulated lead sheathedXLPEConfigurationUndergroundGalvanised Steel Troughing / Ground Line Troughing

1500V D.C. SystemElectric Trains in NSW Run on 1500V D.C. Power is supplied from traction substations to trains by means of the overhead wiring (OHW) systemTrains collect current through pantographs sliding under the contact wireCurrent returns to the substations via traction rails

Traction SubstationsSwitchgearAC Circuit BreakerDC Circuit BreakerTransformers & RectifiersConvert the high voltage ac supply to 1500V dcControl and MonitoringSCADA (Supervisory Control and Data Acquisition)

Traction SubstationsSubstation SpacingTypically 4km to 15kmDepends on a number of factors includingTrain loadsTrack gradesLossesOHW typesTrain headwaysElectrolysis

Overhead Wiring (OHW)Overhead Wiring Systems in RailCorpSimple CatenaryOne or two contact wires supported by a catenary wireCompound CatenaryA main catenary supports an auxiliary catenary, which in turn supports the contact wireContact Only

Overhead WiringTensioning ModesFixed AnchoredWires rigidly anchored at both ends of the wire runTension in the wire varies with temperatureWire sags down at high temperaturesRegulated TensionTension is the wire is held approximately constant

Overhead Wiring (OHW)

Overhead Wiring (OHW)

Overhead Wiring

Power SuppliesSupplied from High Voltage Distribution SystemGenerally from the 11kV NetworkTransform voltage to 415V or 240VSignalling SuppliesGenerally two independent source of supplies are providedNormal supply from RailCorp HV Distribution SystemStandby supply from local electricity distributorPower supplies to stations, buildings, workshops and other LV installations.

Electrical SystemsChallengesReliabilityOn Time RunningSingle Contingency (Except for OHW)Double or Triple Contingency at Critical LocationsDesign to minimise restoration time after failuresSafetyStatutory ClearancesPermit SystemSafety in Design