Commuter Rail AC Electrification Load-Flow Simulation Report - RTD
Commuter Rail AC Electrification Load-Flow Simulation Report - RTD
Commuter Rail AC Electrification Load-Flow Simulation Report - RTD
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
<strong>Commuter</strong> <strong>Rail</strong> <strong>AC</strong> <strong>Electrification</strong> <strong>Load</strong>-<strong>Flow</strong> <strong>Simulation</strong> <strong>Report</strong> Revision 1<br />
7.0 ELECTRICAL SYSTEM INPUT DATA<br />
Data used for the electric network simulations include the following:<br />
• Electrical network data including:<br />
o Equivalent impedance of the utility system at the point of common coupling, i.e. the<br />
substation traction power transformer connection point<br />
o Traction power substation transformer impedances<br />
o Autotransformer impedances<br />
o Impedances of the traction power distribution and return systems between substations,<br />
switching station, and paralleling stations.<br />
• Locations of substations, switching station, and paralleling stations.<br />
• Train timetable including departure location and departure time for each train.<br />
• Operating time data including the time of simulation start and finish, and the power<br />
simulation time interval.<br />
The following electrical parameters were required for the system simulation:<br />
Utility System Data. The utility supply points were assumed to be transmission lines operating<br />
at 115 kV transmission voltage. Preliminary Xcel information indicated 115 kV system fault level<br />
of approximately 34,000 A, which is equivalent to 6,910 MVA, three-phase. Adjusting for phaseto-phase<br />
connection yields a short circuit value of 6,910*2/(sqrt (3)) = 5,985 MVA or 59.85 p.u.<br />
phase-to-phase, resulting in utility system equivalent impedance of 1/59.85 = 0.0167 p. u.<br />
Transformer Reactances. The traction power transformer reactance was assumed 7% on own<br />
rating of 10 MVA and autotransformer reactance was assumed 1.5% on own rating of 2 MVA.<br />
Traction Power Distribution and Return System Resistances and Reactances. The distribution<br />
and return system impedances were calculated for one mile length of one-track and twotrack<br />
electrified railroad segments, using the Alternative Transient Program (ATP) and Math-<br />
CAD 2000 Professional software 9 . The calculation resulted in the following resistance and reactance<br />
values.<br />
Table 8 -<br />
Distribution System Impedances – Autotransformer-Fed System<br />
Number<br />
of<br />
Tracks<br />
Feeder Resistance<br />
(Ohm/mile)<br />
Feeder Reactance<br />
(Ohm/mile)<br />
Catenary Resistance<br />
(Ohm/mile)<br />
Catenary Reactance<br />
(Ohm/mile)<br />
1 0.270 1.229 0.244 0.860<br />
2 0.311 1.356 0.248 1.024<br />
9 T. Kneschke, P. Mbika, Determination of Traction Power Distribution System Impedances<br />
and Susceptances for <strong>AC</strong> <strong>Rail</strong>road <strong>Electrification</strong> Systems, Proceedings of the 2004<br />
ASME/IEEE Joint <strong>Rail</strong>road Conference, April 6-8, Baltimore, MD. Paper No. <strong>RTD</strong>2004-66011.<br />
02/27/2009 FRSC Page 21 of 250