1. Stage 1 – CBD and Sports Precinct Traction Power System Analysis for Commonwealth Games

2. Background data to Stage 1
Combined team of Yarra and Arup engineers
Commenced November 2004
Model simulations commenced beginning April 2005
Pass Assets used in building the model
Simulation tests devised by Yarra Trams
Simulate worst case running conditions for the Games
Ongoing dialogue between Yarra and Arup to resolve data supply problems

3. Project Objectives
Modelling and simulation of the tram operations in the Melbourne CBD and Sports Precinct
Assessment of existing traction power network
Recommend possible improvements and/or upgrades to allow a safe and reliable 2006 Commonwealth Games service

4. Scope of Work Undertaken by Arup
Gather System and Vehicle Data
Build Tram Movement Model
Build Traction Power Model
Model Power Under Normal and Failure Conditions
Carry Out Simulation Tests
Analyse Simulation Results
Identify Possible Power System Deficiencies
Report to Yarra Trams

5. Simulation Software
Traction power simulation consists of two functions:
Tram movement calculation (VISION)
Power network analysis (OSLO)
The linkage between these two functions forms the structure of traction power system simulation

6. VISION - Tram Movement Simulator
VISION stands for Visualisation and Interactive Simulation of Infrastructure and Operations on tram Networks
VISION can simulate Yarra’s extensive tram network including real time representation of tram services throughout the system

7. OSLO – Traction Power Simulator
OSLO stands for Overhead System LOading
The program was initially produced to predict the performance of an AC electrified system
The program has now been developed to predict the performance of a DC electrified system

8. Input Data Supplied by Yarra Trams
Substation Data
Traction Power Network Data
Tram Vehicle Data
Tram Stop and Timing Point Data
Track Infrastructure Data
Timetable Information
Simulation Scenarios

9. Typical Output Data From Model
Tram Pantograph Operating Voltages
Trolley Wire Current Ratings
Substation Equipment Ratings
Feeder Cable Current Ratings

10. Timetable Scheduled Daily Timetable Commonwealth Games Timetable
Modelled between 6:30am to 9:30am
310 trams enter the CBD and Sports Precinct
20 seconds dwell time at each tram stop
Commonwealth Games Timetable
325 trams enter the CBD and Sports Precinct
20 min. peak running period from 8:00am to 8:20am
90 seconds headways on Flinders St. and Clarendon St.
Modern low floor trams on routes 48, 70, 75, 112, and 96

11. Simulation Scenarios
Normal Power Scenario (all substations in service)
Power Failure Scenario
Rectifier unit at Crombie Lane substation out of service
Westgate Freeway substation out of service
Main feeder at Flinders Street tie substation out of service
Tram Entry Time Perturbation Approach
Used to simulate the real situation on the tram network
20% of trams enter the simulation on time
80% of trams enter the simulation 1 to 59 seconds late
Entry time perturbation can be changed

12. Simulation Results
Normal and Failure Scenarios for Scheduled Timetable and the Commonwealth Games Timetable
Data processed:
Substation Voltages
Substation Loadings
Feeder Cable Currents
Overhead Conductor Currents
Parallel Cable Currents
Tram Pantograph Voltages
Tram Power Loadings

13. Typical Graphical Outputs – Power Graphs
Scheduled Timetable
Games Timetable

14. Typical Graphical Outputs – Voltage Graphs
Scheduled Timetable
Games Timetable

15. Typical Graphical Outputs – Journey Log Graphs
Scheduled Timetable
Games Timetable

16. Simulation Results The analysis suggests:
The network may require some additional feeder and parallel cables to accommodate the Commonwealth Games timetable
Some adjustments to the tram headways may have to be made
Yarra Trams should consider converting the existing Flinders Street tie substation to a full substation at some point in the future to improve the power network reliability

17. Discussions With Yarra Trams
Simulation results have been presented to Yarra Trams
Discussions have been held with Yarra electrical and power engineers
Yarra engineers are happy with the model approach and with Arup’s recommendations
We need to run the latest version of the Commonwealth Games timetable
Confirm possible upgrades to the network