Abstract:
An electrified railway network is one of the solutions for Colombo traffic congestion
due to high population density and high daily passenger flow into the city from the
suburbs. Although the initial cost of a railway electrification project is higher
compared with other alternatives such as improvements to bus transport, energy,
maintenance and operational costs can be lower if the system is designed, maintained
effectively and used efficiently. System failures or, delays in system operations should
be minimized to reduce the time wasted in traveling.
Reliability and punctuality are the major factors to attract more passengers to use
public electrified transport facilities for their daily travel. Power supply is a critical
factor to maintain a higher reliability in an electrified railway system.
Designs to upgrade the 230 km long Colombo suburban railway network commenced
in 2017 and currently in progress in four stages. Different options for the power supply
configuration and the back-up power systems have been identified, qualitatively
evaluated and then recommended for implementation. A quantified reliability
assessment has not been reported in the design.
A standardized procedure and a reliability assessment model would be required to
evaluate the reliability of each optional configuration to supply power and backup
power. In this research, optional configurations to supply power to the future
electrified railway system of the Colombo Suburban Railway Project area were
developed. Reliability assessment was conducted for each optional configuration using
the models developed and simulated using Monte Carlo simulation technique.
Reliability worth analysis was done to weigh the costs and benefits of configurations
with higher reliability.
The model developed can be used for reliability assessment of the power supply to any
suburban electrified railway system in Sri Lanka.
