(icrare 2023) analyzing energy efficiency improvement in dc-traction systems by using reversible substation

In recent years, with increasing popularity of using dc traction system in metro and urban railways, new challenges to find new methods for improving energy efficiency for dc traction systems have raised. some strategies focused on power quality to decrease the harmonic distortion level such as adding active power filter. the challenge in traction dc-systems would be increasing energy efficiency in metro when a great amount of lost energy in traction motors in the mode of braking. to overcome this challenge and to save energy, the regenerative energy of braking motors in trains (in the mode of generator) can be used for other trains in accelerating mode or it can be injected into the grid through a reversible substation. in this study, energy which can be gained from motors in mode of braking is simulated, then cost analysis and energy saving after using of regenerating power in traction system are implemented. the results have been analyzed and show favorable improvements in energy saving. shiraz metro line 2 is used for simulation model as a case study.