Review and trends in regenerative braking energy recovery for traction power system with inverter substation in subway’s of São Paulo city

Energy and environmental sustainability in transportation are becoming ever more important. In Brazil, the system electric traction represents the largest consumption of electric energy in the subway system. Electrified railway systems play an important role in contributing to the reduction of energy usage and CO2 emissions compared with other transport modes. For subway transit systems with frequently cycles of departures and braking of trains, the effective use of regenerative braking energy is a significant way to reduce the net energy consumption. The recovery of regenerative energy produced by braking trains of a subway system is essential to increase its energy efficiency, however difficult to apply in the São Paulo subway due to the short headway between train. This paper proposes evaluate through traction power network modeling and the computer simulation the application and feasibility of using inverter substation (ISS) to maximize the recovery of regenerative braking energy. The results of the study of Line 1 - Blue of the São Paulo’s metro city indicate that using inverter substation could reduce the energy consumption at the rectifier substation (RSS) by nearly 12,94% compared to the system without the inverter substation.