The Dhaka Metro Rail network, the country’s first, will be powered by electricity from the national grid. During emergencies, the metro trains are also equipped with high-capacity batteries to ensure that they keep running.
The project authority, the Dhaka Mass Transport Company Limited (DMTCL) said the metro rail employs the energy storage system, or ESS, which means the trains’ braking system will be used to recharge their batteries.
In case the power supply from the national grid is disrupted, the ESS will be activated to bring the metro trains to their nearest station.
The ESS is essentially a backup system that will be charged regularly through the train’s regenerative braking system.
Rasono Tetsuya, an official at Marubeni-L&T JV, which provided the electronic and mechanical systems for the metro rail, said the ESS was supplied by the Japanese company Toshiba. The supply of UPS (uninterrupted power source) comes from Fuji Electric.
“The ESS captures the kinetic energy from braking and can be reused by the train at different times. In this way, electricity will be saved on the one hand, while it can also be used to keep the trains running in case of an emergency.”
DMTCL will have two receiving sub-stations in the Uttara Depot and Motijheel areas to ensure an uninterrupted power supply to the metro rail network. Both receiving sub-stations will have one additional transformer as a backup.
This development needs to be seen in the context of recent power cuts in Bangladesh.
A failure in Bangladesh’s national power grid plunged much of the country into a blackout on Tuesday, officials said. Officials of the state-run Bangladesh Power Development Board said that power transmission failed somewhere in the eastern part of the country.