Railways to adopt ‘IGBT’ technology to regenerate electrical energy

Indian Railways is reaching a new milestone of approving green energy project in Mumbai. The Ministry of railways has decided to replace the existing Electrical Multiple Units (EMUs) with the new ones fitted with regenerative brakes by adopting three phase technology with Insulated Gate Bi-polar Transistor (IGBT) based system which are capable of regenerating 25 to 30 per cent of the energy used. Forty seven (12 car) rakes have been commissioned with regenerative braking system so far and 48 rakes are expected to be commissioned during 2009-10. The Designated National Authority (DNA) which is under Ministry of Environment & Forests has accorded host country approval for this project under Clean Development Mechanism (CDM) on 12th Jan, 2009. World Bank is working for registration of this project with United Nations Framework Convention on Climate Change (UNFCCC). 

The purpose of the project is to adopt 3 phase IGBT technology in Indian Railways for three phase EMUs in Mumbai suburban area of Western & Central Railways. These are the passenger trains which have the ability to draw electricity from the Over Head Equipment (OHE) and regenerate energy during braking. The regenerative braking feature essentially makes use of the kinetic energy that is normally lost upon braking, which can be up to 30% of one train energy requirement and converts it to reusable electrical energy, thus saving on the energy input required to operate other EMU trains running in the section. 

The regenerated electrical energy reduces the consumption of equivalent grid electrical energy required by the powering train, thereby conserving electrical energy and subsequently leading to reductions in Green House Gases (GHG). 

The project activity would result in reduced total energy consumption because of the adoption of three phase DC/AC IGBT technology with regenerative braking and result in availability of the additional power at the western grid level (Western and Central Railways in Mumbai) and will lead to power being available for other economic activity in the region. Reduced carbon dioxide emission will result in reduced global warming, a world wide concern.