Chennai Metro Rail Ltd has awarded contract for power supply and Overhead Equipments (OHE) to Siemens AG of Germany and its Indian arm Seimens Ltd India Consortium for Rs 305 crore. The contract, awarded to the lowest bidder in an international bidding, includes design, supply, installation, testing and commissioning of complete power supply systems.
Three traction sub-stations would be set up under the contract to step-down the voltage from 110 kV to 25 kV AC single phase for use for the traction purposes, according to an announcement from CMRL. CMRL has selected 25 kV AC traction power for energy efficiency and safety. This would be supplied to train through OHE to be installed along the track.
CMRL would receive electrical power from Tamil Nadu Electricity Board for a maximum demand of 60 MVA from three 110 kV sub-stations being set up by Electricity Board at Koyambedu, Alandur and Chennai Central.
The contract includes setting up of three auxiliary sub-stations at Koyambedu, Alandur and Chennai Central to step down the 110 kV to 33 kV for supply of power to stations, air-conditioning systems, tunnel ventilation systems, lighting and other utilities at the stations. The sub-stations will be of gas insulated ones for higher reliability and maintenance-friendly.
The entire power supply system could be monitored and controlled through Supervisory Control and Data Acquisition system (SCADA). The remote operation would be managed from centralized operation control centre located at Koyambedu.
Besides setting up the facilities, the contract also includes provisions for comprehensive maintenance till end of defect liability period of two years after the completion of the project, added the company.