Chennai Metro has signed ABB, a global technology company, for providing active front end variable speed drives (VSDs) for the ventilation system of Chennai Metro line. The new 9 km long extension line plies from the northern part of the city to Chennai International Airport in the south. ABB solutions are part of this metro system with the supply of ACH580 and ACS880 active front end drives to support the metro line’s ventilation system and platform cooling. ABB India has partnered with Sterling Wilson, an EPC company, to provide HVAC solutions for the Chennai metro project. ABB drives are used together with electric motors for the control of tunnel ventilation fans. They are a part of the operation of advanced air exchange systems in the stations and tunnels, ensuring passengers’ comfort and saving energy in normal operation as well as contributing in safe evacuation, smoke extract and fire fighting in case of emergency. The dedicated voltage boost feature of ABB’s HVAC drives is intended to address voltage-drop issues caused by long cables in the tunnel network. With this feature, fans are able to provide a nominal air flow without a need for any external equipment to compensate for voltage drop. This is said to bring cost benefits to the project. Almost non-existent harmonics, due to the drives’ active front end design, mitigate the risk of the network overload, ensuring continuous ventilation and power supply. The ‘fireman’s override’ feature supposedly allows VSDs on smoke extraction and pressurisation fans to maintain safe escape routes for the passengers. In the event of a fire, this mode is usually triggered with a special key at the fireman’s control station. ABB is a global technology company that connects software to its electrification, robotics, automation and motion portfolio. Written from company news release.