Switchgear is, perhaps, as old as the usage of electricity itself. High voltage switchgear, in particular, has shown a clear-cut technology progression along with interrupting medium used. As of now, for voltages 145 kV and above, sulphur hexafluoride (SF6) circuit-breakers are exclusively used. Design of both, air-insulated switchgear (AIS) and gas-insulated switchgear (GIS) require addressing contradictory requirements in electromagnetic, thermal, structural and mechanism design. Despite being ideal in all the technical requirements as an interrupting medium, SF6 is one of the most potent greenhouse gases, with the highest global warming potential. This has necessitated the development of alternative media for switching as well as insulation. Therefore, there has been development of vacuum circuit breakers as well, in the erstwhile solely SF6 domain and many companies have already introduced products up to 72.5 kV. Their use in the higher voltage range is being investigate d as series interrupters, as well as development of single interrupters. Frequent switching of breakers has further stressed the interrupters and the associated mechanism. Thus, monitoring of switchgear has evolved as an industry of its own. On the whole, design of switchgear is a challenging task and requires inter-disciplinary research to address all its problems.
Avinash S. Bhangaonkar completed his undergraduate studies in electrical engineering from VJTI Mumbai, India, in 1999. He obtained his masters? degree in electronic materials and devices from the University of Cincinnati, Ohio, USA in 2002. He got his Ph.D. in the area of high-voltage engineering and high-frequency electromagnetics from IIT Bombay, Mumbai, India in 2011. For the past three years, he has been working with Crompton Greaves Ltd., Global R&D centre, Mumbai, on high-voltage switchgear. His interests include high-voltage switchgear design, partial discharge analysis and condition monitoring of high-voltage electrical equipment.