ABB is well advanced in plans to develop, design and manufacture a 1200 kV circuit breaker. This will make it the highest voltage AC unit available. It is to be deployed at a national test station being constructed by Power Grid Corporation of India (PGCIL), India’s central transmission utility, at the 1200 kV Bina substation in the central Indian state of Madhya Pradesh.

The CB will being jointly developed by ABB engineers in Switzerland and India, with the support of PGCIL, and will be manufactured at the company’s production facility in Vadodara, India. It will contribute to a much larger project, the construction of India’s 1200 kV transmission system, which will be operating at the highest AC voltage level in the world and prompted by the country’s need to develop an efficient, low-loss and high capacity T&D infrastructure to deliver the electricity being created by India’s fast expanding power sector.

Th e unique feature of the new design, said to result in a space saving of up to 60 percent compared with conventional designs, is a housing filled with insulant gas which will also contain the disconnector. This configuration also protects critical components from environmental exposure and brings down the centre of gravity of the tank, thereby increasing its ability to withstand seismic shocks. Other design features include modular ring type current transformers, partial discharge sensors and composite bushings.