IIT Kanpur professor builds smart fault limiter prototype that can save power grids from short circuits

Satyajit Banerjee, a professor of physics at the Indian Institute of Technology, Kanpur (IIT-K) along with his team, has built a prototype of a smart current limiter, which can potentially help save power grids from massive power surges and short circuits. 

The prototype uses a range of hall sensors around a standard superconducting fault current limiter (SFCL), which combines leads to better handling of power surges and monitoring of any faults in circuits, the Ministry of Science and Technology said in a statement. 

Simply called Smart Superconducting Fault Current Limiter (SCFLs), the prototype is based on the core working principle of a superconductor in a power circuit. In a standard SFCL, the superconducting material offers zero resistance to passing electric current up to a specific threshold value — typically known as the critical current of an electrical circuit.

In case of a power surge, when the electric current in a circuit exceeds the critical value, the superconductor offers high resistance to the passing current. This breaks the surge, in an effort to protect the circuit. Applications of such SFCLs have been increasing across power grids — where short circuits and power surges can produce significant losses and damages.

With the SCFLs in question developed by Banerjee and his team, the advantages lie in that the sensors monitor circuit current, and employs a switch that can shunt (or switch) excess current in a circuit to a low resistance parallel circuit. This can make sure that not only are the original properties of an SFCL retained but power surges of current values much lower than the critical threshold of the superconductor can be controlled.

The smart fault limiter conceptualised by Banerjee’s team can also constantly monitor power distribution in a circuit and potentially detect any signs of instability in the superconductor.

Going forward, Banerjee and his team said that they also plan to build large current automatic switches of higher efficiency, which can enable the shunting of large power surges to the additional circuit alongside the SCFLs device. They also eventually plan to build system intelligence to predictively understand any upcoming faults in the superconductor material — which can help prevent unexpected damages even further.

The Ministry of Science and Technology stated that a national patent for the smart fault limiter device has been filed already and that the prototype is ready for deployment in large power grids across the country. The Advanced Manufacturing Technologies Program of the Department of Science & Technology (DST) lent assistance to help build it.