Busbars, the materialization of nodes in power grids

Today we celebrate the 199th anniversary of the German physicist Gustav Kirchhoff, who was born on March 12, 1824, famous for his corollaries known as Kirchhoff’s Laws:

• Law of tensions: The algebraic sum of the potential differences (voltages, tensions) in a mesh is equal to zero.
• Law of currents: The algebraic sum of all currents in an electrical node is equal to zero.

In electrical substations, the electrical nodes (convergence of three or more circuits) materialize as conductors stressed gantries frames that we call busbars (barra in Spanish, barramento in Portuguese), to which the different circuits are connected.

The busbars are critical elements due to the high short-circuit current that is generated during the occurrence of a fault and the need to trip all the circuit breakers that converge on it in order to isolate it from the system.

The fault in a busbar can be produced by different causes, the main ones being: the detachment of a conductor, the appearance of electric arcs in HV equipment, and wrong grounding manoeuvre of energized busbars.