Life-Cycle Asset Management of Non-Switchable Line Reactors: Rapid Reserve Switching in Brazil’s Interconnected Power System

In Brazil’s Interconnected Power System, reactive-power compensation on the most heavily loaded 500 kV corridors relies on non-switchable line shunt reactors designed for continuous service. Since it cannot be remotely switched, any maintenance, failure, or unplanned shutdown forces operators to de-energize the circuit and dispatch crews to reconfigure hard-wired connections. This lengthy procedure can leave system-critical lines out of service for hours, eroding the grid’s security margin. This paper proposes automating spare-reactor transfer switching in the substations of Brazil’s largest transmission company to enhance operational flexibility and the safety of the system and personnel, while also safeguarding power-transfer capability. It is the result of a project to modernize its assets and improve the operational resilience of the Interconnected Power System. An initial reliability evaluation used operational disturbance reports and availability indices to quantify the impact of each unavailability event.