Axia Substation Failure Triggers Outages in Brazil

Axia Energia suffered a transmission system failure on 7 September that triggered blackouts across dozens of municipalities in the Brazilian states of Ceará and Paraíba. According to national grid operator ONS, the incident began at 18:54 with the shutdown of the 230 kV busbar at the Milagres substation in Ceará, cutting 365 MW of power load.

The interruption cut 173 MW in the concession area of Enel Ceará and 192 MW in that of Energisa Paraíba. Grid operator ONS noted that the shutdown at Milagres also led to the disconnection of the Coremas substation in Paraíba and the Rio Alto Photovoltaic Complex because of the radial network configuration. Remote terminals of transmission lines linked to Milagres opened, coinciding with the de-energisation of the 230 kV E4 reactor.

Grid restoration started at 19:17. Normalisation was completed at Milagres by 19:45, while Coremas completed restoration between 19:28 and 19:57. Enel Ceará reported full restoration for its customers in the Cariri and Centro-Sul regions by 19:47. Energisa Paraíba stated that 77 municipalities in the Paraíba backcountry lost power entirely due to the transmission event.

Axia stated that it began restoring loads immediately following the incident and started normalising the substation configuration at 19:17. The company noted that the causes of the disconnection remain under investigation.