The National Electricity Coordinator submits a report to the SEC on the February 25 blackout.

By CEN
March 19, 2025

This press release was published in English using an automatic translation system.

Santiago, March 19, 2025. The National Electric Coordinator sent to the Superintendency of Electricity and Fuel (SEC) the Failure Analysis Study (EAF) of the power outage that affected a large part of the country on Tuesday, February 25.

"The delivery of this report demonstrates our commitment to transparency and technical excellence, and is the result of arduous work, which required analyzing and processing more than a thousand reports received from companies in just 20 days," emphasized the Board of Directors of the National Electricity Coordinator. The report is a milestone that will be complemented by additional studies on specific topics related to the operation of the National Electricity System, as well as the input of independent experts, such as the Electric Power Research Institute (EPRI) of the United States, which will review the document and develop proposals for improvements, and a group of distinguished academics from Chilean universities who will verify the causes of the fault's propagation.

In addition, this will be complemented by audits already commissioned by the National Electricity Coordinator. One will be conducted by Interchile to thoroughly review the control and protection systems of its 500 kV transmission lines, and another will be conducted by Transelec due to failures recorded in its SCADA system and internal and external voice and data telecommunications systems.

Key aspects of the report The document contains nearly 400 pages with detailed information on the causes of the failure and the behavior of the various facilities that are part of the National Electric System during the same.

Regarding the source of the failure, at approximately 1:35 p.m. on February 25, Interchile reported a problem with the communications module of one of the protection functions of the Nueva Maitencillo-Nueva Pan de Azúcar Line, which had been deactivated.

This posed no risk to the line's operation, given that the backup system was operating normally. However, at 3:13 p.m., Interchile personnel rebooted the problematic communications module and then attempted to resynchronize the disabled function without notifying the Coordinator and, according to available information, without taking the precautions established in the manufacturer's manuals for the equipment involved. This resulted in the line being completely disconnected.

The failure to report or request authorization for the intervention prevented the Electricity Coordinator from taking operational measures, as is customary in these cases, aimed at minimizing risks to the system. Furthermore, the study provides background on why the fault spread until it caused a total blackout in the National Electric System, despite the mitigation resources available in the grid. Immediately after the fault occurred, the system formed two electrical islands: one in the north and another in the center-south. These islands were unable to maintain stability and resulted in a total blackout of the National Electric System.

The report identifies deficiencies in the response of mitigation resources, including automatic consumption and generation disconnection schemes, as well as the performance of some generating plants during the event. Finally, it provides details on how the Service Recovery Plan was applied and the difficulties encountered during its implementation due to failures in the SCADA and communications systems of Transelec and other companies.

The document submitted to the SEC is available for review on the National Electric Coordinator's website.