BRAZIL BLACKOUT; 15th AUGUST 2023

BRAZIL BLACKOUT started at 8:30 am on August 15, 2023, with an interruption of around 19,000 MW, out of a total of 73,000 MW that were being serviced at the time, representing approximately 27% of the total load at that hour. The event caused the electrical separation of the North and Northeast regions from the South, Southeast/Center-West regions, with the opening of interconnections between these regions, affecting 25 states and the Federal District.

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Considering the country's geographic regions, loads were suspended in the North region (5.4 thousand MW), part of the Northeast region (7 thousand MW - 56%) and there were controlled load cuts (Regional Load Relief Scheme - ERAC) in part of the Southeast/Center-West and South subsystems (6.4 thousand MW). In the initial analysis, the ONS indicated that the system acted as expected, avoiding a larger cut in these regions.

CAUSE: According to the National Electric System Operator Brazilian Portuguese: Operador Nacional do Sistema Elétrico, ONS), the blackout occurred due to the opening of the wide area synchronous grid between the North and Southeast regions of Brazil, in a 500 kilovolt circuit near Imperatriz, Maranhão. The exact cause of the blackout is currently unknown and under investigation.

AFFECTED AREAS: The blackout affected the Federal District and all states of Brazil, except Roraima. The North region was most affected by the blackout, with a 83.8% drop in power supply, followed by the Northeast region, with a 44.4% drop.

RECOVERY: Shortly after the blackout, the process of restoring electricity began. By 9:16, 6 gigawatts of energy was restored.

1. Electricity in the South and Central-West regions was fully restored by 9:05 and 9:33, respectively.

2. By 10:22, 27% of the electrical charge in the North region and 68% in the Northeast region was restored, and by 11:00, electricity was fully restored in the Southeast region.

3. By 12:30, 41% of the electrical charge in the North region and 85% in the Northeast region was restored.

4. By 14:49, electricity was restored in all regions of Brazil.

INITIAL ASSESMENT: In the initial assessment, demonstrated that an event of this nature, in isolation, would not be sufficient to cause the interruption of electricity observed in the occurrence in question. The disconnection disproportionately reflected on adjacent equipment and caused electrical oscillations (voltage and frequency) in the system in the North and Northeast regions, and that after 600 milliseconds, the Synchronism Loss Protection (PPS) was activated, responsible for the controlled opening of lines that make up the North - Northeast, Northeast - Southeast and North - South interconnections, separating the SIN into three electrical areas. Therefore, at this time, more documents are being received and evaluated so that a more in-depth and detailed diagnosis of the situation can be made.

LAST FIVE BLACKOUTS OF BRAZIL

Brazil  has already had some of the biggest blackouts in the world , such as the interruption in supply to 90 million people in 2009, and traumatic episodes, such as the blackout that left almost all of Amapá for ten days without electricity.

• Amapá (2020)

On November 3, 2020, Amapá's main substation caught fire, affecting power supplies in 13 of the state's 16 municipalities. There was delay in the restoration and chaos in public services. Almost 800,000 were without electricity for ten days.

• Brazil (2018)

On March 21, 2018, all regions of the country were affected by a blackout, which was more intense and longer in the North and Northeast. The states of Alagoas, Amapá, Amazonas, Bahia, Ceará, Maranhão, Pará, Paraíba, Piauí, Pernambuco, Rio Grande do Norte, Rondônia, Sergipe and Tocantins were the most affected.

The blackout occurred because of a failure in the transmission line connected to the Belo Monte hydroelectric plant, in Pará, which could not withstand an increase in load. In total, 70 million people were affected.

• Northeast (2011)

A failure in a substation located on the border of Pernambuco and Bahia left 47 million people without electricity throughout the Northeast, with the exception of Maranhão, on the night of February 3, 2011. There were several hours of interruption in supply.

• Brazil and Paraguay (2009)

On the night of November 10, 2009, three transmission lines from the Itaipu binational power plant failed. The sharp drop in energy demand caused the automatic shutdown of 20 hydroelectric turbines, leaving nearly 90 million people without power in Brazil and Paraguay. Four Brazilian states were fully affected. About 90% of the neighboring country also lost power.

• Brazil (1999)

One of the biggest blackouts in history was recorded on March 11, 1999. Ten states and the Federal District were left without supply overnight. In all, 76 million people were affected.

At the time, the government blamed lightning that would have hit a distribution tower in Bauru (SP). Later, it was proved that this was not the cause. System overload was later pointed out as the reason. Two years later, there was energy rationing throughout the country, except in the southern region.