The ONS (National Electric System Operator) increased the energy export limits from the Northeast to the Southeast/Mid-West and the North from the current 8 GW to 10.8 GW. The new parameters came into effect last Wednesday night (27).
According to the Operator, after the occurrence of August 15th, the export limits of this subsystem were reduced, within a conservative operational policy that aimed to ensure the balance of the SIN (National Interconnected System) until the causes for the disturbance were identified. The adoption of these more restricted parameters was an ONS prerogative, provided for in Network Procedures.
“At first, the Northeast-Southeast/Central-West (FNESE) energy flow was restricted to amounts equal to or less than 5 GW and now it can be equal to or less than 6 GW. In the Northeast-North Flow (FNEN), the maximum level was 3 GW and is now at 4.8 GW”, informed the ONS.
According to the Operator, the new limits are still lower than those applied in periods prior to August 15th. The total recomposition of these limits is linked to the completion of the recommendations highlighted by the ONS to improve the performance of the plants, as described in the draft of the RAPv(Disturbance Analysis Report).
The review of exchange limits was possible after new studies using a new provisional database for stability studies.
The ONS pointed out that the objective was to establish a reference aligned with the observed performance of the plants during the disturbance, since the root cause of the incident was the inconsistency in the data provided by the agents and those measured at the time of the interruption.