Brazil’s National Electric System Operator (ONS) has published proposed procedures for preparing and validating computational models used in electrical studies of wind farms, solar photovoltaic plants and battery energy storage systems (BESS).
The documents set out technical requirements, procedures and criteria for model validation within Brazil’s National Interconnected System (SIN). The aim is to standardise validation processes, improve transparency and reduce discrepancies during ONS assessments.
The proposals introduce minimum requirements for the preparation, provision and validation of electromagnetic transient (EMT) models for power-electronics-based equipment. They also standardise the Level 1 (N1) and Level 2 (N2) validation processes and consolidate the required tests, test scenarios and documentation.
Another provision allows validation results to be reused for equipment within the same family and model version, reducing the need to repeat work for projects using equipment that has already been validated.
The documents are intended to support future submissions and assessments of power-electronics-based equipment connected to the SIN.
ONS has invited industry participants and manufacturers to submit questions on the proposed procedures by 10 November 2026. Responses will be consolidated in a supporting document scheduled for publication by 30 November 2026.
