AGC Adaptation to the European aFRR Framework: Modeling and Validation of the Spanish Master Regulator

Abstract

Load–frequency control is a fundamental function in the operation of power systems, responsible for maintaining within acceptable values the frequency of the system and the scheduled power exchange. In 2024, the Spanish Transmission System Operator, Red El´ectrica, implemented a new Secondary Regulation Service (SRS) as part of the European PICASSO initiative for the coordination of automatic Frequency Restoration Reserves. This transition represents a fundamental change with respect to the former shared peninsular regulation scheme and requires a profound adaptation of the national Automatic Generation Control system, particularly of the master regulator.This paper presents a comprehensive framework for the modeling, tuning, and validation of the Spanish master regulator under the new SRS. The proposed approach integrates a detailed simulation of the new SRS. The methodology is validated through a realistic case study that reproduces actual SRS operating conditions and evaluates both master regulator performance and BSP dynamic response. The results demonstrate the effectiveness of the proposed modeling approach and its applicability to other European aFRR implementations.