An Adaptive and Flexible AGC Scheme for Network Splitting: A Case Study for ENTSO-E Region

This paper presents an adaptive and flexible Automatic Generation Control (AGC) scheme designed for power system splitting and reconnection. The proposed AGC remains fully operational throughout grid splitting, maintaining independent control over each separated area and supporting the transition toward reconnection through improved Area Control Error (ACE) and frequency recovery. It detects splitting by analyzing the frequency coherency of generating units and then autonomously configures the operational mode of each area in accordance with ENTSO-E rules. It applies an adaptive PI controller whose integral gain (IGAIN) is dynamically selected from a lookup table developed through offline tuning and correlation analysis to accommodate various grid configurations. Additionally, during splitting, the AGC performs adaptive reserve activation in each area, rather than relying on predetermined market-based reserve activation. The proposed AGC scheme is validated within a software-in-the-loop (SIL) environment using a representative model of the Turkish Transmission System. The results show that the proposed AGC maintains continuous and adaptive load frequency control (LFC) and improves reserve deployment in both interconnected and isolated operating modes of multi-area power systems. The proposed scheme reduces ACE recovery time by up to 87%, mitigates overshoots, and accelerates frequency recovery. These results demonstrate the scheme’s ability to maintain continuous AGC operation, improve frequency and ACE recovery, and satisfy the adopted ENTSO-E operational performance criteria under splitting conditions.