A new approach to retrofit plans for distributed energy resources to mitigate adverse impacts on bulk power systems stability

This work presents a new methodology to assess the need of a retrofit plan to readjust anti-islanding protection of distributed energy resources (DERs) with focus on bulk power systems stability. The proposed approach aims to reduce DERs cascade disconnection during major disturbances in transmission networks, a phenomenon that can amplify or result in major blackouts in power systems with high or moderate DERs penetration. The proposed methodology is based on the assessment of Dynamic Security Regions with the incorporation of a simplified modeling to represent DERs cascade disconnection. As a result, recommendations for executing a retrofit plan with a low cost, preserving an adequate level of security, are provided. Initially, the impact of DERs disconnection on the Brazilian Interconnected Power Systems (BIPS) is demonstrated, highlighting the importance of modeling such effect in stability studies. Then, the proposed methodology is applied to the BIPS, evidencing its benefits by specifying the minimum amount of DERs that needs to be submitted to a retrofit plan to guarantee an adequate level of security.