Hardware-In-the-Loop Design and Optimal Setting of Adaptive Protection Schemes for Distribution Systems With Distributed Generation

The constantly increasing presence of distributed generation (DG) in modern distribution systems induces grid configuration alterations, affecting thus the short-circuit levels and fault current paths. To address all arising protection challenges, adaptive protection is being implemented. This paper presents an innovative hardware-in-the-loop adaptive protection scheme, which incorporates real-time simulation, multifunction protection, centralized control, and optimal calculation of protection settings. The proposed adaptive scheme is based, first, on the determination of optimal relay setting groups, and then on their online self-adjustment, providing a continuously tuned protection scheme to the variable system operating modes. The efficacy of the proposed solution is demonstrated through two distribution test networks with embedded DG.