System operation emphasizing DSO/TSO interaction and coordination

Power systems with a high penetration of distributed energy resources (DER) at the distribution voltage levels, create a need for a new level of interaction between transmission system operators (TSOs) and distribution system operators (DSOs). This Technical Brochure focuses on two main aspects of the TSO-DSO relationship: operational changes resulting from the presence of DER and the impact of DER on frequency management, voltage control and system restoration.