Future distribution systems with dispersed generation will require network security measures as transmission systems of today

The paper describes typical developments of blackouts from simple cause to cascading outages. Possible measures to increase the system observability, combined with power electronic equipments as controlling elements, can lead to a future closed loop control of the power supply. The possible increase of the overall network security by protection security assessment (PSA) and dynamic network security assessment (DSA) will be shown. The described network and protection simulations, which are available today for the transmission sector, have to be adopted to future distribution systems with dispersed generation.