Self controlling autonomous operating power networks

The paper describes a possible network topology of an autonomous operating network as well as several control activities in normal and disturbance operation, their interaction with network performance and their modelling. The three described control processes are: predefined exchange of power, optimization of voltage profile, and keeping stability during disturbances. The paper focuses on the theoretical aspects of new network design and control. INTRODUCTION OF AUTONOMOUS NETWORKS The expected growth of dispersed generation results in a more complex operation of low and medium voltage grids. Examples of this complexity are: uncertainty of power flows, strong variation of voltage magnitude, possible reversed power flow and variations in short circuit currents and their influence on protection. Furthermore the use of power electronics in the connection of the generation units can result in an increase of harmonic levels and challenges in maintaining stability of the controls. But on the other hand the combination of power electronics and controllable power sources like storage, small gas turbines and fuel cells will help managing these problems in the future. It is even possible that this results in improved performances of the network.