Distribution network interconnection for facilitating the diffusion of Distributed Generation

The foreseen increasing diffusion of Distributed Generation (DG) in the distribution networks is giving the impetus to the study of active distribution networks. The recent EU directive 54/2003 may help to accomplish these objectives by defining DG as a planning alternative for distribution expansion problems. In the paper, considering the importance of interconnection in active networks, meshed schemes have been deeply studied both in steady state and transient condition in order to point out the effect on the integration of DG. In particular, different types of meshed distribution networks have been examined and compared to the radial scheme. Steady state simulations have been performed in order to assess the impact on the voltage profile, on the short circuit level, on the power losses, on the continuity of service, and on the exploitation of lines and transformers. Finally, the greater attention has been paid to analyse the dynamic behaviour of meshed distribution networks. In order to complete the study a mix of different DG sources — directly connected generators or with static converters — have been considered.