Impact of distributed generation grid connection strength on power system transient stability

Concern on implementing distributed generation (DG), including DG based on technologies using renewable energy sources, is increasing worldwide. Due to the considerably smaller dimension compared to the conventionally large-scale synchronous generators, DG is connected to the distribution networks. Distribution networks vary in topology; the way of connecting DG to distribution networks may vary as well. Both variations will affect the impedance in between the DG and the transmission network and thus the connection strength. With a high DG penetration level, the DG connection strength may influence the transmission system transient stability in case of a fault. This paper investigates the impact of DG implementation on transmission system transient stability by focusing particularly on the DG grid connection strength.