Investigating impacts of distributed generation on transmission system stability

Driven by the increasing environmental concerns and the increasing amount of new generation technologies, it is expected that many new generation technologies, including renewable generation, will be connected to the electrical power system. A lot of these new technologies will be connected at the distribution level. When the penetration of this distributed/dispersed generation (DG) is low, the impacts of the DC on the transmission system transient stability may be neglected. However, when the penetration of DG strongly increases, its impact is no longer restricted to the distribution network but begins to influence the whole system. In this paper the impact of DG on the transmission system transient stability is investigated by considering different types of DG technologies and various penetration levels. It is observed that both the types of DG technologies and the penetration levels of DG in the power system have a strong influence on the transmission system transient stability.