Abstract

In recent years, using of small generators connected to distribution networks has been increasingly preferred to supply local loads. They are called embedded or distributed generators because of they are connected to distribution networks. Both of them are generally used synonymously and interchangeable. In this study, dynamic performances of embedded genera-tors are observed during and after the faults. The effects of symmetrical and unsymmetrical faults on the operation of the industrial plant included embedded generation units and also the stability of embedded generators is investigated for a medium voltage radial distribution network. Small-embedded generators are subjected to low frequency electro-mechanical oscillations that cause dynamic instability problems due to faults in utility side or inside. In this paper, these oscillations caused by balanced and unbalanced faults are simulated by using SIMPOW simulation software tool.

Key words: Voltage sags, embedded generators, distribution networks, power system stability.