Stability Analysis for the Distribution Networks with Distributed Generation

A high penetration of distributed generation (DG) may influence the operation and control of the distribution system and the transmission system, leading to technical issues that must be identified and analyzed. The distributed generators are small or medium scale units connected to the low or medium voltage networks (LV or MV). Due to their low inertia for small rotating machines, these distributed generators are very sensitive to network disturbances and can cause many technical and operating issues regarding the DG stability. This paper focuses on these stability aspects taking into account the location and the clearing time of the short circuits. Various assumptions about DG coupling mode on LV and MV networks, DG regulation systems, DG rated power and interaction between DG are investigated. Influences of DG with power electronic interface on the stability are discussed. For a large distribution network with a high penetration of DG, a dynamic equivalent reduction technique is used for the study