Abstract: With the connection of main network and distribution network through regression analysis, an analytic model on economic benefits and voltage stablity of DG integrated into distribution network is established based on spot price theory. A testing system is established by intergrating 4 DGs into the distribution network connceted to Bus 8 in IEEE 30-bus system.A quantitive analysis of economic benefits and voltage stablity before and after DG's integration is performed for 6 typical days. Results demonstrate that after reasonable integration of DG, several different goals can be achieved. Payment prices of end-users are reduced and possible transmission congestion is eliminated effectively. Loss rates of distribution network and main network are decreased significantly, thus improving power transmission efficiency. Total power purchase costs of distribution network and main network are also reduced, thus elevating market operation efficiency. DG owners can obtain relatively high profits by full power generation due to comparatively lower costs during load peak. Distribution network voltage stability is also enhanced. With the development of DG technique, DG will become an effecitve supplement to traditional grid with its possessing cost and location advantages.

Key words: distributed generation, virtual generator, locational marginal price, economic benefits, voltage stability