Reliability assessment of small power system with dispersed generators in isolated island

Recently, as it is important to reduce CO2 emission, dispersed generators such as photovoltaic system (PV) and wind turbine generator (WTG) are introduced aggressively. A small power system in such an isolated island is sensitive to output fluctuation of dispersed generators because total generator capacity of the system is small. To reduce the fluctuation, many researches have been studying how to control the fluctuation. Though it is important to smooth the output of the generator, we think the reliability is a more important issue when the dispersed generators are introduced in small systems. In this paper, we discuss on the reliability of a small isolated power system with dispersed generators. We investigate how much capacity of PV or WTG is equivalent to a diesel generator from the viewpoint of supply reliability. Thus, we will make clear the required capacity of dispersed generator to secure the reliability of a power system. The method and results of this analysis for a small island system can be applied to a smart grid.