| Abstract |
The installation of distributed generations (DGs) at demand end is much interested by customers along with the liberalization of electric power market and worldwide interest on utilization of renewable energy source (RES) etc. However, it is apprehensive that installation of a number of small-scale DGs (less than several tenth of kW) to the existing distribution network of power grid may cause voltage instability and deterioration of supply power quality to customers. To cope with these problems, a concept of Micro Grid, which integrates DGs and customers as an unit of network, and is operated independently from the power grid, is proposed and being verified with model systems.Most of DGs, such as micro gas turbines, gas engines and fuel cells, are interconnected to the ac power supply network for customers through power conversion systems (PCS). In such cases, their basic performances are different from the conventional rotating machine, and the interaction among them should not be neglected. The focus of this paper is to propose novel control schemes for PCS based DGs and rotating machines respectively to secure both of operational stability and supply power quality of a micro grid. The performances of the micro grid are verified by simulation studies. |
