抄録
The “New Energy Plant” had been built at the Aichi EXPO. 2005 site as part of the “Demonstrative Project of Regional Power Grid with Various New Energies”. The plant includes three types of fuel cells, photovoltaic power generation system and Sodium Sulfur (NaS) battery. One of the purposes of the demonstrative project is to verify supply/demand control to minimize the effect on the utility grid. Isolated operation of a microgrid is an ultimate state to be no interaction between utility grid and the microgrid. It also increases value of the microgrid. These new energy generators and battery are connected to the microgrid via inverter and there are no rotating generators. There are no established techniques to startup and control voltage and frequency of such system. The authors carried out a verification test of isolated operation of the microgrid.
This paper presents the control strategies for isolated operation of a microgrid configured with some new energy generators. Simulation results of system excitation, load share operation, and response for load change such as an induction motor is connected are shown. This paper also presents the test result of isolated operation of a microgird on Aichi EXPO. 2005. The system had separated from utility grid, and performed stable controllability for load change for around three weeks.
