Establishment of a Micro-Grid System and Supply-Demand Control in Grid-Connected Operation

摘要

Shimizu Corporation, The Chugoku Electric Power Co., Inc., and Meidensha Corporation established a micro-grid system of which 50% of the entire power capacity was provided by a photovoltaic power generation (PV) system, in Zhejiang Province of the People's Republic of China. The micro-grid system controls the supply- and demand by combining a supply-demand control system (using control based on operation plan patterns and load following control) with local following control by a power system stabilizer. This system has been in operation since November 2008. For grid-connected operation, we conducted a performance test of supply-demand control, by combining a diesel engine generator, an Electric Double Layer Capacitor (EDLC) type power system stabilizer, and a secondary battery type power system stabilizer, and also tested the performance of automatic operation mode with actual loads in the demonstration project. A favorable supply-demand control result was obtained as we could maintain the power flow at the point of interconnection.