Abstract
This paper describes a newly developed demand and supply control system for micro grid. Renewable energy is expected to reduce green house gases and becomes widely used in the world. By contrast, fluctuated power output from renewable energy may affect the power systems, especially frequency. The demand and supply control system for micro grid is expected to reduce it. The developed system consists of 4 control layers. The first layer is a planning of demand and supply every 30 minutes until next day. The second layer is an economic dispatch control (EDC) every 1 minute. The third layer is a load frequency control (LFC) every 1 second. The last layer is battery local control every 0.1 second. The developed system can control frequency stably against fast change of renewable energy output, and can operate generators economically by cooperating EDC and LFC, and using battery local control. Moreover, the battery can be operated systematically by managing battery states of charge (SOC). The developed system is verified using a real time digital simulator with promising results.
