Output leveling of wind power generation system by EDLC energy storage system

Utilization of renewable energy is becoming increasingly important from the viewpoints of environmental protection and conservation of fossil fuel. However, the generating power of renewable energy is always fluctuating due to the environmental status. Energy storage systems are indispensable in compensating these fluctuating components. An energy capacitor system (ECS) composed of an electric double-layer capacitor (EDLC) with power-electronics devices is useful for compensation of fluctuating power, since it is capable of controlling both active and reactive power simultaneously. This paper proposes a current-source ECS (CS-ECS), which consists of an EDLC, a bidirectional buck-boost DC-DC converter, and a bidirectional inverter. We present the control systems for active/reactive power control of CS-ECS, and show the effectiveness of CS-ECS through computer simulations for the case of a wind power generation system. (c) 2006 Wiley Periodicals, Inc.