Feasibility study of a hybrid wind turbine system - integration with compressed air energy storage

The paper presents a new hybrid wind turbine system that is formed by a direct mechanical shaft connection of the wind turbine with an air expander, which converts stored compressed air energy to mechanical energy. A power split device is designed to synthesize the power delivered by the wind turbine and the air expander. The study is conducted to understand the relationship between the power delivered wind and compressed air energy. A small scale hybrid wind turbine system is mathematically modelled, analyzed and verified using a laboratory experimental test rig. By utilizing the compressed air energy storage, it is shown that the hybrid wind turbine system can provide smooth power output under wind speed variations. Such a direct connection structure reduces the overall system costs by using one generator instead of two. The study demonstrates the benefit of improved efficiency brought to the turbine operation by the hybridization of wind energy and the stored energy