Electrical & Computer Engineering, Department of


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J. Cheng, "Configuration and optimization of a novel compressed-air-assisted wind energy conversion system," Ph.D. dissertation, University of Nebraska-Lincoln, Lincoln, USA, 2016.


A DISSERTATION Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Doctor of Philosophy, Major: Electrical Engineering, Under the Supervision of Professor Fred Choobineh. Lincoln, Nebraska: July, 2016

Copyright (c) 2016 Jie Cheng


The increasing concerns over the environmental impact of carbon emissions and the unsustainability of conventional fossil fuel power plants are stimulating interest in the implementation of renewable energy in current power systems. Among all of the renewable energies, wind energy holds a prominent place because of its high output and the maturity of the technology. However, like all of the other renewable energies, integration of wind energy into the power grid causes some quality and control issues, such as overvoltage or undervoltage and frequency excursion.

To mitigate these issues and build a robust wind power system, a novel structure referred to as a compressed-air-assisted wind energy conversion system (CA-WECS) is proposed in this dissertation. The CA-WECS converts the wind-generated mechanical spillage to compressed air when the wind is a surplus and regenerates power from the compressed air storage when the wind is a deficit. The key component of the new system is a variable displacement machine (VDM), which can work as a compressor or air motor/expander depending on the power gap between wind power and load/command.

This work addresses the configuration of the CA-WECS in detail. The functions of the system components are explained and the fundamentals of the proposed VDM are explicitly described. A regulation policy for dispatchable generation is simulated and studied. The results show that renewable generation is increased by 15-20% under various wind conditions, accounting for a 20-30% revenue increment in a dynamic market environment.

Advisor: Fred Choobineh