Development of Economic and Stable Power-Sharing Scheme in an Autonomous Microgrid with Volatile Wind Power Generation

Abstract

Abstract—This article investigates the problem of economic and stable power sharing in an autonomous microgrid including a variety of dispatchable distributed energy resources and wind turbine generator. To minimize the operational cost of the microgrid considering the nature volatile of wind power generation, the frequency-droop coefficient of each dispatchable distributed energy resource dispatchable distributed energy resource should be properly scheduled to yield the desired power sharing among multiple dispatchable distributed energy resource dispatchable distributed energy resources. Also, it has previously been shown that the selection of frequency-droop coefficients has a significant effect on the small signal stability of the system. Consequently, a microgrid may suffer economic or stability degradation as variations in wind power generation and load demand if inappropriate frequency-droop coefficients are employed. This article therefore presents a detailed procedure of obtaining optimal frequency-droop coefficients of dispatchable distributed energy resources. The optimal droop coefficients of dispatchable distributed energy resources are obtained according to an optimization problem. The eigenvalue-based stability constraints are imposed on the objective function, in particular, to ensure that the microgrid system has a sufficient stability margin at all possible operation conditions. Particle swarm optimization is used to solve this problem. The simulation results show that the economy and stability of the microgrid can be improved significantly using the proposed method.

Keywords:

• droop control
• economic dispatch
• power sharing scheme
• microgrid
• small signal stability
• volatility
• wind power generation

Additional information

Notes on contributors

Bingke Yan

Bingke Yan was born in Hubei Province, China. He received the B.S.E.E degrees from Wuhan University, Wuhan in 2011. He is currently pursuing the Ph.D. degree at the Wuhan University. His research is focused on power system control and stability analysis.

Bo Wang

Bo Wang received Ph.D. degree in 2006 from Computer School, Wuhan University, Wuhan, China. He is currently an associate professor of School of Electrical Engineering in Wuhan University. His research is focused on dispatching, operation and optimization of large scale power systems.

Fei Tang

Fei Tang received the Ph.D. degree in 2013 from the School of Electrical Engineering, Wuhan University, Wuhan, China, where he is currently working as a post-doctoral. His main research interest is the application of artificial intelligence in power system.

Dichen Liu

Dichen Liu is currently a professor of School of Electrical Engineering in Wuhan University, Wuhan, China. He is an IEEE Member. His current research includes power system operation and control such as low frequency oscillation, nuclear power and system stability assessment.

Zhihao Ma

Zhihao Ma received the B.E. degree in 2012 from the School of Electrical Engineering, Wuhan University, Wuhan, China, where he is currently working toward the M.E. degrees. His main research interest is power system feature extraction in fault condition.

Yaning Shao

Yaning Shao received the B.E. degree in 2012 from the School of Electrical Engineering, Wuhan University, Wuhan, China, where she is currently working toward the M.E. degrees. Her main research interest is partitioning method for reactive power and voltage.