Load Frequency Control of Power Systems with Governor Deadband (GDB) Non-linearity

Abstract

Load frequency control of power systems with a governor deadband (GDB) is studied in the paper. The effects of GDB on the linear active disturbance rejection controller (LADRC) are analyzed first. It is shown that the limit cycle can be avoided by reducing the controller and/or observer bandwidth. However, the disturbance rejection performance will be degraded. To maintain the performance of the original LADRC controller, two anti-GDB schemes are proposed. One is based on the observer structure of active disturbance rejection control, which utilizes the output of the governor to reconstruct the input to the system in order to correctly estimate the controller states. Another is based on the error between the realistic output of the governor and its ideal value which is fed back and added to the output of the original LADRC. Simulation results on a single-area and a two-area power system with the GDB show that the two schemes are effective in reducing the limit cycle caused by the GDB. The observer-based anti-GDB has some limitations in practical implementation and performance, while the error-compensation-based scheme is simple to implement and can approximate the disturbance rejection performance of the original LADRC.

Keywords::

• load frequency control
• electric power system
• governor deadband (GDB)
• active disturbance rejection control
• anti-GDB scheme

Additional information

Notes on contributors

Wen Tan

Wen Tan received the B.Sc. degree in applied mathematics and the M.Sc. degree in systems science from the Xiamen University, Xiamen, China, and the Ph.D. degree in automation from the South China University of Technology, China, in 1990, 1993, and 1996, respectively. He joined the faculty of the Power Engineering Department, North China Electric Power University, Beijing, China, in 1996. He was a Postdoctoral Fellow in the Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Canada, from 2000 to 2001. He is currently a Professor with the School of Control and Computer Engineering, North China Electric Power University. His research interests include modeling, analysis, and control of complex industrial processes.

Shuaibing Chang

Shuaibing Chang received the B.E. and M.E. degrees from the Hebei University of Science and Technology, China, in 2009 and 2012, respectively. He is currently working toward the Ph.D. degree at the School of Control and Computer Engineering, North China Electric Power University. His research interest includes load frequency control of power systems.

Rong Zhou

Rong Zhou received the B.E. and M.E. degrees from the North China Electric Power University, China, and the Ph.D. degree from the Chinese Academy of Science, China, in 1999, 2003, and 2015, respectively. She is currently a Lecturer with the School of Control and Computer Engineering, North China Electric Power University. Her research interests include computer applications in power systems.