Influence of Different Practical Models on the First Swing Stability of Turbine Generators

Abstract

There are two popular practical models of synchronous generators used in power system simulation, both based on Park equations, defined as assumed A and assumed B respectively, according to the different assumptions. To study the influence of the different models on the first swing stability calculation precision, the physical essence of the two assumptions are revealed in theory, and it is obtained that assumed A takes account of the mutual leakage flux linkage between field and damping windings and neglects the self-leakage flux linkage of damping winding, the opposite of assumed B. Taking a 300-MW turbine generator as an example, first swing stability limits calculated by two practical models are compared; simulation results are verified by the time-step finite-element model. The influence of line reactance and excitation system on first swing stability limits is studied. Results show that the first swing stability limit calculated by the practical model with assumed A is closer to the result of the time-step finite-element model, since assumed A takes account of the larger mutual leakage flux linkage. Therefore, the practical model with assumed A is more accurate. The result provides reasonable reference to select synchronous generator models in power system simulation.

Keywords:

• first swing stability
• turbine generator
• practical model
• time-step finite-element model
• Park equations
• assumed A
• assumed B
• mutual leakage flux linkage
• self-leakage flux linkage
• damping winding

Additional information

Notes on contributors

Xu Guorui

Xu Guorui received his B.S.E.E. from Taiyuan University of Technology, Taiyuan, China, in 2007 and his M.S.E.E. and Ph.D. from North China Electric Power University, Beijing, China, in 2010 and 2014, respectively, majoring in electric machines and apparatus. Presently, he is a lecturer at North China Electric Power University, Beijing, China. His research interests include models and parameters of synchronous machines and the coordinated operation between the generator unit and power grid.

Liu Xiaofang

Liu Xiaofang received her B.S.E.E. from Chong Qing University, Chongqing, China, in 1982. She is currently a professor at the School of Electrical and Electronic Engineering, North China Electric Power University, Beijing, China. Her research interests include the analysis of AC electrical machine and system and energy savings of motor systems.

Luo Yingli

Luo Yingli received his B.S.E.E. from Tsinghua University in 1968. From 1968 to 1980, he worked in an electric machine plant in Hei Longjiang Province, China. After he graduated with his M.S. in electrical engineering from Harbin Institute of Electrical Technology in 1983, he worked at Moscow Power Engineering Institute as a visiting scholar for two years. He is currently a professor and doctoral supervisor at North China Electric Power University, China. He is a member of the Large Machines Subcommittee of the Chinese Society of Electrical Engineering (CSEE) and a member of the Electrical Technology Committee of National Petroleum & Chemical Industry. His research mainly focuses on the electric machine theory, abnormal operation and non-linear models of large generators and their parameter identification, energy savings of motor systems, and rare-earth permanent magnet motors.

Zhao Haisen

Zhao Haisen received his B.S.E.E. from Agriculture University of Hebei in 2004 and his Ph.D. from North China Electric Power University, Beijing, China, majoring in electric machines and apparatus. He is currently an associate professor at North China Electric Power University, Beijing, China. His research interests include the design of the premium motors, energy consumption analysis on electrical machines, and motor system energy-saving technology.