1.College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China;2.Northwest Branch of State Grid Corporation of China, Xi’an 710048, China;3.China Electric Power Research Institute, Beijing 100192, China
The interaction between static var generator (SVG) and renewable energy equipment becomes obvious in weak grids, and it is a difficult problem to analyze the oscillation characteristics of multi-infeed system with renewable energy and SVGs. To deal with this issue, a system dynamic model with unified operation of SVG and renewable energy which can preserve the network structure is established. Also, a generalized short-circuit ratio calculation method for multi-infeed system with renewable energy considering SVG effect is proposed to judge whether the system is stable and to quantify the stability margin of the system. Firstly, the system transfer function matrix and characteristic equation of the network structure preserving model are derived. Then, based on the modal perturbation theory, an equivalent homogeneous multi-infeed system which approximates the dominant characteristics of the system is constructed. And it is strictly proved that the generalized short-circuit ratio can be used to analyze the oscillation stability margin of multi-infeed system with renewable energy and SVGs. Finally, the calculation method of generalized short-circuit ratio and its critical value in multi-infeed system with renewable energy considering SVG effect is given. Besides, the quantitative method of the power grid strength and system oscillation stability margin is presented. The simulation results verify the validity of the proposed analysis and calculation method.
This work is supported by State Grid Corporation of China (No. 5100-202055005A-0-0-00).
|||YUAN Hui, XIN Huanhai, WANG Guanzhong, et al. Analysis on Oscillation of Multi-infeed System with Renewable Energy and Static Var Generator and Calculation of Its Generalized Short-circuit Ratio[J]. Automation of Electric Power Systems,2021,45(14):38-46. DOI:10.7500/AEPS20200826008|