College of Electrical Engineering,Zhejiang University
State Power Corporation of China
The converter grid-connected system in a weak grid faces the potential risk of sub-super-synchronous oscillation. The stability criterion based on the generalized impedance considers the coupling effect between grid and the converter in sub-super-synchronous band, and can transform the system stability analysis into a single-input-single-output system. Injecting disturbances in secondary side can not only measure the generalized impedance of the converter, but also has the advantages of low cost and easy operation compared with the measurement by injecting disturbances in primary side. To this end, a method for measuring the generalized impedance of converter in secondary side in super-synchronous band at an arbitrary power factor is proposed. Firstly, we derive the system"s generalized impedance and primary-dual complex circuit considering the perturbation at secondary system. Then, the principle of measurement is explained from the point of view of circuit. Finally, we propose the measuring method of converters" generalized impedance at all power factor in sub-super synchronous band. The proposed method is a generalization of the existing generalized impedance measurement method. Simulation results verify the proposed method.
WAN Wei,YUAN Hui,WANG Guanzhong,et al.Measurement Method for Generalized impedance of Converter Based on Perturbation in Secondary Side in Sub- and Super-Synchronous Band[J/OL].Automation of Electric Power Systems,http://doi.org/10.7500/AEPS20200109008.