Effect of CT transient characteristics on transfer of inrush

The Journal of Engineering

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[1] Power Dispatching Control Center of Guangdong Power Grid, Guangzhou, People's Republic of China;State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China;Hubei Electric Power Security and High Efficiency Key Laboratory, Huazhong University of Science and Technology, Wuhan, People's Republic of China;

关键词: power transformer protection;    transformer cores;    ferromagnetic materials;    current transformers;    transformer core;    CT transfer;    differential protection;    CT transient characteristics;    multiple misoperation accidents;    power components;    adjacent transmission lines;    power grid;    electromagnetic transient interaction;    simulation Lucas model;    industrial practical CT;    malfunction analysis;    inrush transfer period;    transformer transient inrush current process;    inrush current second harmonic proportion;    P-PR;    multiple nonlinear ferromagnetic components;   

DOI  :  10.1049/joe.2018.8441

来源: publisher

【 摘 要 】

During the inrush period, multiple misoperation accidents of differential protection of transformers happened, which seriously threatened the safe and stable operation of power grid. In the traditional malfunction analysis, only the inrush current process is considered, and the electromagnetic transient interaction between the transformer and other non-linear ferromagnetic components such as CT is hardly considered. Here, the variation rule of inrush current waveform characteristic is analysed, and the influence rule of secondary load and type of CT on inrush current second harmonic proportion and dead angle is simulated by using the simulation Lucas model of industrial practical CT (P/PR). The results show that the second harmonic proportion of the inrush current and the dead angle of the waveform depend on the saturation angle of the transformer core. The larger the saturation angle is, the smaller the second harmonic proportion is, and the larger the dead angle of the waveform is. The second harmonic proportion of the inrush current becomes larger, and the dead angle of sympathetic inrush becomes smaller after CT transfer. The dead angle of magnetising inrush waveform depends on the secondary load resistance. It may increase or decrease..

【 授权许可】

CC BY