摘要
电磁暂态仿真中,减小仿真步长可有效抑制非线性变压器仿真过冲失真问题,但大容量变压器的励磁涌流过程往往衰减缓慢,势必会造成仿真效率低,使得仿真时间明显增加。该文建立了一种含有非线性励磁支路的大容量变压器动态相量多尺度电磁暂态模型,并提出一种动态相量磁链预测方法,通过不同仿真步长对磁链和电流进行精准预测和仿真,解决了分段线性化在大步长下出现的过冲失真问题,实现了励磁涌流宽频特征下依旧可以在不牺牲较多谐波的情况下采用大步长仿真的功能。当励磁涌流刚发生时,磁链动态相量变化较大,利用较小仿真步长对磁链进行预测,从而根据电流-磁链曲线拟合关系求得励磁涌流;当检测到磁链频谱集中在工频附近时,磁链的动态相量形式将保持恒定,采用大仿真步长预测磁链,从而根据电流-磁链关系求得准确的励磁电流,在采用大步长的同时解决了过冲失真问题,增加了仿真的计算效率。最后的仿真结果验证了该文提出的变压器模型及动态相量预测法的正确性和有效性。
The overshoot problem can be avoided by adopting small time step in electromagnetic simulations, and the inrush current of a large capacity transformer usually decays very slowly which will certainly results in low simulation efficiency. In this paper, an augmented dynamic phasor multitimescale electromagnetic transient model was established for large-capacity transformer with nonlinear excitation branch, and a dynamic phasor flux prediction method was utilized. The current can be accurately predicted and simulated, which solves the overshoot problem of piecewise linearization under large time steps, and large time steps can be adopted without sacrificing more current harmonic components. When the inrush current occurred, a small-time step was adopted to predict the flux linkage,then magnetizing inrush current was obtained by current-flux curve fitting function. When the flux linkage spectrum was detected concentrated near the fundamental frequency, the flux linkage waveform will maintain its sinusoidal characteristics then a large time step can be adopted without sacrifice of simulation accuracy. In this way, the accurate inrush current was simulated utilizing current-flux curve fitting function, and the overshoot problem was solved using large step size to accelerate the simulation speed. Finally, the simulation results verified the correctness of the proposed transformer model and dynamic phasor prediction method.
作者
龚振
刘承锡
姚良忠
杨波
庄俊
黄晓辉
Gong Zhen;Liu Chengxi;Yao Liangzhong;Yang Bo;Zhuang Jun;Huang Xiaohui(School of Electrical Engineering and Automation Wuhan University, Wuhan 430027 China;China Electric Power Research Institute ,Nanjing 210003 China;Nanjing Hexi Electric Co.Ltd, Nanjing 210008 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2022年第15期3805-3817,共13页
Transactions of China Electrotechnical Society
基金
国家自然科学基金资助项目(52007133)。
关键词
动态相量预测法
励磁涌流
非线性
过冲现象
Dynamic phasor prediction method
inrush current
nonlinear
overshoot
