考虑漏磁效应的永磁饱和型故障限流器磁路建模与实验研究

漏磁效应对永磁饱和型故障限流器(permanent-magnet-biased saturation based fault current limiter,PMFCL)的动态特性具有重要影响。针对一种直线式PMFCL的磁拓扑,以铁心磁通的工作零点作为分界阐明了其2个阶段的限流机理,指出铁心磁通自过零反向后将发生畸变,永磁体不再参与限流过程。基于磁场分割原理实现2类等效磁路模型中总漏磁导和漏磁系数的计算,针对拟圆环截面磁通管的漏磁导,提出基于曲线拟合而改变积分变量的求解方法。在Matlab/Simulink环境下建立了考虑漏磁效应的PMFCL仿真模型,分别与小电流和大电流工况的实验结果进行对比,验证了建模方法的有效性。

Magnetic Topology Modeling and Experimental Study of Permanent-magnet-biased Saturation Based Fault Current Limiter With Leakage Flux Effect

Leakage flux renders significant impacts on dynamic performance of the permanent-magnet-biased saturation based fault current limiter(PMFCL).A straight-line type PMFCL topology was employed to analyze the current limiting mechanism during the two interim stages for which a cut-off boundary of zero magnetic flux of the iron-core was adopted.After the magnetic flux in the iron-core crosses zero and reverses its direction,flux distortion will emerge in the iron-core and the permanent magnet will no longer be involved in the current limiting process.The overall leakage permeances as well as the leakage coefficients were achieved through magnetic field partition scheme,and two corresponding equivalent magnetic circuit models were further established.A numerical solution for leakage permeance of the flux tube with quasi-torus cross section was proposed with curve fitting method as to change the integral variables.Simulation models for PMFCL including leakage flux effects were established with MATLAB/SIMULINK,and the results were compared with that of experimental studies for both small current and large current cases,which verified the effectiveness of the modeling methodology.