改进永磁饱和铁心型故障电流限制器及其等效电路模型

A Novel Saturated-Core Fault Current Limiter With Permanent Magnet Modules and Its Nonlinear Equivalent Circuit

提出了一种带有改进永磁模块的饱和铁心型故障电流限制器物理结构,并且给出其等效电路模型。使用永磁模块从多个方向对故障电流限制器的铁心进行激磁,显著提高了铁心内部的磁通密度,降低了对直流励磁电流的需求。同时,通过对故障电流限制器线圈之间磁通耦合关系的分析,以及使用有限元计算提取自感和互感参数,得到了故障电流限制器的非线性等效电路模型及其数值求解方法。实际制作了饱和铁心故障电流限制器试验模型,开展了相关的试验研究。试验结果表明,其限制线路短路电流效果十分显著,可以限制67.6%的短路电流峰值,及63.1%稳态短路电流有效值。且相对于不带永磁模块结构的故障电流限制器,可以减少93.75%的直流励磁电能消耗,在一定程度上解决了开环饱和铁心型故障电流限制器直流励磁的损耗问题。同时,通过试验结果与计算结果对比验证了等效电路的有效性。

In this paper,a saturated-core fault current limiter（FCL） with improved permanent magnet（PM） modules is proposed.A nonlinear equivalent electric circuit model of the saturated-core FCL is also provided.PM modules are used to excite magnetomotive force（MMF） for the cores from different directions and to increase magnetic flux density in the cores,thereby reducing demand for DC magnetizing current.By analyzing magnetic flux coupling between FCL coils and achieving parameters of self inductances and mutual inductances of the coils with finite element method,a nonlinear equivalent circuit model of FCL and its numerical solution method are obtained.A FCL test model is established and relative test is performed.Test results show that FCL structure has good fault current clipping ability：67.6% fault current peak and 63.1% steady-state fault current amplitude can be reduced with the FCL.Compared with FCL without PM modules,93.75% DC exciting power can be saved and energy loss in DC coils is reduced remarkably.Moreover,the nonlinear equivalent electric circuit model of the saturated-core FCL shows good accuracy confirmed with experimental results.