硅钢片铁心的宽频动态电路仿真模型

A Broadband Dynamic Circuit Simulation Model of Laminated Core of Silicon Steel Sheets

对硅钢片铁心进行准确的宽频建模,是实现对含铁心的电气设备及其系统精确分析的关键所在。然而,由于铁心饱和及集肤效应,使得铁心的某些参数随激磁电压频率的变化而变化,导致铁心在高频下的建模尤其困难。针对这一问题,鉴于铁心内每片硅钢片的磁场分布规律基本相同,提出一种基于等效电路法的硅钢片铁心宽频动态模型。即对硅钢片合理剖分后,铁心等效为一个梯形电路,此电路可按照一定的规则与外电路相连,从而实现整个系统的分析和计算。本文优化了等效电路法中硅钢片的剖分原则,对于工作带宽在0.05~40k Hz之内的电路,铁心可由不超过3阶的梯形电路等效。采用改进郎之万函数和剂量–效应函数分别拟合磁化曲线和非线性电感,能够快速获得电感值用于模型仿真计算。最后,通过高频振荡试验及工频试验验证了文中所提铁心宽频电路模型的正确性与有效性。

It is a key step in the analysis of electrical equipment and systems which contain laminated cores to build accurate model of laminated core of silicon steel sheets. However, due to the influences of saturation of iron core and skin effect, some parameters of core change over frequency of the excitation voltage, which results in establishing model of the core in high-frequency especially hard. Considering the distribution of magnetic field in each silicon steel sheet of the core is basically same, a broadband dynamic model of laminated core based on equivalent circuit method was put forward. In detail, the laminated core can be equivalent to a trapezoidal circuit after reasonable subdivision of silicon steel sheet, which can be connected with external circuit according to certain rules, so analysis and calculation of the whole system can be implemented. The subdivision principle of silicon steel sheet in equivalent circuit method was optimized, namely, the laminated core can be equivalent to a trapezoidal equivalent circuit no more than 3 levels within the bandwidth of 0.05~40kHz. By adopting modified Langevin function and dose-response function to fit magnetization curve and nonlinear inductance respectively, the inductance can be obtained quickly which was used in simulation and calculation of the model. Finally, high-frequency and power-frequency experiments were implemented to verify the correctness and validity of the model proposed. © 2016 Chin. Soc. for Elec. Eng.