磁芯非线性磁化特性的精确表征是感应电压叠加器(induction voltage Adder,IVA)数值模拟的关键,由于IVA的激励脉冲前沿为几十纳秒,磁芯在快脉冲条件下的磁化特性难以直接通过实验测试。为此提出一种非晶夹膜磁芯逆J-A参数的预测方法,通过双绕组法测试不同脉冲频率下磁芯的磁滞回线,将磁芯的饱和磁感应强度、剩余磁感应强度、矫顽力、矫顽力点微分磁导率、饱和磁场强度作为磁滞回线的关键特征参数,实验控制磁芯励磁电流峰值保证磁芯的饱和点不变,并通过数值拟合得到剩余磁感应强度、矫顽力和矫顽力点微分磁导率与激励脉冲等值频率之间的关系,最后利用高频率下的特征参数绘制磁滞回线再进行逆J-A参数辨识。以磁滞回线的面积表征单位体积的磁芯能量损耗,实验测试了2组兆赫兹以上的磁滞回线,预测的磁滞回线与实测磁滞回线的磁芯能量损耗误差<3%,验证了此种方法的有效性,快脉冲激励下辨识得到的逆J-A参数可应用于IVA磁芯的非线性建模。
Abstract
Accurate characterization of the nonlinear magnetization characteristics of the magnetic core is crucial for numerical simulation of the induction voltage adder (IVA). The IVA’s excitation pulse has a rise time of tens of nanoseconds
thus the core’s magnetization characteristics under fast-pulse conditions are difficult to measure directly through experimental methods. In this paper
a prediction method for inverse J-A parameters of amorphous sandwiched core is proposed
the hysteresis loops of the core under different pulse frequencies are tested by the double-winding method;meanwhile
the saturation magnetic flux density
remanent magnetic induction
coercivity
differential permeability at coercive force point and saturation magnetic field strength are taken as the key characteristic parameters of the hysteresis loops
the experiment controls the peak excitation current to ensure the saturation point of the core remains unchanged
and the relationships between remanent magnetic induction
coercivity
differential permeability at coercive force point and excitation pulse equivalent frequency are obtained by numerical fitting. Finally
the characteristic parameters under high frequency are used to plot the hysteresis loops
followed by inverse J-A parameter identification. The volumetric core loss is characterized by the hysteresis loop area
and experimental tests are conducted on two sets of hysteresis loops above 1 MHz frequency. The results show that the error in core energy loss between the predicted and measured hysteresis loops is less than 3%
validating the effectiveness of this method. The inverse J-A parameter identified under fast-pulse excitation can be applied to the nonlinear modeling of IVA core.