Simulation of Magnetic Saturation Characteristics of Pulse Transformer based on Inverse Jiles-Atherton Model

Recently, pulse transformers have been widely used in pulsed power systems. However, the magnetic saturation phenomenon of the pulse transformer with closed magnetic cores will change its output waveform parameters, which makes it difficult to predict the output waveforms of the pulse transformer accurately, and a more accurate model considering the nonlinear magnetization process of the pulse transformer needs to be established. In this article, the classical Jiles-Atherton (J-A) equations are modified to make it suitable for pulsed excitation, and the pulsed hysteresis loop of Fe-based Nanocrystalline (FE-N) cores is obtained using the dynamic testing circuit, which is combined with the Genetic Algorithm (GA) to achieve J-A parameter identification of the cores. Finally, the magnetic saturation characteristics and the output parameters of the pulse transformer are analyzed by the constructed field-circuit coupled simulation model. The results show that the model can simulate the influence of magnetic core saturation on the output waveforms, the maximum error of the pulse rise time is 3.33%, and the maximum error of the pulse amplitude is 6.26%. This indicates that the J-A parameters obtained by solving the modified J-A equation are more accurate, which is significant for the simulation modeling and design of pulse power components with magnetic cores.

近年来，脉冲变压器（pulse transformer）已广泛应用于脉冲功率系统（pulsed power systems）。然而，带闭合磁芯的脉冲变压器会因磁饱和（magnetic saturation）现象改变其输出波形参数，导致难以精准预测其输出波形，因此亟需建立考虑脉冲变压器非线性磁化过程（nonlinear magnetization process）的高精度模型。本文对经典的吉尔斯-阿瑟顿（Jiles-Atherton, J-A）方程进行修正，使其适配脉冲励磁（pulsed excitation）工况；通过动态测试电路（dynamic testing circuit）获取铁基纳米晶（Fe-based Nanocrystalline, FE-N）磁芯的脉冲磁滞回线（pulsed hysteresis loop），并结合遗传算法（Genetic Algorithm, GA）完成该磁芯的参数辨识（parameter identification）。最终，通过所构建的场路耦合仿真模型（field-circuit coupled simulation model），分析了脉冲变压器的磁饱和特性（magnetic saturation characteristics）与输出参数。结果表明，该模型可准确模拟磁芯饱和对输出波形的影响：脉冲上升时间（pulse rise time）的最大误差为3.33%，脉冲幅值（pulse amplitude）的最大误差为6.26%。这说明通过修正后的J-A方程求解得到的J-A参数精度更高，对带磁芯脉冲功率元件（pulse power components）的仿真建模与设计具有重要的指导意义。