基于向量拟合法的电感阻抗特性建模

Modeling of Inductors' Impedance Characteristic Based on Vector Fitting Method

功率变换器的高速开关动作会产生严重的传导电磁干扰噪声。EMI滤波器常用于减小传导电磁干扰噪声。电感器作为功率变换器和滤波器的主要电磁元件,其阻抗特性建模的准确性则显得尤为重要。采用向量拟合法提取电感阻抗参数,进而建立其高频等效电路模型,再通过阻抗测量,求取阻抗特性有理函数的一次项、常数项系数及零极点等参数。经电感实物的仿真与实测对比,证明了该方法的适用性,并在车载设备传导噪声要求频段内的拟合效果较好,模型精度较高。

Conducted electromagnetic interference （ EMI） noise is generated by power converters with high switching frequency. EMI filters are thus widely used to reduce these conducted noise. As the main electromagnetic component of power converters and EMI filters,the modeling of inductors’ impedance characteristic is very important. The vector fitting method was used to extract the impedance parameters of inductor, thus its high frequency equivalent circuit was modeled. Based on impedance measurement, a rational function approximation fitting algorithm was cooperated in this method. The rational function＇s one time term coefficient, the constant term coefficient, zero and pole are solved to extract the parameters in the model. The applicability of the method was proved by comparing the simulation result with the experimental result of a CM choke. It shows that this method is applicative and accurate in the frequency band of vehicle equipments＇ conducted noise requirements.