DC-DC变换器的差模传导干扰耦合通道建模分析

Modeling of differential mode conducted interference coupling channel of a DC-DC converter

为了实现对电力电子装置差模传导干扰的系统化分析和预测,提出了一种基于系统辨识的方法,描述差模传导干扰耦合通道的特性。以Buck变换器为研究对象,在MOSFET元件漏源极之间加入伪随机信号(PRBS)作为系统输入信号,取电源侧的差模干扰作为输出信号,由提取的数据用最小二乘法辨识出耦合通道的系统模型。结果表明,由耦合通道模型预测的波形和实验波形时域波形吻合性较好,频域特性成分较一致。应用建立的模型通过测量MOSFET元件漏源极之间干扰电压为输入,即可预测电源侧传导干扰,所需测试电量较少,可得到较好的效果。

In order to implement the systematic analysis and prediction of differential mode conducted interference of power electronic devices, a method is proposed based on system identification to describe the characteristics of differential mode conducted interference coupling channel. This paper selects Buck converter as the research object, exerts Pseudo Random Signal （PBRS） between MOSFET drain-source as input signal and takes differential mode interference of power supply side as output signal. According to the extracted data, the system model of coupling channel is identified by the least square method. It is indicated that the experimental waveforms are consistent with the coupling channel model prediction results in terms of the time domain and frequency domain. Measuring the interference voltage between the drain-source of MOSFET as the input signal by use of the built model can predict the conducted interference of power supply side and achieve good results with the relative few measurements. This work is supported by National Key Research and Development Program of China （No. 2016YFC0600906）.