【作者】 王杰；

【导师】 杜平安；

【作者基本信息】 电子科技大学 ， 机械工程， 2020， 硕士

【摘要】 电子设备的不断进步及广泛应用使得空间人为造成的电磁能量持续增长,大量电磁噪声以电磁场形式在空间传播,电磁环境日益复杂。为保证电子设备能在复杂电磁环境中正常运行,必须提高设备自身的抗电磁干扰水平,也就是发展和完善电磁干扰抑制技术。本文以实际工程中的高压放电系统为研究对象,对高压放电系统传导电磁干扰的建模及其滤波抑制方法进行了研究,主要内容如下:(1)高压放电系统仿真模型的建立及电磁干扰的分析与确定。首先对系统的部件组成以及工作原理进行了介绍。接着结合电磁兼容三要素,分析并确定了系统电磁干扰的产生机理。然后根据系统结构特点与工作原理,结合各仿真软件的算法特点与适用范围,选取了CST作为本研究中的仿真软件,并对系统的场线路耦合仿真模型进行了建立。最后启动场线路协同仿真耦合计算,得出了系统中的辐射及传导EMI,确认了地线串扰传导EMI是该系统中的主要电磁干扰,并分析了地线串扰对电路产生干扰的影响作用机理,同时结合系统工作中的实际情况,选取了电源转换电路作为系统仿真中的受扰电路进行研究。(2)二极管SPICE模型建立方法研究及受扰电路的搭建、仿真与分析。对二极管SPICE模型的建立方法进行了研究,对SPICE仿真器及SPICE模型进行了详细分析,研究了建立二极管SPICE模型所需要的模型参数,然后以型号为2CZ106的快恢复整流二极管为例,详细说明了二极管SPICE模型的建立方法及步骤,并建立得出了2CZ106的SPICE模型,将其应用到了受扰电路的搭建中,完成了受扰电路的搭建,最后对受扰电路在电磁干扰影响下的工作状态进行了仿真分析。(3)传导电磁干扰滤波抑制方法研究。提出了一种基于电容频率特性的传导电磁干扰滤波方法。介绍了电容频率特性,分析了电容在滤波电路中的工作原理。最后将电容的频率特性与滤波原理相结合,提出了一种准确的滤波方法:即首先对所提取的串扰信号实施傅里叶变换,获取该串扰信号的能量分布频谱图;然后根据该图对干扰信号的能量分布进行分析,找到主要频率点;最后通过电容阻抗计算公式,推导计算出最佳滤波电容值。仿真结果表明,该方法具有较好的滤波效果,干扰信号得到有效抑制。更多还原

【Abstract】 The continuous advancement and wide application of electronic equipment has made the artificial electromagnetic energy caused by space continue to increase.A lot of electromagnetic noise propagates in space in the form of electromagnetic fields,and the electromagnetic environment is becoming more and more complicated.In order to ensure the normal operation of electronic equipment in a complex electromagnetic environment,it is necessary to improve the level of anti-electromagnetic interference of the equipment itself,that is,to develop and improve electromagnetic interference suppression technology.This article takes the high-pressure discharge system in the actual project as the research object,and studies the modeling and filtering suppression method of the conducted electromagnetic interference of the high-pressure discharge system.The main contents are as follows:(1)Establishment of simulation model of high-voltage discharge system and analysis and determination of electromagnetic interference.First,the components of the system and the working principle are introduced.Then combined with the three elements of electromagnetic compatibility,the mechanism of electromagnetic interference in the system is analyzed and determined.Then according to the system structure characteristics and working principle,combined with the algorithm characteristics and application scope of each simulation software,CST was selected as the simulation software in this study,and the field line coupling simulation model of the system was established.Finally,the coupling calculation of the field line co-simulation was started,and the radiated and conducted EMI in the system was obtained.It was confirmed that the ground crosstalk conducted EMI is the main electromagnetic interference in the system,and the mechanism of the effect of the ground crosstalk on the circuit interference was analyzed.At the same time,combined with the actual situation of the system,the power conversion circuit was selected as the disturbed circuit in the system simulation.(2)Research on the establishment of diode SPICE model and construction,simulation and analysis of disturbed circuits.The method of establishing the diode SPICE model is studied,the SPICE simulator and the SPICE model are introduced in detail,the model parameters required to establish the diode SPICE model are analyzed,and then a fast recovery rectifier diode of type 2CZ106 is taken as an example.The establishment method and steps of diode SPICE model are introduced,and the SPICE model of 2CZ106 is established.It is applied to the construction of the disturbed circuit,the construction of the disturbed circuit is completed,and finally the affected circuit is affected by electromagnetic interference.The working status was simulated and analyzed.(3)Research on suppression methods of conducted electromagnetic interference filtering.A filtering method for conducted electromagnetic interference based on the frequency characteristics of capacitance is proposed.The frequency characteristics of the capacitor are introduced,and the working principle of the capacitor in the filter circuit is analyzed.Finally,combining the frequency characteristics of the capacitor with the filtering principle,an accurate filtering method is proposed,that is: first the Fourier transform is performed on the extracted crosstalk signal to obtain the energy distribution spectrum diagram of the crosstalk signal;then according to the figure The energy distribution of the interference signal is analyzed to find the main frequency point;finally,the optimal filtering capacitor value is derived through the calculation formula of the capacitor impedance.The simulation results show that the method has good filtering effect and the interference signal is effectively suppressed.更多还原