强流脉冲环境下的辐射干扰及抑制措施研究

发布时间：2018-01-06 22:26

本文关键词：强流脉冲环境下的辐射干扰及抑制措施研究　出处：《华中科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：电磁发射技术的发展日新月异，其机动性、灵敏性的提高等需要迫切要求其重要组成部分脉冲功率源向小型化、模块化的方向发展。而缩小脉冲功率源的体积大小虽然能提高模块的功率密度，却使模块在产生脉冲电流的过程中形成的强磁场对其自身影响更大。高频高压充电电源是电容式脉冲功率源的重要组成部分，它为初级能源提供充足的储能，其主要构成为串联谐振主电路、控制电路以及检测电路。其中，主电路由开关器件和磁性元件组成，实现电能的处理和变换；控制电路用来控制开关管、继电器的动作，以及给晶闸管触发信号；检测电路在充电过程中检测充电电压，电流，母线电压，电流瞬时值，在放电时记录电感电流波形。与脉冲功率源中的其它部分相比，这些电路均为弱电回路，易受干扰。本文主要研究脉冲电抗器产生的强脉冲磁场对弱电部分的干扰，具体研究内容如下: 首先,本文介绍了脉冲功率源的系统组成与工作流程，，简要分析了整个系统中可能存在的传导与辐射干扰源。并主要分析了作为系统自身辐射干扰源的脉冲形成网络（PFN）的工作原理，仿真得到PFN电路中晶闸管与电抗器上的电流波形，对晶闸管与电抗器上的电流波形作傅立叶变换，分析其频谱特性。其次，本文使用有限元数值分析软件Ansoft Maxwell对PFN回路中的电抗器进行了三维实体建模与电磁场仿真。为模拟正常工作时脉冲电流对脉冲功率源弱电部分的干扰，在简化的脉冲形成网络电路模型上加载脉冲电流来作为辐射干扰源。并利用该辐射干扰源模型研究了机壳内磁场强度在脉冲磁场下随空间、时间变化的趋势，为内部电路结构设计提供依据。然后，本文从切断电磁干扰路径的角度，探讨如何提高机壳保护敏感器件不受脉冲干扰源影响的能力。选择机壳内较靠近干扰源的一点的屏蔽效能SE为衡量指标，研究不同材质，厚度，开孔形状对矩形机箱屏蔽效能的影响。最后，利用有限元仿真的方法，计算得到机壳内位于不同平面的同一闭合回路上耦合到的感应电压。通过比较感应电压波形,得到了受干扰源影响最小的电路摆位方向。
[Abstract]:With the rapid development of electromagnetic emission technology, its mobility and sensitivity need to be miniaturized. The development of modularization. But reducing the volume of pulse power source can improve the power density of the module. The high frequency and high voltage charging power supply is an important part of capacitive pulse power source, which provides sufficient energy storage for primary energy. The main circuit consists of series resonance main circuit, control circuit and detection circuit. The control circuit is used to control the operation of the switch, the relay, and the trigger signal to the thyristor; The detection circuit detects the instantaneous values of charging voltage, current, bus voltage and current during charging. The inductance current waveform is recorded during discharge. Compared with other parts of the pulse power source, these circuits are all weak current circuits. The main contents of this paper are as follows: (1) the interference of the strong pulsed magnetic field produced by the pulse reactor to the weak part is studied in this paper. First of all, this paper introduces the system composition and work flow of the pulse power source. The possible conduction and radiation interference sources in the whole system are briefly analyzed, and the working principle of the pulse forming network (PFN), which is the system's own radiation interference source, is mainly analyzed. The current waveform of thyristor and reactor in PFN circuit is simulated. The current waveform on thyristor and reactor is analyzed by Fourier transform. Second. The finite element numerical analysis software Ansoft is used in this paper. In order to simulate the interference of pulse current to the weak part of the pulse power source, Maxwell has carried out the three-dimensional solid modeling and electromagnetic field simulation of the reactor in the PFN circuit in order to simulate the interference of the pulse current to the weak current part of the pulse power source during normal operation. The pulse current is loaded on the simplified pulse forming network circuit model to be used as the source of radiation interference. Using the model, the variation trend of magnetic field intensity in the shell with space and time under the pulse magnetic field is studied. Provides the basis for the internal circuit structure design. Then, from the point of view of cutting off the electromagnetic interference path. This paper discusses how to improve the ability of shell to protect sensitive devices from the influence of pulse interference source. The shielding efficiency SE of the point near the interference source in the shell is selected as the measurement index to study the different materials and thickness. The effect of opening shape on shielding efficiency of rectangular chassis. Finally, using finite element simulation method, the inductive voltage coupled to the same closed loop located in different plane in the shell is calculated, and the inductive voltage waveform is compared. The circuit pendulum direction which is least affected by the interference source is obtained.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN03;TN972

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