A Laboratory of Electromagnetic Compatibility for Power System

The first laboratory of electromagnetic compatibility in Chinais possessed of vivid characteristics in respect of design and configurationof testing equipment. It has successively completed some testing projectsand will unfold a more extensive range of measurement and test works inthe days to come.[

The Electromagnetic Compatibility and Distribution of Antenna System

The mathematical model of electromagnetic compatibility and the distribution of aircraft antenna system have been investigated. The solutions of the antenna gain and electromagnetic interference margin in the regions of low frequency, resonance and high frequency were discussed. By using the basic analytical method of the EMI margin the distributed antenna system can be determined. The main program flow chart of distributed antenna design were given, and illustrated with examples of the microstrip antennas.

Combination of Metal Shielding and Distance Estimation for Electromagnetic Compatibility Guarantee

In this paper, a solution for electromagnetic compatibility guarantee based on the combination of metal shielding and circuit components distance estimation methods is presented. The electromagnetic noises generated from a working radio-electronic unit can expand into the space and act on other around radio-electronic units. An EMC guaranteed radio-electronic unit by the suitable technique method will not cause the electromagnetic noise to others. In opposition, it will not be under electromagnetic action from another one. Due to the power of electromagnetic noise, the metal shielding, distance estimation or other technique methods should be used to guarantee EMC. Every method has own advantage as so as weakness for detail radio-electronic unit, so it is necessary to choose a suitable method to guarantee EMC for them, the combination of metal shielding and distance estimation is a choice, for example. The proposed solution has been evaluated by using CST (Computer Simulation Technology) software and EMxpertEHX analyzer in oscillator circuit context. The simulated results on CST show that the proposed solution decreases the electromagnetic radiation about of 39.1 dB at frequency 500 MHz in comparison to results when nothing electromagnetic compatibility methods are not used. The experimental results on the oscillator circuit are presented. The electromagnetic radiation reduction of the oscillator circuit is about of (25 - 30) dB. In comparison to individual metal shielding and distance estimation methods, the effectiveness of the proposed solution for electromagnetic compatibility guarantee is significantly increased.

Electromagnetic Compatibility Design for Powertrain Control Module

In order to improve the electromagnetic compatibility of powertrain control module （PCM）, a system procedure of vehicular PCM electromagnetic alteration is presented in this paper. First of all, the box of the PCM is divided into different cabins to eliminate interferences between power supply circuit, analog circuit and digital circuit. Secondly, the working principle and electromagnetic （EM） characters of all the signals adopted by a typical PCM are analyzed. Then according to specific electromagnetic characters, different measures are adopted in corresponding signal process circuits or signal transfer cables, such as ground layout designing, power supply protecting, signal shielding and drive cable interference suppressing. Finally, further improvement may also needed regarding to practical electromagnetic compatibility test effects. The final test shows that, with all the measures mentioned above, the conducted emission of a PCM can be reduced by 20 dB; meanwhile, the radiated emission can be reduced by 30 dB comparing to the original system.

Analysis of Reflectivity and Shielding Effectiveness of Absorbing Material–Conductor Laminate for Electromagnetic Compatibility

An absorbing material–conductor laminate is widely used for electromagnetic compatibility of electronic circuits at microwave frequencies. Such a laminate when properly designed will exhibit good results in terms of electromagnetic interference and compatibility. In this paper, microwave absorbing materials like 1) Ca-NiTi hexa ferrite composites (Ca (NiTi)x Fe12-2xO19) for x = 0.4, 2) M-Type Barium ferrites (BaFe12-2xAxCoxO19 for the tetravalent A ions, Ru4+ is chosen), 3) MnZn ferrite-Rubber composites with volume fraction vf = 0.4, 4) Carbonyl-Iron particle composites with volume fraction vf = 40% and conducting materials like copper, stainless steel are considered to form the interface in the laminate. Mathematical formulations are carried out for the estimation of reflectivity and shielding effectiveness of absorbing material–conductor laminate at microwave frequencies Analysis is also carried out for various thicknesses of the microwave absorbing material and conducting material in the laminate. The reflectivity and shielding effectiveness depends not only on the type of the selected material in the laminate, but also their thickness in the laminate and frequency of operation.

The Electromagnetic Compatibility Design of the Wireless Sensor Network Node

This paper is concerned with the sensor nodes’ hardware design of the wireless sensor network.We focus on the electromagnetic compatibility design of the printed circuit board.In this paper,we will give a schematic diagram first,and then,according to the layout,wiring rules and the knowledge of electromagnetic compatibility, we will present the design of the printed circuit board which has a good characteristic of electromagnetic compatibility.

Electromagnetic Compatibility Analysis of High-Power Pulse Drive Source

Due to the widespread application in recent years, high-power pulse sources have received special attention from large companies and R & D institutions around the world. Compared with foreign mid-range and high-end products, China’s development in this field is relatively lagging behind and lacks mature mid-range and high-end products. The reason is not only because of lack of theoretical support, but more importantly, in the pursuit of indicators and design, the electromagnetic compatibility of the equipment has not been studied thoroughly, resulting in a large degree of distortion in the output waveform, resulting in a reduction in actual value. This paper introduces the sources of high-power pulsed electromagnetic interference of the main driving source, conducts a reasonable high-power electromagnetic compatibility driving source dynamic analysis, and proposes measures to improve electromagnetic compatibility.

Electromagnetic Compatibility Technology of Electric Vehicles and Its Development Trend

The electromagnetic compatibility of electric vehicles is not only the important technology issue in researches,development and industrialization of electric vehicles,but also the key research area of ISO.In this paper,both national and international standards of electromagnetic compatibility of electric vehicles are analyzed;it is also suggested that our standards of electromagnetic compatibility of electric vehicles be improved from several aspects such as testing items,test procedures,limit value,etc.The electromagnetic environment of electric vehicles is analyzed in terms of interfering sources,providing the solutions to electromagnetic compatibility and measures of reducing electromagnetic interference.Advanced equipments introduced into Chinese electromagnetic compatibility testing laboratories accelerate the pace of the researches on related technologies and standards;China will develop the standards system which covers from the complete electric vehicle to the key components,promote the technology improvement and industrialization work of Chinese electric vehicles,transform the latest achievements and advanced experiences of Chinese electric vehicles industry to the related standards and contribute the development of international standards.

Annual Work Report of Electrical Engineering and Electromagnetic Compatibility Group in 2019

The group of Electrical Engineering and Electromagnetic Compatibility undertakes the design of AC power distribution system along with electromagnetic compatibility and integrated wiring in Heavy-ion Accelerator Facilities.

Study of Electromagnetic Compatibility in Hospital Environments

This paper presents a study on the effects of radiation from electronic equipment in hospitals. This study was performed in Argentinean, Colombian and Spanish hospitals. The work consists of two parts: a survey to determine the hospital personnel’s knowledge of the problem and a technical part consisting of a measurements campaign to determine the levels of radiated electrical and magnetic fields in several hospitals due to the presence of electromagnetic interferences, such as the use of mobile phones. The study of this problem has been of special interest in countries such as the USA and Canada, and this paper attempts to convey the necessity of creating regulations that can be applied to the hospitals of the countries analyzed. More than fifty hospitals were studied in these three countries, considering the following aspects: the hospital personnel’s awareness of the problem, whether the hospitals have performed previous studies of this type, the appearance of problems in medical equipment due to this interference, the origin of the interference, and the failures that have appeared in computers due to electromagnetic interference. The results show that, most hospitals have a lack of knowledge regarding this issue and that field levels above those allowed by international regulations are present. Therefore, a regulation must be established to avoid the problem.

高灵敏微波载荷卫星出舱电缆及舱体屏蔽的EMC设计

针对高灵敏微波载荷卫星对舱板电磁屏蔽效能的高需求与出舱电缆对舱体屏蔽效能巨大破坏性之间的矛盾,文章首先提出航天器理想舱板(无出舱电缆)的电磁屏蔽效能分析方法,给出提高对于1 GHz以上干扰电磁波屏蔽效能的设计原则;然后分析出舱电缆成为影响航天器外舱板对P波段(150 MHz~1 GHz)电磁波屏蔽效能主要因素的机理,给出干扰电流与干扰场强关系计算公式;最后给出出舱电缆及舱体屏蔽的电磁兼容(EMC)设计方法,提出用接地电阻测量法验证出舱电缆屏蔽皮接地的有效性,为总体总装EMC实施找到关键控制手段,并通过整星试验数据确认此方法能有效提升整星EMC试验效率。

Study of Electromagnetism Compatibility of Single-chip Switching Power Supply and Suppression Technique

As for the Domino effect dv/dt and electromagnetic interference during the rapid switching course of single-chip switching power supply,this article firstly analyzes electromagnetic interference source,and then diagnoses the essential interaction relationship between interference and switching activity based on the timely and area measured waveform,analyzes and studies the production mechanism and coupling path of interference mode,and sets up circuit model according to the features of transverse mode interference and common mode interference.Put forward different suppression methods finally.

Analysis and Simulation of the Influence of Electromagnetic Fields on Living Beings near HV Power Lines Using the FDTD Method

Recent decades have seen rapid advances in the field of electrical engineering, such that our environment has become a sea of electrical and magnetic signals, raising questions about the possible effects of low-frequency electromagnetic fields on the environment and which are capable of modifying and destroying our ecosystem. Particular interest was given in this article due to a massive influx of population living near high voltage lines. The analysis and simulation of the influence of low frequency electromagnetic fields on living beings in the vicinity of high voltage sources 132 kV and 220 kV in urban areas in DR Congo is the subject of our research with a view to estimating the level of exposure of humans to low frequency electromagnetic fields. To carry out our research, we used the classic method of analyzing the field produced near a high voltage line based on Maxwell’s image theory, the Maxwell-Gauss theorem and Maxwell-Ampère theorem to model and quantify low-frequency electromagnetic fields in the vicinity of high-voltage lines. The 2D FDTD numerical formulation was developed from telegraphers’ equations and allowed us to obtain models of current and voltage induced by electromagnetic fields on living beings below and near HV lines. The different simulations carried out on the proposed models illustrate the effects of the electrical and geometric parameters of the pylons on the distribution of the electromagnetic field in the vicinity of the HV lines. The results obtained were compared to the safety limits recommended by the standards.

基于EMC的AGV机械手的机箱结构设计研究

随着电子科学技术的快速发展,电子机箱面临着复杂的电磁场工作环境,为保证电子元器件在电磁场环境下稳定运行,电磁兼容(EMC)技术成为解决这一问题的措施,电磁兼容的重点是屏蔽结构设计,本文介绍了基于电磁兼容技术的电子机箱屏蔽结构的设计原则与流程,并以AGV机械手内部电子器件受到电磁干扰为例,设计一款电子机箱,通过试验验证了在在50-200MHz频段扫描时,屏蔽效能达到40dB及以上,通过本例可成为其他机箱的屏蔽结构设计的借鉴,具有重要的参考意义。

电驱动穿墙带载EMC试验系统设计及性能优化

带载电磁兼容(electromagnetic compatibility,EMC)试验系统是测试新能源汽车电驱动系统电磁干扰(electromagnetic interference,EMI)性能的重要设备。为优化我国自主研发带载电磁兼容试验系统,推动电驱动系统电磁干扰特性研究,本文优先自主研发了能够完全满足CISPR 25—2016测试标准的电驱穿墙带载电磁兼容试验系统。通过对电磁兼容试验的需求进行分析,提出了电磁兼容试验系统设计方案。然后,建立电磁兼容试验系统三维模型,并进行电磁学仿真,同时对系统的干扰源、屏蔽完整性等进行分析,进而保障所设计系统的电磁兼容性。最后,通过搭建电磁兼容试验系统,基于底噪测试进行分析与优化,进一步提升了系统的准确性与可靠性。

阻抗不匹配对乘用车EMC传导发射测试结果的影响评估

在按GB/T 40428标准进行车辆沿AC电源线的射频传导发射测试时,根据GB/T 6113.402标准给出的影响电源端传导发射测试结果不确定度的因素包括接收机的读数变化,人工电源网络与接收机之间线缆的衰减,人工电源网络的电压分压系数,接收机的修正,人工电源网络电压分压系数频率内插,人工电源网络与接收机之间阻抗的失配,人工电源网络的阻抗不理想,电源骚扰影响和环境影响等。本文主要研究人工电源网络与接收机之间阻抗失配对车辆沿AC电源线的射频传导发射测试的结果影响。研究表明人工电源网络与接收机之间阻抗失配会对车辆沿AC电源线的射频传导发射测试结果造成很大影响,为提高测试结果的准确性,推荐在人工电源网络与接收机之间增加50 Ω阻抗匹配网络。

低压直流设备EMC试验中的谐振参数可调装置

低压直流设备电磁兼容(EMC)检测过程中,常因实验室供电链路发生谐振导致受试设备无法正常开机或启动某功能。研究分析发现,分别从受试设备电源模块、接口滤波电路等入手调节整个电路环路的相关参数,可解决谐振问题。通过理论计算并结合一定的仿真分析,提出一个不改动受试设备及实验室相关测量设备状态,仅通过常规方式改变供电电源接口链路参数的便捷式谐振参数可调装置。根据实际需要,装置可闭合不同开关以设置为不同的电路状态,达到改变主回路谐振点的目的。

基于仿真方法的EMC风险要素分析

详细介绍了电磁兼容风险要素,并以电器产品系统级的线束间串扰风险要素为研究对象,仿真分析了发射电缆注入单源干扰时,电缆间距、离地高度、电缆类型对接收电缆上串扰耦合的影响。仿真与理论结果相符,为电气产品系统级的电缆线束间电磁兼容风险评估值赋值,提供了有效的数据支撑,可缩短研发周期,降低产品研发成本。

大型设备EMC性能现场评估方法

大型设备由于尺寸过大或供电要求过高无法进入实验室进行电磁兼容(EMC)性能测试,目前大型设备无明确的EMC现场测试标准要求。文章阐述了电磁兼容风险评估技术的分析机理及EMC风险评估理想模型,介绍了EMC风险评估要素识别、分析及EMC风险评价方法。借助电磁兼容风险评估技术可评价大型设备的EMC性能,也有助于大型设备现场测试中发现问题后,借助EMC风险评估技术发现EMC风险点,提出相应的风险减缓措施,以提升大型设备的EMC性能。

Research on electromagnetic relay's dynamic characteristics disturbed by uniform static magnetic field

Electromagnetic relay is a widely used apparatus which usually works in a magnetic disturbance environment. To evaluate its electromagnetic compatibility (EMC) in a static magnetic field, dynamic characteristics of a clapper relay in a uniform static magnetic field situation based on the finite element method (FEM) is studied. Influences of the magnetic field on dynamic parameters (delay time, pick-up time, end pressure, and final velocity) as well as a situation in which the relay cannot function normally are analyzed. Simulation reveals that the external magnetic field which weakens the relay’s air-gap field has a greater influence on the relay’s dynamic parameters than the one strengthening the field. The validity of the simulation is verified by measured results of coil current and armature displacement.