Discussion on dynamic reliability tolerance design technology of electromagnetic relay

Reliability tolerance design of electromagnetic relay during its design period plays an essential role in guaranteeing the consistencies of reliability and output characteristic. The reliability tolerance design can ensure that the products would work well under the influence of disturbing factors (including internal interference, external interference, and machining dispersion). Com- pared with static characteristic, dynamic characteristic of electromagnetic relay can describe its operating process better. This article researches influence of the three kinds of disturbing factors on the dynamic characteristic of electromagnetic relay based on calculating dynamic characteristic. Then, the dynamic reliability tolerance design method of electromagnetic relay is discussed considering three kinds of disturbing factors. Conclusions reached can help to assure the reliability of electromagnetic relay from the beginning of design.

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.

Influence of the ambient air temperature on the electrical contact reliability of electromagnetic relay

The dynamic contact resistances of HH52P electromagnetic relays are measured under different ambient air tem- perature. Their diagnostic parameters are extracted and determined. It is found that the ambient air temperature obviously influ- ences some parameters. In order to research its influence on the electrical contact reliability of electromagnetic relay, the statistic analysis is applied to study the static contact resistance, the max of the dynamic contact resistance and the bounce time. It is found that the ambient air temperature regularly influences the three parameters. Thoroughly, the phenomenon is studied and analyzed in the point of material science so as to probe into the essential matter of it.

Optimization design method of contact bounce and breakaway initial velocity for aerospace electromagnetic relay

Aerospace electromagnetic relay is an electric component that has been widely used in aerospace industry.Contact bounce and contact breakaway for initial velocity are the key parameters that have strong influence on reliability and electric life of the relay.Generally,it is difficult to optimize these two parameters simultaneously.In this paper,according to kinetics theory and structural mechanics,a dynamic reaction calculation model of the relay that describes contact bounce and breakaway for initial velocity is proposed.Under the constraints of contact gap and contact force,the optimal combination of debugging parameters is obtained by the application of orthogonal design.It considers the reduction of contact bounce and the augmentation of breakaway for initial velocity as the optimization objectives,and takes the debugging parameters as the optimization variables.All these above ensure the increase of contact breakaway for initial velocity and the decrease of contact bounce simultaneously,and contact arc erosion is also reduced.

An electromagnetic view of relay time in propagation of neural signals

We review the experimental and computational data about the propagation of neural signals in myelinated axons in mice,cats,rabbits,and frogs published in the past five decades.In contrast to the natural assumption that neural signals occur one by one in time and in space,we figure out that neural signals are highly overlapped in time between neighboring nodes.This phenomenon was occasionally illustrated in some early reports,but seemed to have been overlooked for some time.The shift in time between two successive neural signals from neighboring nodes,defined as relay timeτ,was calculated to be only 16.3μs-87.0μs,i.e.,0.8%-4.4%of the average duration of an action potential peak(roughly 2 ms).We present a clearer picture of the exact physical process about how the information transmits along a myelinated axon,rather than a whole action potential peak,what is transmitted is only a rising electric field caused by transmembrane ion flows.Here in the paper,τrepresents the waiting time until the neighboring node senses an attenuated electric field reaching the threshold to trigger the open state.The mechanisms addressed in this work have the potential to be universal,and may hold clues to revealing the exact triggering processes of voltage-gated ion channels and various brain functions.

Method of analyzing vibration characteristics of armature system of hermetically sealed electromagnetic relay

Published research is minimal on vibration characteristics of hermetically sealed electromagnetic relay (EMR) ex- posed to mechanical environment. The vibration characteristics of armature system, link contact system with electromagnetic system will cause EMR malfunction. The nonlinear dynamics model of armature systems was studied by considering electro- magnetic attraction force and opposite mechanical force in this paper. Angular displacements of armature under different sinu- soidal vibration conditions are solved in order to obtain the failure mode result from armature system. Vibration tests showed the presented analyzing method is suitable for EMR. The conclusions are instructive for increasing vibration resistance of armature systems of EMR, and are significant for reliability design of switch apparatus.

Damage evolution law of coal-rock under uniaxial compression based on the electromagnetic radiation characteristics

Based on electromagnetic radiation characteristics, the present research studied the damage evolution of rock under uniaxial compression. Besides, this research built the coal-rock damage evolution model considered residual strength. The applicability and accuracy of the model were verified through experiments. The results show that coal-rock damage evolution consists of four periods. The first period is from the beginning of compression to nearly 20% of the stress peak value, during which the damage variable changes stably about 0.1, and accordingly a few of electromagnetic radiation signals emerge. The second period is from about 20% to 70% of the stress peak value. The damage has stable development, and the parameter of electromagnetic radiation characteristics turns larger continuously with the increase of stress. The third period is when the damage has accelerated development, the coal-rock was broken which result from sharp increasing of the damage variable, meanwhile a great quantity of electromagnetic radiation signals emerge. The fourth period is after the coal-rock fracture, during which the damage variable corresponding to the parameter of electromagnetic radiation characteristics has a stable development. This research has great academic and realistic significance for further studies the electromagnetic radiation characteristics of coal-rock under loading and damage and the forecasting of coal-rock dynamic disasters.

Effect of rock mechanical properties on electromagnetic radiation mechanism of rock fracturing

The influence of rock mechanical properties on the electromagnetic radiation(EMR)mechanism of rock fracturing is an important research topic in solid mechanics and earthquake prediction.In this study,an EMR model of rock fracturing considering the fracture factor,elastic modulus,Poisson’s ratio,radiation distance and crack length is derived based on the Hertz oscillator array assumption.An experimental system,including an electromagnetic shielding module,an EMR signal induction and transmission module,a signal recording module and a loading module,is developed to understand the EMR characteristics of four different rocks.The validity of the EMR theoretical model is verified and the relationships between the rock cracking morphology and the EMR waveform,amplitude and frequency are revealed.It is found that rock mechanical properties have obvious influences on the EMR waveform,amplitude and frequency during rock fracturing.This study provides a better understanding on the EMR mechanism of rock fracturing and can help to improve the accuracy of rock disaster prediction based on EMR.

Electromagnetic radiation early warning criterion of rock burst based on statistical theory

Rock bursts are serious natural disasters encountered worldwide in coal mining and rock engineering.In order to forecast rock bursts more effectively,a new rock burst forecasting index E,consisting of intensity and the number of pulses,is proposed,on the basis of abnormal characteristic symptoms of electromagnetic radiation(EMR) generated before rock bursts,combined with statistical theory.The index is distributed as a χ2 distribution with 2 degrees of freedom,i.e.,E～χ 2(2).Via this index,a quantitative comprehensive forecasting criterion of EMR was initially established.E values were calculated when the occurrence probability of the occurrence of a rock burst was 50%,70% and 90%.Appropriate measures should be taken when using these values on the scene.Using EMR data collected in the Nanshan Mine of the Hegang mining area,we verified that the analytical result were consistent with actual situations.This index is of theoretical importance and as a reference for forecasting rock bursts in coal mines.

Study of electromagnetic characteristics of stress distribution and sudden changes in the mining of gob-surrounded coal face

The incidence of dynamic coal or rock disasters is closely related to the distribution of stress in the surrounding rock. Our experiments show that electromagnetic radiation (EMR) signals are related to the state of stress of a coal body. The higher the stress, the more intense the deformation and fractures of a coal body and the stronger the EMR signals. EMR signals reflect the degrees of concentrated stress of a coal body and danger of a rock burst. We selected EMR intensity as the test index of the No.237 gob-surrounded coal face in the Nanshan coal mine. We tested the EMR characteristics of the stress distribution on the strike, on the incline and in the interior of the coal body. The EMR rule of rock bursts, caused by sudden changes in stress, is analyzed. Our research shows that EMR technology can be not only used to test qualitatively the stress distribution of the surrounding rock, but also to predict a possible occurrence of rock burst. Based on this, effective distress measures are used to eliminate or at least weaken the incidence of rock bursts. We hope that safety in coalmines will be enhanced.

Interpreting the Shortwave Infrared &Thermal Infrared Regions of Remote Sensed Electromagnetic Spectrum with Application for Mineral-Deposits Exploration

The ASTER (Advanced Space-borne Thermal Emission and Reflection radiometer) data, including all the 3 parts: VNIR (Visible and Near-Infrared), SWIR (Short Wave Infrared), TIR (Thermal Infrared), were applied for extraction of mineral deposits, such as the Ni-Cu deposit in eastern Tianshan, the gypsum in western Tianshan, and the borax in Tibetan. This paper discusses the extraction methodology using the ASTER remote sensing data and reveals the good extraction results. This paper bravely represents the summary of the main achievement for this field by the scientists in other countries and gives a comparison with the works by others. The new achievements, described in this paper, comprise the extraction of anomalies for Ni-Cu deposit, gypsum, and borax.

随钻中继式电磁波传输技术及应用研究

针对随钻条件下无线电磁波传输技术信号衰减大、传播距离短、信号频率低以及传输速率慢的难题,文章设计了基于准横电磁波(Transverse Electromagnetic Wave,TEM)激励模式的随钻中继式电磁波传输技术。该技术以钻杆作为传输载体,将电磁波在井内的随钻传输模型类比同轴线传输模型,通过使用多组载波频率,在提高传输速率的同时,利用中继接力扩展传输距离。该技术已通过不同地层环境的现场验证,是井下数据传输未来发展的重要方向。

井下表面电磁波协同中继传输方法

在井下进行表面电磁波通信时,中继器布局不合理会导致信号强度减弱,为此,提出了表面电磁波的协同中继传输方法。首先,结合数值模拟与模拟试验结果,分析了表面电磁波的传播特性;然后,利用电场积分方法,建立了井下表面电磁波中继传输系统的数学模型,分析了不同中继器布局和数量对接收机信号强度的影响。研究结果表明,表面电磁波比传统无线电磁波具有更小的衰减和更高的传输速率,可成为一种高效的井下通信方式;应用表面电磁波协同中继传输技术,信号强度可平均提高5.91 dB。研究结果为增大表面电磁波井下通信的传输距离提供了新的技术途径。

双线圈电磁继电器建模与矢量磁场测量分析

双线圈电磁继电器的电磁系统是电能和机械能相互转换的媒介,为实现更理想的能量转换和分布效果,需要模拟和分析磁场能量的分布情况。结合三维建模软件和电磁场有限元分析软件,对双线圈继电器进行仿真研究,测试中测量装置采用柔性协作机器人和三轴高斯计,用相应的模具固定继电器。编写控制机械臂的脚本程序,使其带动高斯计围绕被测继电器按照指定路径运动,实时采集位置信息和磁场信息,实现路径坐标系和绘图坐标系的虚实合一,将机械臂仿真及运行路径的坐标系和上位机空间磁场强度分布绘图坐标系实现坐标一一对应,测量出继电器三维矢量磁场强度。对比仿真得到的磁感应强度数据与测量得到的数据,验证了仿真计算的真实可靠性。

基于FPGA的电磁继电器在线测试系统设计

电磁继电器在现代国防军事、工业自动化以及交通运输等领域应用广泛,当系统中的电磁继电器发生失效时将影响整个电气系统的可靠运行。为了提高电气系统的可靠性,需要检测继电器的特性参数,以评估其工作性能并提高其稳定性。针对电磁继电器触点易失效问题,设计了一套基于FPGA的电磁继电器在线测试系统。采用铁路继电器作为试品,分析继电器的各项特性参数,并选取能反映其触点退化程度的时间参数进行测试。这种能够应用于多型号继电器的便携式在线测试系统,可实时检测继电器吸合和释放过程中的电压变化波形并进行数据存储,为后续继电器的性能状态评估提供了数据支撑,也为电磁继电器的维修维护提供了参考数据。

地铁车辆电磁继电器随机失效分析与寿命预测

电磁继电器是最常用的电气元件之一,大量安装于地铁车辆的各个控制电路中,失效后果严重。触点随机失效是电磁继电器随机失效的最主要原因,对触点随机失效进行分析,确认失效机理。采用韦布尔分布,对电磁继电器剩余使用寿命进行预测,可以在满足安全可靠的前提下,降低维护成本。

控制电缆分布参数对变电站开关场电磁继电器的影响仿真

为了研究控制电缆分布参数对变电站开关场继电器的影响,选取500 kV变电站开关场电磁继电器为研究对象,研究控制电缆末端正接地控制电缆分布参数对其电压的影响。基于控制电缆分布参数、继电器参数等条件,构建电路模型,进行理论和仿真分析。结果表明:继电器为R模型时,其电压波形仅为指数衰减波形;继电器为RL模型时,其电压波形受系数σ、系数k的影响。可见继电器电阻及电感、非故障馈线分布电容均对其电压产生影响。

固体继电器的抗欠压浪涌设计

阐述一种具有较强抗欠压浪涌能力的固体继电器电路的设计。分析普通固体继电器电路输出端接通关断特性存在的缺陷,提出解决方案,仿真分析其有效性,得出输出端接通关断特性图,并对该电路的工作失效率进行分析计算。

电磁继电器故障检测系统设计与实现

文章提出了一种使用C++编程语言开发电磁继电器故障检测系统的方案,该系统包括数据采集、数据挖掘和设备管理模块。采用了三层架构的设计,旨在提高系统的开发效率和可维护性。为了提升故障识别率,引入了K-means算法作为数据挖掘的核心方法。在系统开发中,数据采集模块负责获取与电磁继电器运行状态相关的数据,如电流、电压和温度等。数据挖掘模块使用K-means算法对这些数据进行聚类分析,以识别潜在的故障模式和异常行为。设备管理模块则通过三层架构进行设计,包括数据存储、业务逻辑和用户界面层,以实现对传感器、模型部署等设备的有效管理。

一种电磁式继电器全自动检测装置的结构设计

电磁式继电器是自动化领域常见的电子器件。针对现有电磁式继电器引脚检测装置检测对象单一、检测精度及检测效率不高等问题,结合视觉检测的优势设计一种电磁式继电器全自动封装检测装置,包括支架、检测工位和采集机构等。文章具体说明了利用该装置采集数据的处理方法,进而分析判断继电器引脚是否合格。该装置可在一定程度上提高电磁式继电器引脚检测的精度和效率。