高速电磁阀电磁铁的研究与开发

针对高速电磁阀快速响应的关键因素电磁铁电磁力大小与线圈驱动两方面的问题。对电磁铁铁芯形状、工作气隙相对于线圈位置、工作气隙大小、安匝数、圆形铁芯面积等因素影响电磁力进行了分析研究;提出了3种驱动电路,对3种线圈驱动电路影响电磁铁响应特性进行了对比,并运用Ansoft Maxwell软件对各因素与电磁力大小的关系、3种线圈驱动电路与电磁铁响应特性进行了模拟仿真计算,最后对电磁铁的开发提出了一种优化方案。研究结果表明,该优化方案对高速电磁阀的快速响应有一定的提升。     

Computer-controlled testing system for investigating the dynamic characteristics of contactors with A.C. electromagnet drives

An original computer-controlled measurement system with electrodynamic sensor is presented in this paper. The system was used to examine simultaneously dependencies of time related electromagnet coil current, electromagnet coil voltage, electric power supplied to electromagnet coil, voltage across contacts, acceleration, speed, path and kinetic energy of contactor moving element. An additional software allows diagrams of the following parameters to be obtained: maximum and minimum acceleration, maximum speed and kinetic energy of contactor moving element, electric energy supplied to electromagnet coil and times typical of alternating current electromagnetic drive for selected values of the coil supply voltages and various switching on angles of this voltage (within the range 0–170°). Results of the investigation enable also to take a view on such parameters of the designed equipment as, for example, making time or rebounds of the contactor contacts. The system is very useful to verify the results of investigation of computer simulated contactor closing.     

Dynamic performance of high speed solenoid valve with parallel coils

The methods of improving the dynamic performance of high speed on/off solenoid valve include increasing the magnetic force of armature and the slew rate of coil current, decreasing the mass and stroke of moving parts. The increase of magnetic force usually leads to the decrease of current slew rate, which could increase the delay time of the dynamic response of solenoid valve. Using a high voltage to drive coil can solve this contradiction, but a high driving voltage can also lead to more cost and a decrease of safety and reliability. In this paper, a new scheme of parallel coils is investigated, in which the single coil of solenoid is replaced by parallel coils with same ampere turns. Based on the mathematic model of high speed solenoid valve, the theoretical formula for the delay time of solenoid valve is deduced. Both the theoretical analysis and the dynamic simulation show that the effect of dividing a single coil into N parallel sub-coils is close to that of driving the single coil with N times of the original driving voltage as far as the delay time of solenoid valve is concerned. A specific test bench is designed to measure the dynamic performance of high speed on/off solenoid valve. The experimental results also prove that both the delay time and switching time of the solenoid valves can be decreased greatly by adopting the parallel coil scheme. This research presents a simple and practical method to improve the dynamic performance of high speed on/off solenoid valve.     

基于线圈瞬态电流参数优化的真空断路器永磁操动机构动作特性研究

针对永磁操动机构出力不足、动作特性与真空断路器开断性能难以配合的问题,对单线圈双稳态真空断路器永磁操动机构进行了研究,在剖分永磁操动机构结构的基础上,分析了磁路磁链的分布关系,建立了三维电磁场数学模型。采用有限元法仿真分析方法,求解了永磁操动机构线圈瞬态电流与动铁芯合闸动作特性之间的关系,并探讨永磁操动机构储能电容容量、电源电压、线圈匝数和负载等效质量等主要参数对真空断路器合闸动作特性的影响。研究结果表明,仿真计算数据与试验测试数据吻合,优化后的电容、线圈及负载参数可对永磁操动机构的位移检测、系统故障诊断、结构改进等提供理论依据。     

永磁伺服电机嵌入式位置检测理论及误差分析

针对现有的永磁伺服电机位置传感器存在成本高、体积大的缺点和新兴的无传感器技术计算复杂及依赖电机参数的不可靠性问题,提出了绕制时栅线圈检测电机转动位置的方法,但由于绕制时栅线圈检测的方法存在获取信号复杂、测量稳定性差以及线圈绕制不均匀增加误差的缺点,在此基础上,提出了一种基于隧道磁阻效应(TMR)和时栅技术的永磁伺服电机嵌入式位置检测新方法。在原理分析的基础上,根据行波表达式的理论推导,分析了单路和双路驻波幅值不相等所导致的误差规律,为检测结构的优化和进一步提高测量精度奠定基础。最后通过实验,验证了嵌入式位置检测理论分析的正确性以及检测方案的优越性,所提出方法的检测精度较绕制时栅线圈的检测方法提高了3倍,稳定性提高了5倍。     

自检测磁悬浮轴承系统的研究

基于差动变压器原理 ,提出从控制电磁铁线圈的两端提取因偏置磁通随位移变化而互感的诱导电压 (电流 ) ,作为反馈信号构成闭环控制的自检测磁悬浮轴承系统。偏置电磁铁采用脉宽调制 (PWM )电压信号驱动。所要检测的互感电压 (电流 )信号的PWM的电流频率的成分是电磁铁互感系数的函数 ,互感系数又是转子气隙位移的函数。该信号经过全波整流得到与转子位移成比例的电压信号 ,将该位移信号由PID控制器转换为调整转子位移的控制信号     

A study on the design and application of optimized solenoid for diesel unit injector

With the Environmental Protection Agency (EPA) regulating the amount of NOx, Particulate, HC and CO at all driving conditions, emission standards for diesel engines are becoming more stringent than ever. To meet future emission regulations, researchers have proposed two solutions based on injection control, the common-rail type injection system, and the unit injection system. Most researchers agree that the electronically controlled unit injector, which realizes high injection pressure and precise control of SOI (Start Of Injection) and injection quantity, has an advantage in meeting future emission regulations. In order to control the start and end of injection, each unit injector contains a time-controlled high speed solenoid valve. Thus, the fuel injection quantity is determined by the time interval between closing and opening of the solenoid valve. This study introduces a method for the design of the solenoid which is installed in the unit injector. It is shown that there are certain significant parameters to be optimized to improve solenoid performance: inductance, stroke, input voltage, coil resistance, load and switching time.     

互感式自检测磁悬浮轴承系统的检测原理研究

基于差动变压器原理，提出从控制电磁铁线圈的两端提取因偏置磁通随位移变化而互感的诱导电压（电流），作为反馈信号构成闭环控制的自检测磁悬浮轴承系统。偏置电磁铁采用脉宽调制（PWM）电压信号驱动。所要检测的互感电压（电流）信号的PWM的电流频率的成分是电磁铁互感系数的函数，互感系数又是转子气隙位移的函数。该信号经过全波整流得到与转子位移成比例的电压信号，将该位移信号由PID控制器转换为调整转子位移的控制信号。     

基于ANSYS的电子提花机电磁阀性能研究

通过建立基于ANSYS电磁阀组件的电磁分析模型,得到其磁力线、磁通密度、电磁强度、电磁力,分析稳态状态下电磁力与电压的二次关系,并通过MATLAB建立F/U的拟合关系式,从而对驱动电压进行优化设计,并可对电磁阀组件的结构参数如电磁铁形状、线圈匝数、吸合面积、磁性材料、复位弹簧参数等进行优化设计。     

基于电流调制的电磁开关阀开关特性研究

电磁开关阀是阀控液压系统中重要的基础流控原件，其开关特性决定系统整体性能。传统驱动方式下，阀芯位移响应滞后于励磁驱动电流，阻碍频响的提高。提出通过建立位移反馈提升阀芯在阶跃励磁电流作用下的电磁力的响应特性，进而提升电磁阀位移频响的方法。对二位二通电磁开关阀建立了动力学与电磁学方程，搭建了阀芯电磁-动力学关键参数测量装置。试验验证了试验装置可行性并获得了阀芯位移响应的开环传递函数。结合试验数据，在Simulink中搭建了反馈对电磁开关阀开关特性影响的验证系统。仿真结果表明，通过利用电磁阀位移反馈，阀芯位移对励磁线圈的阶跃响应改善显著，响应时间相比开环阀芯驱动缩短了近53%。     

基于ARM7的喷气织机电磁阀控制电路

为完成喷气织机高频电磁阀的实时控制,提升对电磁阀工作时的故障检测能力,设计了基于ARM7的电磁阀高速驱动和电流检测反馈控制系统。以ARM7处理器的芯片LPC2478为微控制器,并在数据、地址总线基础上,通过采用复杂可编程逻辑器件(CPLD)扩展了输出口线;针对喷气织机电磁阀高频特性,设计了高、低压复合的驱动控制电路;为判断电磁阀工作性能的优劣,增加了电流检测环节。试验结果表明,该系统运行稳定、高效,通过对电流检测反馈数据的分析,提高了喷气织机生产的质量和效率。     

铁磁性构件缺陷的脉冲涡流检测模式研究

针对铁磁性材料的脉冲涡流检测信号比较复杂的问题,建立脉冲涡流矩形传感器检测模型,提出了矩形探头中同时存在脉冲涡流与脉冲漏磁检测区域,并进行脉冲电磁检测的仿真分析,研究了缺陷和矩形探头轴线所呈角度的最佳检测位置。仿真和实验结果表明了矩形探头的脉冲涡流有效检测区域为探头正下方的边框区域,而脉冲漏磁有效检测区域为矩形线圈中心的正下方区域。脉冲涡流最佳检测点为矩形探头轴线与缺陷呈10°附近位置,而脉冲漏磁最佳检测点为矩形探头轴线与缺陷呈70°位置。     

基于Ansoft的比例电磁铁建模与仿真

针对比例电磁铁结构参数难以获得问题,提出基于其组成结构及设计原理、依据样本输出特性反求电磁铁结构参数的方法,据此利用Ansoft软件建立比例电磁铁有限元模型.不同输入电流下仿真所得行程-力特性曲线表明,其趋势与理论分析相一致、数值上与样本特性参数相吻合,说明所建比例电磁铁模型能正确反映其工作特性,可借助联合仿真将其作为比例电磁阀AMESim模型中的信号转换单元,从而为含有比例电磁阀液压系统的AMESim仿真提供基础保障.     

水液压数字阀的电磁场数值研究

介绍了一种由2个二位三通换向球阀集成于一体的数字开关阀。该阀的阀体部分可作为电磁铁轭铁,衔铁部分可作为放大杠杆,从而使阀体和杠杆成为磁路的一部分。电磁线圈密封于阀体内,有良好的耐压性。因此,该阀适用于在海洋环境水下作业的液压系统。文中重点研究了位于电磁铁铁芯头部与衔铁接触处,能够咬合的特殊锯齿结构。在不同结构和几何尺寸下,利用有限元分析软件ANSYS对于电磁铁铁芯和衔铁部分进行了电磁场数值分析,得出电磁吸力特性曲线。仿真结果表明,这种具有特殊锯齿结构的电磁铁,在咬合前期具有较大的吸合力,咬合后期吸合力逐渐减小,因此能减小撞击且具有较高的响应频率。     

线性测微电感的精化

为提高测微电感传感器的测量精度,提出了基于赫姆霍兹线圈理论设计螺线管线圈的方法,改善了螺线管线圈内轴向上磁场的分布均匀性。首先,分析了螺线管线圈模型,建立了螺线管线圈参数与轴向磁场强度分布相互关系的广义函数模型。然后,通过线圈与磁芯的尺寸确定了系统轴向磁场强度分布函数模型,结合磁芯移动区间范围设置磁场均匀度最小误差目标函数,通过对目标函数寻优得到各螺线管线圈的各项参数。最后,搭建了测微电感传感器的测试系统,测试了传感器性能。实验结果表明:与传统线圈相比,改进型螺线管线圈在100μm测量范围内的线性度由0.46%提高到0.30%。实验显示通过对不同规格的螺线管线圈进行组合,可使得螺线管内轴向上磁场强度分布均匀,从而提高了测量精度。     

非接触式电能传输系统的松耦合变压器特性分析

分析了松耦合变压器的特点,利用有限元模型分析了铁芯材料、线圈位置、气隙大小对变压器耦合系数的影响,并通过实验验证了模型的正确性.同时针对原/副边漏感的特性进一步讨论了原/副补偿问题,并给出了具体的补偿网络.     

电力变压器绕组变形检测技术研究

目前常用于电力变压器内部绕组变形检测方法是将内部绕组的频率响应曲线与参考响应特征曲线进行对比。本文针对参考特征曲线的缺失将影响频率响应技术的可行性的问题,提出一种对相同绕组不同连接方式的频率响应曲线差异进行分析实现对电力变压器内部绕组变形检测的技术。通过模拟实验和仿真验证表明,通过不同连接方式的绕组频率响应曲线之间的差异能够有效显示检测高压绕组和低压绕组之间轴向位移和低压绕组径向变形。     

大型矿井变频调速提升同步电动机的设计应用

概括了矿井提升同步电动机的电磁、结构等方面的设计要点。在电机电磁设计方面,说明了对于变频电源特点,如何选择电机容量、额定电压,确定极对数、定子铁心外径及气隙磁密、定子线圈每相串联匝数和定子铁心长度等初步设计需要考虑的问题。进而对详细计算进行说明。在结构设计方面,分别对定转子的组成和定转子线圈结构特点进行了介绍。     

一种新型采样点控制方法的提出及电路设计和仿真

介绍了利用辅助线圈实现反馈的反激式开关电源的控制原理,以及采样点控制电路在其中的作用,在此基础上提出了一种新颖的单端输入采样点控制电路。其优点是：电路总是动态的修正每个周期的采样时间点,使之与脉冲宽度的相对位置保持不变,这样可以大大减小控制偏差,从而获得高的控制精度。     

Switching frequency response characteristics of a low cost wireless power driving and controlling system for electrically tunable liquid crystal microlenses

The essential switching frequency response characteristics of a low cost wireless power driving and controlling system for electrically tunable liquid crystal microlenses (ETLCMs) are obtained. The wireless power system is mainly composed of two coils with different radius and winding as well as a power metal-oxide-semiconductor field effect transistor switch. The voltage response in the small coil, which is connected directly with ETLCMs, is measured and analyzed under the condition of changing some key parameters of the coil system, such as the width of switching frequency region and the duty-cycle of the switching signal ranging from 20% to 80% in intervals of 20%. Through extending the switching frequency range to a few hundreds of kilohertz, an attractive property of only modulating switching frequency to tune precisely the rms voltage in the small coil for ETLCMs is presented. Some interesting phenomena in high frequency regions, for instance, the rms voltage being stable or slightly changed as the frequency, the voltage response cutoff or disappearance after the frequency surpassing a threshold value, and then regeneration after lowering the frequency to lower frequency point than that of generating voltage response cutoff during increasing frequency, are also discovered.