串联阻容分压器频率特性仿真

将电容自身等效串联电阻纳入分压器阻容参数,按集中参数计算方式计算论证了阻容分压器分压原理,通过仿真对比电容分压器与阻容分压器输出频率特性,得出了相同条件下阻容分压器的频率特性优于电容分压器的结论。     

励磁系统阻容保护装置的研究

对阻断式阻容保护和非阻断式阻容保护的参数设计原则进行分析,得出了阻断式阻容保护和非阻断式阻容保护的保护效果的差异,为阻容保护的选择提供了科学依据。     

变阻尼电磁阻尼器的结构设计计算及应用分析

分析了电磁作用力的原理,对基于电磁感应原理可变阻尼电磁阻尼器进行了新型结构及磁路设计,对设计出的这种阻尼器进行了具体参数设定与应用分析.     

基于Fluent的橡胶挤出机流道设计

为满足胎面胶挤出质量的要求并解决传统试差法的缺点,采用经验设计与数值分析相结合的方法,对挤出机流道进行了设计。根据经验及理论改进流道的阻尼结构,运用Fluent分析胶料在流道内的流动状态,证明改进阻尼比简单阻尼分流效果好;设定改进阻尼的三个重要结构参数,分析各参数对流道内胶料的流动状态的影响,并根据影响规律选定最终结构参数;进行挤出实验,分析误差原因并指出后续的研究方向。     

电动助力转向系统阻尼特性分析及测试方法

电动助力转向(Electric Power Steering,EPS)在提供转向助力、减轻驾驶员操纵负担的同时,也能够提高汽车转向性能和驾驶舒适性,进而提高汽车的主动安全性。建立EPS系统仿真验证平台,分析阻尼补偿控制对汽车转向性能影响,结果表明阻尼补偿控制通过设定阻尼补偿控制系数,可改善EPS动态响应及回正性能。提出EPS系统阻尼特性测试方法,准确获得转向系统阻尼系数,为EPS阻尼补偿控制系数的设定提供参数依据。     

分压器宽频特性数字补偿方法的研究

本文提出了利用阻抗法测量双口网络参数,进而计算分压器转移函数的方法。为提高骚扰电压数据的测量精度提出了对分压器的宽频特性进行逐点数字补偿的方法。经分析补偿结果表明该方法可对电压骚扰数据进行补偿。     

基于线性光耦HCNR201的交直流电压传感器的研制

介绍了高线性度模拟光电耦合器HCNR201对模拟电压进行隔离的基本原理和典型应用电路.研制了一种基于HCNR201的交直流电压传感器,能实现对交流、直流或交直流混合的电压信号进行隔离.输入衰减部分采用阻容分压器的结构,保证了传感器的带宽.利用线性光耦在有效工作区域内传输比恒定的特性,通过对其工作电流的特殊设置,实现了双极性模拟电压信号的隔离.给出了测试数据和分析结果.     

未知负载转矩下机械臂关节参数在线辨识及控制参数在线研究

机械臂运行过程中,关节伺服系统的负载转动惯量和阻尼系数呈现时变特性,现有方法在未知负载转矩的情况下无法完成转动惯量和阻尼系数同时辨识。提出一种基于离散模型参考自适应算法在线同时辨识负载转动惯量和阻尼系数的方法,通过对关节伺服系统电机的机械方程离散化得到含有转动惯量和阻尼系数的模型自适应参考模型,采用朗道离散时间递推参数辨识机制推导模型自适应率进行参数辨识;利用参数辨识结果和设定的误差阈值在线优化控制参数。此方法能在线同时辨识转动惯量和阻尼系数并根据辨识结果优化速度环PI控制器参数值,提高速度的动态响应性能。仿真结果证明了参数辨识方法和控制器参数在线优化方法的有效性。     

基于Bouc-Wen模型的阻尼负载模拟器研制

研制了一种数字控制阻尼负载模拟器,可以模拟Bouc-Wen等非线性滞回模型,通过设定参数来模拟不同的负载特性.如果应用在地震模拟振动台实验中,通过改变负载模拟器参数就可以模拟成不同类型的阻尼器,一方面可以研究阻尼器对结构的减振效果,另一方面可以研究不同类型结构所需要的最优阻尼器参数.该阻尼负载模拟器可以广泛应用于实验领域来代替阻尼器,是一种主动调节型的阻尼器.     

轴向柱塞泵流量脉动的研究

对轴向柱塞泵流量脉动进行了分析研究,通过对流量方程进行傅里叶变换,求得流量方程的另一种表达式,即泵的流量可以分成常量部分以及脉动部分,同时对脉动部分的各次谐波幅值进行了研究和讨论,得出了在系统中加阻尼后,能起到阻容滤波的作用,在一定程度上减小了压力脉动的幅值.     

An inductive voltage divider positioned near the liner

An inductive divider for measuring voltages near a radiating load, which is a hollow cylindrical assembly compressed by a 3-MA current pulse, is described. Some results that were obtained in experiments on the Angara-5-1 facility using this divider are presented. The nanosecond resolution of the sensor and closeness of its position to the load allow observation of the moment of breakdown of wires using the obtained voltage signals. Analysis of voltage and current signals allows evaluation of the energy deposition to the wires before the breakdown and the parameters of plasma that is generated around them.     

百吨级汽车起重机分动器的开发

介绍了国外起重机分动器的产品情况,并结合汽车起重机的整车特点分析了汽车起重机分动器的设计技术难点,从分动器的主要技术参数确定、整体方案设计和高强度齿轮传动、强制润滑和散热系统、全时驱动差速器、前输出结构及壳体设等方面介绍了百吨级汽车起重机分动器的设计,通过对分动器进行台架和装车试用,验证了分动器总成的开发效果。     

A controllable voltage divider for Hamamatsu R11410-20 photomultipliers for use in the RED 100 emission detector

A control circuit for the operation of Hamamatsu R11410-20 photomultiplier tubes (PMTs), which is intended for use in the RED 100 liquid-xenon emission detector, was developed. To prevent the photocathode degradation due to intense flashes that are associated with signals from high-energy cosmic-ray muons, the circuit forms a voltage pulse that is fed to the PMT photocathode and “blocks” the interelectrode gap between the photocathode and the first dynode. Thus, electron current through this gap is stopped for some time, which suffices for the complete collection of ionization electrons in the RED 100 detector after a cosmic muon passes its sensitive volume. The parameters of the circuit are selected such that the PMT relaxation time after the termination of a blocking pulse, which is determined by the transient processes in the divider, is ～200 μs for a divider with a total resistance of 20 MΩ. This is acceptable for the intended application of the RED 100 detector in an experiment on the search for coherent neutrino scattering off xenon nuclei.     

基于复合左／右手传输线的双频功分器

本文介绍了一种新型的基于复合左／右手（CRLH）传输线理论的双频功分器设计方法,该功分器工作于900MHz和1800MHz。用集总电感和电容元件构成的复合左／右手传输线在900MHz和1800MHz的相移分别是超前和滞后90°。完全可以替代传统功分器中的四分之一波长阻抗变换传输线,且具有占用面积小和可设计工作于任意两个频率的优点。在双频工作的现代无线通信系统中有很广阔的应用前景。     

Statistical analysis of the characteristics of some basic mass-produced passive electrical circuits used in measurements

Statistical properties of some basic mass-produced passive electrical circuits used in measurements are analyzed in this paper, using methods for expressing measurement uncertainty of indirectly measured quantities. The focus of this paper is on electrical circuits whose defining parameters are obtained as non-linear functions of component parameters. Variants of voltage divider and Wheatstone bridge circuits significant for measurement practice are investigated in detail. Even if distributions with symmetrical probability density functions (PDFs), such as uniform or normal, are adopted for the parameters of the components comprising a circuit, non-linearity of the circuit function gives rise to asymmetry in the PDF of the circuit’s parameter. The asymmetry of the PDF causes the mean and the nominal value of the circuit parameter to differ.     

A differential high-voltage divider

The design, main design formulas, and test results of a small-size differential high-voltage divider are presented. The conditions determining correctness of using the divider for measuring nanosecond high-voltage signals are obtained. It is shown that the differential voltage divider has some limitations in low- and high-frequency regions. Experiments have been performed on a TэY-500 pulsed electron accelerator with the following characteristics: the accelerating voltage is 350–450 kV, the base pulse duration is 100 ns, the rise time is <5 ns, and the complete pulse electron energy is up to 250 J. The pulse repetition rate is 1–3 pulses/s. To restore the shape of the measured voltage, it is necessary that the output signal from the voltage divider be integrated. The measurement error does not exceed ±10%.     

Tunable quasioptical power dividers operating in the millimeter wavelength range

Circuits and principle of operation of quasioptical power dividers based on two-row periodic structures, formed by grids of metal bars and a dielectric waveguide placed along their longitudinal axis, are described. The experimental studies of power divider prototypes in a frequency range of 60–80 GHz have shown a possibility of regulating the emitted power level in the main divider arm by changing longitudinal and angular coordinates of the two-row periodic structure, which can be used for designing quasioptical attenuators.     

全球卫星导航系统接收机的正交二分频器设计

将全球卫星导航系统(GNSS)接收机用于手持移动设备必须降低正交二分频器等大功耗模块的功耗,因此,本文提出了工作于1V电压以下的正交二分频器.使用提出的正交二分频器可使电路在各工艺角下高速稳定的工作,并大大降低模块的功耗.首先,介绍已有的高速二分频器.接着,计算了所提出结构的直流静态偏置,并对提岀的锁存器进行小信号建模和分析.最后,根据小信号模型分析得到的条件和GNSS接收机的应用要求,设计了提出的低功耗结构.实验结果表明:提出的二分频器最高工作频率为6.55 GHz,最低可工作到0.25 GHz,消耗电流为0.8mA,占用面积为0.014 4 mm2.提出的电路结构在0.13 μm CMOS工艺上实现,可稳定工作于1V电压下,目前已成功应用于低功耗的移动GNSS接收机中.     

A small-power transistor divider for photomultiplier tubes

A high-voltage transistor voltage divider for photomultiplier tubes consists of a high-resistance linear resistive divider specifying potential distributions between dynodes and emitter followers maintaining this distribution. The divider features a low dissipation power and stable gain of the photomultiplier tube, when the average anode current varies in the entire measurement range.     

高精度高压电压表

本文介绍的高精度高压电压表,是以标准电压通过电容系统比较分压电阻的电压降,避免分压电阻表面漏电流对测量精度的影响。电压测量的相对误差<10~(-4)。