用PLC实现电气主接线模拟操作过程

为提高供电的可靠性,用可编程序控制器(简称PLC)代替继电器实现电气主接线--双母线切换母线时隔离开关和断路器的操作过程.设计模拟电路和PLC控制程序,以实现母线切换,误操作判断,并用灯光来反应断路器的状态,用音响作为故障报警信号.     

基于PMSM的电动负载模拟器建模与控制

电动负载模拟器是舵机测试和半实物仿真的关键设备之一.介绍了永磁力矩电机驱动的电动负载模拟器的结构和工作原理,建立了其数学模型,并对控制系统进行了设计和仿真分析.针对加载梯度大范围变化条件下,一套固定的PID参数适应性较差的问题,设计了基于CMAC的复合控制方案,控制系统表现了较强的自适应性.     

基于Internet技术的远程实验模拟系统

网络技术的进步,促进了远程教育与网络教育的发展,而基于Internet技术构造远程实验模拟系统可以提高网上实践教学的能力,从而形成一个更为完善的网上教学体系,论述了开发环境的建立和系统功能的技术。     

家居装修中电路设计及施工应注意的几个问题

在家居装修时应根据当前生活水平和发展的需要,进行电路设计,并应考虑好保护接零和接地,音响的预埋线问题,注意纠正施工中出现的问题。     

音响胜地录

暴君的“耳朵” 意大利西西里岛有个叫“狄阿尼西亚士的耳朵”的山洞,从洞顶到洞底深40m,人在洞顶贴耳俯壁细听,可听到洞底人的呼吸声。据说,古代一个名叫狄阿尼西亚士的暴君,手段残忍,用该山洞监禁政治犯。狱卒的耳朵时刻监听着犯人的一举一动,许多义士因为一句话而获罪。     

电力推进 模拟系统 实时仿真 时延分析 MATLAB

分析了电力推进负载模拟系统的原理,采用MATLAB实时仿真工具RTW和多功能数据采集卡PCI-1711实现负载模型到模拟变流器的控制.基于MATLAB/Simulink对模拟系统的时延影响进行了仿真,分析了负载模型时延对模拟电机转矩控制的准确性和稳定性的影响.通过建立模拟电机转矩控制的闭环传递函数和频域的Bode图,进一步分析了时延影响,采用修正闭环增益的方法对时延进行了补偿,达到与理想时延下近似的控制效果,并得以仿真验证.     

虚拟现实的特点与应用

我们经常从媒体中看到某军事演习采用计算机推演,这些技术是怎么实现的昵？它就是虚拟现实技术,就是人们利用计算机生成一个逼真的三维虚拟环境,通过自然技能使用传感设备与之相互作用的新技术。作为一项尖端科技,虚拟现实集成了计算机图形技术、计算机仿真技术、人工智能、传感技术、显示技术、网络并行处理等技术的最新发展成果,是一种由计算机生成的高技术模拟系统。它最早源于美国军方的作战模拟系统,20世纪90年代初逐渐为各界所关注并且在商业领域得到了进一步的发展。     

DEM/CFD modelling of the deposition of dilute granular systems in a vertical container

Deposition of granular materials into a container is a general industrial packing process. In this study, the deposition behaviour of dilute granular mixtures consisting of two types of particles that were of the same particle size but different particle densities in the presence of air was numerically analyzed using a coupled discrete element method （DEM） and computational fluid dynamics （CFD）. Bilayer granular mixtures with light particles at bottom and heavy particles at top were first simulated. It was found that the presence of air significantly affected the flow behaviour of the bilayer mixtures. For the system with a relatively low initial void fraction, the air entrapped inside the container escaped through the dilated zones induced due to the friction between the powder bed and wall surfaces. The escaping air streams entrained light particles that were originally located at the bottom of the granular system. Consequently, these light particles were migrated to the top of the granular bed at the end of deposition process. More light particles were migrated when the deposition distance was increased. For the system with a high initial void fraction, some light particles penetrated into the top layer of heavy particles and created a mixing zone. Deposition of random mixtures with different initial void fractions was also investigated and the influence of initial void fraction on the segregation behaviour was explored as well. It was found that the increase of void fraction promoted segregation during the deposition in air. It was demonstrated that, for granular mixtures consisting of particles of different air sensitivities, the presence of air had a significant impact on the mixing and segregation behaviour during the deposition.     

All-optical 2R regeneration based on self-induced polarization rotation in a single semiconductor optical amplifier

An all-optical 2R regeneration based on self-induced polarization rotation in a single semiconductor optical amplifier is presented. A theoretical model is built up to simulate the system performance. Experiment evidence is also provided. An extinction ratio improvement of 8.3 dB is obtained at a bit-rate of 10 Gbit/s. In the BER measurements, 6 dB improvement of the power penalty is achieved, clearly demonstrating the feasibility of the proposed scheme. Our approach has a simple structure, and allows photonic integration.     

数字网络的一种离散等效设计方法

给出数字网络的一种等效设计方法。首先应用小步合成方法将模拟网络离散化 ,得到状态空间中的离散递推公式。通过z变换 ,得到数字网络的离散传递函数。已将提出的设计方法编制成软件DIGNET ,该软件根据模拟网络的传递函数直接给出要求的数字网络 ,并可对数字网络进行仿真和频域分析。