一拖三循环变频在供水站的应用

本文主要介绍了JX-P系列变频器一拖三循环变频原理及实现,浅析了一拖三循环变频实现的具体过程。     

Efficient Nakagami-m fading channel Simulation

An efficient method for generating correlated Nakagami-m fading envelope samples is presented; this method is applicable for arbitrary values of the fading parameter m. The new method is compared to other methods used to generate Nakagami-m random variates. An accurate approximation to the inverse Nakagami-m cumulative distribution function, valid for all values of m, is derived. Uncertainties regarding the autocorrelation of the Nakagami-m fading process are discussed. The fading envelope autocorrelation is determined by simulation and asymptotic analysis.     

“电力拖动自动控制系统”中的仿真教学

＂电力拖动自动控制系统＂课程涉及到各种电动机控制系统的模型建立、系统分析和系统设计等的基础理论。其特点是概念抽象、实验难度大及实验成本高,这就要求该课程在教学内容及教学方式上都要有别于其它课程。我们以计算机辅助教学为手段,通过对具体仿真教学案例的设计,利用Matlab/Simulink软件搭建仿真程序应用于该课程教学中,使学生能直观地领会和理解课程的分析方法和实时处理结果。     

脉冲变压器MOSFET栅极驱动电路分析与仿真

为了使BUCK变换器中MOSFET能够浮地工作,采用脉冲变压器构成其栅极驱动电路.分析驱动电路的结构和工作原理,对脉冲变压器进行设计,并给出增大磁化电感和减小漏感的方法,从而有效传输驱动波形,有利于降低MOSFET的损耗,提高BUCK变换器的效率.通过软件和实验对脉冲变压器驱动电路进行电路仿真和实验验证.     

飞机升压式空气制冷循环系统仿真研究

针对飞机环境控制系统中的升压式空气制冷循环,在EASY5平台上进行了稳态和动态仿真研究.首先以某型飞机环境控制系统的升压式空气制冷循环为例,详细描述了系统的结构和工作原理,以及系统中各主要组件如压缩机、涡轮、换热器、阀门及PI控制器的数学模型及其在EASY5气体动力学应用库中的使用方法.然后利用软件自带模块组件搭建飞机升压式空气制冷循环的仿真系统,对系统使用牛顿迭代法进行稳态求解,使用BCS-Gear变步长积分法进行动态分析.应用结果表明.该系统精度较高,具有一定的实用性和推广价值,为EASY5在飞机环境控制领域的应用及国内飞机环境控制系统仿真的研究提供参考.     

An Efficient Simulation Environment and Simulation Techniques for Bluetooth Device Design

Validation of an System-on-Chip (SoC) design with networking capability needs global simulation of the whole system including the network as well as the SoC design itself. Especially, it is needed to validate the interoperability of SoCs from different vendors. In this paper, we propose a simulation environment and simulation techniques for efficient validation of such SoC designs and apply them to networked Bluetooth SoC designs. The environment enables two types of simulation. One is modular enough to include the simulation of other vendors' Bluetooth devices and the other is optimized to achieve fast simulation in developing in-house Bluetooth devices. Especially, the former is scalable in that it keeps the constant simulation runtime despite the increase of the number of Bluetooth devices. Since multiple simulators are involved, the global simulation is still slow. Thus, the simulation efforts need to be minimized to shorten the design cycle. We present two simulation techniques, a concept called grouped message for reduction in simulation runtime and a system debug scenario called fix–modify–restart for reduction in the number of simulation runs. The former is to reduce inter-process communication overhead between simulators in the global simulation. The latter is to reduce repeated simulation runs in the conventional design cycle. Experimental results show the scalability of the presented simulation environment, reduction in simulation efforts by two simulation techniques.     

基于MATLAB5.2的电力传动控制系统仿真

以电流环型ＰＷＭ变频器控制三相异步电动机的仿真为例,详细介绍了ＭＡＴＬＡＢ５．２中的电力系统工具箱在电气传动控制系统仿真中的应用。     

Graphene Implanted Shape Memory Polymers with Dielectric Gene Dominated Highly Efficient Microwave Drive

Microwave-driven strategy shows many advantages including selective energization, uniform heating, and high penetration depth, which is a hot topic in wireless actuators. Understanding microwave stimulus-response mechanisms is the key to developing universal construction strategies for advanced microwave-driven actuators. Herein, reduced graphene oxide (rGO) with specified dielectric genes and thermal properties is implanted into the shape memory polymer, liquid crystal elastomer (LCE) as an example, to construct soft, reversible, and sensitive microwave actuators. Based on the analysis of microstructure and dielectric properties, LCE-rGO composites exhibit excellent polarization relaxation-dominated dielectric loss and electromagnetic (EM) energy conversion ability. The maximum dielectric loss factor (ε″) and loss tangent (tan δ_e) of LCE-rGO are dramatically increased by 216% and 87.5% compared to pure LCE, respectively, and the optimum apparent energy harvest efficiency is 19.4 times higher than that of LCE. In addition, the implantation of rGO significantly lowers the microwave actuation threshold of LCE-rGO composites and reinforces their stimulus-response capacity. Response time under 750 W microwave irradiation of LCE-rGO is shortened to <10s. These findings can provide a solid basis for the design and fabrication of highly efficient microwave stimuli-responsive polymers and enlighten a new approach to wireless actuated smart devices.     

重庆轨道AFC驱动主板模拟测试平台搭建

AFC(Automatic Fare Collection)系统是实现轨道交通售票、检票、收费、统计、清分、管理等全过程的自动化系统.半自动售票机(BOM)和自动售票机(TVM)在AFC系统中有着举足轻重的地位,而票卡传输控制驱动主板是它们中最重要的主板之一,也是故障率最高的主板.本文针对半自动售票机(BOM)和自动售票机(TVM)票卡传输控制驱动主板容易损坏,维修点无设备测试修好的主板的现状,综合运用了串口抓包、协议分析、单片机模拟发包等技术成功实现了对其测试平台的模拟.实践证明,模拟测试平台效果显著,非常具有借鉴意义.     

基于FPGA的电力传动实时仿真平台的设计

针对传统电力传动仿真软件如MATLAB/SIMULINK具有仿真时间长、对计算机硬件要求高等缺点,给出了一种针对电力电子装置实时仿真系统的建立方法,通过对带阻感负载的H桥逆变器进行特性模拟,给出了基于System Generator的实现流程。在FPGA内部实现一个SPWM信号发生器、H桥仿真器及阻感负载仿真器,构成一个完整的单相H桥逆变系统。最后在Xilinx公司S3EStarter_ug230 FPGA实验平台上对整个系统进行实时仿真,并采用DAC对仿真波形进行输出显示,结果验证了整个实时仿真系统的正确性。     

PIC单片机在汽车工况模拟系统中的应用

基于PIC单片机 ,设计了混合动力电动汽车的工况模拟系统。文章说明了系统的结构与工作原理 ,着重阐述了工况模拟器的软硬件实现 ,并给出了控制电路原理图及软件设计要点。     

循环模拟控制4步设计方法

在各厂家的PLC(可编程逻辑控制器)实验设备上都有各种循环控制实验,但用PLC程序实现的方法有不同的版本,程序的设计没有规律,不便于掌握设计思路,文中介绍采用4步法实现PLC各种循环模拟控制,只要按步骤进行设计,关键是掌握时间控制电路的设计和循环次数的选择,重点是用好左移位指令,就能抓住循环模拟控制设计要点,并能方便地设计出所要求的控制程序,达到满意的循环控制要求。该方法具有通用性,对PLC的教学、实验、课程设计具有很好的借鉴作用。     

一种高效实时的烟雾动画模拟方法

近年来,基于物理模型的烟雾模拟成为计算机动画领域中的一个研究热点。早期的基于物理的方法很难同时满足实时性和真实感的要求。文章采用流体力学无粘不可压欧拉方程组作为基本物理模型,添加漩涡约束力来描述流体中的漩涡,简化了数值模拟计算的同时保证了模拟的真实感。数值计算上,采用半拉格朗日方法、高斯一塞德尔迭代法等稳定的求解方法来实现大时间步长模拟,保证了模拟的实时性。实验表明,该方法是一种高效实时的烟雾动画模拟方法,而且模拟结果真实感较强。     

An Efficient Method of Simulation for Time-Sharing Systems

Simulation of requests for service from a large number of low duty cycle independent users is apt to cause a severe computational load. A method is presented for the software implementation of an efficient simulator. It can be applied to the investigation of many time-sharing systems, such as satellite demand assignment (DA), computer time sharing, and traffic routing. More generally, the method generates independent multivariate Poisson distributions when the number of variables is very large and the value of the parameter in each distribution is very small.     

光控伺服系统建立、建模与仿真

介绍了一种具有抗电磁干扰,信息传输快的光控伺服系统的组成,并详细阐述了此系统关键组成部分——光伺服阀中光驱动器所应用的光致伸缩陶瓷材料(PLZT)的应用原理以及其在阀中具体的实用结构。对光控伺服系统的各个环节进行系统级的建模与仿真分析,讨论其抗电磁干扰能力,比较不同控制方式PLZT光执行机构精度的影响。探讨了光控伺服系统,尤其是光伺服阀光驱动器的实用性以及其有待解决的问题。     

电力拖动类课程的仿真实验教学改革

电力拖动类课程传统实验具有实验过程抽象,实验难度大及实验成本高等不足之处。我们将计算机虚拟仿真技术引入到电力拖动类课程的教学过程中,并综合应用Visual C++,Matlab/Simulink,MS Access和MS Word构建了电力拖动类课程虚拟仿真实验系统。实践证明虚拟仿真实验系统可以解决传统实验存在的不足,调动了学生学习的积极性,在学生科学素养和能力培养方面也起到了积极作用。     

飞机供电系统集成仿真软件电驱动设备的仿真模型研究

随着现代飞机电气化程度不断提高,供电系统的用电设备不断增加,电能品质成为飞机电网的重要问题。集成仿真能够对电气设备高度集成化的供电系统动态性能进行分析,是解决电能质量问题的有效方法。在集成仿真软件的研究中,建立各种用电设备的仿真模型是关键。本文研究了其中典型的用电设备-电动机构成的电驱动装置的仿真建模,其目标是在能够准确表明用电性能的基础上缩短仿真运算时间,讨论了不同设备的建模方法,并对仿真结果做了分析。     

直流伺服驱动系统的参数仿真优化与设计

针对控制系统中瞬态性能要求较高,单环控制系统无法满足要求时,实行多环控制,并按照有内环到外环的方法依次进行参数优化.本文以直流电机双闭环调速系统为例,运用仿真优化方法来设计两个PI调节器的参数,使该系统的稳态指标和动态指标均达到设计的要求.