Analysis and design of DSP-based dual-loop controlled UPS inverters

This paper presents a novel digital dual-loop control scheme of the PWM (Pulse with modulate) inverter. Deadbeat control technique are employed to enhance the performance. Half switching period delayed sampling and control timing strategy is used to improve the system dynamic response. Simulation and experimental results presented in the paper verified the validity of the proposed control scheme.     

带滑移铰空间机械臂的动力学与协调运动的滑模控制方法

讨论了载体位置不受控制的带滑移铰两杆空间机械臂本体与末端抓手协调运动的控制问题。结合系统动量守恒系统我们导出了系统的动力学方程以及机械臂末端抓手的线速度与关节铰速度间的动力学Ｊａｃｏｂｉ关系。     

A rate control scheme for H.264 video under low bandwidth channel

INTRODUCTION Rate control has been playing an increasing important role in real-time video communication. An encoder employs rate control to regulate output bit- streaming to meet certain channel bandwidth and buffer constraints while pursing high video quality. One fundamental problem in the encoder design is the selection of quantization parameter (QP) to maximize visual quality under constraints imposed by the computational complexity, delay, bandwidth and/or loss factors. At present…     

金家庄螺旋隧道施工通风方案优化数值模拟

本文以金家庄特长螺旋隧道为依托,运用三维数值计算方法,采用风仓与隔板风道组合式通风方案对既有压入式进行优化.研究表明:(1)采用既有方案,第一、二阶段均不能满足供风量要求,采用优化方案可满足要求,且风机总功率最大降低58％;(2)第二阶段通风,既有方案最多同时向两个掌子面供风,优化方案最多同时向三个掌子面供风,加快施工...     

异步电机矢量控制系统仿真研究

异步电动机是一个高阶、非线性、强耦合的多变量系统.文中提出一种异步电动机矢量控制系统方案,并在此基础上设计了一个典型的矢量控制系统,然后利用matlab/simulink仿真软件对该控制系统进行建模与仿真研究.     

Proportional integral plus multi-frequency resonant current controller for grid-connected voltage source converter under imbalanced and distorted supply voltage conditions

This paper proposes a current control scheme for a grid-connected pulse width modulator （PWM） voltage source converter （GC-VSC） under imbalanced and distorted supply voltage conditions. The control scheme is implemented in the positive synchronously rotating reference frame and composed of a single proportional integral （PI） regulator and multi-frequency resonant controllers tuned at the frequencies of 2ω and 6ω, respectively. The experimental results, with the target of eliminating the active power oscillations and current harmonics on a prototype GC-VSC system, validate the feasibility of the proposed current control scheme during supply voltage imbalance and distortion.     

异步电机按定子磁链定向的转矩连续控制

ＮｏｍｅｎｃｌａｔｕｒｅＪｍｏｍｅｎｔｏｆｉｎｅｒｔｉａｏｆｔｈｅｌｏａｄ(ｍｏｔｏｒｉｎｃｌｕｄｅ)ｉｓ,ｉｒ,ｉｍｓｔａｔｏｒ,ｒｏｔｏｒａｎｄｍａｇｎｅｔｉｚｉｎｇｃｕｒｒｅｎｔｕｓ,ｕｒｓｔａｔｏｒａｎｄｒｏｔｏｒｖｏｌｔａｇｅＬｓ,Ｌｒ,Ｌｍｓｔａｔｏｒ,ｒｏｔｏｒａｎｄｍａｇｎｅｔｉｚｉｎｇｉｎｄｕｃｔａｎｃｅＬσｔｏｔａｌｌｅａｋａｇｅｉｎｄｕｃｔａｎｃｅＲｓ,ＲｒｓｔａｔｏｒａｎｄｒｏｔｏｒｒｅｓｉｓｔａｎｃｅＮｐｐｏｌｅｐａｉｒｓΨｓ,Ψｒ,Ψσｓｔａｔｏｒ,ｒｏｔｏｒａｎｄｔｏｔａｌｌｅ…     

高功率因数的调宽式开关整流器

介绍一种新的单相开关整流器的控制方案,它采用有源电流波形整形技术来控制输入电流连续导通,其控制开关的周期是固定的,导通时间的大小是根据输入电流的斜率进行调控。论述该控制方案具有不需要电流传感器、线路功率因数高、电路简单等特点。理论分析和实验结果证明了该控制方案是可行的。     

负载平衡控制器设计

文章提出了一种用模糊控制器作为两台直流驱动电动机同轴运行的负载平衡控制器的方案.该方案不仅使系统具有较快的响应速度,而且也有良好的控制精度.     

制造机器人PLC控制系统的设计

设计了一种基于PLC的制造机器人控制系统,能够应用于制造业流水线的加工应用,提高生产效率。详细阐述了该控制系统的设计原理、组成结构和实现方案。重点研究了基于PLC控制原理的详细设计方案,给出了基于PLC控制过程的基本流程、控制系统的接口描述和控制系统中资源描述与分配方法。     

交通信号灯的PLC控制系统设计

文章针对城市交通道路十字交叉路的交通灯信号控制存在的问题进行了探讨,提出由PLC承担主要控制任务的新方案,该方案具有编程简单易维护的特点,能够有效减少交通事故,改善道路交通环境。并借助瑞新公司PLC实验设备对控制程序进行了模拟运行、演示,证明了该控制系统的可行性。     

Dynamic modeling and direct power control of wind turbine driven DFIG under unbalanced network voltage conditions

This paper proposes an analysis and a direct power control （DPC） design of a wind turbine driven doubly-fed induction generator （DFIG） under unbalanced network voltage conditions. A DFIG model described in the positive and negative synchronous reference frames is presented. Variations of the stator output active and reactive powers are fully deduced in the presence of negative sequence supply voltage and rotor flux. An enhanced DPC scheme is proposed to eliminate stator active power oscillation during network unbalance. The proposed control scheme removes rotor current regulators and the decomposition processing of positive and negative sequence rotor currents. Simulation results using PSCAD/EMTDC are presented on a 2-MW DFIG wind power generation system to validate the feasibility of the proposed control scheme under balanced and unbalanced network conditions.     

基于DDC与变频技术的净化空调控制系统的设计

GMP对制药厂房的空气质量指标有着严格的要求,而净化空调系统是保证洁净厂房内空气质量的最主要的设备。为了提供净化空调系统的管理,本文整合了DDC控制技术与变频调节技术,提出了在净化空调中采用DDC和变频器进行控制的方案,该方案既可净化空气的各项指标达到GMP的要求,保证净化厂房内的洁净度,又可保证空调系统有效、节能运转。     

具有故障诊断特色的测控专业建设探索

测控专业涉及多学科知识,需要培养学生融会贯通,解决问题的能力。文章提出具有故障诊断特色的测控专业建设方案,包括修订培养方案、建设故障诊断理论课程、设计故障诊断实验课程等。经过多年探索和实践,取得很好的教学效果,学生的实践创新能力有较大提升。     

矿井提升机超同步串级调速控制研究

针对晶闸管串级调速控制系统存在的问题,提出了采用定子磁场定向的矢量控制技术的双PWM整流器的双馈串级调速方案,确定了整流器调制度,详细分析了系统运行过程。     

基于Web的远程可视化教学系统设计

提出了一种基于Web模式的远程可视化教学系统的解决方案。研究了方案所采用的关键技术,包括视频传输、ActiveX插件技术、Java技术、Socket技术和网络安全等,充分发挥了Java在网络编程、跨平台等方面的优势和c 语言在底层设备控制方面的优势。     

热轧钢带冷却过程建模及自动控制研究

通过研究热轧钢带的冷却过程,对其温度的变换进行了建模分析。根据所建立了数学模型,提出了基于反馈控制原理的温度控制方案,给出了反馈卷取温度控制的详细控制过程,最后结合实际的工作特点,对模型进行了分析与修正。     

A scalable admission control scheme based on time label

INTRODUCTION The current Internet only provides a simplebest effort service where the network treats all datapackets equally. In this manner, the network keepssimple so that it can scale. Best effort service issufficient for traditional Internet applications, suchas email and web browse. But, with the advent ofvoice/video stream media and other real-time ap-plications over the Internet, there is great demandfor enhanced service on the Internet. IntServ (Braden et al., 1997) …     

A scalable admission control scheme based on time label

Resource reservation protocols allow communicating hosts to reserve resources such as bandwidth to offer guaranteed service. However,current resource reservation architectures do not scale well for a large number of flows. In this paper,we present a simple reservation protocol and a scalable admission control algorithm,which can provide QoS guarantees to individual flows without per-flow management in the network core. By mapping each flow to a definite time,this scheme addresses the problems that limit the effectiveness of current endpoint admission control schemes. The overall admission control process is described. Analysis is used to explain the reasonability of our scheme and simulation validates its performance.     

低开关损耗SVPWM整流器的实现

提出一种将两相调制技术应用于SVPWM整流器从而获得低开关损耗的控制算法,基于TMS320F240 DSP进行数字实现,并验证了可行性。