协调控制在350MW超临界CFB机组中的运用

现以某公司350 MW超临界CFB机组为例,介绍了其协调控制系统中负荷指令回路、锅炉主控回路、汽机主控回路的控制策略。     

PLC控制液压回路快速组合实验台设计

采用PLC作为实验台电控系统的主控器,可以快速组合所设计的液路和电路,并进行多种常规的液压回路实验。介绍该实验台的工作原理、特点和应用。     

基于QCS003B的节流调速性能的实验研究

采用QCS003B型液压实验台对节流调速回路速度和负载数据进行采样,并利用这些实验数据对进油路节流调速回路、回油路节流调速回路及旁油路节流调速回路的速度负载特性进行了实验性研究。研究表明节流调速回路的实验结果与理论分析基本吻合。     

基于HCNR201的高精度模拟信号隔离电路设计

为解决煤巷掘进过程中的探掘矛盾,研制了基于双频激电法和电场聚焦偏转效应的矿用聚焦双频激电仪。该仪器要求输出单路幅值可控、5路相互隔离的双频调制方波电流,同时完成输出电压电流值的高精度隔离采样。论文深入分析了基于线性光耦HCNR201的高精度线性隔离放大器的工作原理,从理论上推导了电压传递函数关系;提出了矿用聚焦双频激电仪隔离电路设计方案,完成了高精度模拟信号隔离电路设计(包括输出电压电流隔离采样电路及电压隔离控制电路)。通过搭建电压隔离采样电路并对其测试结果精度进行分析,表明该电路可实现0~2.5 V直流电压信号的高精度采集。     

无源4～20mA线性光电多路隔离电路

针对目前工业常用的4~20mA信号的隔离转换,本文提出了一种采用电源窃电技术并使用普通光耦实现4~20mA无源线性隔离转换的电路,经过理论分析计算并试验验证,电路结构简单,线性度好,成本低,对被检测回路影响小,可实现单路或多路隔离转换4~20mA输出。     

智能变电站二次回路隔离措施分析

对智能变电站二次回路隔离措施展开深入研究,能够避免运检人员操作不符合相应标准进而造成的保护误动情况、保护拒动情况的发生,有效起到隔离效果。为提高智能变电站设备运作的使用效率,让其运行更平稳、持续,本文主要分析针对于智能变电站二次回路采取的主要隔离措施:SV回路的隔离措施、GOOSE回路和投退原则。     

电容式六维力与力矩传感器数据采集系统设计

为实现电容式六维力与力矩传感器测量力与力矩信息的实时采集和显示,针对实验室自主研制的电容式六维力与力矩传感器开发了一套数据采集系统。系统以STM32F103C8T6作为主控芯片,电容信号经AD7147采集并转换为数字信号,转换结果经隔离型SPI通讯传输到主控芯片后,主控芯片通过基于Modbus协议的RS485通讯发送给上位机。上位机采用WinForm界面进行设计,能对数据进行进一步标定计算处理,并最终实现所测量力与力矩值的实时显示与保存。经过实验测试,采集系统的测量值和实际加载的力与力矩值的测量误差低于3%。该系统的采样精度高、开发成本低且上位机功能完善,为电容式六维力与力矩传感器的应用研究提供了重要的信息。     

基于A3P125的多路数据采编与存储测试系统

文中主要介绍针对不同采样频率的多路数据的采集与存储方法.重点阐述了基于A3P125型FPGA的多路数据采集与存储测试系统的编帧、方案设计、硬件电路及软件电路设计方法,并且介绍了对于该系统的一种软件自测方法.实验测试结果表明:该设计系统能很好地完成多路的采集,其采集精度1%,采样路数可以根据需要进行扩展.     

适用于PEBB采样系统的高速光纤隔离通讯装置

为了解决系统中较高电压电流变换率对采样产生的干扰问题,提出一种基于现场可编程门阵列(FPGA)的光纤隔离采样通讯装置,并阐述了该装置的具体设计思路及步骤.这种装置可实现信号采样并进行数字化传输和接收,具有优良的绝缘性能和暂态特性,对复杂电力电子系统隔离采样及信号传输有工程实用价值.最后通过实验给出了两个节点间数据传输波...     

基于单片机的高效光伏电源管理系统

设计了一种高效光伏电源管理系统,该系统以单片机为主控制器,外围包括蓄电池电压采样电路,蓄电池充电、放电电流采样电路,光伏电池的输出电压采样电路,光伏电池输出电流采样电路,DC—DC变换电路等,相互配合实现光伏电源系统的管理：一方面,系统采用最大功率点跟踪的方法使光伏充电系统输出功率最大,高效利用太阳能;另一方面,对蓄电池的充放电进行过充、过放控制,有效保护蓄电池,延长其使用寿命。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.