煤矿井下无源光网络的研究与应用

无源光网络(PON)在电信网中已得到广泛应用,但用于煤矿井下综合自动化网络平台则是刚刚起步.本文介绍了无源光网络的发展过程、EPON的工作原理、以及利用EPON技术构建的煤矿井下综合自动化传输平台的系统原理、系统结构、系统特点和主要技术指标.煤矿GEPON系统的建设为矿井各种子系统的建设接入提供了一个高速、安全、稳定的平台.该平台是矿井信息传输技术的一个突破,代表着国内领先水平.随着GEPON系统在煤炭系统的推广应用,其必将为我国煤矿安全生产提供更加可靠的保障.     

wifi网络通讯技术在煤矿井下的应用分析

大量开挖煤矿,使得煤矿井下的工作环境越来越复杂,给井下作业的无线通讯和监测带来了难题,影响了井下作业的工作效率和安全性。而Wifi无线网络通讯技术的日益发展和成熟则为这一问题带来了行之有效的解决办法。文章简单介绍了Wifi技术,并通过Wifi无线通讯技术与以往井下的无线通讯技术的比较,阐述了Wifi技术在井下无线通讯中的优势,分析了Wifi网络通讯技术在煤矿井下的应用,论述了这一技术对井下无线通讯的重要意义。     

RFID技术在井下人员定位系统中的应用研究

井下人员定位系统是井下安全避险六大系统的重要组成部分。本文介绍了RFID技术在浙江绍兴平水矿业公司井下人员定位系统中的应用,详细描述了系统工作原理、硬件配置和软件功能设计。井下人员定位系统实际运行结果表明,保障了井下工作人员的安全,提高了企业的管理水平和安全生产效率。     

基于Comsol的井下瞬变电磁传感器建模与仿真

井下传感器是测井工作中必不可少的组成部分,传感器的性能直接影响井下探测的准确性和测井解释的精确性.为了进一步提高井下传感器的灵敏度,本文以瞬变电磁理论为基础,以Comsol Multiphysics仿真软件为工具,建立了井下传感器探测的几何模型,通过添加物理场,网格剖分,求解了井下传感器的磁场分布,分析了探头尺寸、激励电流和线圈匝数等参数对井下传感器探测性能的影响.研究结果对井下传感器的优化设计具有一定的参考价值.     

国内煤矿无线电通信技术的综述和展望

概述了国内煤矿井下无线通信系统的现状,介绍了煤矿井下目前使用的无线通信系统的性能和特点,并对井下无线通信系统的发展趋势进行了分析。     

煤矿井下供电监控系统设计研究

煤矿井下作业是一项特殊工作,井下供电检测监控尤为重要.煤矿井下供电监控系统的设计是搞好煤矿井下电力设备运行工作的基础环节,监控系统的设计合理与否关系到井下工作的顺畅与否,进一步关系到井下工作的工作人员的生命安全,在煤矿企业工作中意义重大.本文在概述煤矿井下供电监控系统的基础上,研究了供电监控系统的重要作用和设计应用.     

基于WiFi技术的井下无线通信系统设计

基于WiFi无线通信技术逐渐在井下通信中应用。通过分析井下以及灾害救援工作的紧迫性与安全性,阐述了无线通信技术在井下应急救援无线通信系统中的重要性,提出研发无线网井下应急救援通信系统的方法。     

综合数字通信在煤矿井下安全生产中的应用

前言 随着现代通信技术的发展,煤矿井下通信也发生了很大变化,数字程控调度交换机已大量应用于煤矿井下通信,极大地改善了煤矿井下安全生产指挥系统,但这远远不能满足现代化矿山建设的需求。虽然目前井下也建了一些视频监控和瓦斯监测系统,但它们还是单一网络,同时全国乃至全世界对井下井形井貌及次声波都没有进行监测。     

计算机网络技术在煤矿井下区域性探测的数据分析

煤矿井下探测工作因为其特殊的行业特点和自身特色,目前已有其他部门、行业、以及其他国家的探测系统无法直接应用。文章根据对象分析法,结合了GIS信息化技术对煤矿井下区域性探测进行了分析,认为分析井下区域性探测系统信息化设计的关键在于对煤矿井下GIS探测的表达,应用数据分析技术,最后面向对象数据模型,利用煤炭井下区域性探测及分布联系建立了计算机数据分析系统CPFR模型。     

井下干式变压器常见故障及维修工作分析

井下干式变压器是矿区电力系统运行的主要设备,其实现能量转换的核心设备,其质量及运行状态直接影响了矿区的整体作业水平。本文阐述了井下干式变压器及其发展,简要分析了井下干式变压器常见故障,对针对井下干式变压器常见故障的解决对策及检修方法进行深入探究。     

煤矿井下光纤工业电视监视系统

煤矿井下光纤工业电视针对井下环境设计，采用本安型、低照度光纤摄象仪，以光纤作为传输介质，具有传输距离远、图像清晰、不受电磁干扰等优点。工业电视控制器和用户遥控仪组成功能很强的监视系统，每个用户均可控制各自监视器上的图像显示，互不影响。矿调度人员及有关决策领导在各自办公室即可了解井下生产情况，对指挥生产、抢险救灾起到重要作用。本文给出硬件设计。     

残留边带调幅光缆电视光纤传输系统中的频道容量

与传统的电缆电视系统相比，残留边带调幅光缆电视光纤传输系统具有很大的优越性，因而对该系统的研究具有重要的产用意义。文中对ＭＡ－ＶＳＢＣＡＴＶ光纤传输系统的频道容量及其相关因素作了探讨，并导出了一些相关的计算公式。     

A coherent optical FDM CATV distribution system

A coherent optical frequency-division-multiplexing (FDM) experimental system for an optical CATV distribution service has been developed. This system employs a channel frequency spacing locked optical FDM transmitter and a random access optical heterodyne receiver. In the transmitter, ten 1.54-μm wavelength tunable distributed-Bragg-reflector laser-diode (DBR LD) modules were FSK modulated with a 400-Mb/s PN pattern. A reference pulse method is used for channel space control. Individual channel spacings for ten LDs are stabilized to 8 GHz. The random access optical heterodyne receiver is realized with a wavelength tunable local DBR LD, polarization diversity reception technique, and random access automatic frequency controller. A current address method realizes the random access function. The results of a ten-channel FDM transmission experiment carried out to evaluate these techniques are presented. It is estimated that over 80 channel high-definition TV signals can be distributed to 2000 subscribers with 500-GHz frequency tunable DBR LD. The feasibility of expanding the subscriber number to over 10000 was confirmed by an experiment with a traveling-wave optical amplifier     

南宁高铁首条1550 nm 有线数字电视单纤双波实施方案及探讨

探讨了在单芯光纤中,通过“公共通道无源化,有源设备冗余化”的设计理念,采用密集波分复用（ DWDM）技术、掺铒光纤放大技术、光信号自动切换技术,结合SBS抑制技术和色散补偿技术,实现高可靠冗余热备份数字电视传输网络的设计,与传统的数字电视传输系统相比,具有链路简单、中间环节少、结构模块化、故障影响面小等特点。     

论基于HFC网络结构的演变

随着业务需求的增长,要求网络带宽越来越宽。有线电视HFC网络正在急速演变,其同轴电缆部分将逐步缩短,使其有利于语音、数据和视频信息的综合传输。交互电视、VOD、IP应用正在被人们看好,为实现用户的高比特率双向传送,HFC网络必须改造成光纤到大楼、光纤到家庭的结构。     

12300 ps/nm, 2.4 Gb/s nonregenerative optical fiber transmissionexperiment and effect of transmitter phase noise

A nonregenerative optical transmission experiment with a chromatic dispersion of more than 10000 ps/nm is reported. Externally intensity-modulated 2.4 Gb/s optical signals were transmitted over 710 km of nondispersion-shifted optical fiber using ten Er-doped fiber amplifiers with a total net optical gain of 125 dB. Although the total chromatic dispersion amounted to 12300 ps/nm, the power penalty observed was as small as 0.5 dB, and an error floor was not observed. The effect of transmitter phase noise associated with fiber chromatic dispersion was experimentally investigated     

衡阳九运会电子火炬启动电视直播系统设计

介绍了衡阳市第九届运动会电子火炬传递启动仪式直播中的多点实时传输系统。分别介绍了视频系统、远程传输系统、通话系统、音频系统的配置情况与连接图。阐述了光纤传输、3G传输系统在城市台中的实际使用情况以及两种传输方式相结合使用的系统结构和搭建。     

An Optical Communication System Using Envelope Modulation

A wide-band optical communication system that modulates the envelope of the carrier of a high-speed optical pulse having no relation to the PCM signals, was developed. This optical pulse is supplied from a He-Ne gas laser oscillator that is controlled to generate a single transversal mode. The transmission bit rate of this optical communication system is 123 Mbits/s, and this system has a transmission capacity of three monochrome video signals, three program signals, and one channel of 48-kHz high-speed facsimile signal or one National Television System Commission (NTSC) color TV signal and one program signal. When this optical communication system is used to propagate through the atmosphere for a distance of 2-3 km, reliability is expected to be 99 percent.     

Fiber-optic digital video distribution system for usinghigh-definition television signals using laser-diode optical switch

A fiber-optic high-definition television (HDTV) distribution system is discussed, which economically distributes HDTV signals to customers at a bit rate of about 100 Mb/s. The subscriber network is formed in a star topology to facilitate bidirectional connection. The distribution system uses digital video transmission at 1.3 μm wavelength using single-mode fiber. The video channel selection is made by an optical video selector. The optical selector consists of laser diode optical switch modules, which have a gain in the `ON' state and two-input, two-output 3 dB couplers. The authors describe the bit error rate characteristics of a signal-mode fiber digital distribution system using a four-input, one-output optical selector     

Optical Fiber Supertrunking--A Performance Report on a Real-World System

This is a review of a Specific application for video interconnection on single-mode optical fiber Over a 13.9 mi path, covering system design, aerial and underground plant construction, terminal equipment selection, and operating results. Both digital and analog circuits are used in the system, and the economics and performance of the two approaches are compared. The digital equipment in installed transports four video Channels on a single-mode fiber using both 1300 nm and 1550 nm lasers, and the analog system is tested transperting both 8 and 12 channels per fiber. To explore the potential of the system, tests are run on a fiber path 27.8 mi (44.7 km) in length. Using actual costs, an updated economic comparison between fiber optic systems and FM video coaxial systems is made. The conclusion is drawn that analog fiber video transmission systems have been developed to the point where they offer economics and performance generally superior to, and reliability substantially better than, FM video coaxial systems. Both analog and digital fiber systems are shown to be capable of excellent quality video transmission through a path loss of over 25 dB.