【作者】 王文华；

【导师】 宋建成；

【作者基本信息】 太原理工大学 ， 电机与电器， 2010， 硕士

【摘要】 随着煤炭工业的发展和采煤自动化技术的不断提高,对煤矿井下供电系统的可靠性、安全性和连续性提出了越来越高的要求。矿用低压馈电开关是煤矿井下低压电网中的关键配电设备,其性能好坏直接影响着煤矿生产的安全性和连续性,而矿用低压馈电开关的智能化程度主要取决于保护系统的可靠性和灵敏性。因此对矿用低压馈电开关综合保护系统的研究具有重要的现实意义。本文在查阅国内外文献的基础上,系统地研究了基于PLC控制的矿用低压馈电开关综合保护系统,主要内容如下:首先分析了煤矿井下供电系统的特点,介绍了国内外矿用低压馈电开关的发展情况,指出了目前矿井低压电网保护所存在的问题,并根据《煤矿安全规程》规定,给出了矿用低压馈电开关综合保护系统的基本要求。根据保护系统的技术要求,系统地分析了低压电网中漏电、短路、过载、过压与欠压等常见故障的产生原因和故障特征,并介绍了相应的故障检测原理。在简单介绍了PLC的发展与特点的基础上,选定了PLC作为中央控制单元,并设计了系统的硬件电路,主要包括选择性漏电保护电路、相敏保护电路、负序保护电路和有功功率检测电路。实验结果表明:硬件电路采样准确,动作灵敏,能够可靠反映电网的运行状态。在软件构建中,采用了模块化设计方法,设计了监控主程序和各功能模块子程序。实验结果表明:软件程序执行效率高,运行稳定,运算准确。作为馈电开关重要组成部分的人机界面,本文叙述了馈电开关人机界面的设计过程,包括人机界面设备的选择、软件开发环境的介绍和页面功能设计。实验结果表明:人机界面友好,显示准确,运行稳定,可操作性强。根据矿井电网的实际特点,分析了矿用低压馈电开关综合保护系统的主要干扰源及其特征,针对不同的干扰信号,制定了相应的硬件和软件防治措施,提高了保护系统工作的可靠性。本文所设计的矿用低压馈电开关综合保护系统经过了实验室初步试验,试验结果表明:该系统能够准确、可靠、快速地反映电网的运行状态并执行相应操作,证实了设计方案的正确性与可行性。更多还原

【Abstract】 With the rapidly development of coal industry and the continuous improvement of mining automation, it is demanded that the underground power supply system must be of the higher reliability, security and continuity. Underground low voltage feeder switchgear plays center role in the coal mine low voltage power network. The capability of it directly affects the security and efficiencies in coal production. But the intelligence level of underground low voltage feeder switchgear mainly depends on the reliability and sensibility of protection system. Hence it is important to develop a new measurement and control system in underground low voltage feeder switchgear.On the basis of consulting internal and external documents, the synthesis protection system in underground low voltage feeder switchgear has been researched in detail based on PLC in this thesis as following:First of all, the characteristics of coal mine LV power supply system are analyzed, and the developing histories of underground low voltage feeder switchgear at home and aboard are reviewed. In addition, the disadvantages of traditional synthesis protection system are pointed out. Based on the rules of“Safety Regulation of Underground Coal Mines”, the technical requirements are put forward in the thesis.According to the technical requirements of the protection system, the cause and fault characteristics of earth leakage, short circuit, over-load, over voltage and under voltage are theoretically analyzed, and the principle of fault detection are also introduced.Based on the introduction of PLC development and characteristic, PLC is used as the control core, and the hard circuits are designed also, including selective leakage protection circuit, phase-sensitive measurement circuit, negative sequence protection circuit and active power measurement circuit. It has been shown by the result that the circuits sample accurately, run steadily and detect the running state of power network.In the software construction, module programming design method is used, host monitor procedure and functional subprograms are compiled. It has been shown by the result that the programs compute accurately, run efficiently and operate steadily.The development process of man-machine interface is described in detail, including the choice of man-machine interface device, the introduction of software development environment and the program design. It has been shown by the result that the man-machine interface is friendly, accurate and easy to operate.According to the actual environment in the coal mine power network, the sources and features of interference signals are discussed. Based on the analyzed characteristics of interference sources in underground, the corresponding hardware and software measures of anti-interference are taken to increase the reliability of the monitoring system.The protection system has been tested in the laboratory. The results indicate that the system detect the running state of power network accurately, steadily and rapidly, and execute relevant operations. It has been proved by the mention above that the control scheme is correct and practical.更多还原