【作者】 郝俊芳；

【导师】 宋建成；

【作者基本信息】 太原理工大学 ， 电力电子与电力传动， 2002， 硕士

【摘要】 电磁起动器是煤矿井下供电系统中的关键设备之一，它的工作可靠性直接影响煤矿的生产和供电系统的安全，因此开发研制高性能的电磁起动器测控系统，对提高矿井供电系统的可靠性、安全性、连续性，具有非常重要的现实意义。本文介绍一种新型隔爆兼本质安全型智能电磁起动器测控系统，它是在对井下异步电动机保护系统研究的基础上，同时为了适应现代矿井的要求而设计的。系统采用单片机控制技术，完成所控制电动机的控制功能，并对所控制电动机的电压、电流等信号进行检测、计算、判断和处理，实现短路、断相、过载、欠压、过压、过热、漏电闭锁等保护功能，并提供本质安全型输入、输出接口，能与煤矿井下监测监控系统联网运行。 论文首先分析了感应电动机的起动过程和不对称运行情况下的故障特征，从理论上为测控系统提供了设计依据。在此基础上提出了将相敏保护原理和负序保护原理应用于测控系统中，它不仅可以提高保护的灵敏度而且还可以扩大保护范围。根据煤矿安全规程规定设计了性能完善的本质安全型先导电路，起动前它能有效地防止因控制线接地造成自起动现象的发生，而且在运行中无论控制线发生短路、断线还是接地故障，它均能可靠跳闸，确保生产的安全，该先导电路的性能指标达到了国内领先水平。 根据矿井电网的实际情况，分析了所存在的干扰源及所产生干扰信号的基本特征。针对各种干扰信号，设计并采用了硬件结合软件的抗干扰措施，有效地提高了测控系统的工作可靠性和连续性。 本文所研制的智能型电动机保护系统样机性能通过了实验室模拟试验。短路保护既能躲过起动电流，又有较高的灵敏度；不平衡保护，能准确区分不对称短路和断相故障；其它保护功能的动作指标均达到了设计要求。试验证明，该测控系统性能稳定，动作可靠，具有广阔的应用前景。更多还原

【Abstract】 Electric magnetic starters is a kind of important electrical equipments in underground distribution networks, which reliability directly effect the production of mine and the safety of power supply system, thereby it is of important realism signification to develop a high-powered measurement and control system of electric magnetic starters for improving the reliability, safety and continuity of the power supply systems. A new measurement and control system (MCS) of flameproof and intrinsically safety intelligent electric magnetic starters is introduced in this thesis. Based on the research of the protective systems for underground asynchronous motors, the measurement and control system has been designed in order to satisfy the demands of modern mines. The single-chip microcomputer control technology has been applied in the system to carry out monitoring and protective functions for the asynchronous motors controlled. Combined with suitable peripheral interface, disposition and flexible software, the MCS can measure the current and voltage signals of the motors. Based on the measurements, the computation, judgment and decision are made to implement the phase sensitive short circuit, overload, supply over-voltage, supply under-voltage, over-thermal, leakage lock-out and loss of phase protective function. In addition, the MCS provides intrinsically safe input and output interface, which can be connected with the monitoring system for the underground power networks.First of all, the starting process and failure characteristics of asynchronous motors under unbalanced operation condition are analyzed in the paper, which provides theoretical foundation for the design of the system. On the basis of these mentioned above, it has been proposed that the principle of phase-sensitive protection and negative sequence protection can be used in the system, which can not only improve the sensitivity of the protective system but also extend the protection range in underground distribution networks. According to the rule of Mine Safety Regulations, an intrinsically safe pilot circuit with perfect performance for underground motor intelligent protective systems is put forward, which can effectively avoid the phenomenon of self-starting that is caused by the earthing of control lines before starting motors, at the same time, can reliably cut off the switches to ensure the safety of underground production under operation condition no matter what the faults ofshort circuit, open circuit and earthing in the control circuits happened. It has been found that the performance and technical parameters of the system has come up to advanced world standards by literature search.According to the practical instance of underground distribution networks, the basic characteristics of interference signals produced by interference sources existing in the networks are also analyzed in the paper. The anti-interference measures have been taken in accordance with the interference signals, which has effectively improved the reliability and continuity of the measurement and control system.The measurement and control system designed in this thesis has been tested in laboratory. It has been verified by simulation tests that the symmetric short-circuit protection can not only avoid the starting current but also achieve higher sensibility; unbalance protection can distinguish unbalance short-circuit and loss of phase. The operation parameters of other protective functions has all reached the design requirements. It has been concluded that the measurement and control system is stable, reliable and is of great applied value in underground distribution networks.更多还原