摘要在矿井电力网系统中，防止发生漏电事故是一项极其重要的保护措施，因为漏电可以称为是煤矿井下供电系统中的主要故障类型之一，在所有的故障之中，漏电事故大约会占到故障次数之和的70%以上。发生频繁是漏电事故的一大特征也是其需要我们重点防止的原因之一，此外，它还会引起诸如人身触电事故等形式的更加严重的危害，对人的生命财产安全造成巨大威胁，不仅如此，由于漏电事故会形成单相接地，进而会造成相和相之间的短路故障，扩大了故障损失，如果不加以防治，最终会引起煤尘、瓦斯等煤矿井中的易燃气体的爆炸，危害巨大。为了防止漏电事故所引发的各类损失，漏电保护就成了大家不得不探讨的一项严峻任务，如果漏电保护措施完善，便可以有效地防治漏电引起的火灾、爆炸等，极大地减少了煤矿井下生产和生活过程中的经济损失和人员伤亡。在当今社会，随着煤矿井下科学技术的不断发展和日益完善，漏电保护在实际的生产生活中得到了更加广泛的应用。71698

本文设计了基于功率方向保护和傅立叶变换法，克服了两种原理的缺点，利用了他们的优点。本设计基于89C51型单片机控制，通过两种方法的基本动作，互相配合，优势互补，实现了较为可靠的选择性漏电保护。本篇论文的第一章主要介绍了漏电保护的意义，发展历程及论文的主要内容。第二章主要对矿井选择性漏电保护进行理论分析，第三章为电路的硬件设计部分，第四章为电路的软件开发部分，最后为本篇设计的总结。本设计在电网正常运行时,可实现对电网绝缘电阻的连续检测;当人身触电或发生漏电故障时，可迅速切除电源；电网的绝缘电阻均匀下降时,也可将此故障检测出来，故具有实用价值和研究意义。

该论文有图23幅，表0个，参考文献8篇。

毕业论文关键词：多重保护  选择性  互相配合 

 Selective leakage protection in coal mine

Abstract In mine power network system, first of all, we should  prevent the occurrence of leakage accident, because the leakage is the main failure form of underground power supply system.  Not only is the leakage accidents frequently occur but it will lead to more serious accident of human electric shock ,to people's life and property safety caused a great threat as well.In addition, leakage accident will form single-phase grounding accident, and development phase to phase short circuit, gas and coal dust explosion easily triggered, great harm. In order to prevent the leakage accidents caused by the loss of all kinds, the leakage protection arises at the historic moment, which is mainly used for preventing leakage fire caused economic loss and personnel casualties.With the development of science and technology, leakage protection in actual production and life has been widely used.

Is designed in this paper based on power direction protection and the Fourier transform method and overcome the shortcomings of two principle, take advantage of them. The design based on 89C51 MCU control, through the basic action of two kinds of methods, cooperate with each other, complementary advantages, to achieve a more reliable and selective leakage protection. The system in the normal operation of the network, can carry out continuous examination on the grid insulation resistance; when the human body electric shock, leakage failure, can quickly cut off the power supply; power grid insulation resistance decreased uniformly, the fault detection.

Key Words: Leakage Protection   Selectivity  Mutual Coordination   

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